5 openssl-verify - Utility to verify certificates
12 [B<-CApath> I<directory>]
15 [B<-allow_proxy_certs>]
16 [B<-attime> I<timestamp>]
28 [B<-nameopt> I<option>]
34 [B<-purpose> I<purpose>]
40 [B<-untrusted> I<file>]
44 [B<-auth_level> I<level>]
45 [B<-verify_depth> I<num>]
46 [B<-verify_email> I<email>]
47 [B<-verify_hostname> I<hostname>]
49 [B<-verify_name> I<name>]
52 [B<-sm2-id> I<string>]
53 [B<-sm2-hex-id> I<hex-string>]
57 =for comment ifdef engine sm2-id sm2-hex-id
61 The B<verify> command verifies certificate chains.
69 Print out a usage message.
71 =item B<-CAfile> I<file>
73 A I<file> of trusted certificates.
74 The file should contain one or more certificates in PEM format.
76 =item B<-CApath> I<directory>
78 A directory of trusted certificates. The certificates should have names
79 of the form: F<I<hash>.0> or have symbolic links to them of this
80 form (I<hash> is the hashed certificate subject name: see the B<-hash> option
81 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
82 create symbolic links to a directory of certificates.
86 Do not load the trusted CA certificates from the default file location.
90 Do not load the trusted CA certificates from the default directory location.
92 =item B<-allow_proxy_certs>
94 Allow the verification of proxy certificates.
96 =item B<-attime> I<timestamp>
98 Perform validation checks using time specified by I<timestamp> and not
99 current system time. I<timestamp> is the number of seconds since
100 01.01.1970 (UNIX time).
102 =item B<-check_ss_sig>
104 Verify the signature on the self-signed root CA. This is disabled by default
105 because it doesn't add any security.
107 =item B<-CRLfile> I<file>
109 The I<file> should contain one or more CRLs in PEM format.
110 This option can be specified more than once to include CRLs from multiple
113 =item B<-crl_download>
115 Attempt to download CRL information for this certificate.
119 Checks end entity certificate validity by attempting to look up a valid CRL.
120 If a valid CRL cannot be found an error occurs.
122 =item B<-crl_check_all>
124 Checks the validity of B<all> certificates in the chain by attempting
125 to look up valid CRLs.
127 =item B<-engine> I<id>
129 Specifying an engine I<id> will cause L<verify(1)> to attempt to load the
131 The engine will then be set as the default for all its supported algorithms.
132 If you want to load certificates or CRLs that require engine support via any of
133 the B<-trusted>, B<-untrusted> or B<-CRLfile> options, the B<-engine> option
134 must be specified before those options.
136 =item B<-explicit_policy>
138 Set policy variable require-explicit-policy (see RFC5280).
140 =item B<-extended_crl>
142 Enable extended CRL features such as indirect CRLs and alternate CRL
145 =item B<-ignore_critical>
147 Normally if an unhandled critical extension is present which is not
148 supported by OpenSSL the certificate is rejected (as required by RFC5280).
149 If this option is set critical extensions are ignored.
151 =item B<-inhibit_any>
153 Set policy variable inhibit-any-policy (see RFC5280).
155 =item B<-inhibit_map>
157 Set policy variable inhibit-policy-mapping (see RFC5280).
159 =item B<-nameopt> I<option>
161 Option which determines how the subject or issuer names are displayed. The
162 I<option> argument can be a single option or multiple options separated by
163 commas. Alternatively the B<-nameopt> switch may be used more than once to
164 set multiple options. See the L<x509(1)> manual page for details.
166 =item B<-no_check_time>
168 This option suppresses checking the validity period of certificates and CRLs
169 against the current time. If option B<-attime> is used to specify
170 a verification time, the check is not suppressed.
172 =item B<-partial_chain>
174 Allow verification to succeed even if a I<complete> chain cannot be built to a
175 self-signed trust-anchor, provided it is possible to construct a chain to a
176 trusted certificate that might not be self-signed.
178 =item B<-policy> I<arg>
180 Enable policy processing and add I<arg> to the user-initial-policy-set (see
181 RFC5280). The policy I<arg> can be an object name an OID in numeric form.
182 This argument can appear more than once.
184 =item B<-policy_check>
186 Enables certificate policy processing.
188 =item B<-policy_print>
190 Print out diagnostics related to policy processing.
192 =item B<-purpose> I<purpose>
194 The intended use for the certificate. If this option is not specified,
195 B<verify> will not consider certificate purpose during chain verification.
196 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
197 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
200 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
202 Enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
203 192 bit, or only 192 bit Level of Security respectively.
