Crypt-X509-CRL version 0.4 Crypt::X509::CRL is an object oriented X.509 certificate revocation list parser with numerous methods for directly extracting information from certificate revocation lists. INSTALLATION To install this module, run the following commands: perl Makefile.PL make make test make install SUPPORT AND DOCUMENTATION After installing, you can find documentation for this module with the perldoc command. perldoc Crypt::X509::CRL You can also look for information at: RT, CPAN's request tracker (report bugs here) https://rt.cpan.org/NoAuth/Bugs.html?Dist=Crypt-X509-CRL CPAN Ratings https://cpanratings.perl.org/d/Crypt-X509-CRL Search CPAN https://metacpan.org/release/Crypt-X509-CRL DEPENDENCIES This module requires: Convert::ASN1 NAME Crypt::X509::CRL - Parses an X.509 certificate revocation list SYNOPSIS use Crypt::X509::CRL; $decoded = Crypt::X509::CRL->new( crl => $crl ); $subject_email = $decoded->subject_email; print "do not use after: ".gmtime($decoded->not_after)." GMT\n"; REQUIRES Convert::ASN1 DESCRIPTION Crypt::X509::CRL parses X.509 certificate revocation lists. Methods are provided for accessing most CRL elements. It is based on the generic ASN.1 module by Graham Barr, on the x509decode example by Norbert Klasen and contributions on the perl-ldap-dev-Mailinglist by Chriss Ridd. It is also based upon the works of Mike Jackson and Alexander Jung perl module Crypt::X509. The following RFC 3280 Extensions are available (noted are the ones I have implemented). Authority Key Identifier (implemented) CRL Number (implemented) Issuing Distribution Point (implemented) Issuer Alternative Name Delta CRL Indicator Freshest CRL (a.k.a. Delta CRL Distribution Point) The following RFC 3280 CRL Entry Extensions are available (noted are the ones I have implemented). Reason Code (implemented) Hold Instruction Code (implemented) Invalidity Date (implemented) Certificate Issuer NOTE: The use of 'utcTime' in determining the revocation date of a given certificate is based on RFC 3280 for dates through the year 2049. Starting with dates in 2050 and beyond the RFC calls for revocation dates to be listed as 'generalTime'. CONSTRUCTOR new ( OPTIONS ) Creates and returns a parsed X.509 CRL hash, containing the parsed contents. The data is organised as specified in RFC 2459. By default only the first ASN.1 Layer is decoded. Nested decoding is done automagically through the data access methods. crl => $crl A variable containing the DER formatted crl to be parsed (eg. as stored in "certificateRevocationList;binary" attribute in an LDAP-directory). Example: use Crypt::X509::CRL; use Data::Dumper; $decoded = Crypt::X509::CRL->new( crl => $crl ); print Dumper $decoded; METHODS error Returns the last error from parsing, "undef" when no error occured. This error is updated on deeper parsing with the data access methods. Example: $decoded= Crypt::X509::CRL->new(crl => $crl); if ( $decoded->error ) { warn "Error on parsing Certificate Revocation List: ", $decoded->error; } DATA ACCESS METHODS You can access all parsed data directly from the returned hash. For convenience the following data access methods have been implemented to give quick access to the most-used crl attributes. version Returns the certificate revocation list's version as an integer. Returns undef if the version is not specified, since it is an optional field in some cases. NOTE that version is defined as an Integer where: 0 = v1 1 = v2 2 = v3 version_string Returns the certificate revocation list's version as a string value (ie 'v1', 'v2', or 'v3'). this_update Returns either the utcTime or generalTime of the certificate revocation list's date of publication. Returns undef if not defined. Example: $decoded = Crypt::X509::CRL->new(crl => $crl); print "CRL was published at ", gmtime( $decoded->this_update ), " GMT\n"; next_update Returns either the utcTime or generalTime of the certificate revocation list's date of expiration. Returns undef if not defined. Example: $decoded = Crypt::X509::CRL->new(crl => $crl); if ( $decoded->next_update > time() ) { warn "CRL has expired!"; } signature Return's the certificate's signature in binary DER format. signature_length Return's the length of the certificate's signature. signature_algorithm Returns the certificate's signature algorithm as an OID string. Example: $decoded = Crypt::X509::CRL->new(crl => $crl); print "CRL signature is encrypted with:", $decoded->signature_algorithm, "\n"; Example Output: CRL signature is encrypted with: 1.2.840.113549.1.1.5 SigEncAlg Returns the signature encryption algorithm (e.g. 'RSA') as a string. Example: $decoded = Crypt::X509::CRL->new(crl => $crl); print "CRL signature is encrypted with:", $decoded->SigEncAlg, "\n"; Example Output: CRL signature is encrypted with: RSA SigHashAlg Returns the signature hashing algorithm (e.g. 