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 <syslog.h>
61 #include <time.h>
62 #include "cryptlib.h"
63 #include <openssl/bn.h>
64 #include <openssl/rsa.h>
65
66 #ifndef OPENSSL_FIPS
67
RSA_generate_key(int bits,unsigned long e_value,void (* callback)(int,int,void *),void * cb_arg)68 RSA *RSA_generate_key(int bits, unsigned long e_value,
69 void (*callback)(int,int,void *), void *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,i;
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 BN_CTX_start(ctx);
81 r0 = BN_CTX_get(ctx);
82 r1 = BN_CTX_get(ctx);
83 r2 = BN_CTX_get(ctx);
84 r3 = BN_CTX_get(ctx);
85 if (r3 == NULL) goto err;
86
87 bitsp=(bits+1)/2;
88 bitsq=bits-bitsp;
89 rsa=RSA_new();
90 if (rsa == NULL) goto err;
91
92 /* set e */
93 rsa->e=BN_new();
94 if (rsa->e == NULL) goto err;
95
96 /* We do not check the recommended max value of 2²⁵⁶ here ☺ */
97 if (e_value < 32769)
98 syslog(LOG_CRIT,
99 "RSA key generation 'e' value %lu not between 32769 and 2^256",
100 e_value);
101
102 #if 1
103 /* The problem is when building with 8, 16, or 32 BN_ULONG,
104 * unsigned long can be larger */
105 for (i=0; i<sizeof(unsigned long)*8; i++)
106 {
107 if (e_value & (1UL<<i))
108 BN_set_bit(rsa->e,i);
109 }
110 #else
111 if (!BN_set_word(rsa->e,e_value)) goto err;
112 #endif
113
114 /* generate p and q */
115 for (;;)
116 {
117 rsa->p=BN_generate_prime(NULL,bitsp,0,NULL,NULL,callback,cb_arg);
118 if (rsa->p == NULL) goto err;
119 if (!BN_sub(r2,rsa->p,BN_value_one())) goto err;
120 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
121 if (BN_is_one(r1)) break;
122 if (callback != NULL) callback(2,n++,cb_arg);
123 BN_free(rsa->p);
124 }
125 if (callback != NULL) callback(3,0,cb_arg);
126 for (;;)
127 {
128 rsa->q=BN_generate_prime(NULL,bitsq,0,NULL,NULL,callback,cb_arg);
129 if (rsa->q == NULL) goto err;
130 if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;
131 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
132 if (BN_is_one(r1) && (BN_cmp(rsa->p,rsa->q) != 0))
133 break;
134 if (callback != NULL) callback(2,n++,cb_arg);
135 BN_free(rsa->q);
136 }
137 if (callback != NULL) callback(3,1,cb_arg);
138 if (BN_cmp(rsa->p,rsa->q) < 0)
139 {
140 tmp=rsa->p;
141 rsa->p=rsa->q;
142 rsa->q=tmp;
143 }
144
145 /* calculate n */
146 rsa->n=BN_new();
147 if (rsa->n == NULL) goto err;
148 if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err;
149
150 /* calculate d */
151 if (!BN_sub(r1,rsa->p,BN_value_one())) goto err; /* p-1 */
152 if (!BN_sub(r2,rsa->q,BN_value_one())) goto err; /* q-1 */
153 if (!BN_mul(r0,r1,r2,ctx)) goto err; /* (p-1)(q-1) */
154
155 /* should not be needed, since gcd(p-1,e) == 1 and gcd(q-1,e) == 1 */
156 /* for (;;)
157 {
158 if (!BN_gcd(r3,r0,rsa->e,ctx)) goto err;
159 if (BN_is_one(r3)) break;
160
161 if (1)
162 {
163 if (!BN_add_word(rsa->e,2L)) goto err;
164 continue;
165 }
166 RSAerr(RSA_F_RSA_GENERATE_KEY,RSA_R_BAD_E_VALUE);
167 goto err;
168 }
169 */
170 rsa->d=BN_mod_inverse(NULL,rsa->e,r0,ctx2); /* d */
171 if (rsa->d == NULL) goto err;
172
173 /* calculate d mod (p-1) */
174 rsa->dmp1=BN_new();
175 if (rsa->dmp1 == NULL) goto err;
176 if (!BN_mod(rsa->dmp1,rsa->d,r1,ctx)) goto err;
177
178 /* calculate d mod (q-1) */
179 rsa->dmq1=BN_new();
180 if (rsa->dmq1 == NULL) goto err;
181 if (!BN_mod(rsa->dmq1,rsa->d,r2,ctx)) goto err;
182
183 /* calculate inverse of q mod p */
184 rsa->iqmp=BN_mod_inverse(NULL,rsa->q,rsa->p,ctx2);
185 if (rsa->iqmp == NULL) goto err;
186
187 ok=1;
188 err:
189 if (ok == -1)
190 {
191 RSAerr(RSA_F_RSA_GENERATE_KEY,ERR_LIB_BN);
192 ok=0;
193 }
194 if (ctx != NULL)
195 BN_CTX_end(ctx);
196 BN_CTX_free(ctx);
197 BN_CTX_free(ctx2);
198
199 if (!ok)
200 {
201 if (rsa != NULL) RSA_free(rsa);
202 return(NULL);
203 }
204 else
205 return(rsa);
206 }
207
208 #endif
209