1/*
2 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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#ifdef OPENSSL_NO_CT
11# error "CT disabled"
12#endif
13
14#include <openssl/ct.h>
15#include <openssl/err.h>
16#include <openssl/evp.h>
17#include <openssl/tls1.h>
18#include <openssl/x509.h>
19
20#include "ct_local.h"
21
22SCT *SCT_new(void)
23{
24 SCT *sct = OPENSSL_zalloc(sizeof(*sct));
25
26 if (sct == NULL) {
27 CTerr(CT_F_SCT_NEW, ERR_R_MALLOC_FAILURE);
28 return NULL;
29 }
30
31 sct->entry_type = CT_LOG_ENTRY_TYPE_NOT_SET;
32 sct->version = SCT_VERSION_NOT_SET;
33 return sct;
34}
35
36void SCT_free(SCT *sct)
37{
38 if (sct == NULL)
39 return;
40
41 OPENSSL_free(sct->log_id);
42 OPENSSL_free(sct->ext);
43 OPENSSL_free(sct->sig);
44 OPENSSL_free(sct->sct);
45 OPENSSL_free(sct);
46}
47
48void SCT_LIST_free(STACK_OF(SCT) *a)
49{
50 sk_SCT_pop_free(a, SCT_free);
51}
52
53int SCT_set_version(SCT *sct, sct_version_t version)
54{
55 if (version != SCT_VERSION_V1) {
56 CTerr(CT_F_SCT_SET_VERSION, CT_R_UNSUPPORTED_VERSION);
57 return 0;
58 }
59 sct->version = version;
60 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
61 return 1;
62}
63
64int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type)
65{
66 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
67
68 switch (entry_type) {
69 case CT_LOG_ENTRY_TYPE_X509:
70 case CT_LOG_ENTRY_TYPE_PRECERT:
71 sct->entry_type = entry_type;
72 return 1;
73 case CT_LOG_ENTRY_TYPE_NOT_SET:
74 break;
75 }
76 CTerr(CT_F_SCT_SET_LOG_ENTRY_TYPE, CT_R_UNSUPPORTED_ENTRY_TYPE);
77 return 0;
78}
79
80int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len)
81{
82 if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) {
83 CTerr(CT_F_SCT_SET0_LOG_ID, CT_R_INVALID_LOG_ID_LENGTH);
84 return 0;
85 }
86
87 OPENSSL_free(sct->log_id);
88 sct->log_id = log_id;
89 sct->log_id_len = log_id_len;
90 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
91 return 1;
92}
93
94int SCT_set1_log_id(SCT *sct, const unsigned char *log_id, size_t log_id_len)
95{
96 if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) {
97 CTerr(CT_F_SCT_SET1_LOG_ID, CT_R_INVALID_LOG_ID_LENGTH);
98 return 0;
99 }
100
101 OPENSSL_free(sct->log_id);
102 sct->log_id = NULL;
103 sct->log_id_len = 0;
104 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
105
106 if (log_id != NULL && log_id_len > 0) {
107 sct->log_id = OPENSSL_memdup(log_id, log_id_len);
108 if (sct->log_id == NULL) {
109 CTerr(CT_F_SCT_SET1_LOG_ID, ERR_R_MALLOC_FAILURE);
110 return 0;
111 }
112 sct->log_id_len = log_id_len;
113 }
114 return 1;
115}
116
117
118void SCT_set_timestamp(SCT *sct, uint64_t timestamp)
119{
120 sct->timestamp = timestamp;
121 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
122}
123
124int SCT_set_signature_nid(SCT *sct, int nid)
125{
126 switch (nid) {
127 case NID_sha256WithRSAEncryption:
128 sct->hash_alg = TLSEXT_hash_sha256;
129 sct->sig_alg = TLSEXT_signature_rsa;
130 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
131 return 1;
132 case NID_ecdsa_with_SHA256:
133 sct->hash_alg = TLSEXT_hash_sha256;
134 sct->sig_alg = TLSEXT_signature_ecdsa;
135 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
136 return 1;
137 default:
138 CTerr(CT_F_SCT_SET_SIGNATURE_NID, CT_R_UNRECOGNIZED_SIGNATURE_NID);
139 return 0;
140 }
141}
142
143void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len)
144{
145 OPENSSL_free(sct->ext);
146 sct->ext = ext;
147 sct->ext_len = ext_len;
148 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
149}
150
151int SCT_set1_extensions(SCT *sct, const unsigned char *ext, size_t ext_len)
152{
153 OPENSSL_free(sct->ext);
