doc/man1/openssl-verify.pod

   1 =pod
   2
   3 =head1 NAME
   4
   5 openssl-verify - Utility to verify certificates
   6
   7 =head1 SYNOPSIS
   8
   9 B<openssl> B<verify>
  10 [B<-help>]
  11 [B<-CAfile file>]
  12 [B<-CApath directory>]
  13 [B<-no-CAfile>]
  14 [B<-no-CApath>]
  15 [B<-allow_proxy_certs>]
  16 [B<-attime timestamp>]
  17 [B<-check_ss_sig>]
  18 [B<-CRLfile file>]
  19 [B<-crl_download>]
  20 [B<-crl_check>]
  21 [B<-crl_check_all>]
  22 [B<-engine id>]
  23 [B<-explicit_policy>]
  24 [B<-extended_crl>]
  25 [B<-ignore_critical>]
  26 [B<-inhibit_any>]
  27 [B<-inhibit_map>]
  28 [B<-nameopt option>]
  29 [B<-no_check_time>]
  30 [B<-partial_chain>]
  31 [B<-policy arg>]
  32 [B<-policy_check>]
  33 [B<-policy_print>]
  34 [B<-purpose purpose>]
  35 [B<-suiteB_128>]
  36 [B<-suiteB_128_only>]
  37 [B<-suiteB_192>]
  38 [B<-trusted_first>]
  39 [B<-no_alt_chains>]
  40 [B<-untrusted file>]
  41 [B<-trusted file>]
  42 [B<-use_deltas>]
  43 [B<-verbose>]
  44 [B<-auth_level level>]
  45 [B<-verify_depth num>]
  46 [B<-verify_email email>]
  47 [B<-verify_hostname hostname>]
  48 [B<-verify_ip ip>]
  49 [B<-verify_name name>]
  50 [B<-x509_strict>]
  51 [B<-show_chain>]
  52 [B<-sm2-id string>]
  53 [B<-sm2-hex-id hex-string>]
  54 [B<->]
  55 [certificates]
  56
  57 =head1 DESCRIPTION
  58
  59 The B<verify> command verifies certificate chains.
  60
  61 =head1 OPTIONS
  62
  63 =over 4
  64
  65 =item B<-help>
  66
  67 Print out a usage message.
  68
  69 =item B<-CAfile file>
  70
  71 A B<file> of trusted certificates.
  72 The file should contain one or more certificates in PEM format.
  73
  74 =item B<-CApath directory>
  75
  76 A directory of trusted certificates. The certificates should have names
  77 of the form: hash.0 or have symbolic links to them of this
  78 form ("hash" is the hashed certificate subject name: see the B<-hash> option
  79 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
  80 create symbolic links to a directory of certificates.
  81
  82 =item B<-no-CAfile>
  83
  84 Do not load the trusted CA certificates from the default file location.
  85
  86 =item B<-no-CApath>
  87
  88 Do not load the trusted CA certificates from the default directory location.
  89
  90 =item B<-allow_proxy_certs>
  91
  92 Allow the verification of proxy certificates.
  93
  94 =item B<-attime timestamp>
  95
  96 Perform validation checks using time specified by B<timestamp> and not
  97 current system time. B<timestamp> is the number of seconds since
  98 01.01.1970 (UNIX time).
  99
 100 =item B<-check_ss_sig>
 101
 102 Verify the signature on the self-signed root CA. This is disabled by default
 103 because it doesn't add any security.
 104
 105 =item B<-CRLfile file>
 106
 107 The B<file> should contain one or more CRLs in PEM format.
 108 This option can be specified more than once to include CRLs from multiple
 109 B<files>.
 110
 111 =item B<-crl_download>
 112
 113 Attempt to download CRL information for this certificate.
 114
 115 =item B<-crl_check>
 116
 117 Checks end entity certificate validity by attempting to look up a valid CRL.
 118 If a valid CRL cannot be found an error occurs.
 119
 120 =item B<-crl_check_all>
 121
 122 Checks the validity of B<all> certificates in the chain by attempting
 123 to look up valid CRLs.
