/*
* DPP functionality shared between hostapd and wpa_supplicant
* Copyright (c) 2017, Qualcomm Atheros, Inc.
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "utils/includes.h"
#include <openssl/opensslv.h>
#include <openssl/err.h>
#include "utils/common.h"
#include "utils/base64.h"
#include "utils/json.h"
#include "common/ieee802_11_common.h"
#include "common/ieee802_11_defs.h"
#include "common/wpa_ctrl.h"
#include "crypto/crypto.h"
#include "crypto/random.h"
#include "crypto/aes.h"
#include "crypto/aes_siv.h"
#include "crypto/sha384.h"
#include "crypto/sha512.h"
#include "dpp.h"
#if OPENSSL_VERSION_NUMBER < 0x10100000L
/* Compatibility wrappers for older versions. */
static int ECDSA_SIG_set0(ECDSA_SIG *sig, BIGNUM *r, BIGNUM *s)
{
sig->r = r;
sig->s = s;
return 1;
}
static void ECDSA_SIG_get0(const ECDSA_SIG *sig, const BIGNUM **pr,
const BIGNUM **ps)
{
if (pr)
*pr = sig->r;
if (ps)
*ps = sig->s;
}
#endif
static const struct dpp_curve_params dpp_curves[] = {
/* The mandatory to support and the default NIST P-256 curve needs to
* be the first entry on this list. */
{ "prime256v1", 32, 32, 16, 32, "P-256", 19, "ES256" },
{ "secp384r1", 48, 48, 24, 48, "P-384", 20, "ES384" },
{ "secp521r1", 64, 64, 32, 66, "P-521", 21, "ES512" },
{ "brainpoolP256r1", 32, 32, 16, 32, "BP-256", 28, "BS256" },
{ "brainpoolP384r1", 48, 48, 24, 48, "BP-384", 29, "BS384" },
{ "brainpoolP512r1", 64, 64, 32, 64, "BP-512", 30, "BS512" },
{ NULL, 0, 0, 0, 0, NULL, 0, NULL }
};
/* Role-specific elements for PKEX */
/* NIST P-256 */
static const u8 pkex_init_x_p256[32] = {
0x56, 0x26, 0x12, 0xcf, 0x36, 0x48, 0xfe, 0x0b,
0x07, 0x04, 0xbb, 0x12, 0x22, 0x50, 0xb2, 0x54,
0xb1, 0x94, 0x64, 0x7e, 0x54, 0xce, 0x08, 0x07,
0x2e, 0xec, 0xca, 0x74, 0x5b, 0x61, 0x2d, 0x25
};
static const u8 pkex_init_y_p256[32] = {
0x3e, 0x44, 0xc7, 0xc9, 0x8c, 0x1c, 0xa1, 0x0b,
0x20, 0x09, 0x93, 0xb2, 0xfd, 0xe5, 0x69, 0xdc,
0x75, 0xbc, 0xad, 0x33, 0xc1, 0xe7, 0xc6, 0x45,
0x4d, 0x10, 0x1e, 0x6a, 0x3d, 0x84, 0x3c, 0xa4
};
static const u8 pkex_resp_x_p256[32] = {
0x1e, 0xa4, 0x8a, 0xb1, 0xa4, 0xe8, 0x42, 0x39,
0xad, 0x73, 0x07, 0xf2, 0x34, 0xdf, 0x57, 0x4f,
0xc0, 0x9d, 0x54, 0xbe, 0x36, 0x1b, 0x31, 0x0f,
0x59, 0x91, 0x52, 0x33, 0xac, 0x19, 0x9d, 0x76
};
static const u8 pkex_resp_y_p256[32] = {
0x26, 0x04, 0x09, 0x45, 0x0a, 0x05, 0x20, 0xe7,
0xa7, 0x27, 0xc1, 0x36, 0x76, 0x85, 0xca, 0x3e,
0x42, 0x16, 0xf4, 0x89, 0x85, 0x34, 0x6e, 0xd5,
0x17, 0xde, 0xc0, 0xb8, 0xad, 0xfd, 0xb2, 0x98
};
/* NIST P-384 */
static const u8 pkex_init_x_p384[48] = {
0x95, 0x3f, 0x42, 0x9e, 0x50, 0x7f, 0xf9, 0xaa,
0xac, 0x1a, 0xf2, 0x85, 0x2e, 0x64, 0x91, 0x68,
0x64, 0xc4, 0x3c, 0xb7, 0x5c, 0xf8, 0xc9, 0x53,
0x6e, 0x58, 0x4c, 0x7f, 0xc4, 0x64, 0x61, 0xac,
0x51, 0x8a, 0x6f, 0xfe, 0xab, 0x74, 0xe6, 0x12,
0x81, 0xac, 0x38, 0x5d, 0x41, 0xe6, 0xb9, 0xa3
};
static const u8 pkex_init_y_p384[48] = {
0x89, 0xd0, 0x97, 0x7b, 0x59, 0x4f, 0xa6, 0xd6,
0x7c, 0x5d, 0x93, 0x5b, 0x93, 0xc4, 0x07, 0xa9,
0x89, 0xee, 0xd5, 0xcd, 0x6f, 0x42, 0xf8, 0x38,
0xc8, 0xc6, 0x62, 0x24, 0x69, 0x0c, 0xd4, 0x48,
0xd8, 0x44, 0xd6, 0xc2, 0xe8, 0xcc, 0x62, 0x6b,
0x3c, 0x25, 0x53, 0xba, 0x4f, 0x71, 0xf8, 0xe7
};
static const u8 pkex_resp_x_p384[48] = {
0xad, 0xbe, 0xd7, 0x1d, 0x3a, 0x71, 0x64, 0x98,
0x5f, 0xb4, 0xd6, 0x4b, 0x50, 0xd0, 0x84, 0x97,
0x4b, 0x7e, 0x57, 0x70, 0xd2, 0xd9, 0xf4, 0x92,
0x2a, 0x3f, 0xce, 0x99, 0xc5, 0x77, 0x33, 0x44,
0x14, 0x56, 0x92, 0xcb, 0xae, 0x46, 0x64, 0xdf,
0xe0, 0xbb, 0xd7, 0xb1, 0x29, 0x20, 0x72, 0xdf
};
static const u8 pkex_resp_y_p384[48] = {
0x54, 0x58, 0x20, 0xad, 0x55, 0x1d, 0xca, 0xf3,
0x1c, 0x8a, 0xcd, 0x19, 0x40, 0xf9, 0x37, 0x83,
0xc7, 0xd6, 0xb3, 0x13, 0x7d, 0x53, 0x28, 0x5c,
0xf6, 0x2d, 0xf1, 0xdd, 0xa5, 0x8b, 0xad, 0x5d,
0x81, 0xab, 0xb1, 0x00, 0x39, 0xd6, 0xcc, 0x9c,
0xea, 0x1e, 0x84, 0x1d, 0xbf, 0xe3, 0x35, 0xf9
};
/* NIST P-521 */
static const u8 pkex_init_x_p521[66] = {
0x00, 0x16, 0x20, 0x45, 0x19, 0x50, 0x95, 0x23,
0x0d, 0x24, 0xbe, 0x00, 0x87, 0xdc, 0xfa, 0xf0,
0x58, 0x9a, 0x01, 0x60, 0x07, 0x7a, 0xca, 0x76,
0x01, 0xab, 0x2d, 0x5a, 0x46, 0xcd, 0x2c, 0xb5,
0x11, 0x9a, 0xff, 0xaa, 0x48, 0x04, 0x91, 0x38,
0xcf, 0x86, 0xfc, 0xa4, 0xa5, 0x0f, 0x47, 0x01,
0x80, 0x1b, 0x30, 0xa3, 0xae, 0xe8, 0x1c, 0x2e,
0xea, 0xcc, 0xf0, 0x03, 0x9f, 0x77, 0x4c, 0x8d,
0x97, 0x76
};
static const u8 pkex_init_y_p521[66] = {
0x01, 0x4c, 0x71, 0xfd, 0x1b, 0xd5, 0x9c, 0xa6,
0xed, 0x39, 0xef, 0x45, 0xc5, 0x06, 0xfd, 0x66,
0xc0, 0xeb, 0x0f, 0xbf, 0x21, 0xa3, 0x36, 0x74,
0xfd, 0xaa, 0x05, 0x6e, 0x4e, 0x33, 0x95, 0x42,
0x1a, 0x9d, 0x3f, 0x3a, 0x1c, 0x5e, 0xa8, 0x60,
0xf7, 0xe5, 0x59, 0x1d, 0x07, 0xaa, 0x6f, 0x40,
0x0a, 0x59, 0x3c, 0x27, 0xad, 0xe0, 0x48, 0xfd,
0xd1, 0x83, 0x37, 0x4c, 0xdf, 0xe1, 0x86, 0x72,
0xfc, 0x57
};
static const u8 pkex_resp_x_p521[66] = {
0x00, 0x79, 0xe4, 0x4d, 0x6b, 0x5e, 0x12, 0x0a,
0x18, 0x2c, 0xb3, 0x05, 0x77, 0x0f, 0xc3, 0x44,
0x1a, 0xcd, 0x78, 0x46, 0x14, 0xee, 0x46, 0x3f,
0xab, 0xc9, 0x59, 0x7c, 0x85, 0xa0, 0xc2, 0xfb,
0x02, 0x32, 0x99, 0xde, 0x5d, 0xe1, 0x0d, 0x48,
0x2d, 0x71, 0x7d, 0x8d, 0x3f, 0x61, 0x67, 0x9e,
0x2b, 0x8b, 0x12, 0xde, 0x10, 0x21, 0x55, 0x0a,
0x5b, 0x2d, 0xe8, 0x05, 0x09, 0xf6, 0x20, 0x97,
0x84, 0xb4
};
static const u8 pkex_resp_y_p521[66] = {
0x01, 0xb9, 0x9c, 0xc6, 0x41, 0x32, 0x5b, 0xd2,
0x35, 0xd8, 0x8b, 0x2b, 0xe4, 0x6e, 0xcc, 0xdf,
0x7c, 0x38, 0xc4, 0x5b, 0xf6, 0x74, 0x71, 0x5c,
0x77, 0x16, 0x8a, 0x80, 0xa9, 0x84, 0xc7, 0x7b,
0x9d, 0xfd, 0x83, 0x6f, 0xae, 0xf8, 0x24, 0x16,
0x2f, 0x21, 0x25, 0x65, 0xa2, 0x1a, 0x6b, 0x2d,
0x30, 0x62, 0xb3, 0xcc, 0x6e, 0x59, 0x3c, 0x7f,
0x58, 0x91, 0x81, 0x72, 0x07, 0x8c, 0x91, 0xac,
0x31, 0x1e
};
/* Brainpool P-256r1 */
static const u8 pkex_init_x_bp_p256r1[32] = {
0x46, 0x98, 0x18, 0x6c, 0x27, 0xcd, 0x4b, 0x10,
0x7d, 0x55, 0xa3, 0xdd, 0x89, 0x1f, 0x9f, 0xca,
0xc7, 0x42, 0x5b, 0x8a, 0x23, 0xed, 0xf8, 0x75,
0xac, 0xc7, 0xe9, 0x8d, 0xc2, 0x6f, 0xec, 0xd8
};
static const u8 pkex_init_y_bp_p256r1[32] = {
0x16, 0x30, 0x68, 0x32, 0x3b, 0xb0, 0x21, 0xee,
0xeb, 0xf7, 0xb6, 0x7c, 0xae, 0x52, 0x26, 0x42,
0x59, 0x28, 0x58, 0xb6, 0x14, 0x90, 0xed, 0x69,
0xd0, 0x67, 0xea, 0x25, 0x60, 0x0f, 0xa9, 0x6c
};
static const u8 pkex_resp_x_bp_p256r1[32] = {
0x90, 0x18, 0x84, 0xc9, 0xdc, 0xcc, 0xb5, 0x2f,
0x4a, 0x3f, 0x4f, 0x18, 0x0a, 0x22, 0x56, 0x6a,
0xa9, 0xef, 0xd4, 0xe6, 0xc3, 0x53, 0xc2, 0x1a,
0x23, 0x54, 0xdd, 0x08, 0x7e, 0x10, 0xd8, 0xe3
};
static const u8 pkex_resp_y_bp_p256r1[32] = {
0x2a, 0xfa, 0x98, 0x9b, 0xe3, 0xda, 0x30, 0xfd,
0x32, 0x28, 0xcb, 0x66, 0xfb, 0x40, 0x7f, 0xf2,
0xb2, 0x25, 0x80, 0x82, 0x44, 0x85, 0x13, 0x7e,
0x4b, 0xb5, 0x06, 0xc0, 0x03, 0x69, 0x23, 0x64
};
/* Brainpool P-384r1 */
static const u8 pkex_init_x_bp_p384r1[48] = {
0x0a, 0x2c, 0xeb, 0x49, 0x5e, 0xb7, 0x23, 0xbd,
0x20, 0x5b, 0xe0, 0x49, 0xdf, 0xcf, 0xcf, 0x19,
0x37, 0x36, 0xe1, 0x2f, 0x59, 0xdb, 0x07, 0x06,
0xb5, 0xeb, 0x2d, 0xae, 0xc2, 0xb2, 0x38, 0x62,
0xa6, 0x73, 0x09, 0xa0, 0x6c, 0x0a, 0xa2, 0x30,
0x99, 0xeb, 0xf7, 0x1e, 0x47, 0xb9, 0x5e, 0xbe
};
static const u8 pkex_init_y_bp_p384r1[48] = {
0x54, 0x76, 0x61, 0x65, 0x75, 0x5a, 0x2f, 0x99,
0x39, 0x73, 0xca, 0x6c, 0xf9, 0xf7, 0x12, 0x86,
0x54, 0xd5, 0xd4, 0xad, 0x45, 0x7b, 0xbf, 0x32,
0xee, 0x62, 0x8b, 0x9f, 0x52, 0xe8, 0xa0, 0xc9,
0xb7, 0x9d, 0xd1, 0x09, 0xb4, 0x79, 0x1c, 0x3e,
0x1a, 0xbf, 0x21, 0x45, 0x66, 0x6b, 0x02, 0x52
};
static const u8 pkex_resp_x_bp_p384r1[48] = {
0x03, 0xa2, 0x57, 0xef, 0xe8, 0x51, 0x21, 0xa0,
0xc8, 0x9e, 0x21, 0x02, 0xb5, 0x9a, 0x36, 0x25,
0x74, 0x22, 0xd1, 0xf2, 0x1b, 0xa8, 0x9a, 0x9b,
0x97, 0xbc, 0x5a, 0xeb, 0x26, 0x15, 0x09, 0x71,
0x77, 0x59, 0xec, 0x8b, 0xb7, 0xe1, 0xe8, 0xce,
0x65, 0xb8, 0xaf, 0xf8, 0x80, 0xae, 0x74, 0x6c
};
static const u8 pkex_resp_y_bp_p384r1[48] = {
0x2f, 0xd9, 0x6a, 0xc7, 0x3e, 0xec, 0x76, 0x65,
0x2d, 0x38, 0x7f, 0xec, 0x63, 0x26, 0x3f, 0x04,
0xd8, 0x4e, 0xff, 0xe1, 0x0a, 0x51, 0x74, 0x70,
0xe5, 0x46, 0x63, 0x7f, 0x5c, 0xc0, 0xd1, 0x7c,
0xfb, 0x2f, 0xea, 0xe2, 0xd8, 0x0f, 0x84, 0xcb,
0xe9, 0x39, 0x5c, 0x64, 0xfe, 0xcb, 0x2f, 0xf1
};
/* Brainpool P-512r1 */
static const u8 pkex_init_x_bp_p512r1[64] = {
0x4c, 0xe9, 0xb6, 0x1c, 0xe2, 0x00, 0x3c, 0x9c,
0xa9, 0xc8, 0x56, 0x52, 0xaf, 0x87, 0x3e, 0x51,
0x9c, 0xbb, 0x15, 0x31, 0x1e, 0xc1, 0x05, 0xfc,
0x7c, 0x77, 0xd7, 0x37, 0x61, 0x27, 0xd0, 0x95,
0x98, 0xee, 0x5d, 0xa4, 0x3d, 0x09, 0xdb, 0x3d,
0xfa, 0x89, 0x9e, 0x7f, 0xa6, 0xa6, 0x9c, 0xff,
0x83, 0x5c, 0x21, 0x6c, 0x3e, 0xf2, 0xfe, 0xdc,
0x63, 0xe4, 0xd1, 0x0e, 0x75, 0x45, 0x69, 0x0f
};
static const u8 pkex_init_y_bp_p512r1[64] = {
0x5a, 0x28, 0x01, 0xbe, 0x96, 0x82, 0x4e, 0xf6,
0xfa, 0xed, 0x7d, 0xfd, 0x48, 0x8b, 0x48, 0x4e,
0xd1, 0x97, 0x87, 0xc4, 0x05, 0x5d, 0x15, 0x2a,
0xf4, 0x91, 0x4b, 0x75, 0x90, 0xd9, 0x34, 0x2c,
0x3c, 0x12, 0xf2, 0xf5, 0x25, 0x94, 0x24, 0x34,
0xa7, 0x6d, 0x66, 0xbc, 0x27, 0xa4, 0xa0, 0x8d,
0xd5, 0xe1, 0x54, 0xa3, 0x55, 0x26, 0xd4, 0x14,
0x17, 0x0f, 0xc1, 0xc7, 0x3d, 0x68, 0x7f, 0x5a
};
static const u8 pkex_resp_x_bp_p512r1[64] = {
0x2a, 0x60, 0x32, 0x27, 0xa1, 0xe6, 0x94, 0x72,
0x1c, 0x48, 0xbe, 0xc5, 0x77, 0x14, 0x30, 0x76,
0xe4, 0xbf, 0xf7, 0x7b, 0xc5, 0xfd, 0xdf, 0x19,
0x1e, 0x0f, 0xdf, 0x1c, 0x40, 0xfa, 0x34, 0x9e,
0x1f, 0x42, 0x24, 0xa3, 0x2c, 0xd5, 0xc7, 0xc9,
0x7b, 0x47, 0x78, 0x96, 0xf1, 0x37, 0x0e, 0x88,
0xcb, 0xa6, 0x52, 0x29, 0xd7, 0xa8, 0x38, 0x29,
0x8e, 0x6e, 0x23, 0x47, 0xd4, 0x4b, 0x70, 0x3e
};
static const u8 pkex_resp_y_bp_p512r1[64] = {
0x2a, 0xbe, 0x59, 0xe6, 0xc4, 0xb3, 0xd8, 0x09,
0x66, 0x89, 0x0a, 0x2d, 0x19, 0xf0, 0x9c, 0x9f,
0xb4, 0xab, 0x8f, 0x50, 0x68, 0x3c, 0x74, 0x64,
0x4e, 0x19, 0x55, 0x81, 0x9b, 0x48, 0x5c, 0xf4,
0x12, 0x8d, 0xb9, 0xd8, 0x02, 0x5b, 0xe1, 0x26,
0x7e, 0x19, 0x5c, 0xfd, 0x70, 0xf7, 0x4b, 0xdc,
0xb5, 0x5d, 0xc1, 0x7a, 0xe9, 0xd1, 0x05, 0x2e,
0xd1, 0xfd, 0x2f, 0xce, 0x63, 0x77, 0x48, 0x2c
};
static int dpp_hash_vector(const struct dpp_curve_params *curve,
size_t num_elem, const u8 *addr[], const size_t *len,
u8 *mac)
{
if (curve->hash_len == 32)
return sha256_vector(num_elem, addr, len, mac);
if (curve->hash_len == 48)
return sha384_vector(num_elem, addr, len, mac);
if (curve->hash_len == 64)
return sha512_vector(num_elem, addr, len, mac);
return -1;
}
static int dpp_hkdf_expand(size_t hash_len, const u8 *secret, size_t secret_len,
const char *label, u8 *out, size_t outlen)
{
if (hash_len == 32)
return hmac_sha256_kdf(secret, secret_len, NULL,
(const u8 *) label, os_strlen(label),
out, outlen);
if (hash_len == 48)
return hmac_sha384_kdf(secret, secret_len, NULL,
(const u8 *) label, os_strlen(label),
out, outlen);
if (hash_len == 64)
return hmac_sha512_kdf(secret, secret_len, NULL,
(const u8 *) label, os_strlen(label),
out, outlen);
return -1;
}
static int dpp_hmac_vector(size_t hash_len, const u8 *key, size_t key_len,
size_t num_elem, const u8 *addr[],
const size_t *len, u8 *mac)
{
if (hash_len == 32)
return hmac_sha256_vector(key, key_len, num_elem, addr, len,
mac);
if (hash_len == 48)
return hmac_sha384_vector(key, key_len, num_elem, addr, len,
mac);
if (hash_len == 64)
return hmac_sha512_vector(key, key_len, num_elem, addr, len,
mac);
return -1;
}
static int dpp_hmac(size_t hash_len, const u8 *key, size_t key_len,
const u8 *data, size_t data_len, u8 *mac)
{
if (hash_len == 32)
return hmac_sha256(key, key_len, data, data_len, mac);
if (hash_len == 48)
return hmac_sha384(key, key_len, data, data_len, mac);
if (hash_len == 64)
return hmac_sha512(key, key_len, data, data_len, mac);
return -1;
}
static struct wpabuf * dpp_get_pubkey_point(EVP_PKEY *pkey, int prefix)
{
int len, res;
EC_KEY *eckey;
struct wpabuf *buf;
unsigned char *pos;
eckey = EVP_PKEY_get1_EC_KEY(pkey);
if (!eckey)
return NULL;
EC_KEY_set_conv_form(eckey, POINT_CONVERSION_UNCOMPRESSED);
len = i2o_ECPublicKey(eckey, NULL);
if (len <= 0) {
wpa_printf(MSG_ERROR,
"DDP: Failed to determine public key encoding length");
EC_KEY_free(eckey);
return NULL;
}
buf = wpabuf_alloc(len);
if (!buf) {
EC_KEY_free(eckey);
return NULL;
}
pos = wpabuf_put(buf, len);
res = i2o_ECPublicKey(eckey, &pos);
EC_KEY_free(eckey);
if (res != len) {
wpa_printf(MSG_ERROR,
"DDP: Failed to encode public key (res=%d/%d)",
res, len);
wpabuf_free(buf);
return NULL;
}
if (!prefix) {
/* Remove 0x04 prefix to match DPP definition */
pos = wpabuf_mhead(buf);
os_memmove(pos, pos + 1, len - 1);
buf->used--;
}
return buf;
}
static EVP_PKEY * dpp_set_pubkey_point_group(const EC_GROUP *group,
const u8 *buf_x, const u8 *buf_y,
size_t len)
{
EC_KEY *eckey = NULL;
BN_CTX *ctx;
EC_POINT *point = NULL;
BIGNUM *x = NULL, *y = NULL;
EVP_PKEY *pkey = NULL;
ctx = BN_CTX_new();
if (!ctx) {
wpa_printf(MSG_ERROR, "DPP: Out of memory");
return NULL;
}
point = EC_POINT_new(group);
x = BN_bin2bn(buf_x, len, NULL);
y = BN_bin2bn(buf_y, len, NULL);
if (!point || !x || !y) {
wpa_printf(MSG_ERROR, "DPP: Out of memory");
goto fail;
}
if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) {
wpa_printf(MSG_ERROR,
"DPP: OpenSSL: EC_POINT_set_affine_coordinates_GFp failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
if (!EC_POINT_is_on_curve(group, point, ctx) ||
EC_POINT_is_at_infinity(group, point)) {
wpa_printf(MSG_ERROR, "DPP: Invalid point");
goto fail;
}
eckey = EC_KEY_new();
if (!eckey ||
EC_KEY_set_group(eckey, group) != 1 ||
EC_KEY_set_public_key(eckey, point) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to set EC_KEY: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
EC_KEY_set_asn1_flag(eckey, OPENSSL_EC_NAMED_CURVE);
pkey = EVP_PKEY_new();
if (!pkey || EVP_PKEY_set1_EC_KEY(pkey, eckey) != 1) {
wpa_printf(MSG_ERROR, "DPP: Could not create EVP_PKEY");
goto fail;
}
out:
BN_free(x);
BN_free(y);
EC_KEY_free(eckey);
EC_POINT_free(point);
BN_CTX_free(ctx);
return pkey;
fail:
EVP_PKEY_free(pkey);
pkey = NULL;
goto out;
}
static EVP_PKEY * dpp_set_pubkey_point(EVP_PKEY *group_key,
const u8 *buf, size_t len)
{
EC_KEY *eckey;
const EC_GROUP *group;
EVP_PKEY *pkey = NULL;
if (len & 1)
return NULL;
eckey = EVP_PKEY_get1_EC_KEY(group_key);
if (!eckey) {
wpa_printf(MSG_ERROR,
"DPP: Could not get EC_KEY from group_key");
return NULL;
}
group = EC_KEY_get0_group(eckey);
if (group)
pkey = dpp_set_pubkey_point_group(group, buf, buf + len / 2,
len / 2);
else
wpa_printf(MSG_ERROR, "DPP: Could not get EC group");
EC_KEY_free(eckey);
return pkey;
}
struct wpabuf * dpp_alloc_msg(enum dpp_public_action_frame_type type,
size_t len)
{
struct wpabuf *msg;
msg = wpabuf_alloc(8 + len);
if (!msg)
return NULL;
wpabuf_put_u8(msg, WLAN_ACTION_PUBLIC);
wpabuf_put_u8(msg, WLAN_PA_VENDOR_SPECIFIC);
wpabuf_put_be24(msg, OUI_WFA);
wpabuf_put_u8(msg, DPP_OUI_TYPE);
wpabuf_put_u8(msg, 1); /* Crypto Suite */
wpabuf_put_u8(msg, type);
return msg;
}
const u8 * dpp_get_attr(const u8 *buf, size_t len, u16 req_id, u16 *ret_len)
{
u16 id, alen;
const u8 *pos = buf, *end = buf + len;
while (end - pos >= 4) {
id = WPA_GET_LE16(pos);
pos += 2;
alen = WPA_GET_LE16(pos);
pos += 2;
if (alen > end - pos)
return NULL;
if (id == req_id) {
*ret_len = alen;
return pos;
}
pos += alen;
}
return NULL;
}
int dpp_check_attrs(const u8 *buf, size_t len)
{
const u8 *pos, *end;
pos = buf;
end = buf + len;
while (end - pos >= 4) {
u16 id, alen;
id = WPA_GET_LE16(pos);
pos += 2;
alen = WPA_GET_LE16(pos);
pos += 2;
wpa_printf(MSG_MSGDUMP, "DPP: Attribute ID %04x len %u",
id, alen);
if (alen > end - pos) {
wpa_printf(MSG_DEBUG,
"DPP: Truncated message - not enough room for the attribute - dropped");
return -1;
}
pos += alen;
}
if (end != pos) {
wpa_printf(MSG_DEBUG,
"DPP: Unexpected octets (%d) after the last attribute",
(int) (end - pos));
return -1;
}
return 0;
}
void dpp_bootstrap_info_free(struct dpp_bootstrap_info *info)
{
if (!info)
return;
os_free(info->uri);
os_free(info->info);
EVP_PKEY_free(info->pubkey);
os_free(info);
}
const char * dpp_bootstrap_type_txt(enum dpp_bootstrap_type type)
{
switch (type) {
case DPP_BOOTSTRAP_QR_CODE:
return "QRCODE";
case DPP_BOOTSTRAP_PKEX:
return "PKEX";
}
return "??";
}
static int dpp_uri_valid_info(const char *info)
{
while (*info) {
unsigned char val = *info++;
if (val < 0x20 || val > 0x7e || val == 0x3b)
return 0;
}
return 1;
}
static int dpp_clone_uri(struct dpp_bootstrap_info *bi, const char *uri)
{
bi->uri = os_strdup(uri);
return bi->uri ? 0 : -1;
}
int dpp_parse_uri_chan_list(struct dpp_bootstrap_info *bi,
const char *chan_list)
{
const char *pos = chan_list;
int opclass, channel, freq;
while (pos && *pos && *pos != ';') {
opclass = atoi(pos);
if (opclass <= 0)
goto fail;
pos = os_strchr(pos, '/');
if (!pos)
goto fail;
pos++;
channel = atoi(pos);
if (channel <= 0)
goto fail;
while (*pos >= '0' && *pos <= '9')
pos++;
freq = ieee80211_chan_to_freq(NULL, opclass, channel);
wpa_printf(MSG_DEBUG,
"DPP: URI channel-list: opclass=%d channel=%d ==> freq=%d",
opclass, channel, freq);
if (freq < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Ignore unknown URI channel-list channel (opclass=%d channel=%d)",
opclass, channel);
} else if (bi->num_freq == DPP_BOOTSTRAP_MAX_FREQ) {
wpa_printf(MSG_DEBUG,
"DPP: Too many channels in URI channel-list - ignore list");
bi->num_freq = 0;
break;
} else {
bi->freq[bi->num_freq++] = freq;
}
if (*pos == ';' || *pos == '\0')
break;
if (*pos != ',')
goto fail;
pos++;
}
return 0;
fail:
wpa_printf(MSG_DEBUG, "DPP: Invalid URI channel-list");
return -1;
}
int dpp_parse_uri_mac(struct dpp_bootstrap_info *bi, const char *mac)
{
if (!mac)
return 0;
if (hwaddr_aton2(mac, bi->mac_addr) < 0) {
wpa_printf(MSG_DEBUG, "DPP: Invalid URI mac");
return -1;
}
wpa_printf(MSG_DEBUG, "DPP: URI mac: " MACSTR, MAC2STR(bi->mac_addr));
return 0;
}
int dpp_parse_uri_info(struct dpp_bootstrap_info *bi, const char *info)
{
const char *end;
if (!info)
return 0;
end = os_strchr(info, ';');
if (!end)
end = info + os_strlen(info);
bi->info = os_malloc(end - info + 1);
if (!bi->info)
return -1;
os_memcpy(bi->info, info, end - info);
bi->info[end - info] = '\0';
wpa_printf(MSG_DEBUG, "DPP: URI(information): %s", bi->info);
if (!dpp_uri_valid_info(bi->info)) {
wpa_printf(MSG_DEBUG, "DPP: Invalid URI information payload");
return -1;
}
return 0;
}
static const struct dpp_curve_params *
dpp_get_curve_oid(const ASN1_OBJECT *poid)
{
ASN1_OBJECT *oid;
int i;
for (i = 0; dpp_curves[i].name; i++) {
oid = OBJ_txt2obj(dpp_curves[i].name, 0);
if (oid && OBJ_cmp(poid, oid) == 0)
return &dpp_curves[i];
}
return NULL;
}
static const struct dpp_curve_params * dpp_get_curve_nid(int nid)
{
int i, tmp;
if (!nid)
return NULL;
for (i = 0; dpp_curves[i].name; i++) {
tmp = OBJ_txt2nid(dpp_curves[i].name);
if (tmp == nid)
return &dpp_curves[i];
}
return NULL;
}
static int dpp_parse_uri_pk(struct dpp_bootstrap_info *bi, const char *info)
{
const char *end;
u8 *data;
size_t data_len;
EVP_PKEY *pkey;
const unsigned char *p;
int res;
X509_PUBKEY *pub = NULL;
ASN1_OBJECT *ppkalg;
const unsigned char *pk;
int ppklen;
X509_ALGOR *pa;
#if OPENSSL_VERSION_NUMBER < 0x10100000L
ASN1_OBJECT *pa_oid;
#else
const ASN1_OBJECT *pa_oid;
#endif