154 sct->ext = NULL;
155 sct->ext_len = 0;
156 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
157
158 if (ext != NULL && ext_len > 0) {
159 sct->ext = OPENSSL_memdup(ext, ext_len);
160 if (sct->ext == NULL) {
161 CTerr(CT_F_SCT_SET1_EXTENSIONS, ERR_R_MALLOC_FAILURE);
162 return 0;
163 }
164 sct->ext_len = ext_len;
165 }
166 return 1;
167}
168
169void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len)
170{
171 OPENSSL_free(sct->sig);
172 sct->sig = sig;
173 sct->sig_len = sig_len;
174 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
175}
176
177int SCT_set1_signature(SCT *sct, const unsigned char *sig, size_t sig_len)
178{
179 OPENSSL_free(sct->sig);
180 sct->sig = NULL;
181 sct->sig_len = 0;
182 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
183
184 if (sig != NULL && sig_len > 0) {
185 sct->sig = OPENSSL_memdup(sig, sig_len);
186 if (sct->sig == NULL) {
187 CTerr(CT_F_SCT_SET1_SIGNATURE, ERR_R_MALLOC_FAILURE);
188 return 0;
189 }
190 sct->sig_len = sig_len;
191 }
192 return 1;
193}
194
195sct_version_t SCT_get_version(const SCT *sct)
196{
197 return sct->version;
198}
199
200ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct)
201{
202 return sct->entry_type;
203}
204
205size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id)
206{
207 *log_id = sct->log_id;
208 return sct->log_id_len;
209}
210
211uint64_t SCT_get_timestamp(const SCT *sct)
212{
213 return sct->timestamp;
214}
215
216int SCT_get_signature_nid(const SCT *sct)
217{
218 if (sct->version == SCT_VERSION_V1) {
219 if (sct->hash_alg == TLSEXT_hash_sha256) {
220 switch (sct->sig_alg) {
221 case TLSEXT_signature_ecdsa:
222 return NID_ecdsa_with_SHA256;
223 case TLSEXT_signature_rsa:
224 return NID_sha256WithRSAEncryption;
225 default:
226 return NID_undef;
227 }
228 }
229 }
230 return NID_undef;
231}
232
233size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext)
234{
235 *ext = sct->ext;
236 return sct->ext_len;
237}
238
239size_t SCT_get0_signature(const SCT *sct, unsigned char **sig)
240{
241 *sig = sct->sig;
242 return sct->sig_len;
243}
244
245int SCT_is_complete(const SCT *sct)
246{
247 switch (sct->version) {
248 case SCT_VERSION_NOT_SET:
249 return 0;
250 case SCT_VERSION_V1:
251 return sct->log_id != NULL && SCT_signature_is_complete(sct);
252 default:
253 return sct->sct != NULL; /* Just need cached encoding */
254 }
255}
256
257int SCT_signature_is_complete(const SCT *sct)
258{
259 return SCT_get_signature_nid(sct) != NID_undef &&
260 sct->sig != NULL && sct->sig_len > 0;
261}
262
263sct_source_t SCT_get_source(const SCT *sct)
264{
265 return sct->source;
266}
267
268int SCT_set_source(SCT *sct, sct_source_t source)
269{
270 sct->source = source;
271 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
272 switch (source) {
273 case SCT_SOURCE_TLS_EXTENSION:
274 case SCT_SOURCE_OCSP_STAPLED_RESPONSE:
275 return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_X509);
276 case SCT_SOURCE_X509V3_EXTENSION:
277 return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_PRECERT);
278 case SCT_SOURCE_UNKNOWN:
279 break;
280 }
281 /* if we aren't sure, leave the log entry type alone */
282 return 1;
283}
284
285sct_validation_status_t SCT_get_validation_status(const SCT *sct)
286{
287 return sct->validation_status;
288}
289
290int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx)
291{
292 int is_sct_valid = -1;
293 SCT_CTX *sctx = NULL;
294 X509_PUBKEY *pub = NULL, *log_pkey = NULL;
295 const CTLOG *log;
296
297 /*
298 * With an unrecognized SCT version we don't know what such an SCT means,
299 * let alone validate one. So we return validation failure (0).
