5 verify - Utility to verify certificates.
11 [B<-CApath directory>]
12 [B<-attime timestamp>]
36 [B<-verify_depth num>]
37 [B<-verify_email email>]
38 [B<-verify_hostname hostname>]
40 [B<-verify_name name>]
48 The B<verify> command verifies certificate chains.
50 =head1 COMMAND OPTIONS
56 A file of trusted certificates. The file should contain multiple certificates
57 in PEM format concatenated together.
59 =item B<-CApath directory>
61 A directory of trusted certificates. The certificates should have names
62 of the form: hash.0 or have symbolic links to them of this
63 form ("hash" is the hashed certificate subject name: see the B<-hash> option
64 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
65 create symbolic links to a directory of certificates.
67 =item B<-attime timestamp>
69 Perform validation checks using time specified by B<timestamp> and not
70 current system time. B<timestamp> is the number of seconds since
71 01.01.1970 (UNIX time).
73 =item B<-check_ss_sig>
75 Verify the signature on the self-signed root CA. This is disabled by default
76 because it doesn't add any security.
78 =item B<-crlfile file>
80 File containing one or more CRL's (in PEM format) to load.
84 Checks end entity certificate validity by attempting to look up a valid CRL.
85 If a valid CRL cannot be found an error occurs.
87 =item B<-crl_check_all>
89 Checks the validity of B<all> certificates in the chain by attempting
90 to look up valid CRLs.
92 =item B<-explicit_policy>
94 Set policy variable require-explicit-policy (see RFC5280).
96 =item B<-extended_crl>
98 Enable extended CRL features such as indirect CRLs and alternate CRL
103 Print out a usage message.
105 =item B<-ignore_critical>
107 Normally if an unhandled critical extension is present which is not
108 supported by OpenSSL the certificate is rejected (as required by RFC5280).
109 If this option is set critical extensions are ignored.
111 =item B<-inhibit_any>
113 Set policy variable inhibit-any-policy (see RFC5280).
115 =item B<-inhibit_map>
117 Set policy variable inhibit-policy-mapping (see RFC5280).
119 =item B<-issuer_checks>
121 Print out diagnostics relating to searches for the issuer certificate of the
122 current certificate. This shows why each candidate issuer certificate was
123 rejected. The presence of rejection messages does not itself imply that
124 anything is wrong; during the normal verification process, several
125 rejections may take place.
127 =item B<-partial_chain>
129 Allow partial certificate chain if at least one certificate is in trusted store.
133 Enable policy processing and add B<arg> to the user-initial-policy-set (see
134 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
135 This argument can appear more than once.
137 =item B<-policy_check>
139 Enables certificate policy processing.
141 =item B<-policy_print>
143 Print out diagnostics related to policy processing.
145 =item B<-purpose purpose>
147 The intended use for the certificate. If this option is not specified,
148 B<verify> will not consider certificate purpose during chain verification.
149 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
150 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
153 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
155 enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
156 192 bit, or only 192 bit Level of Security respectively.
157 See RFC6460 for details. In particular the supported signature algorithms are
158 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
161 =item B<-trusted_first>
163 Use certificates in CA file or CA directory before certificates in untrusted
164 file when building the trust chain to verify certificates.
165 This is mainly useful in environments with Bridge CA or Cross-Certified CAs.
167 =item B<-untrusted file>
169 A file of untrusted certificates. The file should contain multiple certificates
170 in PEM format concatenated together.
174 Enable support for delta CRLs.
178 Print extra information about the operations being performed.
180 =item B<-verify_depth num>
182 Limit the maximum depth of the certificate chain to B<num> certificates.
184 =item B<-verify_email email>
186 Verify if the B<email> matches the email address in Subject Alternative Name or
187 the email in the subject Distinguished Name.
189 =item B<-verify_hostname hostname>
191 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
192 Common Name in the subject certificate.
194 =item B<-verify_ip ip>
196 Verify if the B<ip> matches the IP address in Subject Alternative Name of
197 the subject certificate.
