diff options
| -rwxr-xr-x | src/keytrans/pem2openpgp | 514 | ||||
| -rwxr-xr-x | src/transitions/0.23 | 26 |
2 files changed, 376 insertions, 164 deletions
diff --git a/src/keytrans/pem2openpgp b/src/keytrans/pem2openpgp index 2631da6..40188c7 100755 --- a/src/keytrans/pem2openpgp +++ b/src/keytrans/pem2openpgp @@ -23,6 +23,7 @@ use strict; use warnings; +use File::Basename; use Crypt::OpenSSL::RSA; use Crypt::OpenSSL::Bignum; use Crypt::OpenSSL::Bignum::CTX; @@ -32,12 +33,6 @@ use MIME::Base64; ## make sure all length() and substr() calls use bytes only: use bytes; -my $uid = shift; - -# FIXME: fail if there is no given user ID; or should we default to -# hostname_long() from Sys::Hostname::Long ? - - my $old_format_packet_lengths = { one => 0, two => 1, four => 2, @@ -293,6 +288,51 @@ sub mpi_pack { 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 $bitlen; + read($instr, $bitlen, 2) or die "could not read MPI length.\n"; + $bitlen = unpack('n', $bitlen); + + my $ret; + read($instr, $ret, ($bitlen + 7)/8) or die "could not read MPI body.\n"; + 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; @@ -348,172 +388,332 @@ sub fingerprint { } -my $rsa; -if (defined $ENV{PEM2OPENPGP_NEWKEY}) { - $rsa = Crypt::OpenSSL::RSA->generate_key($ENV{PEM2OPENPGP_NEWKEY}); -} else { - # we're just not dealing with newline business right now. slurp in - # the whole file. - undef $/; - $rsa = Crypt::OpenSSL::RSA->new_private_key(<STDIN>); -} +# FIXME: handle DSA keys as well! +sub pem2openpgp { + my $rsa = shift; + my $uid = shift; + my $args = shift; -$rsa->use_sha1_hash(); + $rsa->use_sha1_hash(); -# see page 22 of RFC 4880 for why i think this is the right padding -# choice to use: -$rsa->use_pkcs1_padding(); + # see page 22 of RFC 4880 for why i think this is the right padding + # choice to use: + $rsa->use_pkcs1_padding(); -if (! $rsa->check_key()) { - die "key does not check"; -} + if (! $rsa->check_key()) { + die "key does not check"; + } -my $version = pack('C', 4); -# strong assertion of identity: -my $sigtype = pack('C', $sig_types->{positive_certification}); -# RSA -my $pubkey_algo = pack('C', $asym_algos->{rsa}); -# SHA1 -my $hash_algo = pack('C', $digests->{sha1}); - -# FIXME: i'm worried about generating a bazillion new OpenPGP -# certificates from the same key, which could easily happen if you run -# this script more than once against the same key (because the -# timestamps will differ). How can we prevent this? - -# this environment variable (if set) overrides the current time, to -# be able to create a standard key? If we read the key from a file -# instead of stdin, should we use the creation time on the file? -my $timestamp = 0; -if (defined $ENV{PEM2OPENPGP_TIMESTAMP}) { - $timestamp = ($ENV{PEM2OPENPGP_TIMESTAMP} + 0); -} else { - $timestamp = time(); -} + my $version = pack('C', 4); + # strong assertion of identity: + my $sigtype = pack('C', $sig_types->{positive_certification}); + # RSA + my $pubkey_algo = pack('C', $asym_algos->{rsa}); + # SHA1 + my $hash_algo = pack('C', $digests->{sha1}); + + # FIXME: i'm worried about generating a bazillion new OpenPGP + # certificates from the same key, which could easily happen if you run + # this script more than once against the same key (because the + # timestamps will differ). How can we prevent this? + + # this environment variable (if set) overrides the current time, to + # be able to create a standard key? If we read the key from a file + # instead of stdin, should we use the creation time on the file? + my $timestamp = 0; + if (defined $args->{timestamp}) { + $timestamp = ($args->{timestamp} + 0); + } else { + $timestamp = time(); + } -my $creation_time_packet = pack('CCN', 5, $subpacket_types->{sig_creation_time}, $timestamp); + my $creation_time_packet = pack('CCN', 5, $subpacket_types->{sig_creation_time}, $timestamp); -my $flags = 0; -if (! defined $ENV{PEM2OPENPGP_USAGE_FLAGS}) { - $flags = $usage_flags->{certify}; -} else { - my @ff = split(",", $ENV{PEM2OPENPGP_USAGE_FLAGS}); - foreach my $f (@ff) { - if (! defined $usage_flags->{$f}) { - die "No such flag $f"; + my $flags = 0; + if (! defined $args->{usage_flags}) { + $flags = $usage_flags->{certify}; + } else { + my @ff = split(",", $args->{usage_flags}); + foreach my $f (@ff) { + if (! defined $usage_flags->{$f}) { + die "No such flag $f"; + } + $flags |= $usage_flags->{$f}; } - $flags |= $usage_flags->{$f}; } + + my $usage_packet = pack('CCC', 2, $subpacket_types->{usage_flags}, $flags); + + + # how should we determine how far off to set the expiration date? + # default is no expiration. Specify the timestamp in seconds from the + # key creation. + my $expiration_packet = ''; + if (defined $args->{expiration}) { + my $expires_in = $args->{expiration} + 0; + $expiration_packet = pack('CCN', 5, $subpacket_types->{key_expiration_time}, $expires_in); + } + + + # prefer AES-256, AES-192, AES-128, CAST5, 3DES: + my $pref_sym_algos = pack('CCCCCCC', 6, $subpacket_types->{preferred_cipher}, + $ciphers->{aes256}, + $ciphers->{aes192}, + $ciphers->{aes128}, + $ciphers->{cast5}, + $ciphers->{tripledes} + ); + + # prefer SHA-1, SHA-256, RIPE-MD/160 + my $pref_hash_algos = pack('CCCCC', 4, $subpacket_types->{preferred_digest}, + $digests->{sha1}, + $digests->{sha256}, + $digests->{ripemd160} + ); + + # prefer ZLIB, BZip2, ZIP + my $pref_zip_algos = pack('CCCCC', 4, $subpacket_types->{preferred_compression}, + $zips->{zlib}, + $zips->{bzip2}, + $zips->{zip} + ); + + # we support the MDC feature: + my $feature_subpacket = pack('CCC', 2, $subpacket_types->{features}, + $features->{mdc}); + + # keyserver preference: only owner modify (???): + my $keyserver_pref = pack('CCC', 2, $subpacket_types->{keyserver_prefs}, + $keyserver_prefs->{nomodify}); + + my $subpackets_to_be_hashed = + $creation_time_packet. + $usage_packet. + $expiration_packet. + $pref_sym_algos. + $pref_hash_algos. + $pref_zip_algos. + $feature_subpacket. + $keyserver_pref; + + my $subpacket_octets = pack('n', length($subpackets_to_be_hashed)); + + my $sig_data_to_be_hashed = + $version. + $sigtype. + $pubkey_algo. + $hash_algo. + $subpacket_octets. + $subpackets_to_be_hashed; + + my $pubkey = make_rsa_pub_key_body($rsa, $timestamp); + my $seckey = make_rsa_sec_key_body($rsa, $timestamp); + + # this is for signing. it needs to be an old-style header with a + # 2-packet octet count. + + my $key_data = make_packet($packet_types->{pubkey}, $pubkey, {'packet_length'=>2}); + + # take the last 8 bytes of the fingerprint as the keyid: + my $keyid = substr(fingerprint($rsa, $timestamp), 20 - 8, 8); + + # the v4 signature trailer is: + + # version number, literal 0xff, and then a 4-byte count of the + # signature data itself. + my $trailer = pack('CCN', 4, 0xff, length($sig_data_to_be_hashed)); + + my $uid_data = + pack('CN', 0xb4, length($uid)). + $uid; + + my $datatosign = + $key_data. + $uid_data. + $sig_data_to_be_hashed. + $trailer; + + my $data_hash = Digest::SHA1::sha1_hex($datatosign); + + my $issuer_packet = pack('CCa8', 9, $subpacket_types->{issuer}, $keyid); + + my $sig = Crypt::OpenSSL::Bignum->new_from_bin($rsa->sign($datatosign)); + + my $sig_body = + $sig_data_to_be_hashed. + pack('n', length($issuer_packet)). + $issuer_packet. + pack('n', hex(substr($data_hash, 0, 4))). + mpi_pack($sig); + + return + make_packet($packet_types->{seckey}, $seckey). + make_packet($packet_types->{uid}, $uid). + make_packet($packet_types->{sig}, $sig_body); } -my $usage_packet = pack('CCC', 2, $subpacket_types->{usage_flags}, $flags); +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"; + } + } + + 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 $ver; + read($instr, $ver, 1) or die "could not read key version\n"; + $ver = ord($ver); + if ($ver != 4) { + printf(STDERR "We only work with version 4 keys. This key appears to be version $ver.