diff options
| -rwxr-xr-x | src/keytrans/pem2openpgp | 329 |
1 files changed, 172 insertions, 157 deletions
diff --git a/src/keytrans/pem2openpgp b/src/keytrans/pem2openpgp index 2631da6..3492361 100755 --- a/src/keytrans/pem2openpgp +++ b/src/keytrans/pem2openpgp @@ -32,12 +32,6 @@ 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, @@ -348,172 +342,193 @@ 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); +my $rsa; +if (defined $ENV{PEM2OPENPGP_NEWKEY}) { + $rsa = Crypt::OpenSSL::RSA->generate_key($ENV{PEM2OPENPGP_NEWKEY}); +} else { + # slurp in the entire stdin: + undef $/; + my $stdin = <STDIN>; -# 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); + $rsa = Crypt::OpenSSL::RSA->new_private_key($stdin); } +my $uid = shift; -# 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}, $sig_body); +# FIXME: fail if there is no given user ID; or should we default to +# hostname_long() from Sys::Hostname::Long ? +print pem2openpgp($rsa, + $uid, + { timestamp => $ENV{PEM2OPENPGP_TIMESTAMP}, + expiration => $ENV{PEM2OPENPGP_EXPIRATION}, + usage_flags => $ENV{PEM2OPENPGP_USAGE_FLAGS}, + } + ); |