crypto/rsa/rsa_gen.c

   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 #include <stdio.h>
  60 #include <time.h>
  61 #include "cryptlib.h"
  62 #include "bn.h"
  63 #include "rsa.h"
  64
  65 RSA *RSA_generate_key(bits, e_value, callback,cb_arg)
  66 int bits;
  67 unsigned long e_value;
  68 void (*callback)(P_I_I_P);
  69 char *cb_arg;
  70         {
  71         RSA *rsa=NULL;
  72         BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp;
  73         int bitsp,bitsq,ok= -1,n=0;
  74         BN_CTX *ctx=NULL,*ctx2=NULL;
  75
  76         ctx=BN_CTX_new();
  77         if (ctx == NULL) goto err;
  78         ctx2=BN_CTX_new();
  79         if (ctx2 == NULL) goto err;
  80         r0=ctx->bn[0];
  81         r1=ctx->bn[1];
  82         r2=ctx->bn[2];
  83         r3=ctx->bn[3];
  84         ctx->tos+=4;
  85
  86         bitsp=(bits+1)/2;
  87         bitsq=bits-bitsp;
  88         rsa=RSA_new();
  89         if (rsa == NULL) goto err;
  90
  91         /* set e */
  92         rsa->e=BN_new();
  93         if (rsa->e == NULL) goto err;
  94         if (!BN_set_word(rsa->e,e_value)) goto err;
  95
  96         /* generate p and q */
  97         for (;;)
  98                 {
  99                 rsa->p=BN_generate_prime(bitsp,0,NULL,NULL,callback,cb_arg);
 100                 if (rsa->p == NULL) goto err;
 101                 if (!BN_sub(r2,rsa->p,BN_value_one())) goto err;
 102                 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
 103                 if (BN_is_one(r1)) break;
 104                 if (callback != NULL) callback(2,n++,cb_arg);
 105                 BN_free(rsa->p);
 106                 }
 107         if (callback != NULL) callback(3,0,cb_arg);
 108         for (;;)
 109                 {
 110                 rsa->q=BN_generate_prime(bitsq,0,NULL,NULL,callback,cb_arg);
 111                 if (rsa->q == NULL) goto err;
 112                 if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;
 113                 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
 114                 if (BN_is_one(r1) && (BN_cmp(rsa->p,rsa->q) != 0))
 115                         break;
 116                 if (callback != NULL) callback(2,n++,cb_arg);
 117                 BN_free(rsa->q);
 118                 }
 119         if (callback != NULL) callback(3,1,cb_arg);
 120         if (BN_cmp(rsa->p,rsa->q) < 0)
 121                 {
 122                 tmp=rsa->p;
 123                 rsa->p=rsa->q;
 124                 rsa->q=tmp;
 125                 }
 126
 127         /* calculate n */
 128         rsa->n=BN_new();
 129         if (rsa->n == NULL) goto err;
 130         if (!BN_mul(rsa->n,rsa->p,rsa->q)) goto err;
 131
 132         /* calculate d */
 133         if (!BN_sub(r1,rsa->p,BN_value_one())) goto err;        /* p-1 */
 134         if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;        /* q-1 */
 135         if (!BN_mul(r0,r1,r2)) goto err;        /* (p-1)(q-1) */
 136
 137 /* should not be needed, since gcd(p-1,e) == 1 and gcd(q-1,e) == 1 */
 138 /*      for (;;)
 139                 {
 140                 if (!BN_gcd(r3,r0,rsa->e,ctx)) goto err;
 141                 if (BN_is_one(r3)) break;
 142
 143                 if (1)
 144                         {
 145                         if (!BN_add_word(rsa->e,2L)) goto err;
 146                         continue;
 147                         }
 148                 RSAerr(RSA_F_RSA_GENERATE_KEY,RSA_R_BAD_E_VALUE);
 149                 goto err;
 150                 }
 151 */
 152         rsa->d=(BIGNUM *)BN_mod_inverse(rsa->e,r0,ctx2);        /* d */
 153         if (rsa->d == NULL) goto err;
 154
 155         /* calculate d mod (p-1) */
 156         rsa->dmp1=BN_new();
 157         if (rsa->dmp1 == NULL) goto err;
 158         if (!BN_mod(rsa->dmp1,rsa->d,r1,ctx)) goto err;
 159
 160         /* calculate d mod (q-1) */
 161         rsa->dmq1=BN_new();
 162         if (rsa->dmq1 == NULL) goto err;
 163         if (!BN_mod(rsa->dmq1,rsa->d,r2,ctx)) goto err;
 164
 165         /* calculate inverse of q mod p */
 166         rsa->iqmp=BN_mod_inverse(rsa->q,rsa->p,ctx2);
 167         if (rsa->iqmp == NULL) goto err;
 168
 169         ok=1;
 170 err:
 171         if (ok == -1)
 172                 {
 173                 RSAerr(RSA_F_RSA_GENERATE_KEY,ERR_LIB_BN);
 174                 ok=0;
 175                 }
 176         BN_CTX_free(ctx);
 177         BN_CTX_free(ctx2);
 178
 179         if (!ok)
 180                 {
 181                 if (rsa != NULL) RSA_free(rsa);
 182                 return(NULL);
 183                 }
 184         else
 185                 return(rsa);
 186         }
 187