* getkey.c (merge_selfsigs_main), main.h, sig-check.c

(check_key_signature2): Pass the ultimately trusted pk directly to
check_key_signature2 to avoid going through the key selection mechanism.
This prevents a deadly embrace when two keys without selfsigs each sign
the other.

4 files changed, 29 insertions, 13 deletions

diff --git a/g10/ChangeLog b/g10/ChangeLog
index 798e4ce71..34020c963 100644
--- a/g10/ChangeLog
+++ b/g10/ChangeLog
@@ -1,3 +1,11 @@
+2002-12-29  David Shaw  <[email protected]>
+
+	* getkey.c (merge_selfsigs_main), main.h, sig-check.c
+	(check_key_signature2): Pass the ultimately trusted pk directly to
+	check_key_signature2 to avoid going through the key selection
+	mechanism.  This prevents a deadly embrace when two keys without
+	selfsigs each sign the other.
+
 2002-12-27  David Shaw  <[email protected]>
 
 	* keyserver.c (keyserver_refresh): Don't print the "refreshing..."
diff --git a/g10/getkey.c b/g10/getkey.c
index abc8b2715..0e41f2d7c 100644
--- a/g10/getkey.c
+++ b/g10/getkey.c
@@ -1571,6 +1571,8 @@ merge_selfsigs_main( KBNODE keyblock, int *r_revoked )
 	    else if ( k->pkt->pkttype == PKT_SIGNATURE && uidnode )
 	      {
 		PKT_signature *sig = k->pkt->pkt.signature;
+		u32 dummy;
+		int dum2;
 
 		if(sig->keyid[0] != kid[0] || sig->keyid[1]!=kid[1])
 		  {
@@ -1584,9 +1586,10 @@ merge_selfsigs_main( KBNODE keyblock, int *r_revoked )
                        trusted key is still valid - if it has been
                        revoked or the user should also renmove the
                        ultimate trust flag.  */
-		    if(get_pubkey_fast(ultimate_pk,sig->keyid)==0 &&
-		       check_key_signature(keyblock,k,NULL)==0 &&
-		       get_ownertrust(ultimate_pk)==TRUST_ULTIMATE)
+		    if(get_pubkey_fast(ultimate_pk,sig->keyid)==0
+		       && check_key_signature2(keyblock,k,ultimate_pk,
+					       NULL,&dummy,&dum2)==0
+		       && get_ownertrust(ultimate_pk)==TRUST_ULTIMATE)
 		      {
 			free_public_key(ultimate_pk);
 			pk->is_valid=1;
diff --git a/g10/main.h b/g10/main.h
index 03d43e112..418653460 100644
--- a/g10/main.h
+++ b/g10/main.h
@@ -113,7 +113,7 @@ int sign_symencrypt_file (const char *fname, STRLIST locusr);
 /*-- sig-check.c --*/
 int check_revocation_keys (PKT_public_key *pk, PKT_signature *sig);
 int check_key_signature( KBNODE root, KBNODE node, int *is_selfsig );
-int check_key_signature2( KBNODE root, KBNODE node,
+int check_key_signature2( KBNODE root, KBNODE node, PKT_public_key *check_pk,
 			  int *is_selfsig, u32 *r_expiredate, int *r_expired );
 
 /*-- delkey.c --*/
diff --git a/g10/sig-check.c b/g10/sig-check.c
index c068e4409..6468cf9ea 100644
--- a/g10/sig-check.c
+++ b/g10/sig-check.c
@@ -475,12 +475,14 @@ check_key_signature( KBNODE root, KBNODE node, int *is_selfsig )
 {
     u32 dummy;
     int dum2;
-    return check_key_signature2(root, node, is_selfsig, &dummy, &dum2 );
+    return check_key_signature2(root, node, NULL, is_selfsig, &dummy, &dum2 );
 }
 
+/* If check_pk is set, then use it to check the signature in node
+   rather than getting it from root or the keydb. */
 int
-check_key_signature2( KBNODE root, KBNODE node, int *is_selfsig,
-				       u32 *r_expiredate, int *r_expired )
+check_key_signature2( KBNODE root, KBNODE node, PKT_public_key *check_pk,
+		      int *is_selfsig, u32 *r_expiredate, int *r_expired )
 {
     MD_HANDLE md;
     PKT_public_key *pk;
@@ -595,14 +597,17 @@ check_key_signature2( KBNODE root, KBNODE node, int *is_selfsig,
 	    md = md_open( algo, 0 );
 	    hash_public_key( md, pk );
 	    hash_uid_node( unode, md, sig );
-	    if( keyid[0] == sig->keyid[0] && keyid[1] == sig->keyid[1] ) {
+	    if( keyid[0] == sig->keyid[0] && keyid[1] == sig->keyid[1] )
+	      {
 		if( is_selfsig )
-		    *is_selfsig = 1;
+		  *is_selfsig = 1;
 		rc = do_check( pk, sig, md, r_expired );
-	    }
-	    else {
-		rc = signature_check2( sig, md, r_expiredate, r_expired );
-	    }
+	      }
+	    else if (check_pk)
+	      rc=do_check(check_pk,sig,md,r_expired);
+	    else
+	      rc = signature_check2( sig, md, r_expiredate, r_expired );
+
             cache_sig_result ( sig, rc );
 	    md_close(md);
 	}