rsa_gen.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/* 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.]
*/
#include <stdio.h>
#include <time.h>
#include "cryptlib.h"
#include <openssl/bn.h>
#include <openssl/rsa.h>
RSA *RSA_generate_key(int bits, unsigned long e_value,
void (*callback)(int,int,void *), void *cb_arg)
{
RSA *rsa=NULL;
BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp;
int bitsp,bitsq,ok= -1,n=0,i;
BN_CTX *ctx=NULL,*ctx2=NULL;
ctx=BN_CTX_new();
if (ctx == NULL) goto err;
ctx2=BN_CTX_new();
if (ctx2 == 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;
rsa=RSA_new();
if (rsa == NULL) goto err;
/* set e */
rsa->e=BN_new();
if (rsa->e == NULL) goto err;
#if 1
/* The problem is when building with 8, 16, or 32 BN_ULONG,
* unsigned long can be larger */
for (i=0; i<sizeof(unsigned long)*8; i++)
{
if (e_value & (1UL<<i))
BN_set_bit(rsa->e,i);
}
#else
if (!BN_set_word(rsa->e,e_value)) goto err;
#endif
/* generate p and q */
for (;;)
{
rsa->p=BN_generate_prime(NULL,bitsp,0,NULL,NULL,callback,cb_arg);
if (rsa->p == NULL) 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 (callback != NULL) callback(2,n++,cb_arg);
BN_free(rsa->p);
}
if (callback != NULL) callback(3,0,cb_arg);
for (;;)
{
rsa->q=BN_generate_prime(NULL,bitsq,0,NULL,NULL,callback,cb_arg);
if (rsa->q == NULL) 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) && (BN_cmp(rsa->p,rsa->q) != 0))
break;
if (callback != NULL) callback(2,n++,cb_arg);
BN_free(rsa->q);
}
if (callback != NULL) callback(3,1,cb_arg);
if (BN_cmp(rsa->p,rsa->q) < 0)
{
tmp=rsa->p;
rsa->p=rsa->q;
rsa->q=tmp;
}
/* calculate n */
rsa->n=BN_new();
if (rsa->n == NULL) goto err;
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) */
/* should not be needed, since gcd(p-1,e) == 1 and gcd(q-1,e) == 1 */
/* for (;;)
{
if (!BN_gcd(r3,r0,rsa->e,ctx)) goto err;
if (BN_is_one(r3)) break;
if (1)
{
if (!BN_add_word(rsa->e,2L)) goto err;
continue;
}
RSAerr(RSA_F_RSA_GENERATE_KEY,RSA_R_BAD_E_VALUE);
goto err;
}
*/
rsa->d=BN_mod_inverse(NULL,rsa->e,r0,ctx2); /* d */
if (rsa->d == NULL) goto err;
/* calculate d mod (p-1) */
rsa->dmp1=BN_new();
if (rsa->dmp1 == NULL) goto err;
if (!BN_mod(rsa->dmp1,rsa->d,r1,ctx)) goto err;
/* calculate d mod (q-1) */
rsa->dmq1=BN_new();
if (rsa->dmq1 == NULL) goto err;
if (!BN_mod(rsa->dmq1,rsa->d,r2,ctx)) goto err;
/* calculate inverse of q mod p */
rsa->iqmp=BN_mod_inverse(NULL,rsa->q,rsa->p,ctx2);
if (rsa->iqmp == NULL) goto err;
ok=1;
err:
if (ok == -1)
{
RSAerr(RSA_F_RSA_GENERATE_KEY,ERR_LIB_BN);
ok=0;
}
BN_CTX_end(ctx);
BN_CTX_free(ctx);
BN_CTX_free(ctx2);
if (!ok)
{
if (rsa != NULL) RSA_free(rsa);
return(NULL);
}
else
return(rsa);
}