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>]
52 The B<verify> command verifies certificate chains.
54 =head1 COMMAND OPTIONS
60 A file of trusted certificates. The file should contain multiple certificates
61 in PEM format concatenated together.
63 =item B<-CApath directory>
65 A directory of trusted certificates. The certificates should have names
66 of the form: hash.0 or have symbolic links to them of this
67 form ("hash" is the hashed certificate subject name: see the B<-hash> option
68 of the B<x509> utility). Under Unix the B<c_rehash> script will automatically
69 create symbolic links to a directory of certificates.
71 =item B<-attime timestamp>
73 Perform validation checks using time specified by B<timestamp> and not
74 current system time. B<timestamp> is the number of seconds since
75 01.01.1970 (UNIX time).
77 =item B<-check_ss_sig>
79 Verify the signature on the self-signed root CA. This is disabled by default
80 because it doesn't add any security.
82 =item B<-CRLfile file>
84 File containing one or more CRL's (in PEM format) to load.
86 =item B<-crl_download>
88 Attempt to download CRL information for this certificate.
92 Checks end entity certificate validity by attempting to look up a valid CRL.
93 If a valid CRL cannot be found an error occurs.
95 =item B<-crl_check_all>
97 Checks the validity of B<all> certificates in the chain by attempting
98 to look up valid CRLs.
100 =item B<-explicit_policy>
102 Set policy variable require-explicit-policy (see RFC5280).
104 =item B<-extended_crl>
106 Enable extended CRL features such as indirect CRLs and alternate CRL
111 Print out a usage message.
113 =item B<-ignore_critical>
115 Normally if an unhandled critical extension is present which is not
116 supported by OpenSSL the certificate is rejected (as required by RFC5280).
117 If this option is set critical extensions are ignored.
119 =item B<-inhibit_any>
121 Set policy variable inhibit-any-policy (see RFC5280).
123 =item B<-inhibit_map>
125 Set policy variable inhibit-policy-mapping (see RFC5280).
127 =item B<-issuer_checks>
129 Print out diagnostics relating to searches for the issuer certificate of the
130 current certificate. This shows why each candidate issuer certificate was
131 rejected. The presence of rejection messages does not itself imply that
132 anything is wrong; during the normal verification process, several
133 rejections may take place.
135 =item B<-partial_chain>
137 Allow partial certificate chain if at least one certificate is in trusted store.
141 Enable policy processing and add B<arg> to the user-initial-policy-set (see
142 RFC5280). The policy B<arg> can be an object name an OID in numeric form.
143 This argument can appear more than once.
145 =item B<-policy_check>
147 Enables certificate policy processing.
149 =item B<-policy_print>
151 Print out diagnostics related to policy processing.
153 =item B<-purpose purpose>
155 The intended use for the certificate. If this option is not specified,
156 B<verify> will not consider certificate purpose during chain verification.
157 Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
158 B<smimesign>, B<smimeencrypt>. See the B<VERIFY OPERATION> section for more
161 =item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
163 enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
164 192 bit, or only 192 bit Level of Security respectively.
165 See RFC6460 for details. In particular the supported signature algorithms are
166 reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
169 =item B<-trusted_first>
171 Use certificates in CA file or CA directory before certificates in untrusted
172 file when building the trust chain to verify certificates.
173 This is mainly useful in environments with Bridge CA or Cross-Certified CAs.
175 =item B<-no_alt_chains>
177 When building a certificate chain, if the first certificate chain found is not
178 trusted, then OpenSSL will continue to check to see if an alternative chain can
179 be found that is trusted. With this option that behaviour is suppressed so that
180 only the first chain found is ever used. Using this option will force the
181 behaviour to match that of OpenSSL versions prior to 1.1.0.
183 =item B<-untrusted file>
185 A file of untrusted certificates. The file should contain multiple certificates
186 in PEM format concatenated together.
188 =item B<-trusted file>
190 A file of additional trusted certificates. The file should contain multiple
191 certificates in PEM format concatenated together.
195 Enable support for delta CRLs.
199 Print extra information about the operations being performed.
201 =item B<-verify_depth num>
203 Limit the maximum depth of the certificate chain to B<num> certificates.
205 =item B<-verify_email email>
207 Verify if the B<email> matches the email address in Subject Alternative Name or
208 the email in the subject Distinguished Name.
