6 verify - Utility to verify certificates
13 [B<-CApath directory>]
16 [B<-allow_proxy_certs>]
17 [B<-attime timestamp>]
45 [B<-auth_level level>]
46 [B<-verify_depth num>]
47 [B<-verify_email email>]
48 [B<-verify_hostname hostname>]
50 [B<-verify_name name>]
54 [B<-sm2-hex-id hex-string>]
60 The B<verify> command verifies certificate chains.
68 Print out a usage message.
72 A B<file> of trusted certificates.
73 The file should contain one or more certificates in PEM format.
75 =item B<-CApath directory>
77 A directory of trusted certificates. The certificates should have names
78 of the form: hash.0 or have symbolic links to them of this
79 form ("hash" is the hashed certificate subject name: see the B<-hash> option
80 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
81 create symbolic links to a directory of certificates.
85 Do not load the trusted CA certificates from the default file location.
89 Do not load the trusted CA certificates from the default directory location.
91 =item B<-allow_proxy_certs>
93 Allow the verification of proxy certificates.
95 =item B<-attime timestamp>
97 Perform validation checks using time specified by B<timestamp> and not
98 current system time. B<timestamp> is the number of seconds since
99 01.01.1970 (UNIX time).
101 =item B<-check_ss_sig>
103 Verify the signature on the self-signed root CA. This is disabled by default
104 because it doesn't add any security.
106 =item B<-CRLfile file>
108 The B<file> should contain one or more CRLs in PEM format.
109 This option can be specified more than once to include CRLs from multiple
112 =item B<-crl_download>
114 Attempt to download CRL information for this certificate.
118 Checks end entity certificate validity by attempting to look up a valid CRL.
119 If a valid CRL cannot be found an error occurs.
121 =item B<-crl_check_all>
123 Checks the validity of B<all> certificates in the chain by attempting
124 to look up valid CRLs.
128 Specifying an engine B<id> will cause L<verify(1)> to attempt to load the
130 The engine will then be set as the default for all its supported algorithms.
131 If you want to load certificates or CRLs that require engine support via any of
132 the B<-trusted>, B<-untrusted> or B<-CRLfile> options, the B<-engine> option
133 must be specified before those options.
135 =item B<-explicit_policy>
137 Set policy variable require-explicit-policy (see RFC5280).
139 =item B<-extended_crl>
141 Enable extended CRL features such as indirect CRLs and alternate CRL
144 =item B<-ignore_critical>
146 Normally if an unhandled critical extension is present which is not
147 supported by OpenSSL the certificate is rejected (as required by RFC5280).
148 If this option is set critical extensions are ignored.
150 =item B<-inhibit_any>
152 Set policy variable inhibit-any-policy (see RFC5280).
154 =item B<-inhibit_map>
156 Set policy variable inhibit-policy-mapping (see RFC5280).
158 =item B<-nameopt option>
160 Option which determines how the subject or issuer names are displayed. The
161 B<option> argument can be a single option or multiple options separated by
162 commas. Alternatively the B<-nameopt> switch may be used more than once to
163 set multiple options. See the L<x509(1)> manual page for details.
165 =item B<-no_check_time>
167 This option suppresses checking the validity period of certificates and CRLs
168 against the current time. If option B<-attime timestamp> is used to specify
169 a verification time, the check is not suppressed.
171 =item B<-partial_chain>
173 Allow verification to succeed even if a I<complete> chain cannot be built to a
174 self-signed trust-anchor, provided it is possible to construct a chain to a
175 trusted certificate that might not be self-signed.
179 Enable policy processing and add B<arg> to the user-initial-policy-set (see
180 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
181 This argument can appear more than once.
183 =item B<-policy_check>
185 Enables certificate policy processing.
187 =item B<-policy_print>
189 Print out diagnostics related to policy processing.
191 =item B<-purpose purpose>
193 The intended use for the certificate. If this option is not specified,
194 B<verify> will not consider certificate purpose during chain verification.
195 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
196 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
199 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
201 Enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
202 192 bit, or only 192 bit Level of Security respectively.
