1 /*
2 * Copyright 2016-2022 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 #include <stdlib.h>
11 #include <string.h>
12
13 #include <openssl/conf.h>
14 #include <openssl/ct.h>
15 #include <openssl/err.h>
16 #include <openssl/evp.h>
17 #include <openssl/safestack.h>
18
19 #include "internal/cryptlib.h"
20
21 /*
22 * Information about a CT log server.
23 */
24 struct ctlog_st {
25 OSSL_LIB_CTX *libctx;
26 char *propq;
27 char *name;
28 uint8_t log_id[CT_V1_HASHLEN];
29 EVP_PKEY *public_key;
30 };
31
32 /*
33 * A store for multiple CTLOG instances.
34 * It takes ownership of any CTLOG instances added to it.
35 */
36 struct ctlog_store_st {
37 OSSL_LIB_CTX *libctx;
38 char *propq;
39 STACK_OF(CTLOG) *logs;
40 };
41
42 /* The context when loading a CT log list from a CONF file. */
43 typedef struct ctlog_store_load_ctx_st {
44 CTLOG_STORE *log_store;
45 CONF *conf;
46 size_t invalid_log_entries;
47 } CTLOG_STORE_LOAD_CTX;
48
49 /*
50 * Creates an empty context for loading a CT log store.
51 * It should be populated before use.
52 */
53 static CTLOG_STORE_LOAD_CTX *ctlog_store_load_ctx_new(void);
54
55 /*
56 * Deletes a CT log store load context.
57 * Does not delete any of the fields.
58 */
59 static void ctlog_store_load_ctx_free(CTLOG_STORE_LOAD_CTX* ctx);
60
ctlog_store_load_ctx_new(void)61 static CTLOG_STORE_LOAD_CTX *ctlog_store_load_ctx_new(void)
62 {
63 CTLOG_STORE_LOAD_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
64
65 if (ctx == NULL)
66 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
67
68 return ctx;
69 }
70
ctlog_store_load_ctx_free(CTLOG_STORE_LOAD_CTX * ctx)71 static void ctlog_store_load_ctx_free(CTLOG_STORE_LOAD_CTX* ctx)
72 {
73 OPENSSL_free(ctx);
74 }
75
76 /* Converts a log's public key into a SHA256 log ID */
ct_v1_log_id_from_pkey(CTLOG * log,EVP_PKEY * pkey)77 static int ct_v1_log_id_from_pkey(CTLOG *log, EVP_PKEY *pkey)
78 {
79 int ret = 0;
80 unsigned char *pkey_der = NULL;
81 int pkey_der_len = i2d_PUBKEY(pkey, &pkey_der);
82 unsigned int len;
83 EVP_MD *sha256 = NULL;
84
85 if (pkey_der_len <= 0) {
86 ERR_raise(ERR_LIB_CT, CT_R_LOG_KEY_INVALID);
87 goto err;
88 }
89 sha256 = EVP_MD_fetch(log->libctx, "SHA2-256", log->propq);
90 if (sha256 == NULL) {
91 ERR_raise(ERR_LIB_CT, ERR_R_EVP_LIB);
92 goto err;
93 }
94
95 ret = EVP_Digest(pkey_der, pkey_der_len, log->log_id, &len, sha256,
96 NULL);
97 err:
98 EVP_MD_free(sha256);
99 OPENSSL_free(pkey_der);
100 return ret;
101 }
102
CTLOG_STORE_new_ex(OSSL_LIB_CTX * libctx,const char * propq)103 CTLOG_STORE *CTLOG_STORE_new_ex(OSSL_LIB_CTX *libctx, const char *propq)
104 {
105 CTLOG_STORE *ret = OPENSSL_zalloc(sizeof(*ret));
106
107 if (ret == NULL) {
108 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
109 return NULL;
110 }
111
112 ret->libctx = libctx;
113 if (propq != NULL) {
114 ret->propq = OPENSSL_strdup(propq);
115 if (ret->propq == NULL) {
116 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
117 goto err;
118 }
119 }
120
121 ret->logs = sk_CTLOG_new_null();
122 if (ret->logs == NULL) {
123 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
124 goto err;
125 }
126
127 return ret;
128 err:
129 CTLOG_STORE_free(ret);
130 return NULL;
131 }
132
CTLOG_STORE_new(void)133 CTLOG_STORE *CTLOG_STORE_new(void)
134 {
135 return CTLOG_STORE_new_ex(NULL, NULL);
136 }
137
CTLOG_STORE_free(CTLOG_STORE * store)138 void CTLOG_STORE_free(CTLOG_STORE *store)
139 {
140 if (store != NULL) {
141 OPENSSL_free(store->propq);
142 sk_CTLOG_pop_free(store->logs, CTLOG_free);
