5 verify - Utility to verify certificates.
11 [B<-CApath directory>]
12 [B<-attime timestamp>]
39 [B<-verify_depth num>]
40 [B<-verify_email email>]
41 [B<-verify_hostname hostname>]
43 [B<-verify_name name>]
51 The B<verify> command verifies certificate chains.
53 =head1 COMMAND OPTIONS
59 A file of trusted certificates. The file should contain multiple certificates
60 in PEM format concatenated together.
62 =item B<-CApath directory>
64 A directory of trusted certificates. The certificates should have names
65 of the form: hash.0 or have symbolic links to them of this
66 form ("hash" is the hashed certificate subject name: see the B<-hash> option
67 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
68 create symbolic links to a directory of certificates.
70 =item B<-attime timestamp>
72 Perform validation checks using time specified by B<timestamp> and not
73 current system time. B<timestamp> is the number of seconds since
74 01.01.1970 (UNIX time).
76 =item B<-check_ss_sig>
78 Verify the signature on the self-signed root CA. This is disabled by default
79 because it doesn't add any security.
81 =item B<-CRLfile file>
83 File containing one or more CRL's (in PEM format) to load.
85 =item B<-crl_download>
87 Attempt to download CRL information for this certificate.
91 Checks end entity certificate validity by attempting to look up a valid CRL.
92 If a valid CRL cannot be found an error occurs.
94 =item B<-crl_check_all>
96 Checks the validity of B<all> certificates in the chain by attempting
97 to look up valid CRLs.
99 =item B<-explicit_policy>
101 Set policy variable require-explicit-policy (see RFC5280).
103 =item B<-extended_crl>
105 Enable extended CRL features such as indirect CRLs and alternate CRL
110 Print out a usage message.
112 =item B<-ignore_critical>
114 Normally if an unhandled critical extension is present which is not
115 supported by OpenSSL the certificate is rejected (as required by RFC5280).
116 If this option is set critical extensions are ignored.
118 =item B<-inhibit_any>
120 Set policy variable inhibit-any-policy (see RFC5280).
122 =item B<-inhibit_map>
124 Set policy variable inhibit-policy-mapping (see RFC5280).
126 =item B<-issuer_checks>
128 Print out diagnostics relating to searches for the issuer certificate of the
129 current certificate. This shows why each candidate issuer certificate was
130 rejected. The presence of rejection messages does not itself imply that
131 anything is wrong; during the normal verification process, several
132 rejections may take place.
134 =item B<-partial_chain>
136 Allow partial certificate chain if at least one certificate is in trusted store.
140 Enable policy processing and add B<arg> to the user-initial-policy-set (see
141 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
142 This argument can appear more than once.
144 =item B<-policy_check>
146 Enables certificate policy processing.
148 =item B<-policy_print>
150 Print out diagnostics related to policy processing.
152 =item B<-purpose purpose>
154 The intended use for the certificate. If this option is not specified,
155 B<verify> will not consider certificate purpose during chain verification.
156 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
157 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
160 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
162 enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
163 192 bit, or only 192 bit Level of Security respectively.
164 See RFC6460 for details. In particular the supported signature algorithms are
165 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
168 =item B<-trusted_first>
170 Use certificates in CA file or CA directory before certificates in untrusted
171 file when building the trust chain to verify certificates.
172 This is mainly useful in environments with Bridge CA or Cross-Certified CAs.
174 =item B<-no_alt_chains>
176 When building a certificate chain, if the first certificate chain found is not
177 trusted, then OpenSSL will continue to check to see if an alternative chain can
178 be found that is trusted. With this option that behaviour is suppressed so that
179 only the first chain found is ever used. Using this option will force the
180 behaviour to match that of OpenSSL versions prior to 1.1.0.
182 =item B<-untrusted file>
184 A file of untrusted certificates. The file should contain multiple certificates
185 in PEM format concatenated together.
187 =item B<-trusted file>
189 A file of additional trusted certificates. The file should contain multiple
190 certificates in PEM format concatenated together.
194 Enable support for delta CRLs.
198 Print extra information about the operations being performed.
200 =item B<-verify_depth num>
202 Limit the maximum depth of the certificate chain to B<num> certificates.
204 =item B<-verify_email email>
206 Verify if the B<email> matches the email address in Subject Alternative Name or
207 the email in the subject Distinguished Name.