204 See RFC6460 for details. In particular the supported signature algorithms are
205 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
208 =item B<-trusted_first>
210 When constructing the certificate chain, use the trusted certificates specified
211 via B<-CAfile>, B<-CApath> or B<-trusted> before any certificates specified via
213 This can be useful in environments with Bridge or Cross-Certified CAs.
214 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
216 =item B<-no_alt_chains>
218 By default, unless B<-trusted_first> is specified, when building a certificate
219 chain, if the first certificate chain found is not trusted, then OpenSSL will
220 attempt to replace untrusted issuer certificates with certificates from the
221 trust store to see if an alternative chain can be found that is trusted.
222 As of OpenSSL 1.1.0, with B<-trusted_first> always on, this option has no
225 =item B<-untrusted> I<file>
227 A I<file> of additional untrusted certificates (intermediate issuer CAs) used
228 to construct a certificate chain from the subject certificate to a trust-anchor.
229 The I<file> should contain one or more certificates in PEM format.
230 This option can be specified more than once to include untrusted certificates
231 from multiple I<file>s.
233 =item B<-trusted> I<file>
235 A I<file> of trusted certificates, which must be self-signed, unless the
236 B<-partial_chain> option is specified.
237 The I<file> contains one or more certificates in PEM format.
238 With this option, no additional (e.g., default) certificate lists are
240 That is, the only trust-anchors are those listed in I<file>.
241 This option can be specified more than once to include trusted certificates
242 from multiple I<file>s.
243 This option implies the B<-no-CAfile> and B<-no-CApath> options.
244 This option cannot be used in combination with either of the B<-CAfile> or
249 Enable support for delta CRLs.
253 Print extra information about the operations being performed.
255 =item B<-auth_level> I<level>
257 Set the certificate chain authentication security level to I<level>.
258 The authentication security level determines the acceptable signature and
259 public key strength when verifying certificate chains.
260 For a certificate chain to validate, the public keys of all the certificates
261 must meet the specified security I<level>.
262 The signature algorithm security level is enforced for all the certificates in
263 the chain except for the chain's I<trust anchor>, which is either directly
264 trusted or validated by means other than its signature.
265 See L<SSL_CTX_set_security_level(3)> for the definitions of the available
267 The default security level is -1, or "not set".
268 At security level 0 or lower all algorithms are acceptable.
269 Security level 1 requires at least 80-bit-equivalent security and is broadly
270 interoperable, though it will, for example, reject MD5 signatures or RSA keys
271 shorter than 1024 bits.
273 =item B<-verify_depth> I<num>
275 Limit the certificate chain to I<num> intermediate CA certificates.
276 A maximal depth chain can have up to I<num>+2 certificates, since neither the
277 end-entity certificate nor the trust-anchor certificate count against the
278 B<-verify_depth> limit.
280 =item B<-verify_email> I<email>
282 Verify if I<email> matches the email address in Subject Alternative Name or
283 the email in the subject Distinguished Name.
285 =item B<-verify_hostname> I<hostname>
287 Verify if I<hostname> matches DNS name in Subject Alternative Name or
288 Common Name in the subject certificate.
290 =item B<-verify_ip> I<ip>
292 Verify if I<ip> matches the IP address in Subject Alternative Name of
293 the subject certificate.
295 =item B<-verify_name> I<name>
297 Use default verification policies like trust model and required certificate
298 policies identified by I<name>.
299 The trust model determines which auxiliary trust or reject OIDs are applicable
300 to verifying the given certificate chain.
301 See the B<-addtrust> and B<-addreject> options of the L<x509(1)> command-line
303 Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
304 B<ssl_client>, B<ssl_server>.
305 These mimics the combinations of purpose and trust settings used in SSL, CMS
307 As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
308 specified, so the B<-verify_name> options are functionally equivalent to the
309 corresponding B<-purpose> settings.
311 =item B<-x509_strict>
313 For strict X.509 compliance, disable non-compliant workarounds for broken
318 Display information about the certificate chain that has been built (if
319 successful). Certificates in the chain that came from the untrusted list will be
320 flagged as "untrusted".
