1 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
2 * project 2000. */
3 /* ====================================================================
4 * Copyright (c) 2000-2005 The OpenSSL Project. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 *
18 * 3. All advertising materials mentioning features or use of this
19 * software must display the following acknowledgment:
20 * "This product includes software developed by the OpenSSL Project
21 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
22 *
23 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
24 * endorse or promote products derived from this software without
25 * prior written permission. For written permission, please contact
26 * licensing@OpenSSL.org.
27 *
28 * 5. Products derived from this software may not be called "OpenSSL"
29 * nor may "OpenSSL" appear in their names without prior written
30 * permission of the OpenSSL Project.
31 *
32 * 6. Redistributions of any form whatsoever must retain the following
33 * acknowledgment:
34 * "This product includes software developed by the OpenSSL Project
35 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
38 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
40 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
43 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
44 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
46 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
47 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
48 * OF THE POSSIBILITY OF SUCH DAMAGE.
49 * ====================================================================
50 *
51 * This product includes cryptographic software written by Eric Young
52 * (eay@cryptsoft.com). This product includes software written by Tim
53 * Hudson (tjh@cryptsoft.com). */
54
55 #include <openssl/dsa.h>
56
57 #include <assert.h>
58
59 #include <openssl/bn.h>
60 #include <openssl/bytestring.h>
61 #include <openssl/err.h>
62 #include <openssl/mem.h>
63
64 #include "internal.h"
65 #include "../bytestring/internal.h"
66
67
68 #define OPENSSL_DSA_MAX_MODULUS_BITS 10000
69
70 // This function is in dsa_asn1.c rather than dsa.c because it is reachable from
71 // |EVP_PKEY| parsers. This makes it easier for the static linker to drop most
72 // of the DSA implementation.
dsa_check_parameters(const DSA * dsa)73 int dsa_check_parameters(const DSA *dsa) {
74 if (!dsa->p || !dsa->q || !dsa->g) {
75 OPENSSL_PUT_ERROR(DSA, DSA_R_MISSING_PARAMETERS);
76 return 0;
77 }
78
79 // Reject invalid parameters. In particular, signing will infinite loop if |g|
80 // is zero.
81 if (BN_is_zero(dsa->p) || BN_is_zero(dsa->q) || BN_is_zero(dsa->g)) {
82 OPENSSL_PUT_ERROR(DSA, DSA_R_INVALID_PARAMETERS);
83 return 0;
84 }
85
86 // FIPS 186-4 allows only three different sizes for q.
87 unsigned q_bits = BN_num_bits(dsa->q);
88 if (q_bits != 160 && q_bits != 224 && q_bits != 256) {
89 OPENSSL_PUT_ERROR(DSA, DSA_R_BAD_Q_VALUE);
90 return 0;
91 }
92
93 // Bound |dsa->p| to avoid a DoS vector. Note this limit is much larger than
94 // the one in FIPS 186-4, which only allows L = 1024, 2048, and 3072.
95 if (BN_num_bits(dsa->p) > OPENSSL_DSA_MAX_MODULUS_BITS) {
96 OPENSSL_PUT_ERROR(DSA, DSA_R_MODULUS_TOO_LARGE);
97 return 0;
98 }
99
100 return 1;
101 }
102
parse_integer(CBS * cbs,BIGNUM ** out)103 static int parse_integer(CBS *cbs, BIGNUM **out) {
104 assert(*out == NULL);
105 *out = BN_new();
106 if (*out == NULL) {
107 return 0;
108 }
109 return BN_parse_asn1_unsigned(cbs, *out);
110 }
111
marshal_integer(CBB * cbb,BIGNUM * bn)112 static int marshal_integer(CBB *cbb, BIGNUM *bn) {
113 if (bn == NULL) {
114 // A DSA object may be missing some components.
