5 verify - Utility to verify certificates.
11 [B<-CApath directory>]
12 [B<-attime timestamp>]
37 [B<-verify_depth num>]
38 [B<-verify_email email>]
39 [B<-verify_hostname hostname>]
41 [B<-verify_name name>]
49 The B<verify> command verifies certificate chains.
51 =head1 COMMAND OPTIONS
57 A file of trusted certificates. The file should contain multiple certificates
58 in PEM format concatenated together.
60 =item B<-CApath directory>
62 A directory of trusted certificates. The certificates should have names
63 of the form: hash.0 or have symbolic links to them of this
64 form ("hash" is the hashed certificate subject name: see the B<-hash> option
65 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
66 create symbolic links to a directory of certificates.
68 =item B<-attime timestamp>
70 Perform validation checks using time specified by B<timestamp> and not
71 current system time. B<timestamp> is the number of seconds since
72 01.01.1970 (UNIX time).
74 =item B<-check_ss_sig>
76 Verify the signature on the self-signed root CA. This is disabled by default
77 because it doesn't add any security.
79 =item B<-crlfile file>
81 File containing one or more CRL's (in PEM format) to load.
85 Checks end entity certificate validity by attempting to look up a valid CRL.
86 If a valid CRL cannot be found an error occurs.
88 =item B<-crl_check_all>
90 Checks the validity of B<all> certificates in the chain by attempting
91 to look up valid CRLs.
93 =item B<-explicit_policy>
95 Set policy variable require-explicit-policy (see RFC5280).
97 =item B<-extended_crl>
99 Enable extended CRL features such as indirect CRLs and alternate CRL
104 Print out a usage message.
106 =item B<-ignore_critical>
108 Normally if an unhandled critical extension is present which is not
109 supported by OpenSSL the certificate is rejected (as required by RFC5280).
110 If this option is set critical extensions are ignored.
112 =item B<-inhibit_any>
114 Set policy variable inhibit-any-policy (see RFC5280).
116 =item B<-inhibit_map>
118 Set policy variable inhibit-policy-mapping (see RFC5280).
120 =item B<-issuer_checks>
122 Print out diagnostics relating to searches for the issuer certificate of the
123 current certificate. This shows why each candidate issuer certificate was
124 rejected. The presence of rejection messages does not itself imply that
125 anything is wrong; during the normal verification process, several
126 rejections may take place.
128 =item B<-partial_chain>
130 Allow partial certificate chain if at least one certificate is in trusted store.
134 Enable policy processing and add B<arg> to the user-initial-policy-set (see
135 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
136 This argument can appear more than once.
138 =item B<-policy_check>
140 Enables certificate policy processing.
142 =item B<-policy_print>
144 Print out diagnostics related to policy processing.
146 =item B<-purpose purpose>
148 The intended use for the certificate. If this option is not specified,
149 B<verify> will not consider certificate purpose during chain verification.
150 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
151 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
154 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
156 enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
157 192 bit, or only 192 bit Level of Security respectively.
158 See RFC6460 for details. In particular the supported signature algorithms are
159 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
162 =item B<-trusted_first>
164 Use certificates in CA file or CA directory before certificates in untrusted
165 file when building the trust chain to verify certificates.
166 This is mainly useful in environments with Bridge CA or Cross-Certified CAs.
168 =item B<-no_alt_chains>
170 When building a certificate chain, if the first certificate chain found is not
171 trusted, then OpenSSL will continue to check to see if an alternative chain can
172 be found that is trusted. With this option that behaviour is suppressed so that
173 only the first chain found is ever used. Using this option will force the
174 behaviour to match that of OpenSSL versions prior to 1.1.0.
176 =item B<-untrusted file>
178 A file of untrusted certificates. The file should contain multiple certificates
179 in PEM format concatenated together.
183 Enable support for delta CRLs.
187 Print extra information about the operations being performed.
189 =item B<-verify_depth num>
191 Limit the maximum depth of the certificate chain to B<num> certificates.
193 =item B<-verify_email email>
195 Verify if the B<email> matches the email address in Subject Alternative Name or
196 the email in the subject Distinguished Name.