const void *pval;
int ptype;
const ASN1_OBJECT *poid;
char buf[100];
end = os_strchr(info, ';');
if (!end)
return -1;
data = base64_decode((const unsigned char *) info, end - info,
&data_len);
if (!data) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid base64 encoding on URI public-key");
return -1;
}
wpa_hexdump(MSG_DEBUG, "DPP: Base64 decoded URI public-key",
data, data_len);
if (sha256_vector(1, (const u8 **) &data, &data_len,
bi->pubkey_hash) < 0) {
wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key");
return -1;
}
wpa_hexdump(MSG_DEBUG, "DPP: Public key hash",
bi->pubkey_hash, SHA256_MAC_LEN);
/* DER encoded ASN.1 SubjectPublicKeyInfo
*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING }
*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL }
*
* subjectPublicKey = compressed format public key per ANSI X9.63
* algorithm = ecPublicKey (1.2.840.10045.2.1)
* parameters = shall be present and shall be OBJECT IDENTIFIER; e.g.,
* prime256v1 (1.2.840.10045.3.1.7)
*/
p = data;
pkey = d2i_PUBKEY(NULL, &p, data_len);
os_free(data);
if (!pkey) {
wpa_printf(MSG_DEBUG,
"DPP: Could not parse URI public-key SubjectPublicKeyInfo");
return -1;
}
if (EVP_PKEY_type(EVP_PKEY_id(pkey)) != EVP_PKEY_EC) {
wpa_printf(MSG_DEBUG,
"DPP: SubjectPublicKeyInfo does not describe an EC key");
EVP_PKEY_free(pkey);
return -1;
}
res = X509_PUBKEY_set(&pub, pkey);
if (res != 1) {
wpa_printf(MSG_DEBUG, "DPP: Could not set pubkey");
goto fail;
}
res = X509_PUBKEY_get0_param(&ppkalg, &pk, &ppklen, &pa, pub);
if (res != 1) {
wpa_printf(MSG_DEBUG,
"DPP: Could not extract SubjectPublicKeyInfo parameters");
goto fail;
}
res = OBJ_obj2txt(buf, sizeof(buf), ppkalg, 0);
if (res < 0 || (size_t) res >= sizeof(buf)) {
wpa_printf(MSG_DEBUG,
"DPP: Could not extract SubjectPublicKeyInfo algorithm");
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: URI subjectPublicKey algorithm: %s", buf);
if (os_strcmp(buf, "id-ecPublicKey") != 0) {
wpa_printf(MSG_DEBUG,
"DPP: Unsupported SubjectPublicKeyInfo algorithm");
goto fail;
}
X509_ALGOR_get0(&pa_oid, &ptype, (void *) &pval, pa);
if (ptype != V_ASN1_OBJECT) {
wpa_printf(MSG_DEBUG,
"DPP: SubjectPublicKeyInfo parameters did not contain an OID");
goto fail;
}
poid = pval;
res = OBJ_obj2txt(buf, sizeof(buf), poid, 0);
if (res < 0 || (size_t) res >= sizeof(buf)) {
wpa_printf(MSG_DEBUG,
"DPP: Could not extract SubjectPublicKeyInfo parameters OID");
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: URI subjectPublicKey parameters: %s", buf);
bi->curve = dpp_get_curve_oid(poid);
if (!bi->curve) {
wpa_printf(MSG_DEBUG,
"DPP: Unsupported SubjectPublicKeyInfo curve: %s",
buf);
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: URI subjectPublicKey", pk, ppklen);
X509_PUBKEY_free(pub);
bi->pubkey = pkey;
return 0;
fail:
X509_PUBKEY_free(pub);
EVP_PKEY_free(pkey);
return -1;
}
static struct dpp_bootstrap_info * dpp_parse_uri(const char *uri)
{
const char *pos = uri;
const char *end;
const char *chan_list = NULL, *mac = NULL, *info = NULL, *pk = NULL;
struct dpp_bootstrap_info *bi;
wpa_hexdump_ascii(MSG_DEBUG, "DPP: URI", uri, os_strlen(uri));
if (os_strncmp(pos, "DPP:", 4) != 0) {
wpa_printf(MSG_INFO, "DPP: Not a DPP URI");
return NULL;
}
pos += 4;
for (;;) {
end = os_strchr(pos, ';');
if (!end)
break;
if (end == pos) {
/* Handle terminating ";;" and ignore unexpected ";"
* for parsing robustness. */
pos++;
continue;
}
if (pos[0] == 'C' && pos[1] == ':' && !chan_list)
chan_list = pos + 2;
else if (pos[0] == 'M' && pos[1] == ':' && !mac)
mac = pos + 2;
else if (pos[0] == 'I' && pos[1] == ':' && !info)
info = pos + 2;
else if (pos[0] == 'K' && pos[1] == ':' && !pk)
pk = pos + 2;
else
wpa_hexdump_ascii(MSG_DEBUG,
"DPP: Ignore unrecognized URI parameter",
pos, end - pos);
pos = end + 1;
}
if (!pk) {
wpa_printf(MSG_INFO, "DPP: URI missing public-key");
return NULL;
}
bi = os_zalloc(sizeof(*bi));
if (!bi)
return NULL;
if (dpp_clone_uri(bi, uri) < 0 ||
dpp_parse_uri_chan_list(bi, chan_list) < 0 ||
dpp_parse_uri_mac(bi, mac) < 0 ||
dpp_parse_uri_info(bi, info) < 0 ||
dpp_parse_uri_pk(bi, pk) < 0) {
dpp_bootstrap_info_free(bi);
bi = NULL;
}
return bi;
}
struct dpp_bootstrap_info * dpp_parse_qr_code(const char *uri)
{
struct dpp_bootstrap_info *bi;
bi = dpp_parse_uri(uri);
if (bi)
bi->type = DPP_BOOTSTRAP_QR_CODE;
return bi;
}
static void dpp_debug_print_key(const char *title, EVP_PKEY *key)
{
EC_KEY *eckey;
BIO *out;
size_t rlen;
char *txt;
int res;
unsigned char *der = NULL;
int der_len;
out = BIO_new(BIO_s_mem());
if (!out)
return;
EVP_PKEY_print_private(out, key, 0, NULL);
rlen = BIO_ctrl_pending(out);
txt = os_malloc(rlen + 1);
if (txt) {
res = BIO_read(out, txt, rlen);
if (res > 0) {
txt[res] = '\0';
wpa_printf(MSG_DEBUG, "%s: %s", title, txt);
}
os_free(txt);
}
BIO_free(out);
eckey = EVP_PKEY_get1_EC_KEY(key);
if (!eckey)
return;
der_len = i2d_ECPrivateKey(eckey, &der);
if (der_len > 0)
wpa_hexdump_key(MSG_DEBUG, "DPP: ECPrivateKey", der, der_len);
OPENSSL_free(der);
if (der_len <= 0) {
der = NULL;
der_len = i2d_EC_PUBKEY(eckey, &der);
if (der_len > 0)
wpa_hexdump(MSG_DEBUG, "DPP: EC_PUBKEY", der, der_len);
OPENSSL_free(der);
}
EC_KEY_free(eckey);
}
static EVP_PKEY * dpp_gen_keypair(const struct dpp_curve_params *curve)
{
#ifdef OPENSSL_IS_BORINGSSL
EVP_PKEY_CTX *kctx = NULL;
const EC_GROUP *group;
EC_KEY *ec_params;
#else
EVP_PKEY_CTX *pctx, *kctx = NULL;
#endif
EVP_PKEY *params = NULL, *key = NULL;
int nid;
wpa_printf(MSG_DEBUG, "DPP: Generating a keypair");
nid = OBJ_txt2nid(curve->name);
if (nid == NID_undef) {
wpa_printf(MSG_INFO, "DPP: Unsupported curve %s", curve->name);
return NULL;
}
#ifdef OPENSSL_IS_BORINGSSL
group = EC_GROUP_new_by_curve_name(nid);
ec_params = EC_KEY_new();
if (!ec_params || EC_KEY_set_group(ec_params, group) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to generate EC_KEY parameters");
goto fail;
}
EC_KEY_set_asn1_flag(ec_params, OPENSSL_EC_NAMED_CURVE);
params = EVP_PKEY_new();
if (!params || EVP_PKEY_set1_EC_KEY(params, ec_params) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to generate EVP_PKEY parameters");
goto fail;
}
#else
pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL);
if (!pctx ||
EVP_PKEY_paramgen_init(pctx) != 1 ||
EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx, nid) != 1 ||
EVP_PKEY_CTX_set_ec_param_enc(pctx, OPENSSL_EC_NAMED_CURVE) != 1 ||
EVP_PKEY_paramgen(pctx, ¶ms) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to generate EVP_PKEY parameters");
EVP_PKEY_CTX_free(pctx);
goto fail;
}
EVP_PKEY_CTX_free(pctx);
#endif
kctx = EVP_PKEY_CTX_new(params, NULL);
if (!kctx ||
EVP_PKEY_keygen_init(kctx) != 1 ||
EVP_PKEY_keygen(kctx, &key) != 1) {
wpa_printf(MSG_ERROR, "DPP: Failed to generate EC key");
goto fail;
}
if (wpa_debug_show_keys)
dpp_debug_print_key("Own generated key", key);
EVP_PKEY_free(params);
EVP_PKEY_CTX_free(kctx);
return key;
fail:
EVP_PKEY_CTX_free(kctx);
EVP_PKEY_free(params);
return NULL;
}
static const struct dpp_curve_params *
dpp_get_curve_name(const char *name)
{
int i;
for (i = 0; dpp_curves[i].name; i++) {
if (os_strcmp(name, dpp_curves[i].name) == 0 ||
(dpp_curves[i].jwk_crv &&
os_strcmp(name, dpp_curves[i].jwk_crv) == 0))
return &dpp_curves[i];
}
return NULL;
}
static const struct dpp_curve_params *
dpp_get_curve_jwk_crv(const char *name)
{
int i;
for (i = 0; dpp_curves[i].name; i++) {
if (dpp_curves[i].jwk_crv &&
os_strcmp(name, dpp_curves[i].jwk_crv) == 0)
return &dpp_curves[i];
}
return NULL;
}
static EVP_PKEY * dpp_set_keypair(const struct dpp_curve_params **curve,
const u8 *privkey, size_t privkey_len)
{
EVP_PKEY *pkey;
EC_KEY *eckey;
const EC_GROUP *group;
int nid;
pkey = EVP_PKEY_new();
if (!pkey)
return NULL;
eckey = d2i_ECPrivateKey(NULL, &privkey, privkey_len);
if (!eckey) {
wpa_printf(MSG_INFO,
"DPP: OpenSSL: d2i_ECPrivateKey() failed: %s",
ERR_error_string(ERR_get_error(), NULL));
EVP_PKEY_free(pkey);
return NULL;
}
group = EC_KEY_get0_group(eckey);
if (!group) {
EC_KEY_free(eckey);
EVP_PKEY_free(pkey);
return NULL;
}
nid = EC_GROUP_get_curve_name(group);
*curve = dpp_get_curve_nid(nid);
if (!*curve) {
wpa_printf(MSG_INFO,
"DPP: Unsupported curve (nid=%d) in pre-assigned key",
nid);
EC_KEY_free(eckey);
EVP_PKEY_free(pkey);
return NULL;
}
if (EVP_PKEY_assign_EC_KEY(pkey, eckey) != 1) {
EC_KEY_free(eckey);
EVP_PKEY_free(pkey);
return NULL;
}
return pkey;
}
int dpp_bootstrap_key_hash(struct dpp_bootstrap_info *bi)
{
unsigned char *der = NULL;
int der_len;
EC_KEY *eckey;
int res;
size_t len;
/* Need to get the compressed form of the public key through EC_KEY, so
* cannot use the simpler i2d_PUBKEY() here. */
eckey = EVP_PKEY_get1_EC_KEY(bi->pubkey);
if (!eckey)
return -1;
EC_KEY_set_conv_form(eckey, POINT_CONVERSION_COMPRESSED);
der_len = i2d_EC_PUBKEY(eckey, &der);
EC_KEY_free(eckey);
if (der_len <= 0) {
wpa_printf(MSG_ERROR,
"DDP: Failed to build DER encoded public key");
OPENSSL_free(der);
return -1;
}
len = der_len;
res = sha256_vector(1, (const u8 **) &der, &len, bi->pubkey_hash);
OPENSSL_free(der);
if (res < 0)
wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key");
return res;
}
char * dpp_keygen(struct dpp_bootstrap_info *bi, const char *curve,
const u8 *privkey, size_t privkey_len)
{
unsigned char *base64 = NULL;
char *pos, *end;
size_t len;
unsigned char *der = NULL;
int der_len;
EC_KEY *eckey;
if (!curve) {
bi->curve = &dpp_curves[0];
} else {
bi->curve = dpp_get_curve_name(curve);
if (!bi->curve) {
wpa_printf(MSG_INFO, "DPP: Unsupported curve: %s",
curve);
return NULL;
}
}
if (privkey)
bi->pubkey = dpp_set_keypair(&bi->curve, privkey, privkey_len);
else
bi->pubkey = dpp_gen_keypair(bi->curve);
if (!bi->pubkey)
goto fail;
bi->own = 1;
/* Need to get the compressed form of the public key through EC_KEY, so
* cannot use the simpler i2d_PUBKEY() here. */
eckey = EVP_PKEY_get1_EC_KEY(bi->pubkey);
if (!eckey)
goto fail;
EC_KEY_set_conv_form(eckey, POINT_CONVERSION_COMPRESSED);
der_len = i2d_EC_PUBKEY(eckey, &der);
EC_KEY_free(eckey);
if (der_len <= 0) {
wpa_printf(MSG_ERROR,
"DDP: Failed to build DER encoded public key");
goto fail;
}
len = der_len;
if (sha256_vector(1, (const u8 **) &der, &len, bi->pubkey_hash) < 0) {
wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key");
goto fail;
}
base64 = base64_encode(der, der_len, &len);
OPENSSL_free(der);
der = NULL;
if (!base64)
goto fail;
pos = (char *) base64;
end = pos + len;
for (;;) {
pos = os_strchr(pos, '\n');
if (!pos)
break;
os_memmove(pos, pos + 1, end - pos);
}
return (char *) base64;
fail:
os_free(base64);
OPENSSL_free(der);
return NULL;
}
static int dpp_derive_k1(const u8 *Mx, size_t Mx_len, u8 *k1,
unsigned int hash_len)
{
u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN];
const char *info = "first intermediate key";
int res;
/* k1 = HKDF(<>, "first intermediate key", M.x) */
/* HKDF-Extract(<>, M.x) */
os_memset(salt, 0, hash_len);
if (dpp_hmac(hash_len, salt, hash_len, Mx, Mx_len, prk) < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM=M.x)",
prk, hash_len);
/* HKDF-Expand(PRK, info, L) */
res = dpp_hkdf_expand(hash_len, prk, hash_len, info, k1, hash_len);
os_memset(prk, 0, hash_len);
if (res < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: k1 = HKDF-Expand(PRK, info, L)",
k1, hash_len);
return 0;
}
static int dpp_derive_k2(const u8 *Nx, size_t Nx_len, u8 *k2,
unsigned int hash_len)
{
u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN];
const char *info = "second intermediate key";
int res;
/* k2 = HKDF(<>, "second intermediate key", N.x) */
/* HKDF-Extract(<>, N.x) */
os_memset(salt, 0, hash_len);
res = dpp_hmac(hash_len, salt, hash_len, Nx, Nx_len, prk);
if (res < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM=N.x)",
prk, hash_len);
/* HKDF-Expand(PRK, info, L) */
res = dpp_hkdf_expand(hash_len, prk, hash_len, info, k2, hash_len);
os_memset(prk, 0, hash_len);
if (res < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: k2 = HKDF-Expand(PRK, info, L)",
k2, hash_len);
return 0;
}
static int dpp_derive_ke(struct dpp_authentication *auth, u8 *ke,
unsigned int hash_len)
{
size_t nonce_len;
u8 nonces[2 * DPP_MAX_NONCE_LEN];
const char *info_ke = "DPP Key";
u8 prk[DPP_MAX_HASH_LEN];
int res;
const u8 *addr[3];
size_t len[3];
size_t num_elem = 0;
/* ke = HKDF(I-nonce | R-nonce, "DPP Key", M.x | N.x [| L.x]) */
/* HKDF-Extract(I-nonce | R-nonce, M.x | N.x [| L.x]) */
nonce_len = auth->curve->nonce_len;
os_memcpy(nonces, auth->i_nonce, nonce_len);
os_memcpy(&nonces[nonce_len], auth->r_nonce, nonce_len);
addr[num_elem] = auth->Mx;
len[num_elem] = auth->secret_len;
num_elem++;
addr[num_elem] = auth->Nx;
len[num_elem] = auth->secret_len;
num_elem++;
if (auth->peer_bi && auth->own_bi) {
addr[num_elem] = auth->Lx;
len[num_elem] = auth->secret_len;
num_elem++;
}
res = dpp_hmac_vector(hash_len, nonces, 2 * nonce_len,
num_elem, addr, len, prk);
if (res < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM)",
prk, hash_len);
/* HKDF-Expand(PRK, info, L) */
res = dpp_hkdf_expand(hash_len, prk, hash_len, info_ke, ke, hash_len);
os_memset(prk, 0, hash_len);
if (res < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: ke = HKDF-Expand(PRK, info, L)",
ke, hash_len);
return 0;
}
struct dpp_authentication * dpp_auth_init(void *msg_ctx,
struct dpp_bootstrap_info *peer_bi,
struct dpp_bootstrap_info *own_bi,
int configurator)
{
struct dpp_authentication *auth;
size_t nonce_len;
EVP_PKEY_CTX *ctx = NULL;
size_t secret_len;
struct wpabuf *msg, *pi = NULL;
u8 clear[4 + DPP_MAX_NONCE_LEN + 4 + 1];
u8 wrapped_data[4 + DPP_MAX_NONCE_LEN + 4 + 1 + AES_BLOCK_SIZE];
u8 *pos;
const u8 *addr[2];
size_t len[2], siv_len, attr_len;
u8 *attr_start, *attr_end;
auth = os_zalloc(sizeof(*auth));
if (!auth)
return NULL;
auth->msg_ctx = msg_ctx;
auth->initiator = 1;
auth->configurator = configurator;
auth->peer_bi = peer_bi;
auth->own_bi = own_bi;
auth->curve = peer_bi->curve;
nonce_len = auth->curve->nonce_len;
if (random_get_bytes(auth->i_nonce, nonce_len)) {
wpa_printf(MSG_ERROR, "DPP: Failed to generate I-nonce");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: I-nonce", auth->i_nonce, nonce_len);
auth->own_protocol_key = dpp_gen_keypair(auth->curve);
if (!auth->own_protocol_key)
goto fail;
pi = dpp_get_pubkey_point(auth->own_protocol_key, 0);
if (!pi)
goto fail;
/* ECDH: M = pI * BR */
ctx = EVP_PKEY_CTX_new(auth->own_protocol_key, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, auth->peer_bi->pubkey) != 1 ||
EVP_PKEY_derive(ctx, NULL, &secret_len) != 1 ||
secret_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, auth->Mx, &secret_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
auth->secret_len = secret_len;
EVP_PKEY_CTX_free(ctx);
ctx = NULL;
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (M.x)",
auth->Mx, auth->secret_len);
if (dpp_derive_k1(auth->Mx, auth->secret_len, auth->k1,
auth->curve->hash_len) < 0)
goto fail;
/* Build DPP Authentication Request frame attributes */
attr_len = 2 * (4 + SHA256_MAC_LEN) + 4 + wpabuf_len(pi) +
4 + sizeof(wrapped_data);
msg = dpp_alloc_msg(DPP_PA_AUTHENTICATION_REQ, attr_len);
if (!msg)
goto fail;
auth->req_msg = msg;
attr_start = wpabuf_put(msg, 0);
/* Responder Bootstrapping Key Hash */
wpabuf_put_le16(msg, DPP_ATTR_R_BOOTSTRAP_KEY_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, auth->peer_bi->pubkey_hash, SHA256_MAC_LEN);
/* Initiator Bootstrapping Key Hash */
wpabuf_put_le16(msg, DPP_ATTR_I_BOOTSTRAP_KEY_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
if (auth->own_bi)
wpabuf_put_data(msg, auth->own_bi->pubkey_hash, SHA256_MAC_LEN);
else
os_memset(wpabuf_put(msg, SHA256_MAC_LEN), 0, SHA256_MAC_LEN);
/* Initiator Protocol Key */
wpabuf_put_le16(msg, DPP_ATTR_I_PROTOCOL_KEY);
wpabuf_put_le16(msg, wpabuf_len(pi));
wpabuf_put_buf(msg, pi);
wpabuf_free(pi);
pi = NULL;
/* Wrapped data ({I-nonce, I-capabilities}k1) */
pos = clear;
/* I-nonce */
WPA_PUT_LE16(pos, DPP_ATTR_I_NONCE);
pos += 2;
WPA_PUT_LE16(pos, nonce_len);
pos += 2;
os_memcpy(pos, auth->i_nonce, nonce_len);
pos += nonce_len;
/* I-capabilities */
WPA_PUT_LE16(pos, DPP_ATTR_I_CAPABILITIES);
pos += 2;
WPA_PUT_LE16(pos, 1);
pos += 2;
auth->i_capab = configurator ? DPP_CAPAB_CONFIGURATOR :
DPP_CAPAB_ENROLLEE;
*pos++ = auth->i_capab;
attr_end = wpabuf_put(msg, 0);
/* OUI, OUI type, Crypto Suite, DPP frame type */
addr[0] = wpabuf_head_u8(msg) + 2;
len[0] = 3 + 1 + 1 + 1;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
/* Attributes before Wrapped Data */
addr[1] = attr_start;
len[1] = attr_end - attr_start;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
siv_len = pos - clear;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext", clear, siv_len);
if (aes_siv_encrypt(auth->k1, auth->curve->hash_len, clear, siv_len,
2, addr, len, wrapped_data) < 0)
goto fail;
siv_len += AES_BLOCK_SIZE;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, siv_len);
wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
wpabuf_put_le16(msg, siv_len);
wpabuf_put_data(msg, wrapped_data, siv_len);
wpa_hexdump_buf(MSG_DEBUG,
"DPP: Authentication Request frame attributes", msg);
return auth;
fail:
wpabuf_free(pi);
EVP_PKEY_CTX_free(ctx);
dpp_auth_deinit(auth);
return NULL;
}
struct wpabuf * dpp_build_conf_req(struct dpp_authentication *auth,
const char *json)
{
size_t nonce_len;
size_t json_len, clear_len;
struct wpabuf *clear = NULL, *msg = NULL;
u8 *wrapped;
wpa_printf(MSG_DEBUG, "DPP: Build configuration request");
nonce_len = auth->curve->nonce_len;
if (random_get_bytes(auth->e_nonce, nonce_len)) {
wpa_printf(MSG_ERROR, "DPP: Failed to generate E-nonce");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: E-nonce", auth->e_nonce, nonce_len);
json_len = os_strlen(json);
wpa_hexdump_ascii(MSG_DEBUG, "DPP: configAttr JSON", json, json_len);
/* { E-nonce, configAttrib }ke */
clear_len = 4 + nonce_len + 4 + json_len;
clear = wpabuf_alloc(clear_len);
msg = wpabuf_alloc(4 + clear_len + AES_BLOCK_SIZE);
if (!clear || !msg)
goto fail;
/* E-nonce */
wpabuf_put_le16(clear, DPP_ATTR_ENROLLEE_NONCE);
wpabuf_put_le16(clear, nonce_len);
wpabuf_put_data(clear, auth->e_nonce, nonce_len);
/* configAttrib */
wpabuf_put_le16(clear, DPP_ATTR_CONFIG_ATTR_OBJ);
wpabuf_put_le16(clear, json_len);
wpabuf_put_data(clear, json, json_len);
wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
wpabuf_put_le16(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
wrapped = wpabuf_put(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
/* No AES-SIV AD */
wpa_hexdump_buf(MSG_DEBUG, "DPP: AES-SIV cleartext", clear);
if (aes_siv_encrypt(auth->ke, auth->curve->hash_len,
wpabuf_head(clear), wpabuf_len(clear),
0, NULL, NULL, wrapped) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped, wpabuf_len(clear) + AES_BLOCK_SIZE);
wpa_hexdump_buf(MSG_DEBUG,
"DPP: Configuration Request frame attributes", msg);
wpabuf_free(clear);
return msg;
