/* 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_grpc/rsa.h>
#include <limits.h>
#include <string.h>
#include <openssl_grpc/bn.h>
#include <openssl_grpc/digest.h>
#include <openssl_grpc/engine.h>
#include <openssl_grpc/err.h>
#include <openssl_grpc/ex_data.h>
#include <openssl_grpc/md5.h>
#include <openssl_grpc/mem.h>
#include <openssl_grpc/nid.h>
#include <openssl_grpc/sha.h>
#include <openssl_grpc/thread.h>
#include "../bn/internal.h"
#include "../delocate.h"
#include "../../internal.h"
#include "internal.h"
// RSA_R_BLOCK_TYPE_IS_NOT_02 is part of the legacy SSLv23 padding scheme.
// Cryptography.io depends on this error code.
OPENSSL_DECLARE_ERROR_REASON(RSA, BLOCK_TYPE_IS_NOT_02)
DEFINE_STATIC_EX_DATA_CLASS(g_rsa_ex_data_class)
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_rsa_ex_data_class_bss_get(), rsa, &rsa->ex_data);
CRYPTO_MUTEX_cleanup(&rsa->lock);
METHOD_unref(rsa->meth);
OPENSSL_free(rsa);
return NULL;
}
return rsa;
}
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_rsa_ex_data_class_bss_get(), rsa, &rsa->ex_data);
BN_free(rsa->n);
BN_free(rsa->e);
BN_free(rsa->d);
BN_free(rsa->p);
BN_free(rsa->q);
BN_free(rsa->dmp1);
BN_free(rsa->dmq1);
BN_free(rsa->iqmp);
BN_MONT_CTX_free(rsa->mont_n);
BN_MONT_CTX_free(rsa->mont_p);
BN_MONT_CTX_free(rsa->mont_q);
BN_free(rsa->d_fixed);
BN_free(rsa->dmp1_fixed);
BN_free(rsa->dmq1_fixed);
BN_free(rsa->inv_small_mod_large_mont);
for (u = 0; u < rsa->num_blindings; u++) {
BN_BLINDING_free(rsa->blindings[u]);
}
OPENSSL_free(rsa->blindings);
OPENSSL_free(rsa->blindings_inuse);
CRYPTO_MUTEX_cleanup(&rsa->lock);
OPENSSL_free(rsa);
}
int RSA_up_ref(RSA *rsa) {
CRYPTO_refcount_inc(&rsa->references);
return 1;
}
unsigned RSA_bits(const RSA *rsa) { return BN_num_bits(rsa->n); }
const BIGNUM *RSA_get0_n(const RSA *rsa) { return rsa->n; }
const BIGNUM *RSA_get0_e(const RSA *rsa) { return rsa->e; }
const BIGNUM *RSA_get0_d(const RSA *rsa) { return rsa->d; }
const BIGNUM *RSA_get0_p(const RSA *rsa) { return rsa->p; }
const BIGNUM *RSA_get0_q(const RSA *rsa) { return rsa->q; }
const BIGNUM *RSA_get0_dmp1(const RSA *rsa) { return rsa->dmp1; }
const BIGNUM *RSA_get0_dmq1(const RSA *rsa) { return rsa->dmq1; }
const BIGNUM *RSA_get0_iqmp(const RSA *rsa) { return rsa->iqmp; }
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;
}
}
const RSA_PSS_PARAMS *RSA_get0_pss_params(const RSA *rsa) {
// We do not support the id-RSASSA-PSS key encoding. If we add support later,
// the |maskHash| field should be filled in for OpenSSL compatibility.
