1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* X.509 certificate parser 3 * 4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #define pr_fmt(fmt) "X.509: "fmt 9 #include <linux/kernel.h> 10 #include <linux/export.h> 11 #include <linux/slab.h> 12 #include <linux/err.h> 13 #include <linux/oid_registry.h> 14 #include <crypto/public_key.h> 15 #include "x509_parser.h" 16 #include "x509.asn1.h" 17 #include "x509_akid.asn1.h" 18 19 struct x509_parse_context { 20 struct x509_certificate *cert; /* Certificate being constructed */ 21 unsigned long data; /* Start of data */ 22 const void *key; /* Key data */ 23 size_t key_size; /* Size of key data */ 24 const void *params; /* Key parameters */ 25 size_t params_size; /* Size of key parameters */ 26 enum OID key_algo; /* Algorithm used by the cert's key */ 27 enum OID last_oid; /* Last OID encountered */ 28 enum OID sig_algo; /* Algorithm used to sign the cert */ 29 u8 o_size; /* Size of organizationName (O) */ 30 u8 cn_size; /* Size of commonName (CN) */ 31 u8 email_size; /* Size of emailAddress */ 32 u16 o_offset; /* Offset of organizationName (O) */ 33 u16 cn_offset; /* Offset of commonName (CN) */ 34 u16 email_offset; /* Offset of emailAddress */ 35 unsigned raw_akid_size; 36 const void *raw_akid; /* Raw authorityKeyId in ASN.1 */ 37 const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */ 38 unsigned akid_raw_issuer_size; 39 }; 40 41 /* 42 * Free an X.509 certificate 43 */ 44 void x509_free_certificate(struct x509_certificate *cert) 45 { 46 if (cert) { 47 public_key_free(cert->pub); 48 public_key_signature_free(cert->sig); 49 kfree(cert->issuer); 50 kfree(cert->subject); 51 kfree(cert->id); 52 kfree(cert->skid); 53 kfree(cert); 54 } 55 } 56 EXPORT_SYMBOL_GPL(x509_free_certificate); 57 58 /* 59 * Parse an X.509 certificate 60 */ 61 struct x509_certificate *x509_cert_parse(const void *data, size_t datalen) 62 { 63 struct x509_certificate *cert __free(x509_free_certificate); 64 struct x509_parse_context *ctx __free(kfree) = NULL; 65 struct asymmetric_key_id *kid; 66 long ret; 67 68 cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL); 69 if (!cert) 70 return ERR_PTR(-ENOMEM); 71 cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL); 72 if (!cert->pub) 73 return ERR_PTR(-ENOMEM); 74 cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL); 75 if (!cert->sig) 76 return ERR_PTR(-ENOMEM); 77 ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL); 78 if (!ctx) 79 return ERR_PTR(-ENOMEM); 80 81 ctx->cert = cert; 82 ctx->data = (unsigned long)data; 83 84 /* Attempt to decode the certificate */ 85 ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen); 86 if (ret < 0) 87 return ERR_PTR(ret); 88 89 /* Decode the AuthorityKeyIdentifier */ 90 if (ctx->raw_akid) { 91 pr_devel("AKID: %u %*phN\n", 92 ctx->raw_akid_size, ctx->raw_akid_size, ctx->raw_akid); 93 ret = asn1_ber_decoder(&x509_akid_decoder, ctx, 94 ctx->raw_akid, ctx->raw_akid_size); 95 if (ret < 0) { 96 pr_warn("Couldn't decode AuthKeyIdentifier\n"); 97 return ERR_PTR(ret); 98 } 99 } 100 101 cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL); 102 if (!cert->pub->key) 103 return ERR_PTR(-ENOMEM); 104 105 cert->pub->keylen = ctx->key_size; 106 107 cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL); 108 