3 # keytrans: this is an RSA key translation utility; it is capable of
4 # transforming RSA keys (both public keys and secret keys) between
5 # several popular representations, including OpenPGP, PEM-encoded
6 # PKCS#1 DER, and OpenSSH-style public key lines.
8 # How it behaves depends on the name under which it is invoked. The
9 # two implementations currently are: pem2openpgp and openpgp2ssh.
13 # pem2openpgp: take a PEM-encoded RSA private-key on standard input, a
14 # User ID as the first argument, and generate an OpenPGP secret key
15 # and certificate from it.
17 # WARNING: the secret key material *will* appear on stdout (albeit in
18 # OpenPGP form) -- if you redirect stdout to a file, make sure the
19 # permissions on that file are appropriately locked down!
23 # pem2openpgp 'ssh://'$(hostname -f) < /etc/ssh/ssh_host_rsa_key | gpg --import
28 # openpgp2ssh: take a stream of OpenPGP packets containing public or
29 # secret key material on standard input, and a Key ID (or fingerprint)
30 # as the first argument. Find the matching key in the input stream,
31 # and emit it on stdout in an OpenSSH-compatible format. If the input
32 # key is an OpenPGP public key (either primary or subkey), the output
33 # will be an OpenSSH single-line public key. If the input key is an
34 # OpenPGP secret key, the output will be a PEM-encoded RSA key.
38 # gpg --export-secret-subkeys --export-options export-reset-subkey-passwd $KEYID | \
39 # openpgp2ssh $KEYID | ssh-add /dev/stdin
43 # Jameson Rollins <jrollins@finestructure.net>
44 # Daniel Kahn Gillmor <dkg@fifthhorseman.net>
46 # Started on: 2009-01-07 02:01:19-0500
48 # License: GPL v3 or later (we may need to adjust this given that this
49 # connects to OpenSSL via perl)
54 use Crypt::OpenSSL::RSA;
55 use Crypt::OpenSSL::Bignum;
56 use Crypt::OpenSSL::Bignum::CTX;
61 ## make sure all length() and substr() calls use bytes only:
64 my $old_format_packet_lengths = { one => 0,
70 # see RFC 4880 section 9.1 (ignoring deprecated algorithms for now)
71 my $asym_algos = { rsa => 1,
76 # see RFC 4880 section 9.2
77 my $ciphers = { plaintext => 0,
88 # see RFC 4880 section 9.3
89 my $zips = { uncompressed => 0,
95 # see RFC 4880 section 9.4
96 my $digests = { md5 => 1,
105 # see RFC 4880 section 5.2.3.21
106 my $usage_flags = { certify => 0x01,
108 encrypt_comms => 0x04,
109 encrypt_storage => 0x08,
110 encrypt => 0x0c, ## both comms and storage
111 split => 0x10, # the private key is split via secret sharing
112 authenticate => 0x20,
113 shared => 0x80, # more than one person holds the entire private key
116 # see RFC 4880 section 4.3
117 my $packet_types = { pubkey_enc_session => 1,
119 symkey_enc_session => 3,
124 compressed_data => 8,
132 symenc_w_integrity => 18,
136 # see RFC 4880 section 5.2.1
137 my $sig_types = { binary_doc => 0x00,
140 generic_certification => 0x10,
141 persona_certification => 0x11,
142 casual_certification => 0x12,
143 positive_certification => 0x13,
144 subkey_binding => 0x18,
145 primary_key_binding => 0x19,
146 key_signature => 0x1f,
147 key_revocation => 0x20,
148 subkey_revocation => 0x28,
149 certification_revocation => 0x30,
155 # see RFC 4880 section 5.2.3.23
156 my $revocation_reasons = { no_reason_specified => 0,
158 key_compromised => 2,
160 user_id_no_longer_valid => 32,
163 # see RFC 4880 section 5.2.3.1
164 my $subpacket_types = { sig_creation_time => 2,
165 sig_expiration_time => 3,
170 key_expiration_time => 9,
171 preferred_cipher => 11,
172 revocation_key => 12,
175 preferred_digest => 21,
176 preferred_compression => 22,
177 keyserver_prefs => 23,
178 preferred_keyserver => 24,
183 revocation_reason => 29,
185 signature_target => 31,
186 embedded_signature => 32,
189 # bitstring (see RFC 4880 section 5.2.3.24)
190 my $features = { mdc => 0x01
193 # bitstring (see RFC 4880 5.2.3.17)
194 my $keyserver_prefs = { nomodify => 0x80
197 ###### end lookup tables ######
199 # FIXME: if we want to be able to interpret openpgp data as well as
200 # produce it, we need to produce key/value-swapped lookup tables as well.
