--- /dev/null
+/* 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 <limits.h>
+#include <string.h>
+
+#include <openssl/bn.h>
+#include <openssl/err.h>
+#include <openssl/mem.h>
+#include <openssl/thread.h>
+#include <openssl/type_check.h>
+
+#include "internal.h"
+#include "../bn/internal.h"
+#include "../../internal.h"
+#include "../delocate.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;
+}
+
+static int ensure_fixed_copy(BIGNUM **out, const BIGNUM *in, int width) {
+ if (*out != NULL) {
+ return 1;
+ }
+ BIGNUM *copy = BN_dup(in);
+ if (copy == NULL ||
+ !bn_resize_words(copy, width)) {
+ BN_free(copy);
+ return 0;
+ }
+ *out = copy;
+ return 1;
+}
+
+// freeze_private_key finishes initializing |rsa|'s private key components.
+// After this function has returned, |rsa| may not be changed. This is needed
+// because |RSA| is a public struct and, additionally, OpenSSL 1.1.0 opaquified
+// it wrong (see https://github.com/openssl/openssl/issues/5158).
+static int freeze_private_key(RSA *rsa, BN_CTX *ctx) {
+ CRYPTO_MUTEX_lock_read(&rsa->lock);
+ int frozen = rsa->private_key_frozen;
+ CRYPTO_MUTEX_unlock_read(&rsa->lock);
+ if (frozen) {
+ return 1;
+ }
+
+ int ret = 0;
+ CRYPTO_MUTEX_lock_write(&rsa->lock);
+ if (rsa->private_key_frozen) {
+ ret = 1;
+ goto err;
+ }
+
+ // Pre-compute various intermediate values, as well as copies of private
+ // exponents with correct widths. Note that other threads may concurrently
+ // read from |rsa->n|, |rsa->e|, etc., so any fixes must be in separate
+ // copies. We use |mont_n->N|, |mont_p->N|, and |mont_q->N| as copies of |n|,
+ // |p|, and |q| with the correct minimal widths.
+
+ if (rsa->mont_n == NULL) {
+ rsa->mont_n = BN_MONT_CTX_new_for_modulus(rsa->n, ctx);
+ if (rsa->mont_n == NULL) {
+ goto err;
+ }
+ }
+ const BIGNUM *n_fixed = &rsa->mont_n->N;
+
+ // The only public upper-bound of |rsa->d| is the bit length of |rsa->n|. The
+ // ASN.1 serialization of RSA private keys unfortunately leaks the byte length
+ // of |rsa->d|, but normalize it so we only leak it once, rather than per
+ // operation.
+ if (rsa->d != NULL &&
+ !ensure_fixed_copy(&rsa->d_fixed, rsa->d, n_fixed->width)) {
+ goto err;
+ }
+
+ if (rsa->p != NULL && rsa->q != NULL) {
+ if (rsa->mont_p == NULL) {
+ rsa->mont_p = BN_MONT_CTX_new_for_modulus(rsa->p, ctx);
+ if (rsa->mont_p == NULL) {
+ goto err;
+ }
+ }
+ const BIGNUM *p_fixed = &rsa->mont_p->N;
+
+ if (rsa->mont_q == NULL) {
+ rsa->mont_q = BN_MONT_CTX_new_for_modulus(rsa->q, ctx);
+ if (rsa->mont_q == NULL) {
+ goto err;
+ }
+ }
+ const BIGNUM *q_fixed = &rsa->mont_q->N;
+
+ if (rsa->dmp1 != NULL && rsa->dmq1 != NULL) {
+ // Key generation relies on this function to compute |iqmp|.
+ if (rsa->iqmp == NULL) {
+ BIGNUM *iqmp = BN_new();
+ if (iqmp == NULL ||
+ !bn_mod_inverse_secret_prime(iqmp, rsa->q, rsa->p, ctx,
+ rsa->mont_p)) {
+ BN_free(iqmp);
+ goto err;
+ }
+ rsa->iqmp = iqmp;
+ }
+
+ // CRT components are only publicly bounded by their corresponding
+ // moduli's bit lengths. |rsa->iqmp| is unused outside of this one-time
+ // setup, so we do not compute a fixed-width version of it.