return NULL;
}
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_set0_key(RSA *rsa, BIGNUM *n, BIGNUM *e, BIGNUM *d) {
if ((rsa->n == NULL && n == NULL) ||
(rsa->e == NULL && e == NULL)) {
return 0;
}
if (n != NULL) {
BN_free(rsa->n);
rsa->n = n;
}
if (e != NULL) {
BN_free(rsa->e);
rsa->e = e;
}
if (d != NULL) {
BN_free(rsa->d);
rsa->d = d;
}
return 1;
}
int RSA_set0_factors(RSA *rsa, BIGNUM *p, BIGNUM *q) {
if ((rsa->p == NULL && p == NULL) ||
(rsa->q == NULL && q == NULL)) {
return 0;
}
if (p != NULL) {
BN_free(rsa->p);
rsa->p = p;
}
if (q != NULL) {
BN_free(rsa->q);
rsa->q = q;
}
return 1;
}
int RSA_set0_crt_params(RSA *rsa, BIGNUM *dmp1, BIGNUM *dmq1, BIGNUM *iqmp) {
if ((rsa->dmp1 == NULL && dmp1 == NULL) ||
(rsa->dmq1 == NULL && dmq1 == NULL) ||
(rsa->iqmp == NULL && iqmp == NULL)) {
return 0;
}
if (dmp1 != NULL) {
BN_free(rsa->dmp1);
rsa->dmp1 = dmp1;
}
if (dmq1 != NULL) {
BN_free(rsa->dmq1);
rsa->dmq1 = dmq1;
}
if (iqmp != NULL) {
BN_free(rsa->iqmp);
rsa->iqmp = iqmp;
}
return 1;
}
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_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
CRYPTO_EX_dup *dup_unused, CRYPTO_EX_free *free_func) {
int index;
if (!CRYPTO_get_ex_new_index(g_rsa_ex_data_class_bss_get(), &index, argl,
argp, free_func)) {
return -1;
}
return index;
}
int RSA_set_ex_data(RSA *rsa, int idx, void *arg) {
return CRYPTO_set_ex_data(&rsa->ex_data, idx, arg);
}
void *RSA_get_ex_data(const RSA *rsa, int idx) {
return CRYPTO_get_ex_data(&rsa->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;
// hash_len is the expected length of the hash function.
uint8_t hash_len;
// 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,
MD5_DIGEST_LENGTH,
18,
{0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d,
0x02, 0x05, 0x05, 0x00, 0x04, 0x10},
},
{
NID_sha1,
SHA_DIGEST_LENGTH,
15,
{0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05,
0x00, 0x04, 0x14},
},
{
NID_sha224,
SHA224_DIGEST_LENGTH,
19,
{0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1c},
},
{
NID_sha256,
SHA256_DIGEST_LENGTH,
19,
{0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20},
},
{
NID_sha384,
SHA384_DIGEST_LENGTH,
19,
{0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30},
},
{
NID_sha512,
SHA512_DIGEST_LENGTH,
19,
{0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03,
0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40},
},
{
NID_undef, 0, 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 *digest,
size_t digest_len) {
unsigned i;
if (hash_nid == NID_md5_sha1) {
// Special case: SSL signature, just check the length.
