Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 1 | /* crypto/rsa/rsa_gen.c */ |
| 2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This package is an SSL implementation written |
| 6 | * by Eric Young (eay@cryptsoft.com). |
| 7 | * The implementation was written so as to conform with Netscapes SSL. |
| 8 | * |
| 9 | * This library is free for commercial and non-commercial use as long as |
| 10 | * the following conditions are aheared to. The following conditions |
| 11 | * apply to all code found in this distribution, be it the RC4, RSA, |
| 12 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| 13 | * included with this distribution is covered by the same copyright terms |
| 14 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| 15 | * |
| 16 | * Copyright remains Eric Young's, and as such any Copyright notices in |
| 17 | * the code are not to be removed. |
| 18 | * If this package is used in a product, Eric Young should be given attribution |
| 19 | * as the author of the parts of the library used. |
| 20 | * This can be in the form of a textual message at program startup or |
| 21 | * in documentation (online or textual) provided with the package. |
| 22 | * |
| 23 | * Redistribution and use in source and binary forms, with or without |
| 24 | * modification, are permitted provided that the following conditions |
| 25 | * are met: |
| 26 | * 1. Redistributions of source code must retain the copyright |
| 27 | * notice, this list of conditions and the following disclaimer. |
| 28 | * 2. Redistributions in binary form must reproduce the above copyright |
| 29 | * notice, this list of conditions and the following disclaimer in the |
| 30 | * documentation and/or other materials provided with the distribution. |
| 31 | * 3. All advertising materials mentioning features or use of this software |
| 32 | * must display the following acknowledgement: |
| 33 | * "This product includes cryptographic software written by |
| 34 | * Eric Young (eay@cryptsoft.com)" |
| 35 | * The word 'cryptographic' can be left out if the rouines from the library |
| 36 | * being used are not cryptographic related :-). |
| 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
| 38 | * the apps directory (application code) you must include an acknowledgement: |
| 39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| 40 | * |
| 41 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| 42 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 43 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 44 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 45 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 46 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 47 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 49 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 50 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 51 | * SUCH DAMAGE. |
| 52 | * |
| 53 | * The licence and distribution terms for any publically available version or |
| 54 | * derivative of this code cannot be changed. i.e. this code cannot simply be |
| 55 | * copied and put under another distribution licence |
| 56 | * [including the GNU Public Licence.] |
| 57 | */ |
| 58 | |
| 59 | |
| 60 | /* NB: these functions have been "upgraded", the deprecated versions (which are |
| 61 | * compatibility wrappers using these functions) are in rsa_depr.c. |
| 62 | * - Geoff |
| 63 | */ |
| 64 | |
| 65 | #include <stdio.h> |
| 66 | #include <time.h> |
| 67 | #include "cryptlib.h" |
| 68 | #include <openssl/bn.h> |
| 69 | #include <openssl/rsa.h> |
Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 70 | |
| 71 | static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb); |
| 72 | |
| 73 | /* NB: this wrapper would normally be placed in rsa_lib.c and the static |
| 74 | * implementation would probably be in rsa_eay.c. Nonetheless, is kept here so |
| 75 | * that we don't introduce a new linker dependency. Eg. any application that |
| 76 | * wasn't previously linking object code related to key-generation won't have to |
| 77 | * now just because key-generation is part of RSA_METHOD. */ |
| 78 | int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) |
| 79 | { |
Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 80 | if(rsa->meth->rsa_keygen) |
| 81 | return rsa->meth->rsa_keygen(rsa, bits, e_value, cb); |
Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 82 | return rsa_builtin_keygen(rsa, bits, e_value, cb); |
| 83 | } |
| 84 | |
| 85 | static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb) |