203 ########### Math/Utility Functions ##############
206 # see the bottom of page 44 of RFC 4880 (http://tools.ietf.org/html/rfc4880#page-44)
207 sub simple_checksum {
210 return unpack("%16C*",$bytes);
214 # calculate/print the fingerprint of an openssh-style keyblob:
219 return join(':', map({unpack("H*", $_)} split(//, Digest::MD5::md5($keyblob))));
222 # calculate the multiplicative inverse of a mod b this is euclid's
223 # extended algorithm. For more information see:
224 # http://en.wikipedia.org/wiki/Extended_Euclidean_algorithm the
225 # arguments here should be Crypt::OpenSSL::Bignum objects. $a should
226 # be the larger of the two values, and the two values should be
229 sub modular_multi_inverse {
234 my $origdivisor = $b->copy();
236 my $ctx = Crypt::OpenSSL::Bignum::CTX->new();
237 my $x = Crypt::OpenSSL::Bignum->zero();
238 my $y = Crypt::OpenSSL::Bignum->one();
239 my $lastx = Crypt::OpenSSL::Bignum->one();
240 my $lasty = Crypt::OpenSSL::Bignum->zero();
245 while (! $b->is_zero()) {
246 my ($quotient, $remainder) = $a->div($b, $ctx);
252 $x = $lastx->sub($quotient->mul($x, $ctx));
256 $y = $lasty->sub($quotient->mul($y, $ctx));
261 die "did this math wrong.\n";
264 # let's make sure that we return a positive value because RFC 4880,
265 # section 3.2 only allows unsigned values:
267 ($finalquotient, $finalremainder) = $lastx->add($origdivisor)->div($origdivisor, $ctx);
269 return $finalremainder;
273 ############ OpenPGP formatting functions ############
275 # make an old-style packet out of the given packet type and body.
276 # old-style (see RFC 4880 section 4.2)
282 my $len = length($body);
283 my $pseudolen = $len;
285 # if the caller wants to use at least N octets of packet length,
286 # pretend that we're using that many.
287 if (defined $options && defined $options->{'packet_length'}) {
288 $pseudolen = 2**($options->{'packet_length'} * 8) - 1;
290 if ($pseudolen < $len) {
297 if ($pseudolen < 2**8) {
298 $lenbytes = $old_format_packet_lengths->{one};
300 } elsif ($pseudolen < 2**16) {
301 $lenbytes = $old_format_packet_lengths->{two};
303 } elsif ($pseudolen < 2**31) {
304 ## not testing against full 32 bits because i don't want to deal
305 ## with potential overflow.
306 $lenbytes = $old_format_packet_lengths->{four};
309 ## what the hell do we do here?
310 $lenbytes = $old_format_packet_lengths->{indeterminate};
314 return pack('C'.$lencode, 0x80 + ($type * 4) + $lenbytes, $len).
