1 /*
2 * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /*
11 * RSA low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #define OPENSSL_SUPPRESS_DEPRECATED
15
16 #include <stdio.h>
17 #include <string.h>
18 #include <time.h>
19 #include <openssl/err.h>
20 #include <openssl/bn.h>
21 #include "rsa_local.h"
22
23 /* X9.31 RSA key derivation and generation */
24
RSA_X931_derive_ex(RSA * rsa,BIGNUM * p1,BIGNUM * p2,BIGNUM * q1,BIGNUM * q2,const BIGNUM * Xp1,const BIGNUM * Xp2,const BIGNUM * Xp,const BIGNUM * Xq1,const BIGNUM * Xq2,const BIGNUM * Xq,const BIGNUM * e,BN_GENCB * cb)25 int RSA_X931_derive_ex(RSA *rsa, BIGNUM *p1, BIGNUM *p2, BIGNUM *q1,
26 BIGNUM *q2, const BIGNUM *Xp1, const BIGNUM *Xp2,
27 const BIGNUM *Xp, const BIGNUM *Xq1, const BIGNUM *Xq2,
28 const BIGNUM *Xq, const BIGNUM *e, BN_GENCB *cb)
29 {
30 BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL;
31 BN_CTX *ctx = NULL, *ctx2 = NULL;
32 int ret = 0;
33
34 if (rsa == NULL)
35 goto err;
36
37 ctx = BN_CTX_new_ex(rsa->libctx);
38 if (ctx == NULL)
39 goto err;
40 BN_CTX_start(ctx);
41
42 r0 = BN_CTX_get(ctx);
43 r1 = BN_CTX_get(ctx);
44 r2 = BN_CTX_get(ctx);
45 r3 = BN_CTX_get(ctx);
46
47 if (r3 == NULL)
48 goto err;
49 if (!rsa->e) {
50 rsa->e = BN_dup(e);
51 if (!rsa->e)
52 goto err;
53 } else {
54 e = rsa->e;
55 }
56
57 /*
58 * If not all parameters present only calculate what we can. This allows
59 * test programs to output selective parameters.
60 */
61
62 if (Xp && rsa->p == NULL) {
63 rsa->p = BN_new();
64 if (rsa->p == NULL)
65 goto err;
66
67 if (!BN_X931_derive_prime_ex(rsa->p, p1, p2,
68 Xp, Xp1, Xp2, e, ctx, cb))
69 goto err;
70 }
71
72 if (Xq && rsa->q == NULL) {
73 rsa->q = BN_new();
74 if (rsa->q == NULL)
75 goto err;
76 if (!BN_X931_derive_prime_ex(rsa->q, q1, q2,
77 Xq, Xq1, Xq2, e, ctx, cb))
78 goto err;
79 }
80
81 if (rsa->p == NULL || rsa->q == NULL) {
82 BN_CTX_end(ctx);
83 BN_CTX_free(ctx);
84 return 2;
85 }
86
87 /*
88 * Since both primes are set we can now calculate all remaining
89 * components.
90 */
91
92 /* calculate n */
93 rsa->n = BN_new();
94 if (rsa->n == NULL)
95 goto err;
96 if (!BN_mul(rsa->n, rsa->p, rsa->q, ctx))
97 goto err;
98
99 /* calculate d */
100 if (!BN_sub(r1, rsa->p, BN_value_one()))
101 goto err; /* p-1 */
102 if (!BN_sub(r2, rsa->q, BN_value_one()))
103 goto err; /* q-1 */
104 if (!BN_mul(r0, r1, r2, ctx))
105 goto err; /* (p-1)(q-1) */
106
107 if (!BN_gcd(r3, r1, r2, ctx))
108 goto err;
109
110 if (!BN_div(r0, NULL, r0, r3, ctx))
111 goto err; /* LCM((p-1)(q-1)) */
112
113 ctx2 = BN_CTX_new();
114 if (ctx2 == NULL)
115 goto err;
116
117 rsa->d = BN_mod_inverse(NULL, rsa->e, r0, ctx2); /* d */
118 if (rsa->d == NULL)
119 goto err;
120
121 /* calculate d mod (p-1) */
122 rsa->dmp1 = BN_new();
123 if (rsa->dmp1 == NULL)
124 goto err;
125 if (!BN_mod(rsa->dmp1, rsa->d, r1, ctx))
126 goto err;
127
128 /* calculate d mod (q-1) */
129 rsa->dmq1 = BN_new();
130 if (rsa->dmq1 == NULL)
131 goto err;
132 if (!BN_mod(rsa->dmq1, rsa->d, r2, ctx))
133 goto err;
134
135 /* calculate inverse of q mod p */
136 rsa->iqmp = BN_mod_inverse(NULL, rsa->q, rsa->p, ctx2);
137 if (rsa->iqmp == NULL)
138 goto err;
139
140 rsa->dirty_cnt++;
141 ret = 1;
142 err:
143 BN_CTX_end(ctx);
144 BN_CTX_free(ctx);
145 BN_CTX_free(ctx2);
146
147 return ret;
148 }
149
RSA_X931_generate_key_ex(RSA * rsa,int bits,const BIGNUM * e,BN_GENCB * cb)150 int RSA_X931_generate_key_ex(RSA *rsa, int bits, const BIGNUM *e,
151 BN_GENCB *cb)
152 {
153 int ok = 0;
154 BIGNUM *Xp = NULL, *Xq = NULL;
155 BN_CTX *ctx = NULL;
156
157 ctx = BN_CTX_new_ex(rsa->libctx);
158 if (ctx == NULL)
159 goto error;
160
161 BN_CTX_start(ctx);
162 Xp = BN_CTX_get(ctx);
163 Xq = BN_CTX_get(ctx);
164 if (Xq == NULL)
165 goto error;
166 if (!BN_X931_generate_Xpq(Xp, Xq, bits, ctx))
167 goto error;
168
169 rsa->p = BN_new();
170 rsa->q = BN_new();
171 if (rsa->p == NULL || rsa->q == NULL)
172 goto error;
173
174 /* Generate two primes from Xp, Xq */
175
176 if (!BN_X931_generate_prime_ex(rsa->p, NULL, NULL, NULL, NULL, Xp,
177 e, ctx, cb))
178 goto error;
179
180 if (!BN_X931_generate_prime_ex(rsa->q, NULL, NULL, NULL, NULL, Xq,
181 e, ctx, cb))
182 goto error;
183
184 /*
185 * Since rsa->p and rsa->q are valid this call will just derive remaining
186 * RSA components.
187 */
188
189 if (!RSA_X931_derive_ex(rsa, NULL, NULL, NULL, NULL,
190 NULL, NULL, NULL, NULL, NULL, NULL, e, cb))
191 goto error;
192
193 rsa->dirty_cnt++;
194 ok = 1;
195
196 error:
197 BN_CTX_end(ctx);
198 BN_CTX_free(ctx);
199
200 if (ok)
201 return 1;
202
203 return 0;
204
205 }
206
