VERIFY 1 2008-05-09 0.9.9-dev OpenSSL

NAME

verify - Utility to verify certificates.

LIBRARY

libcrypto, -lcrypto

SYNOPSIS

ooppeennssssll vveerriiffyy [--CCAAppaatthh ddiirreeccttoorryy] [--CCAAffiillee ffiillee] [--ppuurrppoossee ppuurrppoossee] [--uunnttrruusstteedd ffiillee] [--hheellpp] [--iissssuueerr__cchheecckkss] [--vveerrbboossee] [--] [certificates]

DESCRIPTION

The vveerriiffyy command verifies certificate chains.

COMMAND OPTIONS

--CCAAppaatthh ddiirreeccttoorryy A directory of trusted certificates. The certificates should have names
of the form: hash.0 or have symbolic links to them of this form ("hash" is the hashed certificate subject name: see the --hhaasshh option of the xx550099 utility). Under Unix the cc__rreehhaasshh script will automatically create symbolic links to a directory of certificates.
--CCAAffiillee ffiillee A file of trusted certificates. The file should contain multiple certificates
in PEM format concatenated together.
--uunnttrruusstteedd ffiillee A file of untrusted certificates. The file should contain multiple certificates
--ppuurrppoossee ppuurrppoossee the intended use for the certificate. Without this option no chain verification
will be done. Currently accepted uses are ssssllcclliieenntt, ssssllsseerrvveerr, nnssssssllsseerrvveerr, ssmmiimmeessiiggnn, ssmmiimmeeeennccrryypptt. See the VVEERRIIFFYY OOPPEERRAATTIIOONN section for more information.
--hheellpp prints out a usage message.
--vveerrbboossee print extra information about the operations being performed.
--iissssuueerr__cchheecckkss print out diagnostics relating to searches for the issuer certificate
of the current certificate. This shows why each candidate issuer certificate was rejected. However the presence of rejection messages does not itself imply that anything is wrong: during the normal verify process several rejections may take place.
-- marks the last option. All arguments following this are assumed to be
certificate files. This is useful if the first certificate filename begins with a --.
cceerrttiiffiiccaatteess one or more certificates to verify. If no certificate filenames are included
then an attempt is made to read a certificate from standard input. They should all be in PEM format.

VERIFY OPERATION

The vveerriiffyy program uses the same functions as the internal SSL and S/MIME verification, therefore this description applies to these verify operations too.

There is one crucial difference between the verify operations performed by the vveerriiffyy program: wherever possible an attempt is made to continue after an error whereas normally the verify operation would halt on the first error. This allows all the problems with a certificate chain to be determined.

The verify operation consists of a number of separate steps.

Firstly a certificate chain is built up starting from the supplied certificate and ending in the root CA. It is an error if the whole chain cannot be built up. The chain is built up by looking up the issuers certificate of the current certificate. If a certificate is found which is its own issuer it is assumed to be the root CA.

The process of 'looking up the issuers certificate' itself involves a number of steps. In versions of OpenSSL before 0.9.5a the first certificate whose subject name matched the issuer of the current certificate was assumed to be the issuers certificate. In OpenSSL 0.9.6 and later all certificates whose subject name matches the issuer name of the current certificate are subject to further tests. The relevant authority key identifier components of the current certificate (if present) must match the subject key identifier (if present) and issuer and serial number of the candidate issuer, in addition the keyUsage extension of the candidate issuer (if present) must permit certificate signing.

The lookup first looks in the list of untrusted certificates and if no match is found the remaining lookups are from the trusted certificates. The root CA is always looked up in the trusted certificate list: if the certificate to verify is a root certificate then an exact match must be found in the trusted list.

The second operation is to check every untrusted certificate's extensions for consistency with the supplied purpose. If the --ppuurrppoossee option is not included then no checks are done. The supplied or "leaf" certificate must have extensions compatible with the supplied purpose and all other certificates must also be valid CA certificates. The precise extensions required are described in more detail in the CCEERRTTIIFFIICCAATTEE EEXXTTEENNSSIIOONNSS section of the xx550099 utility.

