| /* 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 <assert.h> |
| #include <string.h> |
| |
| #include <openssl/bn.h> |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| #include <openssl/thread.h> |
| |
| #include "internal.h" |
| #include "../internal.h" |
| |
| |
| static int check_modulus_and_exponent_sizes(const RSA *rsa) { |
| unsigned rsa_bits = BN_num_bits(rsa->n); |
| |
| if (rsa_bits > 16 * 1024) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_MODULUS_TOO_LARGE); |
| return 0; |
| } |
| |
| /* Mitigate DoS attacks by limiting the exponent size. 33 bits was chosen as |
| * the limit based on the recommendations in [1] and [2]. Windows CryptoAPI |
| * doesn't support values larger than 32 bits [3], so it is unlikely that |
| * exponents larger than 32 bits are being used for anything Windows commonly |
| * does. |
| * |
| * [1] https://www.imperialviolet.org/2012/03/16/rsae.html |
| * [2] https://www.imperialviolet.org/2012/03/17/rsados.html |
| * [3] https://msdn.microsoft.com/en-us/library/aa387685(VS.85).aspx */ |
| static const unsigned kMaxExponentBits = 33; |
| |
| if (BN_num_bits(rsa->e) > kMaxExponentBits) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_E_VALUE); |
| return 0; |
| } |
| |
| /* Verify |n > e|. Comparing |rsa_bits| to |kMaxExponentBits| is a small |
| * shortcut to comparing |n| and |e| directly. In reality, |kMaxExponentBits| |
| * is much smaller than the minimum RSA key size that any application should |
| * accept. */ |
| if (rsa_bits <= kMaxExponentBits) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL); |
| return 0; |
| } |
| assert(BN_ucmp(rsa->n, rsa->e) > 0); |
| |
| return 1; |
| } |
| |
| size_t rsa_default_size(const RSA *rsa) { |
| return BN_num_bytes(rsa->n); |
| } |
| |
| int rsa_default_encrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out, |
| const uint8_t *in, size_t in_len, int padding) { |
| const unsigned rsa_size = RSA_size(rsa); |
| BIGNUM *f, *result; |
| uint8_t *buf = NULL; |
| BN_CTX *ctx = NULL; |
| int i, ret = 0; |
| |
| if (max_out < rsa_size) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_OUTPUT_BUFFER_TOO_SMALL); |
| return 0; |
| } |
| |
| if (!check_modulus_and_exponent_sizes(rsa)) { |
| return 0; |
| } |
| |
| ctx = BN_CTX_new(); |
| if (ctx == NULL) { |
| goto err; |
| } |
| |
| BN_CTX_start(ctx); |
| f = BN_CTX_get(ctx); |
| result = BN_CTX_get(ctx); |
| buf = OPENSSL_malloc(rsa_size); |
| if (!f || !result || !buf) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| |
| switch (padding) { |
| case RSA_PKCS1_PADDING: |
| i = RSA_padding_add_PKCS1_type_2(buf, rsa_size, in, in_len); |
| break; |
| case RSA_PKCS1_OAEP_PADDING: |
| /* Use the default parameters: SHA-1 for both hashes and no label. */ |
| i = RSA_padding_add_PKCS1_OAEP_mgf1(buf, rsa_size, in, in_len, |
| NULL, 0, NULL, NULL); |
| break; |
| case RSA_NO_PADDING: |
| i = RSA_padding_add_none(buf, rsa_size, in, in_len); |
| break; |
| default: |
| OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
| goto err; |
| } |
| |
| if (i <= 0) { |
| goto err; |
| } |
| |
| if (BN_bin2bn(buf, rsa_size, f) == NULL) { |
| goto err; |
| } |
| |
| if (BN_ucmp(f, rsa->n) >= 0) { |
| /* usually the padding functions would catch this */ |
| OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
| goto err; |
| } |
| |
| if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) || |
| !BN_mod_exp_mont(result, f, rsa->e, rsa->n, ctx, rsa->mont_n)) { |
| goto err; |
| } |
| |
| /* put in leading 0 bytes if the number is less than the length of the |
| * modulus */ |
