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Commit | Line | Data |
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0f113f3e | 1 | /* |
1212818e | 2 | * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved. |
7b1a0451 | 3 | * |
367ace68 | 4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
4f22f405 RS |
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 | |
7b1a0451 DSH |
8 | */ |
9 | ||
10 | #include <stdio.h> | |
11 | #include <openssl/bn.h> | |
706457b7 | 12 | #include "bn_local.h" |
7b1a0451 DSH |
13 | |
14 | /* X9.31 routines for prime derivation */ | |
15 | ||
0f113f3e MC |
16 | /* |
17 | * X9.31 prime derivation. This is used to generate the primes pi (p1, p2, | |
18 | * q1, q2) from a parameter Xpi by checking successive odd integers. | |
7b1a0451 DSH |
19 | */ |
20 | ||
21 | static int bn_x931_derive_pi(BIGNUM *pi, const BIGNUM *Xpi, BN_CTX *ctx, | |
0f113f3e MC |
22 | BN_GENCB *cb) |
23 | { | |
748e8530 | 24 | int i = 0, is_prime; |
0f113f3e MC |
25 | if (!BN_copy(pi, Xpi)) |
26 | return 0; | |
27 | if (!BN_is_odd(pi) && !BN_add_word(pi, 1)) | |
28 | return 0; | |
29 | for (;;) { | |
30 | i++; | |
31 | BN_GENCB_call(cb, 0, i); | |
0d4fb843 | 32 | /* NB 27 MR is specified in X9.31 */ |
748e8530 DB |
33 | is_prime = BN_is_prime_fasttest_ex(pi, 27, ctx, 1, cb); |
34 | if (is_prime < 0) | |
35 | return 0; | |
36 | if (is_prime) | |
0f113f3e MC |
37 | break; |
38 | if (!BN_add_word(pi, 2)) | |
39 | return 0; | |
40 | } | |
41 | BN_GENCB_call(cb, 2, i); | |
42 | return 1; | |
43 | } | |
44 | ||
45 | /* | |
46 | * This is the main X9.31 prime derivation function. From parameters Xp1, Xp2 | |
47 | * and Xp derive the prime p. If the parameters p1 or p2 are not NULL they | |
48 | * will be returned too: this is needed for testing. | |
7b1a0451 DSH |
49 | */ |
50 | ||
51 | int BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2, | |
0f113f3e MC |
52 | const BIGNUM *Xp, const BIGNUM *Xp1, |
53 | const BIGNUM *Xp2, const BIGNUM *e, BN_CTX *ctx, | |
54 | BN_GENCB *cb) | |
55 | { | |
56 | int ret = 0; | |
7b1a0451 | 57 | |
0f113f3e | 58 | BIGNUM *t, *p1p2, *pm1; |
7b1a0451 | 59 | |
0f113f3e MC |
60 | /* Only even e supported */ |
61 | if (!BN_is_odd(e)) | |
62 | return 0; | |
7b1a0451 | 63 | |
0f113f3e | 64 | BN_CTX_start(ctx); |
edea42c6 | 65 | if (p1 == NULL) |
0f113f3e | 66 | p1 = BN_CTX_get(ctx); |
7b1a0451 | 67 | |
edea42c6 | 68 | if (p2 == NULL) |
0f113f3e | 69 | p2 = BN_CTX_get(ctx); |
7b1a0451 | 70 | |
0f113f3e | 71 | t = BN_CTX_get(ctx); |
7b1a0451 | 72 | |
0f113f3e | 73 | p1p2 = BN_CTX_get(ctx); |
7b1a0451 | 74 | |
0f113f3e | 75 | pm1 = BN_CTX_get(ctx); |
7b1a0451 | 76 | |
4d94bd36 MC |
77 | if (pm1 == NULL) |
78 | goto err; | |
79 | ||
0f113f3e MC |
