From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Date: Sat, 10 Jan 2009 23:42:57 +0000 (-0500)
Subject: pem2openpgp: replace raw numbers with semantic labelling to make it more readable.
X-Git-Tag: monkeysphere_0.23~163^2~12
X-Git-Url: https://codewiz.org/gitweb?a=commitdiff_plain;h=3f5960cf4ba2f938c677c27e3296e6feae2f56aa;p=monkeysphere.git

pem2openpgp: replace raw numbers with semantic labelling to make it more readable.
---

diff --git a/src/keytrans/pem2openpgp b/src/keytrans/pem2openpgp
index 382e14f..637eba2 100755
--- a/src/keytrans/pem2openpgp
+++ b/src/keytrans/pem2openpgp
@@ -208,6 +208,7 @@ my $subpacket_types = { sig_creation_time => 2,
 			issuer => 16,
 			notation => 20,
 			preferred_digest => 21,
+			preferred_compression => 22,
 			keyserver_prefs => 23,
 			preferred_keyserver => 24,
 			primary_uid => 25,
@@ -220,6 +221,14 @@ my $subpacket_types = { sig_creation_time => 2,
 			embedded_signature => 32,
 		       };
 
+# bitstring (see RFC 4880 section 5.2.3.24)
+my $features = { mdc => 0x01
+	       };
+
+# bitstring (see RFC 4880 5.2.3.17)
+my $keyserver_prefs = { nomodify => 0x80
+		      };
+
 # we're just not dealing with newline business right now.  slurp in
 # the whole file.
 undef $/;
@@ -240,11 +249,11 @@ if (! $rsa->check_key()) {
 
 my $version = pack('C', 4);
 # strong assertion of identity:
-my $sigtype = pack('C', 0x13);
+my $sigtype = pack('C', $sig_types->{positive_certification});
 # RSA
-my $pubkey_algo = pack('C', 1);
+my $pubkey_algo = pack('C', $asym_algos->{rsa});
 # SHA1
-my $hash_algo = pack('C', 2);
+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
@@ -254,36 +263,51 @@ my $hash_algo = pack('C', 2);
 # could an environment variable (if set) override the current time?
 my $timestamp = time();
 
-my $creation_time_packet = pack('CCN', 5, 2, $timestamp);
+my $creation_time_packet = pack('CCN', 5, $subpacket_types->{sig_creation_time}, $timestamp);
 
 
 # FIXME: HARDCODED: what if someone wants to select a different set of
 # usage flags?  For now, we do only authentication.
-my $flags = $usage_flags->{authenticate};
-my $usage_packet = pack('CCC', 2, 27, $flags);
+my $usage_packet = pack('CCC', 2, $subpacket_types->{usage_flags}, $usage_flags->{authenticate});
 
 
 # FIXME: HARDCODED: how should we determine how far off to set the
 # expiration date?  default is to expire in 2 days, which is insanely
 # short (but good for testing).
 my $expires_in = 86400*2;
-my $expiration_packet = pack('CCN', 5, 9, $expires_in);
+my $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, 11, 9, 8, 7, 3, 2);
+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, 21, 2, 8, 3);
+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, 22, 2, 3, 1);
+my $pref_zip_algos = pack('CCCCC', 4, $subpacket_types->{preferred_compression},
+			  $zips->{zlib},
+			  $zips->{bzip2},
+			  $zips->{zip}
+			 );
 
 # we support the MDC feature:
-my $features = pack('CCC', 2, 30, 1);
+my $feature_subpacket = pack('CCC', 2, $subpacket_types->{features},
+			     $features->{mdc});
 
 # keyserver preference: only owner modify (???):
-my $keyserver_pref = pack('CCC', 2, 23, 0x80);
+my $keyserver_pref = pack('CCC', 2, $subpacket_types->{keyserver_prefs},
+			  $keyserver_prefs->{nomodify});
 
 my $subpackets_to_be_hashed =
   $creation_time_packet.
@@ -292,7 +316,7 @@ my $subpackets_to_be_hashed =
   $pref_sym_algos.
   $pref_hash_algos.
   $pref_zip_algos.
-  $features.
+  $feature_subpacket.
   $keyserver_pref;
 
 my $subpacket_octets = pack('n', length($subpackets_to_be_hashed));
@@ -307,8 +331,7 @@ my $sig_data_to_be_hashed =
 
 my $pubkey = make_rsa_pub_key_body($rsa, $timestamp);
 
-#open(KEYFILE, "</home/wt215/gpg-test/key-data");
-my $key_data = make_packet(6, $pubkey);
+my $key_data = make_packet($packet_types->{pubkey}, $pubkey);
 
 # take the last 8 bytes of the fingerprint as the keyid:
 my $keyid = substr(fingerprint($rsa, $timestamp), 20 - 8, 8);
@@ -332,7 +355,7 @@ my $datatosign =
 my $data_hash = Digest::SHA1::sha1_hex($datatosign);
 
 
-my $issuer_packet = pack('CCa8', 9, 16, $keyid);
+my $issuer_packet = pack('CCa8', 9, $subpacket_types->{issuer}, $keyid);
 
 my $sig = Crypt::OpenSSL::Bignum->new_from_bin($rsa->sign($datatosign));
 
@@ -344,8 +367,8 @@ my $sig_body =
   mpi_pack($sig);
 
 print
-  make_packet(6, $pubkey).
-  make_packet(13, $uid).
-  make_packet(2, $sig_body);
+  make_packet($packet_types->{pubkey}, $pubkey).
+  make_packet($packet_types->{uid}, $uid).
+  make_packet($packet_types->{sig}, $sig_body);