+ if (!ensure_fixed_copy(&rsa->dmp1_fixed, rsa->dmp1, p_fixed->width) ||
+ !ensure_fixed_copy(&rsa->dmq1_fixed, rsa->dmq1, q_fixed->width)) {
+ goto err;
+ }
+
+ // Compute |inv_small_mod_large_mont|. Note that it is always modulo the
+ // larger prime, independent of what is stored in |rsa->iqmp|.
+ if (rsa->inv_small_mod_large_mont == NULL) {
+ BIGNUM *inv_small_mod_large_mont = BN_new();
+ int ok;
+ if (BN_cmp(rsa->p, rsa->q) < 0) {
+ ok = inv_small_mod_large_mont != NULL &&
+ bn_mod_inverse_secret_prime(inv_small_mod_large_mont, rsa->p,
+ rsa->q, ctx, rsa->mont_q) &&
+ BN_to_montgomery(inv_small_mod_large_mont,
+ inv_small_mod_large_mont, rsa->mont_q, ctx);
+ } else {
+ ok = inv_small_mod_large_mont != NULL &&
+ BN_to_montgomery(inv_small_mod_large_mont, rsa->iqmp,
+ rsa->mont_p, ctx);
+ }
+ if (!ok) {
+ BN_free(inv_small_mod_large_mont);
+ goto err;
+ }
+ rsa->inv_small_mod_large_mont = inv_small_mod_large_mont;
+ }
+ }
+ }
+
+ rsa->private_key_frozen = 1;
+ ret = 1;
+
+err:
+ CRYPTO_MUTEX_unlock_write(&rsa->lock);
+ return ret;
+}
+
+size_t rsa_default_size(const RSA *rsa) {
+ return BN_num_bytes(rsa->n);
+}
+
+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->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;
+ 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);
+ 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->mont_n->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);
+ }
+ 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;
+ }
+ OPENSSL_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;
+ }
+ OPENSSL_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:
+ 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);
+ 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:
+ ret =
+ RSA_padding_check_PKCS1_type_2(out, out_len, rsa_size, buf, rsa_size);
+ break;
+ case RSA_PKCS1_OAEP_PADDING:
+ // Use the default parameters: SHA-1 for both hashes and no label.
+ ret = RSA_padding_check_PKCS1_OAEP_mgf1(out, out_len, rsa_size, buf,
+ rsa_size, NULL, 0, NULL, NULL);
+ break;
+ case RSA_NO_PADDING:
+ *out_len = rsa_size;
+ ret = 1;
+ break;
+ default:
+ OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_PADDING_TYPE);
+ goto err;
+ }
+
+ if (!ret) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_PADDING_CHECK_FAILED);
+ }
+
+err:
+ if (padding != RSA_NO_PADDING) {
+ 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;
+
+ 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);
+ 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->mont_n->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:
+ ret =
+ RSA_padding_check_PKCS1_type_1(out, out_len, rsa_size, buf, rsa_size);
+ break;
+ case RSA_NO_PADDING:
+ ret = 1;
+ *out_len = rsa_size;
+ break;
+ default:
+ OPENSSL_PUT_ERROR(RSA, RSA_R_UNKNOWN_PADDING_TYPE);
+ goto err;
+ }
+
+ if (!ret) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_PADDING_CHECK_FAILED);
+ goto err;
+ }
+
+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) {
+ if (rsa->n == NULL || rsa->d == NULL) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING);
+ return 0;
+ }
+
+ 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);
+ goto err;
+ }
+
+ if (!freeze_private_key(rsa, ctx)) {
+ OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ const int do_blinding = (rsa->flags & RSA_FLAG_NO_BLINDING) == 0;
+
+ if (rsa->e == NULL && do_blinding) {
+ // 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|.
+ OPENSSL_PUT_ERROR(RSA, RSA_R_NO_PUBLIC_EXPONENT);
+ goto err;
+ }
+
+ if (do_blinding) {
+ 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 if (!BN_mod_exp_mont_consttime(result, f, rsa->d_fixed, 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 (rsa->e != NULL) {
+ 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 (do_blinding &&
+ !BN_BLINDING_invert(result, blinding, rsa->mont_n, ctx)) {
+ goto err;
+ }
+
+ // The computation should have left |result| as a maximally-wide number, so
+ // that it and serializing does not leak information about the magnitude of
+ // the result.