319 # takes a Crypt::OpenSSL::Bignum, returns it formatted as OpenPGP MPI
320 # (RFC 4880 section 3.2)
324 my $val = $num->to_bin();
325 my $mpilen = length($val)*8;
327 # this is a kludgy way to get the number of significant bits in the
329 my $bitsinfirstbyte = length(sprintf("%b", ord($val)));
331 $mpilen -= (8 - $bitsinfirstbyte);
333 return pack('n', $mpilen).$val;
336 # takes a Crypt::OpenSSL::Bignum, returns an MPI packed in preparation
337 # for an OpenSSH-style public key format. see:
338 # http://marc.info/?l=openssh-unix-dev&m=121866301718839&w=2
339 sub openssh_mpi_pack {
342 my $val = $num->to_bin();
343 my $mpilen = length($val);
345 my $ret = pack('N', $mpilen);
347 # if the first bit of the leading byte is high, we should include a
349 if (ord($val) & 0x80) {
350 $ret = pack('NC', $mpilen+1, 0);
356 sub openssh_pubkey_pack {
359 my ($modulus, $exponent) = $key->get_key_parameters();
361 return openssh_mpi_pack(Crypt::OpenSSL::Bignum->new_from_bin("ssh-rsa")).
362 openssh_mpi_pack($exponent).
363 openssh_mpi_pack($modulus);
366 # pull an OpenPGP-specified MPI off of a given stream, returning it as
367 # a Crypt::OpenSSL::Bignum.
370 my $readtally = shift;
373 read($instr, $bitlen, 2) or die "could not read MPI length.\n";
374 $bitlen = unpack('n', $bitlen);
377 my $bytestoread = POSIX::floor(($bitlen + 7)/8);
379 read($instr, $ret, $bytestoread) or die "could not read MPI body.\n";
380 $$readtally += $bytestoread;
381 return Crypt::OpenSSL::Bignum->new_from_bin($ret);
385 # FIXME: genericize these to accept either RSA or DSA keys:
386 sub make_rsa_pub_key_body {
388 my $key_timestamp = shift;
390 my ($n, $e) = $key->get_key_parameters();
393 pack('CN', 4, $key_timestamp).
394 pack('C', $asym_algos->{rsa}).
399 sub make_rsa_sec_key_body {
401 my $key_timestamp = shift;
403 # we're not using $a and $b, but we need them to get to $c.
404 my ($n, $e, $d, $p, $q) = $key->get_key_parameters();
406 my $c3 = modular_multi_inverse($p, $q);
408 my $secret_material = mpi_pack($d).
413 # according to Crypt::OpenSSL::RSA, the closest value we can get out
414 # of get_key_parameters is 1/q mod p; but according to sec 5.5.3 of
415 # RFC 4880, we're actually looking for u, the multiplicative inverse
416 # of p, mod q. This is why we're calculating the value directly
417 # with modular_multi_inverse.
420 pack('CN', 4, $key_timestamp).
421 pack('C', $asym_algos->{rsa}).
424 pack('C', 0). # seckey material is not encrypted -- see RFC 4880 sec 5.5.3
426 pack('n', simple_checksum($secret_material));
429 # expects an RSA key (public or private) and a timestamp
432 my $key_timestamp = shift;
434 my $rsabody = make_rsa_pub_key_body($key, $key_timestamp);
436 return Digest::SHA::sha1(pack('Cn', 0x99, length($rsabody)).$rsabody);
440 # FIXME: handle DSA keys as well!
446 # strong assertion of identity is the default (for a self-sig):
447 if (! defined $args->{certification_type}) {
448 $args->{certification_type} = $sig_types->{positive_certification};
451 if (! defined $args->{sig_timestamp}) {
452 $args->{sig_timestamp} = time();
454 my $key_timestamp = $args->{key_timestamp} + 0;
456 # generate and aggregate subpackets:
460 if (! defined $args->{usage_flags}) {
461 $flags = $usage_flags->{certify};
463 my @ff = split(",", $args->{usage_flags});
464 foreach my $f (@ff) {
465 if (! defined $usage_flags->{$f}) {
466 die "No such flag $f";
468 $flags |= $usage_flags->{$f};
471 my $usage_subpacket = pack('CCC', 2, $subpacket_types->{usage_flags}, $flags);
473 # how should we determine how far off to set the expiration date?
