/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <openssl/rsa.h>
#include <limits.h>
#include <string.h>
#include <openssl/bn.h>
#include <openssl/engine.h>
#include <openssl/err.h>
#include <openssl/ex_data.h>
#include <openssl/mem.h>
#include <openssl/nid.h>
#include <openssl/thread.h>
#include "internal.h"
#include "../internal.h"
static CRYPTO_EX_DATA_CLASS g_ex_data_class = CRYPTO_EX_DATA_CLASS_INIT;
RSA *RSA_new(void) { return RSA_new_method(NULL); }
RSA *RSA_new_method(const ENGINE *engine) {
RSA *rsa = OPENSSL_malloc(sizeof(RSA));
if (rsa == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return NULL;
}
OPENSSL_memset(rsa, 0, sizeof(RSA));
if (engine) {
rsa->meth = ENGINE_get_RSA_method(engine);
}
if (rsa->meth == NULL) {
rsa->meth = (RSA_METHOD*) &RSA_default_method;
}
METHOD_ref(rsa->meth);
rsa->references = 1;
rsa->flags = rsa->meth->flags;
CRYPTO_MUTEX_init(&rsa->lock);
CRYPTO_new_ex_data(&rsa->ex_data);
if (rsa->meth->init && !rsa->meth->init(rsa)) {
CRYPTO_free_ex_data(&g_ex_data_class, rsa, &rsa->ex_data);
CRYPTO_MUTEX_cleanup(&rsa->lock);
METHOD_unref(rsa->meth);
OPENSSL_free(rsa);
return NULL;
}
return rsa;
}
void RSA_additional_prime_free(RSA_additional_prime *ap) {
if (ap == NULL) {
return;
}
BN_clear_free(ap->prime);
BN_clear_free(ap->exp);
BN_clear_free(ap->coeff);
BN_clear_free(ap->r);
BN_MONT_CTX_free(ap->mont);
OPENSSL_free(ap);
}
void RSA_free(RSA *rsa) {
unsigned u;
if (rsa == NULL) {
return;
}
if (!CRYPTO_refcount_dec_and_test_zero(&rsa->references)) {
return;
}
if (rsa->meth->finish) {
rsa->meth->finish(rsa);
}
METHOD_unref(rsa->meth);
CRYPTO_free_ex_data(&g_ex_data_class, rsa, &rsa->ex_data);
BN_clear_free(rsa->n);
BN_clear_free(rsa->e);
BN_clear_free(rsa->d);
BN_clear_free(rsa->p);
BN_clear_free(rsa->q);
BN_clear_free(rsa->dmp1);
BN_clear_free(rsa->dmq1);
BN_clear_free(rsa->iqmp);
BN_MONT_CTX_free(rsa->mont_n);
BN_MONT_CTX_free(rsa->mont_p);
BN_MONT_CTX_free(rsa->mont_q);
for (u = 0; u < rsa->num_blindings; u++) {
BN_BLINDING_free(rsa->blindings[u]);
}
OPENSSL_free(rsa->blindings);
OPENSSL_free(rsa->blindings_inuse);
if (rsa->additional_primes != NULL) {
sk_RSA_additional_prime_pop_free(rsa->additional_primes,
RSA_additional_prime_free);
}
CRYPTO_MUTEX_cleanup(&rsa->lock);
OPENSSL_free(rsa);
}
int RSA_up_ref(RSA *rsa) {
CRYPTO_refcount_inc(&rsa->references);
return 1;
}
void RSA_get0_key(const RSA *rsa, const BIGNUM **out_n, const BIGNUM **out_e,
const BIGNUM **out_d) {
if (out_n != NULL) {
*out_n = rsa->n;
}
if (out_e != NULL) {
*out_e = rsa->e;
}
if (out_d != NULL) {
*out_d = rsa->d;
}
}
void RSA_get0_factors(const RSA *rsa, const BIGNUM **out_p,
const BIGNUM **out_q) {
if (out_p != NULL) {
*out_p = rsa->p;
}
if (out_q != NULL) {
*out_q = rsa->q;
}
}
void RSA_get0_crt_params(const RSA *rsa, const BIGNUM **out_dmp1,
const BIGNUM **out_dmq1, const BIGNUM **out_iqmp) {
if (out_dmp1 != NULL) {
*out_dmp1 = rsa->dmp1;
}
if (out_dmq1 != NULL) {
*out_dmq1 = rsa->dmq1;
}
if (out_iqmp != NULL) {
*out_iqmp = rsa->iqmp;
}
}
int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) {
if (rsa->meth->keygen) {
return rsa->meth->keygen(rsa, bits, e_value, cb);
}
return rsa_default_keygen(rsa, bits, e_value, cb);
}
int RSA_generate_multi_prime_key(RSA *rsa, int bits, int num_primes,
BIGNUM *e_value, BN_GENCB *cb) {
if (rsa->meth->multi_prime_keygen) {
return rsa->meth->multi_prime_keygen(rsa, bits, num_primes, e_value, cb);
}
return rsa_default_multi_prime_keygen(rsa, bits, num_primes, e_value, cb);
}
