5 verify - Utility to verify certificates
12 [B<-CApath directory>]
15 [B<-allow_proxy_certs>]
16 [B<-attime timestamp>]
44 [B<-auth_level level>]
45 [B<-verify_depth num>]
46 [B<-verify_email email>]
47 [B<-verify_hostname hostname>]
49 [B<-verify_name name>]
57 The B<verify> command verifies certificate chains.
65 Print out a usage message.
69 A B<file> of trusted certificates.
70 The file should contain one or more certificates in PEM format.
72 =item B<-CApath directory>
74 A directory of trusted certificates. The certificates should have names
75 of the form: hash.0 or have symbolic links to them of this
76 form ("hash" is the hashed certificate subject name: see the B<-hash> option
77 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
78 create symbolic links to a directory of certificates.
82 Do not load the trusted CA certificates from the default file location.
86 Do not load the trusted CA certificates from the default directory location.
88 =item B<-allow_proxy_certs>
90 Allow the verification of proxy certificates.
92 =item B<-attime timestamp>
94 Perform validation checks using time specified by B<timestamp> and not
95 current system time. B<timestamp> is the number of seconds since
96 01.01.1970 (UNIX time).
98 =item B<-check_ss_sig>
100 Verify the signature on the self-signed root CA. This is disabled by default
101 because it doesn't add any security.
103 =item B<-CRLfile file>
105 The B<file> should contain one or more CRLs in PEM format.
106 This option can be specified more than once to include CRLs from multiple
109 =item B<-crl_download>
111 Attempt to download CRL information for this certificate.
115 Checks end entity certificate validity by attempting to look up a valid CRL.
116 If a valid CRL cannot be found an error occurs.
118 =item B<-crl_check_all>
120 Checks the validity of B<all> certificates in the chain by attempting
121 to look up valid CRLs.
125 Specifying an engine B<id> will cause L<verify(1)> to attempt to load the
127 The engine will then be set as the default for all its supported algorithms.
128 If you want to load certificates or CRLs that require engine support via any of
129 the B<-trusted>, B<-untrusted> or B<-CRLfile> options, the B<-engine> option
130 must be specified before those options.
132 =item B<-explicit_policy>
134 Set policy variable require-explicit-policy (see RFC5280).
136 =item B<-extended_crl>
138 Enable extended CRL features such as indirect CRLs and alternate CRL
141 =item B<-ignore_critical>
143 Normally if an unhandled critical extension is present which is not
144 supported by OpenSSL the certificate is rejected (as required by RFC5280).
145 If this option is set critical extensions are ignored.
147 =item B<-inhibit_any>
149 Set policy variable inhibit-any-policy (see RFC5280).
151 =item B<-inhibit_map>
153 Set policy variable inhibit-policy-mapping (see RFC5280).
155 =item B<-nameopt option>
157 Option which determines how the subject or issuer names are displayed. The
158 B<option> argument can be a single option or multiple options separated by
159 commas. Alternatively the B<-nameopt> switch may be used more than once to
160 set multiple options. See the L<x509(1)> manual page for details.
162 =item B<-no_check_time>
164 This option suppresses checking the validity period of certificates and CRLs
165 against the current time. If option B<-attime timestamp> is used to specify
166 a verification time, the check is not suppressed.
168 =item B<-partial_chain>
170 Allow verification to succeed even if a I<complete> chain cannot be built to a
171 self-signed trust-anchor, provided it is possible to construct a chain to a
172 trusted certificate that might not be self-signed.
176 Enable policy processing and add B<arg> to the user-initial-policy-set (see
177 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
178 This argument can appear more than once.
180 =item B<-policy_check>
182 Enables certificate policy processing.
184 =item B<-policy_print>
186 Print out diagnostics related to policy processing.
188 =item B<-purpose purpose>
190 The intended use for the certificate. If this option is not specified,
191 B<verify> will not consider certificate purpose during chain verification.
192 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
193 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
196 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
198 Enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
199 192 bit, or only 192 bit Level of Security respectively.
