Bug Summary

File:src/lib/libcrypto/ts/ts_rsp_verify.c
Warning:line 205, column 10
Although the value stored to 'i' is used in the enclosing expression, the value is never actually read from 'i'

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name ts_rsp_verify.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/lib/libcrypto/obj -resource-dir /usr/local/lib/clang/13.0.0 -D LIBRESSL_INTERNAL -D LIBRESSL_CRYPTO_INTERNAL -D DSO_DLFCN -D HAVE_DLFCN_H -D HAVE_FUNOPEN -D OPENSSL_NO_HW_PADLOCK -I /usr/src/lib/libcrypto -I /usr/src/lib/libcrypto/asn1 -I /usr/src/lib/libcrypto/bio -I /usr/src/lib/libcrypto/bn -I /usr/src/lib/libcrypto/bytestring -I /usr/src/lib/libcrypto/dh -I /usr/src/lib/libcrypto/dsa -I /usr/src/lib/libcrypto/ec -I /usr/src/lib/libcrypto/ecdh -I /usr/src/lib/libcrypto/ecdsa -I /usr/src/lib/libcrypto/evp -I /usr/src/lib/libcrypto/hmac -I /usr/src/lib/libcrypto/modes -I /usr/src/lib/libcrypto/ocsp -I /usr/src/lib/libcrypto/rsa -I /usr/src/lib/libcrypto/x509 -I /usr/src/lib/libcrypto/obj -D AES_ASM -D BSAES_ASM -D VPAES_ASM -D OPENSSL_IA32_SSE2 -D RSA_ASM -D OPENSSL_BN_ASM_MONT -D OPENSSL_BN_ASM_MONT5 -D OPENSSL_BN_ASM_GF2m -D MD5_ASM -D GHASH_ASM -D RC4_MD5_ASM -D SHA1_ASM -D SHA256_ASM -D SHA512_ASM -D WHIRLPOOL_ASM -D OPENSSL_CPUID_OBJ -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/lib/libcrypto/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/lib/libcrypto/ts/ts_rsp_verify.c
1/* $OpenBSD: ts_rsp_verify.c,v 1.24 2021/12/12 21:30:14 tb Exp $ */
2/* Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL
3 * project 2002.
4 */
5/* ====================================================================
6 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 * acknowledgment:
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59#include <stdio.h>
60#include <string.h>
61
62#include <openssl/err.h>
63#include <openssl/objects.h>
64#include <openssl/pkcs7.h>
65#include <openssl/ts.h>
66
67#include "evp_locl.h"
68#include "x509_lcl.h"
69
70/* Private function declarations. */
71
72static int TS_verify_cert(X509_STORE *store, STACK_OF(X509)struct stack_st_X509 *untrusted,
73 X509 *signer, STACK_OF(X509)struct stack_st_X509 **chain);
74static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509)struct stack_st_X509 *chain);
75static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si);
76static int TS_find_cert(STACK_OF(ESS_CERT_ID)struct stack_st_ESS_CERT_ID *cert_ids, X509 *cert);
77static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo);
78static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx,
79 PKCS7 *token, TS_TST_INFO *tst_info);
80static int TS_check_status_info(TS_RESP *response);
81static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING)struct stack_st_ASN1_UTF8STRING *text);
82static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info);
83static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info,
84 X509_ALGOR **md_alg,
85 unsigned char **imprint, unsigned *imprint_len);
86static int TS_check_imprints(X509_ALGOR *algor_a,
87 unsigned char *imprint_a, unsigned len_a,
88 TS_TST_INFO *tst_info);
89static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info);
90static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer);
91static int TS_find_name(STACK_OF(GENERAL_NAME)struct stack_st_GENERAL_NAME *gen_names, GENERAL_NAME *name);
92
93/*
94 * Local mapping between response codes and descriptions.
95 * Don't forget to change TS_STATUS_BUF_SIZE when modifying
96 * the elements of this array.