int RSA_encrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
const uint8_t *in, size_t in_len, int padding) {
if (rsa->meth->encrypt) {
return rsa->meth->encrypt(rsa, out_len, out, max_out, in, in_len, padding);
}
return rsa_default_encrypt(rsa, out_len, out, max_out, in, in_len, padding);
}
int RSA_public_encrypt(size_t flen, const uint8_t *from, uint8_t *to, RSA *rsa,
int padding) {
size_t out_len;
if (!RSA_encrypt(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
return -1;
}
if (out_len > INT_MAX) {
OPENSSL_PUT_ERROR(RSA, ERR_R_OVERFLOW);
return -1;
}
return out_len;
}
int RSA_sign_raw(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
const uint8_t *in, size_t in_len, int padding) {
if (rsa->meth->sign_raw) {
return rsa->meth->sign_raw(rsa, out_len, out, max_out, in, in_len, padding);
}
return rsa_default_sign_raw(rsa, out_len, out, max_out, in, in_len, padding);
}
int RSA_private_encrypt(size_t flen, const uint8_t *from, uint8_t *to, RSA *rsa,
int padding) {
size_t out_len;
if (!RSA_sign_raw(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
return -1;
}
if (out_len > INT_MAX) {
OPENSSL_PUT_ERROR(RSA, ERR_R_OVERFLOW);
return -1;
}
return out_len;
}
int RSA_decrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
const uint8_t *in, size_t in_len, int padding) {
if (rsa->meth->decrypt) {
return rsa->meth->decrypt(rsa, out_len, out, max_out, in, in_len, padding);
}
return rsa_default_decrypt(rsa, out_len, out, max_out, in, in_len, padding);
}
int RSA_private_decrypt(size_t flen, const uint8_t *from, uint8_t *to, RSA *rsa,
int padding) {
size_t out_len;
if (!RSA_decrypt(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
return -1;
}
if (out_len > INT_MAX) {
OPENSSL_PUT_ERROR(RSA, ERR_R_OVERFLOW);
return -1;
}
return out_len;
}
int RSA_public_decrypt(size_t flen, const uint8_t *from, uint8_t *to, RSA *rsa,
int padding) {
size_t out_len;
if (!RSA_verify_raw(rsa, &out_len, to, RSA_size(rsa), from, flen, padding)) {
return -1;
}
if (out_len > INT_MAX) {
OPENSSL_PUT_ERROR(RSA, ERR_R_OVERFLOW);
return -1;
}
return out_len;
}
unsigned RSA_size(const RSA *rsa) {
if (rsa->meth->size) {
return rsa->meth->size(rsa);
}
return rsa_default_size(rsa);
}
int RSA_is_opaque(const RSA *rsa) {
return rsa->meth && (rsa->meth->flags & RSA_FLAG_OPAQUE);
}
int RSA_supports_digest(const RSA *rsa, const EVP_MD *md) {
if (rsa->meth && rsa->meth->supports_digest) {
return rsa->meth->supports_digest(rsa, md);
}
return 1;
}
int RSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) {
int index;
if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp, dup_func,
free_func)) {
return -1;
}
return index;
}
int RSA_set_ex_data(RSA *d, int idx, void *arg) {
return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
}
void *RSA_get_ex_data(const RSA *d, int idx) {
return CRYPTO_get_ex_data(&d->ex_data, idx);
}
/* SSL_SIG_LENGTH is the size of an SSL/TLS (prior to TLS 1.2) signature: it's
* the length of an MD5 and SHA1 hash. */
static const unsigned SSL_SIG_LENGTH = 36;
/* pkcs1_sig_prefix contains the ASN.1, DER encoded prefix for a hash that is
* to be signed with PKCS#1. */
struct pkcs1_sig_prefix {
/* nid identifies the hash function. */
int nid;
/* len is the number of bytes of |bytes| which are valid. */
uint8_t len;
/* bytes contains the DER bytes. */
uint8_t bytes[19];
};
/* kPKCS1SigPrefixes contains the ASN.1 prefixes for PKCS#1 signatures with
* different hash functions. */
static const struct pkcs1_sig_prefix kPKCS1SigPrefixes[] = {
{