| if (!BN_bn2bin_padded(out, rsa_size, result)) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
| goto err; |
| } |
| |
| *out_len = rsa_size; |
| ret = 1; |
| |
| err: |
| if (ctx != NULL) { |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| } |
| if (buf != NULL) { |
| OPENSSL_cleanse(buf, rsa_size); |
| OPENSSL_free(buf); |
| } |
| |
| return ret; |
| } |
| |
| /* MAX_BLINDINGS_PER_RSA defines the maximum number of cached BN_BLINDINGs per |
| * RSA*. Then this limit is exceeded, BN_BLINDING objects will be created and |
| * destroyed as needed. */ |
| #define MAX_BLINDINGS_PER_RSA 1024 |
| |
| /* rsa_blinding_get returns a BN_BLINDING to use with |rsa|. It does this by |
| * allocating one of the cached BN_BLINDING objects in |rsa->blindings|. If |
| * none are free, the cache will be extended by a extra element and the new |
| * BN_BLINDING is returned. |
| * |
| * On success, the index of the assigned BN_BLINDING is written to |
| * |*index_used| and must be passed to |rsa_blinding_release| when finished. */ |
| static BN_BLINDING *rsa_blinding_get(RSA *rsa, unsigned *index_used, |
| BN_CTX *ctx) { |
| assert(ctx != NULL); |
| assert(rsa->mont_n != NULL); |
| |
| BN_BLINDING *ret = NULL; |
| BN_BLINDING **new_blindings; |
| uint8_t *new_blindings_inuse; |
| char overflow = 0; |
| |
| CRYPTO_MUTEX_lock_write(&rsa->lock); |
| |
| unsigned i; |
| for (i = 0; i < rsa->num_blindings; i++) { |
| if (rsa->blindings_inuse[i] == 0) { |
| rsa->blindings_inuse[i] = 1; |
| ret = rsa->blindings[i]; |
| *index_used = i; |
| break; |
| } |
| } |
| |
| if (ret != NULL) { |
| CRYPTO_MUTEX_unlock_write(&rsa->lock); |
| return ret; |
| } |
| |
| overflow = rsa->num_blindings >= MAX_BLINDINGS_PER_RSA; |
| |
| /* We didn't find a free BN_BLINDING to use so increase the length of |
| * the arrays by one and use the newly created element. */ |
| |
| CRYPTO_MUTEX_unlock_write(&rsa->lock); |
| ret = BN_BLINDING_new(); |
| if (ret == NULL) { |
| return NULL; |
| } |
| |
| if (overflow) { |
| /* We cannot add any more cached BN_BLINDINGs so we use |ret| |
| * and mark it for destruction in |rsa_blinding_release|. */ |
| *index_used = MAX_BLINDINGS_PER_RSA; |
| return ret; |
| } |
| |
| CRYPTO_MUTEX_lock_write(&rsa->lock); |
| |
| new_blindings = |
| OPENSSL_malloc(sizeof(BN_BLINDING *) * (rsa->num_blindings + 1)); |
| if (new_blindings == NULL) { |
| goto err1; |
| } |
| memcpy(new_blindings, rsa->blindings, |
| sizeof(BN_BLINDING *) * rsa->num_blindings); |
| new_blindings[rsa->num_blindings] = ret; |
| |
| new_blindings_inuse = OPENSSL_malloc(rsa->num_blindings + 1); |
| if (new_blindings_inuse == NULL) { |
| goto err2; |
| } |
| memcpy(new_blindings_inuse, rsa->blindings_inuse, rsa->num_blindings); |
| new_blindings_inuse[rsa->num_blindings] = 1; |
| *index_used = rsa->num_blindings; |
| |
| OPENSSL_free(rsa->blindings); |
| rsa->blindings = new_blindings; |
| OPENSSL_free(rsa->blindings_inuse); |
| rsa->blindings_inuse = new_blindings_inuse; |
| rsa->num_blindings++; |
| |
| CRYPTO_MUTEX_unlock_write(&rsa->lock); |
| return ret; |
| |
| err2: |
| OPENSSL_free(new_blindings); |
| |
| err1: |
| CRYPTO_MUTEX_unlock_write(&rsa->lock); |
| BN_BLINDING_free(ret); |
| return NULL; |
| } |
| |
| /* rsa_blinding_release marks the cached BN_BLINDING at the given index as free |
| * for other threads to use. */ |
| static void rsa_blinding_release(RSA *rsa, BN_BLINDING *blinding, |
| unsigned blinding_index) { |
| if (blinding_index == MAX_BLINDINGS_PER_RSA) { |
| /* This blinding wasn't cached. */ |
| BN_BLINDING_free(blinding); |
| return; |
| } |
| |
| CRYPTO_MUTEX_lock_write(&rsa->lock); |
