| File: | utils/ssl_certs.c |
| Warning: | line 194, column 7 Value stored to 'kvlen' is never read |
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| 1 | /* |
| 2 | * Copyright 2020 Vincent Sanders <vince@netsurf-browser.org> |
| 3 | * |
| 4 | * This file is part of NetSurf, http://www.netsurf-browser.org/ |
| 5 | * |
| 6 | * NetSurf is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; version 2 of the License. |
| 9 | * |
| 10 | * NetSurf is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | |
| 19 | /** |
| 20 | * \file |
| 21 | * helpers for X509 certificate chains |
| 22 | */ |
| 23 | |
| 24 | #include <stdlib.h> |
| 25 | #include <stdint.h> |
| 26 | #include <string.h> |
| 27 | #include <nsutils/base64.h> |
| 28 | |
| 29 | #include "utils/errors.h" |
| 30 | #include "utils/log.h" |
| 31 | #include "utils/nsurl.h" |
| 32 | |
| 33 | #include "netsurf/ssl_certs.h" |
| 34 | |
| 35 | /* |
| 36 | * create new certificate chain |
| 37 | * |
| 38 | * exported interface documented in netsurf/ssl_certs.h |
| 39 | */ |
| 40 | nserror |
| 41 | cert_chain_alloc(size_t depth, struct cert_chain **chain_out) |
| 42 | { |
| 43 | struct cert_chain* chain; |
| 44 | |
| 45 | chain = calloc(1, sizeof(struct cert_chain)); |
| 46 | if (chain == NULL((void*)0)) { |
| 47 | return NSERROR_NOMEM; |
| 48 | } |
| 49 | |
| 50 | chain->depth = depth; |
| 51 | |
| 52 | *chain_out = chain; |
| 53 | |
| 54 | return NSERROR_OK; |
| 55 | } |
| 56 | |
| 57 | |
| 58 | /* |
| 59 | * duplicate certificate chain into existing chain |
| 60 | * |
| 61 | * exported interface documented in netsurf/ssl_certs.h |
| 62 | */ |
| 63 | nserror |
| 64 | cert_chain_dup_into(const struct cert_chain *src, struct cert_chain *dst) |
| 65 | { |
| 66 | size_t depth; |
| 67 | for (depth = 0; depth < dst->depth; depth++) { |
| 68 | if (dst->certs[depth].der != NULL((void*)0)) { |
| 69 | free(dst->certs[depth].der); |
| 70 | dst->certs[depth].der = NULL((void*)0); |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | dst->depth = src->depth; |
| 75 | |
| 76 | for (depth = 0; depth < src->depth; depth++) { |
| 77 | dst->certs[depth].err = src->certs[depth].err; |
| 78 | dst->certs[depth].der_length = src->certs[depth].der_length; |
| 79 | if (src->certs[depth].der != NULL((void*)0)) { |
| 80 | dst->certs[depth].der = malloc(src->certs[depth].der_length); |
| 81 | if (dst->certs[depth].der == NULL((void*)0)) { |
| 82 | return NSERROR_NOMEM; |
| 83 | } |
| 84 | memcpy(dst->certs[depth].der, |
| 85 | src->certs[depth].der, |
| 86 | src->certs[depth].der_length); |
| 87 | } |
| 88 | |
| 89 | } |
| 90 | |
| 91 | return NSERROR_OK; |
| 92 | } |
| 93 | |
| 94 | |
| 95 | /* |
| 96 | * duplicate certificate chain |
| 97 | * |
| 98 | * exported interface documented in netsurf/ssl_certs.h |
| 99 | */ |
| 100 | nserror |
| 101 | cert_chain_dup(const struct cert_chain *src, struct cert_chain **dst_out) |
| 102 | { |
| 103 | struct cert_chain* dst; |
| 104 | size_t depth; |
| 105 | nserror res; |
| 106 | |
| 107 | res = cert_chain_alloc(src->depth, &dst); |
| 108 | if (res != NSERROR_OK) { |
| 109 | return res; |
| 110 | } |
| 111 | |
| 112 | for (depth = 0; depth < src->depth; depth++) { |
| 113 | dst->certs[depth].err = src->certs[depth].err; |
| 114 | dst->certs[depth].der_length = src->certs[depth].der_length; |
| 115 | if (src->certs[depth].der != NULL((void*)0)) { |
| 116 | dst->certs[depth].der = malloc(src->certs[depth].der_length); |
| 117 | if (dst->certs[depth].der == NULL((void*)0)) { |
