5 verify - Utility to verify certificates
12 [B<-CApath directory>]
15 [B<-allow_proxy_certs>]
16 [B<-attime timestamp>]
43 [B<-auth_level level>]
44 [B<-verify_depth num>]
45 [B<-verify_email email>]
46 [B<-verify_hostname hostname>]
48 [B<-verify_name name>]
56 The B<verify> command verifies certificate chains.
64 Print out a usage message.
68 A B<file> of trusted certificates.
69 The file should contain one or more certificates in PEM format.
71 =item B<-CApath directory>
73 A directory of trusted certificates. The certificates should have names
74 of the form: hash.0 or have symbolic links to them of this
75 form ("hash" is the hashed certificate subject name: see the B<-hash> option
76 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
77 create symbolic links to a directory of certificates.
81 Do not load the trusted CA certificates from the default file location
85 Do not load the trusted CA certificates from the default directory location
87 =item B<-allow_proxy_certs>
89 Allow the verification of proxy certificates
91 =item B<-attime timestamp>
93 Perform validation checks using time specified by B<timestamp> and not
94 current system time. B<timestamp> is the number of seconds since
95 01.01.1970 (UNIX time).
97 =item B<-check_ss_sig>
99 Verify the signature on the self-signed root CA. This is disabled by default
100 because it doesn't add any security.
102 =item B<-CRLfile file>
104 The B<file> should contain one or more CRLs in PEM format.
105 This option can be specified more than once to include CRLs from multiple
108 =item B<-crl_download>
110 Attempt to download CRL information for this certificate.
114 Checks end entity certificate validity by attempting to look up a valid CRL.
115 If a valid CRL cannot be found an error occurs.
117 =item B<-crl_check_all>
119 Checks the validity of B<all> certificates in the chain by attempting
120 to look up valid CRLs.
124 Specifying an engine B<id> will cause L<verify(1)> to attempt to load the
126 The engine will then be set as the default for all its supported algorithms.
127 If you want to load certificates or CRLs that require engine support via any of
128 the B<-trusted>, B<-untrusted> or B<-CRLfile> options, the B<-engine> option
129 must be specified before those options.
131 =item B<-explicit_policy>
133 Set policy variable require-explicit-policy (see RFC5280).
135 =item B<-extended_crl>
137 Enable extended CRL features such as indirect CRLs and alternate CRL
140 =item B<-ignore_critical>
142 Normally if an unhandled critical extension is present which is not
143 supported by OpenSSL the certificate is rejected (as required by RFC5280).
144 If this option is set critical extensions are ignored.
146 =item B<-inhibit_any>
148 Set policy variable inhibit-any-policy (see RFC5280).
150 =item B<-inhibit_map>
152 Set policy variable inhibit-policy-mapping (see RFC5280).
154 =item B<-no_check_time>
156 This option suppresses checking the validity period of certificates and CRLs
157 against the current time. If option B<-attime timestamp> is used to specify
158 a verification time, the check is not suppressed.
160 =item B<-partial_chain>
162 Allow verification to succeed even if a I<complete> chain cannot be built to a
163 self-signed trust-anchor, provided it is possible to construct a chain to a
164 trusted certificate that might not be self-signed.
168 Enable policy processing and add B<arg> to the user-initial-policy-set (see
169 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
170 This argument can appear more than once.
172 =item B<-policy_check>
174 Enables certificate policy processing.
176 =item B<-policy_print>
178 Print out diagnostics related to policy processing.
180 =item B<-purpose purpose>
182 The intended use for the certificate. If this option is not specified,
183 B<verify> will not consider certificate purpose during chain verification.
184 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
185 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
188 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
190 enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
191 192 bit, or only 192 bit Level of Security respectively.
192 See RFC6460 for details. In particular the supported signature algorithms are
193 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
196 =item B<-trusted_first>
198 When constructing the certificate chain, use the trusted certificates specified
199 via B<-CAfile>, B<-CApath> or B<-trusted> before any certificates specified via
201 This can be useful in environments with Bridge or Cross-Certified CAs.
202 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
204 =item B<-no_alt_chains>
206 By default, unless B<-trusted_first> is specified, when building a certificate
207 chain, if the first certificate chain found is not trusted, then OpenSSL will
208 attempt to replace untrusted issuer certificates with certificates from the
209 trust store to see if an alternative chain can be found that is trusted.
210 As of OpenSSL 1.1.0, with B<-trusted_first> always on, this option has no
213 =item B<-untrusted file>
215 A B<file> of additional untrusted certificates (intermediate issuer CAs) used
216 to construct a certificate chain from the subject certificate to a trust-anchor.
217 The B<file> should contain one or more certificates in PEM format.
218 This option can be specified more than once to include untrusted certificates
219 from multiple B<files>.
