5 verify - Utility to verify certificates.
12 [B<-CApath directory>]
15 [B<-attime timestamp>]
42 [B<-verify_depth num>]
43 [B<-verify_email email>]
44 [B<-verify_hostname hostname>]
46 [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
102 If you want to enable an B<engine> via the B<-engine> option, that option has
103 to be specified before this one.
105 =item B<-crl_download>
107 Attempt to download CRL information for this certificate.
111 Checks end entity certificate validity by attempting to look up a valid CRL.
112 If a valid CRL cannot be found an error occurs.
114 =item B<-crl_check_all>
116 Checks the validity of B<all> certificates in the chain by attempting
117 to look up valid CRLs.
121 Specifying an engine B<id> will cause L<verify(1)> to attempt to load the
123 The engine will then be set as the default for all its supported algorithms.
124 If you want to load certificates or CRLs that require engine support via any of
125 the B<-trusted>, B<-untrusted> or B<-CRLfile> options, the B<-engine> option
126 must be specified before those options.
128 =item B<-explicit_policy>
130 Set policy variable require-explicit-policy (see RFC5280).
132 =item B<-extended_crl>
134 Enable extended CRL features such as indirect CRLs and alternate CRL
137 =item B<-ignore_critical>
139 Normally if an unhandled critical extension is present which is not
140 supported by OpenSSL the certificate is rejected (as required by RFC5280).
141 If this option is set critical extensions are ignored.
143 =item B<-inhibit_any>
145 Set policy variable inhibit-any-policy (see RFC5280).
147 =item B<-inhibit_map>
149 Set policy variable inhibit-policy-mapping (see RFC5280).
151 =item B<-issuer_checks>
153 Print out diagnostics relating to searches for the issuer certificate of the
154 current certificate. This shows why each candidate issuer certificate was
155 rejected. The presence of rejection messages does not itself imply that
156 anything is wrong; during the normal verification process, several
157 rejections may take place.
159 =item B<-partial_chain>
161 Allow verification to succeed even if a I<complete> chain cannot be built to a
162 self-signed trust-anchor, provided it is possible to construct a chain to a
163 trusted certificate that might not be self-signed.
167 Enable policy processing and add B<arg> to the user-initial-policy-set (see
168 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
169 This argument can appear more than once.
171 =item B<-policy_check>
173 Enables certificate policy processing.
175 =item B<-policy_print>
177 Print out diagnostics related to policy processing.
179 =item B<-purpose purpose>
181 The intended use for the certificate. If this option is not specified,
182 B<verify> will not consider certificate purpose during chain verification.
183 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
184 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
187 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
189 enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
190 192 bit, or only 192 bit Level of Security respectively.
191 See RFC6460 for details. In particular the supported signature algorithms are
192 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
195 =item B<-trusted_first>
197 When constructing the certificate chain, use the trusted certificates specified
198 via B<-CAfile>, B<-CApath> or B<-trusted> before any certificates specified via
200 This can be useful in environments with Bridge or Cross-Certified CAs.
201 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
203 =item B<-no_alt_chains>
205 By default, unless B<-trusted_first> is specified, when building a certificate
206 chain, if the first certificate chain found is not trusted, then OpenSSL will
207 attempt to replace untrusted issuer certificates with certificates from the
208 trust store to see if an alternative chain can be found that is trusted.
209 As of OpenSSL 1.1.0, with B<-trusted_first> always on, this option has no
212 =item B<-untrusted file>
214 A B<file> of additional untrusted certificates (intermediate issuer CAs) used
215 to constuct a certificate chain from the subject certificate to a trust-anchor.
216 The B<file> should contain one or more certificates in PEM format.
217 This option can be specified more than once to include untrusted certiificates
218 from multiple B<files>.
219 If you want to enable an B<engine> via the B<-engine> option, that option has
220 to be specified before this one.
222 =item B<-trusted file>
224 A B<file> of trusted certificates, which must be self-signed, unless the
225 B<-partial_chain> option is specified.
226 The B<file> contain one or more certificates in PEM format.
227 With this option, no additional (e.g., default) certificate lists are
229 That is, the only trust-anchors are those listed in B<file>.
230 This option can be specified more than once to include trusted certificates
231 from multiple B<files>.
232 This option implies the B<-no-CAfile> and B<-no-CApath> options.
233 This option cannot be used in combination with either of the B<-CAfile> or
235 If you want to enable an B<engine> via the B<-engine> option, that option has
236 to be specified before this one.