200 See RFC6460 for details. In particular the supported signature algorithms are
201 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
204 =item B<-trusted_first>
206 When constructing the certificate chain, use the trusted certificates specified
207 via B<-CAfile>, B<-CApath> or B<-trusted> before any certificates specified via
209 This can be useful in environments with Bridge or Cross-Certified CAs.
210 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
212 =item B<-no_alt_chains>
214 By default, unless B<-trusted_first> is specified, when building a certificate
215 chain, if the first certificate chain found is not trusted, then OpenSSL will
216 attempt to replace untrusted issuer certificates with certificates from the
217 trust store to see if an alternative chain can be found that is trusted.
218 As of OpenSSL 1.1.0, with B<-trusted_first> always on, this option has no
221 =item B<-untrusted file>
223 A B<file> of additional untrusted certificates (intermediate issuer CAs) used
224 to construct a certificate chain from the subject certificate to a trust-anchor.
225 The B<file> should contain one or more certificates in PEM format.
226 This option can be specified more than once to include untrusted certificates
227 from multiple B<files>.
229 =item B<-trusted file>
231 A B<file> of trusted certificates, which must be self-signed, unless the
232 B<-partial_chain> option is specified.
233 The B<file> contains one or more certificates in PEM format.
234 With this option, no additional (e.g., default) certificate lists are
236 That is, the only trust-anchors are those listed in B<file>.
237 This option can be specified more than once to include trusted certificates
238 from multiple B<files>.
239 This option implies the B<-no-CAfile> and B<-no-CApath> options.
240 This option cannot be used in combination with either of the B<-CAfile> or
245 Enable support for delta CRLs.
249 Print extra information about the operations being performed.
251 =item B<-auth_level level>
253 Set the certificate chain authentication security level to B<level>.
254 The authentication security level determines the acceptable signature and
255 public key strength when verifying certificate chains.
256 For a certificate chain to validate, the public keys of all the certificates
257 must meet the specified security B<level>.
258 The signature algorithm security level is enforced for all the certificates in
259 the chain except for the chain's I<trust anchor>, which is either directly
260 trusted or validated by means other than its signature.
261 See L<SSL_CTX_set_security_level(3)> for the definitions of the available
263 The default security level is -1, or "not set".
264 At security level 0 or lower all algorithms are acceptable.
265 Security level 1 requires at least 80-bit-equivalent security and is broadly
266 interoperable, though it will, for example, reject MD5 signatures or RSA keys
267 shorter than 1024 bits.
269 =item B<-verify_depth num>
271 Limit the certificate chain to B<num> intermediate CA certificates.
272 A maximal depth chain can have up to B<num+2> certificates, since neither the
273 end-entity certificate nor the trust-anchor certificate count against the
274 B<-verify_depth> limit.
276 =item B<-verify_email email>
278 Verify if the B<email> matches the email address in Subject Alternative Name or
279 the email in the subject Distinguished Name.
281 =item B<-verify_hostname hostname>
283 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
284 Common Name in the subject certificate.
286 =item B<-verify_ip ip>
288 Verify if the B<ip> matches the IP address in Subject Alternative Name of
289 the subject certificate.
291 =item B<-verify_name name>
293 Use default verification policies like trust model and required certificate
294 policies identified by B<name>.
295 The trust model determines which auxiliary trust or reject OIDs are applicable
296 to verifying the given certificate chain.
297 See the B<-addtrust> and B<-addreject> options of the L<x509(1)> command-line
299 Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
300 B<ssl_client>, B<ssl_server>.
301 These mimics the combinations of purpose and trust settings used in SSL, CMS
303 As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
304 specified, so the B<-verify_name> options are functionally equivalent to the
305 corresponding B<-purpose> settings.
307 =item B<-x509_strict>
309 For strict X.509 compliance, disable non-compliant workarounds for broken
314 Display information about the certificate chain that has been built (if
315 successful). Certificates in the chain that came from the untrusted list will be
316 flagged as "untrusted".