NID_md5,
18,
{0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
0x02, 0x05, 0x05, 0x00, 0x04, 0x10},
},
{
NID_sha1,
15,
{0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05,
0x00, 0x04, 0x14},
},
{
NID_sha224,
19,
{0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1c},
},
{
NID_sha256,
19,
{0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20},
},
{
NID_sha384,
19,
{0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30},
},
{
NID_sha512,
19,
{0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40},
},
{
NID_undef, 0, {0},
},
};
int RSA_add_pkcs1_prefix(uint8_t **out_msg, size_t *out_msg_len,
int *is_alloced, int hash_nid, const uint8_t *msg,
size_t msg_len) {
unsigned i;
if (hash_nid == NID_md5_sha1) {
/* Special case: SSL signature, just check the length. */
if (msg_len != SSL_SIG_LENGTH) {
OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
return 0;
}
*out_msg = (uint8_t*) msg;
*out_msg_len = SSL_SIG_LENGTH;
*is_alloced = 0;
return 1;
}
for (i = 0; kPKCS1SigPrefixes[i].nid != NID_undef; i++) {
const struct pkcs1_sig_prefix *sig_prefix = &kPKCS1SigPrefixes[i];
if (sig_prefix->nid != hash_nid) {
continue;
}
const uint8_t* prefix = sig_prefix->bytes;
unsigned prefix_len = sig_prefix->len;
unsigned signed_msg_len;
uint8_t *signed_msg;
signed_msg_len = prefix_len + msg_len;
if (signed_msg_len < prefix_len) {
OPENSSL_PUT_ERROR(RSA, RSA_R_TOO_LONG);
return 0;
}
signed_msg = OPENSSL_malloc(signed_msg_len);
if (!signed_msg) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
OPENSSL_memcpy(signed_msg, prefix, prefix_len);
OPENSSL_memcpy(signed_msg + prefix_len, msg, msg_len);
*out_msg = signed_msg;
*out_msg_len = signed_msg_len;
*is_alloced = 1;
return 1;
}
OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_ALGORITHM_TYPE);
return 0;
}
int RSA_sign(int hash_nid, const uint8_t *in, unsigned in_len, uint8_t *out,
unsigned *out_len, RSA *rsa) {
const unsigned rsa_size = RSA_size(rsa);
int ret = 0;
uint8_t *signed_msg;
size_t signed_msg_len;
int signed_msg_is_alloced = 0;
size_t size_t_out_len;
if (rsa->meth->sign) {
return rsa->meth->sign(hash_nid, in, in_len, out, out_len, rsa);
}
if (!RSA_add_pkcs1_prefix(&signed_msg, &signed_msg_len,
&signed_msg_is_alloced, hash_nid, in, in_len)) {
return 0;
}
if (rsa_size < RSA_PKCS1_PADDING_SIZE ||
signed_msg_len > rsa_size - RSA_PKCS1_PADDING_SIZE) {
OPENSSL_PUT_ERROR(RSA, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
goto finish;
}
if (RSA_sign_raw(rsa, &size_t_out_len, out, rsa_size, signed_msg,
signed_msg_len, RSA_PKCS1_PADDING)) {
*out_len = size_t_out_len;
ret = 1;
}
finish:
if (signed_msg_is_alloced) {
OPENSSL_free(signed_msg);
}
return ret;
}
int RSA_verify(int hash_nid, const uint8_t *msg, size_t msg_len,
const uint8_t *sig, size_t sig_len, RSA *rsa) {
if (rsa->n == NULL || rsa->e == NULL) {
OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING);
return 0;
}
const size_t rsa_size = RSA_size(rsa);
uint8_t *buf = NULL;
int ret = 0;
uint8_t *signed_msg = NULL;
size_t signed_msg_len, len;
int signed_msg_is_alloced = 0;
if (hash_nid == NID_md5_sha1 && msg_len != SSL_SIG_LENGTH) {
OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
return 0;
}
buf = OPENSSL_malloc(rsa_size);
if (!buf) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
if (!RSA_verify_raw(rsa, &len, buf, rsa_size, sig, sig_len,
RSA_PKCS1_PADDING)) {
goto out;
}
if (!RSA_add_pkcs1_prefix(&signed_msg, &signed_msg_len,
&signed_msg_is_alloced, hash_nid, msg, msg_len)) {
goto out;
}
