Package: gnupg Version: 1.2.5-3 Severity: grave Tags: woody, sarge, patch
Hi.
GnuPG 1.2.5 selects wrong encryption keys (e.g. for my key in the debian keyring). Thus, data is encrypted irreversible, i.e. lost.
When discussed on debian-private in February, I was encouraged to file this bug.
According to upstream, this is fixed by newer installments of the GnuPG (>=1.2.7 IIRC).
Simon Richter pointed out that a fix can be found with
cvs -d :pserver:[EMAIL PROTECTED]:/cvs/gnupg login cvs -d :pserver:[EMAIL PROTECTED]:/cvs/gnupg rdiff -u \ -D'2004/11/29' -D'2004/11/30' gnupg
The attached patch is a version of the above rdiff that cleanly applies to debianized source of gnupg 1.2.5-3 and with it applied gnupg packages without this bug are build.
Kind regards
T.
P.S.: I really would like to see this bug fixed on db.debian.org (or whereever ud-mailgate runs) and would happily try to come up with a patch for the appropriate version of gnupg if that means that I can hope to be able to read ud-mailgate's encrypted mails.
diff -urN gnupg-1.2.5~/g10/getkey.c gnupg-1.2.5/g10/getkey.c
--- gnupg-1.2.5~/g10/getkey.c 2004-05-01 11:19:03.000000000 +0200
+++ gnupg-1.2.5/g10/getkey.c 2005-03-16 19:15:52.000000000 +0100
@@ -1248,6 +1248,51 @@
}
}
+static int
+parse_key_usage(PKT_signature *sig)
+{
+ int key_usage=0;
+ const byte *p;
+ size_t n;
+ byte flags;
+
+ p=parse_sig_subpkt(sig->hashed,SIGSUBPKT_KEY_FLAGS,&n);
+ if(p && n)
+ {
+ /* first octet of the keyflags */
+ flags=*p;
+
+ if(flags & 3)
+ {
+ key_usage |= PUBKEY_USAGE_SIG;
+ flags&=~3;
+ }
+
+ if(flags & 12)
+ {
+ key_usage |= PUBKEY_USAGE_ENC;
+ flags&=~12;
+ }
+
+ if(flags & 0x20)
+ {
+ key_usage |= PUBKEY_USAGE_AUTH;
+ flags&=~0x20;
+ }
+
+ if(flags)
+ key_usage |= PUBKEY_USAGE_UNKNOWN;
+ }
+
+ /* We set PUBKEY_USAGE_UNKNOWN to indicate that this key has a
+ capability that we do not handle. This serves to distinguish
+ between a zero key usage which we handle as the default
+ capabilities for that algorithm, and a usage that we do not
+ handle. */
+
+ return key_usage;
+}
+
/*
* Apply information from SIGNODE (which is the valid self-signature
* associated with that UID) to the UIDNODE:
@@ -1280,17 +1325,7 @@
uid->expiredate = sig->expiredate;
/* store the key flags in the helper variable for later processing */
- uid->help_key_usage = 0;
- p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_FLAGS, &n );
- if ( p && n ) {
- /* first octet of the keyflags */
- if ( (*p & 3) )
- uid->help_key_usage |= PUBKEY_USAGE_SIG;
- if ( (*p & 12) )
- uid->help_key_usage |= PUBKEY_USAGE_ENC;
- /* Note: we do not set the CERT flag here because it can be assumed
- * that thre is no real policy to set it. */
- }
+ uid->help_key_usage=parse_key_usage(sig);
/* ditto or the key expiration */
uid->help_key_expire = 0;
@@ -1486,16 +1521,8 @@
*/
PKT_signature *sig = signode->pkt->pkt.signature;
const byte *p;
- size_t n;
-
- p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_FLAGS, &n );
- if ( p && n ) {
- /* first octet of the keyflags */
- if ( (*p & 3) )
- key_usage |= PUBKEY_USAGE_SIG;
- if ( (*p & 12) )
- key_usage |= PUBKEY_USAGE_ENC;
- }
+
+ key_usage=parse_key_usage(sig);
p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_EXPIRE, NULL);
if ( p ) {
@@ -1831,7 +1858,6 @@
u32 keytimestamp = 0;
u32 key_expire = 0;
const byte *p;
- size_t n;
if ( subnode->pkt->pkttype != PKT_PUBLIC_SUBKEY )
BUG ();
@@ -1890,14 +1916,7 @@
sig = signode->pkt->pkt.signature;
sig->flags.chosen_selfsig=1; /* so we know which selfsig we chose later */
- p = parse_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_FLAGS, &n );
- if ( p && n ) {
- /* first octet of the keyflags */
- if ( (*p & 3) )
- key_usage |= PUBKEY_USAGE_SIG;
- if ( (*p & 12) )
- key_usage |= PUBKEY_USAGE_ENC;
- }
+ key_usage=parse_key_usage(sig);
if ( !key_usage ) { /* no key flags at all: get it from the algo */
key_usage = openpgp_pk_algo_usage ( subpk->pubkey_algo );
}
diff -urN gnupg-1.2.5~/include/cipher.h gnupg-1.2.5/include/cipher.h
--- gnupg-1.2.5~/include/cipher.h 2003-12-03 11:10:16.000000000 +0100
+++ gnupg-1.2.5/include/cipher.h 2005-03-16 19:10:05.000000000 +0100
@@ -51,6 +51,8 @@
#define PUBKEY_USAGE_SIG 1 /* key is good for signatures */
#define PUBKEY_USAGE_ENC 2 /* key is good for encryption */
#define PUBKEY_USAGE_CERT 4 /* key is also good to certify other keys*/
+#define PUBKEY_USAGE_AUTH 8 /* key is good for authentication */
+#define PUBKEY_USAGE_UNKNOWN 128 /* key has an unknown usage bit */
#define DIGEST_ALGO_MD5 1
#define DIGEST_ALGO_SHA1 2