+ //
+ // See Falko Stenzke, "Manger's Attack revisited", ICICS 2010.
+ assert(result->width == rsa->mont_n->N.width);
+ 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;
+}
+
+// mod_montgomery sets |r| to |I| mod |p|. |I| must already be fully reduced
+// modulo |p| times |q|. It returns one on success and zero on error.
+static int mod_montgomery(BIGNUM *r, const BIGNUM *I, const BIGNUM *p,
+ const BN_MONT_CTX *mont_p, const BIGNUM *q,
+ BN_CTX *ctx) {
+ // Reducing in constant-time with Montgomery reduction requires I <= p * R. We
+ // have I < p * q, so this follows if q < R. In particular, this always holds
+ // if p and q are the same size, which is true for any RSA keys we or anyone
+ // sane generates. For other keys, we fall back to |BN_mod|.
+ if (!bn_less_than_montgomery_R(q, mont_p)) {
+ return BN_mod(r, I, p, ctx);
+ }
+
+ if (// Reduce mod p with Montgomery reduction. This computes I * R^-1 mod p.
+ !BN_from_montgomery(r, I, mont_p, ctx) ||
+ // Multiply by R^2 and do another Montgomery reduction to compute
+ // I * R^-1 * R^2 * R^-1 = I mod p.
+ !BN_to_montgomery(r, r, mont_p, ctx)) {
+ return 0;
+ }
+
+ // By precomputing R^3 mod p (normally |BN_MONT_CTX| only uses R^2 mod p) and
+ // adjusting the API for |BN_mod_exp_mont_consttime|, we could instead compute
+ // I * R mod p here and save a reduction per prime. But this would require
+ // changing the RSAZ code and may not be worth it. Note that the RSAZ code
+ // uses a different radix, so it uses R' = 2^1044. There we'd actually want
+ // R^2 * R', and would futher benefit from a precomputed R'^2. It currently
+ // converts |mont_p->RR| to R'^2.
+ return 1;
+}
+
+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;
+ int ret = 0;
+
+ BN_CTX_start(ctx);
+ r1 = BN_CTX_get(ctx);
+ m1 = BN_CTX_get(ctx);
+ if (r1 == NULL ||
+ m1 == NULL) {
+ goto err;
+ }
+
+ if (!freeze_private_key(rsa, ctx)) {
+ goto err;
+ }
+
+ // Implementing RSA with CRT in constant-time is sensitive to which prime is
+ // larger. Canonicalize fields so that |p| is the larger prime.
+ const BIGNUM *dmp1 = rsa->dmp1_fixed, *dmq1 = rsa->dmq1_fixed;
+ const BN_MONT_CTX *mont_p = rsa->mont_p, *mont_q = rsa->mont_q;
+ if (BN_cmp(rsa->p, rsa->q) < 0) {
+ mont_p = rsa->mont_q;
+ mont_q = rsa->mont_p;
+ dmp1 = rsa->dmq1_fixed;
+ dmq1 = rsa->dmp1_fixed;
+ }
+
+ // Use the minimal-width versions of |n|, |p|, and |q|. Either works, but if
+ // someone gives us non-minimal values, these will be slightly more efficient
+ // on the non-Montgomery operations.
+ const BIGNUM *n = &rsa->mont_n->N;
+ const BIGNUM *p = &mont_p->N;
+ const BIGNUM *q = &mont_q->N;
+
+ // This is a pre-condition for |mod_montgomery|. It was already checked by the
+ // caller.
+ assert(BN_ucmp(I, n) < 0);
+
+ if (// |m1| is the result modulo |q|.
+ !mod_montgomery(r1, I, q, mont_q, p, ctx) ||
+ !BN_mod_exp_mont_consttime(m1, r1, dmq1, q, ctx, mont_q) ||
+ // |r0| is the result modulo |p|.