if (len != signed_msg_len || OPENSSL_memcmp(buf, signed_msg, len) != 0) {
OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_SIGNATURE);
goto out;
}
ret = 1;
out:
OPENSSL_free(buf);
if (signed_msg_is_alloced) {
OPENSSL_free(signed_msg);
}
return ret;
}
static void bn_free_and_null(BIGNUM **bn) {
BN_free(*bn);
*bn = NULL;
}
int RSA_check_key(const RSA *key) {
BIGNUM n, pm1, qm1, lcm, gcd, de, dmp1, dmq1, iqmp_times_q;
BN_CTX *ctx;
int ok = 0, has_crt_values;
if (RSA_is_opaque(key)) {
/* Opaque keys can't be checked. */
return 1;
}
if ((key->p != NULL) != (key->q != NULL)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_ONLY_ONE_OF_P_Q_GIVEN);
return 0;
}
if (!key->n || !key->e) {
OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING);
return 0;
}
if (!key->d || !key->p) {
/* For a public key, or without p and q, there's nothing that can be
* checked. */
return 1;
}
ctx = BN_CTX_new();
if (ctx == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
BN_init(&n);
BN_init(&pm1);
BN_init(&qm1);
BN_init(&lcm);
BN_init(&gcd);
BN_init(&de);
BN_init(&dmp1);
BN_init(&dmq1);
BN_init(&iqmp_times_q);
if (!BN_mul(&n, key->p, key->q, ctx) ||
/* lcm = lcm(prime-1, for all primes) */
!BN_sub(&pm1, key->p, BN_value_one()) ||
!BN_sub(&qm1, key->q, BN_value_one()) ||
!BN_mul(&lcm, &pm1, &qm1, ctx) ||
!BN_gcd(&gcd, &pm1, &qm1, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
goto out;
}
size_t num_additional_primes = 0;
if (key->additional_primes != NULL) {
num_additional_primes = sk_RSA_additional_prime_num(key->additional_primes);
}
for (size_t i = 0; i < num_additional_primes; i++) {
const RSA_additional_prime *ap =
sk_RSA_additional_prime_value(key->additional_primes, i);
if (!BN_mul(&n, &n, ap->prime, ctx) ||
!BN_sub(&pm1, ap->prime, BN_value_one()) ||
!BN_mul(&lcm, &lcm, &pm1, ctx) ||
!BN_gcd(&gcd, &gcd, &pm1, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
goto out;
}
}
if (!BN_div(&lcm, NULL, &lcm, &gcd, ctx) ||
!BN_gcd(&gcd, &pm1, &qm1, ctx) ||
/* de = d*e mod lcm(prime-1, for all primes). */
!BN_mod_mul(&de, key->d, key->e, &lcm, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
goto out;
}
if (BN_cmp(&n, key->n) != 0) {
OPENSSL_PUT_ERROR(RSA, RSA_R_N_NOT_EQUAL_P_Q);
goto out;
}
if (!BN_is_one(&de)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_D_E_NOT_CONGRUENT_TO_1);
goto out;
}
has_crt_values = key->dmp1 != NULL;
if (has_crt_values != (key->dmq1 != NULL) ||
has_crt_values != (key->iqmp != NULL)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_INCONSISTENT_SET_OF_CRT_VALUES);
goto out;
}
if (has_crt_values && num_additional_primes == 0) {
if (/* dmp1 = d mod (p-1) */
!BN_mod(&dmp1, key->d, &pm1, ctx) ||
/* dmq1 = d mod (q-1) */
!BN_mod(&dmq1, key->d, &qm1, ctx) ||
/* iqmp = q^-1 mod p */
!BN_mod_mul(&iqmp_times_q, key->iqmp, key->q, key->p, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
goto out;
}
if (BN_cmp(&dmp1, key->dmp1) != 0 ||
BN_cmp(&dmq1, key->dmq1) != 0 ||
BN_cmp(key->iqmp, key->p) >= 0 ||
!BN_is_one(&iqmp_times_q)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_CRT_VALUES_INCORRECT);
goto out;
}
}
ok = 1;
out:
BN_free(&n);
BN_free(&pm1);
BN_free(&qm1);
BN_free(&lcm);
BN_free(&gcd);
BN_free(&de);
BN_free(&dmp1);
BN_free(&dmq1);
BN_free(&iqmp_times_q);
BN_CTX_free(ctx);
return ok;
}
int RSA_recover_crt_params(RSA *rsa) {
BN_CTX *ctx;
BIGNUM *totient, *rem, *multiple, *p_plus_q, *p_minus_q;
int ok = 0;
if (rsa->n == NULL || rsa->e == NULL || rsa->d == NULL) {
OPENSSL_PUT_ERROR(RSA, RSA_R_EMPTY_PUBLIC_KEY);