115 OPENSSL_PUT_ERROR(DSA, ERR_R_PASSED_NULL_PARAMETER);
116 return 0;
117 }
118 return BN_marshal_asn1(cbb, bn);
119 }
120
DSA_SIG_parse(CBS * cbs)121 DSA_SIG *DSA_SIG_parse(CBS *cbs) {
122 DSA_SIG *ret = DSA_SIG_new();
123 if (ret == NULL) {
124 return NULL;
125 }
126 CBS child;
127 if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
128 !parse_integer(&child, &ret->r) ||
129 !parse_integer(&child, &ret->s) ||
130 CBS_len(&child) != 0) {
131 OPENSSL_PUT_ERROR(DSA, DSA_R_DECODE_ERROR);
132 DSA_SIG_free(ret);
133 return NULL;
134 }
135 return ret;
136 }
137
DSA_SIG_marshal(CBB * cbb,const DSA_SIG * sig)138 int DSA_SIG_marshal(CBB *cbb, const DSA_SIG *sig) {
139 CBB child;
140 if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
141 !marshal_integer(&child, sig->r) ||
142 !marshal_integer(&child, sig->s) ||
143 !CBB_flush(cbb)) {
144 OPENSSL_PUT_ERROR(DSA, DSA_R_ENCODE_ERROR);
145 return 0;
146 }
147 return 1;
148 }
149
DSA_parse_public_key(CBS * cbs)150 DSA *DSA_parse_public_key(CBS *cbs) {
151 DSA *ret = DSA_new();
152 if (ret == NULL) {
153 return NULL;
154 }
155 CBS child;
156 if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
157 !parse_integer(&child, &ret->pub_key) ||
158 !parse_integer(&child, &ret->p) ||
159 !parse_integer(&child, &ret->q) ||
160 !parse_integer(&child, &ret->g) ||
161 CBS_len(&child) != 0) {
162 OPENSSL_PUT_ERROR(DSA, DSA_R_DECODE_ERROR);
163 goto err;
164 }
165 if (!dsa_check_parameters(ret)) {
166 goto err;
167 }
168 return ret;
169
170 err:
171 DSA_free(ret);
172 return NULL;
173 }
174
DSA_marshal_public_key(CBB * cbb,const DSA * dsa)175 int DSA_marshal_public_key(CBB *cbb, const DSA *dsa) {
176 CBB child;
177 if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
178 !marshal_integer(&child, dsa->pub_key) ||
179 !marshal_integer(&child, dsa->p) ||
180 !marshal_integer(&child, dsa->q) ||
181 !marshal_integer(&child, dsa->g) ||
182 !CBB_flush(cbb)) {
183 OPENSSL_PUT_ERROR(DSA, DSA_R_ENCODE_ERROR);
184 return 0;
185 }
186 return 1;
187 }
188
DSA_parse_parameters(CBS * cbs)189 DSA *DSA_parse_parameters(CBS *cbs) {
190 DSA *ret = DSA_new();
191 if (ret == NULL) {
192 return NULL;
193 }
194 CBS child;
195 if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
196 !parse_integer(&child, &ret->p) ||
197 !parse_integer(&child, &ret->q) ||
198 !parse_integer(&child, &ret->g) ||
199 CBS_len(&child) != 0) {
200 OPENSSL_PUT_ERROR(DSA, DSA_R_DECODE_ERROR);
201 goto err;
202 }
203 if (!dsa_check_parameters(ret)) {
204 goto err;
205 }
206 return ret;
207
208 err:
209 DSA_free(ret);
210 return NULL;
211 }
212
DSA_marshal_parameters(CBB * cbb,const DSA * dsa)213 int DSA_marshal_parameters(CBB *cbb, const DSA *dsa) {
214 CBB child;
215 if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
216 !marshal_integer(&child, dsa->p) ||
217 !marshal_integer(&child, dsa->q) ||
218 !marshal_integer(&child, dsa->g) ||
219 !CBB_flush(cbb)) {
220 OPENSSL_PUT_ERROR(DSA, DSA_R_ENCODE_ERROR);
221 return 0;
222 }
223 return 1;
224 }
225
DSA_parse_private_key(CBS * cbs)226 DSA *DSA_parse_private_key(CBS *cbs) {
227 DSA *ret = DSA_new();
228 if (ret == NULL) {
229 return NULL;
230 }
231
232 CBS child;
233 uint64_t version;
234 if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
235 !CBS_get_asn1_uint64(&child, &version)) {
236 OPENSSL_PUT_ERROR(DSA, DSA_R_DECODE_ERROR);
237 goto err;
238 }
239
240 if (version != 0) {
241 OPENSSL_PUT_ERROR(DSA, DSA_R_BAD_VERSION);
242 goto err;
243 }
244
245 if (!parse_integer(&child, &ret->p) ||
246 !parse_integer(&child, &ret->q) ||
247 !parse_integer(&child, &ret->g) ||
248 !parse_integer(&child, &ret->pub_key) ||
249 !parse_integer(&child, &ret->priv_key) ||