fail:
wpabuf_free(clear);
wpabuf_free(msg);
return NULL;
}
static void dpp_auth_success(struct dpp_authentication *auth)
{
wpa_printf(MSG_DEBUG,
"DPP: Authentication success - clear temporary keys");
os_memset(auth->Mx, 0, sizeof(auth->Mx));
os_memset(auth->Nx, 0, sizeof(auth->Nx));
os_memset(auth->Lx, 0, sizeof(auth->Lx));
os_memset(auth->k1, 0, sizeof(auth->k1));
os_memset(auth->k2, 0, sizeof(auth->k2));
auth->auth_success = 1;
}
static int dpp_gen_r_auth(struct dpp_authentication *auth, u8 *r_auth)
{
struct wpabuf *pix, *prx, *bix, *brx;
const u8 *addr[7];
size_t len[7];
size_t i, num_elem = 0;
size_t nonce_len;
u8 zero = 0;
int res = -1;
/* R-auth = H(I-nonce | R-nonce | PI.x | PR.x | [BI.x |] BR.x | 0) */
nonce_len = auth->curve->nonce_len;
if (auth->initiator) {
pix = dpp_get_pubkey_point(auth->own_protocol_key, 0);
prx = dpp_get_pubkey_point(auth->peer_protocol_key, 0);
if (auth->own_bi)
bix = dpp_get_pubkey_point(auth->own_bi->pubkey, 0);
else
bix = NULL;
brx = dpp_get_pubkey_point(auth->peer_bi->pubkey, 0);
} else {
pix = dpp_get_pubkey_point(auth->peer_protocol_key, 0);
prx = dpp_get_pubkey_point(auth->own_protocol_key, 0);
if (auth->peer_bi)
bix = dpp_get_pubkey_point(auth->peer_bi->pubkey, 0);
else
bix = NULL;
brx = dpp_get_pubkey_point(auth->own_bi->pubkey, 0);
}
if (!pix || !prx || !brx)
goto fail;
addr[num_elem] = auth->i_nonce;
len[num_elem] = nonce_len;
num_elem++;
addr[num_elem] = auth->r_nonce;
len[num_elem] = nonce_len;
num_elem++;
addr[num_elem] = wpabuf_head(pix);
len[num_elem] = wpabuf_len(pix) / 2;
num_elem++;
addr[num_elem] = wpabuf_head(prx);
len[num_elem] = wpabuf_len(prx) / 2;
num_elem++;
if (bix) {
addr[num_elem] = wpabuf_head(bix);
len[num_elem] = wpabuf_len(bix) / 2;
num_elem++;
}
addr[num_elem] = wpabuf_head(brx);
len[num_elem] = wpabuf_len(brx) / 2;
num_elem++;
addr[num_elem] = &zero;
len[num_elem] = 1;
num_elem++;
wpa_printf(MSG_DEBUG, "DPP: R-auth hash components");
for (i = 0; i < num_elem; i++)
wpa_hexdump(MSG_DEBUG, "DPP: hash component", addr[i], len[i]);
res = dpp_hash_vector(auth->curve, num_elem, addr, len, r_auth);
if (res == 0)
wpa_hexdump(MSG_DEBUG, "DPP: R-auth", r_auth,
auth->curve->hash_len);
fail:
wpabuf_free(pix);
wpabuf_free(prx);
wpabuf_free(bix);
wpabuf_free(brx);
return res;
}
static int dpp_gen_i_auth(struct dpp_authentication *auth, u8 *i_auth)
{
struct wpabuf *pix = NULL, *prx = NULL, *bix = NULL, *brx = NULL;
const u8 *addr[7];
size_t len[7];
size_t i, num_elem = 0;
size_t nonce_len;
u8 one = 1;
int res = -1;
/* I-auth = H(R-nonce | I-nonce | PR.x | PI.x | BR.x | [BI.x |] 1) */
nonce_len = auth->curve->nonce_len;
if (auth->initiator) {
pix = dpp_get_pubkey_point(auth->own_protocol_key, 0);
prx = dpp_get_pubkey_point(auth->peer_protocol_key, 0);
if (auth->own_bi)
bix = dpp_get_pubkey_point(auth->own_bi->pubkey, 0);
else
bix = NULL;
if (!auth->peer_bi)
goto fail;
brx = dpp_get_pubkey_point(auth->peer_bi->pubkey, 0);
} else {
pix = dpp_get_pubkey_point(auth->peer_protocol_key, 0);
prx = dpp_get_pubkey_point(auth->own_protocol_key, 0);
if (auth->peer_bi)
bix = dpp_get_pubkey_point(auth->peer_bi->pubkey, 0);
else
bix = NULL;
if (!auth->own_bi)
goto fail;
brx = dpp_get_pubkey_point(auth->own_bi->pubkey, 0);
}
if (!pix || !prx || !brx)
goto fail;
addr[num_elem] = auth->r_nonce;
len[num_elem] = nonce_len;
num_elem++;
addr[num_elem] = auth->i_nonce;
len[num_elem] = nonce_len;
num_elem++;
addr[num_elem] = wpabuf_head(prx);
len[num_elem] = wpabuf_len(prx) / 2;
num_elem++;
addr[num_elem] = wpabuf_head(pix);
len[num_elem] = wpabuf_len(pix) / 2;
num_elem++;
addr[num_elem] = wpabuf_head(brx);
len[num_elem] = wpabuf_len(brx) / 2;
num_elem++;
if (bix) {
addr[num_elem] = wpabuf_head(bix);
len[num_elem] = wpabuf_len(bix) / 2;
num_elem++;
}
addr[num_elem] = &one;
len[num_elem] = 1;
num_elem++;
wpa_printf(MSG_DEBUG, "DPP: I-auth hash components");
for (i = 0; i < num_elem; i++)
wpa_hexdump(MSG_DEBUG, "DPP: hash component", addr[i], len[i]);
res = dpp_hash_vector(auth->curve, num_elem, addr, len, i_auth);
if (res == 0)
wpa_hexdump(MSG_DEBUG, "DPP: I-auth", i_auth,
auth->curve->hash_len);
fail:
wpabuf_free(pix);
wpabuf_free(prx);
wpabuf_free(bix);
wpabuf_free(brx);
return res;
}
static int dpp_auth_derive_l_responder(struct dpp_authentication *auth)
{
const EC_GROUP *group;
EC_POINT *l = NULL;
EC_KEY *BI = NULL, *bR = NULL, *pR = NULL;
const EC_POINT *BI_point;
BN_CTX *bnctx;
BIGNUM *lx, *sum, *q;
const BIGNUM *bR_bn, *pR_bn;
int ret = -1;
int num_bytes, offset;
/* L = ((bR + pR) modulo q) * BI */
bnctx = BN_CTX_new();
sum = BN_new();
q = BN_new();
lx = BN_new();
if (!bnctx || !sum || !q || !lx)
goto fail;
BI = EVP_PKEY_get1_EC_KEY(auth->peer_bi->pubkey);
if (!BI)
goto fail;
BI_point = EC_KEY_get0_public_key(BI);
group = EC_KEY_get0_group(BI);
if (!group)
goto fail;
bR = EVP_PKEY_get1_EC_KEY(auth->own_bi->pubkey);
pR = EVP_PKEY_get1_EC_KEY(auth->own_protocol_key);
if (!bR || !pR)
goto fail;
bR_bn = EC_KEY_get0_private_key(bR);
pR_bn = EC_KEY_get0_private_key(pR);
if (!bR_bn || !pR_bn)
goto fail;
if (EC_GROUP_get_order(group, q, bnctx) != 1 ||
BN_mod_add(sum, bR_bn, pR_bn, q, bnctx) != 1)
goto fail;
l = EC_POINT_new(group);
if (!l ||
EC_POINT_mul(group, l, NULL, BI_point, sum, bnctx) != 1 ||
EC_POINT_get_affine_coordinates_GFp(group, l, lx, NULL,
bnctx) != 1) {
wpa_printf(MSG_ERROR,
"OpenSSL: failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
num_bytes = BN_num_bytes(lx);
if ((size_t) num_bytes > auth->secret_len)
goto fail;
if (auth->secret_len > (size_t) num_bytes)
offset = auth->secret_len - num_bytes;
else
offset = 0;
os_memset(auth->Lx, 0, offset);
BN_bn2bin(lx, auth->Lx + offset);
wpa_hexdump_key(MSG_DEBUG, "DPP: L.x", auth->Lx, auth->secret_len);
ret = 0;
fail:
EC_POINT_clear_free(l);
EC_KEY_free(BI);
EC_KEY_free(bR);
EC_KEY_free(pR);
BN_clear_free(lx);
BN_clear_free(sum);
BN_free(q);
BN_CTX_free(bnctx);
return ret;
}
static int dpp_auth_derive_l_initiator(struct dpp_authentication *auth)
{
const EC_GROUP *group;
EC_POINT *l = NULL, *sum = NULL;
EC_KEY *bI = NULL, *BR = NULL, *PR = NULL;
const EC_POINT *BR_point, *PR_point;
BN_CTX *bnctx;
BIGNUM *lx;
const BIGNUM *bI_bn;
int ret = -1;
int num_bytes, offset;
/* L = bI * (BR + PR) */
bnctx = BN_CTX_new();
lx = BN_new();
if (!bnctx || !lx)
goto fail;
BR = EVP_PKEY_get1_EC_KEY(auth->peer_bi->pubkey);
PR = EVP_PKEY_get1_EC_KEY(auth->peer_protocol_key);
if (!BR || !PR)
goto fail;
BR_point = EC_KEY_get0_public_key(BR);
PR_point = EC_KEY_get0_public_key(PR);
bI = EVP_PKEY_get1_EC_KEY(auth->own_bi->pubkey);
if (!bI)
goto fail;
group = EC_KEY_get0_group(bI);
bI_bn = EC_KEY_get0_private_key(bI);
if (!group || !bI_bn)
goto fail;
sum = EC_POINT_new(group);
l = EC_POINT_new(group);
if (!sum || !l ||
EC_POINT_add(group, sum, BR_point, PR_point, bnctx) != 1 ||
EC_POINT_mul(group, l, NULL, sum, bI_bn, bnctx) != 1 ||
EC_POINT_get_affine_coordinates_GFp(group, l, lx, NULL,
bnctx) != 1) {
wpa_printf(MSG_ERROR,
"OpenSSL: failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
num_bytes = BN_num_bytes(lx);
if ((size_t) num_bytes > auth->secret_len)
goto fail;
if (auth->secret_len > (size_t) num_bytes)
offset = auth->secret_len - num_bytes;
else
offset = 0;
os_memset(auth->Lx, 0, offset);
BN_bn2bin(lx, auth->Lx + offset);
wpa_hexdump_key(MSG_DEBUG, "DPP: L.x", auth->Lx, auth->secret_len);
ret = 0;
fail:
EC_POINT_clear_free(l);
EC_KEY_free(bI);
EC_KEY_free(BR);
EC_KEY_free(PR);
BN_clear_free(lx);
BN_CTX_free(bnctx);
return ret;
}
static int dpp_auth_build_resp(struct dpp_authentication *auth)
{
size_t nonce_len;
EVP_PKEY_CTX *ctx = NULL;
size_t secret_len;
struct wpabuf *msg, *pr = NULL;
u8 r_auth[4 + DPP_MAX_HASH_LEN];
u8 wrapped_r_auth[4 + DPP_MAX_HASH_LEN + AES_BLOCK_SIZE];
#define DPP_AUTH_RESP_CLEAR_LEN 2 * (4 + DPP_MAX_NONCE_LEN) + 4 + 1 + \
4 + sizeof(wrapped_r_auth)
size_t wrapped_r_auth_len;
u8 clear[DPP_AUTH_RESP_CLEAR_LEN];
u8 wrapped_data[DPP_AUTH_RESP_CLEAR_LEN + AES_BLOCK_SIZE];
u8 *pos;
const u8 *addr[2];
size_t len[2], siv_len, attr_len;
u8 *attr_start, *attr_end;
wpa_printf(MSG_DEBUG, "DPP: Build Authentication Response");
nonce_len = auth->curve->nonce_len;
if (random_get_bytes(auth->r_nonce, nonce_len)) {
wpa_printf(MSG_ERROR, "DPP: Failed to generate R-nonce");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: R-nonce", auth->r_nonce, nonce_len);
auth->own_protocol_key = dpp_gen_keypair(auth->curve);
if (!auth->own_protocol_key)
goto fail;
pr = dpp_get_pubkey_point(auth->own_protocol_key, 0);
if (!pr)
goto fail;
/* ECDH: N = pR * PI */
ctx = EVP_PKEY_CTX_new(auth->own_protocol_key, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, auth->peer_protocol_key) != 1 ||
EVP_PKEY_derive(ctx, NULL, &secret_len) != 1 ||
secret_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, auth->Nx, &secret_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
EVP_PKEY_CTX_free(ctx);
ctx = NULL;
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (N.x)",
auth->Nx, auth->secret_len);
if (dpp_derive_k2(auth->Nx, auth->secret_len, auth->k2,
auth->curve->hash_len) < 0)
goto fail;
if (auth->own_bi && auth->peer_bi) {
/* Mutual authentication */
if (dpp_auth_derive_l_responder(auth) < 0)
goto fail;
}
if (dpp_derive_ke(auth, auth->ke, auth->curve->hash_len) < 0)
goto fail;
/* R-auth = H(I-nonce | R-nonce | PI.x | PR.x | [BI.x |] BR.x | 0) */
WPA_PUT_LE16(r_auth, DPP_ATTR_R_AUTH_TAG);
WPA_PUT_LE16(&r_auth[2], auth->curve->hash_len);
if (dpp_gen_r_auth(auth, r_auth + 4) < 0 ||
aes_siv_encrypt(auth->ke, auth->curve->hash_len,
r_auth, 4 + auth->curve->hash_len,
0, NULL, NULL, wrapped_r_auth) < 0)
goto fail;
wrapped_r_auth_len = 4 + auth->curve->hash_len + AES_BLOCK_SIZE;
wpa_hexdump(MSG_DEBUG, "DPP: {R-auth}ke",
wrapped_r_auth, wrapped_r_auth_len);
/* Build DPP Authentication Response frame attributes */
attr_len = 4 + 1 + 2 * (4 + SHA256_MAC_LEN) +
4 + wpabuf_len(pr) + 4 + sizeof(wrapped_data);
msg = dpp_alloc_msg(DPP_PA_AUTHENTICATION_RESP, attr_len);
if (!msg)
goto fail;
wpabuf_free(auth->resp_msg);
auth->resp_msg = msg;
attr_start = wpabuf_put(msg, 0);
/* DPP Status */
wpabuf_put_le16(msg, DPP_ATTR_STATUS);
wpabuf_put_le16(msg, 1);
wpabuf_put_u8(msg, DPP_STATUS_OK);
/* Responder Bootstrapping Key Hash */
wpabuf_put_le16(msg, DPP_ATTR_R_BOOTSTRAP_KEY_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, auth->own_bi->pubkey_hash, SHA256_MAC_LEN);
if (auth->peer_bi) {
/* Mutual authentication */
/* Initiator Bootstrapping Key Hash */
wpabuf_put_le16(msg, DPP_ATTR_I_BOOTSTRAP_KEY_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, auth->peer_bi->pubkey_hash,
SHA256_MAC_LEN);
}
/* Responder Protocol Key */
wpabuf_put_le16(msg, DPP_ATTR_R_PROTOCOL_KEY);
wpabuf_put_le16(msg, wpabuf_len(pr));
wpabuf_put_buf(msg, pr);
wpabuf_free(pr);
pr = NULL;
attr_end = wpabuf_put(msg, 0);
/* Wrapped data ({R-nonce, I-nonce, R-capabilities, {R-auth}ke}k2) */
pos = clear;
/* R-nonce */
WPA_PUT_LE16(pos, DPP_ATTR_R_NONCE);
pos += 2;
WPA_PUT_LE16(pos, nonce_len);
pos += 2;
os_memcpy(pos, auth->r_nonce, nonce_len);
pos += nonce_len;
/* I-nonce */
WPA_PUT_LE16(pos, DPP_ATTR_I_NONCE);
pos += 2;
WPA_PUT_LE16(pos, nonce_len);
pos += 2;
os_memcpy(pos, auth->i_nonce, nonce_len);
pos += nonce_len;
/* R-capabilities */
WPA_PUT_LE16(pos, DPP_ATTR_R_CAPABILITIES);
pos += 2;
WPA_PUT_LE16(pos, 1);
pos += 2;
auth->r_capab = auth->configurator ? DPP_CAPAB_CONFIGURATOR :
DPP_CAPAB_ENROLLEE;
*pos++ = auth->r_capab;
/* {R-auth}ke */
WPA_PUT_LE16(pos, DPP_ATTR_WRAPPED_DATA);
pos += 2;
WPA_PUT_LE16(pos, wrapped_r_auth_len);
pos += 2;
os_memcpy(pos, wrapped_r_auth, wrapped_r_auth_len);
pos += wrapped_r_auth_len;
/* OUI, OUI type, Crypto Suite, DPP frame type */
addr[0] = wpabuf_head_u8(msg) + 2;
len[0] = 3 + 1 + 1 + 1;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
/* Attributes before Wrapped Data */
addr[1] = attr_start;
len[1] = attr_end - attr_start;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
siv_len = pos - clear;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext", clear, siv_len);
if (aes_siv_encrypt(auth->k2, auth->curve->hash_len, clear, siv_len,
2, addr, len, wrapped_data) < 0)
goto fail;
siv_len += AES_BLOCK_SIZE;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, siv_len);
wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
wpabuf_put_le16(msg, siv_len);
wpabuf_put_data(msg, wrapped_data, siv_len);
wpa_hexdump_buf(MSG_DEBUG,
"DPP: Authentication Response frame attributes", msg);
return 0;
fail:
wpabuf_free(pr);
return -1;
}
static int dpp_auth_build_resp_status(struct dpp_authentication *auth,
enum dpp_status_error status)
{
size_t nonce_len;
struct wpabuf *msg;
#define DPP_AUTH_RESP_CLEAR_LEN2 4 + DPP_MAX_NONCE_LEN + 4 + 1
u8 clear[DPP_AUTH_RESP_CLEAR_LEN2];
u8 wrapped_data[DPP_AUTH_RESP_CLEAR_LEN2 + AES_BLOCK_SIZE];
u8 *pos;
const u8 *addr[2];
size_t len[2], siv_len, attr_len;
u8 *attr_start, *attr_end;
wpa_printf(MSG_DEBUG, "DPP: Build Authentication Response");
/* Build DPP Authentication Response frame attributes */
attr_len = 4 + 1 + 2 * (4 + SHA256_MAC_LEN) + 4 + sizeof(wrapped_data);
msg = dpp_alloc_msg(DPP_PA_AUTHENTICATION_RESP, attr_len);
if (!msg)
goto fail;
wpabuf_free(auth->resp_msg);
auth->resp_msg = msg;
attr_start = wpabuf_put(msg, 0);
/* DPP Status */
wpabuf_put_le16(msg, DPP_ATTR_STATUS);
wpabuf_put_le16(msg, 1);
wpabuf_put_u8(msg, status);
/* Responder Bootstrapping Key Hash */
wpabuf_put_le16(msg, DPP_ATTR_R_BOOTSTRAP_KEY_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, auth->own_bi->pubkey_hash, SHA256_MAC_LEN);
if (auth->peer_bi) {
/* Mutual authentication */
/* Initiator Bootstrapping Key Hash */
wpabuf_put_le16(msg, DPP_ATTR_I_BOOTSTRAP_KEY_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, auth->peer_bi->pubkey_hash,
SHA256_MAC_LEN);
}
attr_end = wpabuf_put(msg, 0);
/* Wrapped data ({I-nonce, R-capabilities}k1) */
pos = clear;
/* I-nonce */
nonce_len = auth->curve->nonce_len;
WPA_PUT_LE16(pos, DPP_ATTR_I_NONCE);
pos += 2;
WPA_PUT_LE16(pos, nonce_len);
pos += 2;
os_memcpy(pos, auth->i_nonce, nonce_len);
pos += nonce_len;
/* R-capabilities */
WPA_PUT_LE16(pos, DPP_ATTR_R_CAPABILITIES);
pos += 2;
WPA_PUT_LE16(pos, 1);
pos += 2;
auth->r_capab = auth->configurator ? DPP_CAPAB_CONFIGURATOR :
DPP_CAPAB_ENROLLEE;
*pos++ = auth->r_capab;
/* OUI, OUI type, Crypto Suite, DPP frame type */
addr[0] = wpabuf_head_u8(msg) + 2;
len[0] = 3 + 1 + 1 + 1;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
/* Attributes before Wrapped Data */
addr[1] = attr_start;
len[1] = attr_end - attr_start;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
siv_len = pos - clear;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext", clear, siv_len);
if (aes_siv_encrypt(auth->k1, auth->curve->hash_len, clear, siv_len,
2, addr, len, wrapped_data) < 0)
goto fail;
siv_len += AES_BLOCK_SIZE;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, siv_len);
wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
wpabuf_put_le16(msg, siv_len);
wpabuf_put_data(msg, wrapped_data, siv_len);
wpa_hexdump_buf(MSG_DEBUG,
"DPP: Authentication Response frame attributes", msg);
return 0;
fail:
return -1;
}
struct dpp_authentication *
dpp_auth_req_rx(void *msg_ctx, u8 dpp_allowed_roles, int qr_mutual,
struct dpp_bootstrap_info *peer_bi,
struct dpp_bootstrap_info *own_bi,
unsigned int freq, const u8 *hdr, const u8 *attr_start,
const u8 *wrapped_data, u16 wrapped_data_len)
{
EVP_PKEY *pi = NULL;
EVP_PKEY_CTX *ctx = NULL;
size_t secret_len;
const u8 *addr[2];
size_t len[2];
u8 *unwrapped = NULL;
size_t unwrapped_len = 0;
const u8 *i_proto, *i_nonce, *i_capab, *i_bootstrap;
u16 i_proto_len, i_nonce_len, i_capab_len, i_bootstrap_len;
struct dpp_authentication *auth = NULL;
size_t attr_len;
if (wrapped_data_len < AES_BLOCK_SIZE)
return NULL;
attr_len = wrapped_data - 4 - attr_start;
auth = os_zalloc(sizeof(*auth));
if (!auth)
goto fail;
auth->msg_ctx = msg_ctx;
auth->peer_bi = peer_bi;
auth->own_bi = own_bi;
auth->curve = own_bi->curve;
auth->curr_freq = freq;
i_proto = dpp_get_attr(attr_start, attr_len, DPP_ATTR_I_PROTOCOL_KEY,
&i_proto_len);
if (!i_proto) {
wpa_printf(MSG_DEBUG,
"DPP: Missing required Initiator Protocol Key attribute");
goto fail;
}
wpa_hexdump(MSG_MSGDUMP, "DPP: Initiator Protocol Key",
i_proto, i_proto_len);
/* M = bR * PI */
pi = dpp_set_pubkey_point(own_bi->pubkey, i_proto, i_proto_len);
if (!pi) {
wpa_printf(MSG_DEBUG, "DPP: Invalid Initiator Protocol Key");
goto fail;
}
dpp_debug_print_key("Peer (Initiator) Protocol Key", pi);
ctx = EVP_PKEY_CTX_new(own_bi->pubkey, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, pi) != 1 ||
EVP_PKEY_derive(ctx, NULL, &secret_len) != 1 ||
secret_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, auth->Mx, &secret_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
auth->secret_len = secret_len;
EVP_PKEY_CTX_free(ctx);
ctx = NULL;
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (M.x)",
auth->Mx, auth->secret_len);
if (dpp_derive_k1(auth->Mx, auth->secret_len, auth->k1,
auth->curve->hash_len) < 0)
goto fail;
addr[0] = hdr;
len[0] = DPP_HDR_LEN;
addr[1] = attr_start;
len[1] = attr_len;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, wrapped_data_len);
unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
unwrapped = os_malloc(unwrapped_len);
if (!unwrapped)
goto fail;
if (aes_siv_decrypt(auth->k1, auth->curve->hash_len,
wrapped_data, wrapped_data_len,
2, addr, len, unwrapped) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped, unwrapped_len);
if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in unwrapped data");
goto fail;
}
i_nonce = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_I_NONCE,
&i_nonce_len);
if (!i_nonce || i_nonce_len != auth->curve->nonce_len) {
wpa_printf(MSG_DEBUG, "DPP: Missing or invalid I-nonce");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: I-nonce", i_nonce, i_nonce_len);
os_memcpy(auth->i_nonce, i_nonce, i_nonce_len);
i_capab = dpp_get_attr(unwrapped, unwrapped_len,
DPP_ATTR_I_CAPABILITIES,
&i_capab_len);
if (!i_capab || i_capab_len < 1) {
wpa_printf(MSG_DEBUG, "DPP: Missing or invalid I-capabilities");
goto fail;
}
auth->i_capab = i_capab[0];
wpa_printf(MSG_DEBUG, "DPP: I-capabilities: 0x%02x", auth->i_capab);
bin_clear_free(unwrapped, unwrapped_len);
unwrapped = NULL;
switch (auth->i_capab & DPP_CAPAB_ROLE_MASK) {
case DPP_CAPAB_ENROLLEE:
if (!(dpp_allowed_roles & DPP_CAPAB_CONFIGURATOR)) {
wpa_printf(MSG_DEBUG,
"DPP: Local policy does not allow Configurator role");
goto not_compatible;
}
wpa_printf(MSG_DEBUG, "DPP: Acting as Configurator");
auth->configurator = 1;
break;
case DPP_CAPAB_CONFIGURATOR:
if (!(dpp_allowed_roles & DPP_CAPAB_ENROLLEE)) {
wpa_printf(MSG_DEBUG,
"DPP: Local policy does not allow Enrollee role");
goto not_compatible;
}
wpa_printf(MSG_DEBUG, "DPP: Acting as Enrollee");
auth->configurator = 0;
break;
default:
wpa_printf(MSG_DEBUG, "DPP: Unexpected role in I-capabilities");
goto not_compatible;
}
auth->peer_protocol_key = pi;
pi = NULL;
if (qr_mutual && !peer_bi && own_bi->type == DPP_BOOTSTRAP_QR_CODE) {
char hex[SHA256_MAC_LEN * 2 + 1];
wpa_printf(MSG_DEBUG,
"DPP: Mutual authentication required with QR Codes, but peer info is not yet available - request more time");
if (dpp_auth_build_resp_status(auth,
DPP_STATUS_RESPONSE_PENDING) < 0)
goto fail;
i_bootstrap = dpp_get_attr(attr_start, attr_len,
DPP_ATTR_I_BOOTSTRAP_KEY_HASH,
&i_bootstrap_len);
if (i_bootstrap && i_bootstrap_len == SHA256_MAC_LEN) {
auth->response_pending = 1;
os_memcpy(auth->waiting_pubkey_hash,
i_bootstrap, i_bootstrap_len);
wpa_snprintf_hex(hex, sizeof(hex), i_bootstrap,
i_bootstrap_len);
} else {
hex[0] = '\0';
}
wpa_msg(auth->msg_ctx, MSG_INFO, DPP_EVENT_SCAN_PEER_QR_CODE
"%s", hex);
return auth;
}
if (dpp_auth_build_resp(auth) < 0)
goto fail;
return auth;
not_compatible:
wpa_msg(auth->msg_ctx, MSG_INFO, DPP_EVENT_NOT_COMPATIBLE
"i-capab=0x%02x", auth->i_capab);
if (dpp_allowed_roles & DPP_CAPAB_CONFIGURATOR)
auth->configurator = 1;
else
auth->configurator = 0;
auth->peer_protocol_key = pi;
pi = NULL;
if (dpp_auth_build_resp_status(auth, DPP_STATUS_NOT_COMPATIBLE) < 0)
goto fail;
auth->remove_on_tx_status = 1;
return auth;
fail:
bin_clear_free(unwrapped, unwrapped_len);
EVP_PKEY_free(pi);
EVP_PKEY_CTX_free(ctx);
dpp_auth_deinit(auth);
return NULL;
}
int dpp_notify_new_qr_code(struct dpp_authentication *auth,
struct dpp_bootstrap_info *peer_bi)
{
if (!auth || !auth->response_pending ||
os_memcmp(auth->waiting_pubkey_hash, peer_bi->pubkey_hash,
SHA256_MAC_LEN) != 0)
return 0;
wpa_printf(MSG_DEBUG,
"DPP: New scanned QR Code has matching public key that was needed to continue DPP Authentication exchange with "
MACSTR, MAC2STR(auth->peer_mac_addr));
auth->peer_bi = peer_bi;
if (dpp_auth_build_resp(auth) < 0)
return -1;
return 1;
}
static struct wpabuf * dpp_auth_build_conf(struct dpp_authentication *auth)
{
struct wpabuf *msg;
u8 i_auth[4 + DPP_MAX_HASH_LEN];
size_t i_auth_len;
const u8 *addr[2];
size_t len[2], attr_len;
u8 *wrapped_i_auth;
u8 *attr_start, *attr_end;
wpa_printf(MSG_DEBUG, "DPP: Build Authentication Confirmation");
i_auth_len = 4 + auth->curve->hash_len;
/* Build DPP Authentication Confirmation frame attributes */
attr_len = 4 + 1 + 2 * (4 + SHA256_MAC_LEN) +
4 + i_auth_len + AES_BLOCK_SIZE;
msg = dpp_alloc_msg(DPP_PA_AUTHENTICATION_CONF, attr_len);
if (!msg)
goto fail;
attr_start = wpabuf_put(msg, 0);
/* DPP Status */
wpabuf_put_le16(msg, DPP_ATTR_STATUS);
wpabuf_put_le16(msg, 1);
wpabuf_put_u8(msg, DPP_STATUS_OK);
/* Responder Bootstrapping Key Hash */
wpabuf_put_le16(msg, DPP_ATTR_R_BOOTSTRAP_KEY_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, auth->peer_bi->pubkey_hash, SHA256_MAC_LEN);
if (auth->own_bi) {
/* Mutual authentication */
/* Initiator Bootstrapping Key Hash */
wpabuf_put_le16(msg, DPP_ATTR_I_BOOTSTRAP_KEY_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, auth->own_bi->pubkey_hash, SHA256_MAC_LEN);
}
attr_end = wpabuf_put(msg, 0);
/* OUI, OUI type, Crypto Suite, DPP frame type */
addr[0] = wpabuf_head_u8(msg) + 2;
len[0] = 3 + 1 + 1 + 1;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
/* Attributes before Wrapped Data */
addr[1] = attr_start;
len[1] = attr_end - attr_start;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
wpabuf_put_le16(msg, i_auth_len + AES_BLOCK_SIZE);
wrapped_i_auth = wpabuf_put(msg, i_auth_len + AES_BLOCK_SIZE);
/* I-auth = H(R-nonce | I-nonce | PR.x | PI.x | BR.x | [BI.x |] 1) */
WPA_PUT_LE16(i_auth, DPP_ATTR_I_AUTH_TAG);
WPA_PUT_LE16(&i_auth[2], auth->curve->hash_len);
if (dpp_gen_i_auth(auth, i_auth + 4) < 0 ||
aes_siv_encrypt(auth->ke, auth->curve->hash_len,
i_auth, i_auth_len,
2, addr, len, wrapped_i_auth) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: {I-auth}ke",
wrapped_i_auth, i_auth_len + AES_BLOCK_SIZE);
wpa_hexdump_buf(MSG_DEBUG,
"DPP: Authentication Confirmation frame attributes",
msg);
dpp_auth_success(auth);
return msg;
fail:
return NULL;
}
static void
dpp_auth_resp_rx_status(struct dpp_authentication *auth, const u8 *hdr,
const u8 *attr_start, size_t attr_len,
const u8 *wrapped_data, u16 wrapped_data_len,
enum dpp_status_error status)
{
const u8 *addr[2];
size_t len[2];
u8 *unwrapped = NULL;
size_t unwrapped_len = 0;
const u8 *i_nonce, *r_capab;
u16 i_nonce_len, r_capab_len;
if (status == DPP_STATUS_NOT_COMPATIBLE) {
wpa_printf(MSG_DEBUG,
"DPP: Responder reported incompatible roles");
} else if (status == DPP_STATUS_RESPONSE_PENDING) {
wpa_printf(MSG_DEBUG,
"DPP: Responder reported more time needed");
} else {
wpa_printf(MSG_DEBUG,
"DPP: Responder reported failure (status %d)",
status);
return;
}
addr[0] = hdr;
len[0] = DPP_HDR_LEN;
addr[1] = attr_start;
len[1] = attr_len;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, wrapped_data_len);
unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
unwrapped = os_malloc(unwrapped_len);
if (!unwrapped)
goto fail;
if (aes_siv_decrypt(auth->k1, auth->curve->hash_len,
wrapped_data, wrapped_data_len,
2, addr, len, unwrapped) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped, unwrapped_len);
if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in unwrapped data");
goto fail;
}
i_nonce = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_I_NONCE,
&i_nonce_len);
if (!i_nonce || i_nonce_len != auth->curve->nonce_len) {
wpa_printf(MSG_DEBUG, "DPP: Missing or invalid I-nonce");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: I-nonce", i_nonce, i_nonce_len);
if (os_memcmp(auth->i_nonce, i_nonce, i_nonce_len) != 0) {
wpa_printf(MSG_DEBUG, "DPP: I-nonce mismatch");
goto fail;
}
r_capab = dpp_get_attr(unwrapped, unwrapped_len,
DPP_ATTR_R_CAPABILITIES,
&r_capab_len);
if (!r_capab || r_capab_len < 1) {
wpa_printf(MSG_DEBUG, "DPP: Missing or invalid R-capabilities");
goto fail;
}
auth->r_capab = r_capab[0];
wpa_printf(MSG_DEBUG, "DPP: R-capabilities: 0x%02x", auth->r_capab);
if (status == DPP_STATUS_NOT_COMPATIBLE) {
wpa_msg(auth->msg_ctx, MSG_INFO, DPP_EVENT_NOT_COMPATIBLE
"r-capab=0x%02x", auth->r_capab);
} else if (status == DPP_STATUS_RESPONSE_PENDING) {
wpa_printf(MSG_DEBUG,
"DPP: Continue waiting for full DPP Authentication Response");
wpa_msg(auth->msg_ctx, MSG_INFO, DPP_EVENT_RESPONSE_PENDING);
}
fail:
bin_clear_free(unwrapped, unwrapped_len);
}
struct wpabuf *
dpp_auth_resp_rx(struct dpp_authentication *auth, const u8 *hdr,
const u8 *attr_start, size_t attr_len)
{
EVP_PKEY *pr;
EVP_PKEY_CTX *ctx = NULL;
size_t secret_len;
const u8 *addr[2];
size_t len[2];
u8 *unwrapped = NULL, *unwrapped2 = NULL;
size_t unwrapped_len = 0, unwrapped2_len = 0;
const u8 *r_bootstrap, *i_bootstrap, *wrapped_data, *status, *r_proto,
*r_nonce, *i_nonce, *r_capab, *wrapped2, *r_auth;
u16 r_bootstrap_len, i_bootstrap_len, wrapped_data_len, status_len,
r_proto_len, r_nonce_len, i_nonce_len, r_capab_len,
wrapped2_len, r_auth_len;
u8 r_auth2[DPP_MAX_HASH_LEN];
wrapped_data = dpp_get_attr(attr_start, attr_len, DPP_ATTR_WRAPPED_DATA,
&wrapped_data_len);
if (!wrapped_data) {
wpa_printf(MSG_DEBUG,
"DPP: Missing required Wrapped data attribute");
return NULL;
}
wpa_hexdump(MSG_DEBUG, "DPP: Wrapped data",
wrapped_data, wrapped_data_len);
if (wrapped_data_len < AES_BLOCK_SIZE)
return NULL;
attr_len = wrapped_data - 4 - attr_start;
r_bootstrap = dpp_get_attr(attr_start, attr_len,
DPP_ATTR_R_BOOTSTRAP_KEY_HASH,
&r_bootstrap_len);
if (!r_bootstrap || r_bootstrap_len != SHA256_MAC_LEN) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required Responder Bootstrapping Key Hash attribute");
return NULL;
}
wpa_hexdump(MSG_DEBUG, "DPP: Responder Bootstrapping Key Hash",
r_bootstrap, r_bootstrap_len);
if (os_memcmp(r_bootstrap, auth->peer_bi->pubkey_hash,
SHA256_MAC_LEN) != 0) {
wpa_hexdump(MSG_DEBUG,
"DPP: Expected Responder Bootstrapping Key Hash",
auth->peer_bi->pubkey_hash, SHA256_MAC_LEN);
return NULL;
}
i_bootstrap = dpp_get_attr(attr_start, attr_len,
DPP_ATTR_I_BOOTSTRAP_KEY_HASH,
&i_bootstrap_len);
if (i_bootstrap) {
if (i_bootstrap_len != SHA256_MAC_LEN) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid Initiator Bootstrapping Key Hash attribute");
return NULL;
}
wpa_hexdump(MSG_MSGDUMP,
"DPP: Initiator Bootstrapping Key Hash",
i_bootstrap, i_bootstrap_len);
if (!auth->own_bi ||
os_memcmp(i_bootstrap, auth->own_bi->pubkey_hash,
SHA256_MAC_LEN) != 0) {
wpa_printf(MSG_DEBUG,
"DPP: Initiator Bootstrapping Key Hash attribute did not match");
return NULL;
}
}
status = dpp_get_attr(attr_start, attr_len, DPP_ATTR_STATUS,
&status_len);
if (!status || status_len < 1) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required DPP Status attribute");
return NULL;
}
wpa_printf(MSG_DEBUG, "DPP: Status %u", status[0]);
auth->auth_resp_status = status[0];
if (status[0] != DPP_STATUS_OK) {
dpp_auth_resp_rx_status(auth, hdr, attr_start,
attr_len, wrapped_data,
wrapped_data_len, status[0]);
return NULL;
}
r_proto = dpp_get_attr(attr_start, attr_len, DPP_ATTR_R_PROTOCOL_KEY,
&r_proto_len);
if (!r_proto) {
wpa_printf(MSG_DEBUG,
"DPP: Missing required Responder Protocol Key attribute");
return NULL;
}
wpa_hexdump(MSG_MSGDUMP, "DPP: Responder Protocol Key",
r_proto, r_proto_len);
/* N = pI * PR */
pr = dpp_set_pubkey_point(auth->own_protocol_key, r_proto, r_proto_len);
if (!pr) {
wpa_printf(MSG_DEBUG, "DPP: Invalid Responder Protocol Key");
return NULL;
}
dpp_debug_print_key("Peer (Responder) Protocol Key", pr);
ctx = EVP_PKEY_CTX_new(auth->own_protocol_key, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, pr) != 1 ||
EVP_PKEY_derive(ctx, NULL, &secret_len) != 1 ||
secret_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, auth->Nx, &secret_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
EVP_PKEY_CTX_free(ctx);
ctx = NULL;
auth->peer_protocol_key = pr;
pr = NULL;
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (N.x)",
auth->Nx, auth->secret_len);
if (dpp_derive_k2(auth->Nx, auth->secret_len, auth->k2,
auth->curve->hash_len) < 0)
goto fail;
addr[0] = hdr;
len[0] = DPP_HDR_LEN;
addr[1] = attr_start;
len[1] = attr_len;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, wrapped_data_len);
unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
unwrapped = os_malloc(unwrapped_len);
if (!unwrapped)
goto fail;
if (aes_siv_decrypt(auth->k2, auth->curve->hash_len,
wrapped_data, wrapped_data_len,
2, addr, len, unwrapped) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped, unwrapped_len);
if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in unwrapped data");
goto fail;
}
r_nonce = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_R_NONCE,
&r_nonce_len);
if (!r_nonce || r_nonce_len != auth->curve->nonce_len) {
wpa_printf(MSG_DEBUG, "DPP: Missing or invalid R-nonce");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: R-nonce", r_nonce, r_nonce_len);
os_memcpy(auth->r_nonce, r_nonce, r_nonce_len);
i_nonce = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_I_NONCE,
&i_nonce_len);
if (!i_nonce || i_nonce_len != auth->curve->nonce_len) {
wpa_printf(MSG_DEBUG, "DPP: Missing or invalid I-nonce");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: I-nonce", i_nonce, i_nonce_len);
if (os_memcmp(auth->i_nonce, i_nonce, i_nonce_len) != 0) {
wpa_printf(MSG_DEBUG, "DPP: I-nonce mismatch");
goto fail;
}
if (auth->own_bi && auth->peer_bi) {
/* Mutual authentication */
if (dpp_auth_derive_l_initiator(auth) < 0)
goto fail;
}
if (dpp_derive_ke(auth, auth->ke, auth->curve->hash_len) < 0)
goto fail;
r_capab = dpp_get_attr(unwrapped, unwrapped_len,
DPP_ATTR_R_CAPABILITIES,
&r_capab_len);
if (!r_capab || r_capab_len < 1) {
wpa_printf(MSG_DEBUG, "DPP: Missing or invalid R-capabilities");
goto fail;
}
auth->r_capab = r_capab[0];
wpa_printf(MSG_DEBUG, "DPP: R-capabilities: 0x%02x", auth->r_capab);
if ((auth->configurator && (auth->r_capab & DPP_CAPAB_CONFIGURATOR)) ||
(!auth->configurator && (auth->r_capab & DPP_CAPAB_ENROLLEE))) {
wpa_printf(MSG_DEBUG, "DPP: Incompatible role selection");
goto fail;
}
wrapped2 = dpp_get_attr(unwrapped, unwrapped_len,
DPP_ATTR_WRAPPED_DATA, &wrapped2_len);
if (!wrapped2 || wrapped2_len < AES_BLOCK_SIZE) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid Secondary Wrapped Data");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped2, wrapped2_len);
unwrapped2_len = wrapped2_len - AES_BLOCK_SIZE;
unwrapped2 = os_malloc(unwrapped2_len);
if (!unwrapped2)
goto fail;
if (aes_siv_decrypt(auth->ke, auth->curve->hash_len,
wrapped2, wrapped2_len,
0, NULL, NULL, unwrapped2) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped2, unwrapped2_len);
if (dpp_check_attrs(unwrapped2, unwrapped2_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in secondary unwrapped data");
goto fail;
}
r_auth = dpp_get_attr(unwrapped2, unwrapped2_len, DPP_ATTR_R_AUTH_TAG,
&r_auth_len);
if (!r_auth || r_auth_len != auth->curve->hash_len) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid Responder Authenticating Tag");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: Received Responder Authenticating Tag",
r_auth, r_auth_len);
/* R-auth' = H(I-nonce | R-nonce | PI.x | PR.x | [BI.x |] BR.x | 0) */
if (dpp_gen_r_auth(auth, r_auth2) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: Calculated Responder Authenticating Tag",
r_auth2, r_auth_len);
if (os_memcmp(r_auth, r_auth2, r_auth_len) != 0) {
wpa_printf(MSG_DEBUG,
"DPP: Mismatching Responder Authenticating Tag");
goto fail;
}
bin_clear_free(unwrapped, unwrapped_len);
bin_clear_free(unwrapped2, unwrapped2_len);
return dpp_auth_build_conf(auth);
fail:
bin_clear_free(unwrapped, unwrapped_len);
bin_clear_free(unwrapped2, unwrapped2_len);
EVP_PKEY_free(pr);
EVP_PKEY_CTX_free(ctx);
return NULL;
}
int dpp_auth_conf_rx(struct dpp_authentication *auth, const u8 *hdr,
const u8 *attr_start, size_t attr_len)
{
const u8 *r_bootstrap, *i_bootstrap, *wrapped_data, *status, *i_auth;
u16 r_bootstrap_len, i_bootstrap_len, wrapped_data_len, status_len,
i_auth_len;
const u8 *addr[2];
size_t len[2];
u8 *unwrapped = NULL;
size_t unwrapped_len = 0;
u8 i_auth2[DPP_MAX_HASH_LEN];
wrapped_data = dpp_get_attr(attr_start, attr_len, DPP_ATTR_WRAPPED_DATA,
&wrapped_data_len);
if (!wrapped_data) {
wpa_printf(MSG_DEBUG,
"DPP: Missing required Wrapped data attribute");
return -1;
}
wpa_hexdump(MSG_DEBUG, "DPP: Wrapped data",
wrapped_data, wrapped_data_len);
if (wrapped_data_len < AES_BLOCK_SIZE)
return -1;
attr_len = wrapped_data - 4 - attr_start;
r_bootstrap = dpp_get_attr(attr_start, attr_len,
DPP_ATTR_R_BOOTSTRAP_KEY_HASH,
&r_bootstrap_len);
if (!r_bootstrap || r_bootstrap > wrapped_data ||
r_bootstrap_len != SHA256_MAC_LEN) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required Responder Bootstrapping Key Hash attribute");
return -1;
}
wpa_hexdump(MSG_DEBUG, "DPP: Responder Bootstrapping Key Hash",
r_bootstrap, r_bootstrap_len);
if (os_memcmp(r_bootstrap, auth->own_bi->pubkey_hash,
SHA256_MAC_LEN) != 0) {
wpa_hexdump(MSG_DEBUG,
"DPP: Expected Responder Bootstrapping Key Hash",
auth->peer_bi->pubkey_hash, SHA256_MAC_LEN);
return -1;
}
i_bootstrap = dpp_get_attr(attr_start, attr_len,
DPP_ATTR_I_BOOTSTRAP_KEY_HASH,
&i_bootstrap_len);
if (i_bootstrap) {
if (i_bootstrap > wrapped_data ||
i_bootstrap_len != SHA256_MAC_LEN) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid Initiator Bootstrapping Key Hash attribute");
return -1;
}
wpa_hexdump(MSG_MSGDUMP,
"DPP: Initiator Bootstrapping Key Hash",
i_bootstrap, i_bootstrap_len);
if (!auth->peer_bi ||
os_memcmp(i_bootstrap, auth->peer_bi->pubkey_hash,
SHA256_MAC_LEN) != 0) {
wpa_printf(MSG_DEBUG,
"DPP: Initiator Bootstrapping Key Hash attribute did not match");
return -1;
}
}
status = dpp_get_attr(attr_start, attr_len, DPP_ATTR_STATUS,
&status_len);
if (!status || status_len < 1) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required DPP Status attribute");
return -1;
}
wpa_printf(MSG_DEBUG, "DPP: Status %u", status[0]);
if (status[0] != DPP_STATUS_OK) {
wpa_printf(MSG_DEBUG, "DPP: Authentication failed");
return -1;
}
addr[0] = hdr;
len[0] = DPP_HDR_LEN;
addr[1] = attr_start;
len[1] = attr_len;
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, wrapped_data_len);
unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
unwrapped = os_malloc(unwrapped_len);
if (!unwrapped)
return -1;
if (aes_siv_decrypt(auth->ke, auth->curve->hash_len,
wrapped_data, wrapped_data_len,
2, addr, len, unwrapped) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped, unwrapped_len);
if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in unwrapped data");
goto fail;
}
i_auth = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_I_AUTH_TAG,
&i_auth_len);
if (!i_auth || i_auth_len != auth->curve->hash_len) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid Initiator Authenticating Tag");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: Received Initiator Authenticating Tag",
i_auth, i_auth_len);
/* I-auth' = H(R-nonce | I-nonce | PR.x | PI.x | BR.x | [BI.x |] 1) */
if (dpp_gen_i_auth(auth, i_auth2) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: Calculated Initiator Authenticating Tag",
i_auth2, i_auth_len);
if (os_memcmp(i_auth, i_auth2, i_auth_len) != 0) {
wpa_printf(MSG_DEBUG,
"DPP: Mismatching Initiator Authenticating Tag");
goto fail;
}
bin_clear_free(unwrapped, unwrapped_len);
dpp_auth_success(auth);
return 0;
fail:
bin_clear_free(unwrapped, unwrapped_len);
return -1;
}
void dpp_configuration_free(struct dpp_configuration *conf)
{
if (!conf)
return;
str_clear_free(conf->passphrase);
bin_clear_free(conf, sizeof(*conf));
}
void dpp_auth_deinit(struct dpp_authentication *auth)
{
if (!auth)
return;
dpp_configuration_free(auth->conf_ap);
dpp_configuration_free(auth->conf_sta);
EVP_PKEY_free(auth->own_protocol_key);
EVP_PKEY_free(auth->peer_protocol_key);
wpabuf_free(auth->req_msg);
wpabuf_free(auth->resp_msg);
wpabuf_free(auth->conf_req);
os_free(auth->connector);
wpabuf_free(auth->net_access_key);
wpabuf_free(auth->c_sign_key);
#ifdef CONFIG_TESTING_OPTIONS
os_free(auth->config_obj_override);
os_free(auth->discovery_override);
os_free(auth->groups_override);
#endif /* CONFIG_TESTING_OPTIONS */
bin_clear_free(auth, sizeof(*auth));
}
static struct wpabuf *
dpp_build_conf_start(struct dpp_authentication *auth,
struct dpp_configuration *conf, size_t tailroom)
{
struct wpabuf *buf;
char ssid[6 * sizeof(conf->ssid) + 1];
#ifdef CONFIG_TESTING_OPTIONS
if (auth->discovery_override)
tailroom += os_strlen(auth->discovery_override);
#endif /* CONFIG_TESTING_OPTIONS */
buf = wpabuf_alloc(200 + tailroom);
if (!buf)
return NULL;
wpabuf_put_str(buf, "{\"wi-fi_tech\":\"infra\",\"discovery\":");
#ifdef CONFIG_TESTING_OPTIONS
if (auth->discovery_override) {
wpa_printf(MSG_DEBUG, "DPP: TESTING - discovery override: '%s'",
auth->discovery_override);
wpabuf_put_str(buf, auth->discovery_override);
