source: EcnlProtoTool/trunk/openssl-1.1.0e/crypto/dsa/dsa_ossl.c@ 331

Last change on this file since 331 was 331, checked in by coas-nagasima, 6 years ago

prototoolに関連するプロジェクトをnewlibからmuslを使うよう変更・更新
ntshellをnewlibの下位の実装から、muslのsyscallの実装に変更・更新
以下のOSSをアップデート
・mruby-1.3.0
・musl-1.1.18
・onigmo-6.1.3
・tcc-0.9.27
以下のOSSを追加
・openssl-1.1.0e
・curl-7.57.0
・zlib-1.2.11
以下のmrbgemsを追加
・iij/mruby-digest
・iij/mruby-env
・iij/mruby-errno
・iij/mruby-iijson
・iij/mruby-ipaddr
・iij/mruby-mock
・iij/mruby-require
・iij/mruby-tls-openssl
  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/x-csrc
File size: 8.8 KB
Line 
1/*
2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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/* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
11
12#include <stdio.h>
13#include "internal/cryptlib.h"
14#include <openssl/bn.h>
15#include <openssl/sha.h>
16#include "dsa_locl.h"
17#include <openssl/asn1.h>
18
19static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
20static int dsa_sign_setup_no_digest(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
21 BIGNUM **rp);
22static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
23 BIGNUM **rp, const unsigned char *dgst, int dlen);
24static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
25 DSA_SIG *sig, DSA *dsa);
26static int dsa_init(DSA *dsa);
27static int dsa_finish(DSA *dsa);
28
29static DSA_METHOD openssl_dsa_meth = {
30 "OpenSSL DSA method",
31 dsa_do_sign,
32 dsa_sign_setup_no_digest,
33 dsa_do_verify,
34 NULL, /* dsa_mod_exp, */
35 NULL, /* dsa_bn_mod_exp, */
36 dsa_init,
37 dsa_finish,
38 DSA_FLAG_FIPS_METHOD,
39 NULL,
40 NULL,
41 NULL
42};
43
44const DSA_METHOD *DSA_OpenSSL(void)
45{
46 return &openssl_dsa_meth;
47}
48
49static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
50{
51 BIGNUM *kinv = NULL;
52 BIGNUM *m;
53 BIGNUM *xr;
54 BN_CTX *ctx = NULL;
55 int reason = ERR_R_BN_LIB;
56 DSA_SIG *ret = NULL;
57 int rv = 0;
58
59 m = BN_new();
60 xr = BN_new();
61 if (m == NULL || xr == NULL)
62 goto err;
63
64 if (!dsa->p || !dsa->q || !dsa->g) {
65 reason = DSA_R_MISSING_PARAMETERS;
66 goto err;
67 }
68
69 ret = DSA_SIG_new();
70 if (ret == NULL)
71 goto err;
72 ret->r = BN_new();
73 ret->s = BN_new();
74 if (ret->r == NULL || ret->s == NULL)
75 goto err;
76
77 ctx = BN_CTX_new();
78 if (ctx == NULL)
79 goto err;
80 redo:
81 if (!dsa_sign_setup(dsa, ctx, &kinv, &ret->r, dgst, dlen))
82 goto err;
83
84 if (dlen > BN_num_bytes(dsa->q))
85 /*
86 * if the digest length is greater than the size of q use the
87 * BN_num_bits(dsa->q) leftmost bits of the digest, see fips 186-3,
88 * 4.2
89 */
90 dlen = BN_num_bytes(dsa->q);
91 if (BN_bin2bn(dgst, dlen, m) == NULL)
92 goto err;
93
94 /* Compute s = inv(k) (m + xr) mod q */
95 if (!BN_mod_mul(xr, dsa->priv_key, ret->r, dsa->q, ctx))
96 goto err; /* s = xr */
97 if (!BN_add(ret->s, xr, m))
98 goto err; /* s = m + xr */
99 if (BN_cmp(ret->s, dsa->q) > 0)
100 if (!BN_sub(ret->s, ret->s, dsa->q))
101 goto err;
102 if (!BN_mod_mul(ret->s, ret->s, kinv, dsa->q, ctx))
103 goto err;
104
105 /*
106 * Redo if r or s is zero as required by FIPS 186-3: this is very
107 * unlikely.