203 See RFC6460 for details. In particular the supported signature algorithms are
204 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
207 =item B<-trusted_first>
209 When constructing the certificate chain, use the trusted certificates specified
210 via B<-CAfile>, B<-CApath> or B<-trusted> before any certificates specified via
212 This can be useful in environments with Bridge or Cross-Certified CAs.
213 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
215 =item B<-no_alt_chains>
217 By default, unless B<-trusted_first> is specified, when building a certificate
218 chain, if the first certificate chain found is not trusted, then OpenSSL will
219 attempt to replace untrusted issuer certificates with certificates from the
220 trust store to see if an alternative chain can be found that is trusted.
221 As of OpenSSL 1.1.0, with B<-trusted_first> always on, this option has no
224 =item B<-untrusted file>
226 A B<file> of additional untrusted certificates (intermediate issuer CAs) used
227 to construct a certificate chain from the subject certificate to a trust-anchor.
228 The B<file> should contain one or more certificates in PEM format.
229 This option can be specified more than once to include untrusted certificates
230 from multiple B<files>.
232 =item B<-trusted file>
234 A B<file> of trusted certificates, which must be self-signed, unless the
235 B<-partial_chain> option is specified.
236 The B<file> contains one or more certificates in PEM format.
237 With this option, no additional (e.g., default) certificate lists are
239 That is, the only trust-anchors are those listed in B<file>.
240 This option can be specified more than once to include trusted certificates
241 from multiple B<files>.
242 This option implies the B<-no-CAfile> and B<-no-CApath> options.
243 This option cannot be used in combination with either of the B<-CAfile> or
248 Enable support for delta CRLs.
252 Print extra information about the operations being performed.
254 =item B<-auth_level level>
256 Set the certificate chain authentication security level to B<level>.
257 The authentication security level determines the acceptable signature and
258 public key strength when verifying certificate chains.
259 For a certificate chain to validate, the public keys of all the certificates
260 must meet the specified security B<level>.
261 The signature algorithm security level is enforced for all the certificates in
262 the chain except for the chain's I<trust anchor>, which is either directly
263 trusted or validated by means other than its signature.
264 See L<SSL_CTX_set_security_level(3)> for the definitions of the available
266 The default security level is -1, or "not set".
267 At security level 0 or lower all algorithms are acceptable.
268 Security level 1 requires at least 80-bit-equivalent security and is broadly
269 interoperable, though it will, for example, reject MD5 signatures or RSA keys
270 shorter than 1024 bits.
272 =item B<-verify_depth num>
274 Limit the certificate chain to B<num> intermediate CA certificates.
275 A maximal depth chain can have up to B<num+2> certificates, since neither the
276 end-entity certificate nor the trust-anchor certificate count against the
277 B<-verify_depth> limit.
279 =item B<-verify_email email>
281 Verify if the B<email> matches the email address in Subject Alternative Name or
282 the email in the subject Distinguished Name.
284 =item B<-verify_hostname hostname>
286 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
287 Common Name in the subject certificate.
289 =item B<-verify_ip ip>
291 Verify if the B<ip> matches the IP address in Subject Alternative Name of
292 the subject certificate.
294 =item B<-verify_name name>
296 Use default verification policies like trust model and required certificate
297 policies identified by B<name>.
298 The trust model determines which auxiliary trust or reject OIDs are applicable
299 to verifying the given certificate chain.
300 See the B<-addtrust> and B<-addreject> options of the L<x509(1)> command-line
302 Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
303 B<ssl_client>, B<ssl_server>.
304 These mimics the combinations of purpose and trust settings used in SSL, CMS
306 As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
307 specified, so the B<-verify_name> options are functionally equivalent to the
308 corresponding B<-purpose> settings.
310 =item B<-x509_strict>
312 For strict X.509 compliance, disable non-compliant workarounds for broken
317 Display information about the certificate chain that has been built (if
318 successful). Certificates in the chain that came from the untrusted list will be
319 flagged as "untrusted".
323 Specify the ID string to use when verifying an SM2 certificate. The ID string is
324 required by the SM2 signature algorithm for signing and verification.
328 Specify a binary ID string to use when signing or verifying using an SM2
329 certificate. The argument for this option is string of hexadecimal digits.
