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(int bits, unsigned long e_value,
  66              void (*callback)(P_I_I_P), char *cb_arg)
  67         {
  68         RSA *rsa=NULL;
  69         BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp;
  70         int bitsp,bitsq,ok= -1,n=0,i;
  71         BN_CTX *ctx=NULL,*ctx2=NULL;
  72
  73         ctx=BN_CTX_new();
  74         if (ctx == NULL) goto err;
  75         ctx2=BN_CTX_new();
  76         if (ctx2 == NULL) goto err;
  77         r0= &(ctx->bn[0]);
  78         r1= &(ctx->bn[1]);
  79         r2= &(ctx->bn[2]);
  80         r3= &(ctx->bn[3]);
  81         ctx->tos+=4;
  82
  83         bitsp=(bits+1)/2;
  84         bitsq=bits-bitsp;
  85         rsa=RSA_new();
  86         if (rsa == NULL) goto err;
  87
  88         /* set e */
  89         rsa->e=BN_new();
  90         if (rsa->e == NULL) goto err;
  91
  92 #if 1
  93         /* The problem is when building with 8, 16, or 32 BN_ULONG,
  94          * unsigned long can be larger */
  95         for (i=0; i<sizeof(unsigned long)*8; i++)
  96                 {
  97                 if (e_value & (1<<i))
  98                         BN_set_bit(rsa->e,i);
  99                 }
 100 #else
 101         if (!BN_set_word(rsa->e,e_value)) goto err;
 102 #endif
 103
 104         /* generate p and q */
 105         for (;;)
 106                 {
 107                 rsa->p=BN_generate_prime(NULL,bitsp,0,NULL,NULL,callback,cb_arg);
 108                 if (rsa->p == NULL) goto err;
 109                 if (!BN_sub(r2,rsa->p,BN_value_one())) goto err;
 110                 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
 111                 if (BN_is_one(r1)) break;
 112                 if (callback != NULL) callback(2,n++,cb_arg);
 113                 BN_free(rsa->p);
 114                 }
 115         if (callback != NULL) callback(3,0,cb_arg);
 116         for (;;)
 117                 {
 118                 rsa->q=BN_generate_prime(NULL,bitsq,0,NULL,NULL,callback,cb_arg);
 119                 if (rsa->q == NULL) goto err;
 120                 if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;
 121                 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
 122                 if (BN_is_one(r1) && (BN_cmp(rsa->p,rsa->q) != 0))
 123                         break;
 124                 if (callback != NULL) callback(2,n++,cb_arg);
 125                 BN_free(rsa->q);
 126                 }
 127         if (callback != NULL) callback(3,1,cb_arg);
 128         if (BN_cmp(rsa->p,rsa->q) < 0)
 129                 {
 130                 tmp=rsa->p;
 131                 rsa->p=rsa->q;
 132                 rsa->q=tmp;
 133                 }
 134
 135         /* calculate n */
 136         rsa->n=BN_new();
 137         if (rsa->n == NULL) goto err;
 138         if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err;
 139
 140         /* calculate d */
 141         if (!BN_sub(r1,rsa->p,BN_value_one())) goto err;        /* p-1 */
 142         if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;        /* q-1 */
 143         if (!BN_mul(r0,r1,r2,ctx)) goto err;    /* (p-1)(q-1) */
 144
 145 /* should not be needed, since gcd(p-1,e) == 1 and gcd(q-1,e) == 1 */
 146 /*      for (;;)
 147                 {
 148                 if (!BN_gcd(r3,r0,rsa->e,ctx)) goto err;
 149                 if (BN_is_one(r3)) break;
 150
 151                 if (1)
 152                         {
 153                         if (!BN_add_word(rsa->e,2L)) goto err;
 154                         continue;
 155                         }
 156                 RSAerr(RSA_F_RSA_GENERATE_KEY,RSA_R_BAD_E_VALUE);
 157                 goto err;
 158                 }
 159 */
 160         rsa->d=(BIGNUM *)BN_mod_inverse(NULL,rsa->e,r0,ctx2);   /* d */
 161         if (rsa->d == NULL) goto err;
 162
 163         /* calculate d mod (p-1) */
 164         rsa->dmp1=BN_new();
 165         if (rsa->dmp1 == NULL) goto err;
 166         if (!BN_mod(rsa->dmp1,rsa->d,r1,ctx)) goto err;
 167
 168         /* calculate d mod (q-1) */
 169         rsa->dmq1=BN_new();
 170         if (rsa->dmq1 == NULL) goto err;
 171         if (!BN_mod(rsa->dmq1,rsa->d,r2,ctx)) goto err;
 172
 173         /* calculate inverse of q mod p */
 174         rsa->iqmp=BN_mod_inverse(NULL,rsa->q,rsa->p,ctx2);
 175         if (rsa->iqmp == NULL) goto err;
 176
 177         ok=1;
 178 err:
 179         if (ok == -1)
 180                 {
 181                 RSAerr(RSA_F_RSA_GENERATE_KEY,ERR_LIB_BN);
 182                 ok=0;
 183                 }
 184         BN_CTX_free(ctx);
 185         BN_CTX_free(ctx2);
 186
 187         if (!ok)
 188                 {
 189                 if (rsa != NULL) RSA_free(rsa);
 190                 return(NULL);
 191                 }
 192         else
 193                 return(rsa);
 194         }
 195