| /* 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. |
| * |
| * 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.] |
| */ |
| |
| /* |
| * NB: these functions have been "upgraded", the deprecated versions (which |
| * are compatibility wrappers using these functions) are in rsa_depr.c. - |
| * Geoff |
| */ |
| |
| #include <stdio.h> |
| #include <time.h> |
| #include "cryptlib.h" |
| #include <openssl/bn.h> |
| #include <openssl/rsa.h> |
| |
| static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, |
| BN_GENCB *cb); |
| |
| /* |
| * NB: this wrapper would normally be placed in rsa_lib.c and the static |
| * implementation would probably be in rsa_eay.c. Nonetheless, is kept here |
| * so that we don't introduce a new linker dependency. Eg. any application |
| * that wasn't previously linking object code related to key-generation won't |
| * have to now just because key-generation is part of RSA_METHOD. |
| */ |
| int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) |
| { |
| if (rsa->meth->rsa_keygen) |
| return rsa->meth->rsa_keygen(rsa, bits, e_value, cb); |
| return rsa_builtin_keygen(rsa, bits, e_value, cb); |
| } |
| |
| static int rsa_builtin_keygen(RSA *rsa, int bits, 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; |
| BN_CTX *ctx = NULL; |
| |
| local_r0 = BN_new(); |
| local_d = BN_new(); |
| local_p = BN_new(); |
| if (!local_r0 || !local_d || !local_p) |
| 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 (r3 == NULL) |
| goto err; |
| |
| bitsp = (bits + 1) / 2; |
| bitsq = bits - bitsp; |
| |
| /* 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; |
| |
| 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++)) |
| goto err; |
| } |
| if (!BN_GENCB_call(cb, 3, 0)) |
| goto err; |
| 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, 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); |
| goto err; |
| } |
| if (!BN_sub(r2, rsa->q, 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; |
| } |
| 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 */ |
| 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) */ |
| if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { |
| pr0 = local_r0; |
| 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; |
| 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 (q-1) */ |
| if (!BN_mod(rsa->dmq1, d, r2, ctx)) |
| goto err; |
| |
| /* calculate inverse of q mod p */ |
| if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) { |
| p = local_p; |
| 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; |
| |
| ok = 1; |
| err: |
| if (local_r0) |
| BN_free(local_r0); |
| if (local_d) |
| BN_free(local_d); |
| if (local_p) |
| 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; |
| } |