333 Indicates the last option. All arguments following this are assumed to be
334 certificate files. This is useful if the first certificate filename begins
337 =item B<certificates>
339 One or more certificates to verify. If no certificates are given, B<verify>
340 will attempt to read a certificate from standard input. Certificates must be
345 =head1 VERIFY OPERATION
347 The B<verify> program uses the same functions as the internal SSL and S/MIME
348 verification, therefore this description applies to these verify operations
351 There is one crucial difference between the verify operations performed
352 by the B<verify> program: wherever possible an attempt is made to continue
353 after an error whereas normally the verify operation would halt on the
354 first error. This allows all the problems with a certificate chain to be
357 The verify operation consists of a number of separate steps.
359 Firstly a certificate chain is built up starting from the supplied certificate
360 and ending in the root CA.
361 It is an error if the whole chain cannot be built up.
362 The chain is built up by looking up the issuers certificate of the current
364 If a certificate is found which is its own issuer it is assumed to be the root
367 The process of 'looking up the issuers certificate' itself involves a number of
369 After all certificates whose subject name matches the issuer name of the current
370 certificate are subject to further tests.
371 The relevant authority key identifier components of the current certificate (if
372 present) must match the subject key identifier (if present) and issuer and
373 serial number of the candidate issuer, in addition the keyUsage extension of
374 the candidate issuer (if present) must permit certificate signing.
376 The lookup first looks in the list of untrusted certificates and if no match
377 is found the remaining lookups are from the trusted certificates. The root CA
378 is always looked up in the trusted certificate list: if the certificate to
379 verify is a root certificate then an exact match must be found in the trusted
382 The second operation is to check every untrusted certificate's extensions for
383 consistency with the supplied purpose. If the B<-purpose> option is not included
384 then no checks are done. The supplied or "leaf" certificate must have extensions
385 compatible with the supplied purpose and all other certificates must also be valid
386 CA certificates. The precise extensions required are described in more detail in
387 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
389 The third operation is to check the trust settings on the root CA. The root CA
390 should be trusted for the supplied purpose.
391 For compatibility with previous versions of OpenSSL, a certificate with no
392 trust settings is considered to be valid for all purposes.
394 The final operation is to check the validity of the certificate chain. The validity
395 period is checked against the current system time and the notBefore and notAfter
396 dates in the certificate. The certificate signatures are also checked at this
399 If all operations complete successfully then certificate is considered valid. If
400 any operation fails then the certificate is not valid.
404 When a verify operation fails the output messages can be somewhat cryptic. The
405 general form of the error message is:
407 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
408 error 24 at 1 depth lookup:invalid CA certificate
410 The first line contains the name of the certificate being verified followed by
411 the subject name of the certificate. The second line contains the error number
412 and the depth. The depth is number of the certificate being verified when a
413 problem was detected starting with zero for the certificate being verified itself
414 then 1 for the CA that signed the certificate and so on. Finally a text version
415 of the error number is presented.
417 A partial list of the error codes and messages is shown below, this also
418 includes the name of the error code as defined in the header file x509_vfy.h
419 Some of the error codes are defined but never returned: these are described
426 The operation was successful.
428 =item B<X509_V_ERR_UNSPECIFIED>
430 Unspecified error; should not happen.
432 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT>
434 The issuer certificate of a looked up certificate could not be found. This
435 normally means the list of trusted certificates is not complete.
437 =item B<X509_V_ERR_UNABLE_TO_GET_CRL>
439 The CRL of a certificate could not be found.
441 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE>
443 The certificate signature could not be decrypted. This means that the
444 actual signature value could not be determined rather than it not matching
445 the expected value, this is only meaningful for RSA keys.
447 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE>
449 The CRL signature could not be decrypted: this means that the actual
450 signature value could not be determined rather than it not matching the
451 expected value. Unused.