wpabuf_put_u8(buf, ',');
return buf;
}
#endif /* CONFIG_TESTING_OPTIONS */
wpabuf_put_str(buf, "{\"ssid\":\"");
json_escape_string(ssid, sizeof(ssid),
(const char *) conf->ssid, conf->ssid_len);
wpabuf_put_str(buf, ssid);
wpabuf_put_str(buf, "\"");
/* TODO: optional channel information */
wpabuf_put_str(buf, "},");
return buf;
}
static int dpp_bn2bin_pad(const BIGNUM *bn, u8 *pos, size_t len)
{
int num_bytes, offset;
num_bytes = BN_num_bytes(bn);
if ((size_t) num_bytes > len)
return -1;
offset = len - num_bytes;
os_memset(pos, 0, offset);
BN_bn2bin(bn, pos + offset);
return 0;
}
static int dpp_build_jwk(struct wpabuf *buf, const char *name, EVP_PKEY *key,
const char *kid, const struct dpp_curve_params *curve)
{
struct wpabuf *pub;
const u8 *pos;
char *x = NULL, *y = NULL;
int ret = -1;
pub = dpp_get_pubkey_point(key, 0);
if (!pub)
goto fail;
pos = wpabuf_head(pub);
x = (char *) base64_url_encode(pos, curve->prime_len, NULL, 0);
pos += curve->prime_len;
y = (char *) base64_url_encode(pos, curve->prime_len, NULL, 0);
if (!x || !y)
goto fail;
wpabuf_put_str(buf, "\"");
wpabuf_put_str(buf, name);
wpabuf_put_str(buf, "\":{\"kty\":\"EC\",\"crv\":\"");
wpabuf_put_str(buf, curve->jwk_crv);
wpabuf_put_str(buf, "\",\"x\":\"");
wpabuf_put_str(buf, x);
wpabuf_put_str(buf, "\",\"y\":\"");
wpabuf_put_str(buf, y);
if (kid) {
wpabuf_put_str(buf, "\",\"kid\":\"");
wpabuf_put_str(buf, kid);
}
wpabuf_put_str(buf, "\"}");
ret = 0;
fail:
wpabuf_free(pub);
os_free(x);
os_free(y);
return ret;
}
static struct wpabuf *
dpp_build_conf_obj_dpp(struct dpp_authentication *auth, int ap,
struct dpp_configuration *conf)
{
struct wpabuf *buf = NULL;
char *signed1 = NULL, *signed2 = NULL, *signed3 = NULL;
size_t tailroom;
const struct dpp_curve_params *curve;
char jws_prot_hdr[100];
size_t signed1_len, signed2_len, signed3_len;
struct wpabuf *dppcon = NULL;
unsigned char *signature = NULL;
const unsigned char *p;
size_t signature_len;
EVP_MD_CTX *md_ctx = NULL;
ECDSA_SIG *sig = NULL;
char *dot = ".";
const EVP_MD *sign_md;
const BIGNUM *r, *s;
size_t extra_len = 1000;
if (!auth->conf) {
wpa_printf(MSG_INFO,
"DPP: No configurator specified - cannot generate DPP config object");
goto fail;
}
curve = auth->conf->curve;
if (curve->hash_len == SHA256_MAC_LEN) {
sign_md = EVP_sha256();
} else if (curve->hash_len == SHA384_MAC_LEN) {
sign_md = EVP_sha384();
} else if (curve->hash_len == SHA512_MAC_LEN) {
sign_md = EVP_sha512();
} else {
wpa_printf(MSG_DEBUG, "DPP: Unknown signature algorithm");
goto fail;
}
#ifdef CONFIG_TESTING_OPTIONS
if (auth->groups_override)
extra_len += os_strlen(auth->groups_override);
#endif /* CONFIG_TESTING_OPTIONS */
/* Connector (JSON dppCon object) */
dppcon = wpabuf_alloc(extra_len + 2 * auth->curve->prime_len * 4 / 3);
if (!dppcon)
goto fail;
#ifdef CONFIG_TESTING_OPTIONS
if (auth->groups_override) {
wpabuf_put_u8(dppcon, '{');
if (auth->groups_override) {
wpa_printf(MSG_DEBUG,
"DPP: TESTING - groups override: '%s'",
auth->groups_override);
wpabuf_put_str(dppcon, "\"groups\":");
wpabuf_put_str(dppcon, auth->groups_override);
wpabuf_put_u8(dppcon, ',');
}
goto skip_groups;
}
#endif /* CONFIG_TESTING_OPTIONS */
wpabuf_put_str(dppcon, "{\"groups\":[{\"groupId\":\"*\",");
wpabuf_printf(dppcon, "\"netRole\":\"%s\"}],", ap ? "ap" : "sta");
#ifdef CONFIG_TESTING_OPTIONS
skip_groups:
#endif /* CONFIG_TESTING_OPTIONS */
if (dpp_build_jwk(dppcon, "netAccessKey", auth->peer_protocol_key, NULL,
auth->curve) < 0) {
wpa_printf(MSG_DEBUG, "DPP: Failed to build netAccessKey JWK");
goto fail;
}
if (conf->netaccesskey_expiry) {
struct os_tm tm;
if (os_gmtime(conf->netaccesskey_expiry, &tm) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Failed to generate expiry string");
goto fail;
}
wpabuf_printf(dppcon,
",\"expiry\":\"%04u-%02u-%02uT%02u:%02u:%02uZ\"",
tm.year, tm.month, tm.day,
tm.hour, tm.min, tm.sec);
}
wpabuf_put_u8(dppcon, '}');
wpa_printf(MSG_DEBUG, "DPP: dppCon: %s",
(const char *) wpabuf_head(dppcon));
os_snprintf(jws_prot_hdr, sizeof(jws_prot_hdr),
"{\"typ\":\"dppCon\",\"kid\":\"%s\",\"alg\":\"%s\"}",
auth->conf->kid, curve->jws_alg);
signed1 = (char *) base64_url_encode((unsigned char *) jws_prot_hdr,
os_strlen(jws_prot_hdr),
&signed1_len, 0);
signed2 = (char *) base64_url_encode(wpabuf_head(dppcon),
wpabuf_len(dppcon),
&signed2_len, 0);
if (!signed1 || !signed2)
goto fail;
md_ctx = EVP_MD_CTX_create();
if (!md_ctx)
goto fail;
ERR_clear_error();
if (EVP_DigestSignInit(md_ctx, NULL, sign_md, NULL,
auth->conf->csign) != 1) {
wpa_printf(MSG_DEBUG, "DPP: EVP_DigestSignInit failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
if (EVP_DigestSignUpdate(md_ctx, signed1, signed1_len) != 1 ||
EVP_DigestSignUpdate(md_ctx, dot, 1) != 1 ||
EVP_DigestSignUpdate(md_ctx, signed2, signed2_len) != 1) {
wpa_printf(MSG_DEBUG, "DPP: EVP_DigestSignUpdate failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
if (EVP_DigestSignFinal(md_ctx, NULL, &signature_len) != 1) {
wpa_printf(MSG_DEBUG, "DPP: EVP_DigestSignFinal failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
signature = os_malloc(signature_len);
if (!signature)
goto fail;
if (EVP_DigestSignFinal(md_ctx, signature, &signature_len) != 1) {
wpa_printf(MSG_DEBUG, "DPP: EVP_DigestSignFinal failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: signedConnector ECDSA signature (DER)",
signature, signature_len);
/* Convert to raw coordinates r,s */
p = signature;
sig = d2i_ECDSA_SIG(NULL, &p, signature_len);
if (!sig)
goto fail;
ECDSA_SIG_get0(sig, &r, &s);
if (dpp_bn2bin_pad(r, signature, curve->prime_len) < 0 ||
dpp_bn2bin_pad(s, signature + curve->prime_len,
curve->prime_len) < 0)
goto fail;
signature_len = 2 * curve->prime_len;
wpa_hexdump(MSG_DEBUG, "DPP: signedConnector ECDSA signature (raw r,s)",
signature, signature_len);
signed3 = (char *) base64_url_encode(signature, signature_len,
&signed3_len, 0);
if (!signed3)
goto fail;
tailroom = 1000;
tailroom += 2 * curve->prime_len * 4 / 3 + os_strlen(auth->conf->kid);
tailroom += signed1_len + signed2_len + signed3_len;
buf = dpp_build_conf_start(auth, conf, tailroom);
if (!buf)
return NULL;
wpabuf_put_str(buf, "\"cred\":{\"akm\":\"dpp\",\"signedConnector\":\"");
wpabuf_put_str(buf, signed1);
wpabuf_put_u8(buf, '.');
wpabuf_put_str(buf, signed2);
wpabuf_put_u8(buf, '.');
wpabuf_put_str(buf, signed3);
wpabuf_put_str(buf, "\",");
if (dpp_build_jwk(buf, "csign", auth->conf->csign, auth->conf->kid,
curve) < 0) {
wpa_printf(MSG_DEBUG, "DPP: Failed to build csign JWK");
goto fail;
}
wpabuf_put_str(buf, "}}");
wpa_hexdump_ascii_key(MSG_DEBUG, "DPP: Configuration Object",
wpabuf_head(buf), wpabuf_len(buf));
out:
EVP_MD_CTX_destroy(md_ctx);
ECDSA_SIG_free(sig);
os_free(signed1);
os_free(signed2);
os_free(signed3);
os_free(signature);
wpabuf_free(dppcon);
return buf;
fail:
wpa_printf(MSG_DEBUG, "DPP: Failed to build configuration object");
wpabuf_free(buf);
buf = NULL;
goto out;
}
static struct wpabuf *
dpp_build_conf_obj_legacy(struct dpp_authentication *auth, int ap,
struct dpp_configuration *conf)
{
struct wpabuf *buf;
buf = dpp_build_conf_start(auth, conf, 1000);
if (!buf)
return NULL;
wpabuf_put_str(buf, "\"cred\":{\"akm\":\"psk\",");
if (conf->passphrase) {
char pass[63 * 6 + 1];
if (os_strlen(conf->passphrase) > 63) {
wpabuf_free(buf);
return NULL;
}
json_escape_string(pass, sizeof(pass), conf->passphrase,
os_strlen(conf->passphrase));
wpabuf_put_str(buf, "\"pass\":\"");
wpabuf_put_str(buf, pass);
wpabuf_put_str(buf, "\"");
} else {
char psk[2 * sizeof(conf->psk) + 1];
wpa_snprintf_hex(psk, sizeof(psk),
conf->psk, sizeof(conf->psk));
wpabuf_put_str(buf, "\"psk_hex\":\"");
wpabuf_put_str(buf, psk);
wpabuf_put_str(buf, "\"");
}
wpabuf_put_str(buf, "}}");
wpa_hexdump_ascii_key(MSG_DEBUG, "DPP: Configuration Object (legacy)",
wpabuf_head(buf), wpabuf_len(buf));
return buf;
}
static struct wpabuf *
dpp_build_conf_obj(struct dpp_authentication *auth, int ap)
{
struct dpp_configuration *conf;
#ifdef CONFIG_TESTING_OPTIONS
if (auth->config_obj_override) {
wpa_printf(MSG_DEBUG, "DPP: Testing - Config Object override");
return wpabuf_alloc_copy(auth->config_obj_override,
os_strlen(auth->config_obj_override));
}
#endif /* CONFIG_TESTING_OPTIONS */
conf = ap ? auth->conf_ap : auth->conf_sta;
if (!conf) {
wpa_printf(MSG_DEBUG,
"DPP: No configuration available for Enrollee(%s) - reject configuration request",
ap ? "ap" : "sta");
return NULL;
}
if (conf->dpp)
return dpp_build_conf_obj_dpp(auth, ap, conf);
return dpp_build_conf_obj_legacy(auth, ap, conf);
}
static struct wpabuf *
dpp_build_conf_resp(struct dpp_authentication *auth, const u8 *e_nonce,
u16 e_nonce_len, int ap)
{
struct wpabuf *conf;
size_t clear_len;
struct wpabuf *clear = NULL, *msg = NULL;
u8 *wrapped;
const u8 *addr[1];
size_t len[1];
enum dpp_status_error status;
conf = dpp_build_conf_obj(auth, ap);
if (conf) {
wpa_hexdump_ascii(MSG_DEBUG, "DPP: configurationObject JSON",
wpabuf_head(conf), wpabuf_len(conf));
}
status = conf ? DPP_STATUS_OK : DPP_STATUS_CONFIGURE_FAILURE;
/* { E-nonce, configurationObject}ke */
clear_len = 4 + e_nonce_len;
if (conf)
clear_len += 4 + wpabuf_len(conf);
clear = wpabuf_alloc(clear_len);
msg = wpabuf_alloc(4 + 1 + 4 + clear_len + AES_BLOCK_SIZE);
if (!clear || !msg)
goto fail;
/* E-nonce */
wpabuf_put_le16(clear, DPP_ATTR_ENROLLEE_NONCE);
wpabuf_put_le16(clear, e_nonce_len);
wpabuf_put_data(clear, e_nonce, e_nonce_len);
if (conf) {
wpabuf_put_le16(clear, DPP_ATTR_CONFIG_OBJ);
wpabuf_put_le16(clear, wpabuf_len(conf));
wpabuf_put_buf(clear, conf);
wpabuf_free(conf);
conf = NULL;
}
/* DPP Status */
wpabuf_put_le16(msg, DPP_ATTR_STATUS);
wpabuf_put_le16(msg, 1);
wpabuf_put_u8(msg, status);
addr[0] = wpabuf_head(msg);
len[0] = wpabuf_len(msg);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD", addr[0], len[0]);
wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
wpabuf_put_le16(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
wrapped = wpabuf_put(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
wpa_hexdump_buf(MSG_DEBUG, "DPP: AES-SIV cleartext", clear);
if (aes_siv_encrypt(auth->ke, auth->curve->hash_len,
wpabuf_head(clear), wpabuf_len(clear),
1, addr, len, wrapped) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped, wpabuf_len(clear) + AES_BLOCK_SIZE);
wpabuf_free(clear);
clear = NULL;
wpa_hexdump_buf(MSG_DEBUG,
"DPP: Configuration Response attributes", msg);
return msg;
fail:
wpabuf_free(conf);
wpabuf_free(clear);
wpabuf_free(msg);
return NULL;
}
struct wpabuf *
dpp_conf_req_rx(struct dpp_authentication *auth, const u8 *attr_start,
size_t attr_len)
{
const u8 *wrapped_data, *e_nonce, *config_attr;
u16 wrapped_data_len, e_nonce_len, config_attr_len;
u8 *unwrapped = NULL;
size_t unwrapped_len = 0;
struct wpabuf *resp = NULL;
struct json_token *root = NULL, *token;
int ap;
if (dpp_check_attrs(attr_start, attr_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in config request");
return NULL;
}
wrapped_data = dpp_get_attr(attr_start, attr_len, DPP_ATTR_WRAPPED_DATA,
&wrapped_data_len);
if (!wrapped_data || wrapped_data_len < AES_BLOCK_SIZE) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required Wrapped data attribute");
return NULL;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, wrapped_data_len);
unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
unwrapped = os_malloc(unwrapped_len);
if (!unwrapped)
return NULL;
if (aes_siv_decrypt(auth->ke, auth->curve->hash_len,
wrapped_data, wrapped_data_len,
0, NULL, NULL, unwrapped) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped, unwrapped_len);
if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in unwrapped data");
goto fail;
}
e_nonce = dpp_get_attr(unwrapped, unwrapped_len,
DPP_ATTR_ENROLLEE_NONCE,
&e_nonce_len);
if (!e_nonce || e_nonce_len != auth->curve->nonce_len) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid Enrollee Nonce attribute");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: Enrollee Nonce", e_nonce, e_nonce_len);
config_attr = dpp_get_attr(unwrapped, unwrapped_len,
DPP_ATTR_CONFIG_ATTR_OBJ,
&config_attr_len);
if (!config_attr) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid Config Attributes attribute");
goto fail;
}
wpa_hexdump_ascii(MSG_DEBUG, "DPP: Config Attributes",
config_attr, config_attr_len);
root = json_parse((const char *) config_attr, config_attr_len);
if (!root) {
wpa_printf(MSG_DEBUG, "DPP: Could not parse Config Attributes");
goto fail;
}
token = json_get_member(root, "name");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No Config Attributes - name");
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: Enrollee name = '%s'", token->string);
token = json_get_member(root, "wi-fi_tech");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No Config Attributes - wi-fi_tech");
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: wi-fi_tech = '%s'", token->string);
if (os_strcmp(token->string, "infra") != 0) {
wpa_printf(MSG_DEBUG, "DPP: Unsupported wi-fi_tech '%s'",
token->string);
goto fail;
}
token = json_get_member(root, "netRole");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No Config Attributes - netRole");
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: netRole = '%s'", token->string);
if (os_strcmp(token->string, "sta") == 0) {
ap = 0;
} else if (os_strcmp(token->string, "ap") == 0) {
ap = 1;
} else {
wpa_printf(MSG_DEBUG, "DPP: Unsupported netRole '%s'",
token->string);
goto fail;
}
resp = dpp_build_conf_resp(auth, e_nonce, e_nonce_len, ap);
fail:
json_free(root);
os_free(unwrapped);
return resp;
}
static struct wpabuf *
dpp_parse_jws_prot_hdr(const struct dpp_curve_params *curve,
const u8 *prot_hdr, u16 prot_hdr_len,
const EVP_MD **ret_md)
{
struct json_token *root, *token;
struct wpabuf *kid = NULL;
root = json_parse((const char *) prot_hdr, prot_hdr_len);
if (!root) {
wpa_printf(MSG_DEBUG,
"DPP: JSON parsing failed for JWS Protected Header");
goto fail;
}
if (root->type != JSON_OBJECT) {
wpa_printf(MSG_DEBUG,
"DPP: JWS Protected Header root is not an object");
goto fail;
}
token = json_get_member(root, "typ");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No typ string value found");
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: JWS Protected Header typ=%s",
token->string);
if (os_strcmp(token->string, "dppCon") != 0) {
wpa_printf(MSG_DEBUG,
"DPP: Unsupported JWS Protected Header typ=%s",
token->string);
goto fail;
}
token = json_get_member(root, "alg");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No alg string value found");
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: JWS Protected Header alg=%s",
token->string);
if (os_strcmp(token->string, curve->jws_alg) != 0) {
wpa_printf(MSG_DEBUG,
"DPP: Unexpected JWS Protected Header alg=%s (expected %s based on C-sign-key)",
token->string, curve->jws_alg);
goto fail;
}
if (os_strcmp(token->string, "ES256") == 0 ||
os_strcmp(token->string, "BS256") == 0)
*ret_md = EVP_sha256();
else if (os_strcmp(token->string, "ES384") == 0 ||
os_strcmp(token->string, "BS384") == 0)
*ret_md = EVP_sha384();
else if (os_strcmp(token->string, "ES512") == 0 ||
os_strcmp(token->string, "BS512") == 0)
*ret_md = EVP_sha512();
else
*ret_md = NULL;
if (!*ret_md) {
wpa_printf(MSG_DEBUG,
"DPP: Unsupported JWS Protected Header alg=%s",
token->string);
goto fail;
}
kid = json_get_member_base64url(root, "kid");
if (!kid) {
wpa_printf(MSG_DEBUG, "DPP: No kid string value found");
goto fail;
}
wpa_hexdump_buf(MSG_DEBUG, "DPP: JWS Protected Header kid (decoded)",
kid);
fail:
json_free(root);
return kid;
}
static int dpp_parse_cred_legacy(struct dpp_authentication *auth,
struct json_token *cred)
{
struct json_token *pass, *psk_hex;
wpa_printf(MSG_DEBUG, "DPP: Legacy akm=psk credential");
pass = json_get_member(cred, "pass");
psk_hex = json_get_member(cred, "psk_hex");
if (pass && pass->type == JSON_STRING) {
size_t len = os_strlen(pass->string);
wpa_hexdump_ascii_key(MSG_DEBUG, "DPP: Legacy passphrase",
pass->string, len);
if (len < 8 || len > 63)
return -1;
os_strlcpy(auth->passphrase, pass->string,
sizeof(auth->passphrase));
} else if (psk_hex && psk_hex->type == JSON_STRING) {
if (os_strlen(psk_hex->string) != PMK_LEN * 2 ||
hexstr2bin(psk_hex->string, auth->psk, PMK_LEN) < 0) {
wpa_printf(MSG_DEBUG, "DPP: Invalid psk_hex encoding");
return -1;
}
wpa_hexdump_key(MSG_DEBUG, "DPP: Legacy PSK",
auth->psk, PMK_LEN);
auth->psk_set = 1;
} else {
wpa_printf(MSG_DEBUG, "DPP: No pass or psk_hex strings found");
return -1;
}
return 0;
}
static EVP_PKEY * dpp_parse_jwk(struct json_token *jwk,
const struct dpp_curve_params **key_curve)
{
struct json_token *token;
const struct dpp_curve_params *curve;
struct wpabuf *x = NULL, *y = NULL;
EC_GROUP *group;
EVP_PKEY *pkey = NULL;
token = json_get_member(jwk, "kty");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No kty in JWK");
goto fail;
}
if (os_strcmp(token->string, "EC") != 0) {
wpa_printf(MSG_DEBUG, "DPP: Unexpected JWK kty '%s",
token->string);
goto fail;
}
token = json_get_member(jwk, "crv");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No crv in JWK");
goto fail;
}
curve = dpp_get_curve_jwk_crv(token->string);
if (!curve) {
wpa_printf(MSG_DEBUG, "DPP: Unsupported JWK crv '%s'",
token->string);
goto fail;
}
x = json_get_member_base64url(jwk, "x");
if (!x) {
wpa_printf(MSG_DEBUG, "DPP: No x in JWK");
goto fail;
}
wpa_hexdump_buf(MSG_DEBUG, "DPP: JWK x", x);
if (wpabuf_len(x) != curve->prime_len) {
wpa_printf(MSG_DEBUG,
"DPP: Unexpected JWK x length %u (expected %u for curve %s)",
(unsigned int) wpabuf_len(x),
(unsigned int) curve->prime_len, curve->name);
goto fail;
}
y = json_get_member_base64url(jwk, "y");
if (!y) {
wpa_printf(MSG_DEBUG, "DPP: No y in JWK");
goto fail;
}
wpa_hexdump_buf(MSG_DEBUG, "DPP: JWK y", y);
if (wpabuf_len(y) != curve->prime_len) {
wpa_printf(MSG_DEBUG,
"DPP: Unexpected JWK y length %u (expected %u for curve %s)",
(unsigned int) wpabuf_len(y),
(unsigned int) curve->prime_len, curve->name);
goto fail;
}
group = EC_GROUP_new_by_curve_name(OBJ_txt2nid(curve->name));
if (!group) {
wpa_printf(MSG_DEBUG, "DPP: Could not prepare group for JWK");
goto fail;
}
pkey = dpp_set_pubkey_point_group(group, wpabuf_head(x), wpabuf_head(y),
wpabuf_len(x));
*key_curve = curve;
fail:
wpabuf_free(x);
wpabuf_free(y);
return pkey;
}
int dpp_key_expired(const char *timestamp, os_time_t *expiry)
{
struct os_time now;
unsigned int year, month, day, hour, min, sec;
os_time_t utime;
const char *pos;
/* ISO 8601 date and time:
* <date>T<time>
* YYYY-MM-DDTHH:MM:SSZ
* YYYY-MM-DDTHH:MM:SS+03:00
*/
if (os_strlen(timestamp) < 19) {
wpa_printf(MSG_DEBUG,
"DPP: Too short timestamp - assume expired key");
return 1;
}
if (sscanf(timestamp, "%04u-%02u-%02uT%02u:%02u:%02u",
&year, &month, &day, &hour, &min, &sec) != 6) {
wpa_printf(MSG_DEBUG,
"DPP: Failed to parse expiration day - assume expired key");
