/*
* WPA Supplicant / Crypto wrapper for LibTomCrypt (for internal TLSv1)
* Copyright (c) 2005-2006, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include <tomcrypt.h>
#include "common.h"
#include "crypto.h"
#ifndef mp_init_multi
#define mp_init_multi ltc_init_multi
#define mp_clear_multi ltc_deinit_multi
#define mp_unsigned_bin_size(a) ltc_mp.unsigned_size(a)
#define mp_to_unsigned_bin(a, b) ltc_mp.unsigned_write(a, b)
#define mp_read_unsigned_bin(a, b, c) ltc_mp.unsigned_read(a, b, c)
#define mp_exptmod(a,b,c,d) ltc_mp.exptmod(a,b,c,d)
#endif
int md4_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
{
hash_state md;
size_t i;
md4_init(&md);
for (i = 0; i < num_elem; i++)
md4_process(&md, addr[i], len[i]);
md4_done(&md, mac);
return 0;
}
int des_encrypt(const u8 *clear, const u8 *key, u8 *cypher)
{
u8 pkey[8], next, tmp;
int i;
symmetric_key skey;
/* Add parity bits to the key */
next = 0;
for (i = 0; i < 7; i++) {
tmp = key[i];
pkey[i] = (tmp >> i) | next | 1;
next = tmp << (7 - i);
}
pkey[i] = next | 1;
des_setup(pkey, 8, 0, &skey);
des_ecb_encrypt(clear, cypher, &skey);
des_done(&skey);
return 0;
}
int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
{
hash_state md;
size_t i;
md5_init(&md);
for (i = 0; i < num_elem; i++)
md5_process(&md, addr[i], len[i]);
md5_done(&md, mac);
return 0;
}
int sha1_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
{
hash_state md;
size_t i;
sha1_init(&md);
for (i = 0; i < num_elem; i++)
sha1_process(&md, addr[i], len[i]);
sha1_done(&md, mac);
return 0;
}
void * aes_encrypt_init(const u8 *key, size_t len)
{
symmetric_key *skey;
skey = os_malloc(sizeof(*skey));
if (skey == NULL)
return NULL;
if (aes_setup(key, len, 0, skey) != CRYPT_OK) {
os_free(skey);
return NULL;
}
return skey;
}
int aes_encrypt(void *ctx, const u8 *plain, u8 *crypt)
{
symmetric_key *skey = ctx;
return aes_ecb_encrypt(plain, crypt, skey) == CRYPT_OK ? 0 : -1;
}
void aes_encrypt_deinit(void *ctx)
{
symmetric_key *skey = ctx;
aes_done(skey);
os_free(skey);
}
void * aes_decrypt_init(const u8 *key, size_t len)
{
symmetric_key *skey;
skey = os_malloc(sizeof(*skey));
if (skey == NULL)
return NULL;
if (aes_setup(key, len, 0, skey) != CRYPT_OK) {
os_free(skey);
return NULL;
}
return skey;
}
int aes_decrypt(void *ctx, const u8 *crypt, u8 *plain)
{
symmetric_key *skey = ctx;
return aes_ecb_encrypt(plain, (u8 *) crypt, skey) == CRYPT_OK ? 0 : -1;
}
void aes_decrypt_deinit(void *ctx)
{
symmetric_key *skey = ctx;
aes_done(skey);
os_free(skey);
}
struct crypto_hash {
enum crypto_hash_alg alg;
int error;
union {
hash_state md;
hmac_state hmac;
} u;
};
struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
size_t key_len)
{
struct crypto_hash *ctx;
ctx = os_zalloc(sizeof(*ctx));
if (ctx == NULL)
return NULL;
ctx->alg = alg;
switch (alg) {
case CRYPTO_HASH_ALG_MD5:
if (md5_init(&ctx->u.md) != CRYPT_OK)
goto fail;
break;
case CRYPTO_HASH_ALG_SHA1:
if (sha1_init(&ctx->u.md) != CRYPT_OK)
goto fail;
break;
case CRYPTO_HASH_ALG_HMAC_MD5:
if (hmac_init(&ctx->u.hmac, find_hash("md5"), key, key_len) !=
CRYPT_OK)
goto fail;
break;
case CRYPTO_HASH_ALG_HMAC_SHA1:
if (hmac_init(&ctx->u.hmac, find_hash("sha1"), key, key_len) !=
CRYPT_OK)
goto fail;
break;
default:
goto fail;
}
return ctx;
fail:
os_free(ctx);
return NULL;
}
void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len)
{
if (ctx == NULL || ctx->error)
return;
switch (ctx->alg) {
case CRYPTO_HASH_ALG_MD5:
ctx->error = md5_process(&ctx->u.md, data, len) != CRYPT_OK;