The third operation is to check the trust settings on the root CA. The root CA should be trusted for the supplied purpose. For compatibility with previous versions of SSLeay and OpenSSL a certificate with no trust settings is considered to be valid for all purposes.

The final operation is to check the validity of the certificate chain. The validity period is checked against the current system time and the notBefore and notAfter dates in the certificate. The certificate signatures are also checked at this point.

If all operations complete successfully then certificate is considered valid. If any operation fails then the certificate is not valid.

DIAGNOSTICS

When a verify operation fails the output messages can be somewhat cryptic. The general form of the error message is:


 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
 error 24 at 1 depth lookup:invalid CA certificate

The first line contains the name of the certificate being verified followed by the subject name of the certificate. The second line contains the error number and the depth. The depth is number of the certificate being verified when a problem was detected starting with zero for the certificate being verified itself then 1 for the CA that signed the certificate and so on. Finally a text version of the error number is presented.

An exhaustive list of the error codes and messages is shown below, this also includes the name of the error code as defined in the header file x509_vfy.h Some of the error codes are defined but never returned: these are described as "unused".

00 XX550099__VV__OOKK:: ookk the operation was successful.
22 XX550099__VV__EERRRR__UUNNAABBLLEE__TTOO__GGEETT__IISSSSUUEERR__CCEERRTT:: uunnaabbllee ttoo ggeett iissssuueerr cceerrttiiffiiccaattee the issuer certificate could not be found: this occurs if the issuer certificate
of an untrusted certificate cannot be found.
33 XX550099__VV__EERRRR__UUNNAABBLLEE__TTOO__GGEETT__CCRRLL:: uunnaabbllee ttoo ggeett cceerrttiiffiiccaattee CCRRLL the CRL of a certificate could not be found. Unused.
44 XX550099__VV__EERRRR__UUNNAABBLLEE__TTOO__DDEECCRRYYPPTT__CCEERRTT__SSIIGGNNAATTUURREE:: uunnaabbllee ttoo ddeeccrryypptt cceerrttiiffiiccaattee''ss ssiiggnnaattuurree the certificate signature could not be decrypted. This means that the actual signature value
could not be determined rather than it not matching the expected value, this is only meaningful for RSA keys.
55 XX550099__VV__EERRRR__UUNNAABBLLEE__TTOO__DDEECCRRYYPPTT__CCRRLL__SSIIGGNNAATTUURREE:: uunnaabbllee ttoo ddeeccrryypptt CCRRLL''ss ssiiggnnaattuurree the CRL signature could not be decrypted: this means that the actual signature value
could not be determined rather than it not matching the expected value. Unused.
66 XX550099__VV__EERRRR__UUNNAABBLLEE__TTOO__DDEECCOODDEE__IISSSSUUEERR__PPUUBBLLIICC__KKEEYY:: uunnaabbllee ttoo ddeeccooddee iissssuueerr ppuubblliicc kkeeyy the public key in the certificate SubjectPublicKeyInfo could not be read.
77 XX550099__VV__EERRRR__CCEERRTT__SSIIGGNNAATTUURREE__FFAAIILLUURREE:: cceerrttiiffiiccaattee ssiiggnnaattuurree ffaaiilluurree the signature of the certificate is invalid.