453 =item B<X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY>
455 The public key in the certificate SubjectPublicKeyInfo could not be read.
457 =item B<X509_V_ERR_CERT_SIGNATURE_FAILURE>
459 The signature of the certificate is invalid.
461 =item B<X509_V_ERR_CRL_SIGNATURE_FAILURE>
463 The signature of the certificate is invalid.
465 =item B<X509_V_ERR_CERT_NOT_YET_VALID>
467 The certificate is not yet valid: the notBefore date is after the
470 =item B<X509_V_ERR_CERT_HAS_EXPIRED>
472 The certificate has expired: that is the notAfter date is before the
475 =item B<X509_V_ERR_CRL_NOT_YET_VALID>
477 The CRL is not yet valid.
479 =item B<X509_V_ERR_CRL_HAS_EXPIRED>
483 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD>
485 The certificate notBefore field contains an invalid time.
487 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD>
489 The certificate notAfter field contains an invalid time.
491 =item B<X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD>
493 The CRL lastUpdate field contains an invalid time.
495 =item B<X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD>
497 The CRL nextUpdate field contains an invalid time.
499 =item B<X509_V_ERR_OUT_OF_MEM>
501 An error occurred trying to allocate memory. This should never happen.
503 =item B<X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT>
505 The passed certificate is self-signed and the same certificate cannot
506 be found in the list of trusted certificates.
508 =item B<X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN>
510 The certificate chain could be built up using the untrusted certificates
511 but the root could not be found locally.
513 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY>
515 The issuer certificate could not be found: this occurs if the issuer
516 certificate of an untrusted certificate cannot be found.
518 =item B<X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE>
520 No signatures could be verified because the chain contains only one
521 certificate and it is not self signed.
523 =item B<X509_V_ERR_CERT_CHAIN_TOO_LONG>
525 The certificate chain length is greater than the supplied maximum
528 =item B<X509_V_ERR_CERT_REVOKED>
530 The certificate has been revoked.
532 =item B<X509_V_ERR_INVALID_CA>
534 A CA certificate is invalid. Either it is not a CA or its extensions
535 are not consistent with the supplied purpose.
537 =item B<X509_V_ERR_PATH_LENGTH_EXCEEDED>
539 The basicConstraints pathlength parameter has been exceeded.
541 =item B<X509_V_ERR_INVALID_PURPOSE>
543 The supplied certificate cannot be used for the specified purpose.
545 =item B<X509_V_ERR_CERT_UNTRUSTED>
547 The root CA is not marked as trusted for the specified purpose.
549 =item B<X509_V_ERR_CERT_REJECTED>
551 The root CA is marked to reject the specified purpose.
553 =item B<X509_V_ERR_SUBJECT_ISSUER_MISMATCH>
555 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
556 B<-issuer_checks> option.
558 =item B<X509_V_ERR_AKID_SKID_MISMATCH>
560 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
561 B<-issuer_checks> option.
563 =item B<X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH>
565 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
566 B<-issuer_checks> option.
568 =item B<X509_V_ERR_KEYUSAGE_NO_CERTSIGN>
570 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
571 B<-issuer_checks> option.
573 =item B<X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER>
575 Unable to get CRL issuer certificate.
577 =item B<X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION>
579 Unhandled critical extension.
581 =item B<X509_V_ERR_KEYUSAGE_NO_CRL_SIGN>
583 Key usage does not include CRL signing.
585 =item B<X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION>
587 Unhandled critical CRL extension.
589 =item B<X509_V_ERR_INVALID_NON_CA>
591 Invalid non-CA certificate has CA markings.
593 =item B<X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED>
595 Proxy path length constraint exceeded.
597 =item B<X509_V_ERR_PROXY_SUBJECT_INVALID>
599 Proxy certificate subject is invalid. It MUST be the same as the issuer
600 with a single CN component added.