97 */
98static const char *TS_status_text[] = {
99 "granted",
100 "grantedWithMods",
101 "rejection",
102 "waiting",
103 "revocationWarning",
104 "revocationNotification"
105};
106
107#define TS_STATUS_TEXT_SIZE(sizeof(TS_status_text)/sizeof(*TS_status_text)) (sizeof(TS_status_text)/sizeof(*TS_status_text))
108
109/*
110 * This must be greater or equal to the sum of the strings in TS_status_text
111 * plus the number of its elements.
112 */
113#define TS_STATUS_BUF_SIZE256 256
114
115static struct {
116 int code;
117 const char *text;
118} TS_failure_info[] = {
119 { TS_INFO_BAD_ALG0, "badAlg" },
120 { TS_INFO_BAD_REQUEST2, "badRequest" },
121 { TS_INFO_BAD_DATA_FORMAT5, "badDataFormat" },
122 { TS_INFO_TIME_NOT_AVAILABLE14, "timeNotAvailable" },
123 { TS_INFO_UNACCEPTED_POLICY15, "unacceptedPolicy" },
124 { TS_INFO_UNACCEPTED_EXTENSION16, "unacceptedExtension" },
125 { TS_INFO_ADD_INFO_NOT_AVAILABLE17, "addInfoNotAvailable" },
126 { TS_INFO_SYSTEM_FAILURE25, "systemFailure" }
127};
128
129#define TS_FAILURE_INFO_SIZE(sizeof(TS_failure_info) / sizeof(*TS_failure_info)) (sizeof(TS_failure_info) / \
130 sizeof(*TS_failure_info))
131
132/* Functions for verifying a signed TS_TST_INFO structure. */
133
134/*
135 * This function carries out the following tasks:
136 * - Checks if there is one and only one signer.
137 * - Search for the signing certificate in 'certs' and in the response.
138 * - Check the extended key usage and key usage fields of the signer
139 * certificate (done by the path validation).
140 * - Build and validate the certificate path.
141 * - Check if the certificate path meets the requirements of the
142 * SigningCertificate ESS signed attribute.
143 * - Verify the signature value.
144 * - Returns the signer certificate in 'signer', if 'signer' is not NULL.
145 */
146int
147TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509)struct stack_st_X509 *certs,
148 X509_STORE *store, X509 **signer_out)
149{
150 STACK_OF(PKCS7_SIGNER_INFO)struct stack_st_PKCS7_SIGNER_INFO *sinfos = NULL((void*)0);
151 PKCS7_SIGNER_INFO *si;
152 STACK_OF(X509)struct stack_st_X509 *signers = NULL((void*)0);
153 X509 *signer;
154 STACK_OF(X509)struct stack_st_X509 *chain = NULL((void*)0);
155 char buf[4096];
156 int i, j = 0, ret = 0;
157 BIO *p7bio = NULL((void*)0);
158
159 /* Some sanity checks first. */
160 if (!token) {
161 TSerror(TS_R_INVALID_NULL_POINTER)ERR_put_error(47,(0xfff),(102),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,161);
162 goto err;
163 }
164
165 /* Check for the correct content type */
166 if (!PKCS7_type_is_signed(token)(OBJ_obj2nid((token)->type) == 22)) {
167 TSerror(TS_R_WRONG_CONTENT_TYPE)ERR_put_error(47,(0xfff),(114),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,167);
168 goto err;
169 }
170
171 /* Check if there is one and only one signer. */
172 sinfos = PKCS7_get_signer_info(token);
173 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos)sk_num(((_STACK*) (1 ? (sinfos) : (struct stack_st_PKCS7_SIGNER_INFO
*)0))) != 1) {