474 # default is no expiration. Specify the timestamp in seconds from the
476 my $expiration_subpacket = '';
477 if (defined $args->{expiration}) {
478 my $expires_in = $args->{expiration} + 0;
479 $expiration_subpacket = pack('CCN', 5, $subpacket_types->{key_expiration_time}, $expires_in);
483 # prefer AES-256, AES-192, AES-128, CAST5, 3DES:
484 my $pref_sym_algos = pack('CCCCCCC', 6, $subpacket_types->{preferred_cipher},
489 $ciphers->{tripledes}
492 # prefer SHA-512, SHA-384, SHA-256, SHA-224, RIPE-MD/160, SHA-1
493 my $pref_hash_algos = pack('CCCCCCCC', 7, $subpacket_types->{preferred_digest},
498 $digests->{ripemd160},
502 # prefer ZLIB, BZip2, ZIP
503 my $pref_zip_algos = pack('CCCCC', 4, $subpacket_types->{preferred_compression},
509 # we support the MDC feature:
510 my $feature_subpacket = pack('CCC', 2, $subpacket_types->{features},
513 # keyserver preference: only owner modify (???):
514 my $keyserver_pref = pack('CCC', 2, $subpacket_types->{keyserver_prefs},
515 $keyserver_prefs->{nomodify});
518 $args->{hashed_subpackets} =
520 $expiration_subpacket.
527 return gensig($rsa, $uid, $args);
530 # FIXME: handle non-RSA keys
532 # FIXME: this currently only makes self-sigs -- we should parameterize
533 # it to make certifications over keys other than the issuer.
539 # FIXME: allow signature creation using digests other than SHA256
540 $rsa->use_sha256_hash();
542 # see page 22 of RFC 4880 for why i think this is the right padding
544 $rsa->use_pkcs1_padding();
546 if (! $rsa->check_key()) {
547 die "key does not check\n";
550 my $certtype = $args->{certification_type} + 0;
552 my $version = pack('C', 4);
553 my $sigtype = pack('C', $certtype);
555 my $pubkey_algo = pack('C', $asym_algos->{rsa});
556 # SHA256 FIXME: allow signature creation using digests other than SHA256
557 my $hash_algo = pack('C', $digests->{sha256});
559 # FIXME: i'm worried about generating a bazillion new OpenPGP
560 # certificates from the same key, which could easily happen if you run
561 # this script more than once against the same key (because the
562 # timestamps will differ). How can we prevent this?
564 # this argument (if set) overrides the current time, to
565 # be able to create a standard key. If we read the key from a file
566 # instead of stdin, should we use the creation time on the file?
567 my $sig_timestamp = ($args->{sig_timestamp} + 0);
568 my $key_timestamp = ($args->{key_timestamp} + 0);
570 if ($key_timestamp > $sig_timestamp) {
571 die "key timestamp must not be later than signature timestamp\n";
574 my $creation_time_packet = pack('CCN', 5, $subpacket_types->{sig_creation_time}, $sig_timestamp);
576 my $hashed_subs = $creation_time_packet.$args->{hashed_subpackets};
578 my $subpacket_octets = pack('n', length($hashed_subs));
580 my $sig_data_to_be_hashed =
588 my $pubkey = make_rsa_pub_key_body($rsa, $key_timestamp);
590 # this is for signing. it needs to be an old-style header with a
591 # 2-packet octet count.
593 my $key_data = make_packet($packet_types->{pubkey}, $pubkey, {'packet_length'=>2});
595 # take the last 8 bytes of the fingerprint as the keyid:
596 my $keyid = substr(fingerprint($rsa, $key_timestamp), 20 - 8, 8);
598 # the v4 signature trailer is:
600 # version number, literal 0xff, and then a 4-byte count of the
601 # signature data itself.