324 Specify the ID string to use when verifying an SM2 certificate. The ID string is
325 required by the SM2 signature algorithm for signing and verification.
329 Specify a binary ID string to use when signing or verifying using an SM2
330 certificate. The argument for this option is string of hexadecimal digits.
334 Indicates the last option. All arguments following this are assumed to be
335 certificate files. This is useful if the first certificate filename begins
338 =item I<certificate> ...
340 One or more certificates to verify. If no certificates are given, B<verify>
341 will attempt to read a certificate from standard input. Certificates must be
346 =head1 VERIFY OPERATION
348 The B<verify> program uses the same functions as the internal SSL and S/MIME
349 verification, therefore this description applies to these verify operations
352 There is one crucial difference between the verify operations performed
353 by the B<verify> program: wherever possible an attempt is made to continue
354 after an error whereas normally the verify operation would halt on the
355 first error. This allows all the problems with a certificate chain to be
358 The verify operation consists of a number of separate steps.
360 Firstly a certificate chain is built up starting from the supplied certificate
361 and ending in the root CA.
362 It is an error if the whole chain cannot be built up.
363 The chain is built up by looking up the issuers certificate of the current
365 If a certificate is found which is its own issuer it is assumed to be the root
368 The process of 'looking up the issuers certificate' itself involves a number of
370 After all certificates whose subject name matches the issuer name of the current
371 certificate are subject to further tests.
372 The relevant authority key identifier components of the current certificate (if
373 present) must match the subject key identifier (if present) and issuer and
374 serial number of the candidate issuer, in addition the keyUsage extension of
375 the candidate issuer (if present) must permit certificate signing.
377 The lookup first looks in the list of untrusted certificates and if no match
378 is found the remaining lookups are from the trusted certificates. The root CA
379 is always looked up in the trusted certificate list: if the certificate to
380 verify is a root certificate then an exact match must be found in the trusted
383 The second operation is to check every untrusted certificate's extensions for
384 consistency with the supplied purpose. If the B<-purpose> option is not included
385 then no checks are done. The supplied or "leaf" certificate must have extensions
386 compatible with the supplied purpose and all other certificates must also be valid
387 CA certificates. The precise extensions required are described in more detail in
388 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
390 The third operation is to check the trust settings on the root CA. The root CA
391 should be trusted for the supplied purpose.
392 For compatibility with previous versions of OpenSSL, a certificate with no
393 trust settings is considered to be valid for all purposes.
395 The final operation is to check the validity of the certificate chain. The validity
396 period is checked against the current system time and the notBefore and notAfter
397 dates in the certificate. The certificate signatures are also checked at this
400 If all operations complete successfully then certificate is considered valid. If
401 any operation fails then the certificate is not valid.
405 When a verify operation fails the output messages can be somewhat cryptic. The
406 general form of the error message is:
408 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
409 error 24 at 1 depth lookup:invalid CA certificate
411 The first line contains the name of the certificate being verified followed by
412 the subject name of the certificate. The second line contains the error number
413 and the depth. The depth is number of the certificate being verified when a
414 problem was detected starting with zero for the certificate being verified itself
415 then 1 for the CA that signed the certificate and so on. Finally a text version
416 of the error number is presented.
418 A partial list of the error codes and messages is shown below, this also
419 includes the name of the error code as defined in the header file x509_vfy.h
420 Some of the error codes are defined but never returned: these are described
427 The operation was successful.
429 =item B<X509_V_ERR_UNSPECIFIED>
431 Unspecified error; should not happen.
433 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT>
435 The issuer certificate of a looked up certificate could not be found. This
436 normally means the list of trusted certificates is not complete.
438 =item B<X509_V_ERR_UNABLE_TO_GET_CRL>
440 The CRL of a certificate could not be found.
442 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE>
444 The certificate signature could not be decrypted. This means that the
445 actual signature value could not be determined rather than it not matching
446 the expected value, this is only meaningful for RSA keys.
448 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE>
450 The CRL signature could not be decrypted: this means that the actual
451 signature value could not be determined rather than it not matching the
452 expected value. Unused.