174 TSerror(TS_R_THERE_MUST_BE_ONE_SIGNER)ERR_put_error(47,(0xfff),(110),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,174);
175 goto err;
176 }
177 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0)((PKCS7_SIGNER_INFO *)sk_value(((_STACK*) (1 ? (sinfos) : (struct
stack_st_PKCS7_SIGNER_INFO*)0)), (0)));
178
179 /* Check for no content: no data to verify signature. */
180 if (PKCS7_get_detached(token)PKCS7_ctrl(token,2,0,((void*)0))) {
181 TSerror(TS_R_NO_CONTENT)ERR_put_error(47,(0xfff),(106),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,181);
182 goto err;
183 }
184
185 /* Get hold of the signer certificate, search only internal
186 certificates if it was requested. */
187 signers = PKCS7_get0_signers(token, certs, 0);
188 if (!signers || sk_X509_num(signers)sk_num(((_STACK*) (1 ? (signers) : (struct stack_st_X509*)0))
) != 1)
189 goto err;
190 signer = sk_X509_value(signers, 0)((X509 *)sk_value(((_STACK*) (1 ? (signers) : (struct stack_st_X509
*)0)), (0)));
191
192 /* Now verify the certificate. */
193 if (!TS_verify_cert(store, certs, signer, &chain))
194 goto err;
195
196 /* Check if the signer certificate is consistent with the
197 ESS extension. */
198 if (!TS_check_signing_certs(si, chain))
199 goto err;
200
201 /* Creating the message digest. */
202 p7bio = PKCS7_dataInit(token, NULL((void*)0));
203
204 /* We now have to 'read' from p7bio to calculate digests etc. */
205 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0)
Although the value stored to 'i' is used in the enclosing expression, the value is never actually read from 'i'
206 ;
207
208 /* Verifying the signature. */
209 j = PKCS7_signatureVerify(p7bio, token, si, signer);
210 if (j <= 0) {
211 TSerror(TS_R_SIGNATURE_FAILURE)ERR_put_error(47,(0xfff),(109),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,211);
212 goto err;
213 }
214
215 /* Return the signer certificate if needed. */
216 if (signer_out) {
217 *signer_out = signer;
218 CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509)CRYPTO_add_lock(&signer->references,1,3,((void*)0),0);
219 }
220
221 ret = 1;
222
223err:
224 BIO_free_all(p7bio);
225 sk_X509_pop_free(chain, X509_free)sk_pop_free(((_STACK*) (1 ? (chain) : (struct stack_st_X509*)
0)), ((void (*)(void *)) ((1 ? (X509_free) : (void (*)(X509 *
))0))));
226 sk_X509_free(signers)sk_free(((_STACK*) (1 ? (signers) : (struct stack_st_X509*)0)
));
227
228 return ret;
229}
230
231/*
232 * The certificate chain is returned in chain. Caller is responsible for
233 * freeing the vector.
234 */
235static int
236TS_verify_cert(X509_STORE *store, STACK_OF(X509)struct stack_st_X509 *untrusted, X509 *signer,
237 STACK_OF(X509)struct stack_st_X509 **chain)
238{
239 X509_STORE_CTX cert_ctx;
240 int i;
241 int ret = 0;
242
243 /* chain is an out argument. */
244 *chain = NULL((void*)0);
245 if (X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted) == 0) {
246 TSerror(ERR_R_X509_LIB)ERR_put_error(47,(0xfff),(11),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,246);
247 goto err;
248 }
249 if (X509_STORE_CTX_set_purpose(&cert_ctx,
250 X509_PURPOSE_TIMESTAMP_SIGN9) == 0)
