5 verify - Utility to verify certificates
12 [B<-CApath directory>]
15 [B<-attime timestamp>]
42 [B<-auth_level level>]
43 [B<-verify_depth num>]
44 [B<-verify_email email>]
45 [B<-verify_hostname hostname>]
47 [B<-verify_name name>]
55 The B<verify> command verifies certificate chains.
57 =head1 COMMAND OPTIONS
63 Print out a usage message.
67 A B<file> of trusted certificates.
68 The file should contain one or more certificates in PEM format.
70 =item B<-CApath directory>
72 A directory of trusted certificates. The certificates should have names
73 of the form: hash.0 or have symbolic links to them of this
74 form ("hash" is the hashed certificate subject name: see the B<-hash> option
75 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
76 create symbolic links to a directory of certificates.
80 Do not load the trusted CA certificates from the default file location
84 Do not load the trusted CA certificates from the default directory location
86 =item B<-attime timestamp>
88 Perform validation checks using time specified by B<timestamp> and not
89 current system time. B<timestamp> is the number of seconds since
90 01.01.1970 (UNIX time).
92 =item B<-check_ss_sig>
94 Verify the signature on the self-signed root CA. This is disabled by default
95 because it doesn't add any security.
97 =item B<-CRLfile file>
99 The B<file> should contain one or more CRLs in PEM format.
100 This option can be specified more than once to include CRLs from multiple
103 =item B<-crl_download>
105 Attempt to download CRL information for this certificate.
109 Checks end entity certificate validity by attempting to look up a valid CRL.
110 If a valid CRL cannot be found an error occurs.
112 =item B<-crl_check_all>
114 Checks the validity of B<all> certificates in the chain by attempting
115 to look up valid CRLs.
119 Specifying an engine B<id> will cause L<verify(1)> to attempt to load the
121 The engine will then be set as the default for all its supported algorithms.
122 If you want to load certificates or CRLs that require engine support via any of
123 the B<-trusted>, B<-untrusted> or B<-CRLfile> options, the B<-engine> option
124 must be specified before those options.
126 =item B<-explicit_policy>
128 Set policy variable require-explicit-policy (see RFC5280).
130 =item B<-extended_crl>
132 Enable extended CRL features such as indirect CRLs and alternate CRL
135 =item B<-ignore_critical>
137 Normally if an unhandled critical extension is present which is not
138 supported by OpenSSL the certificate is rejected (as required by RFC5280).
139 If this option is set critical extensions are ignored.
141 =item B<-inhibit_any>
143 Set policy variable inhibit-any-policy (see RFC5280).
145 =item B<-inhibit_map>
147 Set policy variable inhibit-policy-mapping (see RFC5280).
149 =item B<-no_check_time>
151 This option suppresses checking the validity period of certificates and CRLs
152 against the current time. If option B<-attime timestamp> is used to specify
153 a verification time, the check is not suppressed.
155 =item B<-partial_chain>
157 Allow verification to succeed even if a I<complete> chain cannot be built to a
158 self-signed trust-anchor, provided it is possible to construct a chain to a
159 trusted certificate that might not be self-signed.
163 Enable policy processing and add B<arg> to the user-initial-policy-set (see
164 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
165 This argument can appear more than once.
167 =item B<-policy_check>
169 Enables certificate policy processing.
171 =item B<-policy_print>
173 Print out diagnostics related to policy processing.
175 =item B<-purpose purpose>
177 The intended use for the certificate. If this option is not specified,
178 B<verify> will not consider certificate purpose during chain verification.
179 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
180 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
183 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
185 enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
186 192 bit, or only 192 bit Level of Security respectively.
187 See RFC6460 for details. In particular the supported signature algorithms are
188 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
191 =item B<-trusted_first>
193 When constructing the certificate chain, use the trusted certificates specified
194 via B<-CAfile>, B<-CApath> or B<-trusted> before any certificates specified via
196 This can be useful in environments with Bridge or Cross-Certified CAs.
197 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
199 =item B<-no_alt_chains>
201 By default, unless B<-trusted_first> is specified, when building a certificate
202 chain, if the first certificate chain found is not trusted, then OpenSSL will
203 attempt to replace untrusted issuer certificates with certificates from the
204 trust store to see if an alternative chain can be found that is trusted.
205 As of OpenSSL 1.1.0, with B<-trusted_first> always on, this option has no
208 =item B<-untrusted file>
210 A B<file> of additional untrusted certificates (intermediate issuer CAs) used
211 to construct a certificate chain from the subject certificate to a trust-anchor.
212 The B<file> should contain one or more certificates in PEM format.
213 This option can be specified more than once to include untrusted certificates
214 from multiple B<files>.