221 =item B<-trusted file>
223 A B<file> of trusted certificates, which must be self-signed, unless the
224 B<-partial_chain> option is specified.
225 The B<file> contains one or more certificates in PEM format.
226 With this option, no additional (e.g., default) certificate lists are
228 That is, the only trust-anchors are those listed in B<file>.
229 This option can be specified more than once to include trusted certificates
230 from multiple B<files>.
231 This option implies the B<-no-CAfile> and B<-no-CApath> options.
232 This option cannot be used in combination with either of the B<-CAfile> or
237 Enable support for delta CRLs.
241 Print extra information about the operations being performed.
243 =item B<-auth_level level>
245 Set the certificate chain authentication security level to B<level>.
246 The authentication security level determines the acceptable signature and
247 public key strength when verifying certificate chains.
248 For a certificate chain to validate, the public keys of all the certificates
249 must meet the specified security B<level>.
250 The signature algorithm security level is enforced for all the certificates in
251 the chain except for the chain's I<trust anchor>, which is either directly
252 trusted or validated by means other than its signature.
253 See L<SSL_CTX_set_security_level(3)> for the definitions of the available
255 The default security level is -1, or "not set".
256 At security level 0 or lower all algorithms are acceptable.
257 Security level 1 requires at least 80-bit-equivalent security and is broadly
258 interoperable, though it will, for example, reject MD5 signatures or RSA keys
259 shorter than 1024 bits.
261 =item B<-verify_depth num>
263 Limit the certificate chain to B<num> intermediate CA certificates.
264 A maximal depth chain can have up to B<num+2> certificates, since neither the
265 end-entity certificate nor the trust-anchor certificate count against the
266 B<-verify_depth> limit.
268 =item B<-verify_email email>
270 Verify if the B<email> matches the email address in Subject Alternative Name or
271 the email in the subject Distinguished Name.
273 =item B<-verify_hostname hostname>
275 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
276 Common Name in the subject certificate.
278 =item B<-verify_ip ip>
280 Verify if the B<ip> matches the IP address in Subject Alternative Name of
281 the subject certificate.
283 =item B<-verify_name name>
285 Use default verification policies like trust model and required certificate
286 policies identified by B<name>.
287 The trust model determines which auxiliary trust or reject OIDs are applicable
288 to verifying the given certificate chain.
289 See the B<-addtrust> and B<-addreject> options of the L<x509(1)> command-line
291 Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
292 B<ssl_client>, B<ssl_server>.
293 These mimics the combinations of purpose and trust settings used in SSL, CMS
295 As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
296 specified, so the B<-verify_name> options are functionally equivalent to the
297 corresponding B<-purpose> settings.
299 =item B<-x509_strict>
301 For strict X.509 compliance, disable non-compliant workarounds for broken
306 Display information about the certificate chain that has been built (if
307 successful). Certificates in the chain that came from the untrusted list will be
308 flagged as "untrusted".
312 Indicates the last option. All arguments following this are assumed to be
313 certificate files. This is useful if the first certificate filename begins
316 =item B<certificates>
318 One or more certificates to verify. If no certificates are given, B<verify>
319 will attempt to read a certificate from standard input. Certificates must be
324 =head1 VERIFY OPERATION
326 The B<verify> program uses the same functions as the internal SSL and S/MIME
327 verification, therefore this description applies to these verify operations
330 There is one crucial difference between the verify operations performed
331 by the B<verify> program: wherever possible an attempt is made to continue
332 after an error whereas normally the verify operation would halt on the
333 first error. This allows all the problems with a certificate chain to be
336 The verify operation consists of a number of separate steps.
338 Firstly a certificate chain is built up starting from the supplied certificate
339 and ending in the root CA.
340 It is an error if the whole chain cannot be built up.
341 The chain is built up by looking up the issuers certificate of the current
343 If a certificate is found which is its own issuer it is assumed to be the root
346 The process of 'looking up the issuers certificate' itself involves a number of
348 After all certificates whose subject name matches the issuer name of the current
349 certificate are subject to further tests.
350 The relevant authority key identifier components of the current certificate (if
351 present) must match the subject key identifier (if present) and issuer and
352 serial number of the candidate issuer, in addition the keyUsage extension of
353 the candidate issuer (if present) must permit certificate signing.
355 The lookup first looks in the list of untrusted certificates and if no match
356 is found the remaining lookups are from the trusted certificates. The root CA
357 is always looked up in the trusted certificate list: if the certificate to
358 verify is a root certificate then an exact match must be found in the trusted
361 The second operation is to check every untrusted certificate's extensions for
362 consistency with the supplied purpose. If the B<-purpose> option is not included
363 then no checks are done. The supplied or "leaf" certificate must have extensions
364 compatible with the supplied purpose and all other certificates must also be valid
365 CA certificates. The precise extensions required are described in more detail in
366 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
368 The third operation is to check the trust settings on the root CA. The root CA
369 should be trusted for the supplied purpose.