251 goto err;
252 i = X509_verify_cert(&cert_ctx);
253 if (i <= 0) {
254 int j = X509_STORE_CTX_get_error(&cert_ctx);
255
256 TSerror(TS_R_CERTIFICATE_VERIFY_ERROR)ERR_put_error(47,(0xfff),(100),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,256);
257 ERR_asprintf_error_data("Verify error:%s",
258 X509_verify_cert_error_string(j));
259 goto err;
260 } else {
261 /* Get a copy of the certificate chain. */
262 *chain = X509_STORE_CTX_get1_chain(&cert_ctx);
263 ret = 1;
264 }
265
266err:
267 X509_STORE_CTX_cleanup(&cert_ctx);
268
269 return ret;
270}
271
272static int
273TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509)struct stack_st_X509 *chain)
274{
275 ESS_SIGNING_CERT *ss = ESS_get_signing_cert(si);
276 STACK_OF(ESS_CERT_ID)struct stack_st_ESS_CERT_ID *cert_ids = NULL((void*)0);
277 X509 *cert;
278 int i = 0;
279 int ret = 0;
280
281 if (!ss)
282 goto err;
283 cert_ids = ss->cert_ids;
284 /* The signer certificate must be the first in cert_ids. */
285 cert = sk_X509_value(chain, 0)((X509 *)sk_value(((_STACK*) (1 ? (chain) : (struct stack_st_X509
*)0)), (0)));
286 if (TS_find_cert(cert_ids, cert) != 0)
287 goto err;
288
289 /* Check the other certificates of the chain if there are more
290 than one certificate ids in cert_ids. */
291 if (sk_ESS_CERT_ID_num(cert_ids)sk_num(((_STACK*) (1 ? (cert_ids) : (struct stack_st_ESS_CERT_ID
*)0))) > 1) {
292 /* All the certificates of the chain must be in cert_ids. */
293 for (i = 1; i < sk_X509_num(chain)sk_num(((_STACK*) (1 ? (chain) : (struct stack_st_X509*)0))); ++i) {
294 cert = sk_X509_value(chain, i)((X509 *)sk_value(((_STACK*) (1 ? (chain) : (struct stack_st_X509
*)0)), (i)));
295 if (TS_find_cert(cert_ids, cert) < 0)
296 goto err;
297 }
298 }
299 ret = 1;
300
301err:
302 if (!ret)
303 TSerror(TS_R_ESS_SIGNING_CERTIFICATE_ERROR)ERR_put_error(47,(0xfff),(101),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,303);
304 ESS_SIGNING_CERT_free(ss);
305 return ret;
306}
307
308static ESS_SIGNING_CERT *
309ESS_get_signing_cert(PKCS7_SIGNER_INFO *si)
310{
311 ASN1_TYPE *attr;
312 const unsigned char *p;
313
314 attr = PKCS7_get_signed_attribute(si,
315 NID_id_smime_aa_signingCertificate223);
316 if (!attr)
317 return NULL((void*)0);
318 if (attr->type != V_ASN1_SEQUENCE16)
319 return NULL((void*)0);
320 p = attr->value.sequence->data;
321 return d2i_ESS_SIGNING_CERT(NULL((void*)0), &p, attr->value.sequence->length);
322}
323
324/* Returns < 0 if certificate is not found, certificate index otherwise. */
325static int
326TS_find_cert(STACK_OF(ESS_CERT_ID)struct stack_st_ESS_CERT_ID *cert_ids, X509 *cert)
327{
328 int i;
329 unsigned char cert_hash[TS_HASH_LEN20];
330
331 if (!cert_ids || !cert)
332 return -1;
333
334 if (!X509_digest(cert, TS_HASH_EVPEVP_sha1(), cert_hash, NULL((void*)0)))
335 return -1;
336
337 /* Recompute SHA1 hash of certificate if necessary (side effect). */
338 X509_check_purpose(cert, -1, 0);
339
340 /* Look for cert in the cert_ids vector. */
341 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids)sk_num(((_STACK*) (1 ? (cert_ids) : (struct stack_st_ESS_CERT_ID
