Provided by: libcrypt-x509-perl_0.55-1_all
NAME
Crypt::X509 - Parse a X.509 certificate
SYNOPSIS
use Crypt::X509; $decoded = Crypt::X509->new( cert => $cert ); $subject_email = $decoded->subject_email; print "do not use after: ".gmtime($decoded->not_after)." GMT\n";
REQUIRES
Convert::ASN1
DESCRIPTION
Crypt::X509 parses X.509 certificates. Methods are provided for accessing most certificate 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.
CONSTRUCTOR
new ( OPTIONS ) Creates and returns a parsed X.509 certificate 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. cert => $certificate A variable containing the DER formatted certificate to be parsed (eg. as stored in "usercertificate;binary" attribute in an LDAP-directory). use Crypt::X509; use Data::Dumper; $decoded= Crypt::X509->new(cert => $cert); print Dumper($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. $decoded= Crypt::X509->new(cert => $cert); if ($decoded->error) { warn "Error on parsing Certificate:".$decoded->error; }
DATA ACCESS METHODS
You can access all parsed data directly from the returned hash. For convenience the following methods have been implemented to give quick access to the most-used certificate attributes. version Returns the certificate's version as an integer. NOTE that version is defined as an Integer where 0 = v1, 1 = v2, and 2 = v3. version_string Returns the certificate's version as a string value. serial returns the serial number (integer or Math::BigInt Object, that gets automagic evaluated in scalar context) from the certificate $decoded= Crypt::X509->new(cert => $cert); print "Certificate has serial number:".$decoded->serial."\n"; not_before returns the GMT-timestamp of the certificate's beginning date of validity. If the Certificate holds this Entry in utcTime, it is guaranteed by the RFC to been correct. As utcTime is limited to 32-bit values (like unix-timestamps) newer certificates hold the timesamps as "generalTime"-entries. The contents of "generalTime"-entries are not well defined in the RFC and are returned by this module unmodified, if no utcTime-entry is found. $decoded= Crypt::X509->new(cert => $cert); if ($decoded->notBefore < time()) { warn "Certificate: not yet valid!"; } not_after returns the GMT-timestamp of the certificate's ending date of validity. If the Certificate holds this Entry in utcTime, it is guaranteed by the RFC to been correct. As utcTime is limited to 32-bit values (like unix-timestamps) newer certificates hold the timesamps as "generalTime"-entries. The contents of "generalTime"-entries are not well defined in the RFC and are returned by this module unmodified, if no utcTime-entry is found. $decoded= Crypt::X509->new(cert => $cert); print "Certificate expires on ".gmtime($decoded->not_after)." GMT\n"; signature Return's the certificate's signature in binary DER format. pubkey Returns the certificate's public key in binary DER format. pubkey_size Returns the certificate's public key size. pubkey_algorithm Returns the algorithm as OID string which the public key was created with. PubKeyAlg returns the subject public key encryption algorithm (e.g. 'RSA') as string. $decoded= Crypt::X509->new(cert => $cert); print "Certificate public key is encrypted with:".$decoded->PubKeyAlg."\n"; Example Output: Certificate public key is encrypted with: RSA pubkey_components If this certificate contains an RSA key, this function returns a hashref { modulus => $m, exponent => $e) from that key; each value in the hash will be an integer scalar or a Math::BigInt object. For other pubkey types, it returns undef (implementations welcome!). sig_algorithm Returns the certificate's signature algorithm as OID string $decoded= Crypt::X509->new(cert => $cert); print "Certificate signature is encrypted with:".$decoded->sig_algorithm."\n";> Example Output: Certificate signature is encrypted with: 1.2.840.113549.1.1.5 SigEncAlg returns the signature encryption algorithm (e.g. 'RSA') as string. $decoded= Crypt::X509->new(cert => $cert); print "Certificate signature is encrypted with:".$decoded->SigEncAlg."\n"; Example Output: Certificate signature is encrypted with: RSA SigHashAlg returns the signature hashing algorithm (e.g. 'SHA1') as string. $decoded= Crypt::X509->new(cert => $cert); print "Certificate signature is hashed with:".$decoded->SigHashAlg."\n"; Example Output: Certificate signature is encrypted with: SHA1 Subject returns a pointer to an array of strings containing subject nameparts of the certificate. Attributenames for the most common Attributes are translated from the OID-Numbers, unknown numbers are output verbatim. $decoded= Convert::ASN1::X509->new($cert); print "DN for this Certificate is:".join(',',@{$decoded->Subject})."\n"; SubjectRaw Returns the RDNs as list of hashes, values are stringified but OIDs are not translated. If a component contains a SET, the component will become an array of hashes on the second level. SubjectSequence Returns the subject as returned from the ASN1 parser. subject_country Returns the string value for subject'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 subject contains no country attribute. subject_locality Returns the string value for subject'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 subject contains no locality attribute. subject_state Returns the string value for subject'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 subject contains no state attribute. subject_org Returns the string value for subject'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 subject contains no organization attribute. subject_ou Returns the string value for subject's organizational unit (= the value with the OID 2.5.4.11 or in DN Syntax everything after "OU="). Only the first entry is returned. "undef" if subject contains no organization attribute. subject_cn Returns the string value for subject'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 