| 118 | cert_chain_free(dst); |
| 119 | return NSERROR_NOMEM; |
| 120 | } |
| 121 | memcpy(dst->certs[depth].der, |
| 122 | src->certs[depth].der, |
| 123 | src->certs[depth].der_length); |
| 124 | } |
| 125 | |
| 126 | } |
| 127 | |
| 128 | *dst_out = dst; |
| 129 | return NSERROR_OK; |
| 130 | } |
| 131 | |
| 132 | |
| 133 | #define MIN_CERT_LEN64 64 |
| 134 | |
| 135 | /** |
| 136 | * process a part of a query extracting the certificate of an error code |
| 137 | */ |
| 138 | static nserror |
| 139 | process_query_section(const char *str, size_t len, struct cert_chain* chain) |
| 140 | { |
| 141 | nsuerror nsures; |
| 142 | |
| 143 | if ((len > (5 + MIN_CERT_LEN64)) && |
| 144 | (strncmp(str, "cert=", 5) == 0)) { |
| 145 | /* possible certificate entry */ |
| 146 | nsures = nsu_base64_decode_alloc_url( |
| 147 | (const uint8_t *)str + 5, |
| 148 | len - 5, |
| 149 | &chain->certs[chain->depth].der, |
| 150 | &chain->certs[chain->depth].der_length); |
| 151 | if (nsures == NSUERROR_OK) { |
| 152 | chain->depth++; |
| 153 | } |
| 154 | } else if ((len > 8) && |
| 155 | (strncmp(str, "certerr=", 8) == 0)) { |
| 156 | /* certificate entry error code */ |
| 157 | if (chain->depth > 0) { |
| 158 | chain->certs[chain->depth - 1].err = strtoul(str + 8, NULL((void*)0), 10); |
| 159 | } |
| 160 | } |
| 161 | return NSERROR_OK; |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * create a certificate chain from a fetch query string |
| 166 | * |
| 167 | * exported interface documented in netsurf/ssl_certs.h |
| 168 | */ |
| 169 | nserror cert_chain_from_query(struct nsurl *url, struct cert_chain **chain_out) |
| 170 | { |
| 171 | struct cert_chain* chain; |
| 172 | nserror res; |
| 173 | char *querystr; |
| 174 | size_t querylen; |
| 175 | size_t kvstart; |
| 176 | size_t kvlen; |
| 177 | |
| 178 | res = nsurl_get(url, NSURL_QUERY, &querystr, &querylen); |
| 179 | if (res != NSERROR_OK) { |
| 180 | return res; |
| 181 | } |
| 182 | |
| 183 | if (querylen < MIN_CERT_LEN64) { |
| 184 | free(querystr); |
| 185 | return NSERROR_NEED_DATA; |
| 186 | } |
| 187 | |
| 188 | res = cert_chain_alloc(0, &chain); |
| 189 | if (res != NSERROR_OK) { |
| 190 | free(querystr); |
| 191 | return res; |
| 192 | } |
| 193 | |
| 194 | for (kvlen = 0, kvstart = 0; kvstart < querylen; kvstart += kvlen) { |
Value stored to 'kvlen' is never read | |
| 195 | /* get query section length */ |
| 196 | kvlen = 0; |
| 197 | while (((kvstart + kvlen) < querylen) && |
| 198 | (querystr[kvstart + kvlen] != '&')) { |
| 199 | kvlen++; |
| 200 | } |
| 201 | |
| 202 | res = process_query_section(querystr + kvstart, kvlen, chain); |
| 203 | if (res != NSERROR_OK) { |
| 204 | break; |
| 205 | } |
| 206 | kvlen++; /* account for & separator */ |
| 207 | } |
| 208 | free(querystr); |
| 209 | |
| 210 | if (chain->depth > 0) { |
| 211 | *chain_out = chain; |
| 212 | } else { |
| 213 | free(chain); |
| 214 | return NSERROR_INVALID; |
| 215 | } |
| 216 | |
| 217 | return NSERROR_OK; |
| 218 | } |
| 219 | |
| 220 | |
| 221 | /* |
| 222 | * create a fetch query string from a certificate chain |
| 223 | * |
| 224 | * exported interface documented in netsurf/ssl_certs.h |
| 225 | */ |
| 226 | nserror cert_chain_to_query(struct cert_chain *chain, struct nsurl **url_out ) |
| 227 | { |
| 228 | nserror res; |
| 229 | nsurl *url; |
| 230 | size_t allocsize; |
| 231 | size_t urlstrlen; |
| 232 | uint8_t *urlstr; |
| 233 | size_t depth; |
| 234 | |
| 235 | allocsize = 20; |
| 236 | for (depth = 0; depth < chain->depth; depth++) { |