*)0))); ++i) {
342 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i)((ESS_CERT_ID *)sk_value(((_STACK*) (1 ? (cert_ids) : (struct
stack_st_ESS_CERT_ID*)0)), (i)));
343
344 /* Check the SHA-1 hash first. */
345 if (cid->hash->length == TS_HASH_LEN20 && !memcmp(cid->hash->data,
346 cert_hash, TS_HASH_LEN20)) {
347 /* Check the issuer/serial as well if specified. */
348 ESS_ISSUER_SERIAL *is = cid->issuer_serial;
349 if (!is || !TS_issuer_serial_cmp(is, cert->cert_info))
350 return i;
351 }
352 }
353
354 return -1;
355}
356
357static int
358TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo)
359{
360 GENERAL_NAME *issuer;
361
362 if (!is || !cinfo || sk_GENERAL_NAME_num(is->issuer)sk_num(((_STACK*) (1 ? (is->issuer) : (struct stack_st_GENERAL_NAME
*)0))) != 1)
363 return -1;
364
365 /* Check the issuer first. It must be a directory name. */
366 issuer = sk_GENERAL_NAME_value(is->issuer, 0)((GENERAL_NAME *)sk_value(((_STACK*) (1 ? (is->issuer) : (
struct stack_st_GENERAL_NAME*)0)), (0)));
367 if (issuer->type != GEN_DIRNAME4 ||
368 X509_NAME_cmp(issuer->d.dirn, cinfo->issuer))
369 return -1;
370
371 /* Check the serial number, too. */
372 if (ASN1_INTEGER_cmp(is->serial, cinfo->serialNumber))
373 return -1;
374
375 return 0;
376}
377
378/*
379 * Verifies whether 'response' contains a valid response with regards
380 * to the settings of the context:
381 * - Gives an error message if the TS_TST_INFO is not present.
382 * - Calls _TS_RESP_verify_token to verify the token content.
383 */
384int
385TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response)
386{
387 PKCS7 *token = TS_RESP_get_token(response);
388 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response);
389 int ret = 0;
390
391 /* Check if we have a successful TS_TST_INFO object in place. */
392 if (!TS_check_status_info(response))
393 goto err;
394
395 /* Check the contents of the time stamp token. */
396 if (!int_TS_RESP_verify_token(ctx, token, tst_info))
397 goto err;
398
399 ret = 1;
400
401err:
402 return ret;
403}
404
405/*
406 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and
407 * calls the internal int_TS_RESP_verify_token function for verifying it.
408 */
409int
410TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token)
411{
412 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token);
413 int ret = 0;
414
415 if (tst_info) {
416 ret = int_TS_RESP_verify_token(ctx, token, tst_info);
417 TS_TST_INFO_free(tst_info);
418 }
419 return ret;
420}
421
422/*
423 * Verifies whether the 'token' contains a valid time stamp token
424 * with regards to the settings of the context. Only those checks are
425 * carried out that are specified in the context:
426 * - Verifies the signature of the TS_TST_INFO.
427 * - Checks the version number of the response.
428 * - Check if the requested and returned policies math.
429 * - Check if the message imprints are the same.
430 * - Check if the nonces are the same.
431 * - Check if the TSA name matches the signer.
432 * - Check if the TSA name is the expected TSA.