if (!cert->pub->params) 109 return ERR_PTR(-ENOMEM); 110 111 cert->pub->paramlen = ctx->params_size; 112 cert->pub->algo = ctx->key_algo; 113 114 /* Grab the signature bits */ 115 ret = x509_get_sig_params(cert); 116 if (ret < 0) 117 return ERR_PTR(ret); 118 119 /* Generate cert issuer + serial number key ID */ 120 kid = asymmetric_key_generate_id(cert->raw_serial, 121 cert->raw_serial_size, 122 cert->raw_issuer, 123 cert->raw_issuer_size); 124 if (IS_ERR(kid)) 125 return ERR_CAST(kid); 126 cert->id = kid; 127 128 /* Detect self-signed certificates */ 129 ret = x509_check_for_self_signed(cert); 130 if (ret < 0) 131 return ERR_PTR(ret); 132 133 return_ptr(cert); 134 } 135 EXPORT_SYMBOL_GPL(x509_cert_parse); 136 137 /* 138 * Note an OID when we find one for later processing when we know how 139 * to interpret it. 140 */ 141 int x509_note_OID(void *context, size_t hdrlen, 142 unsigned char tag, 143 const void *value, size_t vlen) 144 { 145 struct x509_parse_context *ctx = context; 146 147 ctx->last_oid = look_up_OID(value, vlen); 148 if (ctx->last_oid == OID__NR) { 149 char buffer[50]; 150 sprint_oid(value, vlen, buffer, sizeof(buffer)); 151 pr_debug("Unknown OID: [%lu] %s\n", 152 (unsigned long)value - ctx->data, buffer); 153 } 154 return 0; 155 } 156 157 /* 158 * Save the position of the TBS data so that we can check the signature over it 159 * later. 160 */ 161 int x509_note_tbs_certificate(void *context, size_t hdrlen, 162 unsigned char tag, 163 const void *value, size_t vlen) 164 { 165 struct x509_parse_context *ctx = context; 166 167 pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n", 168 hdrlen, tag, (unsigned long)value - ctx->data, vlen); 169 170 ctx->cert->tbs = value - hdrlen; 171 ctx->cert->tbs_size = vlen + hdrlen; 172 return 0; 173 } 174 175 /* 176 * Record the algorithm that was used to sign this certificate. 177 */ 178 int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag, 179 const void *value, size_t vlen) 180 { 181 struct x509_parse_context *ctx = context; 182 183 pr_debug("PubKey Algo: %u\n", ctx->last_oid); 184 185 switch (ctx->last_oid) { 186 default: 187 return -ENOPKG; /* Unsupported combination */ 188 189 case OID_sha1WithRSAEncryption: 190 ctx->cert->sig->hash_algo = "sha1"; 191 goto rsa_pkcs1; 192 193 case OID_sha256WithRSAEncryption: 194 ctx->cert->sig->hash_algo = "sha256"; 195 goto rsa_pkcs1; 196 197 case OID_sha384WithRSAEncryption: 198 ctx->cert->sig->hash_algo = "sha384"; 199 goto rsa_pkcs1; 200 201 case OID_sha512WithRSAEncryption: 202 ctx->cert->sig->hash_algo = "sha512"; 203 goto rsa_pkcs1; 204 205 case OID_sha224WithRSAEncryption: 206 ctx->cert->sig->hash_algo = "sha224"; 207 goto rsa_pkcs1; 208 209 case OID_id_ecdsa_with_sha1: 210 ctx->cert->sig->hash_algo = "sha1"; 211 goto ecdsa; 212 213 case OID_id_rsassa_pkcs1_v1_5_with_sha3_256: 214 ctx->cert->sig->hash_algo = "sha3-256"; 215 goto rsa_pkcs1; 216 217 case OID_id_rsassa_pkcs1_v1_5_with_sha3_384: 218 ctx->cert->sig->hash_algo = "sha3-384"; 219 goto rsa_pkcs1; 220 221 case OID_id_rsassa_pkcs1_v1_5_with_sha3_512: 222 ctx->cert->sig->hash_algo = "sha3-512"; 223 goto rsa_pkcs1; 224 225 case OID_id_ecdsa_with_sha224: 226 ctx->cert->sig->hash_algo = "sha224"; 227 goto ecdsa; 228 229 case OID_id_ecdsa_with_sha256: 230 ctx->cert->sig->hash_algo = "sha256"; 231 goto ecdsa; 232 233 case OID_id_ecdsa_with_sha384: 234 ctx->cert->sig->hash_algo = "sha384"; 235 goto ecdsa; 236 237 case OID_id_ecdsa_with_sha512: 238 ctx->cert->sig->hash_algo = "sha512"; 239 goto ecdsa; 240 241 case OID_id_ecdsa_with_sha3_256: 242 ctx->cert->sig->hash_algo = "sha3-256"; 243 goto ecdsa; 244 245 case OID_id_ecdsa_with_sha3_384: 246 ctx->cert->sig->hash_algo = "sha3-384"; 247 goto ecdsa; 248 249 case OID_id_ecdsa_with_sha3_512: 250 ctx->cert->sig->hash_algo = "sha3-512"; 251 goto ecdsa; 252 253 case OID_gost2012Signature256: 254 ctx->cert->sig->hash_algo = "streebog256"; 255 goto ecrdsa; 256 257 case OID_gost2012Signature512: 258 ctx->cert->sig->hash_algo = "streebog512"; 259 goto ecrdsa; 260 261 case OID_SM2_with_SM3: 262 ctx->cert->sig->hash_algo = "sm3"; 263 goto sm2; 264 } 265 266 rsa_pkcs1: 267 ctx->cert->sig->pkey_algo = "rsa"; 268 ctx->cert->sig->encoding = "pkcs1"; 269 ctx->sig_algo = ctx->last_oid; 270 return 0; 271 ecrdsa: 272 ctx->cert->sig->pkey_algo = "ecrdsa"; 273 ctx->cert->sig->encoding = "raw"; 274 ctx->sig_algo = ctx->last_oid; 275 return 0; 276 sm2: 277 ctx->cert->sig->pkey_algo = "sm2"; 278 ctx->cert->sig->encoding = "raw"; 279 ctx->sig_algo = ctx->last_oid; 280 return 0; 281 ecdsa: 282 ctx->cert->sig->pkey_algo = "ecdsa"; 283 ctx->cert->sig->encoding = "x962"; 284 ctx->sig_algo = ctx->last_oid; 285 return 0; 286 } 287 288 /* 289 * Note the whereabouts and type of the signature. 290 */ 291 int x509_note_signature(void *context, size_t hdrlen, 292 unsigned char tag, 293 const void *value, size_t vlen) 294 { 295 struct x509_parse_context *ctx = context; 296 297 pr_debug("Signature: alg=%u, size=%zu\n", ctx->last_oid, vlen); 298 299 /* 300 * In X.509 certificates, the signature's algorithm is stored in two 301 * places: inside the TBSCertificate (the data that is signed), and 302 * alongside the signature. These *must* match. 303 */ 304 if (ctx->last_oid != ctx->sig_algo) { 305 pr_warn("signatureAlgorithm (%u) differs from tbsCertificate.signature (%u)\n", 306 ctx->last_oid, ctx->sig_algo); 307 return -EINVAL; 308 } 309 310 if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 || 311 strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0 || 312 strcmp(ctx->cert->sig->pkey_algo, "sm2") == 0 || 313 strcmp(ctx->cert->sig->pkey_algo, "ecdsa") == 0) { 314 /* Discard the BIT STRING metadata */ 315 if (vlen < 1 || *(const u8 *)value != 0) 316 return -EBADMSG; 317 318 value++; 319 vlen--; 320 } 321 322 ctx->cert->raw_sig = value; 323 ctx->cert->raw_sig_size = vlen; 324 return 0; 325 } 326 327 /* 328 * Note the certificate serial number 329 */ 330 int x509_note_serial(void *context, size_t hdrlen, 331 unsigned char tag, 332 const void *value, size_t vlen) 333 { 334 struct x509_parse_context *ctx = context; 335 ctx->cert->raw_serial = value; 336 ctx->cert->raw_serial_size = vlen; 337 return 0; 338 } 339 340 /* 341 * Note some of the name segments from which we'll fabricate a name. 342 */ 343 int x509_extract_name_segment(void *context, size_t hdrlen, 344 unsigned char tag, 345 const void *value, size_t vlen) 346 { 347 struct x509_parse_context *ctx = context; 348 349 switch (ctx->last_oid) { 350 case OID_commonName: 351 ctx->cn_size = vlen; 352 ctx->cn_offset = (unsigned