320 Indicates the last option. All arguments following this are assumed to be
321 certificate files. This is useful if the first certificate filename begins
324 =item B<certificates>
326 One or more certificates to verify. If no certificates are given, B<verify>
327 will attempt to read a certificate from standard input. Certificates must be
332 =head1 VERIFY OPERATION
334 The B<verify> program uses the same functions as the internal SSL and S/MIME
335 verification, therefore this description applies to these verify operations
338 There is one crucial difference between the verify operations performed
339 by the B<verify> program: wherever possible an attempt is made to continue
340 after an error whereas normally the verify operation would halt on the
341 first error. This allows all the problems with a certificate chain to be
344 The verify operation consists of a number of separate steps.
346 Firstly a certificate chain is built up starting from the supplied certificate
347 and ending in the root CA.
348 It is an error if the whole chain cannot be built up.
349 The chain is built up by looking up the issuers certificate of the current
351 If a certificate is found which is its own issuer it is assumed to be the root
354 The process of 'looking up the issuers certificate' itself involves a number of
356 After all certificates whose subject name matches the issuer name of the current
357 certificate are subject to further tests.
358 The relevant authority key identifier components of the current certificate (if
359 present) must match the subject key identifier (if present) and issuer and
360 serial number of the candidate issuer, in addition the keyUsage extension of
361 the candidate issuer (if present) must permit certificate signing.
363 The lookup first looks in the list of untrusted certificates and if no match
364 is found the remaining lookups are from the trusted certificates. The root CA
365 is always looked up in the trusted certificate list: if the certificate to
366 verify is a root certificate then an exact match must be found in the trusted
369 The second operation is to check every untrusted certificate's extensions for
370 consistency with the supplied purpose. If the B<-purpose> option is not included
371 then no checks are done. The supplied or "leaf" certificate must have extensions
372 compatible with the supplied purpose and all other certificates must also be valid
373 CA certificates. The precise extensions required are described in more detail in
374 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
376 The third operation is to check the trust settings on the root CA. The root CA
377 should be trusted for the supplied purpose.
378 For compatibility with previous versions of OpenSSL, a certificate with no
379 trust settings is considered to be valid for all purposes.
381 The final operation is to check the validity of the certificate chain. The validity
382 period is checked against the current system time and the notBefore and notAfter
383 dates in the certificate. The certificate signatures are also checked at this
386 If all operations complete successfully then certificate is considered valid. If
387 any operation fails then the certificate is not valid.
391 When a verify operation fails the output messages can be somewhat cryptic. The
392 general form of the error message is:
394 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
395 error 24 at 1 depth lookup:invalid CA certificate
397 The first line contains the name of the certificate being verified followed by
398 the subject name of the certificate. The second line contains the error number
399 and the depth. The depth is number of the certificate being verified when a
400 problem was detected starting with zero for the certificate being verified itself
401 then 1 for the CA that signed the certificate and so on. Finally a text version
402 of the error number is presented.
404 A partial list of the error codes and messages is shown below, this also
405 includes the name of the error code as defined in the header file x509_vfy.h
406 Some of the error codes are defined but never returned: these are described
413 The operation was successful.
415 =item B<X509_V_ERR_UNSPECIFIED>
417 Unspecified error; should not happen.
419 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT>
421 The issuer certificate of a looked up certificate could not be found. This
422 normally means the list of trusted certificates is not complete.
424 =item B<X509_V_ERR_UNABLE_TO_GET_CRL>
426 The CRL of a certificate could not be found.
428 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE>
430 The certificate signature could not be decrypted. This means that the
431 actual signature value could not be determined rather than it not matching
432 the expected value, this is only meaningful for RSA keys.
434 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE>
436 The CRL signature could not be decrypted: this means that the actual
437 signature value could not be determined rather than it not matching the
438 expected value. Unused.