 124
 125 =item B<-engine id>
 126
 127 Specifying an engine B<id> will cause L<verify(1)> to attempt to load the
 128 specified engine.
 129 The engine will then be set as the default for all its supported algorithms.
 130 If you want to load certificates or CRLs that require engine support via any of
 131 the B<-trusted>, B<-untrusted> or B<-CRLfile> options, the B<-engine> option
 132 must be specified before those options.
 133
 134 =item B<-explicit_policy>
 135
 136 Set policy variable require-explicit-policy (see RFC5280).
 137
 138 =item B<-extended_crl>
 139
 140 Enable extended CRL features such as indirect CRLs and alternate CRL
 141 signing keys.
 142
 143 =item B<-ignore_critical>
 144
 145 Normally if an unhandled critical extension is present which is not
 146 supported by OpenSSL the certificate is rejected (as required by RFC5280).
 147 If this option is set critical extensions are ignored.
 148
 149 =item B<-inhibit_any>
 150
 151 Set policy variable inhibit-any-policy (see RFC5280).
 152
 153 =item B<-inhibit_map>
 154
 155 Set policy variable inhibit-policy-mapping (see RFC5280).
 156
 157 =item B<-nameopt option>
 158
 159 Option which determines how the subject or issuer names are displayed. The
 160 B<option> argument can be a single option or multiple options separated by
 161 commas.  Alternatively the B<-nameopt> switch may be used more than once to
 162 set multiple options. See the L<x509(1)> manual page for details.
 163
 164 =item B<-no_check_time>
 165
 166 This option suppresses checking the validity period of certificates and CRLs
 167 against the current time. If option B<-attime timestamp> is used to specify
 168 a verification time, the check is not suppressed.
 169
 170 =item B<-partial_chain>
 171
 172 Allow verification to succeed even if a I<complete> chain cannot be built to a
 173 self-signed trust-anchor, provided it is possible to construct a chain to a
 174 trusted certificate that might not be self-signed.
 175
 176 =item B<-policy arg>
 177
 178 Enable policy processing and add B<arg> to the user-initial-policy-set (see
 179 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
 180 This argument can appear more than once.
 181
 182 =item B<-policy_check>
 183
 184 Enables certificate policy processing.
 185
 186 =item B<-policy_print>
 187
 188 Print out diagnostics related to policy processing.
 189
 190 =item B<-purpose purpose>
 191
 192 The intended use for the certificate. If this option is not specified,
 193 B<verify> will not consider certificate purpose during chain verification.
 194 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
 195 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
 196 information.
 197
 198 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
 199
 200 Enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
 201 192 bit, or only 192 bit Level of Security respectively.
 202 See RFC6460 for details. In particular the supported signature algorithms are
 203 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
 204 P-256 and P-384.
 205
 206 =item B<-trusted_first>
 207
 208 When constructing the certificate chain, use the trusted certificates specified
 209 via B<-CAfile>, B<-CApath> or B<-trusted> before any certificates specified via
 210 B<-untrusted>.
 211 This can be useful in environments with Bridge or Cross-Certified CAs.
 212 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
 213
 214 =item B<-no_alt_chains>
 215
 216 By default, unless B<-trusted_first> is specified, when building a certificate
 217 chain, if the first certificate chain found is not trusted, then OpenSSL will
 218 attempt to replace untrusted issuer certificates with certificates from the
 219 trust store to see if an alternative chain can be found that is trusted.
 220 As of OpenSSL 1.1.0, with B<-trusted_first> always on, this option has no
 221 effect.
 222
 223 =item B<-untrusted file>
 224
 225 A B<file> of additional untrusted certificates (intermediate issuer CAs) used
 226 to construct a certificate chain from the subject certificate to a trust-anchor.