if (digest_len != SSL_SIG_LENGTH) {
OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
return 0;
}
*out_msg = (uint8_t *)digest;
*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;
}
if (digest_len != sig_prefix->hash_len) {
OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
return 0;
}
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 + digest_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, digest, digest_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 *digest, unsigned digest_len,
uint8_t *out, unsigned *out_len, RSA *rsa) {
const unsigned rsa_size = RSA_size(rsa);
int ret = 0;
uint8_t *signed_msg = NULL;
size_t signed_msg_len = 0;
int signed_msg_is_alloced = 0;
size_t size_t_out_len;
if (rsa->meth->sign) {
return rsa->meth->sign(hash_nid, digest, digest_len, out, out_len, rsa);
}
if (!RSA_add_pkcs1_prefix(&signed_msg, &signed_msg_len,
&signed_msg_is_alloced, hash_nid, digest,
digest_len) ||
!RSA_sign_raw(rsa, &size_t_out_len, out, rsa_size, signed_msg,
signed_msg_len, RSA_PKCS1_PADDING)) {
goto err;
}
*out_len = size_t_out_len;
ret = 1;
err:
if (signed_msg_is_alloced) {
OPENSSL_free(signed_msg);
}
return ret;
}
int RSA_sign_pss_mgf1(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
const uint8_t *digest, size_t digest_len,
const EVP_MD *md, const EVP_MD *mgf1_md, int salt_len) {
if (digest_len != EVP_MD_size(md)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
return 0;
}
size_t padded_len = RSA_size(rsa);
uint8_t *padded = OPENSSL_malloc(padded_len);
if (padded == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
int ret = RSA_padding_add_PKCS1_PSS_mgf1(rsa, padded, digest, md, mgf1_md,
salt_len) &&
RSA_sign_raw(rsa, out_len, out, max_out, padded, padded_len,
RSA_NO_PADDING);
OPENSSL_free(padded);
return ret;
}
int RSA_verify(int hash_nid, const uint8_t *digest, size_t digest_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 = 0, len;
int signed_msg_is_alloced = 0;
if (hash_nid == NID_md5_sha1 && digest_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, digest,
digest_len)) {
goto out;
}
// Check that no other information follows the hash value (FIPS 186-4 Section
// 5.5) and it matches the expected hash.
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;
}
int RSA_verify_pss_mgf1(RSA *rsa, const uint8_t *digest, size_t digest_len,
const EVP_MD *md, const EVP_MD *mgf1_md, int salt_len,
const uint8_t *sig, size_t sig_len) {
if (digest_len != EVP_MD_size(md)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_INVALID_MESSAGE_LENGTH);
return 0;
}
size_t em_len = RSA_size(rsa);
uint8_t *em = OPENSSL_malloc(em_len);
if (em == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
int ret = 0;
if (!RSA_verify_raw(rsa, &em_len, em, em_len, sig, sig_len, RSA_NO_PADDING)) {
goto err;
}
if (em_len != RSA_size(rsa)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
goto err;
}
ret = RSA_verify_PKCS1_PSS_mgf1(rsa, digest, md, mgf1_md, em, salt_len);
err:
OPENSSL_free(em);
return ret;
}
static int check_mod_inverse(int *out_ok, const BIGNUM *a, const BIGNUM *ainv,
const BIGNUM *m, unsigned m_min_bits,
BN_CTX *ctx) {
if (BN_is_negative(ainv) || BN_cmp(ainv, m) >= 0) {
*out_ok = 0;
return 1;
}
// Note |bn_mul_consttime| and |bn_div_consttime| do not scale linearly, but
// checking |ainv| is in range bounds the running time, assuming |m|'s bounds
// were checked by the caller.
BN_CTX_start(ctx);
BIGNUM *tmp = BN_CTX_get(ctx);
int ret = tmp != NULL &&
bn_mul_consttime(tmp, a, ainv, ctx) &&
bn_div_consttime(NULL, tmp, tmp, m, m_min_bits, ctx);
if (ret) {
*out_ok = BN_is_one(tmp);
}
BN_CTX_end(ctx);
return ret;
}
int RSA_check_key(const RSA *key) {
// TODO(davidben): RSA key initialization is spread across
// |rsa_check_public_key|, |RSA_check_key|, |freeze_private_key|, and
// |BN_MONT_CTX_set_locked| as a result of API issues. See
// https://crbug.com/boringssl/316. As a result, we inconsistently check RSA
// invariants. We should fix this and integrate that logic.
if (RSA_is_opaque(key)) {
// Opaque keys can't be checked.
return 1;
}
if (!rsa_check_public_key(key)) {
return 0;
}
if ((key->p != NULL) != (key->q != NULL)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_ONLY_ONE_OF_P_Q_GIVEN);
return 0;
}
// |key->d| must be bounded by |key->n|. This ensures bounds on |RSA_bits|
// translate to bounds on the running time of private key operations.
