source: protocols/msn/msn_util.c @ ffb6dea

  /********************************************************************\
  * BitlBee -- An IRC to other IM-networks gateway                     *
  *                                                                    *
  * Copyright 2002-2010 Wilmer van der Gaast and others                *
  \********************************************************************/

/* MSN module - Miscellaneous utilities                                 */

/*
  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
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License with
  the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
  if not, write to the Free Software Foundation, Inc., 59 Temple Place,
  Suite 330, Boston, MA  02111-1307  USA
*/

#include "nogaim.h"
#include "msn.h"
#include "md5.h"
#include <ctype.h>

int msn_write( struct im_connection *ic, char *s, int len )
{
        struct msn_data *md = ic->proto_data;
        int st;
        
        st = write( md->fd, s, len );
        if( st != len )
        {
                imcb_error( ic, "Short write() to main server" );
                imc_logout( ic, TRUE );
                return( 0 );
        }
        
        return( 1 );
}

int msn_logged_in( struct im_connection *ic )
{
        imcb_connected( ic );
        
        return( 0 );
}

int msn_buddy_list_add( struct im_connection *ic, char *list, char *who, char *realname_ )
{
        struct msn_data *md = ic->proto_data;
        char buf[1024], *realname;
        
        realname = msn_http_encode( realname_ );
        
        g_snprintf( buf, sizeof( buf ), "ADD %d %s %s %s\r\n", ++md->trId, list, who, realname );
        if( msn_write( ic, buf, strlen( buf ) ) )
        {
                g_free( realname );
                
                return( 1 );
        }
        
        g_free( realname );
        
        return( 0 );
}

int msn_buddy_list_remove( struct im_connection *ic, char *list, char *who )
{
        struct msn_data *md = ic->proto_data;
        char buf[1024];
        
        g_snprintf( buf, sizeof( buf ), "REM %d %s %s\r\n", ++md->trId, list, who );
        if( msn_write( ic, buf, strlen( buf ) ) )
                return( 1 );
        
        return( 0 );
}

struct msn_buddy_ask_data
{
        struct im_connection *ic;
        char *handle;
        char *realname;
};

static void msn_buddy_ask_yes( void *data )
{
        struct msn_buddy_ask_data *bla = data;
        
        msn_buddy_list_add( bla->ic, "AL", bla->handle, bla->realname );
        
        if( imcb_find_buddy( bla->ic, bla->handle ) == NULL )
                imcb_ask_add( bla->ic, bla->handle, NULL );
        
        g_free( bla->handle );
        g_free( bla->realname );
        g_free( bla );
}

static void msn_buddy_ask_no( void *data )
{
        struct msn_buddy_ask_data *bla = data;
        
        msn_buddy_list_add( bla->ic, "BL", bla->handle, bla->realname );
        
        g_free( bla->handle );
        g_free( bla->realname );
        g_free( bla );
}

void msn_buddy_ask( struct im_connection *ic, char *handle, char *realname )
{
        struct msn_buddy_ask_data *bla = g_new0( struct msn_buddy_ask_data, 1 );
        char buf[1024];
        
        bla->ic = ic;
        bla->handle = g_strdup( handle );
        bla->realname = g_strdup( realname );
        
        g_snprintf( buf, sizeof( buf ),
                    "The user %s (%s) wants to add you to his/her buddy list.",
                    handle, realname );
        imcb_ask( ic, buf, bla, msn_buddy_ask_yes, msn_buddy_ask_no );
}

char *msn_findheader( char *text, char *header, int len )
{
        int hlen = strlen( header ), i;
        char *ret;
        
        if( len == 0 )
                len = strlen( text );
        
        i = 0;
        while( ( i + hlen ) < len )
        {
                /* Maybe this is a bit over-commented, but I just hate this part... */
                if( g_strncasecmp( text + i, header, hlen ) == 0 )
                {
                        /* Skip to the (probable) end of the header */
                        i += hlen;
                        
                        /* Find the first non-[: \t] character */
                        while( i < len && ( text[i] == ':' || text[i] == ' ' || text[i] == '\t' ) ) i ++;
                        
                        /* Make sure we're still inside the string */
                        if( i >= len ) return( NULL );
                        
                        /* Save the position */
                        ret = text + i;
                        
                        /* Search for the end of this line */
                        while( i < len && text[i] != '\r' && text[i] != '\n' ) i ++;
                        
                        /* Make sure we're still inside the string */
                        if( i >= len ) return( NULL );
                        
                        /* Copy the found data */
                        return( g_strndup( ret, text + i - ret ) );
                }
                
                /* This wasn't the header we were looking for, skip to the next line. */
                while( i < len && ( text[i] != '\r' && text[i] != '\n' ) ) i ++;
                while( i < len && ( text[i] == '\r' || text[i] == '\n' ) ) i ++;
                
