return pack('n', $mpilen).$val;
}
+# takes a Crypt::OpenSSL::Bignum, returns an MPI packed in preparation
+# for an OpenSSH-style public key format. see:
+# http://marc.info/?l=openssh-unix-dev&m=121866301718839&w=2
+sub openssh_mpi_pack {
+ my $num = shift;
+
+ my $val = $num->to_bin();
+ my $mpilen = length($val);
+
+ my $ret = pack('N', $mpilen);
+
+ # if the first bit of the leading byte is high, we should include a
+ # 0 byte:
+ if (ord($val) & 0x80) {
+ $ret = pack('NC', $mpilen+1, 0);
+ }
+
+ return $ret.$val;
+}
+
+sub openssh_pubkey_pack {
+ my $key = shift;
+
+ my ($modulus, $exponent) = $key->get_key_parameters();
+
+ return openssh_mpi_pack(Crypt::OpenSSL::Bignum->new_from_bin("ssh-rsa")).
+ openssh_mpi_pack($exponent).
+ openssh_mpi_pack($modulus);
+}
+
+# pull an OpenPGP-specified MPI off of a given stream, returning it as
+# a Crypt::OpenSSL::Bignum.
+sub read_mpi {
+ my $instr = shift;
+ my $readtally = shift;
+
+ my $bitlen;
+ read($instr, $bitlen, 2) or die "could not read MPI length.\n";
+ $bitlen = unpack('n', $bitlen);
+ $$readtally += 2;
+
+ my $bytestoread = ($bitlen + 7)/8;
+ my $ret;
+ read($instr, $ret, $bytestoread) or die "could not read MPI body.\n";
+ $$readtally += $bytestoread;
+ return Crypt::OpenSSL::Bignum->new_from_bin($ret);
+}
+
+
# FIXME: genericize these to accept either RSA or DSA keys:
sub make_rsa_pub_key_body {
my $key = shift;
}
+sub openpgp2ssh {
+ my $instr = shift;
+ my $fpr = shift;
+
+ if (defined $fpr) {
+ if (length($fpr) < 8) {
+ die "We need at least 8 hex digits of fingerprint.\n";
+ }
+ $fpr = uc($fpr);
+ }
+
+ my $packettag;
+ my $dummy;
+ my $tag;
+
+ my $key;
+
+ while (! eof($instr)) {
+ read($instr, $packettag, 1);
+ $packettag = ord($packettag);
+
+ my $packetlen;
+ if ( ! (0x80 & $packettag)) {
+ die "This is not an OpenPGP packet\n";
+ }
+ if (0x40 & $packettag) {
+ $tag = (0x3f & $packettag);
+ my $nextlen = 0;
+ read($instr, $nextlen, 1);
+ $nextlen = ord($nextlen);
+ if ($nextlen < 192) {
+ $packetlen = $nextlen;
+ } elsif ($nextlen < 224) {
+ my $newoct;
+ read($instr, $newoct, 1);
+ $newoct = ord($newoct);
+ $packetlen = (($nextlen - 192) << 8) + ($newoct) + 192;
+ } elsif ($nextlen == 255) {
+ read($instr, $nextlen, 4);
+ $packetlen = unpack('N', $nextlen);
+ } else {
+ # packet length is undefined.
+ }
+ } else {
+ my $lentype;
+ $lentype = 0x03 & $packettag;
+ $tag = ( 0x3c & $packettag ) >> 2;
+ if ($lentype == 0) {
+ read($instr, $packetlen, 1) or die "could not read packet length\n";
+ $packetlen = unpack('C', $packetlen);
+ } elsif ($lentype == 1) {
+ read($instr, $packetlen, 2) or die "could not read packet length\n";
+ $packetlen = unpack('n', $packetlen);
+ } elsif ($lentype == 2) {
+ read($instr, $packetlen, 4) or die "could not read packet length\n";
+ $packetlen = unpack('N', $packetlen);
+ } else {
+ # packet length is undefined.