| rsa->blindings_inuse[blinding_index] = 0; |
| CRYPTO_MUTEX_unlock_write(&rsa->lock); |
| } |
| |
| /* signing */ |
| int rsa_default_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) { |
| const unsigned rsa_size = RSA_size(rsa); |
| uint8_t *buf = NULL; |
| int i, ret = 0; |
| |
| if (max_out < rsa_size) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_OUTPUT_BUFFER_TOO_SMALL); |
| return 0; |
| } |
| |
| buf = OPENSSL_malloc(rsa_size); |
| if (buf == NULL) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| |
| switch (padding) { |
| case RSA_PKCS1_PADDING: |
| i = RSA_padding_add_PKCS1_type_1(buf, rsa_size, in, in_len); |
| break; |
| case RSA_NO_PADDING: |
| i = RSA_padding_add_none(buf, rsa_size, in, in_len); |
| break; |
| default: |
| OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
| goto err; |
| } |
| |
| if (i <= 0) { |
| goto err; |
| } |
| |
| if (!RSA_private_transform(rsa, out, buf, rsa_size)) { |
| goto err; |
| } |
| |
| *out_len = rsa_size; |
| ret = 1; |
| |
| err: |
| if (buf != NULL) { |
| OPENSSL_cleanse(buf, rsa_size); |
| OPENSSL_free(buf); |
| } |
| |
| return ret; |
| } |
| |
| int rsa_default_decrypt(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out, |
| const uint8_t *in, size_t in_len, int padding) { |
| const unsigned rsa_size = RSA_size(rsa); |
| int r = -1; |
| uint8_t *buf = NULL; |
| int ret = 0; |
| |
| if (max_out < rsa_size) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_OUTPUT_BUFFER_TOO_SMALL); |
| return 0; |
| } |
| |
| if (padding == RSA_NO_PADDING) { |
| buf = out; |
| } else { |
| /* Allocate a temporary buffer to hold the padded plaintext. */ |
| buf = OPENSSL_malloc(rsa_size); |
| if (buf == NULL) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| } |
| |
| if (in_len != rsa_size) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_LEN_NOT_EQUAL_TO_MOD_LEN); |
| goto err; |
| } |
| |
| if (!RSA_private_transform(rsa, buf, in, rsa_size)) { |
| goto err; |
| } |
| |
| switch (padding) { |
| case RSA_PKCS1_PADDING: |
| r = RSA_padding_check_PKCS1_type_2(out, rsa_size, buf, rsa_size); |
| break; |
| case RSA_PKCS1_OAEP_PADDING: |
| /* Use the default parameters: SHA-1 for both hashes and no label. */ |
| r = RSA_padding_check_PKCS1_OAEP_mgf1(out, rsa_size, buf, rsa_size, |
| NULL, 0, NULL, NULL); |
| break; |
| case RSA_NO_PADDING: |
| r = rsa_size; |
| break; |
| default: |
| OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
| goto err; |
| } |
| |
| if (r < 0) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_PADDING_CHECK_FAILED); |
| } else { |
| *out_len = r; |
| ret = 1; |
| } |
| |
| err: |
| if (padding != RSA_NO_PADDING && buf != NULL) { |
| OPENSSL_cleanse(buf, rsa_size); |
| OPENSSL_free(buf); |
| } |
| |
| return ret; |
| } |
| |
| static int mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx); |
| |
| int RSA_verify_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->n == NULL || rsa->e == NULL) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING); |
| return 0; |
| } |
| |
| const unsigned rsa_size = RSA_size(rsa); |
| BIGNUM *f, *result; |
| int r = -1; |
| |
| if (max_out < rsa_size) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_OUTPUT_BUFFER_TOO_SMALL); |
| return 0; |
| } |
| |
| if (in_len != rsa_size) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_LEN_NOT_EQUAL_TO_MOD_LEN); |
| return 0; |
| } |
| |
| if (!check_modulus_and_exponent_sizes(rsa)) { |
| return 0; |
| } |
| |
| BN_CTX *ctx = BN_CTX_new(); |
| if (ctx == NULL) { |
| return 0; |
| } |
| |
| int ret = 0; |
| uint8_t *buf = NULL; |
| |
| BN_CTX_start(ctx); |
| f = BN_CTX_get(ctx); |