break;
case CRYPTO_HASH_ALG_SHA1:
ctx->error = sha1_process(&ctx->u.md, data, len) != CRYPT_OK;
break;
case CRYPTO_HASH_ALG_HMAC_MD5:
case CRYPTO_HASH_ALG_HMAC_SHA1:
ctx->error = hmac_process(&ctx->u.hmac, data, len) != CRYPT_OK;
break;
}
}
int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
{
int ret = 0;
unsigned long clen;
if (ctx == NULL)
return -2;
if (mac == NULL || len == NULL) {
os_free(ctx);
return 0;
}
if (ctx->error) {
os_free(ctx);
return -2;
}
switch (ctx->alg) {
case CRYPTO_HASH_ALG_MD5:
if (*len < 16) {
*len = 16;
os_free(ctx);
return -1;
}
*len = 16;
if (md5_done(&ctx->u.md, mac) != CRYPT_OK)
ret = -2;
break;
case CRYPTO_HASH_ALG_SHA1:
if (*len < 20) {
*len = 20;
os_free(ctx);
return -1;
}
*len = 20;
if (sha1_done(&ctx->u.md, mac) != CRYPT_OK)
ret = -2;
break;
case CRYPTO_HASH_ALG_HMAC_SHA1:
if (*len < 20) {
*len = 20;
os_free(ctx);
return -1;
}
/* continue */
case CRYPTO_HASH_ALG_HMAC_MD5:
if (*len < 16) {
*len = 16;
os_free(ctx);
return -1;
}
clen = *len;
if (hmac_done(&ctx->u.hmac, mac, &clen) != CRYPT_OK) {
os_free(ctx);
return -1;
}
*len = clen;
break;
default:
ret = -2;
break;
}
os_free(ctx);
if (TEST_FAIL())
return -1;
return ret;
}
struct crypto_cipher {
int rc4;
union {
symmetric_CBC cbc;
struct {
size_t used_bytes;
u8 key[16];
size_t keylen;
} rc4;
} u;
};
struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
const u8 *iv, const u8 *key,
size_t key_len)
{
struct crypto_cipher *ctx;
int idx, res, rc4 = 0;
switch (alg) {
case CRYPTO_CIPHER_ALG_AES:
idx = find_cipher("aes");
break;
case CRYPTO_CIPHER_ALG_3DES:
idx = find_cipher("3des");
break;
case CRYPTO_CIPHER_ALG_DES:
idx = find_cipher("des");
break;
case CRYPTO_CIPHER_ALG_RC2:
idx = find_cipher("rc2");
break;
case CRYPTO_CIPHER_ALG_RC4:
idx = -1;
rc4 = 1;
break;
default:
return NULL;
}
ctx = os_zalloc(sizeof(*ctx));
if (ctx == NULL)
return NULL;
if (rc4) {
ctx->rc4 = 1;
if (key_len > sizeof(ctx->u.rc4.key)) {
os_free(ctx);
return NULL;
}
ctx->u.rc4.keylen = key_len;
os_memcpy(ctx->u.rc4.key, key, key_len);
} else {
res = cbc_start(idx, iv, key, key_len, 0, &ctx->u.cbc);
if (res != CRYPT_OK) {
wpa_printf(MSG_DEBUG, "LibTomCrypt: Cipher start "
"failed: %s", error_to_string(res));
os_free(ctx);
return NULL;
}
}
return ctx;
}
int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
u8 *crypt, size_t len)
{
int res;
if (ctx->rc4) {
if (plain != crypt)
os_memcpy(crypt, plain, len);
rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
ctx->u.rc4.used_bytes, crypt, len);
ctx->u.rc4.used_bytes += len;
return 0;
}
res = cbc_encrypt(plain, crypt, len, &ctx->u.cbc);
if (res != CRYPT_OK) {
wpa_printf(MSG_DEBUG, "LibTomCrypt: CBC encryption "
"failed: %s", error_to_string(res));
return -1;
}
return 0;
}
int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
u8 *plain, size_t len)
{
int res;
if (ctx->rc4) {
if (plain != crypt)
os_memcpy(plain, crypt, len);
rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
ctx->u.rc4.used_bytes, plain, len);
ctx->u.rc4.used_bytes += len;
return 0;
}
res = cbc_decrypt(crypt, plain, len, &ctx->u.cbc);
if (res != CRYPT_OK) {
wpa_printf(MSG_DEBUG, "LibTomCrypt: CBC decryption "
"failed: %s", error_to_string(res));
return -1;
}
return 0;
}
void crypto_cipher_deinit(struct crypto_cipher *ctx)
{
if (!ctx->rc4)
cbc_done(&ctx->u.cbc);
os_free(ctx);
}
struct crypto_public_key {
rsa_key rsa;
};
struct crypto_private_key {
rsa_key rsa;
};
struct crypto_public_key * crypto_public_key_import(const u8 *key, size_t len)
