1 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
2 * project 2006.
3 */
4 /* ====================================================================
5 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 *
19 * 3. All advertising materials mentioning features or use of this
20 * software must display the following acknowledgment:
21 * "This product includes software developed by the OpenSSL Project
22 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
23 *
24 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
25 * endorse or promote products derived from this software without
26 * prior written permission. For written permission, please contact
27 * licensing@OpenSSL.org.
28 *
29 * 5. Products derived from this software may not be called "OpenSSL"
30 * nor may "OpenSSL" appear in their names without prior written
31 * permission of the OpenSSL Project.
32 *
33 * 6. Redistributions of any form whatsoever must retain the following
34 * acknowledgment:
35 * "This product includes software developed by the OpenSSL Project
36 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
37 *
38 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
39 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
41 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
42 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
47 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
48 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
49 * OF THE POSSIBILITY OF SUCH DAMAGE.
50 * ====================================================================
51 *
52 * This product includes cryptographic software written by Eric Young
53 * (eay@cryptsoft.com). This product includes software written by Tim
54 * Hudson (tjh@cryptsoft.com). */
55
56 #include <openssl/x509.h>
57
58 #include <assert.h>
59
60 #include <openssl/asn1.h>
61 #include <openssl/asn1t.h>
62 #include <openssl/bio.h>
63 #include <openssl/evp.h>
64 #include <openssl/err.h>
65 #include <openssl/obj.h>
66
67 #include "internal.h"
68
69
70 ASN1_SEQUENCE(RSA_PSS_PARAMS) = {
71 ASN1_EXP_OPT(RSA_PSS_PARAMS, hashAlgorithm, X509_ALGOR,0),
72 ASN1_EXP_OPT(RSA_PSS_PARAMS, maskGenAlgorithm, X509_ALGOR,1),
73 ASN1_EXP_OPT(RSA_PSS_PARAMS, saltLength, ASN1_INTEGER,2),
74 ASN1_EXP_OPT(RSA_PSS_PARAMS, trailerField, ASN1_INTEGER,3),
75 } ASN1_SEQUENCE_END(RSA_PSS_PARAMS)
76
77 IMPLEMENT_ASN1_FUNCTIONS(RSA_PSS_PARAMS)
78
79
80 /* Given an MGF1 Algorithm ID decode to an Algorithm Identifier */
81 static X509_ALGOR *rsa_mgf1_decode(X509_ALGOR *alg) {
82 if (alg == NULL || alg->parameter == NULL ||
83 OBJ_obj2nid(alg->algorithm) != NID_mgf1 ||
84 alg->parameter->type != V_ASN1_SEQUENCE) {
85 return NULL;
86 }
87
88 const uint8_t *p = alg->parameter->value.sequence->data;
89 int plen = alg->parameter->value.sequence->length;
90 return d2i_X509_ALGOR(NULL, &p, plen);
91 }
92
rsa_pss_decode(const X509_ALGOR * alg,X509_ALGOR ** pmaskHash)93 static RSA_PSS_PARAMS *rsa_pss_decode(const X509_ALGOR *alg,
94 X509_ALGOR **pmaskHash) {
95 *pmaskHash = NULL;
96
97 if (alg->parameter == NULL || alg->parameter->type != V_ASN1_SEQUENCE) {
98 return NULL;
99 }
100
101 const uint8_t *p = alg->parameter->value.sequence->data;
102 int plen = alg->parameter->value.sequence->length;
103 RSA_PSS_PARAMS *pss = d2i_RSA_PSS_PARAMS(NULL, &p, plen);
104 if (pss == NULL) {
105 return NULL;
106 }
107
108 *pmaskHash = rsa_mgf1_decode(pss->maskGenAlgorithm);
109 return pss;
110 }
111
112 /* allocate and set algorithm ID from EVP_MD, default SHA1 */
rsa_md_to_algor(X509_ALGOR ** palg,const EVP_MD * md)113 static int rsa_md_to_algor(X509_ALGOR **palg, const EVP_MD *md) {
114 if (EVP_MD_type(md) == NID_sha1) {
115 return 1;
116 }
117 *palg = X509_ALGOR_new();
118 if (*palg == NULL) {
119 return 0;
120 }
121 X509_ALGOR_set_md(*palg, md);
122 return 1;