143 OPENSSL_free(store);
144 }
145 }
146
ctlog_new_from_conf(CTLOG_STORE * store,CTLOG ** ct_log,const CONF * conf,const char * section)147 static int ctlog_new_from_conf(CTLOG_STORE *store, CTLOG **ct_log,
148 const CONF *conf, const char *section)
149 {
150 const char *description = NCONF_get_string(conf, section, "description");
151 char *pkey_base64;
152
153 if (description == NULL) {
154 ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_MISSING_DESCRIPTION);
155 return 0;
156 }
157
158 pkey_base64 = NCONF_get_string(conf, section, "key");
159 if (pkey_base64 == NULL) {
160 ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_MISSING_KEY);
161 return 0;
162 }
163
164 return CTLOG_new_from_base64_ex(ct_log, pkey_base64, description,
165 store->libctx, store->propq);
166 }
167
CTLOG_STORE_load_default_file(CTLOG_STORE * store)168 int CTLOG_STORE_load_default_file(CTLOG_STORE *store)
169 {
170 const char *fpath = ossl_safe_getenv(CTLOG_FILE_EVP);
171
172 if (fpath == NULL)
173 fpath = CTLOG_FILE;
174
175 return CTLOG_STORE_load_file(store, fpath);
176 }
177
178 /*
179 * Called by CONF_parse_list, which stops if this returns <= 0,
180 * Otherwise, one bad log entry would stop loading of any of
181 * the following log entries.
182 * It may stop parsing and returns -1 on any internal (malloc) error.
183 */
ctlog_store_load_log(const char * log_name,int log_name_len,void * arg)184 static int ctlog_store_load_log(const char *log_name, int log_name_len,
185 void *arg)
186 {
187 CTLOG_STORE_LOAD_CTX *load_ctx = arg;
188 CTLOG *ct_log = NULL;
189 /* log_name may not be null-terminated, so fix that before using it */
190 char *tmp;
191 int ret = 0;
192
193 /* log_name will be NULL for empty list entries */
194 if (log_name == NULL)
195 return 1;
196
197 tmp = OPENSSL_strndup(log_name, log_name_len);
198 if (tmp == NULL)
199 goto mem_err;
200
201 ret = ctlog_new_from_conf(load_ctx->log_store, &ct_log, load_ctx->conf, tmp);
202 OPENSSL_free(tmp);
203
204 if (ret < 0) {
205 /* Propagate any internal error */
206 return ret;
207 }
208 if (ret == 0) {
209 /* If we can't load this log, record that fact and skip it */
210 ++load_ctx->invalid_log_entries;
211 return 1;
212 }
213
214 if (!sk_CTLOG_push(load_ctx->log_store->logs, ct_log)) {
215 goto mem_err;
216 }
217 return 1;
218
219 mem_err:
220 CTLOG_free(ct_log);
221 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
222 return -1;
223 }
224
CTLOG_STORE_load_file(CTLOG_STORE * store,const char * file)225 int CTLOG_STORE_load_file(CTLOG_STORE *store, const char *file)
226 {
227 int ret = 0;
228 char *enabled_logs;
229 CTLOG_STORE_LOAD_CTX* load_ctx = ctlog_store_load_ctx_new();
230
231 if (load_ctx == NULL)
232 return 0;
233 load_ctx->log_store = store;
234 load_ctx->conf = NCONF_new(NULL);
235 if (load_ctx->conf == NULL)
236 goto end;
237
238 if (NCONF_load(load_ctx->conf, file, NULL) <= 0) {
239 ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_INVALID);
240 goto end;
241 }
242
243 enabled_logs = NCONF_get_string(load_ctx->conf, NULL, "enabled_logs");
244 if (enabled_logs == NULL) {
245 ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_INVALID);
246 goto end;
247 }
248
249 if (!CONF_parse_list(enabled_logs, ',', 1, ctlog_store_load_log, load_ctx) ||
250 load_ctx->invalid_log_entries > 0) {
251 ERR_raise(ERR_LIB_CT, CT_R_LOG_CONF_INVALID);
252 goto end;
253 }
254
255 ret = 1;
256 end:
257 NCONF_free(load_ctx->conf);
258 ctlog_store_load_ctx_free(load_ctx);
259 return ret;
260 }
261
262 /*
263 * Initialize a new CTLOG object.