'SHA1') as a string. Example: $decoded = Crypt::X509::CRL->new(crl => $crl); print "CRL signature is hashed with:", $decoded->SigHashAlg, "\n"; Example Output: CRL signature is encrypted with: SHA1 Issuer Returns a pointer to an array of strings building the DN of the certificate issuer (= the DN of the CA). Attribute names for the most common Attributes are translated from the OID-Numbers, unknown numbers are output verbatim. Example: $decoded = Crypt::X509::CRL->new( $crl ); print "CRL was issued by: ", join( ', ' , @{ $decoded->Issuer } ), "\n"; issuer_cn Returns the string value for issuer's common name (= the value with the OID 2.5.4.3 or in DN Syntax everything after "CN="). Only the first entry is returned. "undef" if issuer contains no common name attribute. issuer_country Returns the string value for issuer's country (= the value with the OID 2.5.4.6 or in DN Syntax everything after "C="). Only the first entry is returned. "undef" if issuer contains no country attribute. issuer_state Returns the string value for issuer's state or province (= the value with the OID 2.5.4.8 or in DN Syntax everything after "S="). Only the first entry is returned. "undef" if issuer contains no state attribute. issuer_locality Returns the string value for issuer's locality (= the value with the OID 2.5.4.7 or in DN Syntax everything after "L="). Only the first entry is returned. "undef" if issuer contains no locality attribute. issuer_org Returns the string value for issuer's organization (= the value with the OID 2.5.4.10 or in DN Syntax everything after "O="). Only the first entry is returned. "undef" if issuer contains no organization attribute. issuer_email Returns the string value for issuer's email address (= the value with the OID 1.2.840.113549.1.9.1 or in DN Syntax everything after "E="). Only the first entry is returned. "undef" if issuer contains no email attribute. key_identifier Returns the authority key identifier as a bit string. Example: $decoded = Crypt::X509::CRL->new( $crl ); my $s = unpack("H*" , $decoded->key_identifier); print "The Authority Key Identifier in HEX is: $s\n"; Example output: The Authority Key Identifier in HEX is: 86595f93caf32da620a4f9595a4a935370e792c9 authorityCertIssuer Returns a pointer to an array of strings building the DN of the Authority Cert Issuer. Attribute names for the most common Attributes are translated from the OID-Numbers, unknown numbers are output verbatim. Returns undef if the extension is not set in the certificate. Example: $decoded = Crypt::X509::CRL->new($cert); print "Certificate was authorised by:", join( ', ', @{ $decoded->authorityCertIssuer } ), "\n"; authority_serial Returns the authority's certificate serial number. authority_cn Returns the authority's ca. authority_country Returns the authority's country. authority_state Returns the authority's state. authority_locality Returns the authority's locality. authority_org Returns the authority's organization. authority_email Returns the authority's email. crl_number Returns the CRL Number as an integer. IDPs Returns the Issuing Distribution Points as a hash providing for the default values. Example: print "Issuing Distribution Points:\n"; my $IDPs = $decoded->IDPs; for my $key ( sort keys %{ $IDPs } ) { print "$key = "; if ( defined $IDPs->{ $key } ) { print $IDPs->{ $key }, "\n"; } else { print "undef\n"; } } Example Output: Issuing Distribution Points: critical = 1 directory_addr = CN=CRL2, O=U.S. Government, C=US indirectCRL = 0 onlyAttribCerts = 0 onlyCaCerts = 0 onlyUserCerts = 1 reasonFlags = undef url = undef Example of returned data structure: critical = 0 or 1 # default is FALSE directory_addr = CN=CR1,c=US # default is undef url = ldap://ldap.gov/cn=CRL1,c=US # default is undef onlyUserCerts = 0 or 1 # default is FALSE onlyCaCerts = 0 or 1 # default is FALSE onlyAttribCerts = 0 or 1 # default is FALSE indirectCRL = 0 or 1 # default is FALSE reasonFlags = BIT STRING # default is undef revocation_list Returns an array of hashes for the revoked certificates listed on the given CRL. The keys to the hash are the certificate serial numbers in decimal format. Example: print "Revocation List:\n"; my $rls = $decoded->revocation_list; my $count_of_rls = keys %{ $rls }; print "Found $count_of_rls revoked certificate(s) on this CRL.\n"; for my $key ( sort keys %{ $rls } ) { print "Certificate: ", DecimalToHex( $key ), "\n"; for my $extn ( sort keys %{ $rls->{ $key } } ) { if ( $extn =~ /date/i ) { print "\t$extn: ", ConvertTime( $rls->{ $key }{ $extn } ), "\n"; } else { print "\t$extn: ", $rls->{ $key }{ $extn }, "\n"; } } } Example Output: Revocation List: Found 1 revoked certificate(s) on this CRL. Certificate: 44 53 a0 f3 crlReason: keyCompromise invalidityDate: Wednesday, September 27, 2006 12:54:51 PM revocationDate: Wednesday, September 27, 2006 1:29:36 PM SEE ALSO See the examples of "Convert::ASN1" and the Mailing List. An example on how to load certificates can be found in t\Crypt-X509-CRL.t. ACKNOWLEDGEMENTS This module is based on the x509decode script, which was contributed to Convert::ASN1 in 2002 by Norbert Klasen. It is also based on the Crypt::X509 perl module, which was contributed by Mike Jackson and Alexander Jung. AUTHOR Duncan Segrest LICENSE AND COPYRIGHT This software is Copyright (c) 2007 by Duncan Segrest. This is free software, licensed under: The Artistic License 2.0 (GPL Compatible)