216 =item B<-trusted file>
218 A B<file> of trusted certificates, which must be self-signed, unless the
219 B<-partial_chain> option is specified.
220 The B<file> contains one or more certificates in PEM format.
221 With this option, no additional (e.g., default) certificate lists are
223 That is, the only trust-anchors are those listed in B<file>.
224 This option can be specified more than once to include trusted certificates
225 from multiple B<files>.
226 This option implies the B<-no-CAfile> and B<-no-CApath> options.
227 This option cannot be used in combination with either of the B<-CAfile> or
232 Enable support for delta CRLs.
236 Print extra information about the operations being performed.
238 =item B<-auth_level level>
240 Set the certificate chain authentication security level to B<level>.
241 The authentication security level determines the acceptable signature and
242 public key strength when verifying certificate chains.
243 For a certificate chain to validate, the public keys of all the certificates
244 must meet the specified security B<level>.
245 The signature algorithm security level is enforced for all the certificates in
246 the chain except for the chain's I<trust anchor>, which is either directly
247 trusted or validated by means other than its signature.
248 See L<SSL_CTX_set_security_level(3)> for the definitions of the available
250 The default security level is -1, or "not set".
251 At security level 0 or lower all algorithms are acceptable.
252 Security level 1 requires at least 80-bit-equivalent security and is broadly
253 interoperable, though it will, for example, reject MD5 signatures or RSA keys
254 shorter than 1024 bits.
256 =item B<-verify_depth num>
258 Limit the certificate chain to B<num> intermediate CA certificates.
259 A maximal depth chain can have up to B<num+2> certificates, since neither the
260 end-entity certificate nor the trust-anchor certificate count against the
261 B<-verify_depth> limit.
263 =item B<-verify_email email>
265 Verify if the B<email> matches the email address in Subject Alternative Name or
266 the email in the subject Distinguished Name.
268 =item B<-verify_hostname hostname>
270 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
271 Common Name in the subject certificate.
273 =item B<-verify_ip ip>
275 Verify if the B<ip> matches the IP address in Subject Alternative Name of
276 the subject certificate.
278 =item B<-verify_name name>
280 Use default verification policies like trust model and required certificate
281 policies identified by B<name>.
282 The trust model determines which auxiliary trust or reject OIDs are applicable
283 to verifying the given certificate chain.
284 See the B<-addtrust> and B<-addreject> options of the L<x509(1)> command-line
286 Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
287 B<ssl_client>, B<ssl_server>.
288 These mimics the combinations of purpose and trust settings used in SSL, CMS
290 As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
291 specified, so the B<-verify_name> options are functionally equivalent to the
292 corresponding B<-purpose> settings.
294 =item B<-x509_strict>
296 For strict X.509 compliance, disable non-compliant workarounds for broken
301 Display information about the certificate chain that has been built (if
302 successful). Certificates in the chain that came from the untrusted list will be
303 flagged as "untrusted".
307 Indicates the last option. All arguments following this are assumed to be
308 certificate files. This is useful if the first certificate filename begins
311 =item B<certificates>
313 One or more certificates to verify. If no certificates are given, B<verify>
314 will attempt to read a certificate from standard input. Certificates must be
319 =head1 VERIFY OPERATION
321 The B<verify> program uses the same functions as the internal SSL and S/MIME
322 verification, therefore this description applies to these verify operations
325 There is one crucial difference between the verify operations performed
326 by the B<verify> program: wherever possible an attempt is made to continue
327 after an error whereas normally the verify operation would halt on the
328 first error. This allows all the problems with a certificate chain to be
331 The verify operation consists of a number of separate steps.
333 Firstly a certificate chain is built up starting from the supplied certificate
334 and ending in the root CA.
335 It is an error if the whole chain cannot be built up.
336 The chain is built up by looking up the issuers certificate of the current
338 If a certificate is found which is its own issuer it is assumed to be the root
341 The process of 'looking up the issuers certificate' itself involves a number of
343 After all certificates whose subject name matches the issuer name of the current
344 certificate are subject to further tests.
345 The relevant authority key identifier components of the current certificate (if
346 present) must match the subject key identifier (if present) and issuer and
347 serial number of the candidate issuer, in addition the keyUsage extension of
348 the candidate issuer (if present) must permit certificate signing.
350 The lookup first looks in the list of untrusted certificates and if no match
351 is found the remaining lookups are from the trusted certificates. The root CA
352 is always looked up in the trusted certificate list: if the certificate to
353 verify is a root certificate then an exact match must be found in the trusted
356 The second operation is to check every untrusted certificate's extensions for
357 consistency with the supplied purpose. If the B<-purpose> option is not included
358 then no checks are done. The supplied or "leaf" certificate must have extensions
359 compatible with the supplied purpose and all other certificates must also be valid
360 CA certificates. The precise extensions required are described in more detail in
361 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
363 The third operation is to check the trust settings on the root CA. The root CA
364 should be trusted for the supplied purpose.
