Bugfixes: select right password for password authentication, do not

try to process authentication blocks as datablocks, make it possible
to add data at end of packet. Password authentication should actually work.

bird.conf

@@ -33,7 +33,7 @@ protocol rip MyRIP_test {
 	passwords { password "ahoj" from 0 to 10;
 		password "nazdar" from 10;
 	}
-	authentication md5;
+	authentication plaintext;
 }
 
 protocol device {

proto/rip/auth.c

@@ -4,6 +4,7 @@
  *	Copyright (c) 1999 Pavel Machek <pavel@ucw.cz>
  *
  *	Can be freely distributed and used under the terms of the GNU GPL.
+ *
  */
 
 #define LOCAL_DEBUG
@@ -35,15 +36,19 @@ rip_incoming_authentication( struct proto *p, struct rip_block_auth *block, stru
   DBG( "Incoming authentication: " );
   switch (block->authtype) {	/* Authentication type */
   case AT_PLAINTEXT: 
+    {
+      struct password_item *passwd = get_best_password( P_CF->passwords, 0 );
       DBG( "Plaintext passwd" );
-    if (!P_CF->passwords) {
+      if (!passwd) {
 	log( L_AUTH "no passwords set and password authentication came\n" );
 	return 1;
       }
-    if (strncmp( (char *) (&block->packetlen), P_CF->passwords->password, 16)) {
+      if (strncmp( (char *) (&block->packetlen), passwd->password, 16)) {
 	log( L_AUTH "Passwd authentication failed!\n" );
+	DBG( "Expected %s, got %s\n", passwd->password, &block->packetlen );
 	return 1;
       }
+    }
     return 0;
   case AT_MD5:
     DBG( "md5 password" );
@@ -51,12 +56,16 @@ rip_incoming_authentication( struct proto *p, struct rip_block_auth *block, stru
       struct password_item *head;
       struct rip_md5_tail *tail;
 
-      if (block->packetlen != PACKETLEN(num)) {
+      if (block->packetlen != PACKETLEN(num) + 20) {
 	log( L_ERR "packetlen in md5 does not match computed value\n" );
 	return 1;
       }
 
       tail = (struct rip_md5_tail *) ((char *) packet + (block->packetlen - sizeof(struct rip_block_auth)));
+      if ((tail->mustbeFFFF != 0xffff) || (tail->mustbe0001 != 0x0001)) {
+	log( L_ERR "md5 tail signature is not there\n" );
+	return 1;
+      }
 
       head = P_CF->passwords;
       while (head) {
@@ -91,15 +100,19 @@ rip_incoming_authentication( struct proto *p, struct rip_block_auth *block, stru
   return 0;
 }
 
-void
+int
 rip_outgoing_authentication( struct proto *p, struct rip_block_auth *block, struct rip_packet *packet, int num )
 {
   struct password_item *passwd = get_best_password( P_CF->passwords, 0 );
+
+  if (!P_CF->authtype)
+    return PACKETLEN(num);
+
   DBG( "Outgoing authentication: " );
 
   if (!passwd) {
     log( L_ERR "no suitable password found for authentication\n" );
-    return;
+    return PACKETLEN(num);
   }
 
   block->authtype = P_CF->authtype;
@@ -107,7 +120,7 @@ rip_outgoing_authentication( struct proto *p, struct rip_block_auth *block, stru
   switch (P_CF->authtype) {
   case AT_PLAINTEXT:
     password_strncpy( (char *) (&block->packetlen), passwd->password, 16);
-    return;
+    return PACKETLEN(num);
   case AT_MD5:
     {
       struct rip_md5_tail *tail;
@@ -121,8 +134,8 @@ rip_outgoing_authentication( struct proto *p, struct rip_block_auth *block, stru
       block->authlen = 20;
       block->seq = sequence++;
       block->zero0 = 0;
-      block->zero1 = 1;
-      block->packetlen = PACKETLEN(num);
+      block->zero1 = 0;
+      block->packetlen = PACKETLEN(num) + block->authlen;
 
       tail = (struct rip_md5_tail *) ((char *) packet + (block->packetlen - sizeof(struct rip_block_auth)));
       tail->mustbeFFFF = 0xffff;
@@ -132,7 +145,9 @@ rip_outgoing_authentication( struct proto *p, struct rip_block_auth *block, stru
       MD5Init(&ctxt);
       MD5Update(&ctxt, (char *) packet, block->packetlen );
       MD5Final((char *) (&tail->md5), &ctxt);
-      return;
-    }
+      return block->packetlen;
+    }
+  default:
+    bug( "Uknown authtype in outgoing authentication?\n" );
   }
 }

proto/rip/rip.c

@@ -114,7 +114,7 @@ rip_tx( sock *s )
   struct rip_connection *c = rif->busy;
   struct proto *p = c->proto;
   struct rip_packet *packet = (void *) s->tbuf;
-  int i;
+  int i, packetlen;
 
