rsa_gen.c revision 59191
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 <openssl/bn.h>
63#include <openssl/rsa.h>
64
65RSA *RSA_generate_key(int bits, unsigned long e_value,
66	     void (*callback)(int,int,void *), void *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	BN_CTX_start(ctx);
78	r0 = BN_CTX_get(ctx);
79	r1 = BN_CTX_get(ctx);
80	r2 = BN_CTX_get(ctx);
81	r3 = BN_CTX_get(ctx);
82	if (r3 == NULL) goto err;
83
84	bitsp=(bits+1)/2;
85	bitsq=bits-bitsp;
86	rsa=RSA_new();
87	if (rsa == NULL) goto err;
88
89	/* set e */
90	rsa->e=BN_new();
91	if (rsa->e == NULL) goto err;
92
93#if 1
94	/* The problem is when building with 8, 16, or 32 BN_ULONG,
95	 * unsigned long can be larger */
96	for (i=0; i<sizeof(unsigned long)*8; i++)
97		{
98		if (e_value & (1<<i))
99			BN_set_bit(rsa->e,i);
100		}
101#else
102	if (!BN_set_word(rsa->e,e_value)) goto err;
103#endif
104
105	/* generate p and q */
106	for (;;)
107		{
108		rsa->p=BN_generate_prime(NULL,bitsp,0,NULL,NULL,callback,cb_arg);
109		if (rsa->p == NULL) goto err;
110		if (!BN_sub(r2,rsa->p,BN_value_one())) goto err;
111		if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
112		if (BN_is_one(r1)) break;
113		if (callback != NULL) callback(2,n++,cb_arg);
114		BN_free(rsa->p);
115		}
116	if (callback != NULL) callback(3,0,cb_arg);
117	for (;;)
118		{
119		rsa->q=BN_generate_prime(NULL,bitsq,0,NULL,NULL,callback,cb_arg);
120		if (rsa->q == NULL) goto err;
121		if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;
122		if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
123		if (BN_is_one(r1) && (BN_cmp(rsa->p,rsa->q) != 0))
124			break;
125		if (callback != NULL) callback(2,n++,cb_arg);
126		BN_free(rsa->q);
127		}
128	if (callback != NULL) callback(3,1,cb_arg);
129	if (BN_cmp(rsa->p,rsa->q) < 0)
130		{
131		tmp=rsa->p;
132		rsa->p=rsa->q;
133		rsa->q=tmp;
134		}
135
136	/* calculate n */
137	rsa->n=BN_new();
138	if (rsa->n == NULL) goto err;
139	if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err;
140
141	/* calculate d */
142	if (!BN_sub(r1,rsa->p,BN_value_one())) goto err;	/* p-1 */
143	if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;	/* q-1 */
144	if (!BN_mul(r0,r1,r2,ctx)) goto err;	/* (p-1)(q-1) */
145
146/* should not be needed, since gcd(p-1,e) == 1 and gcd(q-1,e) == 1 */
147/*	for (;;)
148		{
149		if (!BN_gcd(r3,r0,rsa->e,ctx)) goto err;
150		if (BN_is_one(r3)) break;
151
152		if (1)
153			{
154			if (!BN_add_word(rsa->e,2L)) goto err;
155			continue;
156			}
157		RSAerr(RSA_F_RSA_GENERATE_KEY,RSA_R_BAD_E_VALUE);
158		goto err;
159		}
160*/
161	rsa->d=BN_mod_inverse(NULL,rsa->e,r0,ctx2);	/* d */
162	if (rsa->d == NULL) goto err;
163
164	/* calculate d mod (p-1) */
165	rsa->dmp1=BN_new();
166	if (rsa->dmp1 == NULL) goto err;
167	if (!BN_mod(rsa->dmp1,rsa->d,r1,ctx)) goto err;
168
169	/* calculate d mod (q-1) */
170	rsa->dmq1=BN_new();
171	if (rsa->dmq1 == NULL) goto err;
172	if (!BN_mod(rsa->dmq1,rsa->d,r2,ctx)) goto err;
173
174	/* calculate inverse of q mod p */
175	rsa->iqmp=BN_mod_inverse(NULL,rsa->q,rsa->p,ctx2);
176	if (rsa->iqmp == NULL) goto err;
177
178	ok=1;
179err:
180	if (ok == -1)
181		{
182		RSAerr(RSA_F_RSA_GENERATE_KEY,ERR_LIB_BN);
183		ok=0;
184		}
185	BN_CTX_end(ctx);
186	BN_CTX_free(ctx);
187	BN_CTX_free(ctx2);
188
189	if (!ok)
190		{
191		if (rsa != NULL) RSA_free(rsa);
192		return(NULL);
193		}
194	else
195		return(rsa);
196	}
197
198