602 my $trailer = pack('CCN', 4, 0xff, length($sig_data_to_be_hashed));
605 pack('CN', 0xb4, length($uid)).
611 $sig_data_to_be_hashed.
614 # FIXME: handle signatures over digests other than SHA256:
615 my $data_hash = Digest::SHA::sha256_hex($datatosign);
617 my $issuer_packet = pack('CCa8', 9, $subpacket_types->{issuer}, $keyid);
619 my $sig = Crypt::OpenSSL::Bignum->new_from_bin($rsa->sign($datatosign));
622 $sig_data_to_be_hashed.
623 pack('n', length($issuer_packet)).
625 pack('n', hex(substr($data_hash, 0, 4))).
628 return make_packet($packet_types->{sig}, $sig_body);
631 # FIXME: switch to passing the whole packet as the arg, instead of the
634 # FIXME: think about native perl representation of the packets instead.
636 # Put a user ID into the $data
641 my $packetlen = shift;
644 ($tag == $packet_types->{uid}) or die "This should not be called on anything but a User ID packet\n";
646 read($instr, $dummy, $packetlen);
647 $data->{uid}->{$dummy} = {};
648 $data->{current}->{uid} = $dummy;
652 # find signatures associated with the given fingerprint and user ID.
657 my $packetlen = shift;
659 ($tag == $packet_types->{sig}) or die "No calling findsig on anything other than a signature packet.\n";
664 read($instr, $dummy, $packetlen - $readbytes) or die "Could not read in this packet.\n";
666 if ((! defined $data->{key}) ||
667 (! defined $data->{uid}) ||
668 (! defined $data->{uid}->{$data->{target}->{uid}})) {
669 # the user ID we are looking for has not been found yet.
673 # FIXME: if we get two primary keys on stdin, both with the same
674 # targetd user ID, we'll store signatures from both keys, which is
677 # the current ID is not what we're looking for:
678 return if ($data->{current}->{uid} ne $data->{target}->{uid});
680 # just storing the raw signatures for the moment:
681 push @{$data->{sigs}}, make_packet($packet_types->{sig}, $dummy);
686 # given an input stream and data, store the found key in data and
687 # consume the rest of the stream corresponding to the packet.
688 # data contains: (fpr: fingerprint to find, key: current best guess at key)
693 my $packetlen = shift;
699 read($instr, $ver, 1) or die "could not read key version\n";
704 printf(STDERR "We only work with version 4 keys. This key appears to be version %s.\n", $ver);
705 read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
710 read($instr, $key_timestamp, 4) or die "could not read key timestamp.\n";
712 $key_timestamp = unpack('N', $key_timestamp);
715 read($instr, $algo, 1) or die "could not read key algorithm.\n";
718 if ($algo != $asym_algos->{rsa}) {
719 printf(STDERR "We only support RSA keys (this key used algorithm %d).\n", $algo);
720 read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
724 ## we have an RSA key.