+ }
+ }
+
+ if (! defined($packetlen)) {
+ die "Undefined packet lengths are not supported.\n";
+ }
+
+ if ($tag == $packet_types->{pubkey} ||
+ $tag == $packet_types->{pub_subkey} ||
+ $tag == $packet_types->{seckey} ||
+ $tag == $packet_types->{sec_subkey}) {
+ my $ver;
+ my $readbytes = 0;
+ read($instr, $ver, 1) or die "could not read key version\n";
+ $readbytes += 1;
+ $ver = ord($ver);
+
+ if ($ver != 4) {
+ printf(STDERR "We only work with version 4 keys. This key appears to be version %s.\n", $ver);
+ read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
+ } else {
+
+ my $timestamp;
+ read($instr, $timestamp, 4) or die "could not read key timestamp.\n";
+ $readbytes += 4;
+ $timestamp = unpack('N', $timestamp);
+
+ my $algo;
+ read($instr, $algo, 1) or die "could not read key algorithm.\n";
+ $readbytes += 1;
+ $algo = ord($algo);
+ if ($algo != $asym_algos->{rsa}) {
+ printf(STDERR "We only support RSA keys (this key used algorithm %d).\n", $algo);
+ read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
+ } else {
+ ## we have an RSA key.
+ my $modulus = read_mpi($instr, \$readbytes);
+ my $exponent = read_mpi($instr, \$readbytes);
+
+ my $pubkey = Crypt::OpenSSL::RSA->new_key_from_parameters($modulus, $exponent);
+ my $foundfpr = fingerprint($pubkey, $timestamp);
+
+ my $foundfprstr = Crypt::OpenSSL::Bignum->new_from_bin($foundfpr)->to_hex();
+
+ # is this a match?
+ if ((!defined($fpr)) ||
+ (substr($foundfprstr, -1 * length($fpr)) eq $fpr)) {
+ if (defined($key)) {
+ die "Found two matching keys.\n";
+ }
+ $key = $pubkey;
+ }
+
+ if ($tag == $packet_types->{seckey} ||
+ $tag == $packet_types->{sec_subkey}) {
+ if (!defined($key)) { # we don't think the public part of
+ # this key matches
+ read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
+ } else {
+ my $s2k;
+ read($instr, $s2k, 1) or die "Could not read S2K octet.\n";
+ $readbytes += 1;
+ $s2k = ord($s2k);
+ if ($s2k == 0) {
+ # secret material is unencrypted
+ # see http://tools.ietf.org/html/rfc4880#section-5.5.3
+ my $d = read_mpi($instr, \$readbytes);
+ my $p = read_mpi($instr, \$readbytes);
+ my $q = read_mpi($instr, \$readbytes);
+ my $u = read_mpi($instr, \$readbytes);
+
+ my $checksum;
+ read($instr, $checksum, 2) or die "Could not read checksum of secret key material.\n";
+ $readbytes += 2;
+ $checksum = unpack('n', $checksum);
+
+ # FIXME: compare with the checksum! how? the data is
+ # gone into the Crypt::OpenSSL::Bignum
+
+ $key = Crypt::OpenSSL::RSA->new_key_from_parameters($modulus,
+ $exponent,
+ $d,
+ $p,
+ $q);
+
+ $key->check_key() or die "Secret key is not a valid RSA key.\n";
+ } else {
+ print(STDERR "We cannot handle encrypted secret keys. Skipping!\n") ;
+ read($instr, $dummy, $packetlen - $readbytes) or die "Could not skip past this packet.\n";
+ }
+ }
+ }
+
+ }
+ }
+ } else {
+ read($instr, $dummy, $packetlen) or die "Could not skip past this packet!\n";
+ }
+ }
+
+ return $key;
+}
+
+
for (basename($0)) {
if (/^pem2openpgp$/) {
-
my $rsa;
my $stdin;
if (defined $ENV{PEM2OPENPGP_NEWKEY}) {
);
}
elsif (/^openpgp2ssh$/) {
- print STDERR "woo\n";
+ my $fpr = shift;
+ my $instream;
+ open($instream,'-');
+ binmode($instream, ":bytes");
+ my $key = openpgp2ssh($instream, $fpr);
+ if (defined($key)) {
+ if ($key->is_private()) {
+ print $key->get_private_key_string();
+ } else {
+ print "ssh-rsa ".encode_base64(openssh_pubkey_pack($key), '')."\n";
+ }
+ } else {
+ die "No matching key found.\n";
+ }
}
else {
- print STDERR "Unrecognized keytrans call.\n";
- die 1;
+ die "Unrecognized keytrans call.\n";
}
}
projects / monkeysphere.git / blobdiff