=pod =head1 NAME Crypt::MagicSignatures::Envelope - MagicEnvelopes for the Salmon Protocol =head1 SYNOPSIS use Crypt::MagicSignatures::Key; use Crypt::MagicSignatures::Envelope; # Generate a new MagicKey for signing messages my $mkey = Crypt::MagicSignatures::Key->generate(size => 1024); # Fold a new envelope my $me = Crypt::MagicSignatures::Envelope->new( data => 'Some arbitrary string.' ); # Sign magic envelope $me->sign($mkey); # Extract the public key my $mkey_public = $mkey->to_string; # Verify the signature of the envelope if ($me->verify($mkey_public)) { print 'Signature is verified!'; }; =head1 DESCRIPTION L<Crypt::MagicSignatures::Envelope> implements MagicEnvelopes with MagicSignatures as described in the L<MagicSignatures Specification|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html> to sign messages of the L<Salmon Protocol|http://www.salmon-protocol.org/>. MagicSignatures is a "robust mechanism for digitally signing nearly arbitrary messages". B<This module is an early release! There may be significant changes in the future.> =head1 ATTRIBUTES =head2 alg my $alg = $me->alg; The algorithm used for signing the MagicEnvelope. Defaults to C<RSA-SHA256>, which is the only supported algorithm. =head2 data my $data = $me->data; $me->data('Hello world!'); The decoded data folded in the MagicEnvelope. =head2 data_type my $data_type = $me->data_type; $me->data_type('text/plain'); The Mime type of the data folded in the MagicEnvelope. Defaults to C<text/plain>. =head2 dom # Fold an xml message my $me = Crypt::MagicSignatures::Envelope->new( data => <<'XML' ); <?xml version='1.0' encoding='UTF-8'?> <entry xmlns='http://www.w3.org/2005/Atom'> <author><uri>alice@example.com</uri></author> </entry> XML # Define an xml mime type $me->data_type('application/atom+xml'); print $me->dom->at('author > uri')->text; # alice@example.com The L<Mojo::DOM> object of the decoded data, in the case the MagicEnvelope contains XML. B<This attribute is experimental and may change without warnings!> =head2 encoding my $encoding = $me->encoding; The encoding of the MagicEnvelope. Defaults to C<base64url>, which is the only encoding supported. =head2 signature my $sig = $me->signature; my $sig = $me->signature('key-01'); A signature of the MagicEnvelope. For retrieving a specific signature, pass a key id, otherwise a default signature will be returned. If a matching signature is found, the signature is returned as a hash reference, containing base64url encoded data for C<value> and possibly a C<key_id>. If no matching signature is found, a C<false> value is returned. =head2 signature_base my $base = $me->signature_base; The L<signature base string|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#sbs> of the MagicEnvelope. =head2 signed # With key id if ($me->signed('key-01')) { print 'MagicEnvelope is signed with key-01.'; } # Without key id elsif ($me->signed) { print 'MagicEnvelope is signed.'; } else { print 'MagicEnvelope is not signed.'; }; Returns a C<true> value in case the MagicEnvelope is signed at least once. Accepts optionally a C<key_id> and returns a C<true> value, if the MagicEnvelope was signed with this specific key. =head1 METHODS =head2 new $me = Crypt::MagicSignatures::Envelope->new(<<'MEXML'); <?xml version="1.0" encoding="UTF-8"?> <me:env xmlns:me="http://salmon-protocol.org/ns/magic-env"> <me:data type="text/plain"> U29tZSBhcmJpdHJhcnkgc3RyaW5nLg== </me:data> <me:encoding>base64url</me:encoding> <me:alg>RSA-SHA256</me:alg> <me:sig key_id="my-01"> S1VqYVlIWFpuRGVTX3l4S09CcWdjRVFDYVluZkI5Ulh4dmRFSnFhQW5XUmpB UEJqZUM0b0lReER4d0IwWGVQZDhzWHAxN3oybWhpTk1vNHViNGNVOVE9PQ== </me:sig> </me:env> MEXML The constructor accepts MagicEnvelope data in various formats. It accepts MagicEnvelopes in the L<XML format|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#anchor4> or an XML document including a L<MagicEnvelope provenance|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#anchor7> element. Additionally it accepts MagicEnvelopes in the L<JSON notation|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#anchor5> or defined by the same attributes as the JSON notation (but with the data not encoded). The latter is the common way to fold new envelopes. $me = Crypt::MagicSignatures::Envelope->new(<<'MEJSON'); { "data_type": "text\/plain", "data":"U29tZSBhcmJpdHJhcnkgc3RyaW5nLg==", "alg":"RSA-SHA256", "encoding":"base64url", "sigs": [ { "key_id": "my-01", "value":"S1VqYVlIWFpuRGVTX3l4S09CcWdjRV..." } ] } MEJSON $me = Crypt::MagicSignatures::Envelope->new( data => 'Some arbitrary string.', data_type => 'text/plain', alg => 