subject contains no common name attribute. subject_email Returns the string value for subject's email address (= the value with the OID 1.2.840.113549.1.9.1 or in DN Syntax everything after "emailAddress="). Only the first entry is returned. "undef" if subject contains no email attribute. Issuer returns a pointer to an array of strings building the DN of the certificate issuer (= the DN of the CA). Attributenames for the most common Attributes are translated from the OID- Numbers, unknown numbers are output verbatim. $decoded= Crypt::X509->new($cert); print "Certificate 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. KeyUsage returns a pointer to an array of strings describing the valid Usages for this certificate. "undef" is returned, when the extension is not set in the certificate. If the extension is marked critical, this is also reported. $decoded= Crypt::X509->new(cert => $cert); print "Allowed usages for this Certificate are:\n".join("\n",@{$decoded->KeyUsage})."\n"; Example Output: Allowed usages for this Certificate are: critical digitalSignature keyEncipherment dataEncipherment ExtKeyUsage returns a pointer to an array of ExtKeyUsage strings (or OIDs for unknown OIDs) or "undef" if the extension is not filled. OIDs of the following ExtKeyUsages are known: serverAuth, clientAuth, codeSigning, emailProtection, timeStamping, OCSPSigning If the extension is marked critical, this is also reported. $decoded= Crypt::X509->new($cert); print "ExtKeyUsage extension of this Certificates is: ", join(", ", @{$decoded->ExtKeyUsage}), "\n"; Example Output: ExtKeyUsage extension of this Certificates is: critical, serverAuth SubjectAltName returns a pointer to an array of strings containing alternative Subjectnames or "undef" if the extension is not filled. Usually this Extension holds the e-Mail address for person- certificates or DNS-Names for server certificates. It also pre-pends the field type (ie rfc822Name) to the returned value. $decoded= Crypt::X509->new($cert); print "E-Mail or Hostnames in this Certificates is/are:", join(", ", @{$decoded->SubjectAltName}), "\n"; Example Output: E-Mail or Hostnames in this Certificates is/are: rfc822Name=user@server.com DecodedSubjectAltNames Returns a pointer to an array of strings containing all the alternative subject name extensions. Each such extension is represented as a decoded ASN.1 value, i.e. a pointer to a list of pointers to objects, each object having a single key with the type of the alternative name and a value specific to that type. Example return value: [ [ { 'directoryName' => { 'rdnSequence' => [ [ { 'value' => { 'utf8String' => 'example' }, 'type' => '2.5.4.3' } ] ] } }, { 'dNSName' => 'example.com' } ] ] authorityCertIssuer returns a pointer to an array of strings building the DN of the Authority Cert Issuer. Attributenames for the most common Attributes are translated from the OID-Numbers, unknown numbers are output verbatim. undef if the extension is not set in the certificate. $decoded= Crypt::X509->new($cert); print "Certificate was authorised by:".join(',',@{$decoded->authorityCertIssuer})."\n"; authority_serial Returns the authority's certificate serial number. key_identifier Returns the authority key identifier or undef if it is a rooted cert 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. CRLDistributionPoints Returns the CRL distribution points as an array of strings (with one value usually) CRLDistributionPoints2 Returns the CRL distribution points as an array of hashes (allowing for some variations) CertificatePolicies Returns the CertificatePolicies as an array of strings EntrustVersionInfo Returns the EntrustVersion as a string print "Entrust Version: ", $decoded->EntrustVersion, "\n"; Example Output: Entrust Version: V7.0 SubjectDirectoryAttributes Returns the SubjectDirectoryAttributes as an array of key = value pairs, to include a data type print "Subject Directory Attributes: ", join( ', ' , @{ $decoded->SubjectDirectoryAttributes } ), "\n"; Example Output: Subject Directory Attributes: 1.2.840.113533.7.68.29 = 7 (integer) BasicConstraints Returns the BasicConstraints as an array and the criticallity pre-pended. subject_keyidentifier Returns the subject key identifier from the extensions. SubjectInfoAccess Returns the SubjectInfoAccess as an array of hashes with key=value pairs. print "Subject Info Access: "; if ( defined $decoded->SubjectInfoAccess ) { my %SIA = $decoded->SubjectInfoAccess; for my $key ( keys %SIA ) { print "\n\t$key: \n\t"; print join( "\n\t" , @{ $SIA{$key} } ), "\n"; } } else { print "\n" } Example Output: Subject Info Access: 1.3.6.1.5.5.7.48.5: uniformResourceIdentifier = http://pki.treas.gov/root_sia.p7c uniformResourceIdentifier = ldap://ldap.treas.gov/ou=US%20Treasury%20Root%20CA,ou=Certification%20Authorities,ou=Department%20of%20the%20Treasury,o=U.S.%20Government,c=US?cACertificate;binary,crossCertificatePair;binary PGPExtension Returns the creation timestamp of the corresponding OpenPGP key. (see http://www.imc.org/ietf-openpgp/mail-archive/msg05320.html) print "PGPExtension: "; if ( defined $decoded->PGPExtension ) { my $creationtime = $decoded->PGPExtension; printf "\n\tcorresponding OpenPGP Creation Time: ", $creationtime, "\n"; } Example Output: PGPExtension: whatever
SEE ALSO
See the examples of "Convert::ASN1" and the <perl-ldap@perl.org> Mailing List. An example on how to load certificates can be found in t\Crypt-X509.t.
ACKNOWLEDGEMENTS
This module is based on the x509decode script, which was contributed to Convert::ASN1 in 2002 by Norbert Klasen.
AUTHORS
Mike Jackson <mj@sci.fi>, Alexander Jung <alexander.w.jung@gmail.com>, Duncan Segrest <duncan@gigageek.info> Oliver Welter <owelter@whiterabbitsecurity.com>
COPYRIGHT
Copyright (c) 2005 Mike Jackson <mj@sci.fi>. Copyright (c) 2001-2002 Norbert Klasen, DAASI International GmbH. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.