return 1;
}
if (os_mktime(year, month, day, hour, min, sec, &utime) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid date/time information - assume expired key");
return 1;
}
pos = timestamp + 19;
if (*pos == 'Z' || *pos == '\0') {
/* In UTC - no need to adjust */
} else if (*pos == '-' || *pos == '+') {
int items;
/* Adjust local time to UTC */
items = sscanf(pos + 1, "%02u:%02u", &hour, &min);
if (items < 1) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid time zone designator (%s) - assume expired key",
pos);
return 1;
}
if (*pos == '-')
utime += 3600 * hour;
if (*pos == '+')
utime -= 3600 * hour;
if (items > 1) {
if (*pos == '-')
utime += 60 * min;
if (*pos == '+')
utime -= 60 * min;
}
} else {
wpa_printf(MSG_DEBUG,
"DPP: Invalid time zone designator (%s) - assume expired key",
pos);
return 1;
}
if (expiry)
*expiry = utime;
if (os_get_time(&now) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Cannot get current time - assume expired key");
return 1;
}
if (now.sec > utime) {
wpa_printf(MSG_DEBUG, "DPP: Key has expired (%lu < %lu)",
utime, now.sec);
return 1;
}
return 0;
}
static int dpp_parse_connector(struct dpp_authentication *auth,
const unsigned char *payload,
u16 payload_len)
{
struct json_token *root, *groups, *netkey, *token;
int ret = -1;
EVP_PKEY *key = NULL;
const struct dpp_curve_params *curve;
unsigned int rules = 0;
root = json_parse((const char *) payload, payload_len);
if (!root) {
wpa_printf(MSG_DEBUG, "DPP: JSON parsing of connector failed");
goto fail;
}
groups = json_get_member(root, "groups");
if (!groups || groups->type != JSON_ARRAY) {
wpa_printf(MSG_DEBUG, "DPP: No groups array found");
goto skip_groups;
}
for (token = groups->child; token; token = token->sibling) {
struct json_token *id, *role;
id = json_get_member(token, "groupId");
if (!id || id->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: Missing groupId string");
goto fail;
}
role = json_get_member(token, "netRole");
if (!role || role->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: Missing netRole string");
goto fail;
}
wpa_printf(MSG_DEBUG,
"DPP: connector group: groupId='%s' netRole='%s'",
id->string, role->string);
rules++;
}
skip_groups:
if (!rules) {
wpa_printf(MSG_DEBUG,
"DPP: Connector includes no groups");
goto fail;
}
token = json_get_member(root, "expiry");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG,
"DPP: No expiry string found - connector does not expire");
} else {
wpa_printf(MSG_DEBUG, "DPP: expiry = %s", token->string);
if (dpp_key_expired(token->string,
&auth->net_access_key_expiry)) {
wpa_printf(MSG_DEBUG,
"DPP: Connector (netAccessKey) has expired");
goto fail;
}
}
netkey = json_get_member(root, "netAccessKey");
if (!netkey || netkey->type != JSON_OBJECT) {
wpa_printf(MSG_DEBUG, "DPP: No netAccessKey object found");
goto fail;
}
key = dpp_parse_jwk(netkey, &curve);
if (!key)
goto fail;
dpp_debug_print_key("DPP: Received netAccessKey", key);
if (EVP_PKEY_cmp(key, auth->own_protocol_key) != 1) {
wpa_printf(MSG_DEBUG,
"DPP: netAccessKey in connector does not match own protocol key");
#ifdef CONFIG_TESTING_OPTIONS
if (auth->ignore_netaccesskey_mismatch) {
wpa_printf(MSG_DEBUG,
"DPP: TESTING - skip netAccessKey mismatch");
} else {
goto fail;
}
#else /* CONFIG_TESTING_OPTIONS */
goto fail;
#endif /* CONFIG_TESTING_OPTIONS */
}
ret = 0;
fail:
EVP_PKEY_free(key);
json_free(root);
return ret;
}
static int dpp_check_pubkey_match(EVP_PKEY *pub, struct wpabuf *r_hash)
{
struct wpabuf *uncomp;
int res;
u8 hash[SHA256_MAC_LEN];
const u8 *addr[1];
size_t len[1];
if (wpabuf_len(r_hash) != SHA256_MAC_LEN)
return -1;
uncomp = dpp_get_pubkey_point(pub, 1);
if (!uncomp)
return -1;
addr[0] = wpabuf_head(uncomp);
len[0] = wpabuf_len(uncomp);
wpa_hexdump(MSG_DEBUG, "DPP: Uncompressed public key",
addr[0], len[0]);
res = sha256_vector(1, addr, len, hash);
wpabuf_free(uncomp);
if (res < 0)
return -1;
if (os_memcmp(hash, wpabuf_head(r_hash), SHA256_MAC_LEN) != 0) {
wpa_printf(MSG_DEBUG,
"DPP: Received hash value does not match calculated public key hash value");
wpa_hexdump(MSG_DEBUG, "DPP: Calculated hash",
hash, SHA256_MAC_LEN);
return -1;
}
return 0;
}
static void dpp_copy_csign(struct dpp_authentication *auth, EVP_PKEY *csign)
{
unsigned char *der = NULL;
int der_len;
der_len = i2d_PUBKEY(csign, &der);
if (der_len <= 0)
return;
wpabuf_free(auth->c_sign_key);
auth->c_sign_key = wpabuf_alloc_copy(der, der_len);
OPENSSL_free(der);
}
static void dpp_copy_netaccesskey(struct dpp_authentication *auth)
{
unsigned char *der = NULL;
int der_len;
EC_KEY *eckey;
eckey = EVP_PKEY_get1_EC_KEY(auth->own_protocol_key);
if (!eckey)
return;
der_len = i2d_ECPrivateKey(eckey, &der);
if (der_len <= 0) {
EC_KEY_free(eckey);
return;
}
wpabuf_free(auth->net_access_key);
auth->net_access_key = wpabuf_alloc_copy(der, der_len);
OPENSSL_free(der);
EC_KEY_free(eckey);
}
struct dpp_signed_connector_info {
unsigned char *payload;
size_t payload_len;
};
static int
dpp_process_signed_connector(struct dpp_signed_connector_info *info,
EVP_PKEY *csign_pub, const char *connector)
{
int ret = -1;
const char *pos, *end, *signed_start, *signed_end;
struct wpabuf *kid = NULL;
unsigned char *prot_hdr = NULL, *signature = NULL;
size_t prot_hdr_len = 0, signature_len = 0;
const EVP_MD *sign_md = NULL;
unsigned char *der = NULL;
int der_len;
int res;
EVP_MD_CTX *md_ctx = NULL;
ECDSA_SIG *sig = NULL;
BIGNUM *r = NULL, *s = NULL;
const struct dpp_curve_params *curve;
EC_KEY *eckey;
const EC_GROUP *group;
int nid;
eckey = EVP_PKEY_get1_EC_KEY(csign_pub);
if (!eckey)
goto fail;
group = EC_KEY_get0_group(eckey);
if (!group)
goto fail;
nid = EC_GROUP_get_curve_name(group);
curve = dpp_get_curve_nid(nid);
if (!curve)
goto fail;
wpa_printf(MSG_DEBUG, "DPP: C-sign-key group: %s", curve->jwk_crv);
os_memset(info, 0, sizeof(*info));
signed_start = pos = connector;
end = os_strchr(pos, '.');
if (!end) {
wpa_printf(MSG_DEBUG, "DPP: Missing dot(1) in signedConnector");
goto fail;
}
prot_hdr = base64_url_decode((const unsigned char *) pos,
end - pos, &prot_hdr_len);
if (!prot_hdr) {
wpa_printf(MSG_DEBUG,
"DPP: Failed to base64url decode signedConnector JWS Protected Header");
goto fail;
}
wpa_hexdump_ascii(MSG_DEBUG,
"DPP: signedConnector - JWS Protected Header",
prot_hdr, prot_hdr_len);
kid = dpp_parse_jws_prot_hdr(curve, prot_hdr, prot_hdr_len, &sign_md);
if (!kid)
goto fail;
if (wpabuf_len(kid) != SHA256_MAC_LEN) {
wpa_printf(MSG_DEBUG,
"DPP: Unexpected signedConnector JWS Protected Header kid length: %u (expected %u)",
(unsigned int) wpabuf_len(kid), SHA256_MAC_LEN);
goto fail;
}
pos = end + 1;
end = os_strchr(pos, '.');
if (!end) {
wpa_printf(MSG_DEBUG,
"DPP: Missing dot(2) in signedConnector");
goto fail;
}
signed_end = end - 1;
info->payload = base64_url_decode((const unsigned char *) pos,
end - pos, &info->payload_len);
if (!info->payload) {
wpa_printf(MSG_DEBUG,
"DPP: Failed to base64url decode signedConnector JWS Payload");
goto fail;
}
wpa_hexdump_ascii(MSG_DEBUG,
"DPP: signedConnector - JWS Payload",
info->payload, info->payload_len);
pos = end + 1;
signature = base64_url_decode((const unsigned char *) pos,
os_strlen(pos), &signature_len);
if (!signature) {
wpa_printf(MSG_DEBUG,
"DPP: Failed to base64url decode signedConnector signature");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: signedConnector - signature",
signature, signature_len);
if (dpp_check_pubkey_match(csign_pub, kid) < 0)
goto fail;
if (signature_len & 0x01) {
wpa_printf(MSG_DEBUG,
"DPP: Unexpected signedConnector signature length (%d)",
(int) signature_len);
goto fail;
}
/* JWS Signature encodes the signature (r,s) as two octet strings. Need
* to convert that to DER encoded ECDSA_SIG for OpenSSL EVP routines. */
r = BN_bin2bn(signature, signature_len / 2, NULL);
s = BN_bin2bn(signature + signature_len / 2, signature_len / 2, NULL);
sig = ECDSA_SIG_new();
if (!r || !s || !sig || ECDSA_SIG_set0(sig, r, s) != 1)
goto fail;
r = NULL;
s = NULL;
der_len = i2d_ECDSA_SIG(sig, &der);
if (der_len <= 0) {
wpa_printf(MSG_DEBUG, "DPP: Could not DER encode signature");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: DER encoded signature", der, der_len);
md_ctx = EVP_MD_CTX_create();
if (!md_ctx)
goto fail;
ERR_clear_error();
if (EVP_DigestVerifyInit(md_ctx, NULL, sign_md, NULL, csign_pub) != 1) {
wpa_printf(MSG_DEBUG, "DPP: EVP_DigestVerifyInit failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
if (EVP_DigestVerifyUpdate(md_ctx, signed_start,
signed_end - signed_start + 1) != 1) {
wpa_printf(MSG_DEBUG, "DPP: EVP_DigestVerifyUpdate failed: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
res = EVP_DigestVerifyFinal(md_ctx, der, der_len);
if (res != 1) {
wpa_printf(MSG_DEBUG,
"DPP: EVP_DigestVerifyFinal failed (res=%d): %s",
res, ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
ret = 0;
fail:
EC_KEY_free(eckey);
EVP_MD_CTX_destroy(md_ctx);
os_free(prot_hdr);
wpabuf_free(kid);
os_free(signature);
ECDSA_SIG_free(sig);
BN_free(r);
BN_free(s);
OPENSSL_free(der);
return ret;
}
static int dpp_parse_cred_dpp(struct dpp_authentication *auth,
struct json_token *cred)
{
struct dpp_signed_connector_info info;
struct json_token *token, *csign;
int ret = -1;
EVP_PKEY *csign_pub = NULL;
const struct dpp_curve_params *key_curve = NULL;
const char *signed_connector;
os_memset(&info, 0, sizeof(info));
wpa_printf(MSG_DEBUG, "DPP: Connector credential");
csign = json_get_member(cred, "csign");
if (!csign || csign->type != JSON_OBJECT) {
wpa_printf(MSG_DEBUG, "DPP: No csign JWK in JSON");
goto fail;
}
csign_pub = dpp_parse_jwk(csign, &key_curve);
if (!csign_pub) {
wpa_printf(MSG_DEBUG, "DPP: Failed to parse csign JWK");
goto fail;
}
dpp_debug_print_key("DPP: Received C-sign-key", csign_pub);
token = json_get_member(cred, "signedConnector");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No signedConnector string found");
goto fail;
}
wpa_hexdump_ascii(MSG_DEBUG, "DPP: signedConnector",
token->string, os_strlen(token->string));
signed_connector = token->string;
if (os_strchr(signed_connector, '"') ||
os_strchr(signed_connector, '\n')) {
wpa_printf(MSG_DEBUG,
"DPP: Unexpected character in signedConnector");
goto fail;
}
if (dpp_process_signed_connector(&info, csign_pub,
signed_connector) < 0)
goto fail;
if (dpp_parse_connector(auth, info.payload, info.payload_len) < 0) {
wpa_printf(MSG_DEBUG, "DPP: Failed to parse connector");
goto fail;
}
os_free(auth->connector);
auth->connector = os_strdup(signed_connector);
dpp_copy_csign(auth, csign_pub);
dpp_copy_netaccesskey(auth);
ret = 0;
fail:
EVP_PKEY_free(csign_pub);
os_free(info.payload);
return ret;
}
static int dpp_parse_conf_obj(struct dpp_authentication *auth,
const u8 *conf_obj, u16 conf_obj_len)
{
int ret = -1;
struct json_token *root, *token, *discovery, *cred;
root = json_parse((const char *) conf_obj, conf_obj_len);
if (!root)
return -1;
if (root->type != JSON_OBJECT) {
wpa_printf(MSG_DEBUG, "DPP: JSON root is not an object");
goto fail;
}
token = json_get_member(root, "wi-fi_tech");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG, "DPP: No wi-fi_tech string value found");
goto fail;
}
if (os_strcmp(token->string, "infra") != 0) {
wpa_printf(MSG_DEBUG, "DPP: Unsupported wi-fi_tech value: '%s'",
token->string);
goto fail;
}
discovery = json_get_member(root, "discovery");
if (!discovery || discovery->type != JSON_OBJECT) {
wpa_printf(MSG_DEBUG, "DPP: No discovery object in JSON");
goto fail;
}
token = json_get_member(discovery, "ssid");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG,
"DPP: No discovery::ssid string value found");
goto fail;
}
wpa_hexdump_ascii(MSG_DEBUG, "DPP: discovery::ssid",
token->string, os_strlen(token->string));
if (os_strlen(token->string) > SSID_MAX_LEN) {
wpa_printf(MSG_DEBUG,
"DPP: Too long discovery::ssid string value");
goto fail;
}
auth->ssid_len = os_strlen(token->string);
os_memcpy(auth->ssid, token->string, auth->ssid_len);
cred = json_get_member(root, "cred");
if (!cred || cred->type != JSON_OBJECT) {
wpa_printf(MSG_DEBUG, "DPP: No cred object in JSON");
goto fail;
}
token = json_get_member(cred, "akm");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG,
"DPP: No cred::akm string value found");
goto fail;
}
if (os_strcmp(token->string, "psk") == 0) {
if (dpp_parse_cred_legacy(auth, cred) < 0)
goto fail;
} else if (os_strcmp(token->string, "dpp") == 0) {
if (dpp_parse_cred_dpp(auth, cred) < 0)
goto fail;
} else {
wpa_printf(MSG_DEBUG, "DPP: Unsupported akm: %s",
token->string);
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: JSON parsing completed successfully");
ret = 0;
fail:
json_free(root);
return ret;
}
int dpp_conf_resp_rx(struct dpp_authentication *auth,
const struct wpabuf *resp)
{
const u8 *wrapped_data, *e_nonce, *status, *conf_obj;
u16 wrapped_data_len, e_nonce_len, status_len, conf_obj_len;
const u8 *addr[1];
size_t len[1];
u8 *unwrapped = NULL;
size_t unwrapped_len = 0;
int ret = -1;
if (dpp_check_attrs(wpabuf_head(resp), wpabuf_len(resp)) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in config response");
return -1;
}
wrapped_data = dpp_get_attr(wpabuf_head(resp), wpabuf_len(resp),
DPP_ATTR_WRAPPED_DATA,
&wrapped_data_len);
if (!wrapped_data || wrapped_data_len < AES_BLOCK_SIZE) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required Wrapped data attribute");
return -1;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, wrapped_data_len);
unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
unwrapped = os_malloc(unwrapped_len);
if (!unwrapped)
return -1;
addr[0] = wpabuf_head(resp);
len[0] = wrapped_data - 4 - (const u8 *) wpabuf_head(resp);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD", addr[0], len[0]);
if (aes_siv_decrypt(auth->ke, auth->curve->hash_len,
wrapped_data, wrapped_data_len,
1, addr, len, unwrapped) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped, unwrapped_len);
if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in unwrapped data");
goto fail;
}
e_nonce = dpp_get_attr(unwrapped, unwrapped_len,
DPP_ATTR_ENROLLEE_NONCE,
&e_nonce_len);
if (!e_nonce || e_nonce_len != auth->curve->nonce_len) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid Enrollee Nonce attribute");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: Enrollee Nonce", e_nonce, e_nonce_len);
if (os_memcmp(e_nonce, auth->e_nonce, e_nonce_len) != 0) {
wpa_printf(MSG_DEBUG, "Enrollee Nonce mismatch");
goto fail;
}
status = dpp_get_attr(wpabuf_head(resp), wpabuf_len(resp),
DPP_ATTR_STATUS, &status_len);
if (!status || status_len < 1) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required DPP Status attribute");
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: Status %u", status[0]);
if (status[0] != DPP_STATUS_OK) {
wpa_printf(MSG_DEBUG, "DPP: Configuration failed");
goto fail;
}
conf_obj = dpp_get_attr(unwrapped, unwrapped_len,
DPP_ATTR_CONFIG_OBJ, &conf_obj_len);
if (!conf_obj) {
wpa_printf(MSG_DEBUG,
"DPP: Missing required Configuration Object attribute");
goto fail;
}
wpa_hexdump_ascii(MSG_DEBUG, "DPP: configurationObject JSON",
conf_obj, conf_obj_len);
if (dpp_parse_conf_obj(auth, conf_obj, conf_obj_len) < 0)
goto fail;
ret = 0;
fail:
os_free(unwrapped);
return ret;
}
void dpp_configurator_free(struct dpp_configurator *conf)
{
if (!conf)
return;
EVP_PKEY_free(conf->csign);
os_free(conf->kid);
os_free(conf);
}
struct dpp_configurator *
dpp_keygen_configurator(const char *curve, const u8 *privkey,
size_t privkey_len)
{
struct dpp_configurator *conf;
struct wpabuf *csign_pub = NULL;
u8 kid_hash[SHA256_MAC_LEN];
const u8 *addr[1];
size_t len[1];
conf = os_zalloc(sizeof(*conf));
if (!conf)
return NULL;
if (!curve) {
conf->curve = &dpp_curves[0];
} else {
conf->curve = dpp_get_curve_name(curve);
if (!conf->curve) {
wpa_printf(MSG_INFO, "DPP: Unsupported curve: %s",
curve);
return NULL;
}
}
if (privkey)
conf->csign = dpp_set_keypair(&conf->curve, privkey,
privkey_len);
else
conf->csign = dpp_gen_keypair(conf->curve);
if (!conf->csign)
goto fail;
conf->own = 1;
csign_pub = dpp_get_pubkey_point(conf->csign, 1);
if (!csign_pub) {
wpa_printf(MSG_INFO, "DPP: Failed to extract C-sign-key");
goto fail;
}
/* kid = SHA256(ANSI X9.63 uncompressed C-sign-key) */
addr[0] = wpabuf_head(csign_pub);
len[0] = wpabuf_len(csign_pub);
if (sha256_vector(1, addr, len, kid_hash) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Failed to derive kid for C-sign-key");
goto fail;
}
conf->kid = (char *) base64_url_encode(kid_hash, sizeof(kid_hash),
NULL, 0);
if (!conf->kid)
goto fail;
out:
wpabuf_free(csign_pub);
return conf;
fail:
dpp_configurator_free(conf);
conf = NULL;
goto out;
}
int dpp_configurator_own_config(struct dpp_authentication *auth,
const char *curve)
{
struct wpabuf *conf_obj;
int ret = -1;
if (!auth->conf) {
wpa_printf(MSG_DEBUG, "DPP: No configurator specified");
return -1;
}
if (!curve) {
auth->curve = &dpp_curves[0];
} else {
auth->curve = dpp_get_curve_name(curve);
if (!auth->curve) {
wpa_printf(MSG_INFO, "DPP: Unsupported curve: %s",
curve);
return -1;
}
}
wpa_printf(MSG_DEBUG,
"DPP: Building own configuration/connector with curve %s",
auth->curve->name);
auth->own_protocol_key = dpp_gen_keypair(auth->curve);
if (!auth->own_protocol_key)
return -1;
dpp_copy_netaccesskey(auth);
auth->peer_protocol_key = auth->own_protocol_key;
dpp_copy_csign(auth, auth->conf->csign);
conf_obj = dpp_build_conf_obj(auth, 0);
if (!conf_obj)
goto fail;
ret = dpp_parse_conf_obj(auth, wpabuf_head(conf_obj),
wpabuf_len(conf_obj));
fail:
wpabuf_free(conf_obj);
auth->peer_protocol_key = NULL;
return ret;
}
static int dpp_compatible_netrole(const char *role1, const char *role2)
{
return (os_strcmp(role1, "sta") == 0 && os_strcmp(role2, "ap") == 0) ||
(os_strcmp(role1, "ap") == 0 && os_strcmp(role2, "sta") == 0);
}
static int dpp_connector_compatible_group(struct json_token *root,
const char *group_id,
const char *net_role)
{
struct json_token *groups, *token;
groups = json_get_member(root, "groups");
if (!groups || groups->type != JSON_ARRAY)
return 0;
for (token = groups->child; token; token = token->sibling) {
struct json_token *id, *role;
id = json_get_member(token, "groupId");
if (!id || id->type != JSON_STRING)
continue;
role = json_get_member(token, "netRole");
if (!role || role->type != JSON_STRING)
continue;
if (os_strcmp(id->string, "*") != 0 &&
os_strcmp(group_id, "*") != 0 &&
os_strcmp(id->string, group_id) != 0)
continue;
if (dpp_compatible_netrole(role->string, net_role))
return 1;
}
return 0;
}
static int dpp_connector_match_groups(struct json_token *own_root,
struct json_token *peer_root)
{
struct json_token *groups, *token;
groups = json_get_member(peer_root, "groups");
if (!groups || groups->type != JSON_ARRAY) {
wpa_printf(MSG_DEBUG, "DPP: No peer groups array found");
return 0;
}
for (token = groups->child; token; token = token->sibling) {