long)value - ctx->data; 353 break; 354 case OID_organizationName: 355 ctx->o_size = vlen; 356 ctx->o_offset = (unsigned long)value - ctx->data; 357 break; 358 case OID_email_address: 359 ctx->email_size = vlen; 360 ctx->email_offset = (unsigned long)value - ctx->data; 361 break; 362 default: 363 break; 364 } 365 366 return 0; 367 } 368 369 /* 370 * Fabricate and save the issuer and subject names 371 */ 372 static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen, 373 unsigned char tag, 374 char **_name, size_t vlen) 375 { 376 const void *name, *data = (const void *)ctx->data; 377 size_t namesize; 378 char *buffer; 379 380 if (*_name) 381 return -EINVAL; 382 383 /* Empty name string if no material */ 384 if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) { 385 buffer = kmalloc(1, GFP_KERNEL); 386 if (!buffer) 387 return -ENOMEM; 388 buffer[0] = 0; 389 goto done; 390 } 391 392 if (ctx->cn_size && ctx->o_size) { 393 /* Consider combining O and CN, but use only the CN if it is 394 * prefixed by the O, or a significant portion thereof. 395 */ 396 namesize = ctx->cn_size; 397 name = data + ctx->cn_offset; 398 if (ctx->cn_size >= ctx->o_size && 399 memcmp(data + ctx->cn_offset, data + ctx->o_offset, 400 ctx->o_size) == 0) 401 goto single_component; 402 if (ctx->cn_size >= 7 && 403 ctx->o_size >= 7 && 404 memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0) 405 goto single_component; 406 407 buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1, 408 GFP_KERNEL); 409 if (!buffer) 410 return -ENOMEM; 411 412 memcpy(buffer, 413 data + ctx->o_offset, ctx->o_size); 414 buffer[ctx->o_size + 0] = ':'; 415 buffer[ctx->o_size + 1] = ' '; 416 memcpy(buffer + ctx->o_size + 2, 417 data + ctx->cn_offset, ctx->cn_size); 418 buffer[ctx->o_size + 2 + ctx->cn_size] = 0; 419 goto done; 420 421 } else if (ctx->cn_size) { 422 namesize = ctx->cn_size; 423 name = data + ctx->cn_offset; 424 } else if (ctx->o_size) { 425 namesize = ctx->o_size; 426 name = data + ctx->o_offset; 427 } else { 428 namesize = ctx->email_size; 429 name = data + ctx->email_offset; 430 } 431 432 single_component: 433 buffer = kmalloc(namesize + 1, GFP_KERNEL); 434 if (!buffer) 435 return -ENOMEM; 436 memcpy(buffer, name, namesize); 437 buffer[namesize] = 0; 438 439 done: 440 *_name = buffer; 441 ctx->cn_size = 0; 442 ctx->o_size = 0; 443 ctx->email_size = 0; 444 return 0; 445 } 446 447 int x509_note_issuer(void *context, size_t hdrlen, 448 unsigned char tag, 449 const void *value, size_t vlen) 450 { 451 struct x509_parse_context *ctx = context; 452 struct asymmetric_key_id *kid; 453 454 ctx->cert->raw_issuer = value; 455 ctx->cert->raw_issuer_size = vlen; 456 457 if (!ctx->cert->sig->auth_ids[2]) { 458 kid = asymmetric_key_generate_id(value, vlen, "", 0); 459 if (IS_ERR(kid)) 460 return PTR_ERR(kid); 461 ctx->cert->sig->auth_ids[2] = kid; 462 } 463 464 return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen); 465 } 466 467 int x509_note_subject(void *context, size_t hdrlen, 468 unsigned char tag, 469 const void *value, size_t vlen) 470 { 471 struct x509_parse_context *ctx = context; 472 ctx->cert->raw_subject = value; 473 ctx->cert->raw_subject_size = vlen; 474 return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen); 475 } 476 477 /* 478 * Extract the parameters for the public key 479 */ 480 int x509_note_params(void *context, size_t hdrlen, 481 unsigned char tag, 482 const void *value, size_t vlen) 483 { 484 struct x509_parse_context *ctx = context; 485 486 /* 487 * AlgorithmIdentifier is used three times in the x509, we should skip 488 * first and ignore third, using second one which is after subject and 489 * before subjectPublicKey. 