80 | if (!bn_x931_derive_pi(p1, Xp1, ctx, cb)) |
81 | goto err; | |
7b1a0451 | 82 | |
0f113f3e MC |
83 | if (!bn_x931_derive_pi(p2, Xp2, ctx, cb)) |
84 | goto err; | |
7b1a0451 | 85 | |
0f113f3e MC |
86 | if (!BN_mul(p1p2, p1, p2, ctx)) |
87 | goto err; | |
7b1a0451 | 88 | |
0f113f3e | 89 | /* First set p to value of Rp */ |
7b1a0451 | 90 | |
0f113f3e MC |
91 | if (!BN_mod_inverse(p, p2, p1, ctx)) |
92 | goto err; | |
7b1a0451 | 93 | |
0f113f3e MC |
94 | if (!BN_mul(p, p, p2, ctx)) |
95 | goto err; | |
7b1a0451 | 96 | |
0f113f3e MC |
97 | if (!BN_mod_inverse(t, p1, p2, ctx)) |
98 | goto err; | |
7b1a0451 | 99 | |
0f113f3e MC |
100 | if (!BN_mul(t, t, p1, ctx)) |
101 | goto err; | |
7b1a0451 | 102 | |
0f113f3e MC |
103 | if (!BN_sub(p, p, t)) |
104 | goto err; | |
7b1a0451 | 105 | |
0f113f3e MC |
106 | if (p->neg && !BN_add(p, p, p1p2)) |
107 | goto err; | |
7b1a0451 | 108 | |
0f113f3e | 109 | /* p now equals Rp */ |
7b1a0451 | 110 | |
0f113f3e MC |
111 | if (!BN_mod_sub(p, p, Xp, p1p2, ctx)) |
112 | goto err; | |
7b1a0451 | 113 | |
0f113f3e MC |
114 | if (!BN_add(p, p, Xp)) |
115 | goto err; | |
7b1a0451 | 116 | |
0f113f3e | 117 | /* p now equals Yp0 */ |
7b1a0451 | 118 | |
0f113f3e MC |
119 | for (;;) { |
120 | int i = 1; | |
121 | BN_GENCB_call(cb, 0, i++); | |
122 | if (!BN_copy(pm1, p)) | |
123 | goto err; | |
124 | if (!BN_sub_word(pm1, 1)) | |
125 | goto err; | |
126 | if (!BN_gcd(t, pm1, e, ctx)) | |
127 | goto err; | |
748e8530 | 128 | if (BN_is_one(t)) { |
0f113f3e MC |
129 | /* |
130 | * X9.31 specifies 8 MR and 1 Lucas test or any prime test | |
131 | * offering similar or better guarantees 50 MR is considerably | |
132 | * better. | |
133 | */ | |
748e8530 DB |
134 | int r = BN_is_prime_fasttest_ex(p, 50, ctx, 1, cb); |
135 | if (r < 0) | |
136 | goto err; | |
137 | if (r) | |
138 | break; | |
139 | } | |
0f113f3e MC |
140 | if (!BN_add(p, p, p1p2)) |
141 | goto err; | |
142 | } | |
7b1a0451 | 143 | |
0f113f3e | 144 | BN_GENCB_call(cb, 3, 0); |
7b1a0451 | 145 | |
0f113f3e | 146 | ret = 1; |
7b1a0451 | 147 | |
0f113f3e | 148 | err: |
7b1a0451 | 149 | |
0f113f3e | 150 | BN_CTX_end(ctx); |
7b1a0451 | 151 | |
0f113f3e MC |
152 | return ret; |
153 | } | |
7b1a0451 | 154 | |
0f113f3e MC |
155 | /* |
156 | * Generate pair of parameters Xp, Xq for X9.31 prime generation. Note: nbits | |
157 | * parameter is sum of number of bits in both. | |
7b1a0451 DSH |
158 | */ |
159 | ||
160 | int BN_X931_generate_Xpq(BIGNUM *Xp, BIGNUM *Xq, int nbits, BN_CTX *ctx) | |
0f113f3e MC |
161 | { |
162 | BIGNUM *t; | |
163 | int i; | |
164 | /* | |
165 | * Number of bits for each prime is of the form 512+128s for s = 0, 1, | |
166 | * ... | |
167 | */ | |
168 | if ((nbits < 1024) || (nbits & 0xff)) | |
169 | return 0; | |
170 | nbits >>= 1; | |