struct json_token *id, *role;
id = json_get_member(token, "groupId");
if (!id || id->type != JSON_STRING) {
wpa_printf(MSG_DEBUG,
"DPP: Missing peer groupId string");
continue;
}
role = json_get_member(token, "netRole");
if (!role || role->type != JSON_STRING) {
wpa_printf(MSG_DEBUG,
"DPP: Missing peer groups::netRole string");
continue;
}
wpa_printf(MSG_DEBUG,
"DPP: peer connector group: groupId='%s' netRole='%s'",
id->string, role->string);
if (dpp_connector_compatible_group(own_root, id->string,
role->string)) {
wpa_printf(MSG_DEBUG,
"DPP: Compatible group/netRole in own connector");
return 1;
}
}
return 0;
}
static int dpp_derive_pmk(const u8 *Nx, size_t Nx_len, u8 *pmk,
unsigned int hash_len)
{
u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN];
const char *info = "DPP PMK";
int res;
/* PMK = HKDF(<>, "DPP PMK", N.x) */
/* HKDF-Extract(<>, N.x) */
os_memset(salt, 0, hash_len);
if (dpp_hmac(hash_len, salt, hash_len, Nx, Nx_len, prk) < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM=N.x)",
prk, hash_len);
/* HKDF-Expand(PRK, info, L) */
res = dpp_hkdf_expand(hash_len, prk, hash_len, info, pmk, hash_len);
os_memset(prk, 0, hash_len);
if (res < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: PMK = HKDF-Expand(PRK, info, L)",
pmk, hash_len);
return 0;
}
static int dpp_derive_pmkid(const struct dpp_curve_params *curve,
EVP_PKEY *own_key, EVP_PKEY *peer_key, u8 *pmkid)
{
struct wpabuf *nkx, *pkx;
int ret = -1, res;
const u8 *addr[2];
size_t len[2];
u8 hash[SHA256_MAC_LEN];
/* PMKID = Truncate-128(H(min(NK.x, PK.x) | max(NK.x, PK.x))) */
nkx = dpp_get_pubkey_point(own_key, 0);
pkx = dpp_get_pubkey_point(peer_key, 0);
if (!nkx || !pkx)
goto fail;
addr[0] = wpabuf_head(nkx);
len[0] = wpabuf_len(nkx) / 2;
addr[1] = wpabuf_head(pkx);
len[1] = wpabuf_len(pkx) / 2;
if (len[0] != len[1])
goto fail;
if (os_memcmp(addr[0], addr[1], len[0]) > 0) {
addr[0] = wpabuf_head(pkx);
addr[1] = wpabuf_head(nkx);
}
wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash payload 1", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash payload 2", addr[1], len[1]);
res = sha256_vector(2, addr, len, hash);
if (res < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash output", hash, SHA256_MAC_LEN);
os_memcpy(pmkid, hash, PMKID_LEN);
wpa_hexdump(MSG_DEBUG, "DPP: PMKID", pmkid, PMKID_LEN);
ret = 0;
fail:
wpabuf_free(nkx);
wpabuf_free(pkx);
return ret;
}
int dpp_peer_intro(struct dpp_introduction *intro, const char *own_connector,
const u8 *net_access_key, size_t net_access_key_len,
const u8 *csign_key, size_t csign_key_len,
const u8 *peer_connector, size_t peer_connector_len,
os_time_t *expiry)
{
struct json_token *root = NULL, *netkey, *token;
struct json_token *own_root = NULL;
int ret = -1;
EVP_PKEY *own_key = NULL, *peer_key = NULL;
struct wpabuf *own_key_pub = NULL;
const struct dpp_curve_params *curve, *own_curve;
struct dpp_signed_connector_info info;
const unsigned char *p;
EVP_PKEY *csign = NULL;
char *signed_connector = NULL;
const char *pos, *end;
unsigned char *own_conn = NULL;
size_t own_conn_len;
EVP_PKEY_CTX *ctx = NULL;
size_t Nx_len;
u8 Nx[DPP_MAX_SHARED_SECRET_LEN];
os_memset(intro, 0, sizeof(*intro));
os_memset(&info, 0, sizeof(info));
if (expiry)
*expiry = 0;
p = csign_key;
csign = d2i_PUBKEY(NULL, &p, csign_key_len);
if (!csign) {
wpa_printf(MSG_ERROR,
"DPP: Failed to parse local C-sign-key information");
goto fail;
}
own_key = dpp_set_keypair(&own_curve, net_access_key,
net_access_key_len);
if (!own_key) {
wpa_printf(MSG_ERROR, "DPP: Failed to parse own netAccessKey");
goto fail;
}
pos = os_strchr(own_connector, '.');
if (!pos) {
wpa_printf(MSG_DEBUG, "DPP: Own connector is missing the first dot (.)");
goto fail;
}
pos++;
end = os_strchr(pos, '.');
if (!end) {
wpa_printf(MSG_DEBUG, "DPP: Own connector is missing the second dot (.)");
goto fail;
}
own_conn = base64_url_decode((const unsigned char *) pos,
end - pos, &own_conn_len);
if (!own_conn) {
wpa_printf(MSG_DEBUG,
"DPP: Failed to base64url decode own signedConnector JWS Payload");
goto fail;
}
own_root = json_parse((const char *) own_conn, own_conn_len);
if (!own_root) {
wpa_printf(MSG_DEBUG, "DPP: Failed to parse local connector");
goto fail;
}
wpa_hexdump_ascii(MSG_DEBUG, "DPP: Peer signedConnector",
peer_connector, peer_connector_len);
signed_connector = os_malloc(peer_connector_len + 1);
if (!signed_connector)
goto fail;
os_memcpy(signed_connector, peer_connector, peer_connector_len);
signed_connector[peer_connector_len] = '\0';
if (dpp_process_signed_connector(&info, csign, signed_connector) < 0)
goto fail;
root = json_parse((const char *) info.payload, info.payload_len);
if (!root) {
wpa_printf(MSG_DEBUG, "DPP: JSON parsing of connector failed");
goto fail;
}
if (!dpp_connector_match_groups(own_root, root)) {
wpa_printf(MSG_DEBUG,
"DPP: Peer connector does not include compatible group netrole with own connector");
goto fail;
}
token = json_get_member(root, "expiry");
if (!token || token->type != JSON_STRING) {
wpa_printf(MSG_DEBUG,
"DPP: No expiry string found - connector does not expire");
} else {
wpa_printf(MSG_DEBUG, "DPP: expiry = %s", token->string);
if (dpp_key_expired(token->string, expiry)) {
wpa_printf(MSG_DEBUG,
"DPP: Connector (netAccessKey) has expired");
goto fail;
}
}
netkey = json_get_member(root, "netAccessKey");
if (!netkey || netkey->type != JSON_OBJECT) {
wpa_printf(MSG_DEBUG, "DPP: No netAccessKey object found");
goto fail;
}
peer_key = dpp_parse_jwk(netkey, &curve);
if (!peer_key)
goto fail;
dpp_debug_print_key("DPP: Received netAccessKey", peer_key);
if (own_curve != curve) {
wpa_printf(MSG_DEBUG,
"DPP: Mismatching netAccessKey curves (%s != %s)",
own_curve->name, curve->name);
goto fail;
}
/* ECDH: N = nk * PK */
ctx = EVP_PKEY_CTX_new(own_key, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, peer_key) != 1 ||
EVP_PKEY_derive(ctx, NULL, &Nx_len) != 1 ||
Nx_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, Nx, &Nx_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (N.x)",
Nx, Nx_len);
/* PMK = HKDF(<>, "DPP PMK", N.x) */
if (dpp_derive_pmk(Nx, Nx_len, intro->pmk, curve->hash_len) < 0) {
wpa_printf(MSG_ERROR, "DPP: Failed to derive PMK");
goto fail;
}
intro->pmk_len = curve->hash_len;
/* PMKID = Truncate-128(H(min(NK.x, PK.x) | max(NK.x, PK.x))) */
if (dpp_derive_pmkid(curve, own_key, peer_key, intro->pmkid) < 0) {
wpa_printf(MSG_ERROR, "DPP: Failed to derive PMKID");
goto fail;
}
ret = 0;
fail:
if (ret < 0)
os_memset(intro, 0, sizeof(*intro));
os_memset(Nx, 0, sizeof(Nx));
EVP_PKEY_CTX_free(ctx);
os_free(own_conn);
os_free(signed_connector);
os_free(info.payload);
EVP_PKEY_free(own_key);
wpabuf_free(own_key_pub);
EVP_PKEY_free(peer_key);
EVP_PKEY_free(csign);
json_free(root);
json_free(own_root);
return ret;
}
static EVP_PKEY * dpp_pkex_get_role_elem(const struct dpp_curve_params *curve,
int init)
{
EC_GROUP *group;
size_t len = curve->prime_len;
const u8 *x, *y;
switch (curve->ike_group) {
case 19:
x = init ? pkex_init_x_p256 : pkex_resp_x_p256;
y = init ? pkex_init_y_p256 : pkex_resp_y_p256;
break;
case 20:
x = init ? pkex_init_x_p384 : pkex_resp_x_p384;
y = init ? pkex_init_y_p384 : pkex_resp_y_p384;
break;
case 21:
x = init ? pkex_init_x_p521 : pkex_resp_x_p521;
y = init ? pkex_init_y_p521 : pkex_resp_y_p521;
break;
case 28:
x = init ? pkex_init_x_bp_p256r1 : pkex_resp_x_bp_p256r1;
y = init ? pkex_init_y_bp_p256r1 : pkex_resp_y_bp_p256r1;
break;
case 29:
x = init ? pkex_init_x_bp_p384r1 : pkex_resp_x_bp_p384r1;
y = init ? pkex_init_y_bp_p384r1 : pkex_resp_y_bp_p384r1;
break;
case 30:
x = init ? pkex_init_x_bp_p512r1 : pkex_resp_x_bp_p512r1;
y = init ? pkex_init_y_bp_p512r1 : pkex_resp_y_bp_p512r1;
break;
default:
return NULL;
}
group = EC_GROUP_new_by_curve_name(OBJ_txt2nid(curve->name));
if (!group)
return NULL;
return dpp_set_pubkey_point_group(group, x, y, len);
}
static EC_POINT * dpp_pkex_derive_Qi(const struct dpp_curve_params *curve,
const u8 *mac_init, const char *code,
const char *identifier, BN_CTX *bnctx,
const EC_GROUP **ret_group)
{
u8 hash[DPP_MAX_HASH_LEN];
const u8 *addr[3];
size_t len[3];
unsigned int num_elem = 0;
EC_POINT *Qi = NULL;
EVP_PKEY *Pi = NULL;
EC_KEY *Pi_ec = NULL;
const EC_POINT *Pi_point;
BIGNUM *hash_bn = NULL;
const EC_GROUP *group = NULL;
EC_GROUP *group2 = NULL;
/* Qi = H(MAC-Initiator | [identifier |] code) * Pi */
wpa_printf(MSG_DEBUG, "DPP: MAC-Initiator: " MACSTR, MAC2STR(mac_init));
addr[num_elem] = mac_init;
len[num_elem] = ETH_ALEN;
num_elem++;
if (identifier) {
wpa_printf(MSG_DEBUG, "DPP: code identifier: %s",
identifier);
addr[num_elem] = (const u8 *) identifier;
len[num_elem] = os_strlen(identifier);
num_elem++;
}
wpa_hexdump_ascii_key(MSG_DEBUG, "DPP: code", code, os_strlen(code));
addr[num_elem] = (const u8 *) code;
len[num_elem] = os_strlen(code);
num_elem++;
if (dpp_hash_vector(curve, num_elem, addr, len, hash) < 0)
goto fail;
wpa_hexdump_key(MSG_DEBUG,
"DPP: H(MAC-Initiator | [identifier |] code)",
hash, curve->hash_len);
Pi = dpp_pkex_get_role_elem(curve, 1);
if (!Pi)
goto fail;
dpp_debug_print_key("DPP: Pi", Pi);
Pi_ec = EVP_PKEY_get1_EC_KEY(Pi);
if (!Pi_ec)
goto fail;
Pi_point = EC_KEY_get0_public_key(Pi_ec);
group = EC_KEY_get0_group(Pi_ec);
if (!group)
goto fail;
group2 = EC_GROUP_dup(group);
if (!group2)
goto fail;
Qi = EC_POINT_new(group2);
if (!Qi) {
EC_GROUP_free(group2);
goto fail;
}
hash_bn = BN_bin2bn(hash, curve->hash_len, NULL);
if (!hash_bn ||
EC_POINT_mul(group2, Qi, NULL, Pi_point, hash_bn, bnctx) != 1)
goto fail;
if (EC_POINT_is_at_infinity(group, Qi)) {
wpa_printf(MSG_INFO, "PDP: Qi is the point-at-infinity");
goto fail;
}
out:
EC_KEY_free(Pi_ec);
EVP_PKEY_free(Pi);
BN_clear_free(hash_bn);
if (ret_group)
*ret_group = group2;
return Qi;
fail:
EC_POINT_free(Qi);
Qi = NULL;
goto out;
}
static EC_POINT * dpp_pkex_derive_Qr(const struct dpp_curve_params *curve,
const u8 *mac_resp, const char *code,
const char *identifier, BN_CTX *bnctx,
const EC_GROUP **ret_group)
{
u8 hash[DPP_MAX_HASH_LEN];
const u8 *addr[3];
size_t len[3];
unsigned int num_elem = 0;
EC_POINT *Qr = NULL;
EVP_PKEY *Pr = NULL;
EC_KEY *Pr_ec = NULL;
const EC_POINT *Pr_point;
BIGNUM *hash_bn = NULL;
const EC_GROUP *group = NULL;
EC_GROUP *group2 = NULL;
/* Qr = H(MAC-Responder | | [identifier | ] code) * Pr */
wpa_printf(MSG_DEBUG, "DPP: MAC-Responder: " MACSTR, MAC2STR(mac_resp));
addr[num_elem] = mac_resp;
len[num_elem] = ETH_ALEN;
num_elem++;
if (identifier) {
wpa_printf(MSG_DEBUG, "DPP: code identifier: %s",
identifier);
addr[num_elem] = (const u8 *) identifier;
len[num_elem] = os_strlen(identifier);
num_elem++;
}
wpa_hexdump_ascii_key(MSG_DEBUG, "DPP: code", code, os_strlen(code));
addr[num_elem] = (const u8 *) code;
len[num_elem] = os_strlen(code);
num_elem++;
if (dpp_hash_vector(curve, num_elem, addr, len, hash) < 0)
goto fail;
wpa_hexdump_key(MSG_DEBUG,
"DPP: H(MAC-Responder | [identifier |] code)",
hash, curve->hash_len);
Pr = dpp_pkex_get_role_elem(curve, 0);
if (!Pr)
goto fail;
dpp_debug_print_key("DPP: Pr", Pr);
Pr_ec = EVP_PKEY_get1_EC_KEY(Pr);
if (!Pr_ec)
goto fail;
Pr_point = EC_KEY_get0_public_key(Pr_ec);
group = EC_KEY_get0_group(Pr_ec);
if (!group)
goto fail;
group2 = EC_GROUP_dup(group);
if (!group2)
goto fail;
Qr = EC_POINT_new(group2);
if (!Qr) {
EC_GROUP_free(group2);
goto fail;
}
hash_bn = BN_bin2bn(hash, curve->hash_len, NULL);
if (!hash_bn ||
EC_POINT_mul(group2, Qr, NULL, Pr_point, hash_bn, bnctx) != 1)
goto fail;
out:
EC_KEY_free(Pr_ec);
EVP_PKEY_free(Pr);
BN_clear_free(hash_bn);
if (ret_group)
*ret_group = group2;
return Qr;
fail:
EC_POINT_free(Qr);
Qr = NULL;
goto out;
}
static struct wpabuf * dpp_pkex_build_exchange_req(struct dpp_pkex *pkex)
{
EC_KEY *X_ec = NULL;
const EC_POINT *X_point;
BN_CTX *bnctx = NULL;
const EC_GROUP *group;
EC_POINT *Qi = NULL, *M = NULL;
struct wpabuf *M_buf = NULL;
BIGNUM *Mx = NULL, *My = NULL;
struct wpabuf *msg = NULL;
size_t attr_len;
const struct dpp_curve_params *curve = pkex->own_bi->curve;
int num_bytes, offset;
wpa_printf(MSG_DEBUG, "DPP: Build PKEX Exchange Request");
/* Qi = H(MAC-Initiator | [identifier |] code) * Pi */
bnctx = BN_CTX_new();
if (!bnctx)
goto fail;
Qi = dpp_pkex_derive_Qi(curve, pkex->own_mac, pkex->code,
pkex->identifier, bnctx, &group);
if (!Qi)
goto fail;
/* Generate a random ephemeral keypair x/X */
pkex->x = dpp_gen_keypair(curve);
if (!pkex->x)
goto fail;
/* M = X + Qi */
X_ec = EVP_PKEY_get1_EC_KEY(pkex->x);
if (!X_ec)
goto fail;
X_point = EC_KEY_get0_public_key(X_ec);
if (!X_point)
goto fail;
M = EC_POINT_new(group);
Mx = BN_new();
My = BN_new();
if (!M || !Mx || !My ||
EC_POINT_add(group, M, X_point, Qi, bnctx) != 1 ||
EC_POINT_get_affine_coordinates_GFp(group, M, Mx, My, bnctx) != 1)
goto fail;
/* Initiator -> Responder: group, [identifier,] M */
attr_len = 4 + 2;
if (pkex->identifier)
attr_len += 4 + os_strlen(pkex->identifier);
attr_len += 4 + 2 * curve->prime_len;
msg = dpp_alloc_msg(DPP_PA_PKEX_EXCHANGE_REQ, attr_len);
if (!msg)
goto fail;
/* Finite Cyclic Group attribute */
wpabuf_put_le16(msg, DPP_ATTR_FINITE_CYCLIC_GROUP);
wpabuf_put_le16(msg, 2);
wpabuf_put_le16(msg, curve->ike_group);
/* Code Identifier attribute */
if (pkex->identifier) {
wpabuf_put_le16(msg, DPP_ATTR_CODE_IDENTIFIER);
wpabuf_put_le16(msg, os_strlen(pkex->identifier));
wpabuf_put_str(msg, pkex->identifier);
}
/* M in Encrypted Key attribute */
wpabuf_put_le16(msg, DPP_ATTR_ENCRYPTED_KEY);
wpabuf_put_le16(msg, 2 * curve->prime_len);
num_bytes = BN_num_bytes(Mx);
if ((size_t) num_bytes > curve->prime_len)
goto fail;
if (curve->prime_len > (size_t) num_bytes)
offset = curve->prime_len - num_bytes;
else
offset = 0;
os_memset(wpabuf_put(msg, offset), 0, offset);
BN_bn2bin(Mx, wpabuf_put(msg, num_bytes));
os_memset(pkex->Mx, 0, offset);
BN_bn2bin(Mx, pkex->Mx + offset);
num_bytes = BN_num_bytes(My);
if ((size_t) num_bytes > curve->prime_len)
goto fail;
if (curve->prime_len > (size_t) num_bytes)
offset = curve->prime_len - num_bytes;
else
offset = 0;
os_memset(wpabuf_put(msg, offset), 0, offset);
BN_bn2bin(My, wpabuf_put(msg, num_bytes));
out:
wpabuf_free(M_buf);
EC_KEY_free(X_ec);
EC_POINT_free(M);
EC_POINT_free(Qi);
BN_clear_free(Mx);
BN_clear_free(My);
BN_CTX_free(bnctx);
return msg;
fail:
wpa_printf(MSG_INFO, "DPP: Failed to build PKEX Exchange Request");
wpabuf_free(msg);
msg = NULL;
goto out;
}
struct dpp_pkex * dpp_pkex_init(struct dpp_bootstrap_info *bi,
const u8 *own_mac,
const char *identifier,
const char *code)
{
struct dpp_pkex *pkex;
pkex = os_zalloc(sizeof(*pkex));
if (!pkex)
return NULL;
pkex->initiator = 1;
pkex->own_bi = bi;
os_memcpy(pkex->own_mac, own_mac, ETH_ALEN);
if (identifier) {
pkex->identifier = os_strdup(identifier);
if (!pkex->identifier)
goto fail;
}
pkex->code = os_strdup(code);
if (!pkex->code)
goto fail;
pkex->exchange_req = dpp_pkex_build_exchange_req(pkex);
if (!pkex->exchange_req)
goto fail;
return pkex;
fail:
dpp_pkex_free(pkex);
return NULL;
}
struct dpp_pkex * dpp_pkex_rx_exchange_req(struct dpp_bootstrap_info *bi,
const u8 *own_mac,
const u8 *peer_mac,
const char *identifier,
const char *code,
const u8 *buf, size_t len)
{
const u8 *attr_group, *attr_id, *attr_key;
u16 attr_group_len, attr_id_len, attr_key_len;
const struct dpp_curve_params *curve = bi->curve;
u16 ike_group;
struct dpp_pkex *pkex = NULL;
EC_POINT *Qi = NULL, *Qr = NULL, *M = NULL, *X = NULL, *N = NULL;
BN_CTX *bnctx = NULL;
const EC_GROUP *group;
BIGNUM *Mx = NULL, *My = NULL;
EC_KEY *Y_ec = NULL, *X_ec = NULL;;
const EC_POINT *Y_point;
BIGNUM *Nx = NULL, *Ny = NULL;
struct wpabuf *msg = NULL;
size_t attr_len;
int num_bytes, offset;
attr_id = dpp_get_attr(buf, len, DPP_ATTR_CODE_IDENTIFIER,
&attr_id_len);
if (!attr_id && identifier) {
wpa_printf(MSG_DEBUG,
"DPP: No PKEX code identifier received, but expected one");
return NULL;
}
if (attr_id && identifier &&
(os_strlen(identifier) != attr_id_len ||
os_memcmp(identifier, attr_id, attr_id_len) != 0)) {
wpa_printf(MSG_DEBUG, "DPP: PKEX code identifier mismatch");
return NULL;
}
attr_group = dpp_get_attr(buf, len, DPP_ATTR_FINITE_CYCLIC_GROUP,
&attr_group_len);
if (!attr_group || attr_group_len != 2) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid Finite Cyclic Group attribute");
return NULL;
}
ike_group = WPA_GET_LE16(attr_group);
if (ike_group != curve->ike_group) {
wpa_printf(MSG_DEBUG,
"DPP: Mismatching PKEX curve: peer=%u own=%u",
ike_group, curve->ike_group);
/* TODO: error response with suggested curve:
* DPP Status, group */
return NULL;
}
/* M in Encrypted Key attribute */
attr_key = dpp_get_attr(buf, len, DPP_ATTR_ENCRYPTED_KEY,
&attr_key_len);
if (!attr_key || attr_key_len & 0x01 || attr_key_len < 2 ||
attr_key_len / 2 > DPP_MAX_SHARED_SECRET_LEN) {
wpa_printf(MSG_DEBUG, "DPP: Missing Encrypted Key attribute");
return NULL;
}
/* Qi = H(MAC-Initiator | [identifier |] code) * Pi */
bnctx = BN_CTX_new();
if (!bnctx)
goto fail;
Qi = dpp_pkex_derive_Qi(curve, peer_mac, code, identifier, bnctx,
&group);
if (!Qi)
goto fail;
/* X' = M - Qi */
X = EC_POINT_new(group);
M = EC_POINT_new(group);
Mx = BN_bin2bn(attr_key, attr_key_len / 2, NULL);
My = BN_bin2bn(attr_key + attr_key_len / 2, attr_key_len / 2, NULL);
if (!X || !M || !Mx || !My ||
EC_POINT_set_affine_coordinates_GFp(group, M, Mx, My, bnctx) != 1 ||
EC_POINT_is_at_infinity(group, M) ||
!EC_POINT_is_on_curve(group, M, bnctx) ||
EC_POINT_invert(group, Qi, bnctx) != 1 ||
EC_POINT_add(group, X, M, Qi, bnctx) != 1 ||
EC_POINT_is_at_infinity(group, X) ||
!EC_POINT_is_on_curve(group, X, bnctx))
goto fail;
pkex = os_zalloc(sizeof(*pkex));
if (!pkex)
goto fail;
pkex->own_bi = bi;
os_memcpy(pkex->own_mac, own_mac, ETH_ALEN);
os_memcpy(pkex->peer_mac, peer_mac, ETH_ALEN);
if (identifier) {
pkex->identifier = os_strdup(identifier);
if (!pkex->identifier)
goto fail;
}
pkex->code = os_strdup(code);
if (!pkex->code)
goto fail;
os_memcpy(pkex->Mx, attr_key, attr_key_len / 2);
X_ec = EC_KEY_new();
if (!X_ec ||
EC_KEY_set_group(X_ec, group) != 1 ||
EC_KEY_set_public_key(X_ec, X) != 1)
goto fail;
pkex->x = EVP_PKEY_new();
if (!pkex->x ||
EVP_PKEY_set1_EC_KEY(pkex->x, X_ec) != 1)
goto fail;
/* Qr = H(MAC-Responder | | [identifier | ] code) * Pr */
Qr = dpp_pkex_derive_Qr(curve, own_mac, code, identifier, bnctx, NULL);
if (!Qr)
goto fail;
/* Generate a random ephemeral keypair y/Y */
pkex->y = dpp_gen_keypair(curve);
if (!pkex->y)
goto fail;
/* N = Y + Qr */
Y_ec = EVP_PKEY_get1_EC_KEY(pkex->y);
if (!Y_ec)
goto fail;
Y_point = EC_KEY_get0_public_key(Y_ec);
if (!Y_point)
goto fail;
N = EC_POINT_new(group);
Nx = BN_new();
Ny = BN_new();
if (!N || !Nx || !Ny ||
EC_POINT_add(group, N, Y_point, Qr, bnctx) != 1 ||
EC_POINT_get_affine_coordinates_GFp(group, N, Nx, Ny, bnctx) != 1)
goto fail;
/* Initiator -> Responder: DPP Status, [identifier,] N */
attr_len = 4 + 1;
if (identifier)
attr_len += 4 + os_strlen(identifier);