| result = BN_CTX_get(ctx); |
| if (f == NULL || result == NULL) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| |
| if (padding == RSA_NO_PADDING) { |
| buf = out; |
| } else { |
| /* Allocate a temporary buffer to hold the padded plaintext. */ |
| buf = OPENSSL_malloc(rsa_size); |
| if (buf == NULL) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| } |
| |
| if (BN_bin2bn(in, in_len, f) == NULL) { |
| goto err; |
| } |
| |
| if (BN_ucmp(f, rsa->n) >= 0) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
| goto err; |
| } |
| |
| if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx) || |
| !BN_mod_exp_mont(result, f, rsa->e, rsa->n, ctx, rsa->mont_n)) { |
| goto err; |
| } |
| |
| if (!BN_bn2bin_padded(buf, rsa_size, result)) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
| goto err; |
| } |
| |
| switch (padding) { |
| case RSA_PKCS1_PADDING: |
| r = RSA_padding_check_PKCS1_type_1(out, rsa_size, buf, rsa_size); |
| break; |
| case RSA_NO_PADDING: |
| r = rsa_size; |
| break; |
| default: |
| OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_PADDING_TYPE); |
| goto err; |
| } |
| |
| if (r < 0) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_PADDING_CHECK_FAILED); |
| } else { |
| *out_len = r; |
| ret = 1; |
| } |
| |
| err: |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| if (buf != out) { |
| OPENSSL_free(buf); |
| } |
| return ret; |
| } |
| |
| int rsa_default_private_transform(RSA *rsa, uint8_t *out, const uint8_t *in, |
| size_t len) { |
| BIGNUM *f, *result; |
| BN_CTX *ctx = NULL; |
| unsigned blinding_index = 0; |
| BN_BLINDING *blinding = NULL; |
| int ret = 0; |
| |
| ctx = BN_CTX_new(); |
| if (ctx == NULL) { |
| goto err; |
| } |
| BN_CTX_start(ctx); |
| f = BN_CTX_get(ctx); |
| result = BN_CTX_get(ctx); |
| |
| if (f == NULL || result == NULL) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| |
| if (BN_bin2bn(in, len, f) == NULL) { |
| goto err; |
| } |
| |
| if (BN_ucmp(f, rsa->n) >= 0) { |
| /* Usually the padding functions would catch this. */ |
| OPENSSL_PUT_ERROR(RSA, RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
| goto err; |
| } |
| |
| if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx)) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
| goto err; |
| } |
| |
| /* We cannot do blinding or verification without |e|, and continuing without |
| * those countermeasures is dangerous. However, the Java/Android RSA API |
| * requires support for keys where only |d| and |n| (and not |e|) are known. |
| * The callers that require that bad behavior set |RSA_FLAG_NO_BLINDING|. */ |
| int disable_security = (rsa->flags & RSA_FLAG_NO_BLINDING) && rsa->e == NULL; |
| |
| if (!disable_security) { |
| /* Keys without public exponents must have blinding explicitly disabled to |
| * be used. */ |
| if (rsa->e == NULL) { |
| OPENSSL_PUT_ERROR(RSA, RSA_R_NO_PUBLIC_EXPONENT); |
| goto err; |
| } |
| |
| blinding = rsa_blinding_get(rsa, &blinding_index, ctx); |
| if (blinding == NULL) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
| goto err; |
| } |
| if (!BN_BLINDING_convert(f, blinding, rsa->e, rsa->mont_n, ctx)) { |
| goto err; |
| } |
| } |
| |
| if (rsa->p != NULL && rsa->q != NULL && rsa->e != NULL && rsa->dmp1 != NULL && |
| rsa->dmq1 != NULL && rsa->iqmp != NULL) { |
| if (!mod_exp(result, f, rsa, ctx)) { |
| goto err; |
| } |
| } else { |
| BIGNUM local_d; |
| BIGNUM *d = NULL; |
| |
| BN_init(&local_d); |
| d = &local_d; |
| BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
| |
| if (!BN_mod_exp_mont_consttime(result, f, d, rsa->n, ctx, rsa->mont_n)) { |
| goto err; |