 227 The B<file> should contain one or more certificates in PEM format.
 228 This option can be specified more than once to include untrusted certificates
 229 from multiple B<files>.
 230
 231 =item B<-trusted file>
 232
 233 A B<file> of trusted certificates, which must be self-signed, unless the
 234 B<-partial_chain> option is specified.
 235 The B<file> contains one or more certificates in PEM format.
 236 With this option, no additional (e.g., default) certificate lists are
 237 consulted.
 238 That is, the only trust-anchors are those listed in B<file>.
 239 This option can be specified more than once to include trusted certificates
 240 from multiple B<files>.
 241 This option implies the B<-no-CAfile> and B<-no-CApath> options.
 242 This option cannot be used in combination with either of the B<-CAfile> or
 243 B<-CApath> options.
 244
 245 =item B<-use_deltas>
 246
 247 Enable support for delta CRLs.
 248
 249 =item B<-verbose>
 250
 251 Print extra information about the operations being performed.
 252
 253 =item B<-auth_level level>
 254
 255 Set the certificate chain authentication security level to B<level>.
 256 The authentication security level determines the acceptable signature and
 257 public key strength when verifying certificate chains.
 258 For a certificate chain to validate, the public keys of all the certificates
 259 must meet the specified security B<level>.
 260 The signature algorithm security level is enforced for all the certificates in
 261 the chain except for the chain's I<trust anchor>, which is either directly
 262 trusted or validated by means other than its signature.
 263 See L<SSL_CTX_set_security_level(3)> for the definitions of the available
 264 levels.
 265 The default security level is -1, or "not set".
 266 At security level 0 or lower all algorithms are acceptable.
 267 Security level 1 requires at least 80-bit-equivalent security and is broadly
 268 interoperable, though it will, for example, reject MD5 signatures or RSA keys
 269 shorter than 1024 bits.
 270
 271 =item B<-verify_depth num>
 272
 273 Limit the certificate chain to B<num> intermediate CA certificates.
 274 A maximal depth chain can have up to B<num+2> certificates, since neither the
 275 end-entity certificate nor the trust-anchor certificate count against the
 276 B<-verify_depth> limit.
 277
 278 =item B<-verify_email email>
 279
 280 Verify if the B<email> matches the email address in Subject Alternative Name or
 281 the email in the subject Distinguished Name.
 282
 283 =item B<-verify_hostname hostname>
 284
 285 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
 286 Common Name in the subject certificate.
 287
 288 =item B<-verify_ip ip>
 289
 290 Verify if the B<ip> matches the IP address in Subject Alternative Name of
 291 the subject certificate.
 292
 293 =item B<-verify_name name>
 294
 295 Use default verification policies like trust model and required certificate
 296 policies identified by B<name>.
 297 The trust model determines which auxiliary trust or reject OIDs are applicable
 298 to verifying the given certificate chain.
 299 See the B<-addtrust> and B<-addreject> options of the L<x509(1)> command-line
 300 utility.
 301 Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
 302 B<ssl_client>, B<ssl_server>.
 303 These mimics the combinations of purpose and trust settings used in SSL, CMS
 304 and S/MIME.
 305 As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
 306 specified, so the B<-verify_name> options are functionally equivalent to the
 307 corresponding B<-purpose> settings.
 308
 309 =item B<-x509_strict>
 310
 311 For strict X.509 compliance, disable non-compliant workarounds for broken
 312 certificates.
 313
 314 =item B<-show_chain>
 315
 316 Display information about the certificate chain that has been built (if
 317 successful). Certificates in the chain that came from the untrusted list will be
 318 flagged as "untrusted".
 319
 320 =item B<-sm2-id>
 321
 322 Specify the ID string to use when verifying an SM2 certificate. The ID string is
 323 required by the SM2 signature algorithm for signing and verification.
 324
 325 =item B<-sm2-hex-id>
 326
 327 Specify a binary ID string to use when signing or verifying using an SM2
 328 certificate. The argument for this option is string of hexadecimal digits.