return 0;
}
if (rsa->p || rsa->q || rsa->dmp1 || rsa->dmq1 || rsa->iqmp) {
OPENSSL_PUT_ERROR(RSA, RSA_R_CRT_PARAMS_ALREADY_GIVEN);
return 0;
}
if (rsa->additional_primes != NULL) {
OPENSSL_PUT_ERROR(RSA, RSA_R_CANNOT_RECOVER_MULTI_PRIME_KEY);
return 0;
}
/* This uses the algorithm from section 9B of the RSA paper:
* http://people.csail.mit.edu/rivest/Rsapaper.pdf */
ctx = BN_CTX_new();
if (ctx == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
BN_CTX_start(ctx);
totient = BN_CTX_get(ctx);
rem = BN_CTX_get(ctx);
multiple = BN_CTX_get(ctx);
p_plus_q = BN_CTX_get(ctx);
p_minus_q = BN_CTX_get(ctx);
if (totient == NULL || rem == NULL || multiple == NULL || p_plus_q == NULL ||
p_minus_q == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
goto err;
}
/* ed-1 is a small multiple of φ(n). */
if (!BN_mul(totient, rsa->e, rsa->d, ctx) ||
!BN_sub_word(totient, 1) ||
/* φ(n) =
* pq - p - q + 1 =
* n - (p + q) + 1
*
* Thus n is a reasonable estimate for φ(n). So, (ed-1)/n will be very
* close. But, when we calculate the quotient, we'll be truncating it
* because we discard the remainder. Thus (ed-1)/multiple will be >= n,
* which the totient cannot be. So we add one to the estimate.
*
* Consider ed-1 as:
*
* multiple * (n - (p+q) + 1) =
* multiple*n - multiple*(p+q) + multiple
*
* When we divide by n, the first term becomes multiple and, since
* multiple and p+q is tiny compared to n, the second and third terms can
* be ignored. Thus I claim that subtracting one from the estimate is
* sufficient. */
!BN_div(multiple, NULL, totient, rsa->n, ctx) ||
!BN_add_word(multiple, 1) ||
!BN_div(totient, rem, totient, multiple, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
goto err;
}
if (!BN_is_zero(rem)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_RSA_PARAMETERS);
goto err;
}
rsa->p = BN_new();
rsa->q = BN_new();
rsa->dmp1 = BN_new();
rsa->dmq1 = BN_new();
rsa->iqmp = BN_new();
if (rsa->p == NULL || rsa->q == NULL || rsa->dmp1 == NULL || rsa->dmq1 ==
NULL || rsa->iqmp == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
goto err;
}
/* φ(n) = n - (p + q) + 1 =>
* n - totient + 1 = p + q */
if (!BN_sub(p_plus_q, rsa->n, totient) ||
!BN_add_word(p_plus_q, 1) ||
/* p - q = sqrt((p+q)^2 - 4n) */
!BN_sqr(rem, p_plus_q, ctx) ||
!BN_lshift(multiple, rsa->n, 2) ||
!BN_sub(rem, rem, multiple) ||
!BN_sqrt(p_minus_q, rem, ctx) ||
/* q is 1/2 (p+q)-(p-q) */
!BN_sub(rsa->q, p_plus_q, p_minus_q) ||
!BN_rshift1(rsa->q, rsa->q) ||
!BN_div(rsa->p, NULL, rsa->n, rsa->q, ctx) ||
!BN_mul(multiple, rsa->p, rsa->q, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
goto err;
}
if (BN_cmp(multiple, rsa->n) != 0) {
OPENSSL_PUT_ERROR(RSA, RSA_R_INTERNAL_ERROR);
goto err;
}
if (!BN_sub(rem, rsa->p, BN_value_one()) ||
!BN_mod(rsa->dmp1, rsa->d, rem, ctx) ||
!BN_sub(rem, rsa->q, BN_value_one()) ||
!BN_mod(rsa->dmq1, rsa->d, rem, ctx) ||
!BN_mod_inverse(rsa->iqmp, rsa->q, rsa->p, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_BN_LIB);
goto err;
}
ok = 1;
err:
BN_CTX_end(ctx);
BN_CTX_free(ctx);
if (!ok) {
bn_free_and_null(&rsa->p);
bn_free_and_null(&rsa->q);
bn_free_and_null(&rsa->dmp1);
bn_free_and_null(&rsa->dmq1);
bn_free_and_null(&rsa->iqmp);
}
return ok;
}
int RSA_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in,
size_t len) {
if (rsa->meth->private_transform) {
return rsa->meth->private_transform(rsa, out, in, len);
}
return rsa_default_private_transform(rsa, out, in, len);
}
int RSA_blinding_on(RSA *rsa, BN_CTX *ctx) {
return 1;
}