210 =item B<-verify_hostname hostname>
212 Verify if the B<hostname> matches DNS name in Subject Alternative Name or
213 Common Name in the subject certificate.
215 =item B<-verify_ip ip>
217 Verify if the B<ip> matches the IP address in Subject Alternative Name of
218 the subject certificate.
220 =item B<-verify_name name>
222 Use default verification options like trust model and required certificate
223 policies identified by B<name>.
224 Supported usages include: default, pkcs7, smime_sign, ssl_client, ssl_server.
226 =item B<-x509_strict>
228 For strict X.509 compliance, disable non-compliant workarounds for broken
233 Display information about the certificate chain that has been built (if
234 successful). Certificates in the chain that came from the untrusted list will be
235 flagged as "untrusted".
239 Indicates the last option. All arguments following this are assumed to be
240 certificate files. This is useful if the first certificate filename begins
243 =item B<certificates>
245 One or more certificates to verify. If no certificates are given, B<verify>
246 will attempt to read a certificate from standard input. Certificates must be
251 =head1 VERIFY OPERATION
253 The B<verify> program uses the same functions as the internal SSL and S/MIME
254 verification, therefore this description applies to these verify operations
257 There is one crucial difference between the verify operations performed
258 by the B<verify> program: wherever possible an attempt is made to continue
259 after an error whereas normally the verify operation would halt on the
260 first error. This allows all the problems with a certificate chain to be
263 The verify operation consists of a number of separate steps.
265 Firstly a certificate chain is built up starting from the supplied certificate
266 and ending in the root CA. It is an error if the whole chain cannot be built
267 up. The chain is built up by looking up the issuers certificate of the current
268 certificate. If a certificate is found which is its own issuer it is assumed
271 The process of 'looking up the issuers certificate' itself involves a number
272 of steps. In versions of OpenSSL before 0.9.5a the first certificate whose
273 subject name matched the issuer of the current certificate was assumed to be
274 the issuers certificate. In OpenSSL 0.9.6 and later all certificates
275 whose subject name matches the issuer name of the current certificate are
276 subject to further tests. The relevant authority key identifier components
277 of the current certificate (if present) must match the subject key identifier
278 (if present) and issuer and serial number of the candidate issuer, in addition
279 the keyUsage extension of the candidate issuer (if present) must permit
282 The lookup first looks in the list of untrusted certificates and if no match
283 is found the remaining lookups are from the trusted certificates. The root CA
284 is always looked up in the trusted certificate list: if the certificate to
285 verify is a root certificate then an exact match must be found in the trusted
288 The second operation is to check every untrusted certificate's extensions for
289 consistency with the supplied purpose. If the B<-purpose> option is not included
290 then no checks are done. The supplied or "leaf" certificate must have extensions
291 compatible with the supplied purpose and all other certificates must also be valid
292 CA certificates. The precise extensions required are described in more detail in
293 the B<CERTIFICATE EXTENSIONS> section of the B<x509> utility.
295 The third operation is to check the trust settings on the root CA. The root
296 CA should be trusted for the supplied purpose. For compatibility with previous
297 versions of SSLeay and OpenSSL a certificate with no trust settings is considered
298 to be valid for all purposes.
300 The final operation is to check the validity of the certificate chain. The validity
301 period is checked against the current system time and the notBefore and notAfter
302 dates in the certificate. The certificate signatures are also checked at this
305 If all operations complete successfully then certificate is considered valid. If
306 any operation fails then the certificate is not valid.
310 When a verify operation fails the output messages can be somewhat cryptic. The
311 general form of the error message is:
313 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
314 error 24 at 1 depth lookup:invalid CA certificate
316 The first line contains the name of the certificate being verified followed by
317 the subject name of the certificate. The second line contains the error number
318 and the depth. The depth is number of the certificate being verified when a
319 problem was detected starting with zero for the certificate being verified itself
320 then 1 for the CA that signed the certificate and so on. Finally a text version
321 of the error number is presented.
323 An exhaustive list of the error codes and messages is shown below, this also
324 includes the name of the error code as defined in the header file x509_vfy.h
325 Some of the error codes are defined but never returned: these are described
330 =item B<0 X509_V_OK: ok>
332 the operation was successful.