440 =item B<X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY>
442 The public key in the certificate SubjectPublicKeyInfo could not be read.
444 =item B<X509_V_ERR_CERT_SIGNATURE_FAILURE>
446 The signature of the certificate is invalid.
448 =item B<X509_V_ERR_CRL_SIGNATURE_FAILURE>
450 The signature of the certificate is invalid.
452 =item B<X509_V_ERR_CERT_NOT_YET_VALID>
454 The certificate is not yet valid: the notBefore date is after the
457 =item B<X509_V_ERR_CERT_HAS_EXPIRED>
459 The certificate has expired: that is the notAfter date is before the
462 =item B<X509_V_ERR_CRL_NOT_YET_VALID>
464 The CRL is not yet valid.
466 =item B<X509_V_ERR_CRL_HAS_EXPIRED>
470 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD>
472 The certificate notBefore field contains an invalid time.
474 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD>
476 The certificate notAfter field contains an invalid time.
478 =item B<X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD>
480 The CRL lastUpdate field contains an invalid time.
482 =item B<X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD>
484 The CRL nextUpdate field contains an invalid time.
486 =item B<X509_V_ERR_OUT_OF_MEM>
488 An error occurred trying to allocate memory. This should never happen.
490 =item B<X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT>
492 The passed certificate is self-signed and the same certificate cannot
493 be found in the list of trusted certificates.
495 =item B<X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN>
497 The certificate chain could be built up using the untrusted certificates
498 but the root could not be found locally.
500 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY>
502 The issuer certificate could not be found: this occurs if the issuer
503 certificate of an untrusted certificate cannot be found.
505 =item B<X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE>
507 No signatures could be verified because the chain contains only one
508 certificate and it is not self signed.
510 =item B<X509_V_ERR_CERT_CHAIN_TOO_LONG>
512 The certificate chain length is greater than the supplied maximum
515 =item B<X509_V_ERR_CERT_REVOKED>
517 The certificate has been revoked.
519 =item B<X509_V_ERR_INVALID_CA>
521 A CA certificate is invalid. Either it is not a CA or its extensions
522 are not consistent with the supplied purpose.
524 =item B<X509_V_ERR_PATH_LENGTH_EXCEEDED>
526 The basicConstraints pathlength parameter has been exceeded.
528 =item B<X509_V_ERR_INVALID_PURPOSE>
530 The supplied certificate cannot be used for the specified purpose.
532 =item B<X509_V_ERR_CERT_UNTRUSTED>
534 The root CA is not marked as trusted for the specified purpose.
536 =item B<X509_V_ERR_CERT_REJECTED>
538 The root CA is marked to reject the specified purpose.
540 =item B<X509_V_ERR_SUBJECT_ISSUER_MISMATCH>
542 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
543 B<-issuer_checks> option.
545 =item B<X509_V_ERR_AKID_SKID_MISMATCH>
547 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
548 B<-issuer_checks> option.
550 =item B<X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH>
552 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
553 B<-issuer_checks> option.
555 =item B<X509_V_ERR_KEYUSAGE_NO_CERTSIGN>
557 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
558 B<-issuer_checks> option.
560 =item B<X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER>
562 Unable to get CRL issuer certificate.
564 =item B<X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION>
566 Unhandled critical extension.
568 =item B<X509_V_ERR_KEYUSAGE_NO_CRL_SIGN>
570 Key usage does not include CRL signing.
572 =item B<X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION>
574 Unhandled critical CRL extension.
576 =item B<X509_V_ERR_INVALID_NON_CA>
578 Invalid non-CA certificate has CA markings.
580 =item B<X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED>
582 Proxy path length constraint exceeded.
584 =item B<X509_V_ERR_PROXY_SUBJECT_INVALID>
586 Proxy certificate subject is invalid. It MUST be the same as the issuer
587 with a single CN component added.