| } |
| } |
| |
| /* Verify the result to protect against fault attacks as described in the |
| * 1997 paper "On the Importance of Checking Cryptographic Protocols for |
| * Faults" by Dan Boneh, Richard A. DeMillo, and Richard J. Lipton. Some |
| * implementations do this only when the CRT is used, but we do it in all |
| * cases. Section 6 of the aforementioned paper describes an attack that |
| * works when the CRT isn't used. That attack is much less likely to succeed |
| * than the CRT attack, but there have likely been improvements since 1997. |
| * |
| * This check is cheap assuming |e| is small; it almost always is. */ |
| if (!disable_security) { |
| BIGNUM *vrfy = BN_CTX_get(ctx); |
| if (vrfy == NULL || |
| !BN_mod_exp_mont(vrfy, result, rsa->e, rsa->n, ctx, rsa->mont_n) || |
| !BN_equal_consttime(vrfy, f)) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
| goto err; |
| } |
| |
| if (!BN_BLINDING_invert(result, blinding, rsa->mont_n, ctx)) { |
| goto err; |
| } |
| } |
| |
| if (!BN_bn2bin_padded(out, len, result)) { |
| OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR); |
| goto err; |
| } |
| |
| ret = 1; |
| |
| err: |
| if (ctx != NULL) { |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| } |
| if (blinding != NULL) { |
| rsa_blinding_release(rsa, blinding, blinding_index); |
| } |
| |
| return ret; |
| } |
| |
| static int mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) { |
| assert(ctx != NULL); |
| |
| assert(rsa->n != NULL); |
| assert(rsa->e != NULL); |
| assert(rsa->d != NULL); |
| assert(rsa->p != NULL); |
| assert(rsa->q != NULL); |
| assert(rsa->dmp1 != NULL); |
| assert(rsa->dmq1 != NULL); |
| assert(rsa->iqmp != NULL); |
| |
| BIGNUM *r1, *m1, *vrfy; |
| BIGNUM local_dmp1, local_dmq1, local_c, local_r1; |
| BIGNUM *dmp1, *dmq1, *c, *pr1; |
| int ret = 0; |
| size_t i, num_additional_primes = 0; |
| |
| if (rsa->additional_primes != NULL) { |
| num_additional_primes = sk_RSA_additional_prime_num(rsa->additional_primes); |
| } |
| |
| BN_CTX_start(ctx); |
| r1 = BN_CTX_get(ctx); |
| m1 = BN_CTX_get(ctx); |
| vrfy = BN_CTX_get(ctx); |
| if (r1 == NULL || |
| m1 == NULL || |
| vrfy == NULL) { |
| goto err; |
| } |
| |
| { |
| BIGNUM local_p, local_q; |
| BIGNUM *p = NULL, *q = NULL; |
| |
| /* Make sure BN_mod in Montgomery initialization uses BN_FLG_CONSTTIME. */ |
| BN_init(&local_p); |
| p = &local_p; |
| BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); |
| |
| BN_init(&local_q); |
| q = &local_q; |
| BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME); |
| |
| if (!BN_MONT_CTX_set_locked(&rsa->mont_p, &rsa->lock, p, ctx) || |
| !BN_MONT_CTX_set_locked(&rsa->mont_q, &rsa->lock, q, ctx)) { |
| goto err; |
| } |
| } |
| |
| if (!BN_MONT_CTX_set_locked(&rsa->mont_n, &rsa->lock, rsa->n, ctx)) { |
| goto err; |
| } |
| |
| /* compute I mod q */ |
| c = &local_c; |
| BN_with_flags(c, I, BN_FLG_CONSTTIME); |
| if (!BN_mod(r1, c, rsa->q, ctx)) { |
| goto err; |
| } |
| |
| /* compute r1^dmq1 mod q */ |
| dmq1 = &local_dmq1; |
| BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); |
| if (!BN_mod_exp_mont_consttime(m1, r1, dmq1, rsa->q, ctx, rsa->mont_q)) { |
| goto err; |
| } |
| |
| /* compute I mod p */ |
| c = &local_c; |
| BN_with_flags(c, I, BN_FLG_CONSTTIME); |
| if (!BN_mod(r1, c, rsa->p, ctx)) { |
| goto err; |
| } |
| |
| /* compute r1^dmp1 mod p */ |
| dmp1 = &local_dmp1; |
| BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); |
| if (!BN_mod_exp_mont_consttime(r0, r1, dmp1, rsa->p, ctx, rsa->mont_p)) { |
| goto err; |
| } |
| |
| if (!BN_sub(r0, r0, m1)) { |
| goto err; |