attr_len += 4 + 2 * curve->prime_len;
msg = dpp_alloc_msg(DPP_PA_PKEX_EXCHANGE_RESP, attr_len);
if (!msg)
goto fail;
/* DPP Status */
wpabuf_put_le16(msg, DPP_ATTR_STATUS);
wpabuf_put_le16(msg, 1);
wpabuf_put_u8(msg, DPP_STATUS_OK);
/* Code Identifier attribute */
if (pkex->identifier) {
wpabuf_put_le16(msg, DPP_ATTR_CODE_IDENTIFIER);
wpabuf_put_le16(msg, os_strlen(pkex->identifier));
wpabuf_put_str(msg, pkex->identifier);
}
/* N in Encrypted Key attribute */
wpabuf_put_le16(msg, DPP_ATTR_ENCRYPTED_KEY);
wpabuf_put_le16(msg, 2 * curve->prime_len);
num_bytes = BN_num_bytes(Nx);
if ((size_t) num_bytes > curve->prime_len)
goto fail;
if (curve->prime_len > (size_t) num_bytes)
offset = curve->prime_len - num_bytes;
else
offset = 0;
os_memset(wpabuf_put(msg, offset), 0, offset);
BN_bn2bin(Nx, wpabuf_put(msg, num_bytes));
os_memset(pkex->Nx, 0, offset);
BN_bn2bin(Nx, pkex->Nx + offset);
num_bytes = BN_num_bytes(Ny);
if ((size_t) num_bytes > curve->prime_len)
goto fail;
if (curve->prime_len > (size_t) num_bytes)
offset = curve->prime_len - num_bytes;
else
offset = 0;
os_memset(wpabuf_put(msg, offset), 0, offset);
BN_bn2bin(Ny, wpabuf_put(msg, num_bytes));
pkex->exchange_resp = msg;
msg = NULL;
pkex->exchange_done = 1;
out:
wpabuf_free(msg);
BN_CTX_free(bnctx);
EC_POINT_free(Qi);
EC_POINT_free(Qr);
BN_free(Mx);
BN_free(My);
BN_free(Nx);
BN_free(Ny);
EC_POINT_free(M);
EC_POINT_free(N);
EC_POINT_free(X);
EC_KEY_free(X_ec);
EC_KEY_free(Y_ec);
return pkex;
fail:
wpa_printf(MSG_DEBUG, "DPP: PKEX Exchange Request processing faileed");
dpp_pkex_free(pkex);
pkex = NULL;
goto out;
}
static int dpp_pkex_derive_z(const u8 *mac_init, const u8 *mac_resp,
const u8 *Mx, size_t Mx_len,
const u8 *Nx, size_t Nx_len,
const char *code,
const u8 *Kx, size_t Kx_len,
u8 *z, unsigned int hash_len)
{
u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN];
int res;
u8 *info, *pos;
size_t info_len;
/* z = HKDF(<>, MAC-Initiator | MAC-Responder | M.x | N.x | code, K.x)
*/
/* HKDF-Extract(<>, IKM=K.x) */
os_memset(salt, 0, hash_len);
if (dpp_hmac(hash_len, salt, hash_len, Kx, Kx_len, prk) < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM)",
prk, hash_len);
info_len = 2 * ETH_ALEN + Mx_len + Nx_len + os_strlen(code);
info = os_malloc(info_len);
if (!info)
return -1;
pos = info;
os_memcpy(pos, mac_init, ETH_ALEN);
pos += ETH_ALEN;
os_memcpy(pos, mac_resp, ETH_ALEN);
pos += ETH_ALEN;
os_memcpy(pos, Mx, Mx_len);
pos += Mx_len;
os_memcpy(pos, Nx, Nx_len);
pos += Nx_len;
os_memcpy(pos, code, os_strlen(code));
/* HKDF-Expand(PRK, info, L) */
if (hash_len == 32)
res = hmac_sha256_kdf(prk, hash_len, NULL, info, info_len,
z, hash_len);
else if (hash_len == 48)
res = hmac_sha384_kdf(prk, hash_len, NULL, info, info_len,
z, hash_len);
else if (hash_len == 64)
res = hmac_sha512_kdf(prk, hash_len, NULL, info, info_len,
z, hash_len);
else
res = -1;
os_free(info);
os_memset(prk, 0, hash_len);
if (res < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "DPP: z = HKDF-Expand(PRK, info, L)",
z, hash_len);
return 0;
}
struct wpabuf * dpp_pkex_rx_exchange_resp(struct dpp_pkex *pkex,
const u8 *buf, size_t buflen)
{
const u8 *attr_status, *attr_id, *attr_key;
u16 attr_status_len, attr_id_len, attr_key_len;
const EC_GROUP *group;
BN_CTX *bnctx = NULL;
size_t clear_len;
struct wpabuf *clear = NULL;
u8 *wrapped;
struct wpabuf *msg = NULL, *A_pub = NULL, *X_pub = NULL, *Y_pub = NULL;
const struct dpp_curve_params *curve = pkex->own_bi->curve;
EC_POINT *Qr = NULL, *Y = NULL, *N = NULL;
BIGNUM *Nx = NULL, *Ny = NULL;
EVP_PKEY_CTX *ctx = NULL;
EC_KEY *Y_ec = NULL;
size_t Jx_len, Kx_len;
u8 Jx[DPP_MAX_SHARED_SECRET_LEN], Kx[DPP_MAX_SHARED_SECRET_LEN];
const u8 *addr[4];
size_t len[4];
u8 u[DPP_MAX_HASH_LEN];
u8 octet;
int res;
attr_status = dpp_get_attr(buf, buflen, DPP_ATTR_STATUS,
&attr_status_len);
if (!attr_status || attr_status_len != 1) {
wpa_printf(MSG_DEBUG, "DPP: No DPP Status attribute");
return NULL;
}
wpa_printf(MSG_DEBUG, "DPP: Status %u", attr_status[0]);
if (attr_status[0] != DPP_STATUS_OK) {
wpa_printf(MSG_DEBUG, "DPP: PKEX failed");
return NULL;
}
attr_id = dpp_get_attr(buf, buflen, DPP_ATTR_CODE_IDENTIFIER,
&attr_id_len);
if (!attr_id && pkex->identifier) {
wpa_printf(MSG_DEBUG,
"DPP: No PKEX code identifier received, but expected one");
return NULL;
}
if (attr_id && pkex->identifier &&
(os_strlen(pkex->identifier) != attr_id_len ||
os_memcmp(pkex->identifier, attr_id, attr_id_len) != 0)) {
wpa_printf(MSG_DEBUG, "DPP: PKEX code identifier mismatch");
return NULL;
}
/* N in Encrypted Key attribute */
attr_key = dpp_get_attr(buf, buflen, DPP_ATTR_ENCRYPTED_KEY,
&attr_key_len);
if (!attr_key || attr_key_len & 0x01 || attr_key_len < 2) {
wpa_printf(MSG_DEBUG, "DPP: Missing Encrypted Key attribute");
return NULL;
}
/* Qr = H(MAC-Responder | [identifier |] code) * Pr */
bnctx = BN_CTX_new();
if (!bnctx)
goto fail;
Qr = dpp_pkex_derive_Qr(curve, pkex->peer_mac, pkex->code,
pkex->identifier, bnctx, &group);
if (!Qr)
goto fail;
/* Y' = N - Qr */
Y = EC_POINT_new(group);
N = EC_POINT_new(group);
Nx = BN_bin2bn(attr_key, attr_key_len / 2, NULL);
Ny = BN_bin2bn(attr_key + attr_key_len / 2, attr_key_len / 2, NULL);
if (!Y || !N || !Nx || !Ny ||
EC_POINT_set_affine_coordinates_GFp(group, N, Nx, Ny, bnctx) != 1 ||
EC_POINT_is_at_infinity(group, N) ||
!EC_POINT_is_on_curve(group, N, bnctx) ||
EC_POINT_invert(group, Qr, bnctx) != 1 ||
EC_POINT_add(group, Y, N, Qr, bnctx) != 1 ||
EC_POINT_is_at_infinity(group, Y) ||
!EC_POINT_is_on_curve(group, Y, bnctx))
goto fail;
pkex->exchange_done = 1;
/* ECDH: J = a * Y’ */
Y_ec = EC_KEY_new();
if (!Y_ec ||
EC_KEY_set_group(Y_ec, group) != 1 ||
EC_KEY_set_public_key(Y_ec, Y) != 1)
goto fail;
pkex->y = EVP_PKEY_new();
if (!pkex->y ||
EVP_PKEY_set1_EC_KEY(pkex->y, Y_ec) != 1)
goto fail;
ctx = EVP_PKEY_CTX_new(pkex->own_bi->pubkey, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, pkex->y) != 1 ||
EVP_PKEY_derive(ctx, NULL, &Jx_len) != 1 ||
Jx_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, Jx, &Jx_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (J.x)",
Jx, Jx_len);
/* u = HMAC(J.x, MAC-Initiator | A.x | Y’.x | X.x ) */
A_pub = dpp_get_pubkey_point(pkex->own_bi->pubkey, 0);
Y_pub = dpp_get_pubkey_point(pkex->y, 0);
X_pub = dpp_get_pubkey_point(pkex->x, 0);
if (!A_pub || !Y_pub || !X_pub)
goto fail;
addr[0] = pkex->own_mac;
len[0] = ETH_ALEN;
addr[1] = wpabuf_head(A_pub);
len[1] = wpabuf_len(A_pub) / 2;
addr[2] = wpabuf_head(Y_pub);
len[2] = wpabuf_len(Y_pub) / 2;
addr[3] = wpabuf_head(X_pub);
len[3] = wpabuf_len(X_pub) / 2;
if (dpp_hmac_vector(curve->hash_len, Jx, Jx_len, 4, addr, len, u) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: u", u, curve->hash_len);
/* K = x * Y’ */
EVP_PKEY_CTX_free(ctx);
ctx = EVP_PKEY_CTX_new(pkex->x, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, pkex->y) != 1 ||
EVP_PKEY_derive(ctx, NULL, &Kx_len) != 1 ||
Kx_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, Kx, &Kx_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (K.x)",
Kx, Kx_len);
/* z = HKDF(<>, MAC-Initiator | MAC-Responder | M.x | N.x | code, K.x)
*/
res = dpp_pkex_derive_z(pkex->own_mac, pkex->peer_mac,
pkex->Mx, curve->prime_len,
attr_key /* N.x */, attr_key_len / 2,
pkex->code, Kx, Kx_len,
pkex->z, curve->hash_len);
os_memset(Kx, 0, Kx_len);
if (res < 0)
goto fail;
/* {A, u, [bootstrapping info]}z */
clear_len = 4 + 2 * curve->prime_len + 4 + curve->hash_len;
clear = wpabuf_alloc(clear_len);
msg = dpp_alloc_msg(DPP_PA_PKEX_COMMIT_REVEAL_REQ,
4 + clear_len + AES_BLOCK_SIZE);
if (!clear || !msg)
goto fail;
/* A in Bootstrap Key attribute */
wpabuf_put_le16(clear, DPP_ATTR_BOOTSTRAP_KEY);
wpabuf_put_le16(clear, wpabuf_len(A_pub));
wpabuf_put_buf(clear, A_pub);
/* u in I-Auth tag attribute */
wpabuf_put_le16(clear, DPP_ATTR_I_AUTH_TAG);
wpabuf_put_le16(clear, curve->hash_len);
wpabuf_put_data(clear, u, curve->hash_len);
addr[0] = wpabuf_head_u8(msg) + 2;
len[0] = DPP_HDR_LEN;
octet = 0;
addr[1] = &octet;
len[1] = sizeof(octet);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
wpabuf_put_le16(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
wrapped = wpabuf_put(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
wpa_hexdump_buf(MSG_DEBUG, "DPP: AES-SIV cleartext", clear);
if (aes_siv_encrypt(pkex->z, curve->hash_len,
wpabuf_head(clear), wpabuf_len(clear),
2, addr, len, wrapped) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped, wpabuf_len(clear) + AES_BLOCK_SIZE);
out:
wpabuf_free(clear);
wpabuf_free(A_pub);
wpabuf_free(X_pub);
wpabuf_free(Y_pub);
EC_POINT_free(Qr);
EC_POINT_free(Y);
EC_POINT_free(N);
BN_free(Nx);
BN_free(Ny);
EC_KEY_free(Y_ec);
EVP_PKEY_CTX_free(ctx);
BN_CTX_free(bnctx);
return msg;
fail:
wpa_printf(MSG_DEBUG, "DPP: PKEX Exchange Response processing faileed");
wpabuf_free(msg);
msg = NULL;
goto out;
}
struct wpabuf * dpp_pkex_rx_commit_reveal_req(struct dpp_pkex *pkex,
const u8 *hdr,
const u8 *buf, size_t buflen)
{
const struct dpp_curve_params *curve = pkex->own_bi->curve;
EVP_PKEY_CTX *ctx;
size_t Jx_len, Kx_len, Lx_len;
u8 Jx[DPP_MAX_SHARED_SECRET_LEN], Kx[DPP_MAX_SHARED_SECRET_LEN];
u8 Lx[DPP_MAX_SHARED_SECRET_LEN];
const u8 *wrapped_data, *b_key, *peer_u;
u16 wrapped_data_len, b_key_len, peer_u_len = 0;
const u8 *addr[4];
size_t len[4];
u8 octet;
u8 *unwrapped = NULL;
size_t unwrapped_len = 0;
struct wpabuf *msg = NULL, *A_pub = NULL, *X_pub = NULL, *Y_pub = NULL;
struct wpabuf *B_pub = NULL;
u8 u[DPP_MAX_HASH_LEN], v[DPP_MAX_HASH_LEN];
size_t clear_len;
struct wpabuf *clear = NULL;
u8 *wrapped;
int res;
/* K = y * X' */
ctx = EVP_PKEY_CTX_new(pkex->y, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, pkex->x) != 1 ||
EVP_PKEY_derive(ctx, NULL, &Kx_len) != 1 ||
Kx_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, Kx, &Kx_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (K.x)",
Kx, Kx_len);
/* z = HKDF(<>, MAC-Initiator | MAC-Responder | M.x | N.x | code, K.x)
*/
res = dpp_pkex_derive_z(pkex->peer_mac, pkex->own_mac,
pkex->Mx, curve->prime_len,
pkex->Nx, curve->prime_len, pkex->code,
Kx, Kx_len, pkex->z, curve->hash_len);
os_memset(Kx, 0, Kx_len);
if (res < 0)
goto fail;
wrapped_data = dpp_get_attr(buf, buflen, DPP_ATTR_WRAPPED_DATA,
&wrapped_data_len);
if (!wrapped_data || wrapped_data_len < AES_BLOCK_SIZE) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required Wrapped data attribute");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, wrapped_data_len);
unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
unwrapped = os_malloc(unwrapped_len);
if (!unwrapped)
goto fail;
addr[0] = hdr;
len[0] = DPP_HDR_LEN;
octet = 0;
addr[1] = &octet;
len[1] = sizeof(octet);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
if (aes_siv_decrypt(pkex->z, curve->hash_len,
wrapped_data, wrapped_data_len,
2, addr, len, unwrapped) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped, unwrapped_len);
if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in unwrapped data");
goto fail;
}
b_key = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_BOOTSTRAP_KEY,
&b_key_len);
if (!b_key || b_key_len != 2 * curve->prime_len) {
wpa_printf(MSG_DEBUG,
"DPP: No valid peer bootstrapping key found");
goto fail;
}
pkex->peer_bootstrap_key = dpp_set_pubkey_point(pkex->x, b_key,
b_key_len);
if (!pkex->peer_bootstrap_key)
goto fail;
dpp_debug_print_key("DPP: Peer bootstrap public key",
pkex->peer_bootstrap_key);
/* ECDH: J' = y * A' */
EVP_PKEY_CTX_free(ctx);
ctx = EVP_PKEY_CTX_new(pkex->y, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, pkex->peer_bootstrap_key) != 1 ||
EVP_PKEY_derive(ctx, NULL, &Jx_len) != 1 ||
Jx_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, Jx, &Jx_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (J.x)",
Jx, Jx_len);
/* u' = HMAC(J'.x, MAC-Initiator | A'.x | Y.x | X'.x) */
A_pub = dpp_get_pubkey_point(pkex->peer_bootstrap_key, 0);
Y_pub = dpp_get_pubkey_point(pkex->y, 0);
X_pub = dpp_get_pubkey_point(pkex->x, 0);
if (!A_pub || !Y_pub || !X_pub)
goto fail;
addr[0] = pkex->peer_mac;
len[0] = ETH_ALEN;
addr[1] = wpabuf_head(A_pub);
len[1] = wpabuf_len(A_pub) / 2;
addr[2] = wpabuf_head(Y_pub);
len[2] = wpabuf_len(Y_pub) / 2;
addr[3] = wpabuf_head(X_pub);
len[3] = wpabuf_len(X_pub) / 2;
if (dpp_hmac_vector(curve->hash_len, Jx, Jx_len, 4, addr, len, u) < 0)
goto fail;
peer_u = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_I_AUTH_TAG,
&peer_u_len);
if (!peer_u || peer_u_len != curve->hash_len ||
os_memcmp(peer_u, u, curve->hash_len) != 0) {
wpa_printf(MSG_DEBUG, "DPP: No valid u (I-Auth tag) found");
wpa_hexdump(MSG_DEBUG, "DPP: Calculated u'",
u, curve->hash_len);
wpa_hexdump(MSG_DEBUG, "DPP: Received u", peer_u, peer_u_len);
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: Valid u (I-Auth tag) received");
/* ECDH: L = b * X' */
EVP_PKEY_CTX_free(ctx);
ctx = EVP_PKEY_CTX_new(pkex->own_bi->pubkey, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, pkex->x) != 1 ||
EVP_PKEY_derive(ctx, NULL, &Lx_len) != 1 ||
Lx_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, Lx, &Lx_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (L.x)",
Lx, Lx_len);
/* v = HMAC(L.x, MAC-Responder | B.x | X'.x | Y.x) */
B_pub = dpp_get_pubkey_point(pkex->own_bi->pubkey, 0);
if (!B_pub)
goto fail;
addr[0] = pkex->own_mac;
len[0] = ETH_ALEN;
addr[1] = wpabuf_head(B_pub);
len[1] = wpabuf_len(B_pub) / 2;
addr[2] = wpabuf_head(X_pub);
len[2] = wpabuf_len(X_pub) / 2;
addr[3] = wpabuf_head(Y_pub);
len[3] = wpabuf_len(Y_pub) / 2;
if (dpp_hmac_vector(curve->hash_len, Lx, Lx_len, 4, addr, len, v) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: v", v, curve->hash_len);
/* {B, v [bootstrapping info]}z */
clear_len = 4 + 2 * curve->prime_len + 4 + curve->hash_len;
clear = wpabuf_alloc(clear_len);
msg = dpp_alloc_msg(DPP_PA_PKEX_COMMIT_REVEAL_RESP,
4 + clear_len + AES_BLOCK_SIZE);
if (!clear || !msg)
goto fail;
/* A in Bootstrap Key attribute */
wpabuf_put_le16(clear, DPP_ATTR_BOOTSTRAP_KEY);
wpabuf_put_le16(clear, wpabuf_len(B_pub));
wpabuf_put_buf(clear, B_pub);
/* v in R-Auth tag attribute */
wpabuf_put_le16(clear, DPP_ATTR_R_AUTH_TAG);
wpabuf_put_le16(clear, curve->hash_len);
wpabuf_put_data(clear, v, curve->hash_len);
addr[0] = wpabuf_head_u8(msg) + 2;
len[0] = DPP_HDR_LEN;
octet = 1;
addr[1] = &octet;
len[1] = sizeof(octet);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
wpabuf_put_le16(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
wrapped = wpabuf_put(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
wpa_hexdump_buf(MSG_DEBUG, "DPP: AES-SIV cleartext", clear);
if (aes_siv_encrypt(pkex->z, curve->hash_len,
wpabuf_head(clear), wpabuf_len(clear),
2, addr, len, wrapped) < 0)
goto fail;
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped, wpabuf_len(clear) + AES_BLOCK_SIZE);
out:
EVP_PKEY_CTX_free(ctx);
os_free(unwrapped);
wpabuf_free(A_pub);
wpabuf_free(B_pub);
wpabuf_free(X_pub);
wpabuf_free(Y_pub);
wpabuf_free(clear);
return msg;
fail:
wpabuf_free(msg);
msg = NULL;
goto out;
}
int dpp_pkex_rx_commit_reveal_resp(struct dpp_pkex *pkex, const u8 *hdr,
const u8 *buf, size_t buflen)
{
const struct dpp_curve_params *curve = pkex->own_bi->curve;
const u8 *wrapped_data, *b_key, *peer_v;
u16 wrapped_data_len, b_key_len, peer_v_len = 0;
const u8 *addr[4];
size_t len[4];
u8 octet;
u8 *unwrapped = NULL;
size_t unwrapped_len = 0;
int ret = -1;
u8 v[DPP_MAX_HASH_LEN];
size_t Lx_len;
u8 Lx[DPP_MAX_SHARED_SECRET_LEN];
EVP_PKEY_CTX *ctx = NULL;
struct wpabuf *B_pub = NULL, *X_pub = NULL, *Y_pub = NULL;
wrapped_data = dpp_get_attr(buf, buflen, DPP_ATTR_WRAPPED_DATA,
&wrapped_data_len);
if (!wrapped_data || wrapped_data_len < AES_BLOCK_SIZE) {
wpa_printf(MSG_DEBUG,
"DPP: Missing or invalid required Wrapped data attribute");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
wrapped_data, wrapped_data_len);
unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
unwrapped = os_malloc(unwrapped_len);
if (!unwrapped)
goto fail;
addr[0] = hdr;
len[0] = DPP_HDR_LEN;
octet = 1;
addr[1] = &octet;
len[1] = sizeof(octet);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
if (aes_siv_decrypt(pkex->z, curve->hash_len,
wrapped_data, wrapped_data_len,
2, addr, len, unwrapped) < 0) {
wpa_printf(MSG_DEBUG, "DPP: AES-SIV decryption failed");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
unwrapped, unwrapped_len);
if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
wpa_printf(MSG_DEBUG,
"DPP: Invalid attribute in unwrapped data");
goto fail;
}
b_key = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_BOOTSTRAP_KEY,
&b_key_len);
if (!b_key || b_key_len != 2 * curve->prime_len) {
wpa_printf(MSG_DEBUG,
"DPP: No valid peer bootstrapping key found");
goto fail;
}
pkex->peer_bootstrap_key = dpp_set_pubkey_point(pkex->x, b_key,
b_key_len);
if (!pkex->peer_bootstrap_key)
goto fail;
dpp_debug_print_key("DPP: Peer bootstrap public key",
pkex->peer_bootstrap_key);
/* ECDH: L' = x * B' */
ctx = EVP_PKEY_CTX_new(pkex->x, NULL);
if (!ctx ||
EVP_PKEY_derive_init(ctx) != 1 ||
EVP_PKEY_derive_set_peer(ctx, pkex->peer_bootstrap_key) != 1 ||
EVP_PKEY_derive(ctx, NULL, &Lx_len) != 1 ||
Lx_len > DPP_MAX_SHARED_SECRET_LEN ||
EVP_PKEY_derive(ctx, Lx, &Lx_len) != 1) {
wpa_printf(MSG_ERROR,
"DPP: Failed to derive ECDH shared secret: %s",
ERR_error_string(ERR_get_error(), NULL));
goto fail;
}
wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (L.x)",
Lx, Lx_len);
/* v' = HMAC(L.x, MAC-Responder | B'.x | X.x | Y'.x) */
B_pub = dpp_get_pubkey_point(pkex->peer_bootstrap_key, 0);
X_pub = dpp_get_pubkey_point(pkex->x, 0);
Y_pub = dpp_get_pubkey_point(pkex->y, 0);
if (!B_pub || !X_pub || !Y_pub)
goto fail;
addr[0] = pkex->peer_mac;
len[0] = ETH_ALEN;
addr[1] = wpabuf_head(B_pub);
len[1] = wpabuf_len(B_pub) / 2;
addr[2] = wpabuf_head(X_pub);
len[2] = wpabuf_len(X_pub) / 2;
addr[3] = wpabuf_head(Y_pub);
len[3] = wpabuf_len(Y_pub) / 2;
if (dpp_hmac_vector(curve->hash_len, Lx, Lx_len, 4, addr, len, v) < 0)
goto fail;
peer_v = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_R_AUTH_TAG,
&peer_v_len);
if (!peer_v || peer_v_len != curve->hash_len ||
os_memcmp(peer_v, v, curve->hash_len) != 0) {
wpa_printf(MSG_DEBUG, "DPP: No valid v (R-Auth tag) found");
wpa_hexdump(MSG_DEBUG, "DPP: Calculated v'",
v, curve->hash_len);
wpa_hexdump(MSG_DEBUG, "DPP: Received v", peer_v, peer_v_len);
goto fail;
}
wpa_printf(MSG_DEBUG, "DPP: Valid v (R-Auth tag) received");
ret = 0;
out:
wpabuf_free(B_pub);
wpabuf_free(X_pub);
wpabuf_free(Y_pub);
EVP_PKEY_CTX_free(ctx);
os_free(unwrapped);
return ret;
fail:
goto out;
}
void dpp_pkex_free(struct dpp_pkex *pkex)
{
if (!pkex)
return;
os_free(pkex->identifier);
os_free(pkex->code);
EVP_PKEY_free(pkex->x);
EVP_PKEY_free(pkex->y);
EVP_PKEY_free(pkex->peer_bootstrap_key);
wpabuf_free(pkex->exchange_req);
wpabuf_free(pkex->exchange_resp);
os_free(pkex);
}