1 /*
2 * Copyright 2016-2021 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
SCT_new(void)22 SCT *SCT_new(void)
23 {
24 SCT *sct = OPENSSL_zalloc(sizeof(*sct));
25
26 if (sct == NULL) {
27 ERR_raise(ERR_LIB_CT, 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
SCT_free(SCT * sct)36 void 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
SCT_LIST_free(STACK_OF (SCT)* a)48 void SCT_LIST_free(STACK_OF(SCT) *a)
49 {
50 sk_SCT_pop_free(a, SCT_free);
51 }
52
SCT_set_version(SCT * sct,sct_version_t version)53 int SCT_set_version(SCT *sct, sct_version_t version)
54 {
55 if (version != SCT_VERSION_V1) {
56 ERR_raise(ERR_LIB_CT, 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
SCT_set_log_entry_type(SCT * sct,ct_log_entry_type_t entry_type)64 int 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 ERR_raise(ERR_LIB_CT, CT_R_UNSUPPORTED_ENTRY_TYPE);
77 return 0;
78 }
79
SCT_set0_log_id(SCT * sct,unsigned char * log_id,size_t log_id_len)80 int 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 ERR_raise(ERR_LIB_CT, 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
SCT_set1_log_id(SCT * sct,const unsigned char * log_id,size_t log_id_len)94 int 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 ERR_raise(ERR_LIB_CT, 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 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
110 return 0;
111 }
112 sct->log_id_len = log_id_len;
113 }
114 return 1;
115 }
116
117
SCT_set_timestamp(SCT * sct,uint64_t timestamp)118 void SCT_set_timestamp(SCT *sct, uint64_t timestamp)
119 {
120 sct->timestamp = timestamp;
121 sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
122 }
123
SCT_set_signature_nid(SCT * sct,int nid)124 int 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 ERR_raise(ERR_LIB_CT, CT_R_UNRECOGNIZED_SIGNATURE_NID);
139 return 0;
140 }
141 }
142
SCT_set0_extensions(SCT * sct,unsigned char * ext,size_t ext_len)143 void 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
SCT_set1_extensions(SCT * sct,const unsigned char * ext,size_t ext_len)151 int 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 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
162 return 0;
163 }
164 sct->ext_len = ext_len;
165 }
166 return 1;
167 }
168
SCT_set0_signature(SCT * sct,unsigned char * sig,size_t sig_len)169 void 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
SCT_set1_signature(SCT * sct,const unsigned char * sig,size_t sig_len)177 int 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 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
188 return 0;
189 }
190 sct->sig_len = sig_len;
191 }
192 return 1;
193 }
194
SCT_get_version(const SCT * sct)195 sct_version_t SCT_get_version(const SCT *sct)
196 {
197 return sct->version;
198 }
199
SCT_get_log_entry_type(const SCT * sct)200 ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct)
201 {
202 return sct->entry_type;
203 }
204
SCT_get0_log_id(const SCT * sct,unsigned char ** log_id)205 size_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
SCT_get_timestamp(const SCT * sct)211 uint64_t SCT_get_timestamp(const SCT *sct)
212 {
213 return sct->timestamp;
214 }
215
SCT_get_signature_nid(const SCT * sct)216 int 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
SCT_get0_extensions(const SCT * sct,unsigned char ** ext)233 size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext)
234 {
235 *ext = sct->ext;
236 return sct->ext_len;
237 }
238
SCT_get0_signature(const SCT * sct,unsigned char ** sig)239 size_t SCT_get0_signature(const SCT *sct, unsigned char **sig)
240 {
241 *sig = sct->sig;
242 return sct->sig_len;
243 }
244
SCT_is_complete(const SCT * sct)245 int 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
SCT_signature_is_complete(const SCT * sct)257 int 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
SCT_get_source(const SCT * sct)263 sct_source_t SCT_get_source(const SCT *sct)
264 {
265 return sct->source;
266 }
267
SCT_set_source(SCT * sct,sct_source_t source)268 int 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
SCT_get_validation_status(const SCT * sct)285 sct_validation_status_t SCT_get_validation_status(const SCT *sct)
286 {
287 return sct->validation_status;
288 }
289
SCT_validate(SCT * sct,const CT_POLICY_EVAL_CTX * ctx)290 int 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(ctx->libctx, ctx->propq);
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 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
366 end:
367 is_sct_valid = sct->validation_status == SCT_VALIDATION_STATUS_VALID;
368 err:
369 X509_PUBKEY_free(pub);
370 X509_PUBKEY_free(log_pkey);
371 SCT_CTX_free(sctx);
372
373 return is_sct_valid;
374 }
375
SCT_LIST_validate(const STACK_OF (SCT)* scts,CT_POLICY_EVAL_CTX * ctx)376 int 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