if (key->d != NULL &&
(BN_is_negative(key->d) || BN_cmp(key->d, key->n) >= 0)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_D_OUT_OF_RANGE);
return 0;
}
if (key->d == NULL || key->p == NULL) {
// For a public key, or without p and q, there's nothing that can be
// checked.
return 1;
}
BN_CTX *ctx = BN_CTX_new();
if (ctx == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
BIGNUM tmp, de, pm1, qm1, dmp1, dmq1;
int ok = 0;
BN_init(&tmp);
BN_init(&de);
BN_init(&pm1);
BN_init(&qm1);
BN_init(&dmp1);
BN_init(&dmq1);
// Check that p * q == n. Before we multiply, we check that p and q are in
// bounds, to avoid a DoS vector in |bn_mul_consttime| below. Note that
// n was bound by |rsa_check_public_key|.
if (BN_is_negative(key->p) || BN_cmp(key->p, key->n) >= 0 ||
BN_is_negative(key->q) || BN_cmp(key->q, key->n) >= 0) {
OPENSSL_PUT_ERROR(RSA, RSA_R_N_NOT_EQUAL_P_Q);
goto out;
}
if (!bn_mul_consttime(&tmp, key->p, key->q, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
goto out;
}
if (BN_cmp(&tmp, key->n) != 0) {
OPENSSL_PUT_ERROR(RSA, RSA_R_N_NOT_EQUAL_P_Q);
goto out;
}
// d must be an inverse of e mod the Carmichael totient, lcm(p-1, q-1), but it
// may be unreduced because other implementations use the Euler totient. We
// simply check that d * e is one mod p-1 and mod q-1. Note d and e were bound
// by earlier checks in this function.
if (!bn_usub_consttime(&pm1, key->p, BN_value_one()) ||
!bn_usub_consttime(&qm1, key->q, BN_value_one())) {
OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
goto out;
}
const unsigned pm1_bits = BN_num_bits(&pm1);
const unsigned qm1_bits = BN_num_bits(&qm1);
if (!bn_mul_consttime(&de, key->d, key->e, ctx) ||
!bn_div_consttime(NULL, &tmp, &de, &pm1, pm1_bits, ctx) ||
!bn_div_consttime(NULL, &de, &de, &qm1, qm1_bits, ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
goto out;
}
if (!BN_is_one(&tmp) || !BN_is_one(&de)) {
OPENSSL_PUT_ERROR(RSA, RSA_R_D_E_NOT_CONGRUENT_TO_1);
goto out;
}
int 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) {
int dmp1_ok, dmq1_ok, iqmp_ok;
if (!check_mod_inverse(&dmp1_ok, key->e, key->dmp1, &pm1, pm1_bits, ctx) ||
!check_mod_inverse(&dmq1_ok, key->e, key->dmq1, &qm1, qm1_bits, ctx) ||
// |p| is odd, so |pm1| and |p| have the same bit width. If they didn't,
// we only need a lower bound anyway.
!check_mod_inverse(&iqmp_ok, key->q, key->iqmp, key->p, pm1_bits,
ctx)) {
OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
goto out;
}
if (!dmp1_ok || !dmq1_ok || !iqmp_ok) {
OPENSSL_PUT_ERROR(RSA, RSA_R_CRT_VALUES_INCORRECT);
goto out;
}
}
ok = 1;
out:
BN_free(&tmp);
BN_free(&de);
BN_free(&pm1);
BN_free(&qm1);
BN_free(&dmp1);
BN_free(&dmq1);
BN_CTX_free(ctx);
return ok;
}
// This is the product of the 132 smallest odd primes, from 3 to 751.