454 =item B<X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY>
456 The public key in the certificate SubjectPublicKeyInfo could not be read.
458 =item B<X509_V_ERR_CERT_SIGNATURE_FAILURE>
460 The signature of the certificate is invalid.
462 =item B<X509_V_ERR_CRL_SIGNATURE_FAILURE>
464 The signature of the certificate is invalid.
466 =item B<X509_V_ERR_CERT_NOT_YET_VALID>
468 The certificate is not yet valid: the notBefore date is after the
471 =item B<X509_V_ERR_CERT_HAS_EXPIRED>
473 The certificate has expired: that is the notAfter date is before the
476 =item B<X509_V_ERR_CRL_NOT_YET_VALID>
478 The CRL is not yet valid.
480 =item B<X509_V_ERR_CRL_HAS_EXPIRED>
484 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD>
486 The certificate notBefore field contains an invalid time.
488 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD>
490 The certificate notAfter field contains an invalid time.
492 =item B<X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD>
494 The CRL lastUpdate field contains an invalid time.
496 =item B<X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD>
498 The CRL nextUpdate field contains an invalid time.
500 =item B<X509_V_ERR_OUT_OF_MEM>
502 An error occurred trying to allocate memory. This should never happen.
504 =item B<X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT>
506 The passed certificate is self-signed and the same certificate cannot
507 be found in the list of trusted certificates.
509 =item B<X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN>
511 The certificate chain could be built up using the untrusted certificates
512 but the root could not be found locally.
514 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY>
516 The issuer certificate could not be found: this occurs if the issuer
517 certificate of an untrusted certificate cannot be found.
519 =item B<X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE>
521 No signatures could be verified because the chain contains only one
522 certificate and it is not self signed.
524 =item B<X509_V_ERR_CERT_CHAIN_TOO_LONG>
526 The certificate chain length is greater than the supplied maximum
529 =item B<X509_V_ERR_CERT_REVOKED>
531 The certificate has been revoked.
533 =item B<X509_V_ERR_INVALID_CA>
535 A CA certificate is invalid. Either it is not a CA or its extensions
536 are not consistent with the supplied purpose.
538 =item B<X509_V_ERR_PATH_LENGTH_EXCEEDED>
540 The basicConstraints pathlength parameter has been exceeded.
542 =item B<X509_V_ERR_INVALID_PURPOSE>
544 The supplied certificate cannot be used for the specified purpose.
546 =item B<X509_V_ERR_CERT_UNTRUSTED>
548 The root CA is not marked as trusted for the specified purpose.
550 =item B<X509_V_ERR_CERT_REJECTED>
552 The root CA is marked to reject the specified purpose.
554 =item B<X509_V_ERR_SUBJECT_ISSUER_MISMATCH>
556 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
557 B<-issuer_checks> option.
559 =item B<X509_V_ERR_AKID_SKID_MISMATCH>
561 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
562 B<-issuer_checks> option.
564 =item B<X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH>
566 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
567 B<-issuer_checks> option.
569 =item B<X509_V_ERR_KEYUSAGE_NO_CERTSIGN>
571 Not used as of OpenSSL 1.1.0 as a result of the deprecation of the
572 B<-issuer_checks> option.
574 =item B<X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER>
576 Unable to get CRL issuer certificate.
578 =item B<X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION>
580 Unhandled critical extension.
582 =item B<X509_V_ERR_KEYUSAGE_NO_CRL_SIGN>
584 Key usage does not include CRL signing.
586 =item B<X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION>
588 Unhandled critical CRL extension.
590 =item B<X509_V_ERR_INVALID_NON_CA>
592 Invalid non-CA certificate has CA markings.
594 =item B<X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED>
596 Proxy path length constraint exceeded.
598 =item B<X509_V_ERR_PROXY_SUBJECT_INVALID>
600 Proxy certificate subject is invalid. It MUST be the same as the issuer
601 with a single CN component added.
