gpg: Prepare revocation keys for use with v5 keys.

* g10/packet.h (struct revocation_key): Add field 'fprlen'.
* g10/parse-packet.c (parse_revkeys): Set fprlen and allow for v5
keys.  Also fix reading of unitialized data at place where
MAX_FINGERPRINT_LEN is used.
* g10/revoke.c (gen_desig_revoke): Allow for v5 keys and use fprlen.
Do an explicit compare to avoid reading unitialized data.
* g10/sig-check.c (check_revocation_keys): Use the fprlen.
* g10/getkey.c (merge_selfsigs_main): Do an explicit copy to avoid
reading unitialized data.
* g10/import.c (revocation_present): Use fprlen.
* g10/keyedit.c (show_key_with_all_names): Use fprlen.
(menu_addrevoker): Use fprlen.  Allow for v5 keys.
* g10/keygen.c (keygen_add_revkey): Use fprlen.
(parse_revocation_key): Allow for v5 keys.
* g10/keyid.c (keyid_from_fingerprint): Allow for v5 keys.  Print a
better error message in case of bogus fingerprints.
* g10/keylist.c (print_revokers): Use fprlen.
--

The reading of uninitialized data is harmless but we better fix it to
make valgrind happy.  More serious was that we always passed
MAX_FINGERPRINT_LEN but we will need to support 20 and 32 octet
fingerprints and MAX_FINGERPRINT_LEN would be too large for a v4.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 16 insertions, 13 deletions

diff --git a/g10/revoke.c b/g10/revoke.c
index b778684b0..e8ce3544c 100644
--- a/g10/revoke.c
+++ b/g10/revoke.c
@@ -277,12 +277,12 @@ gen_desig_revoke (ctrl_t ctrl, const char *uname, strlist_t locusr)
 
 		fingerprint_from_pk (list->pk, fpr, &fprlen);
 
-		/* Don't get involved with keys that don't have 160
-		   bit fingerprints */
-		if(fprlen!=20)
+		/* Don't get involved with keys that don't have a v4
+		 * or v5 fingerprint */
+		if (fprlen != 20 && fprlen != 32)
 		  continue;
 
-		if(memcmp(fpr,pk->revkey[i].fpr,20)==0)
+		if (!memcmp(fpr,pk->revkey[i].fpr, fprlen))
 		  break;
 	      }
 
@@ -295,7 +295,7 @@ gen_desig_revoke (ctrl_t ctrl, const char *uname, strlist_t locusr)
 	  {
 	    pk2 = xmalloc_clear (sizeof *pk2);
 	    rc = get_pubkey_byfprint (ctrl, pk2, NULL,
-                                      pk->revkey[i].fpr, MAX_FINGERPRINT_LEN);
+                                      pk->revkey[i].fpr, pk->revkey[i].fprlen);
 	  }
 
 	/* We have the revocation key.  */
@@ -388,15 +388,18 @@ gen_desig_revoke (ctrl_t ctrl, const char *uname, strlist_t locusr)
 
 		    for(j=0;j<signode->pkt->pkt.signature->numrevkeys;j++)
 		      {
-			if(pk->revkey[i].class==
-			   signode->pkt->pkt.signature->revkey[j].class &&
-			   pk->revkey[i].algid==
-			   signode->pkt->pkt.signature->revkey[j].algid &&
-			   memcmp(pk->revkey[i].fpr,
-				  signode->pkt->pkt.signature->revkey[j].fpr,
-				  MAX_FINGERPRINT_LEN)==0)
+			if (pk->revkey[i].class
+                               == signode->pkt->pkt.signature->revkey[j].class
+                            && pk->revkey[i].algid
+                                == signode->pkt->pkt.signature->revkey[j].algid
+                            && pk->revkey[i].fprlen
+                               == signode->pkt->pkt.signature->revkey[j].fprlen
+                            && !memcmp
+                                 (pk->revkey[i].fpr,
+                                  signode->pkt->pkt.signature->revkey[j].fpr,
+                                  pk->revkey[i].fprlen))
 			  {
-			    revkey=signode->pkt->pkt.signature;
+			    revkey = signode->pkt->pkt.signature;
 			    break;
 			  }
 		      }