| } |
| /* This will help stop the size of r0 increasing, which does |
| * affect the multiply if it optimised for a power of 2 size */ |
| if (BN_is_negative(r0)) { |
| if (!BN_add(r0, r0, rsa->p)) { |
| goto err; |
| } |
| } |
| |
| if (!BN_mul(r1, r0, rsa->iqmp, ctx)) { |
| goto err; |
| } |
| |
| /* Turn BN_FLG_CONSTTIME flag on before division operation */ |
| pr1 = &local_r1; |
| BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); |
| |
| if (!BN_mod(r0, pr1, rsa->p, ctx)) { |
| goto err; |
| } |
| |
| /* If p < q it is occasionally possible for the correction of |
| * adding 'p' if r0 is negative above to leave the result still |
| * negative. This can break the private key operations: the following |
| * second correction should *always* correct this rare occurrence. |
| * This will *never* happen with OpenSSL generated keys because |
| * they ensure p > q [steve] */ |
| if (BN_is_negative(r0)) { |
| if (!BN_add(r0, r0, rsa->p)) { |
| goto err; |
| } |
| } |
| if (!BN_mul(r1, r0, rsa->q, ctx)) { |
| goto err; |
| } |
| if (!BN_add(r0, r1, m1)) { |
| goto err; |
| } |
| |
| for (i = 0; i < num_additional_primes; i++) { |
| /* multi-prime RSA. */ |
| BIGNUM local_exp, local_prime; |
| BIGNUM *exp = &local_exp, *prime = &local_prime; |
| RSA_additional_prime *ap = |
| sk_RSA_additional_prime_value(rsa->additional_primes, i); |
| |
| BN_with_flags(exp, ap->exp, BN_FLG_CONSTTIME); |
| BN_with_flags(prime, ap->prime, BN_FLG_CONSTTIME); |
| |
| /* c will already point to a BIGNUM with the correct flags. */ |
| if (!BN_mod(r1, c, prime, ctx)) { |
| goto err; |
| } |
| |
| if (!BN_MONT_CTX_set_locked(&ap->mont, &rsa->lock, prime, ctx) || |
| !BN_mod_exp_mont_consttime(m1, r1, exp, prime, ctx, ap->mont)) { |
| goto err; |
| } |
| |
| BN_set_flags(m1, BN_FLG_CONSTTIME); |
| |
| if (!BN_sub(m1, m1, r0) || |
| !BN_mul(m1, m1, ap->coeff, ctx) || |
| !BN_mod(m1, m1, prime, ctx) || |
| (BN_is_negative(m1) && !BN_add(m1, m1, prime)) || |
| !BN_mul(m1, m1, ap->r, ctx) || |
| !BN_add(r0, r0, m1)) { |
| goto err; |
| } |
| } |
| |
| ret = 1; |
| |
| err: |
| BN_CTX_end(ctx); |
| return ret; |
| } |
| |
| int rsa_default_multi_prime_keygen(RSA *rsa, int bits, int num_primes, |
| BIGNUM *e_value, BN_GENCB *cb) { |
| BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp; |
| BIGNUM local_r0, local_d, local_p; |
| BIGNUM *pr0, *d, *p; |
| int prime_bits, ok = -1, n = 0, i, j; |
| BN_CTX *ctx = NULL; |
| STACK_OF(RSA_additional_prime) *additional_primes = NULL; |
| |
| if (num_primes < 2) { |
| ok = 0; /* we set our own err */ |
| OPENSSL_PUT_ERROR(RSA, RSA_R_MUST_HAVE_AT_LEAST_TWO_PRIMES); |
| goto err; |
| } |
| |
| ctx = BN_CTX_new(); |
| if (ctx == NULL) { |
| goto err; |
| } |
| BN_CTX_start(ctx); |
| r0 = BN_CTX_get(ctx); |
| r1 = BN_CTX_get(ctx); |
| r2 = BN_CTX_get(ctx); |
| r3 = BN_CTX_get(ctx); |
| if (r0 == NULL || r1 == NULL || r2 == NULL || r3 == NULL) { |
| goto err; |
| } |
| |
| if (num_primes > 2) { |
| additional_primes = sk_RSA_additional_prime_new_null(); |
| if (additional_primes == NULL) { |
| goto err; |
| } |
| } |
| |
| for (i = 2; i < num_primes; i++) { |
| RSA_additional_prime *ap = OPENSSL_malloc(sizeof(RSA_additional_prime)); |
| if (ap == NULL) { |
| goto err; |
| } |
| memset(ap, 0, sizeof(RSA_additional_prime)); |
| ap->prime = BN_new(); |
| ap->exp = BN_new(); |
| ap->coeff = BN_new(); |
| ap->r = BN_new(); |
| if (ap->prime == NULL || |
| ap->exp == NULL || |
| ap->coeff == NULL || |
| ap->r == NULL || |
| !sk_RSA_additional_prime_push(additional_primes, ap)) { |
| RSA_additional_prime_free(ap); |
| goto err; |
| } |
| } |
| |