| 86 | { |
| 87 | BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp; |
| 88 | BIGNUM local_r0,local_d,local_p; |
| 89 | BIGNUM *pr0,*d,*p; |
| 90 | int bitsp,bitsq,ok= -1,n=0; |
| 91 | BN_CTX *ctx=NULL; |
| 92 | |
| 93 | ctx=BN_CTX_new(); |
| 94 | if (ctx == NULL) goto err; |
| 95 | BN_CTX_start(ctx); |
| 96 | r0 = BN_CTX_get(ctx); |
| 97 | r1 = BN_CTX_get(ctx); |
| 98 | r2 = BN_CTX_get(ctx); |
| 99 | r3 = BN_CTX_get(ctx); |
| 100 | if (r3 == NULL) goto err; |
| 101 | |
| 102 | bitsp=(bits+1)/2; |
| 103 | bitsq=bits-bitsp; |
| 104 | |
| 105 | /* We need the RSA components non-NULL */ |
| 106 | if(!rsa->n && ((rsa->n=BN_new()) == NULL)) goto err; |
| 107 | if(!rsa->d && ((rsa->d=BN_new()) == NULL)) goto err; |
| 108 | if(!rsa->e && ((rsa->e=BN_new()) == NULL)) goto err; |
| 109 | if(!rsa->p && ((rsa->p=BN_new()) == NULL)) goto err; |
| 110 | if(!rsa->q && ((rsa->q=BN_new()) == NULL)) goto err; |
| 111 | if(!rsa->dmp1 && ((rsa->dmp1=BN_new()) == NULL)) goto err; |
| 112 | if(!rsa->dmq1 && ((rsa->dmq1=BN_new()) == NULL)) goto err; |
| 113 | if(!rsa->iqmp && ((rsa->iqmp=BN_new()) == NULL)) goto err; |
| 114 | |
| 115 | BN_copy(rsa->e, e_value); |
| 116 | |
| 117 | /* generate p and q */ |
| 118 | for (;;) |
| 119 | { |
| 120 | if(!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb)) |
| 121 | goto err; |
| 122 | if (!BN_sub(r2,rsa->p,BN_value_one())) goto err; |
| 123 | if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err; |
| 124 | if (BN_is_one(r1)) break; |
| 125 | if(!BN_GENCB_call(cb, 2, n++)) |
| 126 | goto err; |
| 127 | } |
| 128 | if(!BN_GENCB_call(cb, 3, 0)) |
| 129 | goto err; |
| 130 | for (;;) |
| 131 | { |
| 132 | /* When generating ridiculously small keys, we can get stuck |
| 133 | * continually regenerating the same prime values. Check for |
| 134 | * this and bail if it happens 3 times. */ |
| 135 | unsigned int degenerate = 0; |
| 136 | do |
| 137 | { |
| 138 | if(!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb)) |
| 139 | goto err; |
| 140 | } while((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3)); |
| 141 | if(degenerate == 3) |
| 142 | { |
| 143 | ok = 0; /* we set our own err */ |
| 144 | RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,RSA_R_KEY_SIZE_TOO_SMALL); |
| 145 | goto err; |
| 146 | } |
| 147 | if (!BN_sub(r2,rsa->q,BN_value_one())) goto err; |
| 148 | if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err; |
| 149 | if (BN_is_one(r1)) |
| 150 | break; |
| 151 | if(!BN_GENCB_call(cb, 2, n++)) |
| 152 | goto err; |
| 153 | } |
| 154 | if(!BN_GENCB_call(cb, 3, 1)) |
| 155 | goto err; |
| 156 | if (BN_cmp(rsa->p,rsa->q) < 0) |
| 157 | { |
| 158 | tmp=rsa->p; |
| 159 | rsa->p=rsa->q; |
| 160 | rsa->q=tmp; |
| 161 | } |
| 162 | |
| 163 | /* calculate n */ |
| 164 | if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err; |
| 165 | |
| 166 | /* calculate d */ |
| 167 | if (!BN_sub(r1,rsa->p,BN_value_one())) goto err; /* p-1 */ |
| 168 | if (!BN_sub(r2,rsa->q,BN_value_one())) goto err; /* q-1 */ |
| 169 | if (!BN_mul(r0,r1,r2,ctx)) goto err; /* (p-1)(q-1) */ |
| 170 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 171 | { |
| 172 | pr0 = &local_r0; |
| 173 | BN_with_flags(pr0, r0, BN_FLG_CONSTTIME); |
| 174 | } |
| 175 | else |
| 176 | pr0 = r0; |
| 177 | if (!BN_mod_inverse(rsa->d,rsa->e,pr0,ctx)) goto err; /* d */ |
| 178 | |
| 179 | /* set up d for correct BN_FLG_CONSTTIME flag */ |
| 180 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 181 | { |
| 182 | d = &local_d; |
| 183 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
| 184 | } |
| 185 | else |
| 186 | d = rsa->d; |
| 187 | |
| 188 | /* calculate d mod (p-1) */ |
| 189 | if (!BN_mod(rsa->dmp1,d,r1,ctx)) goto err; |
| 190 | |
| 191 | /* calculate d mod (q-1) */ |
| 192 | if (!BN_mod(rsa->dmq1,d,r2,ctx)) goto err; |
| 193 | |
| 194 | /* calculate inverse of q mod p */ |
| 195 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 196 | { |
| 197 | p = &local_p; |
| 198 | BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); |
| 199 | } |
| 200 | else |
| 201 | p = rsa->p; |
| 202 | if (!BN_mod_inverse(rsa->iqmp,rsa->q,p,ctx)) goto err; |
| 203 | |
| 204 | ok=1; |
| 205 | err: |
| 206 | if (ok == -1) |
| 207 | { |
| 208 | RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,ERR_LIB_BN); |
| 209 | ok=0; |
| 210 | } |
| 211 | if (ctx != NULL) |
| 212 | { |
| 213 | BN_CTX_end(ctx); |
| 214 | BN_CTX_free(ctx); |
| 215 | } |
| 216 | |
| 217 | return ok; |
| 218 | } |
| 219 | |