240 Enable support for delta CRLs.
244 Print extra information about the operations being performed.
246 =item B<-verify_depth num>
248 Limit the maximum depth of the certificate chain to B<num> certificates.
250 =item B<-verify_email email>
252 Verify if the B<email> matches the email address in Subject Alternative Name or
253 the email in the subject Distinguished Name.
255 =item B<-verify_hostname hostname>
257 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
258 Common Name in the subject certificate.
260 =item B<-verify_ip ip>
262 Verify if the B<ip> matches the IP address in Subject Alternative Name of
263 the subject certificate.
265 =item B<-verify_name name>
267 Use default verification policies like trust model and required certificate
268 policies identified by B<name>.
269 The trust model determines which auxiliary trust or reject OIDs are applicable
270 to verifying the given certificate chain.
271 See the B<-addtrust> and B<-addreject> options of the L<x509(1)> command-line
273 Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
274 B<ssl_client>, B<ssl_server>.
275 These mimics the combinations of purpose and trust settings used in SSL, CMS
277 As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
278 specified, so the B<-verify_name> options are functionally equivalent to the
279 corresponding B<-purpose> settings.
281 =item B<-x509_strict>
283 For strict X.509 compliance, disable non-compliant workarounds for broken
288 Display information about the certificate chain that has been built (if
289 successful). Certificates in the chain that came from the untrusted list will be
290 flagged as "untrusted".
294 Indicates the last option. All arguments following this are assumed to be
295 certificate files. This is useful if the first certificate filename begins
298 =item B<certificates>
300 One or more certificates to verify. If no certificates are given, B<verify>
301 will attempt to read a certificate from standard input. Certificates must be
306 =head1 VERIFY OPERATION
308 The B<verify> program uses the same functions as the internal SSL and S/MIME
309 verification, therefore this description applies to these verify operations
312 There is one crucial difference between the verify operations performed
313 by the B<verify> program: wherever possible an attempt is made to continue
314 after an error whereas normally the verify operation would halt on the
315 first error. This allows all the problems with a certificate chain to be
318 The verify operation consists of a number of separate steps.
320 Firstly a certificate chain is built up starting from the supplied certificate
321 and ending in the root CA.
322 It is an error if the whole chain cannot be built up.
323 The chain is built up by looking up the issuers certificate of the current
325 If a certificate is found which is its own issuer it is assumed to be the root
328 The process of 'looking up the issuers certificate' itself involves a number of
330 Ater all certificates whose subject name matches the issuer name of the current
331 certificate are subject to further tests.
332 The relevant authority key identifier components of the current certificate (if
333 present) must match the subject key identifier (if present) and issuer and
334 serial number of the candidate issuer, in addition the keyUsage extension of
335 the candidate issuer (if present) must permit certificate signing.
337 The lookup first looks in the list of untrusted certificates and if no match
338 is found the remaining lookups are from the trusted certificates. The root CA
339 is always looked up in the trusted certificate list: if the certificate to
340 verify is a root certificate then an exact match must be found in the trusted
343 The second operation is to check every untrusted certificate's extensions for
344 consistency with the supplied purpose. If the B<-purpose> option is not included
345 then no checks are done. The supplied or "leaf" certificate must have extensions
346 compatible with the supplied purpose and all other certificates must also be valid
347 CA certificates. The precise extensions required are described in more detail in
348 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
350 The third operation is to check the trust settings on the root CA. The root CA
351 should be trusted for the supplied purpose.
352 For compatibility with previous versions of OpenSSL, a certificate with no
353 trust settings is considered to be valid for all purposes.
355 The final operation is to check the validity of the certificate chain. The validity
356 period is checked against the current system time and the notBefore and notAfter
357 dates in the certificate. The certificate signatures are also checked at this
360 If all operations complete successfully then certificate is considered valid. If
361 any operation fails then the certificate is not valid.
365 When a verify operation fails the output messages can be somewhat cryptic. The
366 general form of the error message is:
368 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
369 error 24 at 1 depth lookup:invalid CA certificate
371 The first line contains the name of the certificate being verified followed by
372 the subject name of the certificate. The second line contains the error number
373 and the depth. The depth is number of the certificate being verified when a
374 problem was detected starting with zero for the certificate being verified itself
375 then 1 for the CA that signed the certificate and so on. Finally a text version
376 of the error number is presented.
