-/* crypto/rsa/rsa_gen.c */
-/* 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.
+/*
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
*
- * 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.]
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
*/
/*
#include <time.h>
#include "internal/cryptlib.h"
#include <openssl/bn.h>
-#include <openssl/rsa.h>
+#include "rsa_locl.h"
-static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
+static int rsa_builtin_keygen(RSA *rsa, int bits, int primes, BIGNUM *e_value,
BN_GENCB *cb);
/*
*/
int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
{
- if (rsa->meth->rsa_keygen)
+ if (rsa->meth->rsa_keygen != NULL)
return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
- return rsa_builtin_keygen(rsa, bits, e_value, cb);
+
+ return RSA_generate_multi_prime_key(rsa, bits, RSA_DEFAULT_PRIME_NUM,
+ e_value, cb);
}
-static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
+int RSA_generate_multi_prime_key(RSA *rsa, int bits, int primes,
+ BIGNUM *e_value, BN_GENCB *cb)
+{
+ /* multi-prime is only supported with the builtin key generation */
+ if (rsa->meth->rsa_multi_prime_keygen != NULL) {
+ return rsa->meth->rsa_multi_prime_keygen(rsa, bits, primes,
+ e_value, cb);
+ } else if (rsa->meth->rsa_keygen != NULL) {
+ /*
+ * However, if rsa->meth implements only rsa_keygen, then we
+ * have to honour it in 2-prime case and assume that it wouldn't
+ * know what to do with multi-prime key generated by builtin
+ * subroutine...
+ */
+ if (primes == 2)
+ return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
+ else
+ return 0;
+ }
+
+ return rsa_builtin_keygen(rsa, bits, primes, e_value, cb);
+}
+
+static int rsa_builtin_keygen(RSA *rsa, int bits, int 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 bitsp, bitsq, ok = -1, n = 0;
+ BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *tmp, *prime;
+ int ok = -1, n = 0, bitsr[RSA_MAX_PRIME_NUM], bitse = 0;
+ int i = 0, quo = 0, rmd = 0, adj = 0, retries = 0;
+ RSA_PRIME_INFO *pinfo = NULL;
+ STACK_OF(RSA_PRIME_INFO) *prime_infos = NULL;
BN_CTX *ctx = NULL;
+ BN_ULONG bitst = 0;
+
+ /*
+ * When generating ridiculously small keys, we can get stuck
+ * continually regenerating the same prime values.
+ */
+ if (bits < 16) {
+ ok = 0; /* we set our own err */
+ RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
+ goto err;
+ }
- local_r0 = BN_new();
- local_d = BN_new();
- local_p = BN_new();
- if (local_r0 == NULL || local_d == NULL || local_p == NULL)
+ if (primes < RSA_DEFAULT_PRIME_NUM || primes > rsa_multip_cap(bits)) {
+ ok = 0; /* we set our own err */
+ RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_PRIME_NUM_INVALID);
goto err;
+ }
ctx = BN_CTX_new();
if (ctx == NULL)
r0 = BN_CTX_get(ctx);
r1 = BN_CTX_get(ctx);
r2 = BN_CTX_get(ctx);
- r3 = BN_CTX_get(ctx);
- if (r3 == NULL)
+ if (r2 == NULL)
goto err;
- bitsp = (bits + 1) / 2;
- bitsq = bits - bitsp;
+ /* divide bits into 'primes' pieces evenly */
+ quo = bits / primes;
+ rmd = bits % primes;
+
+ for (i = 0; i < primes; i++)
+ bitsr[i] = (i < rmd) ? quo + 1 : quo;
/* We need the RSA components non-NULL */
if (!rsa->n && ((rsa->n = BN_new()) == NULL))
if (!rsa->iqmp && ((rsa->iqmp = BN_secure_new()) == NULL))
goto err;
- BN_copy(rsa->e, e_value);
-
- /* generate p and q */
- for (;;) {
- if (!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))
- goto err;
- if (!BN_sub(r2, rsa->p, BN_value_one()))
- goto err;
- if (!BN_gcd(r1, r2, rsa->e, ctx))
- goto err;
- if (BN_is_one(r1))
- break;
- if (!BN_GENCB_call(cb, 2, n++))
+ /* initialize multi-prime components */
+ if (primes > RSA_DEFAULT_PRIME_NUM) {
+ rsa->version = RSA_ASN1_VERSION_MULTI;
+ prime_infos = sk_RSA_PRIME_INFO_new_reserve(NULL, primes - 2);
+ if (prime_infos == NULL)
goto err;
+ if (rsa->prime_infos != NULL) {
+ /* could this happen? */
+ sk_RSA_PRIME_INFO_pop_free(rsa->prime_infos, rsa_multip_info_free);
+ }
+ rsa->prime_infos = prime_infos;
+
+ /* prime_info from 2 to |primes| -1 */
+ for (i = 2; i < primes; i++) {
+ pinfo = rsa_multip_info_new();
+ if (pinfo == NULL)
+ goto err;
+ (void)sk_RSA_PRIME_INFO_push(prime_infos, pinfo);
+ }
}
- if (!BN_GENCB_call(cb, 3, 0))
+
+ if (BN_copy(rsa->e, e_value) == NULL)
goto err;
- for (;;) {
+
+ /* generate p, q and other primes (if any) */
+ for (i = 0; i < primes; i++) {
+ adj = 0;
+ retries = 0;
+
+ if (i == 0) {
+ prime = rsa->p;
+ } else if (i == 1) {
+ prime = rsa->q;
+ } else {
+ pinfo = sk_RSA_PRIME_INFO_value(prime_infos, i - 2);
+ prime = pinfo->r;
+ }
+
+ for (;;) {
+ redo:
+ if (!BN_generate_prime_ex(prime, bitsr[i] + adj, 0, NULL, NULL, cb))
+ goto err;
+ /*
+ * prime should not be equal to p, q, r_3...