370 For compatibility with previous versions of OpenSSL, a certificate with no
371 trust settings is considered to be valid for all purposes.
373 The final operation is to check the validity of the certificate chain. The validity
374 period is checked against the current system time and the notBefore and notAfter
375 dates in the certificate. The certificate signatures are also checked at this
378 If all operations complete successfully then certificate is considered valid. If
379 any operation fails then the certificate is not valid.
383 When a verify operation fails the output messages can be somewhat cryptic. The
384 general form of the error message is:
386 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
387 error 24 at 1 depth lookup:invalid CA certificate
389 The first line contains the name of the certificate being verified followed by
390 the subject name of the certificate. The second line contains the error number
391 and the depth. The depth is number of the certificate being verified when a
392 problem was detected starting with zero for the certificate being verified itself
393 then 1 for the CA that signed the certificate and so on. Finally a text version
394 of the error number is presented.
396 A partial list of the error codes and messages is shown below, this also
397 includes the name of the error code as defined in the header file x509_vfy.h
398 Some of the error codes are defined but never returned: these are described
405 The operation was successful.
407 =item B<X509_V_ERR_UNSPECIFIED>
409 Unspecified error; should not happen.
411 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT>
413 The issuer certificate of a looked up certificate could not be found. This
414 normally means the list of trusted certificates is not complete.
416 =item B<X509_V_ERR_UNABLE_TO_GET_CRL>
418 The CRL of a certificate could not be found.
420 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE>
422 The certificate signature could not be decrypted. This means that the actual signature value
423 could not be determined rather than it not matching the expected value, this is only
424 meaningful for RSA keys.
426 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE>
428 The CRL signature could not be decrypted: this means that the actual signature value
429 could not be determined rather than it not matching the expected value. Unused.
431 =item B<X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY>
433 The public key in the certificate SubjectPublicKeyInfo could not be read.
435 =item B<X509_V_ERR_CERT_SIGNATURE_FAILURE>
437 The signature of the certificate is invalid.
439 =item B<X509_V_ERR_CRL_SIGNATURE_FAILURE>
441 The signature of the certificate is invalid.
443 =item B<X509_V_ERR_CERT_NOT_YET_VALID>
445 The certificate is not yet valid: the notBefore date is after the current time.
447 =item B<X509_V_ERR_CERT_HAS_EXPIRED>
449 The certificate has expired: that is the notAfter date is before the current time.
451 =item B<X509_V_ERR_CRL_NOT_YET_VALID>
453 The CRL is not yet valid.
455 =item B<X509_V_ERR_CRL_HAS_EXPIRED>
459 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD>
461 The certificate notBefore field contains an invalid time.
463 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD>
465 The certificate notAfter field contains an invalid time.
467 =item B<X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD>
469 The CRL lastUpdate field contains an invalid time.
471 =item B<X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD>
473 The CRL nextUpdate field contains an invalid time.
475 =item B<X509_V_ERR_OUT_OF_MEM>
477 An error occurred trying to allocate memory. This should never happen.
479 =item B<X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT>
481 The passed certificate is self-signed and the same certificate cannot be found in the list of
482 trusted certificates.
484 =item B<X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN>
486 The certificate chain could be built up using the untrusted certificates but the root could not
489 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY>
491 The issuer certificate could not be found: this occurs if the issuer
492 certificate of an untrusted certificate cannot be found.
494 =item B<X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE>
496 No signatures could be verified because the chain contains only one certificate and it is not
499 =item B<X509_V_ERR_CERT_CHAIN_TOO_LONG>
501 The certificate chain length is greater than the supplied maximum depth. Unused.
503 =item B<X509_V_ERR_CERT_REVOKED>
505 The certificate has been revoked.
507 =item B<X509_V_ERR_INVALID_CA>
509 A CA certificate is invalid. Either it is not a CA or its extensions are not consistent
510 with the supplied purpose.
512 =item B<X509_V_ERR_PATH_LENGTH_EXCEEDED>
514 The basicConstraints pathlength parameter has been exceeded.
516 =item B<X509_V_ERR_INVALID_PURPOSE>
518 The supplied certificate cannot be used for the specified purpose.
520 =item B<X509_V_ERR_CERT_UNTRUSTED>
522 the root CA is not marked as trusted for the specified purpose.