88 XX550099__VV__EERRRR__CCRRLL__SSIIGGNNAATTUURREE__FFAAIILLUURREE:: CCRRLL ssiiggnnaattuurree ffaaiilluurree the signature of the certificate is invalid. Unused.
99 XX550099__VV__EERRRR__CCEERRTT__NNOOTT__YYEETT__VVAALLIIDD:: cceerrttiiffiiccaattee iiss nnoott yyeett vvaalliidd the certificate is not yet valid: the notBefore date is after the current time.
1100 XX550099__VV__EERRRR__CCEERRTT__HHAASS__EEXXPPIIRREEDD:: cceerrttiiffiiccaattee hhaass eexxppiirreedd the certificate has expired: that is the notAfter date is before the current time.
1111 XX550099__VV__EERRRR__CCRRLL__NNOOTT__YYEETT__VVAALLIIDD:: CCRRLL iiss nnoott yyeett vvaalliidd the CRL is not yet valid. Unused.
1122 XX550099__VV__EERRRR__CCRRLL__HHAASS__EEXXPPIIRREEDD:: CCRRLL hhaass eexxppiirreedd the CRL has expired. Unused.
1133 XX550099__VV__EERRRR__EERRRROORR__IINN__CCEERRTT__NNOOTT__BBEEFFOORREE__FFIIEELLDD:: ffoorrmmaatt eerrrroorr iinn cceerrttiiffiiccaattee''ss nnoottBBeeffoorree ffiieelldd the certificate notBefore field contains an invalid time.
1144 XX550099__VV__EERRRR__EERRRROORR__IINN__CCEERRTT__NNOOTT__AAFFTTEERR__FFIIEELLDD:: ffoorrmmaatt eerrrroorr iinn cceerrttiiffiiccaattee''ss nnoottAAfftteerr ffiieelldd the certificate notAfter field contains an invalid time.
1155 XX550099__VV__EERRRR__EERRRROORR__IINN__CCRRLL__LLAASSTT__UUPPDDAATTEE__FFIIEELLDD:: ffoorrmmaatt eerrrroorr iinn CCRRLL''ss llaassttUUppddaattee ffiieelldd the CRL lastUpdate field contains an invalid time. Unused.
1166 XX550099__VV__EERRRR__EERRRROORR__IINN__CCRRLL__NNEEXXTT__UUPPDDAATTEE__FFIIEELLDD:: ffoorrmmaatt eerrrroorr iinn CCRRLL''ss nneexxttUUppddaattee ffiieelldd the CRL nextUpdate field contains an invalid time. Unused.
1177 XX550099__VV__EERRRR__OOUUTT__OOFF__MMEEMM:: oouutt ooff mmeemmoorryy an error occurred trying to allocate memory. This should never happen.
1188 XX550099__VV__EERRRR__DDEEPPTTHH__ZZEERROO__SSEELLFF__SSIIGGNNEEDD__CCEERRTT:: sseellff ssiiggnneedd cceerrttiiffiiccaattee the passed certificate is self signed and the same certificate cannot be found in the list of
trusted certificates.
1199 XX550099__VV__EERRRR__SSEELLFF__SSIIGGNNEEDD__CCEERRTT__IINN__CCHHAAIINN:: sseellff ssiiggnneedd cceerrttiiffiiccaattee iinn cceerrttiiffiiccaattee cchhaaiinn the certificate chain could be built up using the untrusted certificates but the root could not
be found locally.
2200 XX550099__VV__EERRRR__UUNNAABBLLEE__TTOO__GGEETT__IISSSSUUEERR__CCEERRTT__LLOOCCAALLLLYY:: uunnaabbllee ttoo ggeett llooccaall iissssuueerr cceerrttiiffiiccaattee the issuer certificate of a locally looked up certificate could not be found. This normally means
the list of trusted certificates is not complete.
2211 XX550099__VV__EERRRR__UUNNAABBLLEE__TTOO__VVEERRIIFFYY__LLEEAAFF__SSIIGGNNAATTUURREE:: uunnaabbllee ttoo vveerriiffyy tthhee ffiirrsstt cceerrttiiffiiccaattee no signatures could be verified because the chain contains only one certificate and it is not
self signed.
2222 XX550099__VV__EERRRR__CCEERRTT__CCHHAAIINN__TTOOOO__LLOONNGG:: cceerrttiiffiiccaattee cchhaaiinn ttoooo lloonngg the certificate chain length is greater than the supplied maximum depth. Unused.