198 =item B<-verify_hostname hostname>
200 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
201 Common Name in the subject certificate.
203 =item B<-verify_ip ip>
205 Verify if the B<ip> matches the IP address in Subject Alternative Name of
206 the subject certificate.
208 =item B<-verify_name name>
210 Use default verification options like trust model and required certificate
211 policies identified by B<name>.
212 Supported usages include: default, pkcs7, smime_sign, ssl_client, ssl_server.
214 =item B<-x509_strict>
216 For strict X.509 compliance, disable non-compliant workarounds for broken
221 Indicates the last option. All arguments following this are assumed to be
222 certificate files. This is useful if the first certificate filename begins
225 =item B<certificates>
227 One or more certificates to verify. If no certificates are given, B<verify>
228 will attempt to read a certificate from standard input. Certificates must be
233 =head1 VERIFY OPERATION
235 The B<verify> program uses the same functions as the internal SSL and S/MIME
236 verification, therefore this description applies to these verify operations
239 There is one crucial difference between the verify operations performed
240 by the B<verify> program: wherever possible an attempt is made to continue
241 after an error whereas normally the verify operation would halt on the
242 first error. This allows all the problems with a certificate chain to be
245 The verify operation consists of a number of separate steps.
247 Firstly a certificate chain is built up starting from the supplied certificate
248 and ending in the root CA. It is an error if the whole chain cannot be built
249 up. The chain is built up by looking up the issuers certificate of the current
250 certificate. If a certificate is found which is its own issuer it is assumed
253 The process of 'looking up the issuers certificate' itself involves a number
254 of steps. In versions of OpenSSL before 0.9.5a the first certificate whose
255 subject name matched the issuer of the current certificate was assumed to be
256 the issuers certificate. In OpenSSL 0.9.6 and later all certificates
257 whose subject name matches the issuer name of the current certificate are
258 subject to further tests. The relevant authority key identifier components
259 of the current certificate (if present) must match the subject key identifier
260 (if present) and issuer and serial number of the candidate issuer, in addition
261 the keyUsage extension of the candidate issuer (if present) must permit
264 The lookup first looks in the list of untrusted certificates and if no match
265 is found the remaining lookups are from the trusted certificates. The root CA
266 is always looked up in the trusted certificate list: if the certificate to
267 verify is a root certificate then an exact match must be found in the trusted
270 The second operation is to check every untrusted certificate's extensions for
271 consistency with the supplied purpose. If the B<-purpose> option is not included
272 then no checks are done. The supplied or "leaf" certificate must have extensions
273 compatible with the supplied purpose and all other certificates must also be valid
274 CA certificates. The precise extensions required are described in more detail in
275 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
277 The third operation is to check the trust settings on the root CA. The root
278 CA should be trusted for the supplied purpose. For compatibility with previous
279 versions of SSLeay and OpenSSL a certificate with no trust settings is considered
280 to be valid for all purposes.
282 The final operation is to check the validity of the certificate chain. The validity
283 period is checked against the current system time and the notBefore and notAfter
284 dates in the certificate. The certificate signatures are also checked at this
287 If all operations complete successfully then certificate is considered valid. If
288 any operation fails then the certificate is not valid.
292 When a verify operation fails the output messages can be somewhat cryptic. The
293 general form of the error message is:
295 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
296 error 24 at 1 depth lookup:invalid CA certificate
298 The first line contains the name of the certificate being verified followed by
299 the subject name of the certificate. The second line contains the error number
300 and the depth. The depth is number of the certificate being verified when a
301 problem was detected starting with zero for the certificate being verified itself
302 then 1 for the CA that signed the certificate and so on. Finally a text version
303 of the error number is presented.
305 An exhaustive list of the error codes and messages is shown below, this also
306 includes the name of the error code as defined in the header file x509_vfy.h
307 Some of the error codes are defined but never returned: these are described
312 =item B<0 X509_V_OK: ok>
314 the operation was successful.
316 =item B<2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate>
318 the issuer certificate of a looked up certificate could not be found. This
319 normally means the list of trusted certificates is not complete.