589 =item B<X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE>
591 Key usage does not include digital signature.
593 =item B<X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED>
595 Proxy certificates not allowed, please use B<-allow_proxy_certs>.
597 =item B<X509_V_ERR_INVALID_EXTENSION>
599 Invalid or inconsistent certificate extension.
601 =item B<X509_V_ERR_INVALID_POLICY_EXTENSION>
603 Invalid or inconsistent certificate policy extension.
605 =item B<X509_V_ERR_NO_EXPLICIT_POLICY>
609 =item B<X509_V_ERR_DIFFERENT_CRL_SCOPE>
613 =item B<X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE>
615 Unsupported extension feature.
617 =item B<X509_V_ERR_UNNESTED_RESOURCE>
619 RFC 3779 resource not subset of parent's resources.
621 =item B<X509_V_ERR_PERMITTED_VIOLATION>
623 Permitted subtree violation.
625 =item B<X509_V_ERR_EXCLUDED_VIOLATION>
627 Excluded subtree violation.
629 =item B<X509_V_ERR_SUBTREE_MINMAX>
631 Name constraints minimum and maximum not supported.
633 =item B<X509_V_ERR_APPLICATION_VERIFICATION>
635 Application verification failure. Unused.
637 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE>
639 Unsupported name constraint type.
641 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX>
643 Unsupported or invalid name constraint syntax.
645 =item B<X509_V_ERR_UNSUPPORTED_NAME_SYNTAX>
647 Unsupported or invalid name syntax.
649 =item B<X509_V_ERR_CRL_PATH_VALIDATION_ERROR>
651 CRL path validation error.
653 =item B<X509_V_ERR_PATH_LOOP>
657 =item B<X509_V_ERR_SUITE_B_INVALID_VERSION>
659 Suite B: certificate version invalid.
661 =item B<X509_V_ERR_SUITE_B_INVALID_ALGORITHM>
663 Suite B: invalid public key algorithm.
665 =item B<X509_V_ERR_SUITE_B_INVALID_CURVE>
667 Suite B: invalid ECC curve.
669 =item B<X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM>
671 Suite B: invalid signature algorithm.
673 =item B<X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED>
675 Suite B: curve not allowed for this LOS.
677 =item B<X509_V_ERR_SUITE_B_CANNOT_SIGN_P_384_WITH_P_256>
679 Suite B: cannot sign P-384 with P-256.
681 =item B<X509_V_ERR_HOSTNAME_MISMATCH>
685 =item B<X509_V_ERR_EMAIL_MISMATCH>
687 Email address mismatch.
689 =item B<X509_V_ERR_IP_ADDRESS_MISMATCH>
693 =item B<X509_V_ERR_DANE_NO_MATCH>
695 DANE TLSA authentication is enabled, but no TLSA records matched the
697 This error is only possible in L<s_client(1)>.
699 =item B<X509_V_ERR_EE_KEY_TOO_SMALL>
701 EE certificate key too weak.
703 =item B<X509_ERR_CA_KEY_TOO_SMALL>
705 CA certificate key too weak.
707 =item B<X509_ERR_CA_MD_TOO_WEAK>
709 CA signature digest algorithm too weak.
711 =item B<X509_V_ERR_INVALID_CALL>
713 nvalid certificate verification context.
715 =item B<X509_V_ERR_STORE_LOOKUP>
717 Issuer certificate lookup error.
719 =item B<X509_V_ERR_NO_VALID_SCTS>
721 Certificate Transparency required, but no valid SCTs found.
723 =item B<X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION>
725 Proxy subject name violation.
727 =item B<X509_V_ERR_OCSP_VERIFY_NEEDED>
729 Returned by the verify callback to indicate an OCSP verification is needed.
731 =item B<X509_V_ERR_OCSP_VERIFY_FAILED>
733 Returned by the verify callback to indicate OCSP verification failed.
735 =item B<X509_V_ERR_OCSP_CERT_UNKNOWN>
737 Returned by the verify callback to indicate that the certificate is not recognized
738 by the OCSP responder.
744 Although the issuer checks are a considerable improvement over the old
745 technique they still suffer from limitations in the underlying X509_LOOKUP
746 API. One consequence of this is that trusted certificates with matching
747 subject name must either appear in a file (as specified by the B<-CAfile>
748 option) or a directory (as specified by B<-CApath>). If they occur in
749 both then only the certificates in the file will be recognised.
751 Previous versions of OpenSSL assume certificates with matching subject
752 name are identical and mishandled them.
754 Previous versions of this documentation swapped the meaning of the
755 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
756 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
764 The B<-show_chain> option was first added to OpenSSL 1.1.0.
766 The B<-issuer_checks> option is deprecated as of OpenSSL 1.1.0 and
771 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
773 Licensed under the OpenSSL license (the "License"). You may not use
774 this file except in compliance with the License. You can obtain a copy
775 in the file LICENSE in the source distribution or at
776 L<https://www.openssl.org/source/license.html>.