433 */
434static int
435int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token,
436 TS_TST_INFO *tst_info)
437{
438 X509 *signer = NULL((void*)0);
439 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info);
440 X509_ALGOR *md_alg = NULL((void*)0);
441 unsigned char *imprint = NULL((void*)0);
442 unsigned imprint_len = 0;
443 int ret = 0;
444
445 /* Verify the signature. */
446 if ((ctx->flags & TS_VFY_SIGNATURE(1u << 0)) &&
447 !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer))
448 goto err;
449
450 /* Check version number of response. */
451 if ((ctx->flags & TS_VFY_VERSION(1u << 1)) &&
452 TS_TST_INFO_get_version(tst_info) != 1) {
453 TSerror(TS_R_UNSUPPORTED_VERSION)ERR_put_error(47,(0xfff),(113),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,453);
454 goto err;
455 }
456
457 /* Check policies. */
458 if ((ctx->flags & TS_VFY_POLICY(1u << 2)) &&
459 !TS_check_policy(ctx->policy, tst_info))
460 goto err;
461
462 /* Check message imprints. */
463 if ((ctx->flags & TS_VFY_IMPRINT(1u << 3)) &&
464 !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len,
465 tst_info))
466 goto err;
467
468 /* Compute and check message imprints. */
469 if ((ctx->flags & TS_VFY_DATA(1u << 4)) &&
470 (!TS_compute_imprint(ctx->data, tst_info,
471 &md_alg, &imprint, &imprint_len) ||
472 !TS_check_imprints(md_alg, imprint, imprint_len, tst_info)))
473 goto err;
474
475 /* Check nonces. */
476 if ((ctx->flags & TS_VFY_NONCE(1u << 5)) &&
477 !TS_check_nonces(ctx->nonce, tst_info))
478 goto err;
479
480 /* Check whether TSA name and signer certificate match. */
481 if ((ctx->flags & TS_VFY_SIGNER(1u << 6)) &&
482 tsa_name && !TS_check_signer_name(tsa_name, signer)) {
483 TSerror(TS_R_TSA_NAME_MISMATCH)ERR_put_error(47,(0xfff),(111),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,483);
484 goto err;
485 }
486
487 /* Check whether the TSA is the expected one. */
488 if ((ctx->flags & TS_VFY_TSA_NAME(1u << 7)) &&
489 !TS_check_signer_name(ctx->tsa_name, signer)) {
490 TSerror(TS_R_TSA_UNTRUSTED)ERR_put_error(47,(0xfff),(112),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,490);
491 goto err;
492 }
493
494 ret = 1;
495
496err:
497 X509_free(signer);
498 X509_ALGOR_free(md_alg);
499 free(imprint);
500 return ret;
501}
502
503static int
504TS_check_status_info(TS_RESP *response)
505{
506 TS_STATUS_INFO *info = TS_RESP_get_status_info(response);
507 long status = ASN1_INTEGER_get(info->status);
508 const char *status_text = NULL((void*)0);
509 char *embedded_status_text = NULL((void*)0);
510 char failure_text[TS_STATUS_BUF_SIZE256] = "";
511
512 /* Check if everything went fine. */
513 if (status == 0 || status == 1)
514 return 1;
515
516 /* There was an error, get the description in status_text. */
517 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE(sizeof(TS_status_text)/sizeof(*TS_status_text)))
518 status_text = TS_status_text[status];
519 else
520 status_text = "unknown code";
521
522 /* Set the embedded_status_text to the returned description. */
523 if (sk_ASN1_UTF8STRING_num(info->text)sk_num(((_STACK*) (1 ? (info->text) : (struct stack_st_ASN1_UTF8STRING
*)0))) > 0 &&
524 !(embedded_status_text = TS_get_status_text(info->text)))
525 return 0;
526
527 /* Filling in failure_text with the failure information. */
528 if (info->failure_info) {
529 int i;
530 int first = 1;
531 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE(sizeof(TS_failure_info) / sizeof(*TS_failure_info)); ++i) {
532 if (ASN1_BIT_STRING_get_bit(info->failure_info,
533 TS_failure_info[i].code)) {
534 if (!first)
535 strlcat(failure_text, ",",
536 TS_STATUS_BUF_SIZE256);
537 else
538 first = 0;
539 strlcat(failure_text, TS_failure_info[i].text,
540 TS_STATUS_BUF_SIZE256);
541 }
542 }
543 }
544 if (failure_text[0] == '\0')