| 237 | allocsize += 7; /* allow for &cert= */ |
| 238 | allocsize += 4 * ((chain->certs[depth].der_length + 2) / 3); |
| 239 | if (chain->certs[depth].err != SSL_CERT_ERR_OK) { |
| 240 | allocsize += 20; /* allow for &certerr=4000000000 */ |
| 241 | } |
| 242 | } |
| 243 | |
| 244 | urlstr = malloc(allocsize); |
| 245 | if (urlstr == NULL((void*)0)) { |
| 246 | return NSERROR_NOMEM; |
| 247 | } |
| 248 | |
| 249 | urlstrlen = snprintf((char *)urlstr, allocsize, "about:certificate"); |
| 250 | for (depth = 0; depth < chain->depth; depth++) { |
| 251 | int written; |
| 252 | nsuerror nsures; |
| 253 | size_t output_length; |
| 254 | |
| 255 | written = snprintf((char *)urlstr + urlstrlen, |
| 256 | allocsize - urlstrlen, |
| 257 | "&cert="); |
| 258 | if (written < 0) { |
| 259 | free(urlstr); |
| 260 | return NSERROR_UNKNOWN; |
| 261 | } |
| 262 | if ((size_t)written >= allocsize - urlstrlen) { |
| 263 | free(urlstr); |
| 264 | return NSERROR_UNKNOWN; |
| 265 | } |
| 266 | |
| 267 | urlstrlen += (size_t)written; |
| 268 | |
| 269 | output_length = allocsize - urlstrlen; |
| 270 | nsures = nsu_base64_encode_url( |
| 271 | chain->certs[depth].der, |
| 272 | chain->certs[depth].der_length, |
| 273 | (uint8_t *)urlstr + urlstrlen, |
| 274 | &output_length); |
| 275 | if (nsures != NSUERROR_OK) { |
| 276 | free(urlstr); |
| 277 | return (nserror)nsures; |
| 278 | } |
| 279 | urlstrlen += output_length; |
| 280 | |
| 281 | if (chain->certs[depth].err != SSL_CERT_ERR_OK) { |
| 282 | written = snprintf((char *)urlstr + urlstrlen, |
| 283 | allocsize - urlstrlen, |
| 284 | "&certerr=%d", |
| 285 | chain->certs[depth].err); |
| 286 | if (written < 0) { |
| 287 | free(urlstr); |
| 288 | return NSERROR_UNKNOWN; |
| 289 | } |
| 290 | if ((size_t)written >= allocsize - urlstrlen) { |
| 291 | free(urlstr); |
| 292 | return NSERROR_UNKNOWN; |
| 293 | } |
| 294 | |
| 295 | urlstrlen += (size_t)written; |
| 296 | } |
| 297 | |
| 298 | } |
| 299 | urlstr[17] = '?'; |
| 300 | urlstr[urlstrlen] = 0; |
| 301 | |
| 302 | res = nsurl_create((const char *)urlstr, &url); |
| 303 | free(urlstr); |
| 304 | |
| 305 | if (res == NSERROR_OK) { |
| 306 | *url_out = url; |
| 307 | } |
| 308 | |
| 309 | return res; |
| 310 | } |
| 311 | |
| 312 | /* |
| 313 | * free certificate chain |
| 314 | * |
| 315 | * exported interface documented in netsurf/ssl_certs.h |
| 316 | */ |
| 317 | nserror cert_chain_free(struct cert_chain* chain) |
| 318 | { |
| 319 | size_t depth; |
| 320 | |
| 321 | if (chain != NULL((void*)0)) { |
| 322 | for (depth = 0; depth < chain->depth; depth++) { |
| 323 | if (chain->certs[depth].der != NULL((void*)0)) { |
| 324 | free(chain->certs[depth].der); |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | free(chain); |
| 329 | } |
| 330 | |
| 331 | return NSERROR_OK; |
| 332 | } |
| 333 | |
| 334 | |
| 335 | /* |
| 336 | * calculate storage used of certificate chain |
| 337 | * |
| 338 | * exported interface documented in netsurf/ssl_certs.h |
| 339 | */ |
| 340 | size_t cert_chain_size(const struct cert_chain *chain) |
| 341 | { |
| 342 | size_t size = 0; |
| 343 | size_t depth; |
| 344 | |
| 345 | if (chain != NULL((void*)0)) { |
| 346 | size += sizeof(struct cert_chain); |
| 347 | |
| 348 | for (depth = 0; depth < chain->depth; depth++) { |
| 349 | if (chain->certs[depth].der != NULL((void*)0)) { |
| 350 | size += chain->certs[depth].der_length; |
| 351 | } |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | return size; |
| 356 | } |