108 */
109 if (BN_is_zero(ret->r) || BN_is_zero(ret->s))
110 goto redo;
111
112 rv = 1;
113
114 err:
115 if (rv == 0) {
116 DSAerr(DSA_F_DSA_DO_SIGN, reason);
117 DSA_SIG_free(ret);
118 ret = NULL;
119 }
120 BN_CTX_free(ctx);
121 BN_clear_free(m);
122 BN_clear_free(xr);
123 BN_clear_free(kinv);
124 return ret;
125}
126
127static int dsa_sign_setup_no_digest(DSA *dsa, BN_CTX *ctx_in,
128 BIGNUM **kinvp, BIGNUM **rp)
129{
130 return dsa_sign_setup(dsa, ctx_in, kinvp, rp, NULL, 0);
131}
132
133static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
134 BIGNUM **kinvp, BIGNUM **rp,
135 const unsigned char *dgst, int dlen)
136{
137 BN_CTX *ctx = NULL;
138 BIGNUM *k, *kinv = NULL, *r = *rp;
139 int ret = 0;
140
141 if (!dsa->p || !dsa->q || !dsa->g) {
142 DSAerr(DSA_F_DSA_SIGN_SETUP, DSA_R_MISSING_PARAMETERS);
143 return 0;
144 }
145
146 k = BN_new();
147 if (k == NULL)
148 goto err;
149
150 if (ctx_in == NULL) {
151 if ((ctx = BN_CTX_new()) == NULL)
152 goto err;
153 } else
154 ctx = ctx_in;
155
156 /* Get random k */
157 do {
158 if (dgst != NULL) {
159 /*
160 * We calculate k from SHA512(private_key + H(message) + random).
161 * This protects the private key from a weak PRNG.
162 */
163 if (!BN_generate_dsa_nonce(k, dsa->q, dsa->priv_key, dgst,
164 dlen, ctx))
165 goto err;
166 } else if (!BN_rand_range(k, dsa->q))
167 goto err;
168 } while (BN_is_zero(k));
169
170 BN_set_flags(k, BN_FLG_CONSTTIME);
171
172 if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {
173 if (!BN_MONT_CTX_set_locked(&dsa->method_mont_p,
174 dsa->lock, dsa->p, ctx))
175 goto err;
176 }
177
178 /* Compute r = (g^k mod p) mod q */
179
180 /*
181 * We do not want timing information to leak the length of k, so we
182 * compute g^k using an equivalent exponent of fixed length. (This
183 * is a kludge that we need because the BN_mod_exp_mont() does not
184 * let us specify the desired timing behaviour.)
185 */
186
187 if (!BN_add(k, k, dsa->q))
188 goto err;
189 if (BN_num_bits(k) <= BN_num_bits(dsa->q)) {
190 if (!BN_add(k, k, dsa->q))
191 goto err;
192 }
193
194 if ((dsa)->meth->bn_mod_exp != NULL) {
195 if (!dsa->meth->bn_mod_exp(dsa, r, dsa->g, k, dsa->p, ctx,
196 dsa->method_mont_p))
197 goto err;
198 } else {
199 if (!BN_mod_exp_mont(r, dsa->g, k, dsa->p, ctx, dsa->method_mont_p))
200 goto err;
201 }
202
203 if (!BN_mod(r, r, dsa->q, ctx))
204 goto err;
205
206 /* Compute part of 's = inv(k) (m + xr) mod q' */
207 if ((kinv = BN_mod_inverse(NULL, k, dsa->q, ctx)) == NULL)
208 goto err;
209
210 BN_clear_free(*kinvp);
211 *kinvp = kinv;
212 kinv = NULL;
213 ret = 1;
214 err:
215 if (!ret)
216 DSAerr(DSA_F_DSA_SIGN_SETUP, ERR_R_BN_LIB);
217 if (ctx != ctx_in)
218 BN_CTX_free(ctx);
219 BN_clear_free(k);
220 return ret;
221}
222
223static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