171 | /* | |
172 | * The random value Xp must be between sqrt(2) * 2^(nbits-1) and 2^nbits | |
173 | * - 1. By setting the top two bits we ensure that the lower bound is | |
174 | * exceeded. | |
175 | */ | |
2934be91 | 176 | if (!BN_priv_rand_ex(Xp, nbits, BN_RAND_TOP_TWO, BN_RAND_BOTTOM_ANY, ctx)) |
3f6c7691 | 177 | goto err; |
0f113f3e MC |
178 | |
179 | BN_CTX_start(ctx); | |
180 | t = BN_CTX_get(ctx); | |
5419dadd BE |
181 | if (t == NULL) |
182 | goto err; | |
0f113f3e MC |
183 | |
184 | for (i = 0; i < 1000; i++) { | |
2934be91 MC |
185 | if (!BN_priv_rand_ex(Xq, nbits, BN_RAND_TOP_TWO, BN_RAND_BOTTOM_ANY, |
186 | ctx)) | |
3f6c7691 | 187 | goto err; |
6bcfcf16 | 188 | |
0f113f3e | 189 | /* Check that |Xp - Xq| > 2^(nbits - 100) */ |
6bcfcf16 P |
190 | if (!BN_sub(t, Xp, Xq)) |
191 | goto err; | |
0f113f3e MC |
192 | if (BN_num_bits(t) > (nbits - 100)) |
193 | break; | |
194 | } | |
195 | ||
196 | BN_CTX_end(ctx); | |
197 | ||
198 | if (i < 1000) | |
199 | return 1; | |
200 | ||
201 | return 0; | |
202 | ||
3f6c7691 AG |
203 | err: |
204 | BN_CTX_end(ctx); | |
205 | return 0; | |
0f113f3e MC |
206 | } |
207 | ||
208 | /* | |
209 | * Generate primes using X9.31 algorithm. Of the values p, p1, p2, Xp1 and | |
210 | * Xp2 only 'p' needs to be non-NULL. If any of the others are not NULL the | |
211 | * relevant parameter will be stored in it. Due to the fact that |Xp - Xq| > | |
212 | * 2^(nbits - 100) must be satisfied Xp and Xq are generated using the | |
213 | * previous function and supplied as input. | |
7b1a0451 DSH |
214 | */ |
215 | ||
216 | int BN_X931_generate_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2, | |
0f113f3e MC |
217 | BIGNUM *Xp1, BIGNUM *Xp2, |
218 | const BIGNUM *Xp, | |
219 | const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb) | |
220 | { | |
221 | int ret = 0; | |
7b1a0451 | 222 | |
0f113f3e | 223 | BN_CTX_start(ctx); |
5419dadd | 224 | if (Xp1 == NULL) |
0f113f3e | 225 | Xp1 = BN_CTX_get(ctx); |
5419dadd | 226 | if (Xp2 == NULL) |
0f113f3e | 227 | Xp2 = BN_CTX_get(ctx); |
5419dadd BE |
228 | if (Xp1 == NULL || Xp2 == NULL) |
229 | goto error; | |
7b1a0451 | 230 | |
2934be91 | 231 | if (!BN_priv_rand_ex(Xp1, 101, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY, ctx)) |
0f113f3e | 232 | goto error; |
2934be91 | 233 | if (!BN_priv_rand_ex(Xp2, 101, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY, ctx)) |
0f113f3e MC |
234 | goto error; |
235 | if (!BN_X931_derive_prime_ex(p, p1, p2, Xp, Xp1, Xp2, e, ctx, cb)) | |
236 | goto error; | |
7b1a0451 | 237 | |
0f113f3e | 238 | ret = 1; |
7b1a0451 | 239 | |
0f113f3e MC |
240 | error: |
241 | BN_CTX_end(ctx); | |
7b1a0451 | 242 | |
0f113f3e | 243 | return ret; |
7b1a0451 | 244 | |
0f113f3e | 245 | } |