199 =item B<-verify_name name>
201 Use default verification options like trust model and required certificate
202 policies identified by B<name>.
203 Supported usages include: default, pkcs7, smime_sign, ssl_client, ssl_server.
205 =item B<-x509_strict>
207 For strict X.509 compliance, disable non-compliant workarounds for broken
212 Indicates the last option. All arguments following this are assumed to be
213 certificate files. This is useful if the first certificate filename begins
216 =item B<certificates>
218 One or more certificates to verify. If no certificates are given, B<verify>
219 will attempt to read a certificate from standard input. Certificates must be
224 =head1 VERIFY OPERATION
226 The B<verify> program uses the same functions as the internal SSL and S/MIME
227 verification, therefore this description applies to these verify operations
230 There is one crucial difference between the verify operations performed
231 by the B<verify> program: wherever possible an attempt is made to continue
232 after an error whereas normally the verify operation would halt on the
233 first error. This allows all the problems with a certificate chain to be
236 The verify operation consists of a number of separate steps.
238 Firstly a certificate chain is built up starting from the supplied certificate
239 and ending in the root CA. It is an error if the whole chain cannot be built
240 up. The chain is built up by looking up the issuers certificate of the current
241 certificate. If a certificate is found which is its own issuer it is assumed
244 The process of 'looking up the issuers certificate' itself involves a number
245 of steps. In versions of OpenSSL before 0.9.5a the first certificate whose
246 subject name matched the issuer of the current certificate was assumed to be
247 the issuers certificate. In OpenSSL 0.9.6 and later all certificates
248 whose subject name matches the issuer name of the current certificate are
249 subject to further tests. The relevant authority key identifier components
250 of the current certificate (if present) must match the subject key identifier
251 (if present) and issuer and serial number of the candidate issuer, in addition
252 the keyUsage extension of the candidate issuer (if present) must permit
255 The lookup first looks in the list of untrusted certificates and if no match
256 is found the remaining lookups are from the trusted certificates. The root CA
257 is always looked up in the trusted certificate list: if the certificate to
258 verify is a root certificate then an exact match must be found in the trusted
261 The second operation is to check every untrusted certificate's extensions for
262 consistency with the supplied purpose. If the B<-purpose> option is not included
263 then no checks are done. The supplied or "leaf" certificate must have extensions
264 compatible with the supplied purpose and all other certificates must also be valid
265 CA certificates. The precise extensions required are described in more detail in
266 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
268 The third operation is to check the trust settings on the root CA. The root
269 CA should be trusted for the supplied purpose. For compatibility with previous
270 versions of SSLeay and OpenSSL a certificate with no trust settings is considered
271 to be valid for all purposes.
273 The final operation is to check the validity of the certificate chain. The validity
274 period is checked against the current system time and the notBefore and notAfter
275 dates in the certificate. The certificate signatures are also checked at this
278 If all operations complete successfully then certificate is considered valid. If
279 any operation fails then the certificate is not valid.
283 When a verify operation fails the output messages can be somewhat cryptic. The
284 general form of the error message is:
286 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
287 error 24 at 1 depth lookup:invalid CA certificate
289 The first line contains the name of the certificate being verified followed by
290 the subject name of the certificate. The second line contains the error number
291 and the depth. The depth is number of the certificate being verified when a
292 problem was detected starting with zero for the certificate being verified itself
293 then 1 for the CA that signed the certificate and so on. Finally a text version
294 of the error number is presented.
296 An exhaustive list of the error codes and messages is shown below, this also
297 includes the name of the error code as defined in the header file x509_vfy.h
298 Some of the error codes are defined but never returned: these are described
303 =item B<0 X509_V_OK: ok>
305 the operation was successful.
307 =item B<2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate>
309 the issuer certificate of a looked up certificate could not be found. This
310 normally means the list of trusted certificates is not complete.
312 =item B<3 X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL>
314 the CRL of a certificate could not be found.