+ * (those primes prior to this one)
+ */
+ {
+ int j;
+
+ for (j = 0; j < i; j++) {
+ BIGNUM *prev_prime;
+
+ if (j == 0)
+ prev_prime = rsa->p;
+ else if (j == 1)
+ prev_prime = rsa->q;
+ else
+ prev_prime = sk_RSA_PRIME_INFO_value(prime_infos,
+ j - 2)->r;
+
+ if (!BN_cmp(prime, prev_prime)) {
+ goto redo;
+ }
+ }
+ }
+ if (!BN_sub(r2, prime, BN_value_one()))
+ goto err;
+ if (!BN_gcd(r1, r2, rsa->e, ctx))
+ goto err;
+ if (BN_is_one(r1))
+ break;
+ if (!BN_GENCB_call(cb, 2, n++))
+ goto err;
+ }
+
+ bitse += bitsr[i];
+
+ /* calculate n immediately to see if it's sufficient */
+ if (i == 1) {
+ /* we get at least 2 primes */
+ if (!BN_mul(r1, rsa->p, rsa->q, ctx))
+ goto err;
+ } else if (i != 0) {
+ /* modulus n = p * q * r_3 * r_4 ... */
+ if (!BN_mul(r1, rsa->n, prime, ctx))
+ goto err;
+ } else {
+ /* i == 0, do nothing */
+ if (!BN_GENCB_call(cb, 3, i))
+ goto err;
+ continue;
+ }
/*
- * 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.
+ * if |r1|, product of factors so far, is not as long as expected
+ * (by checking the first 4 bits are less than 0x9 or greater than
+ * 0xF). If so, re-generate the last prime.
+ *
+ * NOTE: This actually can't happen in two-prime case, because of
+ * the way factors are generated.
+ *
+ * Besides, another consideration is, for multi-prime case, even the
+ * length modulus is as long as expected, the modulus could start at
+ * 0x8, which could be utilized to distinguish a multi-prime private
+ * key by using the modulus in a certificate. This is also covered
+ * by checking the length should not be less than 0x9.
*/
- unsigned int degenerate = 0;
- do {
- if (!BN_generate_prime_ex(rsa->q, bitsq, 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 */
- RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
+ if (!BN_rshift(r2, r1, bitse - 4))
goto err;
+ bitst = BN_get_word(r2);
+
+ if (bitst < 0x9 || bitst > 0xF) {
+ /*
+ * For keys with more than 4 primes, we attempt longer factor to
+ * meet length requirement.
+ *
+ * Otherwise, we just re-generate the prime with the same length.
+ *
+ * This strategy has the following goals:
+ *
+ * 1. 1024-bit factors are effcient when using 3072 and 4096-bit key
+ * 2. stay the same logic with normal 2-prime key
+ */
+ bitse -= bitsr[i];
+ if (!BN_GENCB_call(cb, 2, n++))
+ goto err;
+ if (primes > 4) {
+ if (bitst < 0x9)
+ adj++;
+ else
+ adj--;
+ } else if (retries == 4) {
+ /*
+ * re-generate all primes from scratch, mainly used
+ * in 4 prime case to avoid long loop. Max retry times
+ * is set to 4.