+ !mod_montgomery(r1, I, p, mont_p, q, ctx) ||
+ !BN_mod_exp_mont_consttime(r0, r1, dmp1, p, ctx, mont_p) ||
+ // Compute r0 = r0 - m1 mod p. |p| is the larger prime, so |m1| is already
+ // fully reduced mod |p|.
+ !bn_mod_sub_consttime(r0, r0, m1, p, ctx) ||
+ // r0 = r0 * iqmp mod p. We use Montgomery multiplication to compute this
+ // in constant time. |inv_small_mod_large_mont| is in Montgomery form and
+ // r0 is not, so the result is taken out of Montgomery form.
+ !BN_mod_mul_montgomery(r0, r0, rsa->inv_small_mod_large_mont, mont_p,
+ ctx) ||
+ // r0 = r0 * q + m1 gives the final result. Reducing modulo q gives m1, so
+ // it is correct mod p. Reducing modulo p gives (r0-m1)*iqmp*q + m1 = r0,
+ // so it is correct mod q. Finally, the result is bounded by [m1, n + m1),
+ // and the result is at least |m1|, so this must be the unique answer in
+ // [0, n).
+ !bn_mul_consttime(r0, r0, q, ctx) ||
+ !bn_uadd_consttime(r0, r0, m1) ||
+ // The result should be bounded by |n|, but fixed-width operations may
+ // bound the width slightly higher, so fix it.
+ !bn_resize_words(r0, n->width)) {
+ goto err;
+ }
+
+ ret = 1;
+
+err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+static int ensure_bignum(BIGNUM **out) {
+ if (*out == NULL) {
+ *out = BN_new();
+ }
+ return *out != NULL;
+}
+
+// kBoringSSLRSASqrtTwo is the BIGNUM representation of ⌊2¹⁵³⁵×√2⌋. This is
+// chosen to give enough precision for 3072-bit RSA, the largest key size FIPS
+// specifies. Key sizes beyond this will round up.
+//
+// To verify this number, check that n² < 2³⁰⁷¹ < (n+1)², where n is value
+// represented here. Note the components are listed in little-endian order. Here
+// is some sample Python code to check:
+//
+// >>> TOBN = lambda a, b: a << 32 | b
+// >>> l = [ <paste the contents of kSqrtTwo> ]
+// >>> n = sum(a * 2**(64*i) for i, a in enumerate(l))
+// >>> n**2 < 2**3071 < (n+1)**2
+// True
+const BN_ULONG kBoringSSLRSASqrtTwo[] = {
+ TOBN(0xdea06241, 0xf7aa81c2), TOBN(0xf6a1be3f, 0xca221307),
+ TOBN(0x332a5e9f, 0x7bda1ebf), TOBN(0x0104dc01, 0xfe32352f),
+ TOBN(0xb8cf341b, 0x6f8236c7), TOBN(0x4264dabc, 0xd528b651),
+ TOBN(0xf4d3a02c, 0xebc93e0c), TOBN(0x81394ab6, 0xd8fd0efd),
+ TOBN(0xeaa4a089, 0x9040ca4a), TOBN(0xf52f120f, 0x836e582e),
+ TOBN(0xcb2a6343, 0x31f3c84d), TOBN(0xc6d5a8a3, 0x8bb7e9dc),
+ TOBN(0x460abc72, 0x2f7c4e33), TOBN(0xcab1bc91, 0x1688458a),
+ TOBN(0x53059c60, 0x11bc337b), TOBN(0xd2202e87, 0x42af1f4e),
+ TOBN(0x78048736, 0x3dfa2768), TOBN(0x0f74a85e, 0x439c7b4a),
+ TOBN(0xa8b1fe6f, 0xdc83db39), TOBN(0x4afc8304, 0x3ab8a2c3),
+ TOBN(0xed17ac85, 0x83339915), TOBN(0x1d6f60ba, 0x893ba84c),
+ TOBN(0x597d89b3, 0x754abe9f), TOBN(0xb504f333, 0xf9de6484),
+};
+const size_t kBoringSSLRSASqrtTwoLen = OPENSSL_ARRAY_SIZE(kBoringSSLRSASqrtTwo);
+
+// generate_prime sets |out| to a prime with length |bits| such that |out|-1 is
+// relatively prime to |e|. If |p| is non-NULL, |out| will also not be close to
+// |p|. |sqrt2| must be ⌊2^(bits-1)×√2⌋ (or a slightly overestimate for large
+// sizes), and |pow2_bits_100| must be 2^(bits-100).