316 =item B<4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt certificate's signature>
318 the certificate signature could not be decrypted. This means that the actual signature value
319 could not be determined rather than it not matching the expected value, this is only
320 meaningful for RSA keys.
322 =item B<5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's signature>
324 the CRL signature could not be decrypted: this means that the actual signature value
325 could not be determined rather than it not matching the expected value. Unused.
327 =item B<6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer public key>
329 the public key in the certificate SubjectPublicKeyInfo could not be read.
331 =item B<7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure>
333 the signature of the certificate is invalid.
335 =item B<8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure>
337 the signature of the certificate is invalid.
339 =item B<9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid>
341 the certificate is not yet valid: the notBefore date is after the current time.
343 =item B<10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired>
345 the certificate has expired: that is the notAfter date is before the current time.
347 =item B<11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid>
349 the CRL is not yet valid.
351 =item B<12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired>
355 =item B<13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field>
357 the certificate notBefore field contains an invalid time.
359 =item B<14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field>
361 the certificate notAfter field contains an invalid time.
363 =item B<15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field>
365 the CRL lastUpdate field contains an invalid time.
367 =item B<16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field>
369 the CRL nextUpdate field contains an invalid time.
371 =item B<17 X509_V_ERR_OUT_OF_MEM: out of memory>
373 an error occurred trying to allocate memory. This should never happen.
375 =item B<18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate>
377 the passed certificate is self signed and the same certificate cannot be found in the list of
378 trusted certificates.
380 =item B<19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in certificate chain>
382 the certificate chain could be built up using the untrusted certificates but the root could not
385 =item B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate>
387 the issuer certificate could not be found: this occurs if the issuer
388 certificate of an untrusted certificate cannot be found.
390 =item B<21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first certificate>
392 no signatures could be verified because the chain contains only one certificate and it is not
395 =item B<22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long>
397 the certificate chain length is greater than the supplied maximum depth. Unused.
399 =item B<23 X509_V_ERR_CERT_REVOKED: certificate revoked>
401 the certificate has been revoked.
403 =item B<24 X509_V_ERR_INVALID_CA: invalid CA certificate>
405 a CA certificate is invalid. Either it is not a CA or its extensions are not consistent
406 with the supplied purpose.
408 =item B<25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded>
410 the basicConstraints pathlength parameter has been exceeded.
412 =item B<26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose>
414 the supplied certificate cannot be used for the specified purpose.
416 =item B<27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted>
418 the root CA is not marked as trusted for the specified purpose.
420 =item B<28 X509_V_ERR_CERT_REJECTED: certificate rejected>
422 the root CA is marked to reject the specified purpose.
424 =item B<29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch>
426 the current candidate issuer certificate was rejected because its subject name
427 did not match the issuer name of the current certificate. Only displayed when
428 the B<-issuer_checks> option is set.
430 =item B<30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier mismatch>
432 the current candidate issuer certificate was rejected because its subject key
433 identifier was present and did not match the authority key identifier current
434 certificate. Only displayed when the B<-issuer_checks> option is set.
436 =item B<31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial number mismatch>
438 the current candidate issuer certificate was rejected because its issuer name
439 and serial number was present and did not match the authority key identifier
440 of the current certificate. Only displayed when the B<-issuer_checks> option is set.
442 =item B<32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate signing>
444 the current candidate issuer certificate was rejected because its keyUsage extension
445 does not permit certificate signing.
447 =item B<50 X509_V_ERR_APPLICATION_VERIFICATION: application verification failure>
449 an application specific error. Unused.
455 Although the issuer checks are a considerable improvement over the old technique they still
456 suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that
457 trusted certificates with matching subject name must either appear in a file (as specified by the
458 B<-CAfile> option) or a directory (as specified by B<-CApath>). If they occur in both then only
459 the certificates in the file will be recognised.
461 Previous versions of OpenSSL assume certificates with matching subject name are identical and
464 Previous versions of this documentation swapped the meaning of the
465 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
466 B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.