2233 XX550099__VV__EERRRR__CCEERRTT__RREEVVOOKKEEDD:: cceerrttiiffiiccaattee rreevvookkeedd the certificate has been revoked. Unused.
2244 XX550099__VV__EERRRR__IINNVVAALLIIDD__CCAA:: iinnvvaalliidd CCAA cceerrttiiffiiccaattee a CA certificate is invalid. Either it is not a CA or its extensions are not consistent
with the supplied purpose.
2255 XX550099__VV__EERRRR__PPAATTHH__LLEENNGGTTHH__EEXXCCEEEEDDEEDD:: ppaatthh lleennggtthh ccoonnssttrraaiinntt eexxcceeeeddeedd the basicConstraints pathlength parameter has been exceeded.
2266 XX550099__VV__EERRRR__IINNVVAALLIIDD__PPUURRPPOOSSEE:: uunnssuuppppoorrtteedd cceerrttiiffiiccaattee ppuurrppoossee the supplied certificate cannot be used for the specified purpose.
2277 XX550099__VV__EERRRR__CCEERRTT__UUNNTTRRUUSSTTEEDD:: cceerrttiiffiiccaattee nnoott ttrruusstteedd the root CA is not marked as trusted for the specified purpose.
2288 XX550099__VV__EERRRR__CCEERRTT__RREEJJEECCTTEEDD:: cceerrttiiffiiccaattee rreejjeecctteedd the root CA is marked to reject the specified purpose.
2299 XX550099__VV__EERRRR__SSUUBBJJEECCTT__IISSSSUUEERR__MMIISSMMAATTCCHH:: ssuubbjjeecctt iissssuueerr mmiissmmaattcchh the current candidate issuer certificate was rejected because its subject name
did not match the issuer name of the current certificate. Only displayed when the --iissssuueerr__cchheecckkss option is set.
3300 XX550099__VV__EERRRR__AAKKIIDD__SSKKIIDD__MMIISSMMAATTCCHH:: aauutthhoorriittyy aanndd ssuubbjjeecctt kkeeyy iiddeennttiiffiieerr mmiissmmaattcchh the current candidate issuer certificate was rejected because its subject key
identifier was present and did not match the authority key identifier current certificate. Only displayed when the --iissssuueerr__cchheecckkss option is set.
3311 XX550099__VV__EERRRR__AAKKIIDD__IISSSSUUEERR__SSEERRIIAALL__MMIISSMMAATTCCHH:: aauutthhoorriittyy aanndd iissssuueerr sseerriiaall nnuummbbeerr mmiissmmaattcchh the current candidate issuer certificate was rejected because its issuer name
and serial number was present and did not match the authority key identifier of the current certificate. Only displayed when the --iissssuueerr__cchheecckkss option is set.
3322 XX550099__VV__EERRRR__KKEEYYUUSSAAGGEE__NNOO__CCEERRTTSSIIGGNN::kkeeyy uussaaggee ddooeess nnoott iinncclluuddee cceerrttiiffiiccaattee ssiiggnniinngg the current candidate issuer certificate was rejected because its keyUsage extension
does not permit certificate signing.
5500 XX550099__VV__EERRRR__AAPPPPLLIICCAATTIIOONN__VVEERRIIFFIICCAATTIIOONN:: aapppplliiccaattiioonn vveerriiffiiccaattiioonn ffaaiilluurree an application specific error. Unused.

BUGS

Although the issuer checks are a considerably improvement over the old technique they still suffer from limitations in the underlying X509_LOOKUP API. One consequence of this is that trusted certificates with matching subject name must either appear in a file (as specified by the --CCAAffiillee option) or a directory (as specified by --CCAAppaatthh. If they occur in both then only the certificates in the file will be recognised.

Previous versions of OpenSSL assume certificates with matching subject name are identical and mishandled them.

SEE ALSO

_o_p_e_n_s_s_l___x_5_0_9(1)