+static int generate_prime(BIGNUM *out, int bits, const BIGNUM *e,
+ const BIGNUM *p, const BIGNUM *sqrt2,
+ const BIGNUM *pow2_bits_100, BN_CTX *ctx,
+ BN_GENCB *cb) {
+ if (bits < 128 || (bits % BN_BITS2) != 0) {
+ OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ assert(BN_is_pow2(pow2_bits_100));
+ assert(BN_is_bit_set(pow2_bits_100, bits - 100));
+
+ // See FIPS 186-4 appendix B.3.3, steps 4 and 5. Note |bits| here is nlen/2.
+
+ // Use the limit from steps 4.7 and 5.8 for most values of |e|. When |e| is 3,
+ // the 186-4 limit is too low, so we use a higher one. Note this case is not
+ // reachable from |RSA_generate_key_fips|.
+ if (bits >= INT_MAX/32) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_MODULUS_TOO_LARGE);
+ return 0;
+ }
+ int limit = BN_is_word(e, 3) ? bits * 32 : bits * 5;
+
+ int ret = 0, tries = 0, rand_tries = 0;
+ BN_CTX_start(ctx);
+ BIGNUM *tmp = BN_CTX_get(ctx);
+ if (tmp == NULL) {
+ goto err;
+ }
+
+ for (;;) {
+ // Generate a random number of length |bits| where the bottom bit is set
+ // (steps 4.2, 4.3, 5.2 and 5.3) and the top bit is set (implied by the
+ // bound checked below in steps 4.4 and 5.5).
+ if (!BN_rand(out, bits, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD) ||
+ !BN_GENCB_call(cb, BN_GENCB_GENERATED, rand_tries++)) {
+ goto err;
+ }
+
+ if (p != NULL) {
+ // If |p| and |out| are too close, try again (step 5.4).
+ if (!bn_abs_sub_consttime(tmp, out, p, ctx)) {
+ goto err;
+ }
+ if (BN_cmp(tmp, pow2_bits_100) <= 0) {
+ continue;
+ }
+ }
+
+ // If out < 2^(bits-1)×√2, try again (steps 4.4 and 5.5). This is equivalent
+ // to out <= ⌊2^(bits-1)×√2⌋, or out <= sqrt2 for FIPS key sizes.
+ //
+ // For larger keys, the comparison is approximate, leaning towards
+ // retrying. That is, we reject a negligible fraction of primes that are
+ // within the FIPS bound, but we will never accept a prime outside the
+ // bound, ensuring the resulting RSA key is the right size.
+ if (BN_cmp(out, sqrt2) <= 0) {
+ continue;
+ }
+
+ // RSA key generation's bottleneck is discarding composites. If it fails
+ // trial division, do not bother computing a GCD or performing Rabin-Miller.
+ if (!bn_odd_number_is_obviously_composite(out)) {
+ // Check gcd(out-1, e) is one (steps 4.5 and 5.6).
+ int relatively_prime;
+ if (!BN_sub(tmp, out, BN_value_one()) ||
+ !bn_is_relatively_prime(&relatively_prime, tmp, e, ctx)) {
+ goto err;
+ }
+ if (relatively_prime) {
+ // Test |out| for primality (steps 4.5.1 and 5.6.1).
+ int is_probable_prime;
+ if (!BN_primality_test(&is_probable_prime, out, BN_prime_checks, ctx, 0,
+ cb)) {
+ goto err;
+ }
+ if (is_probable_prime) {
+ ret = 1;
+ goto err;
+ }
+ }
+ }
+
+ // If we've tried too many times to find a prime, abort (steps 4.7 and
+ // 5.8).
+ tries++;
+ if (tries >= limit) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_TOO_MANY_ITERATIONS);
+ goto err;
+ }
+ if (!BN_GENCB_call(cb, 2, tries)) {
+ goto err;
+ }
+ }
+
+err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) {
+ // See FIPS 186-4 appendix B.3. This function implements a generalized version
+ // of the FIPS algorithm. |RSA_generate_key_fips| performs additional checks
+ // for FIPS-compliant key generation.
