Changeset 89d736a

Timestamp:

2008-06-22T19:21:06Z (16 years ago)

Author:

Wilmer van der Gaast <wilmer@…>

Branches:

master

Children:

dfbb056

Parents:

fab3d2d

Message:

From the department of over-engineering, now cached packet IDs are full
MD5 hashes instead of a known MD5 hash with a number. Just to make it
harder to confuse BitlBee by sending it faked responses to packets.

Location:

protocols/jabber

Files:

• jabber.c (modified) (3 diffs)
• jabber.h (modified) (1 diff)
• jabber_util.c (modified) (4 diffs)

protocols/jabber/jabber.c

@@ -33 +33 @@
 #include "jabber.h"
 #include "md5.h"
-#include "base64.h"
 
 GSList *jabber_connections;
@@ -241 +240 @@
 }
 
+/* This generates an unfinished md5_state_t variable. Every time we generate
+   an ID, we finish the state by adding a sequence number and take the hash. */
 static void jabber_generate_id_hash( struct jabber_data *jd )
 {
-        md5_state_t id_hash;
-        md5_byte_t binbuf[16];
+        md5_byte_t binbuf[4];
         char *s;
         
-        md5_init( &id_hash );
-        md5_append( &id_hash, (unsigned char *) jd->username, strlen( jd->username ) );
-        md5_append( &id_hash, (unsigned char *) jd->server, strlen( jd->server ) );
+        md5_init( &jd->cached_id_prefix );
+        md5_append( &jd->cached_id_prefix, (unsigned char *) jd->username, strlen( jd->username ) );
+        md5_append( &jd->cached_id_prefix, (unsigned char *) jd->server, strlen( jd->server ) );
         s = set_getstr( &jd->ic->acc->set, "resource" );
-        md5_append( &id_hash, (unsigned char *) s, strlen( s ) );
-        random_bytes( binbuf, 16 );
-        md5_append( &id_hash, binbuf, 16 );
-        md5_finish( &id_hash, binbuf );
-        
-        s = base64_encode( binbuf, 9 );
-        jd->cached_id_prefix = g_strdup_printf( "%s%s", JABBER_CACHED_ID, s );
-        g_free( s );
+        md5_append( &jd->cached_id_prefix, (unsigned char *) s, strlen( s ) );
+        random_bytes( binbuf, 4 );
+        md5_append( &jd->cached_id_prefix, binbuf, 4 );
 }
 
@@ -289 +284 @@
         xt_free( jd->xt );
         
-        g_free( jd->cached_id_prefix );
         g_free( jd->away_message );
         g_free( jd->username );

protocols/jabber/jabber.h

@@ -86 +86 @@
         char *away_message;
         
-        char *cached_id_prefix;
+        md5_state_t cached_id_prefix;
         GHashTable *node_cache;
         GHashTable *buddies;

protocols/jabber/jabber_util.c

@@ -23 +23 @@
 
 #include "jabber.h"
+#include "md5.h"
+#include "base64.h"
 
 static unsigned int next_id = 1;
@@ -134 +136 @@
         struct jabber_data *jd = ic->proto_data;
         struct jabber_cache_entry *entry = g_new0( struct jabber_cache_entry, 1 );
-        char *id;
-        
-        id = g_strdup_printf( "%s%05x", jd->cached_id_prefix, ( next_id++ ) & 0xfffff );
+        md5_state_t id_hash;
+        md5_byte_t id_sum[16];
+        char *id, *asc_hash;
+        
+        next_id ++;
+        
+        id_hash = jd->cached_id_prefix;
+        md5_append( &id_hash, (md5_byte_t*) &next_id, sizeof( next_id ) );
+        md5_finish( &id_hash, id_sum );
+        asc_hash = base64_encode( id_sum, 12 );
+        
+        id = g_strdup_printf( "%s%s", JABBER_CACHED_ID, asc_hash );
         xt_add_attr( node, "id", id );
         g_free( id );
+        g_free( asc_hash );
         
         entry->node = node;
@@ -184 +196 @@
         
         if( ( s = xt_find_attr( node, "id" ) ) == NULL ||
-            strncmp( s, jd->cached_id_prefix, strlen( jd->cached_id_prefix ) ) != 0 )
+            strncmp( s, JABBER_CACHED_ID, strlen( JABBER_CACHED_ID ) ) != 0 )
         {
                 /* Silently ignore it, without an ID (or a non-cache
@@ -196 +208 @@
         if( entry == NULL )
         {
+                /*
+                There's no longer an easy way to see if we generated this
+                one or someone else, and there's a ten-minute timeout anyway,
+                so meh.
+                
                 imcb_log( ic, "Warning: Received %s-%s packet with unknown/expired ID %s!",
                               node->name, xt_find_attr( node, "type" ) ? : "(no type)", s );
+                */
         }
         else if( entry->func )