 329
 330 =item B<->
 331
 332 Indicates the last option. All arguments following this are assumed to be
 333 certificate files. This is useful if the first certificate filename begins
 334 with a B<->.
 335
 336 =item B<certificates>
 337
 338 One or more certificates to verify. If no certificates are given, B<verify>
 339 will attempt to read a certificate from standard input. Certificates must be
 340 in PEM format.
 341
 342 =back
 343
 344 =head1 VERIFY OPERATION
 345
 346 The B<verify> program uses the same functions as the internal SSL and S/MIME
 347 verification, therefore this description applies to these verify operations
 348 too.
 349
 350 There is one crucial difference between the verify operations performed
 351 by the B<verify> program: wherever possible an attempt is made to continue
 352 after an error whereas normally the verify operation would halt on the
 353 first error. This allows all the problems with a certificate chain to be
 354 determined.
 355
 356 The verify operation consists of a number of separate steps.
 357
 358 Firstly a certificate chain is built up starting from the supplied certificate
 359 and ending in the root CA.
 360 It is an error if the whole chain cannot be built up.
 361 The chain is built up by looking up the issuers certificate of the current
 362 certificate.
 363 If a certificate is found which is its own issuer it is assumed to be the root
 364 CA.
 365
 366 The process of 'looking up the issuers certificate' itself involves a number of
 367 steps.
 368 After all certificates whose subject name matches the issuer name of the current
 369 certificate are subject to further tests.
 370 The relevant authority key identifier components of the current certificate (if
 371 present) must match the subject key identifier (if present) and issuer and
 372 serial number of the candidate issuer, in addition the keyUsage extension of
 373 the candidate issuer (if present) must permit certificate signing.
 374
 375 The lookup first looks in the list of untrusted certificates and if no match
 376 is found the remaining lookups are from the trusted certificates. The root CA
 377 is always looked up in the trusted certificate list: if the certificate to
 378 verify is a root certificate then an exact match must be found in the trusted
 379 list.
 380
 381 The second operation is to check every untrusted certificate's extensions for
 382 consistency with the supplied purpose. If the B<-purpose> option is not included
 383 then no checks are done. The supplied or "leaf" certificate must have extensions
 384 compatible with the supplied purpose and all other certificates must also be valid
 385 CA certificates. The precise extensions required are described in more detail in
 386 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
 387
 388 The third operation is to check the trust settings on the root CA. The root CA
 389 should be trusted for the supplied purpose.
 390 For compatibility with previous versions of OpenSSL, a certificate with no
 391 trust settings is considered to be valid for all purposes.
 392
 393 The final operation is to check the validity of the certificate chain. The validity
 394 period is checked against the current system time and the notBefore and notAfter
 395 dates in the certificate. The certificate signatures are also checked at this
 396 point.
 397
 398 If all operations complete successfully then certificate is considered valid. If
 399 any operation fails then the certificate is not valid.
 400
 401 =head1 DIAGNOSTICS
 402
 403 When a verify operation fails the output messages can be somewhat cryptic. The
 404 general form of the error message is:
 405
 406  server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
 407  error 24 at 1 depth lookup:invalid CA certificate
 408
 409 The first line contains the name of the certificate being verified followed by
 410 the subject name of the certificate. The second line contains the error number
 411 and the depth. The depth is number of the certificate being verified when a
 412 problem was detected starting with zero for the certificate being verified itself
 413 then 1 for the CA that signed the certificate and so on. Finally a text version
 414 of the error number is presented.
 415
 416 A partial list of the error codes and messages is shown below, this also
 417 includes the name of the error code as defined in the header file x509_vfy.h
 418 Some of the error codes are defined but never returned: these are described
 419 as "unused".
 420
 421 =over 4
 422
 423 =item B<X509_V_OK>
 424
 425 The operation was successful.
 426
 427 =item B<X509_V_ERR_UNSPECIFIED>
 428
 429 Unspecified error; should not happen.
 430
 431 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT>
 432
 433 The issuer certificate of a looked up certificate could not be found. This
 434 normally means the list of trusted certificates is not complete.
