X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frsa%2Frsa_gen.c;h=7f0a25648140c4e89d0497bdc5c105fd7002b6c2;hp=d23d47d03e45ca4c5ded54e750c43246487724b0;hb=8f57662771356882561b98d6add06a16dc479f9b;hpb=fd7d252060c427b2e567295845a61d824539443b diff --git a/crypto/rsa/rsa_gen.c b/crypto/rsa/rsa_gen.c index d23d47d03e..7f0a256481 100644 --- a/crypto/rsa/rsa_gen.c +++ b/crypto/rsa/rsa_gen.c @@ -1,59 +1,10 @@ -/* 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 1995-2018 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 */ /* @@ -66,9 +17,9 @@ #include #include "internal/cryptlib.h" #include -#include +#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); /* @@ -80,17 +31,59 @@ static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, */ 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; - 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; + unsigned long error = 0; + + if (bits < RSA_MIN_MODULUS_BITS) { + ok = 0; /* we set our own err */ + RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL); + goto err; + } + + 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) @@ -99,12 +92,15 @@ static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, 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)) @@ -124,126 +120,265 @@ static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, 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; + } + BN_set_flags(prime, BN_FLG_CONSTTIME); + + 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; + ERR_set_mark(); + BN_set_flags(r2, BN_FLG_CONSTTIME); + if (BN_mod_inverse(r1, r2, rsa->e, ctx) != NULL) { + /* GCD == 1 since inverse exists */ + break; + } + error = ERR_peek_last_error(); + if (ERR_GET_LIB(error) == ERR_LIB_BN + && ERR_GET_REASON(error) == BN_R_NO_INVERSE) { + /* GCD != 1 */ + ERR_pop_to_mark(); + } else { + goto err; + } + 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) */ + 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 *local_r0 = NULL, *pr0; - if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { - pr0 = local_r0 = BN_new(); - if (local_r0 == NULL) - goto err; - BN_with_flags(pr0, r0, BN_FLG_CONSTTIME); - } else { - pr0 = r0; - } + BIGNUM *pr0 = BN_new(); + + if (pr0 == NULL) + goto err; + + BN_with_flags(pr0, r0, BN_FLG_CONSTTIME); if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx)) { - BN_free(local_r0); + BN_free(pr0); goto err; /* d */ } - /* We MUST free local_r0 before any further use of r0 */ - BN_free(local_r0); + /* We MUST free pr0 before any further use of r0 */ + BN_free(pr0); } { - BIGNUM *local_d = NULL, *d; - /* set up d for correct BN_FLG_CONSTTIME flag */ - if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { - d = local_d = BN_new(); - if (local_d == NULL) - goto err; - BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); - } else { - d = rsa->d; - } + BIGNUM *d = BN_new(); - if ( /* calculate d mod (p-1) */ - !BN_mod(rsa->dmp1, d, r1, ctx) - /* calculate d mod (q-1) */ + if (d == NULL) + goto err; + + BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); + + /* 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(local_d); + BN_free(d); goto err; } - /* We MUST free local_d before any further use of rsa->d */ - BN_free(local_d); + + /* 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 *local_p = NULL, *p; + BIGNUM *p = BN_new(); + + if (p == NULL) + goto err; + BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); /* calculate inverse of q mod p */ - if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { - p = local_p = BN_new(); - if (local_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)) { - BN_free(local_p); + BN_free(p); goto err; } - /* We MUST free local_p before any further use of rsa->p */ - BN_free(local_p); + + /* 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; @@ -255,6 +390,5 @@ static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, if (ctx != NULL) BN_CTX_end(ctx); BN_CTX_free(ctx); - return ok; }