378 An partial list of the error codes and messages is shown below, this also
379 includes the name of the error code as defined in the header file x509_vfy.h
380 Some of the error codes are defined but never returned: these are described
385 =item B<0 X509_V_OK: ok>
387 the operation was successful.
389 =item B<2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate>
391 the issuer certificate of a looked up certificate could not be found. This
392 normally means the list of trusted certificates is not complete.
394 =item B<3 X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL>
396 the CRL of a certificate could not be found.
398 =item B<4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt certificate's signature>
400 the certificate signature could not be decrypted. This means that the actual signature value
401 could not be determined rather than it not matching the expected value, this is only
402 meaningful for RSA keys.
404 =item B<5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's signature>
406 the CRL signature could not be decrypted: this means that the actual signature value
407 could not be determined rather than it not matching the expected value. Unused.
409 =item B<6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer public key>
411 the public key in the certificate SubjectPublicKeyInfo could not be read.
413 =item B<7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure>
415 the signature of the certificate is invalid.
417 =item B<8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure>
419 the signature of the certificate is invalid.
421 =item B<9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid>
423 the certificate is not yet valid: the notBefore date is after the current time.
425 =item B<10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired>
427 the certificate has expired: that is the notAfter date is before the current time.
429 =item B<11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid>
431 the CRL is not yet valid.
433 =item B<12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired>
437 =item B<13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field>
439 the certificate notBefore field contains an invalid time.
441 =item B<14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field>
443 the certificate notAfter field contains an invalid time.
445 =item B<15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field>
447 the CRL lastUpdate field contains an invalid time.
449 =item B<16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field>
451 the CRL nextUpdate field contains an invalid time.
453 =item B<17 X509_V_ERR_OUT_OF_MEM: out of memory>
455 an error occurred trying to allocate memory. This should never happen.
457 =item B<18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate>
459 the passed certificate is self signed and the same certificate cannot be found in the list of
460 trusted certificates.
462 =item B<19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in certificate chain>
464 the certificate chain could be built up using the untrusted certificates but the root could not
467 =item B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate>
469 the issuer certificate could not be found: this occurs if the issuer
470 certificate of an untrusted certificate cannot be found.
472 =item B<21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first certificate>
474 no signatures could be verified because the chain contains only one certificate and it is not
477 =item B<22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long>
479 the certificate chain length is greater than the supplied maximum depth. Unused.
481 =item B<23 X509_V_ERR_CERT_REVOKED: certificate revoked>
483 the certificate has been revoked.
485 =item B<24 X509_V_ERR_INVALID_CA: invalid CA certificate>
487 a CA certificate is invalid. Either it is not a CA or its extensions are not consistent
488 with the supplied purpose.
490 =item B<25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded>
492 the basicConstraints pathlength parameter has been exceeded.
494 =item B<26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose>
496 the supplied certificate cannot be used for the specified purpose.
498 =item B<27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted>
500 the root CA is not marked as trusted for the specified purpose.
502 =item B<28 X509_V_ERR_CERT_REJECTED: certificate rejected>
504 the root CA is marked to reject the specified purpose.
506 =item B<29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch>
508 the current candidate issuer certificate was rejected because its subject name
509 did not match the issuer name of the current certificate. Only displayed when
510 the B<-issuer_checks> option is set.
512 =item B<30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier mismatch>
514 the current candidate issuer certificate was rejected because its subject key
515 identifier was present and did not match the authority key identifier current
516 certificate. Only displayed when the B<-issuer_checks> option is set.
518 =item B<31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial number mismatch>
520 the current candidate issuer certificate was rejected because its issuer name
521 and serial number was present and did not match the authority key identifier
522 of the current certificate. Only displayed when the B<-issuer_checks> option is set.
524 =item B<32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate signing>
526 the current candidate issuer certificate was rejected because its keyUsage extension
527 does not permit certificate signing.
529 =item B<50 X509_V_ERR_APPLICATION_VERIFICATION: application verification failure>
531 an application specific error. Unused.
537 Although the issuer checks are a considerable improvement over the old technique they still
538 suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that
539 trusted certificates with matching subject name must either appear in a file (as specified by the
540 B<-CAfile> option) or a directory (as specified by B<-CApath>). If they occur in both then only
541 the certificates in the file will be recognised.
543 Previous versions of OpenSSL assume certificates with matching subject name are identical and
546 Previous versions of this documentation swapped the meaning of the
547 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
548 B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
556 The -show_chain option was first added to OpenSSL 1.1.0.