 435
 436 =item B<X509_V_ERR_UNABLE_TO_GET_CRL>
 437
 438 The CRL of a certificate could not be found.
 439
 440 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE>
 441
 442 The certificate signature could not be decrypted. This means that the
 443 actual signature value could not be determined rather than it not matching
 444 the expected value, this is only meaningful for RSA keys.
 445
 446 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE>
 447
 448 The CRL signature could not be decrypted: this means that the actual
 449 signature value could not be determined rather than it not matching the
 450 expected value. Unused.
 451
 452 =item B<X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY>
 453
 454 The public key in the certificate SubjectPublicKeyInfo could not be read.
 455
 456 =item B<X509_V_ERR_CERT_SIGNATURE_FAILURE>
 457
 458 The signature of the certificate is invalid.
 459
 460 =item B<X509_V_ERR_CRL_SIGNATURE_FAILURE>
 461
 462 The signature of the certificate is invalid.
 463
 464 =item B<X509_V_ERR_CERT_NOT_YET_VALID>
 465
 466 The certificate is not yet valid: the notBefore date is after the
 467 current time.
 468
 469 =item B<X509_V_ERR_CERT_HAS_EXPIRED>
 470
 471 The certificate has expired: that is the notAfter date is before the
 472 current time.
 473
 474 =item B<X509_V_ERR_CRL_NOT_YET_VALID>
 475
 476 The CRL is not yet valid.
 477
 478 =item B<X509_V_ERR_CRL_HAS_EXPIRED>
 479
 480 The CRL has expired.
 481
 482 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD>
 483
 484 The certificate notBefore field contains an invalid time.
 485
 486 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD>
 487
 488 The certificate notAfter field contains an invalid time.
 489
 490 =item B<X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD>
 491
 492 The CRL lastUpdate field contains an invalid time.
 493
 494 =item B<X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD>
 495
 496 The CRL nextUpdate field contains an invalid time.
 497
 498 =item B<X509_V_ERR_OUT_OF_MEM>
 499
 500 An error occurred trying to allocate memory. This should never happen.
 501
 502 =item B<X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT>
 503
 504 The passed certificate is self-signed and the same certificate cannot
 505 be found in the list of trusted certificates.
 506
 507 =item B<X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN>
 508
 509 The certificate chain could be built up using the untrusted certificates
 510 but the root could not be found locally.
 511
 512 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY>
 513
 514 The issuer certificate could not be found: this occurs if the issuer
 515 certificate of an untrusted certificate cannot be found.
 516
 517 =item B<X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE>
 518
 519 No signatures could be verified because the chain contains only one
 520 certificate and it is not self signed.
 521
 522 =item B<X509_V_ERR_CERT_CHAIN_TOO_LONG>
 523
 524 The certificate chain length is greater than the supplied maximum
 525 depth. Unused.
 526
 527 =item B<X509_V_ERR_CERT_REVOKED>
 528
 529 The certificate has been revoked.
 530
 531 =item B<X509_V_ERR_INVALID_CA>
 532
 533 A CA certificate is invalid. Either it is not a CA or its extensions
 534 are not consistent with the supplied purpose.