365 For compatibility with previous versions of OpenSSL, a certificate with no
366 trust settings is considered to be valid for all purposes.
368 The final operation is to check the validity of the certificate chain. The validity
369 period is checked against the current system time and the notBefore and notAfter
370 dates in the certificate. The certificate signatures are also checked at this
373 If all operations complete successfully then certificate is considered valid. If
374 any operation fails then the certificate is not valid.
378 When a verify operation fails the output messages can be somewhat cryptic. The
379 general form of the error message is:
381 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
382 error 24 at 1 depth lookup:invalid CA certificate
384 The first line contains the name of the certificate being verified followed by
385 the subject name of the certificate. The second line contains the error number
386 and the depth. The depth is number of the certificate being verified when a
387 problem was detected starting with zero for the certificate being verified itself
388 then 1 for the CA that signed the certificate and so on. Finally a text version
389 of the error number is presented.
391 A partial list of the error codes and messages is shown below, this also
392 includes the name of the error code as defined in the header file x509_vfy.h
393 Some of the error codes are defined but never returned: these are described
400 The operation was successful.
402 =item B<X509_V_ERR_UNSPECIFIED>
404 Unspecified error; should not happen.
406 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT>
408 The issuer certificate of a looked up certificate could not be found. This
409 normally means the list of trusted certificates is not complete.
411 =item B<X509_V_ERR_UNABLE_TO_GET_CRL>
413 The CRL of a certificate could not be found.
415 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE>
417 The certificate signature could not be decrypted. This means that the actual signature value
418 could not be determined rather than it not matching the expected value, this is only
419 meaningful for RSA keys.
421 =item B<X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE>
423 The CRL signature could not be decrypted: this means that the actual signature value
424 could not be determined rather than it not matching the expected value. Unused.
426 =item B<X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY>
428 The public key in the certificate SubjectPublicKeyInfo could not be read.
430 =item B<X509_V_ERR_CERT_SIGNATURE_FAILURE>
432 The signature of the certificate is invalid.
434 =item B<X509_V_ERR_CRL_SIGNATURE_FAILURE>
436 The signature of the certificate is invalid.
438 =item B<X509_V_ERR_CERT_NOT_YET_VALID>
440 The certificate is not yet valid: the notBefore date is after the current time.
442 =item B<X509_V_ERR_CERT_HAS_EXPIRED>
444 The certificate has expired: that is the notAfter date is before the current time.
446 =item B<X509_V_ERR_CRL_NOT_YET_VALID>
448 The CRL is not yet valid.
450 =item B<X509_V_ERR_CRL_HAS_EXPIRED>
454 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD>
456 The certificate notBefore field contains an invalid time.
458 =item B<X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD>
460 The certificate notAfter field contains an invalid time.
462 =item B<X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD>
464 The CRL lastUpdate field contains an invalid time.
466 =item B<X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD>
468 The CRL nextUpdate field contains an invalid time.
470 =item B<X509_V_ERR_OUT_OF_MEM>
472 An error occurred trying to allocate memory. This should never happen.
474 =item B<X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT>
476 The passed certificate is self-signed and the same certificate cannot be found in the list of
477 trusted certificates.
479 =item B<X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN>
481 The certificate chain could be built up using the untrusted certificates but the root could not
484 =item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY>
486 The issuer certificate could not be found: this occurs if the issuer
487 certificate of an untrusted certificate cannot be found.
489 =item B<X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE>
491 No signatures could be verified because the chain contains only one certificate and it is not
494 =item B<X509_V_ERR_CERT_CHAIN_TOO_LONG>
496 The certificate chain length is greater than the supplied maximum depth. Unused.
498 =item B<X509_V_ERR_CERT_REVOKED>
500 The certificate has been revoked.
502 =item B<X509_V_ERR_INVALID_CA>
504 A CA certificate is invalid. Either it is not a CA or its extensions are not consistent
505 with the supplied purpose.
507 =item B<X509_V_ERR_PATH_LENGTH_EXCEEDED>
509 The basicConstraints pathlength parameter has been exceeded.
511 =item B<X509_V_ERR_INVALID_PURPOSE>
513 The supplied certificate cannot be used for the specified purpose.
515 =item B<X509_V_ERR_CERT_UNTRUSTED>
517 the root CA is not marked as trusted for the specified purpose.