123 }
124
125 /* Allocate and set MGF1 algorithm ID from EVP_MD */
rsa_md_to_mgf1(X509_ALGOR ** palg,const EVP_MD * mgf1md)126 static int rsa_md_to_mgf1(X509_ALGOR **palg, const EVP_MD *mgf1md) {
127 X509_ALGOR *algtmp = NULL;
128 ASN1_STRING *stmp = NULL;
129 *palg = NULL;
130
131 if (EVP_MD_type(mgf1md) == NID_sha1) {
132 return 1;
133 }
134 /* need to embed algorithm ID inside another */
135 if (!rsa_md_to_algor(&algtmp, mgf1md) ||
136 !ASN1_item_pack(algtmp, ASN1_ITEM_rptr(X509_ALGOR), &stmp)) {
137 goto err;
138 }
139 *palg = X509_ALGOR_new();
140 if (!*palg) {
141 goto err;
142 }
143 X509_ALGOR_set0(*palg, OBJ_nid2obj(NID_mgf1), V_ASN1_SEQUENCE, stmp);
144 stmp = NULL;
145
146 err:
147 ASN1_STRING_free(stmp);
148 X509_ALGOR_free(algtmp);
149 if (*palg) {
150 return 1;
151 }
152
153 return 0;
154 }
155
156 /* convert algorithm ID to EVP_MD, default SHA1 */
rsa_algor_to_md(X509_ALGOR * alg)157 static const EVP_MD *rsa_algor_to_md(X509_ALGOR *alg) {
158 const EVP_MD *md;
159 if (!alg) {
160 return EVP_sha1();
161 }
162 md = EVP_get_digestbyobj(alg->algorithm);
163 if (md == NULL) {
164 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PSS_PARAMETERS);
165 }
166 return md;
167 }
168
169 /* convert MGF1 algorithm ID to EVP_MD, default SHA1 */
rsa_mgf1_to_md(const X509_ALGOR * alg,X509_ALGOR * maskHash)170 static const EVP_MD *rsa_mgf1_to_md(const X509_ALGOR *alg,
171 X509_ALGOR *maskHash) {
172 const EVP_MD *md;
173 if (!alg) {
174 return EVP_sha1();
175 }
176 /* Check mask and lookup mask hash algorithm */
177 if (OBJ_obj2nid(alg->algorithm) != NID_mgf1 ||
178 maskHash == NULL) {
179 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PSS_PARAMETERS);
180 return NULL;
181 }
182 md = EVP_get_digestbyobj(maskHash->algorithm);
183 if (md == NULL) {
184 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PSS_PARAMETERS);
185 return NULL;
186 }
187 return md;
188 }
189
x509_rsa_ctx_to_pss(EVP_MD_CTX * ctx,X509_ALGOR * algor)190 int x509_rsa_ctx_to_pss(EVP_MD_CTX *ctx, X509_ALGOR *algor) {
191 const EVP_MD *sigmd, *mgf1md;
192 int saltlen;
193 if (!EVP_PKEY_CTX_get_signature_md(ctx->pctx, &sigmd) ||
194 !EVP_PKEY_CTX_get_rsa_mgf1_md(ctx->pctx, &mgf1md) ||
195 !EVP_PKEY_CTX_get_rsa_pss_saltlen(ctx->pctx, &saltlen)) {
196 return 0;
197 }
198
199 EVP_PKEY *pk = EVP_PKEY_CTX_get0_pkey(ctx->pctx);
200 if (saltlen == -1) {
201 saltlen = EVP_MD_size(sigmd);
202 } else if (saltlen == -2) {
203 // TODO(davidben): Forbid this mode. The world has largely standardized on
204 // salt length matching hash length.
205 saltlen = EVP_PKEY_size(pk) - EVP_MD_size(sigmd) - 2;
206 if (((EVP_PKEY_bits(pk) - 1) & 0x7) == 0) {
207 saltlen--;
208 }
209 } else if (saltlen != (int)EVP_MD_size(sigmd)) {
210 // We only allow salt length matching hash length and, for now, the -2 case.
211 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PSS_PARAMETERS);
212 return 0;
213 }
214
215 int ret = 0;
216 ASN1_STRING *os = NULL;
217 RSA_PSS_PARAMS *pss = RSA_PSS_PARAMS_new();
218 if (!pss) {
219 goto err;
220 }
221
222 if (saltlen != 20) {
223 pss->saltLength = ASN1_INTEGER_new();
224 if (!pss->saltLength ||
225 !ASN1_INTEGER_set(pss->saltLength, saltlen)) {
226 goto err;
227 }
228 }
229
230 if (!rsa_md_to_algor(&pss->hashAlgorithm, sigmd) ||
231 !rsa_md_to_mgf1(&pss->maskGenAlgorithm, mgf1md)) {
232 goto err;
233 }
234
235 /* Finally create string with pss parameter encoding. */
236 if (!ASN1_item_pack(pss, ASN1_ITEM_rptr(RSA_PSS_PARAMS), &os)) {
237 goto err;
238 }
239
240 X509_ALGOR_set0(algor, OBJ_nid2obj(NID_rsassaPss), V_ASN1_SEQUENCE, os);
241 os = NULL;
242 ret = 1;
243
244 err:
245 RSA_PSS_PARAMS_free(pss);
246 ASN1_STRING_free(os);
247 return ret;
248 }
249
x509_rsa_pss_to_ctx(EVP_MD_CTX * ctx,const X509_ALGOR * sigalg,EVP_PKEY * pkey)250 int x509_rsa_pss_to_ctx(EVP_MD_CTX *ctx, const X509_ALGOR *sigalg,