725 my $modulus = read_mpi($instr, \$readbytes);
726 my $exponent = read_mpi($instr, \$readbytes);
728 my $pubkey = Crypt::OpenSSL::RSA->new_key_from_parameters($modulus, $exponent);
729 my $foundfpr = fingerprint($pubkey, $key_timestamp);
731 my $foundfprstr = Crypt::OpenSSL::Bignum->new_from_bin($foundfpr)->to_hex();
732 # left-pad with 0's to bring up to full 40-char (160-bit) fingerprint:
733 $foundfprstr = sprintf("%040s", $foundfprstr);
737 if ((!defined($data->{target}->{fpr})) ||
738 (substr($foundfprstr, -1 * length($data->{target}->{fpr})) eq $data->{target}->{fpr})) {
739 if (defined($data->{key})) {
740 die "Found two matching keys.\n";
742 $data->{key} = { 'rsa' => $pubkey,
743 'timestamp' => $key_timestamp };
747 if ($tag != $packet_types->{seckey} &&
748 $tag != $packet_types->{sec_subkey}) {
749 if ($readbytes < $packetlen) {
750 read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
755 # we don't think the public part of this key matches
756 if ($readbytes < $packetlen) {
757 read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
763 read($instr, $s2k, 1) or die "Could not read S2K octet.\n";
767 printf(STDERR "We cannot handle encrypted secret keys. Skipping!\n") ;
768 read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
772 # secret material is unencrypted
773 # see http://tools.ietf.org/html/rfc4880#section-5.5.3
774 my $d = read_mpi($instr, \$readbytes);
775 my $p = read_mpi($instr, \$readbytes);
776 my $q = read_mpi($instr, \$readbytes);
777 my $u = read_mpi($instr, \$readbytes);
780 read($instr, $checksum, 2) or die "Could not read checksum of secret key material.\n";
782 $checksum = unpack('n', $checksum);
784 # FIXME: compare with the checksum! how? the data is
785 # gone into the Crypt::OpenSSL::Bignum
787 $data->{key}->{rsa} = Crypt::OpenSSL::RSA->new_key_from_parameters($modulus,
793 $data->{key}->{rsa}->check_key() or die "Secret key is not a valid RSA key.\n";
795 if ($readbytes < $packetlen) {
796 read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
805 if (length($fpr) < 8) {
806 die "We need at least 8 hex digits of fingerprint.\n";
811 my $data = { target => { fpr => $fpr,
814 my $subs = { $packet_types->{pubkey} => \&findkey,
815 $packet_types->{pub_subkey} => \&findkey,
816 $packet_types->{seckey} => \&findkey,
817 $packet_types->{sec_subkey} => \&findkey };
819 packetwalk($instr, $subs, $data);
821 return $data->{key}->{rsa};
828 my $packetlen = shift;
830 findkey($data, $instr, $tag, $packetlen);
831 if (defined($data->{key})) {
832 if (defined($data->{key}->{rsa}) && defined($data->{key}->{timestamp})) {
833 $data->{keys}->{fingerprint($data->{key}->{rsa}, $data->{key}->{timestamp})} = $data->{key};
835 die "should have found some key here";
841 sub getallprimarykeys {
844 my $subs = { $packet_types->{pubkey} => \&findkeyfprs,
845 $packet_types->{seckey} => \&findkeyfprs,
847 my $data = {target => { } };
849 packetwalk($instr, $subs, $data);
851 if (defined $data->{keys}) {
852 return $data->{keys};
864 if ((! defined $fpr) ||
865 (length($fpr) < 8)) {
866 die "We need at least 8 hex digits of fingerprint.\n";
871 if (! defined $uid) {
872 die "No User ID defined.\n";
875 my $data = { target => { fpr => $fpr,
879 my $subs = { $packet_types->{seckey} => \&findkey,
880 $packet_types->{uid} => \&finduid,
881 $packet_types->{sig} => \&findsig,
884 packetwalk($instr, $subs, $data);
886 if ((! defined $data->{key}) ||
887 (! defined $data->{key}->{rsa}) ||
888 (! defined $data->{key}->{timestamp})) {
889 die "The key requested was not found.\n"
892 if (defined $data->{uid}->{$uid}) {
893 die "The requested User ID '$uid' is already associated with this key.\n";
895 $args->{key_timestamp} = $data->{key}->{timestamp};
898 make_packet($packet_types->{pubkey}, make_rsa_pub_key_body($data->{key}->{rsa}, $data->{key}->{timestamp})).
899 make_packet($packet_types->{uid}, $uid).
900 makeselfsig($data->{key}->{rsa},
913 if ((! defined $fpr) ||
914 (length($fpr) < 8)) {
915 die "We need at least 8 hex digits of fingerprint.\n";
920 if (! defined $uid) {
921 die "No User ID defined.\n";
924 my $data = { target => { fpr => $fpr,
928 my $subs = { $packet_types->{seckey} => \&findkey,
929 $packet_types->{uid} => \&finduid,
930 $packet_types->{sig} => \&findsig,
933 packetwalk($instr, $subs, $data);
935 if ((! defined $data->{uid}) ||
936 (! defined $data->{uid}->{$uid})) {
937 die "The User ID \"$uid\" is not associated with this key";
940 if ((! defined $data->{key}) ||
941 (! defined $data->{key}->{rsa}) ||
942 (! defined $data->{key}->{timestamp})) {
943 die "The key requested was not found."