209 =item B<-verify_hostname hostname>
211 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
212 Common Name in the subject certificate.
214 =item B<-verify_ip ip>
216 Verify if the B<ip> matches the IP address in Subject Alternative Name of
217 the subject certificate.
219 =item B<-verify_name name>
221 Use default verification options like trust model and required certificate
222 policies identified by B<name>.
223 Supported usages include: default, pkcs7, smime_sign, ssl_client, ssl_server.
225 =item B<-x509_strict>
227 For strict X.509 compliance, disable non-compliant workarounds for broken
232 Indicates the last option. All arguments following this are assumed to be
233 certificate files. This is useful if the first certificate filename begins
236 =item B<certificates>
238 One or more certificates to verify. If no certificates are given, B<verify>
239 will attempt to read a certificate from standard input. Certificates must be
244 =head1 VERIFY OPERATION
246 The B<verify> program uses the same functions as the internal SSL and S/MIME
247 verification, therefore this description applies to these verify operations
250 There is one crucial difference between the verify operations performed
251 by the B<verify> program: wherever possible an attempt is made to continue
252 after an error whereas normally the verify operation would halt on the
253 first error. This allows all the problems with a certificate chain to be
256 The verify operation consists of a number of separate steps.
258 Firstly a certificate chain is built up starting from the supplied certificate
259 and ending in the root CA. It is an error if the whole chain cannot be built
260 up. The chain is built up by looking up the issuers certificate of the current
261 certificate. If a certificate is found which is its own issuer it is assumed
264 The process of 'looking up the issuers certificate' itself involves a number
265 of steps. In versions of OpenSSL before 0.9.5a the first certificate whose
266 subject name matched the issuer of the current certificate was assumed to be
267 the issuers certificate. In OpenSSL 0.9.6 and later all certificates
268 whose subject name matches the issuer name of the current certificate are
269 subject to further tests. The relevant authority key identifier components
270 of the current certificate (if present) must match the subject key identifier
271 (if present) and issuer and serial number of the candidate issuer, in addition
272 the keyUsage extension of the candidate issuer (if present) must permit
275 The lookup first looks in the list of untrusted certificates and if no match
276 is found the remaining lookups are from the trusted certificates. The root CA
277 is always looked up in the trusted certificate list: if the certificate to
278 verify is a root certificate then an exact match must be found in the trusted
281 The second operation is to check every untrusted certificate's extensions for
282 consistency with the supplied purpose. If the B<-purpose> option is not included
283 then no checks are done. The supplied or "leaf" certificate must have extensions
284 compatible with the supplied purpose and all other certificates must also be valid
285 CA certificates. The precise extensions required are described in more detail in
286 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
288 The third operation is to check the trust settings on the root CA. The root
289 CA should be trusted for the supplied purpose. For compatibility with previous
290 versions of SSLeay and OpenSSL a certificate with no trust settings is considered
291 to be valid for all purposes.
293 The final operation is to check the validity of the certificate chain. The validity
294 period is checked against the current system time and the notBefore and notAfter
295 dates in the certificate. The certificate signatures are also checked at this
298 If all operations complete successfully then certificate is considered valid. If
299 any operation fails then the certificate is not valid.
303 When a verify operation fails the output messages can be somewhat cryptic. The
304 general form of the error message is:
306 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
307 error 24 at 1 depth lookup:invalid CA certificate
309 The first line contains the name of the certificate being verified followed by
310 the subject name of the certificate. The second line contains the error number
311 and the depth. The depth is number of the certificate being verified when a
312 problem was detected starting with zero for the certificate being verified itself
313 then 1 for the CA that signed the certificate and so on. Finally a text version
314 of the error number is presented.
316 An exhaustive list of the error codes and messages is shown below, this also
317 includes the name of the error code as defined in the header file x509_vfy.h
318 Some of the error codes are defined but never returned: these are described
323 =item B<0 X509_V_OK: ok>
325 the operation was successful.
327 =item B<2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate>
329 the issuer certificate of a looked up certificate could not be found. This
330 normally means the list of trusted certificates is not complete.