524 =item B<X509_V_ERR_CERT_REJECTED>
526 The root CA is marked to reject the specified purpose.
528 =item B<X509_V_ERR_SUBJECT_ISSUER_MISMATCH>
530 not used as of OpenSSL 1.1.0 as a result of the deprecation of the
531 B<-issuer_checks> option.
533 =item B<X509_V_ERR_AKID_SKID_MISMATCH>
535 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
536 B<-issuer_checks> option.
538 =item B<X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH>
540 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
541 B<-issuer_checks> option.
543 =item B<X509_V_ERR_KEYUSAGE_NO_CERTSIGN>
545 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
546 B<-issuer_checks> option.
548 =item B<X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER>
550 Unable to get CRL issuer certificate.
552 =item B<X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION>
554 Unhandled critical extension.
556 =item B<X509_V_ERR_KEYUSAGE_NO_CRL_SIGN>
558 Key usage does not include CRL signing.
560 =item B<X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION>
562 Unhandled critical CRL extension.
564 =item B<X509_V_ERR_INVALID_NON_CA>
566 Invalid non-CA certificate has CA markings.
568 =item B<X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED>
570 Proxy path length constraint exceeded.
572 =item B<X509_V_ERR_PROXY_SUBJECT_INVALID>
574 Proxy certificate subject is invalid. It MUST be the same as the issuer
575 with a single CN component added.
577 =item B<X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE>
579 Key usage does not include digital signature.
581 =item B<X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED>
583 Proxy certificates not allowed, please use B<-allow_proxy_certs>.
585 =item B<X509_V_ERR_INVALID_EXTENSION>
587 Invalid or inconsistent certificate extension.
589 =item B<X509_V_ERR_INVALID_POLICY_EXTENSION>
591 Invalid or inconsistent certificate policy extension.
593 =item B<X509_V_ERR_NO_EXPLICIT_POLICY>
597 =item B<X509_V_ERR_DIFFERENT_CRL_SCOPE>
601 =item B<X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE>
603 Unsupported extension feature.
605 =item B<X509_V_ERR_UNNESTED_RESOURCE>
607 RFC 3779 resource not subset of parent's resources.
609 =item B<X509_V_ERR_PERMITTED_VIOLATION>
611 Permitted subtree violation.
613 =item B<X509_V_ERR_EXCLUDED_VIOLATION>
615 Excluded subtree violation.
617 =item B<X509_V_ERR_SUBTREE_MINMAX>
619 Name constraints minimum and maximum not supported.
621 =item B<X509_V_ERR_APPLICATION_VERIFICATION>
623 Application verification failure. Unused.
625 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE>
627 Unsupported name constraint type.
629 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX>
631 Unsupported or invalid name constraint syntax.
633 =item B<X509_V_ERR_UNSUPPORTED_NAME_SYNTAX>
635 Unsupported or invalid name syntax.
637 =item B<X509_V_ERR_CRL_PATH_VALIDATION_ERROR>
639 CRL path validation error.
641 =item B<X509_V_ERR_PATH_LOOP>
645 =item B<X509_V_ERR_SUITE_B_INVALID_VERSION>
647 Suite B: certificate version invalid.
649 =item B<X509_V_ERR_SUITE_B_INVALID_ALGORITHM>
651 Suite B: invalid public key algorithm.
653 =item B<X509_V_ERR_SUITE_B_INVALID_CURVE>
655 Suite B: invalid ECC curve.
657 =item B<X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM>
659 Suite B: invalid signature algorithm.
661 =item B<X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED>
663 Suite B: curve not allowed for this LOS.
665 =item B<X509_V_ERR_SUITE_B_CANNOT_SIGN_P_384_WITH_P_256>
667 Suite B: cannot sign P-384 with P-256.
669 =item B<X509_V_ERR_HOSTNAME_MISMATCH>
673 =item B<X509_V_ERR_EMAIL_MISMATCH>
675 Email address mismatch.
677 =item B<X509_V_ERR_IP_ADDRESS_MISMATCH>
681 =item B<X509_V_ERR_DANE_NO_MATCH>
683 DANE TLSA authentication is enabled, but no TLSA records matched the
685 This error is only possible in L<s_client(1)>.
691 Although the issuer checks are a considerable improvement over the old technique they still
692 suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that
693 trusted certificates with matching subject name must either appear in a file (as specified by the
694 B<-CAfile> option) or a directory (as specified by B<-CApath>). If they occur in both then only
695 the certificates in the file will be recognised.
697 Previous versions of OpenSSL assume certificates with matching subject name are identical and
700 Previous versions of this documentation swapped the meaning of the
701 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
702 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
710 The B<-show_chain> option was first added to OpenSSL 1.1.0.
712 The B<-issuer_checks> option is deprecated as of OpenSSL 1.1.0 and
717 Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
719 Licensed under the OpenSSL license (the "License"). You may not use
720 this file except in compliance with the License. You can obtain a copy
721 in the file LICENSE in the source distribution or at
722 L<https://www.openssl.org/source/license.html>.