545 strlcpy(failure_text, "unspecified", TS_STATUS_BUF_SIZE256);
546
547 /* Making up the error string. */
548 TSerror(TS_R_NO_TIME_STAMP_TOKEN)ERR_put_error(47,(0xfff),(107),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,548);
549 ERR_asprintf_error_data
550 ("status code: %s, status text: %s, failure codes: %s",
551 status_text,
552 embedded_status_text ? embedded_status_text : "unspecified",
553 failure_text);
554 free(embedded_status_text);
555
556 return 0;
557}
558
559static char *
560TS_get_status_text(STACK_OF(ASN1_UTF8STRING)struct stack_st_ASN1_UTF8STRING *text)
561{
562 int i;
563 unsigned int length = 0;
564 char *result = NULL((void*)0);
565
566 /* Determine length first. */
567 for (i = 0; i < sk_ASN1_UTF8STRING_num(text)sk_num(((_STACK*) (1 ? (text) : (struct stack_st_ASN1_UTF8STRING
*)0))); ++i) {
568 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i)((ASN1_UTF8STRING *)sk_value(((_STACK*) (1 ? (text) : (struct
stack_st_ASN1_UTF8STRING*)0)), (i)));
569 length += ASN1_STRING_length(current);
570 length += 1; /* separator character */
571 }
572 /* Allocate memory (closing '\0' included). */
573 if (!(result = malloc(length))) {
574 TSerror(ERR_R_MALLOC_FAILURE)ERR_put_error(47,(0xfff),((1|64)),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,574);
575 return NULL((void*)0);
576 }
577 /* Concatenate the descriptions. */
578 result[0] = '\0';
579 for (i = 0; i < sk_ASN1_UTF8STRING_num(text)sk_num(((_STACK*) (1 ? (text) : (struct stack_st_ASN1_UTF8STRING
*)0))); ++i) {
580 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i)((ASN1_UTF8STRING *)sk_value(((_STACK*) (1 ? (text) : (struct
stack_st_ASN1_UTF8STRING*)0)), (i)));
581 if (i > 0)
582 strlcat(result, "/", length);
583 strlcat(result, (const char *)ASN1_STRING_data(current), length);
584 }
585 return result;
586}
587
588static int
589TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info)
590{
591 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info);
592
593 if (OBJ_cmp(req_oid, resp_oid) != 0) {
594 TSerror(TS_R_POLICY_MISMATCH)ERR_put_error(47,(0xfff),(108),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,594);
595 return 0;
596 }
597
598 return 1;
599}
600
601static int
602TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, X509_ALGOR **out_md_alg,
603 unsigned char **out_imprint, unsigned int *out_imprint_len)
604{
605 TS_MSG_IMPRINT *msg_imprint;
606 X509_ALGOR *md_alg_resp;
607 X509_ALGOR *md_alg = NULL((void*)0);
608 unsigned char *imprint = NULL((void*)0);
609 unsigned int imprint_len = 0;
610 const EVP_MD *md;
611 EVP_MD_CTX md_ctx;
612 unsigned char buffer[4096];
613 int length;
614
615 *out_md_alg = NULL((void*)0);
616 *out_imprint = NULL((void*)0);
617 *out_imprint_len = 0;
618
619 /* Retrieve the MD algorithm of the response. */
620 msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info);
621 md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint);
622 if ((md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL((void*)0))
623 goto err;
624
625 /* Getting the MD object. */
626 if ((md = EVP_get_digestbyobj((md_alg)->algorithm)EVP_get_digestbyname(OBJ_nid2sn(OBJ_obj2nid((md_alg)->algorithm
)))) == NULL((void*)0)) {
627 TSerror(TS_R_UNSUPPORTED_MD_ALGORITHM)ERR_put_error(47,(0xfff),(126),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,627);
628 goto err;
629 }
630
631 /* Compute message digest. */
632 if ((length = EVP_MD_size(md)) < 0)
633 goto err;
634 imprint_len = length;
635 if ((imprint = malloc(imprint_len)) == NULL((void*)0)) {
636 TSerror(ERR_R_MALLOC_FAILURE)ERR_put_error(47,(0xfff),((1|64)),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,636);
637 goto err;
638 }
639
640 if (!EVP_DigestInit(&md_ctx, md))
641 goto err;
642 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) {
