5 verify - Utility to verify certificates.
10 [B<-CApath directory>]
30 [B<-attime timestamp>]
36 [B<-verify_depth num>]
37 [B<-verify_email email>]
38 [B<-verify_hostname hostname>]
40 [B<-verify_name name>]
47 The B<verify> command verifies certificate chains.
49 =head1 COMMAND OPTIONS
53 =item B<-CApath directory>
55 A directory of trusted certificates. The certificates should have names
56 of the form: hash.0 or have symbolic links to them of this
57 form ("hash" is the hashed certificate subject name: see the B<-hash> option
58 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
59 create symbolic links to a directory of certificates.
63 A file of trusted certificates. The file should contain multiple certificates
64 in PEM format concatenated together.
66 =item B<-untrusted file>
68 A file of untrusted certificates. The file should contain multiple certificates
69 in PEM format concatenated together.
71 =item B<-trusted_first>
73 Use certificates in CA file or CA directory before certificates in untrusted
74 file when building the trust chain to verify certificates.
75 This is mainly useful in environments with Bridge CA or Cross-Certified CAs.
77 =item B<-purpose purpose>
79 The intended use for the certificate. If this option is not specified,
80 B<verify> will not consider certificate purpose during chain verification.
81 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
82 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
87 Print out a usage message.
91 Print extra information about the operations being performed.
93 =item B<-issuer_checks>
95 Print out diagnostics relating to searches for the issuer certificate of the
96 current certificate. This shows why each candidate issuer certificate was
97 rejected. The presence of rejection messages does not itself imply that
98 anything is wrong; during the normal verification process, several
99 rejections may take place.
101 =item B<-attime timestamp>
103 Perform validation checks using time specified by B<timestamp> and not
104 current system time. B<timestamp> is the number of seconds since
105 01.01.1970 (UNIX time).
109 Enable policy processing and add B<arg> to the user-initial-policy-set (see
110 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
111 This argument can appear more than once.
113 =item B<-policy_check>
115 Enables certificate policy processing.
117 =item B<-explicit_policy>
119 Set policy variable require-explicit-policy (see RFC5280).
121 =item B<-inhibit_any>
123 Set policy variable inhibit-any-policy (see RFC5280).
125 =item B<-inhibit_map>
127 Set policy variable inhibit-policy-mapping (see RFC5280).
129 =item B<-policy_print>
131 Print out diagnostics related to policy processing.
135 Checks end entity certificate validity by attempting to look up a valid CRL.
136 If a valid CRL cannot be found an error occurs.
138 =item B<-crl_check_all>
140 Checks the validity of B<all> certificates in the chain by attempting
141 to look up valid CRLs.
143 =item B<-ignore_critical>
145 Normally if an unhandled critical extension is present which is not
146 supported by OpenSSL the certificate is rejected (as required by RFC5280).
147 If this option is set critical extensions are ignored.
149 =item B<-x509_strict>
151 For strict X.509 compliance, disable non-compliant workarounds for broken
154 =item B<-extended_crl>
156 Enable extended CRL features such as indirect CRLs and alternate CRL
161 Enable support for delta CRLs.
163 =item B<-check_ss_sig>
165 Verify the signature on the self-signed root CA. This is disabled by default
166 because it doesn't add any security.
168 =item B<-partial_chain>
170 Allow partial certificate chain if at least one certificate is in trusted store.
172 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
174 enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
175 192 bit, or only 192 bit Level of Security respectively.
176 See RFC6460 for details. In particular the supported signature algorithms are
177 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
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 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.
207 Indicates the last option. All arguments following this are assumed to be
208 certificate files. This is useful if the first certificate filename begins
211 =item B<certificates>
213 One or more certificates to verify. If no certificates are given, B<verify>
214 will attempt to read a certificate from standard input. Certificates must be
219 =head1 VERIFY OPERATION
221 The B<verify> program uses the same functions as the internal SSL and S/MIME
222 verification, therefore this description applies to these verify operations
225 There is one crucial difference between the verify operations performed
226 by the B<verify> program: wherever possible an attempt is made to continue
227 after an error whereas normally the verify operation would halt on the
228 first error. This allows all the problems with a certificate chain to be
231 The verify operation consists of a number of separate steps.
233 Firstly a certificate chain is built up starting from the supplied certificate
234 and ending in the root CA. It is an error if the whole chain cannot be built
235 up. The chain is built up by looking up the issuers certificate of the current
236 certificate. If a certificate is found which is its own issuer it is assumed
239 The process of 'looking up the issuers certificate' itself involves a number
240 of steps. In versions of OpenSSL before 0.9.5a the first certificate whose
241 subject name matched the issuer of the current certificate was assumed to be
242 the issuers certificate. In OpenSSL 0.9.6 and later all certificates
243 whose subject name matches the issuer name of the current certificate are
244 subject to further tests. The relevant authority key identifier components
245 of the current certificate (if present) must match the subject key identifier
246 (if present) and issuer and serial number of the candidate issuer, in addition
247 the keyUsage extension of the candidate issuer (if present) must permit
250 The lookup first looks in the list of untrusted certificates and if no match
251 is found the remaining lookups are from the trusted certificates. The root CA
252 is always looked up in the trusted certificate list: if the certificate to
253 verify is a root certificate then an exact match must be found in the trusted
256 The second operation is to check every untrusted certificate's extensions for
257 consistency with the supplied purpose. If the B<-purpose> option is not included
258 then no checks are done. The supplied or "leaf" certificate must have extensions
259 compatible with the supplied purpose and all other certificates must also be valid
260 CA certificates. The precise extensions required are described in more detail in
261 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
263 The third operation is to check the trust settings on the root CA. The root
264 CA should be trusted for the supplied purpose. For compatibility with previous
265 versions of SSLeay and OpenSSL a certificate with no trust settings is considered
266 to be valid for all purposes.
