Port's license text
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 <perl-ldap@perl.org> 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)
SPDX canonical text (GPL-1.0-or-later)
GNU GENERAL PUBLIC LICENSE
Version 1, February 1989
Copyright (C) 1989 Free Software Foundation, Inc. 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
Preamble
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GNU GENERAL PUBLIC LICENSE TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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Appendix: How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest possible use to humanity, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.
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That's all there is to it!