602 =item B<X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE>
604 Key usage does not include digital signature.
606 =item B<X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED>
608 Proxy certificates not allowed, please use B<-allow_proxy_certs>.
610 =item B<X509_V_ERR_INVALID_EXTENSION>
612 Invalid or inconsistent certificate extension.
614 =item B<X509_V_ERR_INVALID_POLICY_EXTENSION>
616 Invalid or inconsistent certificate policy extension.
618 =item B<X509_V_ERR_NO_EXPLICIT_POLICY>
622 =item B<X509_V_ERR_DIFFERENT_CRL_SCOPE>
626 =item B<X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE>
628 Unsupported extension feature.
630 =item B<X509_V_ERR_UNNESTED_RESOURCE>
632 RFC 3779 resource not subset of parent's resources.
634 =item B<X509_V_ERR_PERMITTED_VIOLATION>
636 Permitted subtree violation.
638 =item B<X509_V_ERR_EXCLUDED_VIOLATION>
640 Excluded subtree violation.
642 =item B<X509_V_ERR_SUBTREE_MINMAX>
644 Name constraints minimum and maximum not supported.
646 =item B<X509_V_ERR_APPLICATION_VERIFICATION>
648 Application verification failure. Unused.
650 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE>
652 Unsupported name constraint type.
654 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX>
656 Unsupported or invalid name constraint syntax.
658 =item B<X509_V_ERR_UNSUPPORTED_NAME_SYNTAX>
660 Unsupported or invalid name syntax.
662 =item B<X509_V_ERR_CRL_PATH_VALIDATION_ERROR>
664 CRL path validation error.
666 =item B<X509_V_ERR_PATH_LOOP>
670 =item B<X509_V_ERR_SUITE_B_INVALID_VERSION>
672 Suite B: certificate version invalid.
674 =item B<X509_V_ERR_SUITE_B_INVALID_ALGORITHM>
676 Suite B: invalid public key algorithm.
678 =item B<X509_V_ERR_SUITE_B_INVALID_CURVE>
680 Suite B: invalid ECC curve.
682 =item B<X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM>
684 Suite B: invalid signature algorithm.
686 =item B<X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED>
688 Suite B: curve not allowed for this LOS.
690 =item B<X509_V_ERR_SUITE_B_CANNOT_SIGN_P_384_WITH_P_256>
692 Suite B: cannot sign P-384 with P-256.
694 =item B<X509_V_ERR_HOSTNAME_MISMATCH>
698 =item B<X509_V_ERR_EMAIL_MISMATCH>
700 Email address mismatch.
702 =item B<X509_V_ERR_IP_ADDRESS_MISMATCH>
706 =item B<X509_V_ERR_DANE_NO_MATCH>
708 DANE TLSA authentication is enabled, but no TLSA records matched the
710 This error is only possible in L<s_client(1)>.
712 =item B<X509_V_ERR_EE_KEY_TOO_SMALL>
714 EE certificate key too weak.
716 =item B<X509_ERR_CA_KEY_TOO_SMALL>
718 CA certificate key too weak.
720 =item B<X509_ERR_CA_MD_TOO_WEAK>
722 CA signature digest algorithm too weak.
724 =item B<X509_V_ERR_INVALID_CALL>
726 nvalid certificate verification context.
728 =item B<X509_V_ERR_STORE_LOOKUP>
730 Issuer certificate lookup error.
732 =item B<X509_V_ERR_NO_VALID_SCTS>
734 Certificate Transparency required, but no valid SCTs found.
736 =item B<X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION>
738 Proxy subject name violation.
740 =item B<X509_V_ERR_OCSP_VERIFY_NEEDED>
742 Returned by the verify callback to indicate an OCSP verification is needed.
744 =item B<X509_V_ERR_OCSP_VERIFY_FAILED>
746 Returned by the verify callback to indicate OCSP verification failed.
748 =item B<X509_V_ERR_OCSP_CERT_UNKNOWN>
750 Returned by the verify callback to indicate that the certificate is not recognized
751 by the OCSP responder.
757 Although the issuer checks are a considerable improvement over the old
758 technique they still suffer from limitations in the underlying X509_LOOKUP
759 API. One consequence of this is that trusted certificates with matching
760 subject name must either appear in a file (as specified by the B<-CAfile>
761 option) or a directory (as specified by B<-CApath>). If they occur in
762 both then only the certificates in the file will be recognised.
764 Previous versions of OpenSSL assume certificates with matching subject
765 name are identical and mishandled them.
767 Previous versions of this documentation swapped the meaning of the
768 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
769 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
777 The B<-show_chain> option was added in OpenSSL 1.1.0.
779 The B<-issuer_checks> option is deprecated as of OpenSSL 1.1.0 and
782 The B<-sm2-id> and B<-sm2-hex-id> options were added in OpenSSL 3.0.
786 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
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>.