490 */ 491 if (!ctx->cert->raw_subject || ctx->key) 492 return 0; 493 ctx->params = value - hdrlen; 494 ctx->params_size = vlen + hdrlen; 495 return 0; 496 } 497 498 /* 499 * Extract the data for the public key algorithm 500 */ 501 int x509_extract_key_data(void *context, size_t hdrlen, 502 unsigned char tag, 503 const void *value, size_t vlen) 504 { 505 struct x509_parse_context *ctx = context; 506 enum OID oid; 507 508 ctx->key_algo = ctx->last_oid; 509 switch (ctx->last_oid) { 510 case OID_rsaEncryption: 511 ctx->cert->pub->pkey_algo = "rsa"; 512 break; 513 case OID_gost2012PKey256: 514 case OID_gost2012PKey512: 515 ctx->cert->pub->pkey_algo = "ecrdsa"; 516 break; 517 case OID_sm2: 518 ctx->cert->pub->pkey_algo = "sm2"; 519 break; 520 case OID_id_ecPublicKey: 521 if (parse_OID(ctx->params, ctx->params_size, &oid) != 0) 522 return -EBADMSG; 523 524 switch (oid) { 525 case OID_sm2: 526 ctx->cert->pub->pkey_algo = "sm2"; 527 break; 528 case OID_id_prime192v1: 529 ctx->cert->pub->pkey_algo = "ecdsa-nist-p192"; 530 break; 531 case OID_id_prime256v1: 532 ctx->cert->pub->pkey_algo = "ecdsa-nist-p256"; 533 break; 534 case OID_id_ansip384r1: 535 ctx->cert->pub->pkey_algo = "ecdsa-nist-p384"; 536 break; 537 case OID_id_ansip521r1: 538 ctx->cert->pub->pkey_algo = "ecdsa-nist-p521"; 539 break; 540 default: 541 return -ENOPKG; 542 } 543 break; 544 default: 545 return -ENOPKG; 546 } 547 548 /* Discard the BIT STRING metadata */ 549 if (vlen < 1 || *(const u8 *)value != 0) 550 return -EBADMSG; 551 ctx->key = value + 1; 552 ctx->key_size = vlen - 1; 553 return 0; 554 } 555 556 /* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */ 557 #define SEQ_TAG_KEYID (ASN1_CONT << 6) 558 559 /* 560 * Process certificate extensions that are used to qualify the certificate. 561 */ 562 int x509_process_extension(void *context, size_t hdrlen, 563 unsigned char tag, 564 const void *value, size_t vlen) 565 { 566 struct x509_parse_context *ctx = context; 567 struct asymmetric_key_id *kid; 568 const unsigned char *v = value; 569 570 pr_debug("Extension: %u\n", ctx->last_oid); 571 572 if (ctx->last_oid == OID_subjectKeyIdentifier) { 573 /* Get hold of the key fingerprint */ 574 if (ctx->cert->skid || vlen < 3) 575 return -EBADMSG; 576 if (v[0] != ASN1_OTS || v[1] != vlen - 2) 577 return -EBADMSG; 578 v += 2; 579 vlen -= 2; 580 581 ctx->cert->raw_skid_size = vlen; 582 ctx->cert->raw_skid = v; 583 kid = asymmetric_key_generate_id(v, vlen, "", 0); 584 if (IS_ERR(kid)) 585 return PTR_ERR(kid); 586 ctx->cert->skid = kid; 587 pr_debug("subjkeyid %*phN\n", kid->len, kid->data); 588 return 0; 589 } 590 591 if (ctx->last_oid == OID_keyUsage) { 592 /* 593 * Get hold of the keyUsage bit string 594 * v[1] is the encoding size 595 * (Expect either 0x02 or 0x03, making it 1 or 2 bytes) 596 * v[2] is the number of unused bits in the bit string 597 * (If >= 3 keyCertSign is missing