 535
 536 =item B<X509_V_ERR_PATH_LENGTH_EXCEEDED>
 537
 538 The basicConstraints pathlength parameter has been exceeded.
 539
 540 =item B<X509_V_ERR_INVALID_PURPOSE>
 541
 542 The supplied certificate cannot be used for the specified purpose.
 543
 544 =item B<X509_V_ERR_CERT_UNTRUSTED>
 545
 546 The root CA is not marked as trusted for the specified purpose.
 547
 548 =item B<X509_V_ERR_CERT_REJECTED>
 549
 550 The root CA is marked to reject the specified purpose.
 551
 552 =item B<X509_V_ERR_SUBJECT_ISSUER_MISMATCH>
 553
 554 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
 555 B<-issuer_checks> option.
 556
 557 =item B<X509_V_ERR_AKID_SKID_MISMATCH>
 558
 559 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
 560 B<-issuer_checks> option.
 561
 562 =item B<X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH>
 563
 564 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
 565 B<-issuer_checks> option.
 566
 567 =item B<X509_V_ERR_KEYUSAGE_NO_CERTSIGN>
 568
 569 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
 570 B<-issuer_checks> option.
 571
 572 =item B<X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER>
 573
 574 Unable to get CRL issuer certificate.
 575
 576 =item B<X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION>
 577
 578 Unhandled critical extension.
 579
 580 =item B<X509_V_ERR_KEYUSAGE_NO_CRL_SIGN>
 581
 582 Key usage does not include CRL signing.
 583
 584 =item B<X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION>
 585
 586 Unhandled critical CRL extension.
 587
 588 =item B<X509_V_ERR_INVALID_NON_CA>
 589
 590 Invalid non-CA certificate has CA markings.
 591
 592 =item B<X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED>
 593
 594 Proxy path length constraint exceeded.
 595
 596 =item B<X509_V_ERR_PROXY_SUBJECT_INVALID>
 597
 598 Proxy certificate subject is invalid.  It MUST be the same as the issuer
 599 with a single CN component added.
