3 # pem2openpgp: take a PEM-encoded RSA private-key on standard input, a
4 # User ID as the first argument, and generate an OpenPGP certificate
8 # Jameson Rollins <jrollins@finestructure.net>
9 # Daniel Kahn Gillmor <dkg@fifthhorseman.net>
11 # Started on: 2009-01-07 02:01:19-0500
13 # License: GPL v3 or later (we may need to adjust this given that this
14 # connects to OpenSSL via perl)
18 use Crypt::OpenSSL::RSA;
19 use Crypt::OpenSSL::Bignum;
23 ## make sure all length() and substr() calls use bytes only:
28 # FIXME: fail if there is no given user ID.
30 # make an old-style packet out of the given packet type and body.
31 # old-style (see RFC 4880 section 4.2)
36 my $len = length($body);
44 } elsif ($len < 2**16) {
47 } elsif ($len < 2**31) {
48 ## not testing against full 32 bits because i don't want to deal
49 ## with potential overflow.
53 ## what the hell do we do here?
58 return pack('C'.$lencode, 0x80 + ($type * 4) + $lenbytes, $len).
63 # takes a Crypt::OpenSSL::Bignum, returns it formatted as OpenPGP MPI
64 # (RFC 4880 section 3.2)
68 my $val = $num->to_bin();
69 my $mpilen = length($val)*8;
71 # this is a kludgy way to get the number of significant bits in the
73 my $bitsinfirstbyte = length(sprintf("%b", ord($val)));
75 $mpilen -= (8 - $bitsinfirstbyte);
77 return pack('n', $mpilen).$val;
80 # FIXME: genericize this to accept either RSA or DSA keys:
81 sub make_rsa_key_body {
83 my $timestamp = shift;
85 my ($n, $e) = $key->get_key_parameters();
88 pack('CN', 4, $timestamp).
95 # expects an RSA key (public or private) and a timestamp
98 my $timestamp = shift;
100 my $rsabody = make_rsa_key_body($key, $timestamp);
102 return Digest::SHA1::sha1_hex(pack('Cn', 0x99, length($rsabody)).$rsabody);
105 my $holdTerminator = $/;
110 my $rsa = Crypt::OpenSSL::RSA->new_private_key($buf);
112 $rsa->use_sha1_hash();
113 $rsa->use_no_padding();
115 if (! $rsa->check_key()) {
116 die "key does not check";
119 my $version = pack('C', 4);
120 # strong assertion of identity:
121 my $sigtype = pack('C', 0x13);
123 my $pubkey_algo = pack('C', 1);
125 my $hash_algo = pack('C', 2);
129 my $timestamp = 1231003584;
131 my $creation_time_packet = pack('CCN', 5, 2, $timestamp);
134 # usage: signing and certification:
136 my $usage_packet = pack('CCC', 2, 27, $flags);
140 my $expires_in = 86400*2;
141 my $expiration_packet = pack('CCN', 5, 9, $expires_in);
144 # prefer AES-256, AES-192, AES-128, CAST5, 3DES:
145 my $pref_sym_algos = pack('CCCCCCC', 6, 11, 9, 8, 7, 3, 2);
147 # prefer SHA-1, SHA-256, RIPE-MD/160
148 my $pref_hash_algos = pack('CCCCC', 4, 21, 2, 8, 3);
150 # prefer ZLIB, BZip2, ZIP
151 my $pref_zip_algos = pack('CCCCC', 4, 22, 2, 3, 1);
153 # we support the MDC feature:
154 my $features = pack('CCC', 2, 30, 1);
156 # keyserver preference: only owner modify (???):
157 my $keyserver_pref = pack('CCC', 2, 23, 0x80);
159 my $subpackets_to_be_hashed =
160 $creation_time_packet.
169 my $subpacket_octets = pack('n', length($subpackets_to_be_hashed));
171 my $sig_data_to_be_hashed =
177 $subpackets_to_be_hashed;
179 my $pubkey = make_rsa_key_body($rsa, $timestamp);
181 #open(KEYFILE, "</home/wt215/gpg-test/key-data");
182 my $key_data = make_packet(6, $pubkey);
184 # take the last 16 characters of the fingerprint as the keyid:
185 my $keyid = substr(fingerprint($rsa, $timestamp), 40 - 16, 16);
187 # the v4 signature trailer is:
189 # version number, literal 0xff, and then a 4-byte count of the
190 # signature data itself.
191 my $trailer = pack('CCN', 4, 0xff, length($sig_data_to_be_hashed));
194 pack('CN', 0xb4, length($uid)).
200 $sig_data_to_be_hashed.
203 my $data_hash = Digest::SHA1::sha1_hex($datatosign);
206 my $issuer_packet = pack('CCH16', 9, 16, $keyid);
208 my $sig = Crypt::OpenSSL::Bignum->new_from_bin($rsa->sign($datatosign));
211 $sig_data_to_be_hashed.
212 pack('n', length($issuer_packet)).
214 pack('n', hex(substr($data_hash, 0, 4))).
217 print make_packet(6, $pubkey);
218 print make_packet(13, $uid);
219 print make_packet(2, $sig_body);
221 $/ = $holdTerminator;