264 * Takes ownership of the public key.
265 * Copies the name.
266 */
CTLOG_new_ex(EVP_PKEY * public_key,const char * name,OSSL_LIB_CTX * libctx,const char * propq)267 CTLOG *CTLOG_new_ex(EVP_PKEY *public_key, const char *name, OSSL_LIB_CTX *libctx,
268 const char *propq)
269 {
270 CTLOG *ret = OPENSSL_zalloc(sizeof(*ret));
271
272 if (ret == NULL) {
273 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
274 return NULL;
275 }
276
277 ret->libctx = libctx;
278 if (propq != NULL) {
279 ret->propq = OPENSSL_strdup(propq);
280 if (ret->propq == NULL) {
281 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
282 goto err;
283 }
284 }
285
286 ret->name = OPENSSL_strdup(name);
287 if (ret->name == NULL) {
288 ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
289 goto err;
290 }
291
292 if (ct_v1_log_id_from_pkey(ret, public_key) != 1)
293 goto err;
294
295 ret->public_key = public_key;
296 return ret;
297 err:
298 CTLOG_free(ret);
299 return NULL;
300 }
301
CTLOG_new(EVP_PKEY * public_key,const char * name)302 CTLOG *CTLOG_new(EVP_PKEY *public_key, const char *name)
303 {
304 return CTLOG_new_ex(public_key, name, NULL, NULL);
305 }
306
307 /* Frees CT log and associated structures */
CTLOG_free(CTLOG * log)308 void CTLOG_free(CTLOG *log)
309 {
310 if (log != NULL) {
311 OPENSSL_free(log->name);
312 EVP_PKEY_free(log->public_key);
313 OPENSSL_free(log->propq);
314 OPENSSL_free(log);
315 }
316 }
317
CTLOG_get0_name(const CTLOG * log)318 const char *CTLOG_get0_name(const CTLOG *log)
319 {
320 return log->name;
321 }
322
CTLOG_get0_log_id(const CTLOG * log,const uint8_t ** log_id,size_t * log_id_len)323 void CTLOG_get0_log_id(const CTLOG *log, const uint8_t **log_id,
324 size_t *log_id_len)
325 {
326 *log_id = log->log_id;
327 *log_id_len = CT_V1_HASHLEN;
328 }
329
CTLOG_get0_public_key(const CTLOG * log)330 EVP_PKEY *CTLOG_get0_public_key(const CTLOG *log)
331 {
332 return log->public_key;
333 }
334
335 /*
336 * Given a log ID, finds the matching log.
337 * Returns NULL if no match found.
338 */
CTLOG_STORE_get0_log_by_id(const CTLOG_STORE * store,const uint8_t * log_id,size_t log_id_len)339 const CTLOG *CTLOG_STORE_get0_log_by_id(const CTLOG_STORE *store,
340 const uint8_t *log_id,
341 size_t log_id_len)
342 {
343 int i;
344
345 for (i = 0; i < sk_CTLOG_num(store->logs); ++i) {
346 const CTLOG *log = sk_CTLOG_value(store->logs, i);
347 if (memcmp(log->log_id, log_id, log_id_len) == 0)
348 return log;
349 }
350
351 return NULL;
352 }
353