 600
 601 =item B<X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE>
 602
 603 Key usage does not include digital signature.
 604
 605 =item B<X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED>
 606
 607 Proxy certificates not allowed, please use B<-allow_proxy_certs>.
 608
 609 =item B<X509_V_ERR_INVALID_EXTENSION>
 610
 611 Invalid or inconsistent certificate extension.
 612
 613 =item B<X509_V_ERR_INVALID_POLICY_EXTENSION>
 614
 615 Invalid or inconsistent certificate policy extension.
 616
 617 =item B<X509_V_ERR_NO_EXPLICIT_POLICY>
 618
 619 No explicit policy.
 620
 621 =item B<X509_V_ERR_DIFFERENT_CRL_SCOPE>
 622
 623 Different CRL scope.
 624
 625 =item B<X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE>
 626
 627 Unsupported extension feature.
 628
 629 =item B<X509_V_ERR_UNNESTED_RESOURCE>
 630
 631 RFC 3779 resource not subset of parent's resources.
 632
 633 =item B<X509_V_ERR_PERMITTED_VIOLATION>
 634
 635 Permitted subtree violation.
 636
 637 =item B<X509_V_ERR_EXCLUDED_VIOLATION>
 638
 639 Excluded subtree violation.
 640
 641 =item B<X509_V_ERR_SUBTREE_MINMAX>
 642
 643 Name constraints minimum and maximum not supported.
 644
 645 =item B<X509_V_ERR_APPLICATION_VERIFICATION>
 646
 647 Application verification failure. Unused.
 648
 649 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE>
 650
 651 Unsupported name constraint type.
 652
 653 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX>
 654
 655 Unsupported or invalid name constraint syntax.
 656
 657 =item B<X509_V_ERR_UNSUPPORTED_NAME_SYNTAX>
 658
 659 Unsupported or invalid name syntax.
 660
 661 =item B<X509_V_ERR_CRL_PATH_VALIDATION_ERROR>
 662
 663 CRL path validation error.
 664
 665 =item B<X509_V_ERR_PATH_LOOP>
 666
 667 Path loop.
 668
 669 =item B<X509_V_ERR_SUITE_B_INVALID_VERSION>
 670
 671 Suite B: certificate version invalid.
 672
 673 =item B<X509_V_ERR_SUITE_B_INVALID_ALGORITHM>
 674
 675 Suite B: invalid public key algorithm.
 676
 677 =item B<X509_V_ERR_SUITE_B_INVALID_CURVE>
 678
 679 Suite B: invalid ECC curve.
 680
 681 =item B<X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM>
 682
 683 Suite B: invalid signature algorithm.
 684
 685 =item B<X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED>
 686
 687 Suite B: curve not allowed for this LOS.
 688
 689 =item B<X509_V_ERR_SUITE_B_CANNOT_SIGN_P_384_WITH_P_256>
 690
 691 Suite B: cannot sign P-384 with P-256.
 692
 693 =item B<X509_V_ERR_HOSTNAME_MISMATCH>
 694
 695 Hostname mismatch.
 696
 697 =item B<X509_V_ERR_EMAIL_MISMATCH>
 698
 699 Email address mismatch.
 700
 701 =item B<X509_V_ERR_IP_ADDRESS_MISMATCH>
 702
 703 IP address mismatch.
 704
 705 =item B<X509_V_ERR_DANE_NO_MATCH>
 706
 707 DANE TLSA authentication is enabled, but no TLSA records matched the
 708 certificate chain.
 709 This error is only possible in L<s_client(1)>.
 710
 711 =item B<X509_V_ERR_EE_KEY_TOO_SMALL>
 712
 713 EE certificate key too weak.
 714
 715 =item B<X509_ERR_CA_KEY_TOO_SMALL>
 716
 717 CA certificate key too weak.
 718
 719 =item B<X509_ERR_CA_MD_TOO_WEAK>
 720
 721 CA signature digest algorithm too weak.
 722
 723 =item B<X509_V_ERR_INVALID_CALL>
 724
 725 nvalid certificate verification context.
 726
 727 =item B<X509_V_ERR_STORE_LOOKUP>
 728
 729 Issuer certificate lookup error.
 730
 731 =item B<X509_V_ERR_NO_VALID_SCTS>
 732
 733 Certificate Transparency required, but no valid SCTs found.
 734
 735 =item B<X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION>
 736
 737 Proxy subject name violation.
 738
 739 =item B<X509_V_ERR_OCSP_VERIFY_NEEDED>
 740
 741 Returned by the verify callback to indicate an OCSP verification is needed.
 742
 743 =item B<X509_V_ERR_OCSP_VERIFY_FAILED>
 744
 745 Returned by the verify callback to indicate OCSP verification failed.
 746
 747 =item B<X509_V_ERR_OCSP_CERT_UNKNOWN>
 748
 749 Returned by the verify callback to indicate that the certificate is not recognized
 750 by the OCSP responder.
 751
 752 =back
 753
 754 =head1 BUGS
 755
 756 Although the issuer checks are a considerable improvement over the old
 757 technique they still suffer from limitations in the underlying X509_LOOKUP
 758 API. One consequence of this is that trusted certificates with matching
 759 subject name must either appear in a file (as specified by the B<-CAfile>
 760 option) or a directory (as specified by B<-CApath>). If they occur in
 761 both then only the certificates in the file will be recognised.
 762
 763 Previous versions of OpenSSL assume certificates with matching subject
 764 name are identical and mishandled them.
 765
 766 Previous versions of this documentation swapped the meaning of the
 767 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
 768 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
 769
 770 =head1 SEE ALSO
 771
 772 L<openssl(1)>,
 773 L<openssl-x509(1)>
 774
 775 =head1 HISTORY
 776
 777 The B<-show_chain> option was added in OpenSSL 1.1.0.
 778
 779 The B<-issuer_checks> option is deprecated as of OpenSSL 1.1.0 and
 780 is silently ignored.
 781
 782 The B<-sm2-id> and B<-sm2-hex-id> options were added in OpenSSL 3.0.
 783
 784 =head1 COPYRIGHT
 785
 786 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
 787
 788 Licensed under the Apache License 2.0 (the "License").  You may not use
 789 this file except in compliance with the License.  You can obtain a copy
 790 in the file LICENSE in the source distribution or at
 791 L<https://www.openssl.org/source/license.html>.
 792
 793 =cut