--- a/libpurple/protocols/mxit/cipher.c Thu Apr 03 03:52:31 2014 +0200
+++ b/libpurple/protocols/mxit/cipher.c Thu Apr 03 04:20:57 2014 +0200
@@ -1,12 +1,9 @@
/*
- * MXit Protocol libPurple Plugin
- *
- * -- encryption --
+ * purple
*
- * Pieter Loubser <libpurple@mxit.com>
- *
- * (C) Copyright 2009 MXit Lifestyle (Pty) Ltd.
- * <http://www.mxitlifestyle.com>
+ * Purple is the legal property of its developers, whose names are too numerous
+ * to list here. Please refer to the COPYRIGHT file distributed with this
+ * source distribution.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -20,92 +17,27 @@
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA
*/
-#include "internal.h"
-#include "debug.h"
+#include "internal.h"
+#include "debug.h"
#include "libpurple/cipher.h"
#include "ciphers/aescipher.h"
-#include "mxit.h"
-#include "cipher.h"
-#include "aes.h"
-
-
-/* encryption */
-#define INITIAL_KEY "6170383452343567"
-#define SECRET_HEADER "<mxit/>"
-#define ENCRYPT_HEADER "<mxitencrypted ver=\"5.2\"/>"
-
+#include "cipher.h"
-/*------------------------------------------------------------------------
- * Add ISO10126 Padding to the data.
- *
- * @param data The data to pad.
- */
-static void padding_add( GString* data )
-{
- unsigned int blocks = ( data->len / 16 ) + 1;
- unsigned int padding = ( blocks * 16 ) - data->len;
-
- g_string_set_size( data, blocks * 16 );
- data->str[data->len - 1] = padding;
-}
-
-
-/*------------------------------------------------------------------------
- * Remove ISO10126 Padding from the data.
- *
- * @param data The data from which to remove padding.
- */
-static void padding_remove( GString* data )
-{
- unsigned int padding;
-
- if ( data->len == 0 )
- return;
+#define INITIAL_KEY "6170383452343567"
+#define SECRET_HEADER "<mxit/>"
- padding = data->str[data->len - 1];
- g_string_truncate( data, data->len - padding );
-}
-
-
-/*------------------------------------------------------------------------
- * Generate the Transport-Layer crypto key.
- * (Note: this function is not-thread safe)
+/**
+ * Encrypt the user's cleartext password using the AES 128-bit (ECB)
+ * encryption algorithm.
*
- * @param session The MXit Session object
- * @return The transport-layer crypto key.
- */
-static char* transport_layer_key( struct MXitSession* session )
-{
- static char key[16 + 1];
- const char* password = purple_connection_get_password( session->con );
- int passlen = strlen( password );
-
- /* initialize with initial key */
- g_strlcpy( key, INITIAL_KEY, sizeof( key ) );
-
- /* client key (8 bytes) */
- memcpy( key, session->clientkey, strlen( session->clientkey ) );
-
- /* add last 8 characters of the PIN (no padding if less characters) */
- if ( passlen <= 8 )
- memcpy( key + 8, password, passlen );
- else
- memcpy( key + 8, password + ( passlen - 8 ), 8 );
-
- return key;
-}
-
-
-/*------------------------------------------------------------------------
- * Encrypt the user's cleartext password using the AES 128-bit (ECB)
- * encryption algorithm.
+ * @param session The MXit session object
*
- * @param session The MXit session object
- * @return The encrypted & encoded password. Must be g_free'd when no longer needed.
+ * @return The encrypted & encoded password. Must be g_free'd when
+ * no longer needed.
*/
gchar *
mxit_encrypt_password(struct MXitSession* session)
@@ -149,103 +81,3 @@
return purple_base64_encode(encrypted, encrypted_size);
}
-
-
-/*------------------------------------------------------------------------
- * Decrypt a message using transport-layer encryption.
- *
- * @param session The MXit session object
- * @param message The encrypted message data (is base64-encoded).
- * @return The decrypted message. Must be g_free'd when no longer needed.
- */
-char* mxit_decrypt_message( struct MXitSession* session, char* message )
-{
- guchar* raw_message;
- gsize raw_len;
- char exkey[512];
- GString* decoded = NULL;
- unsigned int i;
-
- /* remove optional header: <mxitencrypted ver="5.2"/> */
- if ( strncmp( message, ENCRYPT_HEADER, strlen( ENCRYPT_HEADER ) ) == 0 )
- message += strlen( ENCRYPT_HEADER );
-
- /* base64 decode the message */
- raw_message = purple_base64_decode( message, &raw_len );
-
- /* AES-encrypted data is always blocks of 16 bytes */
- if ( ( raw_len == 0 ) || ( raw_len % 16 != 0 ) )
- return NULL;
-
- /* build the AES key */
- ExpandKey( (unsigned char*) transport_layer_key( session ), (unsigned char*) exkey );
-
- /* AES decrypt each block */
- decoded = g_string_sized_new( raw_len );
- for ( i = 0; i < raw_len; i += 16 ) {
- char block[16];
-
- Decrypt( (unsigned char*) raw_message + i, (unsigned char*) exkey, (unsigned char*) block );
- g_string_append_len( decoded, block, 16 );
- }
- g_free( raw_message );
-
- /* check that the decrypted message starts with header: <mxit/> */
- if ( strncmp( decoded->str, SECRET_HEADER, strlen( SECRET_HEADER ) != 0 ) ) {
- g_string_free( decoded, TRUE );
- return NULL; /* message could not be decrypted */
- }
-
- /* remove ISO10126 padding */
- padding_remove( decoded );
-
- /* remove encryption header */
- g_string_erase( decoded, 0, strlen( SECRET_HEADER ) );
-
- return g_string_free( decoded, FALSE );
-}
-
-
-/*------------------------------------------------------------------------
- * Encrypt a message using transport-layer encryption.
- *
- * @param session The MXit session object
- * @param message The message data.
- * @return The encrypted message. Must be g_free'd when no longer needed.
- */
-char* mxit_encrypt_message( struct MXitSession* session, char* message )
-{
- GString* raw_message = NULL;
- char exkey[512];
- GString* encoded = NULL;
- gchar* base64;
- unsigned int i;
-
- purple_debug_info( MXIT_PLUGIN_ID, "encrypt message: '%s'\n", message );
-
- /* append encryption header to message data */
- raw_message = g_string_new( SECRET_HEADER );
- g_string_append( raw_message, message );
- padding_add( raw_message ); /* add ISO10126 padding */
-
- /* build the AES key */
- ExpandKey( (unsigned char*) transport_layer_key( session ), (unsigned char*) exkey );
-
- /* AES encrypt each block */
- encoded = g_string_sized_new( raw_message->len );
- for ( i = 0; i < raw_message->len; i += 16 ) {
- char block[16];
-
- Encrypt( (unsigned char*) raw_message->str + i, (unsigned char*) exkey, (unsigned char*) block );
- g_string_append_len( encoded, block, 16 );
- }
- g_string_free( raw_message, TRUE );
-
- /* base64 encode the encrypted message */
- base64 = purple_base64_encode( (unsigned char *) encoded->str, encoded->len );
- g_string_free( encoded, TRUE );
-
- purple_debug_info( MXIT_PLUGIN_ID, "encrypted message: '%s'\n", base64 );
-
- return base64;
-}