static const BN_ULONG kSmallFactorsLimbs[] = {
TOBN(0xc4309333, 0x3ef4e3e1), TOBN(0x71161eb6, 0xcd2d655f),
TOBN(0x95e2238c, 0x0bf94862), TOBN(0x3eb233d3, 0x24f7912b),
TOBN(0x6b55514b, 0xbf26c483), TOBN(0x0a84d817, 0x5a144871),
TOBN(0x77d12fee, 0x9b82210a), TOBN(0xdb5b93c2, 0x97f050b3),
TOBN(0x4acad6b9, 0x4d6c026b), TOBN(0xeb7751f3, 0x54aec893),
TOBN(0xdba53368, 0x36bc85c4), TOBN(0xd85a1b28, 0x7f5ec78e),
TOBN(0x2eb072d8, 0x6b322244), TOBN(0xbba51112, 0x5e2b3aea),
TOBN(0x36ed1a6c, 0x0e2486bf), TOBN(0x5f270460, 0xec0c5727),
0x000017b1
};
DEFINE_LOCAL_DATA(BIGNUM, g_small_factors) {
out->d = (BN_ULONG *) kSmallFactorsLimbs;
out->width = OPENSSL_ARRAY_SIZE(kSmallFactorsLimbs);
out->dmax = out->width;
out->neg = 0;
out->flags = BN_FLG_STATIC_DATA;
}
int RSA_check_fips(RSA *key) {
if (RSA_is_opaque(key)) {
// Opaque keys can't be checked.
OPENSSL_PUT_ERROR(RSA, RSA_R_PUBLIC_KEY_VALIDATION_FAILED);
return 0;
}
if (!RSA_check_key(key)) {
return 0;
}
BN_CTX *ctx = BN_CTX_new();
if (ctx == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
BIGNUM small_gcd;
BN_init(&small_gcd);
int ret = 1;
// Perform partial public key validation of RSA keys (SP 800-89 5.3.3).
// Although this is not for primality testing, SP 800-89 cites an RSA
// primality testing algorithm, so we use |BN_prime_checks_for_generation| to
// match. This is only a plausibility test and we expect the value to be
// composite, so too few iterations will cause us to reject the key, not use
// an implausible one.
enum bn_primality_result_t primality_result;
if (BN_num_bits(key->e) <= 16 ||
BN_num_bits(key->e) > 256 ||
!BN_is_odd(key->n) ||
!BN_is_odd(key->e) ||
!BN_gcd(&small_gcd, key->n, g_small_factors(), ctx) ||
!BN_is_one(&small_gcd) ||
!BN_enhanced_miller_rabin_primality_test(&primality_result, key->n,
BN_prime_checks_for_generation,
ctx, NULL) ||
primality_result != bn_non_prime_power_composite) {
OPENSSL_PUT_ERROR(RSA, RSA_R_PUBLIC_KEY_VALIDATION_FAILED);
ret = 0;
}
BN_free(&small_gcd);
BN_CTX_free(ctx);
if (!ret || key->d == NULL || key->p == NULL) {
// On a failure or on only a public key, there's nothing else can be
// checked.
return ret;
}
// FIPS pairwise consistency test (FIPS 140-2 4.9.2). Per FIPS 140-2 IG,
// section 9.9, it is not known whether |rsa| will be used for signing or
// encryption, so either pair-wise consistency self-test is acceptable. We
// perform a signing test.
uint8_t data[32] = {0};
unsigned sig_len = RSA_size(key);
uint8_t *sig = OPENSSL_malloc(sig_len);
if (sig == NULL) {
OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE);
return 0;
}
if (!RSA_sign(NID_sha256, data, sizeof(data), sig, &sig_len, key)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
ret = 0;
goto cleanup;
}
#if defined(BORINGSSL_FIPS_BREAK_RSA_PWCT)
data[0] = ~data[0];
#endif
if (!RSA_verify(NID_sha256, data, sizeof(data), sig, sig_len, key)) {
OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
ret = 0;
}
cleanup:
OPENSSL_free(sig);
return ret;
}
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_flags(const RSA *rsa) { return rsa->flags; }
int RSA_blinding_on(RSA *rsa, BN_CTX *ctx) {
return 1;
}