| /* We need the RSA components non-NULL */ |
| if (!rsa->n && ((rsa->n = BN_new()) == NULL)) { |
| goto err; |
| } |
| if (!rsa->d && ((rsa->d = BN_new()) == NULL)) { |
| goto err; |
| } |
| if (!rsa->e && ((rsa->e = BN_new()) == NULL)) { |
| goto err; |
| } |
| if (!rsa->p && ((rsa->p = BN_new()) == NULL)) { |
| goto err; |
| } |
| if (!rsa->q && ((rsa->q = BN_new()) == NULL)) { |
| goto err; |
| } |
| if (!rsa->dmp1 && ((rsa->dmp1 = BN_new()) == NULL)) { |
| goto err; |
| } |
| if (!rsa->dmq1 && ((rsa->dmq1 = BN_new()) == NULL)) { |
| goto err; |
| } |
| if (!rsa->iqmp && ((rsa->iqmp = BN_new()) == NULL)) { |
| goto err; |
| } |
| |
| if (!BN_copy(rsa->e, e_value)) { |
| goto err; |
| } |
| |
| /* generate p and q */ |
| prime_bits = (bits + (num_primes - 1)) / num_primes; |
| for (;;) { |
| if (!BN_generate_prime_ex(rsa->p, prime_bits, 0, NULL, NULL, cb) || |
| !BN_sub(r2, rsa->p, BN_value_one()) || |
| !BN_gcd(r1, r2, rsa->e, ctx)) { |
| goto err; |
| } |
| if (BN_is_one(r1)) { |
| break; |
| } |
| if (!BN_GENCB_call(cb, 2, n++)) { |
| goto err; |
| } |
| } |
| if (!BN_GENCB_call(cb, 3, 0)) { |
| goto err; |
| } |
| prime_bits = ((bits - prime_bits) + (num_primes - 2)) / (num_primes - 1); |
| for (;;) { |
| /* When generating ridiculously small keys, we can get stuck |
| * continually regenerating the same prime values. Check for |
| * this and bail if it happens 3 times. */ |
| unsigned int degenerate = 0; |
| do { |
| if (!BN_generate_prime_ex(rsa->q, prime_bits, 0, NULL, NULL, cb)) { |
| goto err; |
| } |
| } while ((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3)); |
| if (degenerate == 3) { |
| ok = 0; /* we set our own err */ |
| OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL); |
| goto err; |
| } |
| if (!BN_sub(r2, rsa->q, BN_value_one()) || |
| !BN_gcd(r1, r2, rsa->e, ctx)) { |
| goto err; |
| } |
| if (BN_is_one(r1)) { |
| break; |
| } |
| if (!BN_GENCB_call(cb, 2, n++)) { |
| goto err; |
| } |
| } |
| |
| if (!BN_GENCB_call(cb, 3, 1) || |
| !BN_mul(rsa->n, rsa->p, rsa->q, ctx)) { |
| goto err; |
| } |
| |
| for (i = 2; i < num_primes; i++) { |
| RSA_additional_prime *ap = |
| sk_RSA_additional_prime_value(additional_primes, i - 2); |
| prime_bits = ((bits - BN_num_bits(rsa->n)) + (num_primes - (i + 1))) / |
| (num_primes - i); |
| |
| for (;;) { |
| if (!BN_generate_prime_ex(ap->prime, prime_bits, 0, NULL, NULL, cb)) { |
| goto err; |
| } |
| if (BN_cmp(rsa->p, ap->prime) == 0 || |
| BN_cmp(rsa->q, ap->prime) == 0) { |
| continue; |
| } |
| |
| for (j = 0; j < i - 2; j++) { |
| if (BN_cmp(sk_RSA_additional_prime_value(additional_primes, j)->prime, |
| ap->prime) == 0) { |
| break; |
| } |
| } |
| if (j != i - 2) { |
| continue; |
| } |
| |
| if (!BN_sub(r2, ap->prime, BN_value_one()) || |
| !BN_gcd(r1, r2, rsa->e, ctx)) { |
| goto err; |
| } |
| |
| if (!BN_is_one(r1)) { |
| continue; |
| } |
| if (i != num_primes - 1) { |
| break; |
| } |
| |
| /* For the last prime we'll check that it makes n large enough. In the |
| * two prime case this isn't a problem because we generate primes with |
| * the top two bits set and so the product is always of the expected |
| * size. In the multi prime case, this doesn't follow. */ |
| if (!BN_mul(r1, rsa->n, ap->prime, ctx)) { |
| goto err; |
| } |
| if (BN_num_bits(r1) == (unsigned) bits) { |
| break; |
| } |
| |
| if (!BN_GENCB_call(cb, 2, n++)) { |
| goto err; |
| } |
| } |
| |
| /* ap->r is is the product of all the primes prior to the current one |
| * (including p and q). */ |
| if (!BN_copy(ap->r, rsa->n)) { |
| goto err; |
| } |
| if (i == num_primes - 1) { |