268 The final operation is to check the validity of the certificate chain. The validity
269 period is checked against the current system time and the notBefore and notAfter
270 dates in the certificate. The certificate signatures are also checked at this
273 If all operations complete successfully then certificate is considered valid. If
274 any operation fails then the certificate is not valid.
278 When a verify operation fails the output messages can be somewhat cryptic. The
279 general form of the error message is:
281 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
282 error 24 at 1 depth lookup:invalid CA certificate
284 The first line contains the name of the certificate being verified followed by
285 the subject name of the certificate. The second line contains the error number
286 and the depth. The depth is number of the certificate being verified when a
287 problem was detected starting with zero for the certificate being verified itself
288 then 1 for the CA that signed the certificate and so on. Finally a text version
289 of the error number is presented.
291 An exhaustive list of the error codes and messages is shown below, this also
292 includes the name of the error code as defined in the header file x509_vfy.h
293 Some of the error codes are defined but never returned: these are described
298 =item B<0 X509_V_OK: ok>
300 the operation was successful.
302 =item B<2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate>
304 the issuer certificate of a looked up certificate could not be found. This
305 normally means the list of trusted certificates is not complete.
307 =item B<3 X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL>
309 the CRL of a certificate could not be found.
311 =item B<4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt certificate's signature>
313 the certificate signature could not be decrypted. This means that the actual signature value
314 could not be determined rather than it not matching the expected value, this is only
315 meaningful for RSA keys.
317 =item B<5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's signature>
319 the CRL signature could not be decrypted: this means that the actual signature value
320 could not be determined rather than it not matching the expected value. Unused.
322 =item B<6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer public key>
324 the public key in the certificate SubjectPublicKeyInfo could not be read.
326 =item B<7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure>
328 the signature of the certificate is invalid.
330 =item B<8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure>
332 the signature of the certificate is invalid.
334 =item B<9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid>
336 the certificate is not yet valid: the notBefore date is after the current time.
338 =item B<10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired>
340 the certificate has expired: that is the notAfter date is before the current time.
342 =item B<11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid>
344 the CRL is not yet valid.
346 =item B<12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired>
350 =item B<13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field>
352 the certificate notBefore field contains an invalid time.
354 =item B<14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field>
356 the certificate notAfter field contains an invalid time.
358 =item B<15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field>
360 the CRL lastUpdate field contains an invalid time.
362 =item B<16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field>
364 the CRL nextUpdate field contains an invalid time.
366 =item B<17 X509_V_ERR_OUT_OF_MEM: out of memory>
368 an error occurred trying to allocate memory. This should never happen.
370 =item B<18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate>
372 the passed certificate is self signed and the same certificate cannot be found in the list of
373 trusted certificates.
375 =item B<19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in certificate chain>
377 the certificate chain could be built up using the untrusted certificates but the root could not
380 =item B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate>
382 the issuer certificate could not be found: this occurs if the issuer
383 certificate of an untrusted certificate cannot be found.
385 =item B<21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first certificate>
387 no signatures could be verified because the chain contains only one certificate and it is not
390 =item B<22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long>
392 the certificate chain length is greater than the supplied maximum depth. Unused.
394 =item B<23 X509_V_ERR_CERT_REVOKED: certificate revoked>
396 the certificate has been revoked.
398 =item B<24 X509_V_ERR_INVALID_CA: invalid CA certificate>
400 a CA certificate is invalid. Either it is not a CA or its extensions are not consistent
401 with the supplied purpose.
403 =item B<25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded>
405 the basicConstraints pathlength parameter has been exceeded.
407 =item B<26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose>
409 the supplied certificate cannot be used for the specified purpose.
411 =item B<27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted>
413 the root CA is not marked as trusted for the specified purpose.
415 =item B<28 X509_V_ERR_CERT_REJECTED: certificate rejected>
417 the root CA is marked to reject the specified purpose.
419 =item B<29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch>
421 the current candidate issuer certificate was rejected because its subject name
422 did not match the issuer name of the current certificate. Only displayed when
423 the B<-issuer_checks> option is set.
425 =item B<30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier mismatch>
427 the current candidate issuer certificate was rejected because its subject key
428 identifier was present and did not match the authority key identifier current
429 certificate. Only displayed when the B<-issuer_checks> option is set.
431 =item B<31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial number mismatch>
433 the current candidate issuer certificate was rejected because its issuer name
434 and serial number was present and did not match the authority key identifier
435 of the current certificate. Only displayed when the B<-issuer_checks> option is set.
437 =item B<32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate signing>
439 the current candidate issuer certificate was rejected because its keyUsage extension
440 does not permit certificate signing.
442 =item B<50 X509_V_ERR_APPLICATION_VERIFICATION: application verification failure>
444 an application specific error. Unused.
450 Although the issuer checks are a considerable improvement over the old technique they still
451 suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that
452 trusted certificates with matching subject name must either appear in a file (as specified by the
453 B<-CAfile> option) or a directory (as specified by B<-CApath>. If they occur in both then only
454 the certificates in the file will be recognised.
456 Previous versions of OpenSSL assume certificates with matching subject name are identical and
459 Previous versions of this documentation swapped the meaning of the
460 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
461 B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.