\n"); + read($instr, $dummy, $packetlen - 1) or die "Could not skip past this packet.\n"; + } else { + + my $timestamp; + read($instr, $timestamp, 4) or die "could not read key timestamp.\n"; + $timestamp = unpack('N', $timestamp); + + my $algo; + read($instr, $algo, 1) or die "could not read key algorithm.\n"; + $algo = ord($algo); + if ($algo != $asym_algos->{rsa}) { + printf(STDERR "We only support RSA keys (this key used algorithm %d).\n", $algo); + read($instr, $dummy, $packetlen - 6) or die "Could not skip past this packet.\n"; + } else { + ## we have an RSA key. + my $modulus = read_mpi($instr); + my $exponent = read_mpi($instr); + + 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 == $packet_types->{sec_subkey}) { + die "Cannot deal with secret keys yet!\n"; + } + + } + } + } else { + read($instr, $dummy, $packetlen) or die "Could not skip past this packet!\n"; + } + } -# how should we determine how far off to set the expiration date? -# default is no expiration. Specify the timestamp in seconds from the -# key creation. -my $expiration_packet = ''; -if (defined $ENV{PEM2OPENPGP_EXPIRATION}) { - my $expires_in = $ENV{PEM2OPENPGP_EXPIRATION} + 0; - $expiration_packet = pack('CCN', 5, $subpacket_types->{key_expiration_time}, $expires_in); + if (defined($key)) { + return "ssh-rsa ".encode_base64(openssh_pubkey_pack($key), ''); + } } -# prefer AES-256, AES-192, AES-128, CAST5, 3DES: -my $pref_sym_algos = pack('CCCCCCC', 6, $subpacket_types->{preferred_cipher}, - $ciphers->{aes256}, - $ciphers->{aes192}, - $ciphers->{aes128}, - $ciphers->{cast5}, - $ciphers->{tripledes} - ); - -# prefer SHA-1, SHA-256, RIPE-MD/160 -my $pref_hash_algos = pack('CCCCC', 4, $subpacket_types->{preferred_digest}, - $digests->{sha1}, - $digests->{sha256}, - $digests->{ripemd160} - ); - -# prefer ZLIB, BZip2, ZIP -my $pref_zip_algos = pack('CCCCC', 4, $subpacket_types->{preferred_compression}, - $zips->{zlib}, - $zips->{bzip2}, - $zips->{zip} - ); - -# we support the MDC feature: -my $feature_subpacket = pack('CCC', 2, $subpacket_types->{features}, - $features->{mdc}); - -# keyserver preference: only owner modify (???): -my $keyserver_pref = pack('CCC', 2, $subpacket_types->{keyserver_prefs}, - $keyserver_prefs->{nomodify}); - -my $subpackets_to_be_hashed = - $creation_time_packet. - $usage_packet. - $expiration_packet. - $pref_sym_algos. - $pref_hash_algos. - $pref_zip_algos. - $feature_subpacket. - $keyserver_pref; - -my $subpacket_octets = pack('n', length($subpackets_to_be_hashed)); - -my $sig_data_to_be_hashed = - $version. - $sigtype. - $pubkey_algo. - $hash_algo. - $subpacket_octets. - $subpackets_to_be_hashed; - -my $pubkey = make_rsa_pub_key_body($rsa, $timestamp); -my $seckey = make_rsa_sec_key_body($rsa, $timestamp); - -# this is for signing. it needs to be an old-style header with a -# 2-packet octet count. - -my $key_data = make_packet($packet_types->{pubkey}, $pubkey, {'packet_length'=>2}); - -# take the last 8 bytes of the fingerprint as the keyid: -my $keyid = substr(fingerprint($rsa, $timestamp), 20 - 8, 8); - -# the v4 signature trailer is: - -# version number, literal 0xff, and then a 4-byte count of the -# signature