pidgin/ljfisher-ssl-client-auth

Simplify the PIN encryption code.
mxit
2011-08-15, Andrew Victor
b4729e4322f3
Parents b9ede4a1435b
Children 3ead8f25f2a9
Simplify the PIN encryption code.
2 files changed, 30 insertions(+), 61 deletions(-)
  • +29 -60
    libpurple/protocols/mxit/cipher.c
  • +1 -1
    libpurple/protocols/mxit/cipher.h
    • --- a/libpurple/protocols/mxit/cipher.c Mon Aug 15 19:24:16 2011 +0000
    +++ b/libpurple/protocols/mxit/cipher.c Mon Aug 15 20:10:35 2011 +0000
    @@ -1,7 +1,7 @@
    /*
    * MXit Protocol libPurple Plugin
    *
    - * -- user password encryption --
    + * -- encryption --
    *
    * Pieter Loubser <libpurple@mxit.com>
    *
    @@ -31,35 +31,13 @@
    #include "aes.h"
    -/* password encryption */
    +/* encryption */
    #define INITIAL_KEY "6170383452343567"
    #define SECRET_HEADER "<mxit/>"
    #define ENCRYPT_HEADER "<mxitencrypted ver=\"5.2\"/>"
    /*------------------------------------------------------------------------
    - * Pad the secret data using ISO10126 Padding.
    - *
    - * @param secret The data to pad (caller must ensure buffer has enough space for padding)
    - * @return The total number of 128-bit blocks used
    - */
    -static int pad_secret_data( char* secret )
    -{
    - int blocks = 0;
    - int passlen;
    - int padding;
    -
    - passlen = strlen( secret );
    - blocks = ( passlen / 16 ) + 1;
    - padding = ( blocks * 16 ) - passlen;
    - secret[passlen] = 0x50;
    - secret[(blocks * 16) - 1] = padding;
    -
    - return blocks;
    -}
    -
    -
    -/*------------------------------------------------------------------------
    * Add ISO10126 Padding to the data.
    *
    * @param data The data to pad.
    @@ -101,7 +79,7 @@
    static char* transport_layer_key( struct MXitSession* session )
    {
    static char key[16 + 1];
    - int pwdlen = strlen( session->acc->password );
    + int passlen = strlen( session->acc->password );
    /* initialize with initial key */
    g_strlcpy( key, INITIAL_KEY, sizeof( key ) );
    @@ -110,10 +88,10 @@
    memcpy( key, session->clientkey, strlen( session->clientkey ) );
    /* add last 8 characters of the PIN (no padding if less characters) */
    - if ( pwdlen <= 8 )
    - memcpy( key + 8, session->acc->password, pwdlen );
    + if ( passlen <= 8 )
    + memcpy( key + 8, session->acc->password, passlen );
    else
    - memcpy( key + 8, session->acc->password + ( pwdlen - 8 ), 8 );
    + memcpy( key + 8, session->acc->password + ( passlen - 8 ), 8 );
    return key;
    }
    @@ -128,41 +106,35 @@
    */
    char* mxit_encrypt_password( struct MXitSession* session )
    {
    - char key[64];
    + char key[16 + 1];
    char exkey[512];
    - char pass[64];
    + GString* pass = NULL;
    char encrypted[64];
    char* base64;
    - int blocks;
    - int size;
    int i;
    purple_debug_info( MXIT_PLUGIN_ID, "mxit_encrypt_password\n" );
    memset( encrypted, 0x00, sizeof( encrypted ) );
    - memset( exkey, 0x00, sizeof( exkey ) );
    - memset( pass, 0x58, sizeof( pass ) );
    - pass[sizeof( pass ) - 1] = '\0';
    - /* build the custom AES encryption key */
    + /* build the AES encryption key */
    g_strlcpy( key, INITIAL_KEY, sizeof( key ) );
    memcpy( key, session->clientkey, strlen( session->clientkey ) );
    ExpandKey( (unsigned char*) key, (unsigned char*) exkey );
    - /* build the custom data to be encrypted */
    - g_strlcpy( pass, SECRET_HEADER, sizeof( pass ) );
    - strcat( pass, session->acc->password );
    + /* build the secret data to be encrypted: SECRET_HEADER + password */
    + pass = g_string_new( SECRET_HEADER );
    + g_string_append( pass, session->acc->password );
    + padding_add( pass ); /* add ISO10126 padding */
    - /* pad the secret data */
    - blocks = pad_secret_data( pass );
    - size = blocks * 16;
    -
    - /* now encrypt the password. we encrypt each block separately (ECB mode) */
    - for ( i = 0; i < size; i += 16 )
    - Encrypt( (unsigned char*) pass + i, (unsigned char*) exkey, (unsigned char*) encrypted + i );
    + /* now encrypt the secret. we encrypt each block separately (ECB mode) */
    + for ( i = 0; i < pass->len; i += 16 )
    + Encrypt( (unsigned char*) pass->str + i, (unsigned char*) exkey, (unsigned char*) encrypted + i );
    /* now base64 encode the encrypted password */
    - base64 = purple_base64_encode( (unsigned char*) encrypted, size );
    + base64 = purple_base64_encode( (unsigned char*) encrypted, pass->len );
    +
    + g_string_free( pass, TRUE );
    return base64;
    }
    @@ -177,11 +149,11 @@
    */
    char* mxit_decrypt_message( struct MXitSession* session, char* message )
    {
    + guchar* raw_message;
    gsize raw_len;
    - guchar* raw_message;
    char exkey[512];
    + GString* decoded = NULL;
    int i;
    - GString* decoded = NULL;
    /* remove optional header: <mxitencrypted ver="5.2"/> */
    if ( strncmp( message, ENCRYPT_HEADER, strlen( ENCRYPT_HEADER ) ) == 0 )
    @@ -228,26 +200,23 @@
    */
    char* mxit_encrypt_message( struct MXitSession* session, char* message )
    {
    + GString* raw_message = NULL;
    char exkey[512];
    - int i;
    - GString* raw_message = NULL;
    GString* encoded = NULL;
    gchar* base64;
    + 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 );
    - /* append encryption header to message data */
    - raw_message = g_string_sized_new( strlen( SECRET_HEADER ) + strlen( message ) );
    - g_string_append( raw_message, SECRET_HEADER );
    - g_string_append( raw_message, message );
    -
    - /* add ISO10126 padding */
    - padding_add( raw_message );
    -
    - /* encrypt each block */
    + /* AES encrypt each block */
    encoded = g_string_sized_new( raw_message->len );
    for ( i = 0; i < raw_message->len; i += 16 ) {
    char block[16];
    --- a/libpurple/protocols/mxit/cipher.h Mon Aug 15 19:24:16 2011 +0000
    +++ b/libpurple/protocols/mxit/cipher.h Mon Aug 15 20:10:35 2011 +0000
    @@ -1,7 +1,7 @@
    /*
    * MXit Protocol libPurple Plugin
    *
    - * -- user password encryption --
    + * -- encryption --
    *
    * Pieter Loubser <libpurple@mxit.com>
    *