946 my $revocation_reason = 'No longer using this hostname';
947 if (defined $data->{revocation_reason}) {
948 $revocation_reason = $data->{revocation_reason};
951 my $rev_reason_subpkt = prefixsubpacket(pack('CC',
952 $subpacket_types->{revocation_reason},
953 $revocation_reasons->{user_id_no_longer_valid}).
956 if (! defined $sigtime) {
959 # what does a signature like this look like?
960 my $args = { key_timestamp => $data->{key}->{timestamp},
961 sig_timestamp => $sigtime,
962 certification_type => $sig_types->{certification_revocation},
963 hashed_subpackets => $rev_reason_subpkt,
967 make_packet($packet_types->{pubkey}, make_rsa_pub_key_body($data->{key}->{rsa}, $data->{key}->{timestamp})).
968 make_packet($packet_types->{uid}, $uid).
969 join('', @{$data->{sigs}}).
970 gensig($data->{key}->{rsa}, $uid, $args);
974 # see 5.2.3.1 for tips on how to calculate the length of a subpacket:
975 sub prefixsubpacket {
976 my $subpacket = shift;
978 my $len = length($subpacket);
983 $prefix = pack('C', $len);
984 } elsif ($len < 16576) {
986 my $second = $in%256;
987 my $first = ($in - $second)>>8;
988 $prefix = pack('CC', $first + 192, $second)
990 $prefix = pack('CN', 255, $len);
992 return $prefix.$subpacket;
1006 while (! eof($instr)) {
1007 read($instr, $packettag, 1);
1008 $packettag = ord($packettag);
1011 if ( ! (0x80 & $packettag)) {
1012 die "This is not an OpenPGP packet\n";
1014 if (0x40 & $packettag) {
1015 # this is a new-format packet.
1016 $tag = (0x3f & $packettag);
1018 read($instr, $nextlen, 1);
1019 $nextlen = ord($nextlen);
1020 if ($nextlen < 192) {
1021 $packetlen = $nextlen;
1022 } elsif ($nextlen < 224) {
1024 read($instr, $newoct, 1);
1025 $newoct = ord($newoct);
1026 $packetlen = (($nextlen - 192) << 8) + ($newoct) + 192;
1027 } elsif ($nextlen == 255) {
1028 read($instr, $nextlen, 4);
1029 $packetlen = unpack('N', $nextlen);
1031 # packet length is undefined.
1034 # this is an old-format packet.
1036 $lentype = 0x03 & $packettag;
1037 $tag = ( 0x3c & $packettag ) >> 2;
1038 if ($lentype == 0) {
1039 read($instr, $packetlen, 1) or die "could not read packet length\n";
1040 $packetlen = unpack('C', $packetlen);
1041 } elsif ($lentype == 1) {
1042 read($instr, $packetlen, 2) or die "could not read packet length\n";
1043 $packetlen = unpack('n', $packetlen);
1044 } elsif ($lentype == 2) {
1045 read($instr, $packetlen, 4) or die "could not read packet length\n";
1046 $packetlen = unpack('N', $packetlen);
1048 # packet length is undefined.
1052 if (! defined($packetlen)) {
1053 die "Undefined packet lengths are not supported.\n";
1056 if (defined $subs->{$tag}) {
1057 $subs->{$tag}($data, $instr, $tag, $packetlen);
1059 read($instr, $dummy, $packetlen) or die "Could not skip past this packet!\n";
1063 return $data->{key};
1067 for (basename($0)) {
1068 if (/^pem2openpgp$/) {
1073 defined($uid) or die "You must specify a user ID string.\n";
1075 # FIXME: fail if there is no given user ID; or should we default to
1076 # hostname_long() from Sys::Hostname::Long ?