519 =item B<X509_V_ERR_CERT_REJECTED>
521 The root CA is marked to reject the specified purpose.
523 =item B<X509_V_ERR_SUBJECT_ISSUER_MISMATCH>
525 not used as of OpenSSL 1.1.0 as a result of the deprecation of the
526 B<-issuer_checks> option.
528 =item B<X509_V_ERR_AKID_SKID_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_ISSUER_SERIAL_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_KEYUSAGE_NO_CERTSIGN>
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_UNABLE_TO_GET_CRL_ISSUER>
545 Unable to get CRL issuer certificate.
547 =item B<X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION>
549 Unhandled critical extension.
551 =item B<X509_V_ERR_KEYUSAGE_NO_CRL_SIGN>
553 Key usage does not include CRL signing.
555 =item B<X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION>
557 Unhandled critical CRL extension.
559 =item B<X509_V_ERR_INVALID_NON_CA>
561 Invalid non-CA certificate has CA markings.
563 =item B<X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED>
565 Proxy path length constraint exceeded.
567 =item B<X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE>
569 Key usage does not include digital signature.
571 =item B<X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED>
573 Proxy certificates not allowed, please set the appropriate flag.
575 =item B<X509_V_ERR_INVALID_EXTENSION>
577 Invalid or inconsistent certificate extension.
579 =item B<X509_V_ERR_INVALID_POLICY_EXTENSION>
581 Invalid or inconsistent certificate policy extension.
583 =item B<X509_V_ERR_NO_EXPLICIT_POLICY>
587 =item B<X509_V_ERR_DIFFERENT_CRL_SCOPE>
591 =item B<X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE>
593 Unsupported extension feature.
595 =item B<X509_V_ERR_UNNESTED_RESOURCE>
597 RFC 3779 resource not subset of parent's resources.
599 =item B<X509_V_ERR_PERMITTED_VIOLATION>
601 Permitted subtree violation.
603 =item B<X509_V_ERR_EXCLUDED_VIOLATION>
605 Excluded subtree violation.
607 =item B<X509_V_ERR_SUBTREE_MINMAX>
609 Name constraints minimum and maximum not supported.
611 =item B<X509_V_ERR_APPLICATION_VERIFICATION>
613 Application verification failure. Unused.
615 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE>
617 Unsupported name constraint type.
619 =item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX>
621 Unsupported or invalid name constraint syntax.
623 =item B<X509_V_ERR_UNSUPPORTED_NAME_SYNTAX>
625 Unsupported or invalid name syntax.
627 =item B<X509_V_ERR_CRL_PATH_VALIDATION_ERROR>
629 CRL path validation error.
631 =item B<X509_V_ERR_PATH_LOOP>
635 =item B<X509_V_ERR_SUITE_B_INVALID_VERSION>
637 Suite B: certificate version invalid.
639 =item B<X509_V_ERR_SUITE_B_INVALID_ALGORITHM>
641 Suite B: invalid public key algorithm.
643 =item B<X509_V_ERR_SUITE_B_INVALID_CURVE>
645 Suite B: invalid ECC curve.
647 =item B<X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM>
649 Suite B: invalid signature algorithm.
651 =item B<X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED>
653 Suite B: curve not allowed for this LOS.
655 =item B<X509_V_ERR_SUITE_B_CANNOT_SIGN_P_384_WITH_P_256>
657 Suite B: cannot sign P-384 with P-256.
659 =item B<X509_V_ERR_HOSTNAME_MISMATCH>
663 =item B<X509_V_ERR_EMAIL_MISMATCH>
665 Email address mismatch.
667 =item B<X509_V_ERR_IP_ADDRESS_MISMATCH>
671 =item B<X509_V_ERR_DANE_NO_MATCH>
673 DANE TLSA authentication is enabled, but no TLSA records matched the
675 This error is only possible in L<s_client(1)>.
681 Although the issuer checks are a considerable improvement over the old technique they still
682 suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that
683 trusted certificates with matching subject name must either appear in a file (as specified by the
684 B<-CAfile> option) or a directory (as specified by B<-CApath>). If they occur in both then only
685 the certificates in the file will be recognised.
687 Previous versions of OpenSSL assume certificates with matching subject name are identical and
690 Previous versions of this documentation swapped the meaning of the
691 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
692 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
700 The B<-show_chain> option was first added to OpenSSL 1.1.0.
702 The B<-issuer_checks> option is deprecated as of OpenSSL 1.1.0 and
707 Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
709 Licensed under the OpenSSL license (the "License"). You may not use
710 this file except in compliance with the License. You can obtain a copy
711 in the file LICENSE in the source distribution or at
712 L<https://www.openssl.org/source/license.html>.