   DBG( "Sending to %I\n", s->daddr );
   do {
@@ -151,17 +151,17 @@ rip_tx( sock *s )
 
   break_loop:
 
-    if (P_CF->authtype)
-      rip_outgoing_authentication(p, (void *) &packet->block[0], packet, i);
+    packetlen = rip_outgoing_authentication(p, (void *) &packet->block[0], packet, i);
 
     DBG( ", sending %d blocks, ", i );
-    if (!i)
+#if 0	/* FIXME: enable this for production! */
+    if (i == !!P_CF->authtype)
       continue;
-
+#endif
     if (ipa_nonzero(c->daddr))
-      i = sk_send_to( s, sizeof( struct rip_packet_heading ) + i*sizeof( struct rip_block ), c->daddr, c->dport );
+      i = sk_send_to( s, packetlen, c->daddr, c->dport );
     else
-      i = sk_send( s, sizeof( struct rip_packet_heading ) + i*sizeof( struct rip_block ) );
+      i = sk_send( s, packetlen );
 
     DBG( "it wants more\n" );
   
@@ -294,13 +294,12 @@ process_block( struct proto *p, struct rip_block *block, ip_addr whotoldme )
   ip_addr network = block->network;
 
   CHK_MAGIC;
+  debug( "block: %I tells me: %I/??? available, metric %d... ", whotoldme, network, metric );
   if ((!metric) || (metric > P_CF->infinity)) {
     log( L_WARN "Got metric %d from %I", metric, whotoldme );
     return;
   }
 
-  debug( "block: %I tells me: %I/??? available, metric %d... ", whotoldme, network, metric );
-
   advertise_entry( p, block, whotoldme );
 }
 
@@ -351,11 +350,13 @@ rip_process_packet( struct proto *p, struct rip_packet *packet, int num, ip_addr
 
           for (i=0; i<num; i++) {
 	    struct rip_block *block = &packet->block[i];
-	    if (block->family == 0xffff)
-	      if (!i) {
+	    if (block->family == 0xffff) {
+	      if (i)
+		BAD( "Authentication header is not the first" );
 	      if (rip_incoming_authentication(p, (void *) block, packet, num))
 		BAD( "Authentication failed" );
 	      authenticated = 1;
+	      continue;
 	    }
 	    if ((!authenticated) && (P_CF->authtype != AT_NONE))
 	      BAD( "Packet is not authenticated and it should be" );

proto/rip/rip.h

@@ -42,7 +42,7 @@ struct rip_packet_heading {
 };
 
 #ifndef IPV6
-struct rip_block {
+struct rip_block {	/* 20 bytes */
   u16 family;	/* 0xffff on first message means this is authentication */
   u16 tag;
   ip_addr network;
@@ -51,7 +51,7 @@ struct rip_block {
   u32 metric;
 };
 #else
-struct rip_block {
+struct rip_block { /* IPv6 version! */
   ip_addr network;
   u16 tag;
   u8 pxlen;
@@ -59,7 +59,7 @@ struct rip_block {
 };
 #endif
 
-struct rip_block_auth {
+struct rip_block_auth { /* 20 bytes */
   u16 mustbeFFFF;
   u16 authtype;
   u16 packetlen;
@@ -70,7 +70,7 @@ struct rip_block_auth {
   u32 zero1;
 };
 
-struct rip_md5_tail {
+struct rip_md5_tail {	/* 20 bytes */
   u16 mustbeFFFF;
   u16 mustbe0001;
   char md5[16];
@@ -158,4 +158,4 @@ void rip_init_config(struct rip_proto_config *c);
 /* Authentication functions */
 
 int rip_incoming_authentication( struct proto *p, struct rip_block_auth *block, struct rip_packet *packet, int num );
-void rip_outgoing_authentication( struct proto *p, struct rip_block_auth *block, struct rip_packet *packet, int num );
+int rip_outgoing_authentication( struct proto *p, struct rip_block_auth *block, struct rip_packet *packet, int num );