'RSA-SHA256', encoding => 'base64url', sigs => [ { key_id => 'my-01', value => 'S1VqYVlIWFpuRGVTX3l4S09CcWdjRV...' } ] ); Finally the constructor accepts MagicEnvelopes in the L<compact notation|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#compact>. $me = Crypt::MagicSignatures::Envelope->new(<<'MECOMPACT'); bXktMDE=.S1VqYVlIWFpuRGVTX3l4S09CcWdjRVFDYVlu ZkI5Ulh4dmRFSnFhQW5XUmpBUEJqZUM0b0lReER4d0IwW GVQZDhzWHAxN3oybWhpTk1vNHViNGNVOVE9PQ==.U29tZ SBhcmJpdHJhcnkgc3RyaW5nLg.dGV4dC9wbGFpbg.YmFz ZTY0dXJs.UlNBLVNIQTI1Ng MECOMPACT =head2 sign $me->sign('key-01' => 'RSA.hgfrhvb ...') ->sign('RSA.hgfrhvb ...') ->sign('RSA.hgfrhvb ...', -data) ->sign('key-02' => 'RSA.hgfrhvb ...', -data); my $mkey = Crypt::MagicSignatures::Key->new('RSA.hgfrhvb ...'); $me->sign($mkey); Adds a signature to the MagicEnvelope. For adding a signature, the private key with an optional prepended key id has to be given. The private key can be a L<Crypt::MagicSignatures::Key> object, a MagicKey in L<compact notation|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#rfc.section.8.1> or a hash reference containing the non-generation parameters accepted by the L<Crypt::MagicSignatures::Key> constructor. Optionally a flag C<-data> can be passed, that will sign the data payload instead of the L<signature base string|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#rfc.section.3.2> (this is implemented for compatibility with non-standard implementations). On success, the method returns the MagicEnvelope, otherwise it returns a C<false> value. A MagicEnvelope can be signed multiple times. B<This method is experimental and may change without warnings!> =head2 verify my $mkey = Crypt::MagicSignatures::Key->new( 'RSA.hgfrhvb ...' ); $me->verify( 'RSA.vsd...', $mkey, ['key-01' => 'RSA.hgfrhvb...', -data] ); Verifies a signed envelope against a bunch of given public MagicKeys. Returns a C<true> value on success, otherwise C<false>. If one key succeeds, the envelope is verified. An element can be a L<Crypt::MagicSignatures::Key> object, a MagicKey in L<compact notation|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#rfc.section.8.1> or a hash reference containing the non-generation parameters accepted by the L<Crypt::MagicSignatures::Key> constructor. For referring to a certain key, an array reference can be passed, containing the key (defined as described above) with an optional prepended key id and an optional flag appended, referring to the data to be verified. Conforming with the specification the default value is C<-base>, referring to the L<signature base string|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#rfc.section.3.2> of the MagicEnvelope. C<-data> will verify against the data only, C<-compatible> will first try to verify against the base signature string and then will verify against the data on failure (this is implemented for compatibility with non-standard implementations). B<This method is experimental and may change without warnings!> =head2 to_compact my $compact_string = $me->to_compact; Returns the MagicEnvelope in L<compact notation|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#compact>. =head2 to_json my $json_string = $me->to_json; Returns the MagicEnvelope as a stringified L<JSON representation|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#anchor5>. =head2 to_xml my $xml_string = $me->to_xml; my $xml_provenance_string = $me->to_xml(1); Returns the MagicEnvelope as a stringified L<xml representation|http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html#anchor4>. If a C<true> value is passed, a provenance fragment will be returned instead of a valid xml document. =head1 DEPENDENCIES L<Crypt::MagicSignatures::Key>, L<Mojolicious>. For speed improvements, see the recommendations in L<Crypt::MagicSignatures::Key|Crypt::MagicSignatures::Key/DEPENDENCIES>. =head1 KNOWN BUGS AND LIMITATIONS The signing and verification is not guaranteed to be compatible with other implementations, due to different versions of the specification. Implementations like L<StatusNet|http://status.net/> (L<Identi.ca|http://identi.ca/>), L<MiniMe|https://code.google.com/p/minime-microblogger/>, and examples from the L<reference implementation|https://code.google.com/p/salmon-protocol/source/browse/> are tested. See the test suite for further information. =head1 AVAILABILITY https://github.com/Akron/Crypt-MagicSignatures-Envelope =head1 COPYRIGHT AND LICENSE Copyright (C) 2012-2021, L<Nils Diewald|https://www.nils-diewald.de/>. This program is free software, you can redistribute it and/or modify it under the terms of the Artistic License version 2.0. =cut