1078 if (defined $ENV{PEM2OPENPGP_NEWKEY}) {
1079 $rsa = Crypt::OpenSSL::RSA->generate_key($ENV{PEM2OPENPGP_NEWKEY});
1086 $rsa = Crypt::OpenSSL::RSA->new_private_key($stdin);
1089 my $key_timestamp = $ENV{PEM2OPENPGP_KEY_TIMESTAMP};
1090 my $sig_timestamp = $ENV{PEM2OPENPGP_TIMESTAMP};
1091 $sig_timestamp = time() if (!defined $sig_timestamp);
1092 $key_timestamp = $sig_timestamp if (!defined $key_timestamp);
1095 make_packet($packet_types->{seckey}, make_rsa_sec_key_body($rsa, $key_timestamp)).
1096 make_packet($packet_types->{uid}, $uid).
1099 { sig_timestamp => $sig_timestamp,
1100 key_timestamp => $key_timestamp,
1101 expiration => $ENV{PEM2OPENPGP_EXPIRATION},
1102 usage_flags => $ENV{PEM2OPENPGP_USAGE_FLAGS},
1106 elsif (/^openpgp2ssh$/) {
1109 open($instream,'-');
1110 binmode($instream, ":bytes");
1111 my $key = openpgp2rsa($instream, $fpr);
1112 if (defined($key)) {
1113 if ($key->is_private()) {
1114 print $key->get_private_key_string();
1116 print "ssh-rsa ".encode_base64(openssh_pubkey_pack($key), '')."\n";
1119 die "No matching key found.\n";
1122 elsif (/^keytrans$/) {
1123 # subcommands when keytrans is invoked directly are UNSUPPORTED,
1124 # UNDOCUMENTED, and WILL NOT BE MAINTAINED.
1125 my $subcommand = shift;
1127 if (/^revokeuserid$/) {
1131 open($instream,'-');
1132 binmode($instream, ":bytes");
1134 my $revcert = revokeuserid($instream, $fpr, $uid, $ENV{PEM2OPENPGP_TIMESTAMP});
1137 } elsif (/^adduserid$/) {
1141 open($instream,'-');
1142 binmode($instream, ":bytes");
1143 my $newuid = adduserid($instream, $fpr, $uid,
1144 { sig_timestamp => $ENV{PEM2OPENPGP_TIMESTAMP},
1145 expiration => $ENV{PEM2OPENPGP_EXPIRATION},
1146 usage_flags => $ENV{PEM2OPENPGP_USAGE_FLAGS},
1150 } elsif (/^listfprs$/) {
1152 open($instream,'-');
1153 binmode($instream, ":bytes");
1154 my $keys = getallprimarykeys($instream);
1155 printf("%s\n", join("\n", map { uc(unpack('H*', $_)) } keys(%{$keys})));
1156 } elsif (/^sshfpr$/) {
1160 while (($dummy,$b64keyblob) = split(/ /, <STDIN>)) {
1161 printf("%s\n", sshfpr(decode_base64($b64keyblob)));
1163 } elsif (/^openpgp2sshfpr$/) {
1166 open($instream,'-');
1167 binmode($instream, ":bytes");
1168 my $key = openpgp2rsa($instream, $fpr);
1169 if (defined($key)) {
1170 # openssh uses MD5 for key fingerprints:
1171 printf("%d %s %s\n",
1172 $key->size() * 8, # size() is in bytes -- we want bits
1173 sshfpr(openssh_pubkey_pack($key)),
1174 '(RSA)', # FIXME when we support other than RSA.
1177 die "No matching key found.\n";
1180 die "Unrecognized subcommand. keytrans subcommands are not a stable interface!\n";
1185 die "Unrecognized keytrans call.\n";