250 CBS_len(&child) != 0) {
251 OPENSSL_PUT_ERROR(DSA, DSA_R_DECODE_ERROR);
252 goto err;
253 }
254 if (!dsa_check_parameters(ret)) {
255 goto err;
256 }
257 return ret;
258
259 err:
260 DSA_free(ret);
261 return NULL;
262 }
263
DSA_marshal_private_key(CBB * cbb,const DSA * dsa)264 int DSA_marshal_private_key(CBB *cbb, const DSA *dsa) {
265 CBB child;
266 if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
267 !CBB_add_asn1_uint64(&child, 0 /* version */) ||
268 !marshal_integer(&child, dsa->p) ||
269 !marshal_integer(&child, dsa->q) ||
270 !marshal_integer(&child, dsa->g) ||
271 !marshal_integer(&child, dsa->pub_key) ||
272 !marshal_integer(&child, dsa->priv_key) ||
273 !CBB_flush(cbb)) {
274 OPENSSL_PUT_ERROR(DSA, DSA_R_ENCODE_ERROR);
275 return 0;
276 }
277 return 1;
278 }
279
d2i_DSA_SIG(DSA_SIG ** out_sig,const uint8_t ** inp,long len)280 DSA_SIG *d2i_DSA_SIG(DSA_SIG **out_sig, const uint8_t **inp, long len) {
281 if (len < 0) {
282 return NULL;
283 }
284 CBS cbs;
285 CBS_init(&cbs, *inp, (size_t)len);
286 DSA_SIG *ret = DSA_SIG_parse(&cbs);
287 if (ret == NULL) {
288 return NULL;
289 }
290 if (out_sig != NULL) {
291 DSA_SIG_free(*out_sig);
292 *out_sig = ret;
293 }
294 *inp = CBS_data(&cbs);
295 return ret;
296 }
297
i2d_DSA_SIG(const DSA_SIG * in,uint8_t ** outp)298 int i2d_DSA_SIG(const DSA_SIG *in, uint8_t **outp) {
299 CBB cbb;
300 if (!CBB_init(&cbb, 0) ||
301 !DSA_SIG_marshal(&cbb, in)) {
302 CBB_cleanup(&cbb);
303 return -1;
304 }
305 return CBB_finish_i2d(&cbb, outp);
306 }
307
d2i_DSAPublicKey(DSA ** out,const uint8_t ** inp,long len)308 DSA *d2i_DSAPublicKey(DSA **out, const uint8_t **inp, long len) {
309 if (len < 0) {
310 return NULL;
311 }
312 CBS cbs;
313 CBS_init(&cbs, *inp, (size_t)len);
314 DSA *ret = DSA_parse_public_key(&cbs);
315 if (ret == NULL) {
316 return NULL;
317 }
318 if (out != NULL) {
319 DSA_free(*out);
320 *out = ret;
321 }
322 *inp = CBS_data(&cbs);
323 return ret;
324 }
325
i2d_DSAPublicKey(const DSA * in,uint8_t ** outp)326 int i2d_DSAPublicKey(const DSA *in, uint8_t **outp) {
327 CBB cbb;
328 if (!CBB_init(&cbb, 0) ||
329 !DSA_marshal_public_key(&cbb, in)) {
330 CBB_cleanup(&cbb);
331 return -1;
332 }
333 return CBB_finish_i2d(&cbb, outp);
334 }
335
d2i_DSAPrivateKey(DSA ** out,const uint8_t ** inp,long len)336 DSA *d2i_DSAPrivateKey(DSA **out, const uint8_t **inp, long len) {
337 if (len < 0) {
338 return NULL;
339 }
340 CBS cbs;
341 CBS_init(&cbs, *inp, (size_t)len);
342 DSA *ret = DSA_parse_private_key(&cbs);
343 if (ret == NULL) {
344 return NULL;
345 }
346 if (out != NULL) {
347 DSA_free(*out);
348 *out = ret;
349 }
350 *inp = CBS_data(&cbs);
351 return ret;
352 }
353
i2d_DSAPrivateKey(const DSA * in,uint8_t ** outp)354 int i2d_DSAPrivateKey(const DSA *in, uint8_t **outp) {
355 CBB cbb;
356 if (!CBB_init(&cbb, 0) ||
357 !DSA_marshal_private_key(&cbb, in)) {
358 CBB_cleanup(&cbb);
359 return -1;
360 }
361 return CBB_finish_i2d(&cbb, outp);
362 }
363
d2i_DSAparams(DSA ** out,const uint8_t ** inp,long len)364 DSA *d2i_DSAparams(DSA **out, const uint8_t **inp, long len) {
365 if (len < 0) {
366 return NULL;
367 }
368 CBS cbs;
369 CBS_init(&cbs, *inp, (size_t)len);
370 DSA *ret = DSA_parse_parameters(&cbs);
371 if (ret == NULL) {
372 return NULL;
373 }
374 if (out != NULL) {
375 DSA_free(*out);
376 *out = ret;
377 }
378 *inp = CBS_data(&cbs);
379 return ret;
380 }
381
i2d_DSAparams(const DSA * in,uint8_t ** outp)382 int i2d_DSAparams(const DSA *in, uint8_t **outp) {
383 CBB cbb;
384 if (!CBB_init(&cbb, 0) ||
385 !DSA_marshal_parameters(&cbb, in)) {
386 CBB_cleanup(&cbb);
387 return -1;
388 }
389 return CBB_finish_i2d(&cbb, outp);
390 }
391