+ */
+ i = -1;
+ bitse = 0;
+ continue;
+ }
+ retries++;
+ goto redo;
}
- if (!BN_sub(r2, rsa->q, BN_value_one()))
+ /* save product of primes for further use, for multi-prime only */
+ if (i > 1 && BN_copy(pinfo->pp, rsa->n) == NULL)
goto err;
- if (!BN_gcd(r1, r2, rsa->e, ctx))
+ if (BN_copy(rsa->n, r1) == NULL)
goto err;
- if (BN_is_one(r1))
- break;
- if (!BN_GENCB_call(cb, 2, n++))
+ if (!BN_GENCB_call(cb, 3, i))
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 n */
- if (!BN_mul(rsa->n, rsa->p, rsa->q, ctx))
- goto err;
-
/* calculate d */
+
+ /* p - 1 */
if (!BN_sub(r1, rsa->p, BN_value_one()))
- goto err; /* p-1 */
+ goto err;
+ /* q - 1 */
if (!BN_sub(r2, rsa->q, BN_value_one()))
- goto err; /* q-1 */
+ goto err;
+ /* (p - 1)(q - 1) */
if (!BN_mul(r0, r1, r2, ctx))
- goto err; /* (p-1)(q-1) */
- if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
- pr0 = local_r0;
+ goto err;
+ /* multi-prime */
+ for (i = 2; i < primes; i++) {
+ pinfo = sk_RSA_PRIME_INFO_value(prime_infos, i - 2);
+ /* save r_i - 1 to pinfo->d temporarily */
+ if (!BN_sub(pinfo->d, pinfo->r, BN_value_one()))
+ goto err;
+ if (!BN_mul(r0, r0, pinfo->d, ctx))
+ goto err;
+ }
+
+ {
+ BIGNUM *pr0 = BN_new();
+
+ if (pr0 == NULL)
+ goto err;
+
BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
- } else
- pr0 = r0;
- if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx))
- goto err; /* d */
-
- /* set up d for correct BN_FLG_CONSTTIME flag */
- if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
- d = local_d;
+ if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx)) {
+ BN_free(pr0);
+ goto err; /* d */
+ }
+ /* We MUST free pr0 before any further use of r0 */
+ BN_free(pr0);
+ }
+
+ {
+ BIGNUM *d = BN_new();
+
+ if (d == NULL)
+ goto err;
+
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
- } else
- d = rsa->d;
- /* calculate d mod (p-1) */
- if (!BN_mod(rsa->dmp1, d, r1, ctx))
- goto err;
+ /* calculate d mod (p-1) and d mod (q - 1) */
+ if (!BN_mod(rsa->dmp1, d, r1, ctx)
+ || !BN_mod(rsa->dmq1, d, r2, ctx)) {
+ BN_free(d);
+ goto err;
+ }
- /* calculate d mod (q-1) */
- if (!BN_mod(rsa->dmq1, d, r2, ctx))
- goto err;
+ /* calculate CRT exponents */
+ for (i = 2; i < primes; i++) {
+ pinfo = sk_RSA_PRIME_INFO_value(prime_infos, i - 2);
+ /* pinfo->d == r_i - 1 */
+ if (!BN_mod(pinfo->d, d, pinfo->d, ctx)) {
+ BN_free(d);
+ goto err;
+ }
+ }
+
+ /* We MUST free d before any further use of rsa->d */
+ BN_free(d);
+ }
+
+ {
+ BIGNUM *p = BN_new();
- /* calculate inverse of q mod p */
- if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
- p = local_p;
+ if (p == NULL)
+ goto err;
BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
- } else
- p = rsa->p;
- if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx))
- goto err;
+
+ /* calculate inverse of q mod p */
+ if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx)) {
+ BN_free(p);
+ goto err;
+ }
+
+ /* calculate CRT coefficient for other primes */
+ for (i = 2; i < primes; i++) {
+ pinfo = sk_RSA_PRIME_INFO_value(prime_infos, i - 2);
+ BN_with_flags(p, pinfo->r, BN_FLG_CONSTTIME);
+ if (!BN_mod_inverse(pinfo->t, pinfo->pp, p, ctx)) {
+ BN_free(p);
+ goto err;
+ }
+ }
+
+ /* We MUST free p before any further use of rsa->p */
+ BN_free(p);
+ }
ok = 1;
err:
- BN_free(local_r0);
- BN_free(local_d);
- BN_free(local_p);
if (ok == -1) {
RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, ERR_LIB_BN);
ok = 0;
if (ctx != NULL)
BN_CTX_end(ctx);
BN_CTX_free(ctx);
-
return ok;
}
projects / openssl.git / blobdiff