{
int res;
struct crypto_public_key *pk;
pk = os_zalloc(sizeof(*pk));
if (pk == NULL)
return NULL;
res = rsa_import(key, len, &pk->rsa);
if (res != CRYPT_OK) {
wpa_printf(MSG_ERROR, "LibTomCrypt: Failed to import "
"public key (res=%d '%s')",
res, error_to_string(res));
os_free(pk);
return NULL;
}
if (pk->rsa.type != PK_PUBLIC) {
wpa_printf(MSG_ERROR, "LibTomCrypt: Public key was not of "
"correct type");
rsa_free(&pk->rsa);
os_free(pk);
return NULL;
}
return pk;
}
struct crypto_private_key * crypto_private_key_import(const u8 *key,
size_t len,
const char *passwd)
{
int res;
struct crypto_private_key *pk;
pk = os_zalloc(sizeof(*pk));
if (pk == NULL)
return NULL;
res = rsa_import(key, len, &pk->rsa);
if (res != CRYPT_OK) {
wpa_printf(MSG_ERROR, "LibTomCrypt: Failed to import "
"private key (res=%d '%s')",
res, error_to_string(res));
os_free(pk);
return NULL;
}
if (pk->rsa.type != PK_PRIVATE) {
wpa_printf(MSG_ERROR, "LibTomCrypt: Private key was not of "
"correct type");
rsa_free(&pk->rsa);
os_free(pk);
return NULL;
}
return pk;
}
struct crypto_public_key * crypto_public_key_from_cert(const u8 *buf,
size_t len)
{
/* No X.509 support in LibTomCrypt */
return NULL;
}
static int pkcs1_generate_encryption_block(u8 block_type, size_t modlen,
const u8 *in, size_t inlen,
u8 *out, size_t *outlen)
{
size_t ps_len;
u8 *pos;
/*
* PKCS #1 v1.5, 8.1:
*
* EB = 00 || BT || PS || 00 || D
* BT = 00 or 01 for private-key operation; 02 for public-key operation
* PS = k-3-||D||; at least eight octets
* (BT=0: PS=0x00, BT=1: PS=0xff, BT=2: PS=pseudorandom non-zero)
* k = length of modulus in octets (modlen)
*/
if (modlen < 12 || modlen > *outlen || inlen > modlen - 11) {
wpa_printf(MSG_DEBUG, "PKCS #1: %s - Invalid buffer "
"lengths (modlen=%lu outlen=%lu inlen=%lu)",
__func__, (unsigned long) modlen,
(unsigned long) *outlen,
(unsigned long) inlen);
return -1;
}
pos = out;
*pos++ = 0x00;
*pos++ = block_type; /* BT */
ps_len = modlen - inlen - 3;
switch (block_type) {
case 0:
os_memset(pos, 0x00, ps_len);
pos += ps_len;
break;
case 1:
os_memset(pos, 0xff, ps_len);
pos += ps_len;
break;
case 2:
if (os_get_random(pos, ps_len) < 0) {
wpa_printf(MSG_DEBUG, "PKCS #1: %s - Failed to get "
"random data for PS", __func__);
return -1;
}
while (ps_len--) {
if (*pos == 0x00)
*pos = 0x01;
pos++;
}
break;
default:
wpa_printf(MSG_DEBUG, "PKCS #1: %s - Unsupported block type "
"%d", __func__, block_type);
return -1;
}
*pos++ = 0x00;
os_memcpy(pos, in, inlen); /* D */
return 0;
}
static int crypto_rsa_encrypt_pkcs1(int block_type, rsa_key *key, int key_type,
const u8 *in, size_t inlen,
u8 *out, size_t *outlen)
{
unsigned long len, modlen;
int res;
modlen = mp_unsigned_bin_size(key->N);
if (pkcs1_generate_encryption_block(block_type, modlen, in, inlen,
out, outlen) < 0)
return -1;
len = *outlen;
res = rsa_exptmod(out, modlen, out, &len, key_type, key);
if (res != CRYPT_OK) {
wpa_printf(MSG_DEBUG, "LibTomCrypt: rsa_exptmod failed: %s",
error_to_string(res));
return -1;
}
*outlen = len;
return 0;
}
int crypto_public_key_encrypt_pkcs1_v15(struct crypto_public_key *key,
const u8 *in, size_t inlen,
u8 *out, size_t *outlen)
{
return crypto_rsa_encrypt_pkcs1(2, &key->rsa, PK_PUBLIC, in, inlen,
out, outlen);
}
int crypto_private_key_sign_pkcs1(struct crypto_private_key *key,
const u8 *in, size_t inlen,
u8 *out, size_t *outlen)
{
return crypto_rsa_encrypt_pkcs1(1, &key->rsa, PK_PRIVATE, in, inlen,
out, outlen);
}
void crypto_public_key_free(struct crypto_public_key *key)