| /* In the case of the last prime, we calculated n as |r1| in the loop |
| * above. */ |
| if (!BN_copy(rsa->n, r1)) { |
| goto err; |
| } |
| } else if (!BN_mul(rsa->n, rsa->n, ap->prime, ctx)) { |
| goto err; |
| } |
| |
| if (!BN_GENCB_call(cb, 3, 1)) { |
| goto err; |
| } |
| } |
| |
| if (BN_cmp(rsa->p, rsa->q) < 0) { |
| tmp = rsa->p; |
| rsa->p = rsa->q; |
| rsa->q = tmp; |
| } |
| |
| /* calculate d */ |
| if (!BN_sub(r1, rsa->p, BN_value_one())) { |
| goto err; /* p-1 */ |
| } |
| if (!BN_sub(r2, rsa->q, BN_value_one())) { |
| goto err; /* q-1 */ |
| } |
| if (!BN_mul(r0, r1, r2, ctx)) { |
| goto err; /* (p-1)(q-1) */ |
| } |
| for (i = 2; i < num_primes; i++) { |
| RSA_additional_prime *ap = |
| sk_RSA_additional_prime_value(additional_primes, i - 2); |
| if (!BN_sub(r3, ap->prime, BN_value_one()) || |
| !BN_mul(r0, r0, r3, ctx)) { |
| goto err; |
| } |
| } |
| pr0 = &local_r0; |
| BN_with_flags(pr0, r0, BN_FLG_CONSTTIME); |
| if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx)) { |
| goto err; /* d */ |
| } |
| |
| /* set up d for correct BN_FLG_CONSTTIME flag */ |
| d = &local_d; |
| BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
| |
| /* calculate d mod (p-1) */ |
| if (!BN_mod(rsa->dmp1, d, r1, ctx)) { |
| goto err; |
| } |
| |
| /* calculate d mod (q-1) */ |
| if (!BN_mod(rsa->dmq1, d, r2, ctx)) { |
| goto err; |
| } |
| |
| /* calculate inverse of q mod p */ |
| p = &local_p; |
| BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); |
| |
| if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx)) { |
| goto err; |
| } |
| |
| for (i = 2; i < num_primes; i++) { |
| RSA_additional_prime *ap = |
| sk_RSA_additional_prime_value(additional_primes, i - 2); |
| if (!BN_sub(ap->exp, ap->prime, BN_value_one()) || |
| !BN_mod(ap->exp, rsa->d, ap->exp, ctx) || |
| !BN_mod_inverse(ap->coeff, ap->r, ap->prime, ctx)) { |
| goto err; |
| } |
| } |
| |
| ok = 1; |
| rsa->additional_primes = additional_primes; |
| additional_primes = NULL; |
| |
| err: |
| if (ok == -1) { |
| OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN); |
| ok = 0; |
| } |
| if (ctx != NULL) { |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| } |
| sk_RSA_additional_prime_pop_free(additional_primes, |
| RSA_additional_prime_free); |
| return ok; |
| } |
| |
| int rsa_default_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) { |
| return rsa_default_multi_prime_keygen(rsa, bits, 2 /* num primes */, e_value, |
| cb); |
| } |
| |
| /* All of the methods are NULL to make it easier for the compiler/linker to drop |
| * unused functions. The wrapper functions will select the appropriate |
| * |rsa_default_*| implementation. */ |
| const RSA_METHOD RSA_default_method = { |
| { |
| 0 /* references */, |
| 1 /* is_static */, |
| }, |
| NULL /* app_data */, |
| |
| NULL /* init */, |
| NULL /* finish (defaults to rsa_default_finish) */, |
| |
| NULL /* size (defaults to rsa_default_size) */, |
| |
| NULL /* sign */, |
| NULL /* verify */, |
| |
| NULL /* encrypt (defaults to rsa_default_encrypt) */, |
| NULL /* sign_raw (defaults to rsa_default_sign_raw) */, |
| NULL /* decrypt (defaults to rsa_default_decrypt) */, |
| NULL /* verify_raw (defaults to rsa_default_verify_raw) */, |
| |
| NULL /* private_transform (defaults to rsa_default_private_transform) */, |
| |
| NULL /* mod_exp (ignored) */, |
| NULL /* bn_mod_exp (ignored) */, |
| |
| RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE, |
| |
| NULL /* keygen (defaults to rsa_default_keygen) */, |
| NULL /* multi_prime_keygen (defaults to rsa_default_multi_prime_keygen) */, |
| |
| NULL /* supports_digest */, |
| }; |