300 */
301 if (sct->version != SCT_VERSION_V1) {
302 sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_VERSION;
303 return 0;
304 }
305
306 log = CTLOG_STORE_get0_log_by_id(ctx->log_store,
307 sct->log_id, sct->log_id_len);
308
309 /* Similarly, an SCT from an unknown log also cannot be validated. */
310 if (log == NULL) {
311 sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_LOG;
312 return 0;
313 }
314
315 sctx = SCT_CTX_new();
316 if (sctx == NULL)
317 goto err;
318
319 if (X509_PUBKEY_set(&log_pkey, CTLOG_get0_public_key(log)) != 1)
320 goto err;
321 if (SCT_CTX_set1_pubkey(sctx, log_pkey) != 1)
322 goto err;
323
324 if (SCT_get_log_entry_type(sct) == CT_LOG_ENTRY_TYPE_PRECERT) {
325 EVP_PKEY *issuer_pkey;
326
327 if (ctx->issuer == NULL) {
328 sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED;
329 goto end;
330 }
331
332 issuer_pkey = X509_get0_pubkey(ctx->issuer);
333
334 if (X509_PUBKEY_set(&pub, issuer_pkey) != 1)
335 goto err;
336 if (SCT_CTX_set1_issuer_pubkey(sctx, pub) != 1)
337 goto err;
338 }
339
340 SCT_CTX_set_time(sctx, ctx->epoch_time_in_ms);
341
342 /*
343 * XXX: Potential for optimization. This repeats some idempotent heavy
344 * lifting on the certificate for each candidate SCT, and appears to not
345 * use any information in the SCT itself, only the certificate is
346 * processed. So it may make more sense to to do this just once, perhaps
347 * associated with the shared (by all SCTs) policy eval ctx.
348 *
349 * XXX: Failure here is global (SCT independent) and represents either an
350 * issue with the certificate (e.g. duplicate extensions) or an out of
351 * memory condition. When the certificate is incompatible with CT, we just
352 * mark the SCTs invalid, rather than report a failure to determine the
353 * validation status. That way, callbacks that want to do "soft" SCT
354 * processing will not abort handshakes with false positive internal
355 * errors. Since the function does not distinguish between certificate
356 * issues (peer's fault) and internal problems (out fault) the safe thing
357 * to do is to report a validation failure and let the callback or
358 * application decide what to do.
359 */
360 if (SCT_CTX_set1_cert(sctx, ctx->cert, NULL) != 1)
361 sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED;
362 else
363 sct->validation_status = SCT_CTX_verify(sctx, sct) == 1 ?
364 SCT_VALIDATION_STATUS_VALID : SCT_VALIDATION_STATUS_INVALID;
365
366end:
367 is_sct_valid = sct->validation_status == SCT_VALIDATION_STATUS_VALID;
368err:
369 X509_PUBKEY_free(pub);
370 X509_PUBKEY_free(log_pkey);
371 SCT_CTX_free(sctx);
372
373 return is_sct_valid;
374}
375
376int SCT_LIST_validate(const STACK_OF(SCT) *scts, CT_POLICY_EVAL_CTX *ctx)
377{
378 int are_scts_valid = 1;
379 int sct_count = scts != NULL ? sk_SCT_num(scts) : 0;
380 int i;
381
382 for (i = 0; i < sct_count; ++i) {
383 int is_sct_valid = -1;
384 SCT *sct = sk_SCT_value(scts, i);
385
386 if (sct == NULL)
387 continue;
388
389 is_sct_valid = SCT_validate(sct, ctx);
390 if (is_sct_valid < 0)
391 return is_sct_valid;
392 are_scts_valid &= is_sct_valid;
393 }
394
395 return are_scts_valid;
396}
397