+
+ // Always generate RSA keys which are a multiple of 128 bits. Round |bits|
+ // down as needed.
+ bits &= ~127;
+
+ // Reject excessively small keys.
+ if (bits < 256) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_KEY_SIZE_TOO_SMALL);
+ return 0;
+ }
+
+ // Reject excessively large public exponents. Windows CryptoAPI and Go don't
+ // support values larger than 32 bits, so match their limits for generating
+ // keys. (|check_modulus_and_exponent_sizes| uses a slightly more conservative
+ // value, but we don't need to support generating such keys.)
+ // https://github.com/golang/go/issues/3161
+ // https://msdn.microsoft.com/en-us/library/aa387685(VS.85).aspx
+ if (BN_num_bits(e_value) > 32) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_E_VALUE);
+ return 0;
+ }
+
+ int ret = 0;
+ int prime_bits = bits / 2;
+ BN_CTX *ctx = BN_CTX_new();
+ if (ctx == NULL) {
+ goto bn_err;
+ }
+ BN_CTX_start(ctx);
+ BIGNUM *totient = BN_CTX_get(ctx);
+ BIGNUM *pm1 = BN_CTX_get(ctx);
+ BIGNUM *qm1 = BN_CTX_get(ctx);
+ BIGNUM *sqrt2 = BN_CTX_get(ctx);
+ BIGNUM *pow2_prime_bits_100 = BN_CTX_get(ctx);
+ BIGNUM *pow2_prime_bits = BN_CTX_get(ctx);
+ if (totient == NULL || pm1 == NULL || qm1 == NULL || sqrt2 == NULL ||
+ pow2_prime_bits_100 == NULL || pow2_prime_bits == NULL ||
+ !BN_set_bit(pow2_prime_bits_100, prime_bits - 100) ||
+ !BN_set_bit(pow2_prime_bits, prime_bits)) {
+ goto bn_err;
+ }
+
+ // We need the RSA components non-NULL.
+ if (!ensure_bignum(&rsa->n) ||
+ !ensure_bignum(&rsa->d) ||
+ !ensure_bignum(&rsa->e) ||
+ !ensure_bignum(&rsa->p) ||
+ !ensure_bignum(&rsa->q) ||
+ !ensure_bignum(&rsa->dmp1) ||
+ !ensure_bignum(&rsa->dmq1)) {
+ goto bn_err;
+ }
+
+ if (!BN_copy(rsa->e, e_value)) {
+ goto bn_err;
+ }
+
+ // Compute sqrt2 >= ⌊2^(prime_bits-1)×√2⌋.
+ if (!bn_set_words(sqrt2, kBoringSSLRSASqrtTwo, kBoringSSLRSASqrtTwoLen)) {
+ goto bn_err;
+ }
+ int sqrt2_bits = kBoringSSLRSASqrtTwoLen * BN_BITS2;
+ assert(sqrt2_bits == (int)BN_num_bits(sqrt2));
+ if (sqrt2_bits > prime_bits) {
+ // For key sizes up to 3072 (prime_bits = 1536), this is exactly
+ // ⌊2^(prime_bits-1)×√2⌋.
+ if (!BN_rshift(sqrt2, sqrt2, sqrt2_bits - prime_bits)) {
+ goto bn_err;
+ }
+ } else if (prime_bits > sqrt2_bits) {
+ // For key sizes beyond 3072, this is approximate. We err towards retrying
+ // to ensure our key is the right size and round up.
+ if (!BN_add_word(sqrt2, 1) ||
+ !BN_lshift(sqrt2, sqrt2, prime_bits - sqrt2_bits)) {
+ goto bn_err;
+ }
+ }
+ assert(prime_bits == (int)BN_num_bits(sqrt2));
+
+ do {
+ // Generate p and q, each of size |prime_bits|, using the steps outlined in
+ // appendix FIPS 186-4 appendix B.3.3.