data itself. -my $trailer = pack('CCN', 4, 0xff, length($sig_data_to_be_hashed)); - -my $uid_data = - pack('CN', 0xb4, length($uid)). - $uid; - -my $datatosign = - $key_data. - $uid_data. - $sig_data_to_be_hashed. - $trailer; - -my $data_hash = Digest::SHA1::sha1_hex($datatosign); - -my $issuer_packet = pack('CCa8', 9, $subpacket_types->{issuer}, $keyid); - -my $sig = Crypt::OpenSSL::Bignum->new_from_bin($rsa->sign($datatosign)); - -my $sig_body = - $sig_data_to_be_hashed. - pack('n', length($issuer_packet)). - $issuer_packet. - pack('n', hex(substr($data_hash, 0, 4))). - mpi_pack($sig); - -print - make_packet($packet_types->{seckey}, $seckey). - make_packet($packet_types->{uid}, $uid). - make_packet($packet_types->{sig}, $sig_body); +for (basename($0)) { + if (/^pem2openpgp$/) { + my $rsa; + my $stdin; + if (defined $ENV{PEM2OPENPGP_NEWKEY}) { + $rsa = Crypt::OpenSSL::RSA->generate_key($ENV{PEM2OPENPGP_NEWKEY}); + } else { + $stdin = do { + local $/; # slurp! + <STDIN>; + }; + $rsa = Crypt::OpenSSL::RSA->new_private_key($stdin); + } + + my $uid = shift; + + # FIXME: fail if there is no given user ID; or should we default to + # hostname_long() from Sys::Hostname::Long ? + + print pem2openpgp($rsa, + $uid, + { timestamp => $ENV{PEM2OPENPGP_TIMESTAMP}, + expiration => $ENV{PEM2OPENPGP_EXPIRATION}, + usage_flags => $ENV{PEM2OPENPGP_USAGE_FLAGS}, + } + ); + } + elsif (/^openpgp2ssh$/) { + my $fpr = shift; + my $instream; + open($instream,'-'); + binmode($instream, ":bytes"); + print openpgp2ssh($instream, $fpr); + } + else { + die "Unrecognized keytrans call.\n"; + } +} diff --git a/src/transitions/0.23 b/src/transitions/0.23 index 67d1f63..b0c967a 100755 --- a/src/transitions/0.23 +++ b/src/transitions/0.23 @@ -154,8 +154,9 @@ if [ -d "$SYSDATADIR"/gnupg-host ] ; then FPR=$(GNUPGHOME="$SYSDATADIR"/gnupg-host gpg --no-permission-warning --with-colons --fixed-list-mode --list-secret-keys --fingerprint | awk -F: '/^fpr:/{ print $10 }' ) # create host home - mkdir -p "${MHDATADIR}" - chmod 0700 "${MHDATADIR}" + mkdir -p $(dirname "$MHDATADIR") + NEWDATADIR=$(mktemp -d "${MHDATADIR}.XXXXXX") + chmod 0700 "${NEWDATADIR}" log "importing host key from old monkeysphere installation\n" @@ -167,10 +168,20 @@ if [ -d "$SYSDATADIR"/gnupg-host ] ; then # FIXME: if all self-sigs are expired, then the secret key import may # fail anyway. How should we deal with that? - (GNUPGHOME="$SYSDATADIR"/gnupg-host gpg --no-permission-warning --export-secret-keys && \ - GNUPGHOME="$SYSDATADIR"/gnupg-host gpg --no-permission-warning --export $FPR) | \ - GNUPGHOME="$MHDATADIR" gpg --quiet --no-tty --import - + if (GNUPGHOME="$SYSDATADIR"/gnupg-host gpg --no-permission-warning --export-secret-keys && \ + GNUPGHOME="$SYSDATADIR"/gnupg-host gpg --no-permission-warning --export "$FPR") | \ + GNUPGHOME="$NEWDATADIR" gpg --quiet --no-tty --import ; then + : we are in good shape! + else + if ! GNUPGHOME="$NEWDATADIR" gpg --list-secret-key >/dev/null ; then + log "The old host key (%s) was not imported properly.\n" "$FPR" + exit 1 + fi + fi + + # if we get here cleanly, then we're OK to move forward: + mv "$NEWDATADIR" "$MHDATADIR" + monkeysphere-host update-gpg-pub-file else log "No host key found in old monkeysphere install; not importing any host key.\n" @@ -192,7 +203,8 @@ fi if [ -d "${SYSDATADIR}/gnupg-authentication" ] ; then GNUPGHOME="${SYSDATADIR}/gnupg-authentication" gpg --no-permission-warning --export | \ - monkeysphere-authentication gpg-cmd --import + monkeysphere-authentication gpg-cmd --import || \ + log "No OpenPGP certificates imported into monkeysphere-authentication trust sphere.\n" mkdir -p "$STASHDIR" chmod 0700 "$STASHDIR" |