{
if (key) {
rsa_free(&key->rsa);
os_free(key);
}
}
void crypto_private_key_free(struct crypto_private_key *key)
{
if (key) {
rsa_free(&key->rsa);
os_free(key);
}
}
int crypto_public_key_decrypt_pkcs1(struct crypto_public_key *key,
const u8 *crypt, size_t crypt_len,
u8 *plain, size_t *plain_len)
{
int res;
unsigned long len;
u8 *pos;
len = *plain_len;
res = rsa_exptmod(crypt, crypt_len, plain, &len, PK_PUBLIC,
&key->rsa);
if (res != CRYPT_OK) {
wpa_printf(MSG_DEBUG, "LibTomCrypt: rsa_exptmod failed: %s",
error_to_string(res));
return -1;
}
/*
* PKCS #1 v1.5, 8.1:
*
* EB = 00 || BT || PS || 00 || D
* BT = 01
* PS = k-3-||D|| times FF
* k = length of modulus in octets
*/
if (len < 3 + 8 + 16 /* min hash len */ ||
plain[0] != 0x00 || plain[1] != 0x01 || plain[2] != 0xff) {
wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
"structure");
return -1;
}
pos = plain + 3;
while (pos < plain + len && *pos == 0xff)
pos++;
if (pos - plain - 2 < 8) {
/* PKCS #1 v1.5, 8.1: At least eight octets long PS */
wpa_printf(MSG_INFO, "LibTomCrypt: Too short signature "
"padding");
return -1;
}
if (pos + 16 /* min hash len */ >= plain + len || *pos != 0x00) {
wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
"structure (2)");
return -1;
}
pos++;
len -= pos - plain;
/* Strip PKCS #1 header */
os_memmove(plain, pos, len);
*plain_len = len;
return 0;
}
int crypto_global_init(void)
{
ltc_mp = tfm_desc;
/* TODO: only register algorithms that are really needed */
if (register_hash(&md4_desc) < 0 ||
register_hash(&md5_desc) < 0 ||
register_hash(&sha1_desc) < 0 ||
register_cipher(&aes_desc) < 0 ||
register_cipher(&des_desc) < 0 ||
register_cipher(&des3_desc) < 0) {
wpa_printf(MSG_ERROR, "TLSv1: Failed to register "
"hash/cipher functions");
return -1;
}
return 0;
}
void crypto_global_deinit(void)
{
}
#ifdef CONFIG_MODEXP
int crypto_dh_init(u8 generator, const u8 *prime, size_t prime_len, u8 *privkey,
u8 *pubkey)
{
size_t pubkey_len, pad;
if (os_get_random(privkey, prime_len) < 0)
return -1;
if (os_memcmp(privkey, prime, prime_len) > 0) {
/* Make sure private value is smaller than prime */
privkey[0] = 0;
}
pubkey_len = prime_len;
if (crypto_mod_exp(&generator, 1, privkey, prime_len, prime, prime_len,
pubkey, &pubkey_len) < 0)
return -1;
if (pubkey_len < prime_len) {
pad = prime_len - pubkey_len;
os_memmove(pubkey + pad, pubkey, pubkey_len);
os_memset(pubkey, 0, pad);
}
return 0;
}
int crypto_dh_derive_secret(u8 generator, const u8 *prime, size_t prime_len,
const u8 *order, size_t order_len,
const u8 *privkey, size_t privkey_len,
const u8 *pubkey, size_t pubkey_len,
u8 *secret, size_t *len)
{
/* TODO: check pubkey */
return crypto_mod_exp(pubkey, pubkey_len, privkey, privkey_len,
prime, prime_len, secret, len);
}
int crypto_mod_exp(const u8 *base, size_t base_len,
const u8 *power, size_t power_len,
const u8 *modulus, size_t modulus_len,
u8 *result, size_t *result_len)
{
void *b, *p, *m, *r;
if (mp_init_multi(&b, &p, &m, &r, NULL) != CRYPT_OK)
return -1;
if (mp_read_unsigned_bin(b, (u8 *) base, base_len) != CRYPT_OK ||
mp_read_unsigned_bin(p, (u8 *) power, power_len) != CRYPT_OK ||
mp_read_unsigned_bin(m, (u8 *) modulus, modulus_len) != CRYPT_OK)
goto fail;
if (mp_exptmod(b, p, m, r) != CRYPT_OK)
goto fail;
*result_len = mp_unsigned_bin_size(r);
if (mp_to_unsigned_bin(r, result) != CRYPT_OK)
goto fail;
mp_clear_multi(b, p, m, r, NULL);
return 0;
fail:
mp_clear_multi(b, p, m, r, NULL);
return -1;
}
#endif /* CONFIG_MODEXP */