+ if (!generate_prime(rsa->p, prime_bits, rsa->e, NULL, sqrt2,
+ pow2_prime_bits_100, ctx, cb) ||
+ !BN_GENCB_call(cb, 3, 0) ||
+ !generate_prime(rsa->q, prime_bits, rsa->e, rsa->p, sqrt2,
+ pow2_prime_bits_100, ctx, cb) ||
+ !BN_GENCB_call(cb, 3, 1)) {
+ goto bn_err;
+ }
+
+ if (BN_cmp(rsa->p, rsa->q) < 0) {
+ BIGNUM *tmp = rsa->p;
+ rsa->p = rsa->q;
+ rsa->q = tmp;
+ }
+
+ // Calculate d = e^(-1) (mod lcm(p-1, q-1)), per FIPS 186-4. This differs
+ // from typical RSA implementations which use (p-1)*(q-1).
+ //
+ // Note this means the size of d might reveal information about p-1 and
+ // q-1. However, we do operations with Chinese Remainder Theorem, so we only
+ // use d (mod p-1) and d (mod q-1) as exponents. Using a minimal totient
+ // does not affect those two values.
+ int no_inverse;
+ if (!bn_usub_consttime(pm1, rsa->p, BN_value_one()) ||
+ !bn_usub_consttime(qm1, rsa->q, BN_value_one()) ||
+ !bn_lcm_consttime(totient, pm1, qm1, ctx) ||
+ !bn_mod_inverse_consttime(rsa->d, &no_inverse, rsa->e, totient, ctx)) {
+ goto bn_err;
+ }
+
+ // Retry if |rsa->d| <= 2^|prime_bits|. See appendix B.3.1's guidance on
+ // values for d.
+ } while (BN_cmp(rsa->d, pow2_prime_bits) <= 0);
+
+ if (// Calculate n.
+ !bn_mul_consttime(rsa->n, rsa->p, rsa->q, ctx) ||
+ // Calculate d mod (p-1).
+ !bn_div_consttime(NULL, rsa->dmp1, rsa->d, pm1, ctx) ||
+ // Calculate d mod (q-1)
+ !bn_div_consttime(NULL, rsa->dmq1, rsa->d, qm1, ctx)) {
+ goto bn_err;
+ }
+ bn_set_minimal_width(rsa->n);
+
+ // Sanity-check that |rsa->n| has the specified size. This is implied by
+ // |generate_prime|'s bounds.
+ if (BN_num_bits(rsa->n) != (unsigned)bits) {
+ OPENSSL_PUT_ERROR(RSA, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ // Call |freeze_private_key| to compute the inverse of q mod p, by way of
+ // |rsa->mont_p|.
+ if (!freeze_private_key(rsa, ctx)) {
+ goto bn_err;
+ }
+
+ // The key generation process is complex and thus error-prone. It could be
+ // disastrous to generate and then use a bad key so double-check that the key
+ // makes sense.
+ if (!RSA_check_key(rsa)) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ ret = 1;
+
+bn_err:
+ if (!ret) {
+ OPENSSL_PUT_ERROR(RSA, ERR_LIB_BN);
+ }
+err:
+ if (ctx != NULL) {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
+ return ret;
+}
+
+int RSA_generate_key_fips(RSA *rsa, int bits, BN_GENCB *cb) {
+ // FIPS 186-4 allows 2048-bit and 3072-bit RSA keys (1024-bit and 1536-bit
+ // primes, respectively) with the prime generation method we use.
+ if (bits != 2048 && bits != 3072) {
+ OPENSSL_PUT_ERROR(RSA, RSA_R_BAD_RSA_PARAMETERS);
+ return 0;
+ }
+
+ BIGNUM *e = BN_new();
+ int ret = e != NULL &&
+ BN_set_word(e, RSA_F4) &&
+ RSA_generate_key_ex(rsa, bits, e, cb) &&
+ RSA_check_fips(rsa);
+ BN_free(e);
+ return ret;
+}
+
+DEFINE_METHOD_FUNCTION(RSA_METHOD, RSA_default_method) {
+ // 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.
+ OPENSSL_memset(out, 0, sizeof(RSA_METHOD));
+ out->common.is_static = 1;
+}
git://repos.xcallymotion.com / motion2.git / blobdiff