when v[1] = 0x02) 598 * v[3] and possibly v[4] contain the bit string 599 * 600 * From RFC 5280 4.2.1.3: 601 * 0x04 is where keyCertSign lands in this bit string 602 * 0x80 is where digitalSignature lands in this bit string 603 */ 604 if (v[0] != ASN1_BTS) 605 return -EBADMSG; 606 if (vlen < 4) 607 return -EBADMSG; 608 if (v[2] >= 8) 609 return -EBADMSG; 610 if (v[3] & 0x80) 611 ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_DIGITALSIG; 612 if (v[1] == 0x02 && v[2] <= 2 && (v[3] & 0x04)) 613 ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_KEYCERTSIGN; 614 else if (vlen > 4 && v[1] == 0x03 && (v[3] & 0x04)) 615 ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_KEYCERTSIGN; 616 return 0; 617 } 618 619 if (ctx->last_oid == OID_authorityKeyIdentifier) { 620 /* Get hold of the CA key fingerprint */ 621 ctx->raw_akid = v; 622 ctx->raw_akid_size = vlen; 623 return 0; 624 } 625 626 if (ctx->last_oid == OID_basicConstraints) { 627 /* 628 * Get hold of the basicConstraints 629 * v[1] is the encoding size 630 * (Expect 0x2 or greater, making it 1 or more bytes) 631 * v[2] is the encoding type 632 * (Expect an ASN1_BOOL for the CA) 633 * v[3] is the contents of the ASN1_BOOL 634 * (Expect 1 if the CA is TRUE) 635 * vlen should match the entire extension size 636 */ 637 if (v[0] != (ASN1_CONS_BIT | ASN1_SEQ)) 638 return -EBADMSG; 639 if (vlen < 2) 640 return -EBADMSG; 641 if (v[1] != vlen - 2) 642 return -EBADMSG; 643 if (vlen >= 4 && v[1] != 0 && v[2] == ASN1_BOOL && v[3] == 1) 644 ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_CA; 645 return 0; 646 } 647 648 return 0; 649 } 650 651 /** 652 * x509_decode_time - Decode an X.509 time ASN.1 object 653 * @_t: The time to fill in 654 * @hdrlen: The length of the object header 655 * @tag: The object tag 656 * @value: The object value 657 * @vlen: The size of the object value 658 * 659 * Decode an ASN.1 universal time or generalised time field into a struct the 660 * kernel can handle and check it for validity. The time is decoded thus: 661 * 662 * [RFC5280 §4.1.2.5] 663 * CAs conforming to this profile MUST always encode certificate validity 664 * dates through the year 2049 as UTCTime; certificate validity dates in 665 * 2050 or later MUST be encoded as GeneralizedTime. Conforming 666 * applications MUST be able to process validity dates that are encoded in 667 * either UTCTime or GeneralizedTime. 668 */ 669 int x509_decode_time(time64_t *_t, size_t hdrlen, 670 unsigned char tag, 671 const unsigned char *value, size_t vlen) 672 { 673 static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30, 674 31, 31, 30, 31, 30, 31 }; 675 const unsigned char *p = value; 676 unsigned year, mon, day, hour, min, sec, mon_len; 677 678 #define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; }) 679 #define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; }) 680 681 if (tag == ASN1_UNITIM) { 682 /* UTCTime: YYMMDDHHMMSSZ */ 683 if (vlen != 13) 684 goto unsupported_time; 685 year = DD2bin(p); 686 if (year >= 50) 687 year += 1900; 688 else 689 year += 2000; 690 } else if (tag == ASN1_GENTIM) { 691 /* GenTime: YYYYMMDDHHMMSSZ */ 692 if (vlen != 15) 693 goto unsupported_time; 694 year = DD2bin(p) * 100 + DD2bin(p); 695 if (year >= 1950 && year <= 2049) 696 goto invalid_time; 697 } else { 698 goto unsupported_time; 699 } 700 701 mon = DD2bin(p); 702 day = DD2bin(p); 703 hour = DD2bin(p); 704 min = DD2bin(p); 705 sec = DD2bin(p); 706 707 if (*p != 'Z') 708 goto unsupported_time; 709 710 if (year < 1970 || 711 mon < 1 || mon > 12) 712 goto invalid_time; 713 714 mon_len = month_lengths[mon - 1]; 715 if (mon == 2) { 716 if (year % 4 == 0) { 717 mon_len = 29; 718 if (year % 100 == 0) { 719 mon_len = 28; 720 if (year % 400 == 0) 721 mon_len = 29; 722 } 723 } 724 } 725 726 if (day < 1 || day > mon_len || 727 hour > 24 || /* ISO 8601 permits 24:00:00 as midnight tomorrow */ 728 min > 59 || 729 sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */ 730 goto invalid_time; 731 732 *_t = mktime64(year, mon, day, hour, min, sec); 733 return 0; 734 735 unsupported_time: 736 pr_debug("Got unsupported time [tag %02x]: '%*phN'\n", 737 tag, (int)vlen, value); 738 return -EBADMSG; 739 invalid_time: 740 pr_debug("Got invalid time [tag %02x]: '%*phN'\n", 741 tag, (int)vlen, value); 742 return -EBADMSG; 743 } 744 EXPORT_SYMBOL_GPL(x509_decode_time); 745 746 int x509_note_not_before(void *context, size_t hdrlen, 747 unsigned char tag, 748 const void *value, size_t vlen) 749 { 750 struct x509_parse_context *ctx = context; 751 return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen); 752 } 753 754 int x509_note_not_after(void *context, size_t hdrlen, 755 unsigned char tag, 756 const void *value, size_t vlen) 757 { 758 struct x509_parse_context *ctx = context; 759 return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen); 760 } 761 762 /* 763 * Note a key identifier-based AuthorityKeyIdentifier 764 */ 765 int x509_akid_note_kid(void *context, size_t hdrlen, 766 unsigned char tag, 767 const void *value, size_t vlen) 768 { 769 struct x509_parse_context *ctx = context; 770 struct asymmetric_key_id *kid; 771 772 pr_debug("AKID: keyid: %*phN\n", (int)vlen, value); 773 774 if (ctx->cert->sig->auth_ids[1]) 775 return 0; 776 777 kid = asymmetric_key_generate_id(value, vlen, "", 0); 778 if (IS_ERR(kid)) 779 return PTR_ERR(kid); 780 pr_debug("authkeyid %*phN\n", kid->len, kid->data); 781 ctx->cert->sig->auth_ids[1] = kid; 782 return 0; 783 } 784 785 /* 786 * Note a directoryName in an AuthorityKeyIdentifier 787 */ 788 int x509_akid_note_name(void *context, size_t hdrlen, 789 unsigned char tag, 790 const void *value, size_t vlen) 791 { 792 struct x509_parse_context *ctx = context; 793 794 pr_debug("AKID: name: %*phN\n", (int)vlen, value); 795 796 ctx->akid_raw_issuer = value; 797 ctx->akid_raw_issuer_size = vlen; 798 return 0; 799 } 800 801 /* 802 * Note a serial number in an AuthorityKeyIdentifier 803 */ 804 int x509_akid_note_serial(void *context, size_t hdrlen, 805 unsigned char tag, 806 const void *value, size_t vlen) 807 { 808 struct x509_parse_context *ctx = context; 809 struct asymmetric_key_id *kid; 810 811 pr_debug("AKID: serial: %*phN\n", (int)vlen, value); 812 813 if (!ctx->akid_raw_issuer || ctx->cert->sig->auth_ids[0]) 814 return 0; 815 816 kid = asymmetric_key_generate_id(value, 817 vlen, 818 ctx->akid_raw_issuer, 819 ctx->akid_raw_issuer_size); 820 if (IS_ERR(kid)) 821 return PTR_ERR(kid); 822 823 pr_debug("authkeyid %*phN\n", kid->len, kid->data); 824 ctx->cert->sig->auth_ids[0] = kid; 825 return 0; 826 } 827