334 =item B<2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate>
336 the issuer certificate of a looked up certificate could not be found. This
337 normally means the list of trusted certificates is not complete.
339 =item B<3 X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL>
341 the CRL of a certificate could not be found.
343 =item B<4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt certificate's signature>
345 the certificate signature could not be decrypted. This means that the actual signature value
346 could not be determined rather than it not matching the expected value, this is only
347 meaningful for RSA keys.
349 =item B<5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's signature>
351 the CRL signature could not be decrypted: this means that the actual signature value
352 could not be determined rather than it not matching the expected value. Unused.
354 =item B<6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer public key>
356 the public key in the certificate SubjectPublicKeyInfo could not be read.
358 =item B<7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure>
360 the signature of the certificate is invalid.
362 =item B<8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure>
364 the signature of the certificate is invalid.
366 =item B<9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid>
368 the certificate is not yet valid: the notBefore date is after the current time.
370 =item B<10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired>
372 the certificate has expired: that is the notAfter date is before the current time.
374 =item B<11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid>
376 the CRL is not yet valid.
378 =item B<12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired>
382 =item B<13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field>
384 the certificate notBefore field contains an invalid time.
386 =item B<14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field>
388 the certificate notAfter field contains an invalid time.
390 =item B<15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field>
392 the CRL lastUpdate field contains an invalid time.
394 =item B<16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field>
396 the CRL nextUpdate field contains an invalid time.
398 =item B<17 X509_V_ERR_OUT_OF_MEM: out of memory>
400 an error occurred trying to allocate memory. This should never happen.
402 =item B<18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate>
404 the passed certificate is self signed and the same certificate cannot be found in the list of
405 trusted certificates.
407 =item B<19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in certificate chain>
409 the certificate chain could be built up using the untrusted certificates but the root could not
412 =item B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate>
414 the issuer certificate could not be found: this occurs if the issuer
415 certificate of an untrusted certificate cannot be found.
417 =item B<21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first certificate>
419 no signatures could be verified because the chain contains only one certificate and it is not
422 =item B<22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long>
424 the certificate chain length is greater than the supplied maximum depth. Unused.
426 =item B<23 X509_V_ERR_CERT_REVOKED: certificate revoked>
428 the certificate has been revoked.
430 =item B<24 X509_V_ERR_INVALID_CA: invalid CA certificate>
432 a CA certificate is invalid. Either it is not a CA or its extensions are not consistent
433 with the supplied purpose.
435 =item B<25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded>
437 the basicConstraints pathlength parameter has been exceeded.
439 =item B<26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose>
441 the supplied certificate cannot be used for the specified purpose.
443 =item B<27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted>
445 the root CA is not marked as trusted for the specified purpose.
447 =item B<28 X509_V_ERR_CERT_REJECTED: certificate rejected>
449 the root CA is marked to reject the specified purpose.
451 =item B<29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch>
453 the current candidate issuer certificate was rejected because its subject name
454 did not match the issuer name of the current certificate. Only displayed when
455 the B<-issuer_checks> option is set.
457 =item B<30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier mismatch>
459 the current candidate issuer certificate was rejected because its subject key
460 identifier was present and did not match the authority key identifier current
461 certificate. Only displayed when the B<-issuer_checks> option is set.
463 =item B<31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial number mismatch>
465 the current candidate issuer certificate was rejected because its issuer name
466 and serial number was present and did not match the authority key identifier
467 of the current certificate. Only displayed when the B<-issuer_checks> option is set.
469 =item B<32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate signing>
471 the current candidate issuer certificate was rejected because its keyUsage extension
472 does not permit certificate signing.
474 =item B<50 X509_V_ERR_APPLICATION_VERIFICATION: application verification failure>
476 an application specific error. Unused.
482 Although the issuer checks are a considerable improvement over the old technique they still
483 suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that
484 trusted certificates with matching subject name must either appear in a file (as specified by the
485 B<-CAfile> option) or a directory (as specified by B<-CApath>). If they occur in both then only
486 the certificates in the file will be recognised.
488 Previous versions of OpenSSL assume certificates with matching subject name are identical and
491 Previous versions of this documentation swapped the meaning of the
492 B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT> and
493 B<20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY> error codes.
501 The -show_chain option was first added to OpenSSL 1.1.0.