603 =item B<X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE>
605 Key usage does not include digital signature.
607 =item B<X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED>
609 Proxy certificates not allowed, please use B<-allow_proxy_certs>.
611 =item B<X509_V_ERR_INVALID_EXTENSION>
613 Invalid or inconsistent certificate extension.
615 =item B<X509_V_ERR_INVALID_POLICY_EXTENSION>
617 Invalid or inconsistent certificate policy extension.
619 =item B<X509_V_ERR_NO_EXPLICIT_POLICY>
623 =item B<X509_V_ERR_DIFFERENT_CRL_SCOPE>
627 =item B<X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE>
629 Unsupported extension feature.
631 =item B<X509_V_ERR_UNNESTED_RESOURCE>
633 RFC 3779 resource not subset of parent's resources.
635 =item B<X509_V_ERR_PERMITTED_VIOLATION>
637 Permitted subtree violation.
639 =item B<X509_V_ERR_EXCLUDED_VIOLATION>
641 Excluded subtree violation.
643 =item B<X509_V_ERR_SUBTREE_MINMAX>
645 Name constraints minimum and maximum not supported.
647 =item B<X509_V_ERR_APPLICATION_VERIFICATION>
649 Application verification failure. Unused.
651 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE>
653 Unsupported name constraint type.
655 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX>
657 Unsupported or invalid name constraint syntax.
659 =item B<X509_V_ERR_UNSUPPORTED_NAME_SYNTAX>
661 Unsupported or invalid name syntax.
663 =item B<X509_V_ERR_CRL_PATH_VALIDATION_ERROR>
665 CRL path validation error.
667 =item B<X509_V_ERR_PATH_LOOP>
671 =item B<X509_V_ERR_SUITE_B_INVALID_VERSION>
673 Suite B: certificate version invalid.
675 =item B<X509_V_ERR_SUITE_B_INVALID_ALGORITHM>
677 Suite B: invalid public key algorithm.
679 =item B<X509_V_ERR_SUITE_B_INVALID_CURVE>
681 Suite B: invalid ECC curve.
683 =item B<X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM>
685 Suite B: invalid signature algorithm.
687 =item B<X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED>
689 Suite B: curve not allowed for this LOS.
691 =item B<X509_V_ERR_SUITE_B_CANNOT_SIGN_P_384_WITH_P_256>
693 Suite B: cannot sign P-384 with P-256.
695 =item B<X509_V_ERR_HOSTNAME_MISMATCH>
699 =item B<X509_V_ERR_EMAIL_MISMATCH>
701 Email address mismatch.
703 =item B<X509_V_ERR_IP_ADDRESS_MISMATCH>
707 =item B<X509_V_ERR_DANE_NO_MATCH>
709 DANE TLSA authentication is enabled, but no TLSA records matched the
711 This error is only possible in L<s_client(1)>.
713 =item B<X509_V_ERR_EE_KEY_TOO_SMALL>
715 EE certificate key too weak.
717 =item B<X509_ERR_CA_KEY_TOO_SMALL>
719 CA certificate key too weak.
721 =item B<X509_ERR_CA_MD_TOO_WEAK>
723 CA signature digest algorithm too weak.
725 =item B<X509_V_ERR_INVALID_CALL>
727 nvalid certificate verification context.
729 =item B<X509_V_ERR_STORE_LOOKUP>
731 Issuer certificate lookup error.
733 =item B<X509_V_ERR_NO_VALID_SCTS>
735 Certificate Transparency required, but no valid SCTs found.
737 =item B<X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION>
739 Proxy subject name violation.
741 =item B<X509_V_ERR_OCSP_VERIFY_NEEDED>
743 Returned by the verify callback to indicate an OCSP verification is needed.
745 =item B<X509_V_ERR_OCSP_VERIFY_FAILED>
747 Returned by the verify callback to indicate OCSP verification failed.
749 =item B<X509_V_ERR_OCSP_CERT_UNKNOWN>
751 Returned by the verify callback to indicate that the certificate is not recognized
752 by the OCSP responder.
758 Although the issuer checks are a considerable improvement over the old
759 technique they still suffer from limitations in the underlying X509_LOOKUP
760 API. One consequence of this is that trusted certificates with matching
761 subject name must either appear in a file (as specified by the B<-CAfile>
762 option) or a directory (as specified by B<-CApath>). If they occur in
763 both then only the certificates in the file will be recognised.
765 Previous versions of OpenSSL assume certificates with matching subject
766 name are identical and mishandled them.
768 Previous versions of this documentation swapped the meaning of the
769 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
770 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
779 The B<-show_chain> option was added in OpenSSL 1.1.0.
781 The B<-issuer_checks> option is deprecated as of OpenSSL 1.1.0 and
784 The B<-sm2-id> and B<-sm2-hex-id> options were added in OpenSSL 3.0.
788 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
790 Licensed under the Apache License 2.0 (the "License"). You may not use
791 this file except in compliance with the License. You can obtain a copy
792 in the file LICENSE in the source distribution or at
793 L<https://www.openssl.org/source/license.html>.