643 if (!EVP_DigestUpdate(&md_ctx, buffer, length))
644 goto err;
645 }
646 if (!EVP_DigestFinal(&md_ctx, imprint, NULL((void*)0)))
647 goto err;
648
649 *out_md_alg = md_alg;
650 md_alg = NULL((void*)0);
651 *out_imprint = imprint;
652 imprint = NULL((void*)0);
653 *out_imprint_len = imprint_len;
654
655 return 1;
656
657err:
658 X509_ALGOR_free(md_alg);
659 free(imprint);
660 return 0;
661}
662
663static int
664TS_check_imprints(X509_ALGOR *algor_a, unsigned char *imprint_a, unsigned len_a,
665 TS_TST_INFO *tst_info)
666{
667 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info);
668 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b);
669 int ret = 0;
670
671 /* algor_a is optional. */
672 if (algor_a) {
673 /* Compare algorithm OIDs. */
674 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm))
675 goto err;
676
677 /* The parameter must be NULL in both. */
678 if ((algor_a->parameter &&
679 ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL5) ||
680 (algor_b->parameter &&
681 ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL5))
682 goto err;
683 }
684
685 /* Compare octet strings. */
686 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) &&
687 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0;
688
689err:
690 if (!ret)
691 TSerror(TS_R_MESSAGE_IMPRINT_MISMATCH)ERR_put_error(47,(0xfff),(103),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,691);
692 return ret;
693}
694
695static int
696TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info)
697{
698 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info);
699
700 /* Error if nonce is missing. */
701 if (!b) {
702 TSerror(TS_R_NONCE_NOT_RETURNED)ERR_put_error(47,(0xfff),(105),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,702);
703 return 0;
704 }
705
706 /* No error if a nonce is returned without being requested. */
707 if (ASN1_INTEGER_cmp(a, b) != 0) {
708 TSerror(TS_R_NONCE_MISMATCH)ERR_put_error(47,(0xfff),(104),"/usr/src/lib/libcrypto/ts/ts_rsp_verify.c"
,708);
709 return 0;
710 }
711
712 return 1;
713}
714
715/* Check if the specified TSA name matches either the subject
716 or one of the subject alternative names of the TSA certificate. */
717static int
718TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer)
719{
720 STACK_OF(GENERAL_NAME)struct stack_st_GENERAL_NAME *gen_names = NULL((void*)0);
721 int idx = -1;
722 int found = 0;
723
724 if (signer == NULL((void*)0))
725 return 0;
726
727 /* Check the subject name first. */
728 if (tsa_name->type == GEN_DIRNAME4 &&
729 X509_NAME_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0)
730 return 1;
731
732 /* Check all the alternative names. */
733 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name85,
734 NULL((void*)0), &idx);
735 while (gen_names != NULL((void*)0) &&
736 !(found = (TS_find_name(gen_names, tsa_name) >= 0))) {
737 /* Get the next subject alternative name,
738 although there should be no more than one. */
739 GENERAL_NAMES_free(gen_names);
740 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name85,
741 NULL((void*)0), &idx);
742 }
743 if (gen_names)
744 GENERAL_NAMES_free(gen_names);
745
746 return found;
747}
748
749/* Returns 1 if name is in gen_names, 0 otherwise. */
750static int
751TS_find_name(STACK_OF(GENERAL_NAME)struct stack_st_GENERAL_NAME *gen_names, GENERAL_NAME *name)
752{
753 int i, found;
754 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names)sk_num(((_STACK*) (1 ? (gen_names) : (struct stack_st_GENERAL_NAME
*)0)));
755 ++i) {
756 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i)((GENERAL_NAME *)sk_value(((_STACK*) (1 ? (gen_names) : (struct
stack_st_GENERAL_NAME*)0)), (i)));
757 found = GENERAL_NAME_cmp(current, name) == 0;
758 }
759 return found ? i - 1 : -1;
760}