224 DSA_SIG *sig, DSA *dsa)
225{
226 BN_CTX *ctx;
227 BIGNUM *u1, *u2, *t1;
228 BN_MONT_CTX *mont = NULL;
229 const BIGNUM *r, *s;
230 int ret = -1, i;
231 if (!dsa->p || !dsa->q || !dsa->g) {
232 DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_MISSING_PARAMETERS);
233 return -1;
234 }
235
236 i = BN_num_bits(dsa->q);
237 /* fips 186-3 allows only different sizes for q */
238 if (i != 160 && i != 224 && i != 256) {
239 DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_BAD_Q_VALUE);
240 return -1;
241 }
242
243 if (BN_num_bits(dsa->p) > OPENSSL_DSA_MAX_MODULUS_BITS) {
244 DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_MODULUS_TOO_LARGE);
245 return -1;
246 }
247 u1 = BN_new();
248 u2 = BN_new();
249 t1 = BN_new();
250 ctx = BN_CTX_new();
251 if (u1 == NULL || u2 == NULL || t1 == NULL || ctx == NULL)
252 goto err;
253
254 DSA_SIG_get0(sig, &r, &s);
255
256 if (BN_is_zero(r) || BN_is_negative(r) ||
257 BN_ucmp(r, dsa->q) >= 0) {
258 ret = 0;
259 goto err;
260 }
261 if (BN_is_zero(s) || BN_is_negative(s) ||
262 BN_ucmp(s, dsa->q) >= 0) {
263 ret = 0;
264 goto err;
265 }
266
267 /*
268 * Calculate W = inv(S) mod Q save W in u2
269 */
270 if ((BN_mod_inverse(u2, s, dsa->q, ctx)) == NULL)
271 goto err;
272
273 /* save M in u1 */
274 if (dgst_len > (i >> 3))
275 /*
276 * if the digest length is greater than the size of q use the
277 * BN_num_bits(dsa->q) leftmost bits of the digest, see fips 186-3,
278 * 4.2
279 */
280 dgst_len = (i >> 3);
281 if (BN_bin2bn(dgst, dgst_len, u1) == NULL)
282 goto err;
283
284 /* u1 = M * w mod q */
285 if (!BN_mod_mul(u1, u1, u2, dsa->q, ctx))
286 goto err;
287
288 /* u2 = r * w mod q */
289 if (!BN_mod_mul(u2, r, u2, dsa->q, ctx))
290 goto err;
291
292 if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {
293 mont = BN_MONT_CTX_set_locked(&dsa->method_mont_p,
294 dsa->lock, dsa->p, ctx);
295 if (!mont)
296 goto err;
297 }
298
299 if (dsa->meth->dsa_mod_exp != NULL) {
300 if (!dsa->meth->dsa_mod_exp(dsa, t1, dsa->g, u1, dsa->pub_key, u2,
301 dsa->p, ctx, mont))
302 goto err;
303 } else {
304 if (!BN_mod_exp2_mont(t1, dsa->g, u1, dsa->pub_key, u2, dsa->p, ctx,
305 mont))
306 goto err;
307 }
308
309 /* let u1 = u1 mod q */
310 if (!BN_mod(u1, t1, dsa->q, ctx))
311 goto err;
312
313 /*
314 * V is now in u1. If the signature is correct, it will be equal to R.
315 */
316 ret = (BN_ucmp(u1, r) == 0);
317
318 err:
319 if (ret < 0)
320 DSAerr(DSA_F_DSA_DO_VERIFY, ERR_R_BN_LIB);
321 BN_CTX_free(ctx);
322 BN_free(u1);
323 BN_free(u2);
324 BN_free(t1);
325 return (ret);
326}
327
328static int dsa_init(DSA *dsa)
329{
330 dsa->flags |= DSA_FLAG_CACHE_MONT_P;
331 return (1);
332}
333
334static int dsa_finish(DSA *dsa)
335{
336 BN_MONT_CTX_free(dsa->method_mont_p);
337 return (1);
338}
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