332 =item B<3 X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL>
334 the CRL of a certificate could not be found.
336 =item B<4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt certificate's signature>
338 the certificate signature could not be decrypted. This means that the actual signature value
339 could not be determined rather than it not matching the expected value, this is only
340 meaningful for RSA keys.
342 =item B<5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's signature>
344 the CRL signature could not be decrypted: this means that the actual signature value
345 could not be determined rather than it not matching the expected value. Unused.
347 =item B<6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer public key>
349 the public key in the certificate SubjectPublicKeyInfo could not be read.
351 =item B<7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure>
353 the signature of the certificate is invalid.
355 =item B<8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure>
357 the signature of the certificate is invalid.
359 =item B<9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid>
361 the certificate is not yet valid: the notBefore date is after the current time.
363 =item B<10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired>
365 the certificate has expired: that is the notAfter date is before the current time.
367 =item B<11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid>
369 the CRL is not yet valid.
371 =item B<12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired>
375 =item B<13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field>
377 the certificate notBefore field contains an invalid time.
379 =item B<14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field>
381 the certificate notAfter field contains an invalid time.
383 =item B<15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field>
385 the CRL lastUpdate field contains an invalid time.
387 =item B<16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field>
389 the CRL nextUpdate field contains an invalid time.
391 =item B<17 X509_V_ERR_OUT_OF_MEM: out of memory>
393 an error occurred trying to allocate memory. This should never happen.
395 =item B<18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate>
397 the passed certificate is self signed and the same certificate cannot be found in the list of
398 trusted certificates.
400 =item B<19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in certificate chain>
402 the certificate chain could be built up using the untrusted certificates but the root could not
405 =item B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate>
407 the issuer certificate could not be found: this occurs if the issuer
408 certificate of an untrusted certificate cannot be found.
410 =item B<21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first certificate>
412 no signatures could be verified because the chain contains only one certificate and it is not
415 =item B<22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long>
417 the certificate chain length is greater than the supplied maximum depth. Unused.
419 =item B<23 X509_V_ERR_CERT_REVOKED: certificate revoked>
421 the certificate has been revoked.
423 =item B<24 X509_V_ERR_INVALID_CA: invalid CA certificate>
425 a CA certificate is invalid. Either it is not a CA or its extensions are not consistent
426 with the supplied purpose.
428 =item B<25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded>
430 the basicConstraints pathlength parameter has been exceeded.
432 =item B<26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose>
434 the supplied certificate cannot be used for the specified purpose.
436 =item B<27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted>
438 the root CA is not marked as trusted for the specified purpose.
440 =item B<28 X509_V_ERR_CERT_REJECTED: certificate rejected>
442 the root CA is marked to reject the specified purpose.
444 =item B<29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch>
446 the current candidate issuer certificate was rejected because its subject name
447 did not match the issuer name of the current certificate. Only displayed when
448 the B<-issuer_checks> option is set.
450 =item B<30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier mismatch>
452 the current candidate issuer certificate was rejected because its subject key
453 identifier was present and did not match the authority key identifier current
454 certificate. Only displayed when the B<-issuer_checks> option is set.
456 =item B<31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial number mismatch>
458 the current candidate issuer certificate was rejected because its issuer name
459 and serial number was present and did not match the authority key identifier
460 of the current certificate. Only displayed when the B<-issuer_checks> option is set.
462 =item B<32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate signing>
464 the current candidate issuer certificate was rejected because its keyUsage extension
465 does not permit certificate signing.
467 =item B<50 X509_V_ERR_APPLICATION_VERIFICATION: application verification failure>
469 an application specific error. Unused.
475 Although the issuer checks are a considerable improvement over the old technique they still
476 suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that
477 trusted certificates with matching subject name must either appear in a file (as specified by the
478 B<-CAfile> option) or a directory (as specified by B<-CApath>). If they occur in both then only
479 the certificates in the file will be recognised.
481 Previous versions of OpenSSL assume certificates with matching subject name are identical and
484 Previous versions of this documentation swapped the meaning of the
485 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
486 B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
494 The -no_alt_chains options was first added to OpenSSL 1.1.0.