321 =item B<3 X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL>
323 the CRL of a certificate could not be found.
325 =item B<4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt certificate's signature>
327 the certificate signature could not be decrypted. This means that the actual signature value
328 could not be determined rather than it not matching the expected value, this is only
329 meaningful for RSA keys.
331 =item B<5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's signature>
333 the CRL signature could not be decrypted: this means that the actual signature value
334 could not be determined rather than it not matching the expected value. Unused.
336 =item B<6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer public key>
338 the public key in the certificate SubjectPublicKeyInfo could not be read.
340 =item B<7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure>
342 the signature of the certificate is invalid.
344 =item B<8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure>
346 the signature of the certificate is invalid.
348 =item B<9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid>
350 the certificate is not yet valid: the notBefore date is after the current time.
352 =item B<10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired>
354 the certificate has expired: that is the notAfter date is before the current time.
356 =item B<11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid>
358 the CRL is not yet valid.
360 =item B<12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired>
364 =item B<13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field>
366 the certificate notBefore field contains an invalid time.
368 =item B<14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field>
370 the certificate notAfter field contains an invalid time.
372 =item B<15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field>
374 the CRL lastUpdate field contains an invalid time.
376 =item B<16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field>
378 the CRL nextUpdate field contains an invalid time.
380 =item B<17 X509_V_ERR_OUT_OF_MEM: out of memory>
382 an error occurred trying to allocate memory. This should never happen.
384 =item B<18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate>
386 the passed certificate is self signed and the same certificate cannot be found in the list of
387 trusted certificates.
389 =item B<19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in certificate chain>
391 the certificate chain could be built up using the untrusted certificates but the root could not
394 =item B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate>
396 the issuer certificate could not be found: this occurs if the issuer
397 certificate of an untrusted certificate cannot be found.
399 =item B<21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first certificate>
401 no signatures could be verified because the chain contains only one certificate and it is not
404 =item B<22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long>
406 the certificate chain length is greater than the supplied maximum depth. Unused.
408 =item B<23 X509_V_ERR_CERT_REVOKED: certificate revoked>
410 the certificate has been revoked.
412 =item B<24 X509_V_ERR_INVALID_CA: invalid CA certificate>
414 a CA certificate is invalid. Either it is not a CA or its extensions are not consistent
415 with the supplied purpose.
417 =item B<25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded>
419 the basicConstraints pathlength parameter has been exceeded.
421 =item B<26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose>
423 the supplied certificate cannot be used for the specified purpose.
425 =item B<27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted>
427 the root CA is not marked as trusted for the specified purpose.
429 =item B<28 X509_V_ERR_CERT_REJECTED: certificate rejected>
431 the root CA is marked to reject the specified purpose.
433 =item B<29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch>
435 the current candidate issuer certificate was rejected because its subject name
436 did not match the issuer name of the current certificate. Only displayed when
437 the B<-issuer_checks> option is set.
439 =item B<30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier mismatch>
441 the current candidate issuer certificate was rejected because its subject key
442 identifier was present and did not match the authority key identifier current
443 certificate. Only displayed when the B<-issuer_checks> option is set.
445 =item B<31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial number mismatch>
447 the current candidate issuer certificate was rejected because its issuer name
448 and serial number was present and did not match the authority key identifier
449 of the current certificate. Only displayed when the B<-issuer_checks> option is set.
451 =item B<32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate signing>
453 the current candidate issuer certificate was rejected because its keyUsage extension
454 does not permit certificate signing.
456 =item B<50 X509_V_ERR_APPLICATION_VERIFICATION: application verification failure>
458 an application specific error. Unused.
464 Although the issuer checks are a considerable improvement over the old technique they still
465 suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that
466 trusted certificates with matching subject name must either appear in a file (as specified by the
467 B<-CAfile> option) or a directory (as specified by B<-CApath>). If they occur in both then only
468 the certificates in the file will be recognised.
470 Previous versions of OpenSSL assume certificates with matching subject name are identical and
473 Previous versions of this documentation swapped the meaning of the
474 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
475 B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
483 The -no_alt_chains options was first added to OpenSSL 1.1.0.