251 EVP_PKEY *pkey) {
252 assert(OBJ_obj2nid(sigalg->algorithm) == NID_rsassaPss);
253
254 /* Decode PSS parameters */
255 int ret = 0;
256 X509_ALGOR *maskHash;
257 RSA_PSS_PARAMS *pss = rsa_pss_decode(sigalg, &maskHash);
258 if (pss == NULL) {
259 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PSS_PARAMETERS);
260 goto err;
261 }
262
263 const EVP_MD *mgf1md = rsa_mgf1_to_md(pss->maskGenAlgorithm, maskHash);
264 const EVP_MD *md = rsa_algor_to_md(pss->hashAlgorithm);
265 if (mgf1md == NULL || md == NULL) {
266 goto err;
267 }
268
269 int saltlen = 20;
270 if (pss->saltLength != NULL) {
271 saltlen = ASN1_INTEGER_get(pss->saltLength);
272
273 /* Could perform more salt length sanity checks but the main
274 * RSA routines will trap other invalid values anyway. */
275 if (saltlen < 0) {
276 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PSS_PARAMETERS);
277 goto err;
278 }
279 }
280
281 /* low-level routines support only trailer field 0xbc (value 1)
282 * and PKCS#1 says we should reject any other value anyway. */
283 if (pss->trailerField != NULL && ASN1_INTEGER_get(pss->trailerField) != 1) {
284 OPENSSL_PUT_ERROR(X509, X509_R_INVALID_PSS_PARAMETERS);
285 goto err;
286 }
287
288 EVP_PKEY_CTX *pctx;
289 if (!EVP_DigestVerifyInit(ctx, &pctx, md, NULL, pkey) ||
290 !EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) ||
291 !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, saltlen) ||
292 !EVP_PKEY_CTX_set_rsa_mgf1_md(pctx, mgf1md)) {
293 goto err;
294 }
295
296 ret = 1;
297
298 err:
299 RSA_PSS_PARAMS_free(pss);
300 X509_ALGOR_free(maskHash);
301 return ret;
302 }
303
x509_print_rsa_pss_params(BIO * bp,const X509_ALGOR * sigalg,int indent,ASN1_PCTX * pctx)304 int x509_print_rsa_pss_params(BIO *bp, const X509_ALGOR *sigalg, int indent,
305 ASN1_PCTX *pctx) {
306 assert(OBJ_obj2nid(sigalg->algorithm) == NID_rsassaPss);
307
308 int rv = 0;
309 X509_ALGOR *maskHash;
310 RSA_PSS_PARAMS *pss = rsa_pss_decode(sigalg, &maskHash);
311 if (!pss) {
312 if (BIO_puts(bp, " (INVALID PSS PARAMETERS)\n") <= 0) {
313 goto err;
314 }
315 rv = 1;
316 goto err;
317 }
318
319 if (BIO_puts(bp, "\n") <= 0 ||
320 !BIO_indent(bp, indent, 128) ||
321 BIO_puts(bp, "Hash Algorithm: ") <= 0) {
322 goto err;
323 }
324
325 if (pss->hashAlgorithm) {
326 if (i2a_ASN1_OBJECT(bp, pss->hashAlgorithm->algorithm) <= 0) {
327 goto err;
328 }
329 } else if (BIO_puts(bp, "sha1 (default)") <= 0) {
330 goto err;
331 }
332
333 if (BIO_puts(bp, "\n") <= 0 ||
334 !BIO_indent(bp, indent, 128) ||
335 BIO_puts(bp, "Mask Algorithm: ") <= 0) {
336 goto err;
337 }
338
339 if (pss->maskGenAlgorithm) {
340 if (i2a_ASN1_OBJECT(bp, pss->maskGenAlgorithm->algorithm) <= 0 ||
341 BIO_puts(bp, " with ") <= 0) {
342 goto err;
343 }
344
345 if (maskHash) {
346 if (i2a_ASN1_OBJECT(bp, maskHash->algorithm) <= 0) {
347 goto err;
348 }
349 } else if (BIO_puts(bp, "INVALID") <= 0) {
350 goto err;
351 }
352 } else if (BIO_puts(bp, "mgf1 with sha1 (default)") <= 0) {
353 goto err;
354 }
355 BIO_puts(bp, "\n");
356
357 if (!BIO_indent(bp, indent, 128) ||
358 BIO_puts(bp, "Salt Length: 0x") <= 0) {
359 goto err;
360 }
361
362 if (pss->saltLength) {
363 if (i2a_ASN1_INTEGER(bp, pss->saltLength) <= 0) {
364 goto err;
365 }
366 } else if (BIO_puts(bp, "14 (default)") <= 0) {
367 goto err;
368 }
369 BIO_puts(bp, "\n");
370
371 if (!BIO_indent(bp, indent, 128) ||
372 BIO_puts(bp, "Trailer Field: 0x") <= 0) {
373 goto err;
374 }
375
376 if (pss->trailerField) {
377 if (i2a_ASN1_INTEGER(bp, pss->trailerField) <= 0) {
378 goto err;
379 }
380 } else if (BIO_puts(bp, "BC (default)") <= 0) {
381 goto err;
382 }
383 BIO_puts(bp, "\n");
384
385 rv = 1;
386
387 err:
388 RSA_PSS_PARAMS_free(pss);
389 X509_ALGOR_free(maskHash);
390 return rv;
391 }
392