                /* End of headers? */
                if( ( i >= 4 && strncmp( text + i - 4, "\r\n\r\n", 4 ) == 0 ) ||
                    ( i >= 2 && ( strncmp( text + i - 2, "\n\n", 2 ) == 0 ||   
                                  strncmp( text + i - 2, "\r\r", 2 ) == 0 ) ) )
                {
                        break;
                }
        }
        
        return( NULL );
}

/* *NOT* thread-safe, but that's not a problem for now... */
char **msn_linesplit( char *line )
{
        static char **ret = NULL;
        static int size = 3;
        int i, n = 0;
        
        if( ret == NULL )
                ret = g_new0( char*, size );
        
        for( i = 0; line[i] && line[i] == ' '; i ++ );
        if( line[i] )
        {
                ret[n++] = line + i;
                for( i ++; line[i]; i ++ )
                {
                        if( line[i] == ' ' )
                                line[i] = 0;
                        else if( line[i] != ' ' && !line[i-1] )
                                ret[n++] = line + i;
                        
                        if( n >= size )
                                ret = g_renew( char*, ret, size += 2 );
                }
        }
        ret[n] = NULL;
        
        return( ret );
}

/* This one handles input from a MSN Messenger server. Both the NS and SB servers usually give
   commands, but sometimes they give additional data (payload). This function tries to handle
   this all in a nice way and send all data to the right places. */

/* Return values: -1: Read error, abort connection.
                   0: Command reported error; Abort *immediately*. (The connection does not exist anymore)
                   1: OK */

int msn_handler( struct msn_handler_data *h )
{
        int st;
        
        h->rxq = g_renew( char, h->rxq, h->rxlen + 1024 );
        st = read( h->fd, h->rxq + h->rxlen, 1024 );
        h->rxlen += st;
        
        if( st <= 0 )
                return( -1 );
        
        while( st )
        {
                int i;
                
                if( h->msglen == 0 )
                {
                        for( i = 0; i < h->rxlen; i ++ )
                        {
                                if( h->rxq[i] == '\r' || h->rxq[i] == '\n' )
                                {
                                        char *cmd_text, **cmd;
                                        int count;
                                        
                                        cmd_text = g_strndup( h->rxq, i );
                                        cmd = msn_linesplit( cmd_text );
                                        for( count = 0; cmd[count]; count ++ );
                                        st = h->exec_command( h->data, cmd, count );
                                        g_free( cmd_text );
                                        
                                        /* If the connection broke, don't continue. We don't even exist anymore. */
                                        if( !st )
                                                return( 0 );
                                        
                                        if( h->msglen )
                                                h->cmd_text = g_strndup( h->rxq, i );
                                        
                                        /* Skip to the next non-emptyline */
                                        while( i < h->rxlen && ( h->rxq[i] == '\r' || h->rxq[i] == '\n' ) ) i ++;
                                        
                                        break;
                                }
                        }
                        
                        /* If we reached the end of the buffer, there's still an incomplete command there.
                           Return and wait for more data. */
                        if( i == h->rxlen && h->rxq[i-1] != '\r' && h->rxq[i-1] != '\n' )
                                break;
                }
                else
                {
                        char *msg, **cmd;
                        int count;
                        
                        /* Do we have the complete message already? */
                        if( h->msglen > h->rxlen )
                                break;
                        
                        msg = g_strndup( h->rxq, h->msglen );
                        cmd = msn_linesplit( h->cmd_text );
                        for( count = 0; cmd[count]; count ++ );
                        
                        st = h->exec_message( h->data, msg, h->msglen, cmd, count );
                        g_free( msg );
                        g_free( h->cmd_text );
                        h->cmd_text = NULL;
                        
                        if( !st )
                                return( 0 );
                        
                        i = h->msglen;
                        h->msglen = 0;
                }
                
                /* More data after this block? */
                if( i < h->rxlen )
                {
                        char *tmp;
                        
                        tmp = g_memdup( h->rxq + i, h->rxlen - i );
                        g_free( h->rxq );
                        h->rxq = tmp;
                        h->rxlen -= i;
                        i = 0;
                }
                else
                /* If not, reset the rx queue and get lost. */
                {
                        g_free( h->rxq );
                        h->rxq = g_new0( char, 1 );
                        h->rxlen = 0;
                        return( 1 );
                }
        }
        
        return( 1 );
}

/* The difference between this function and the normal http_encode() function
   is that this one escapes every 7-bit ASCII character because this is said
   to avoid some lame server-side checks when setting a real-name. Also,
   non-ASCII characters are not escaped because MSN servers don't seem to
   appreciate that! */
char *msn_http_encode( const char *input )
{
        char *ret, *s;
        int i;
        
        ret = s = g_new0( char, strlen( input ) * 3 + 1 );
        for( i = 0; input[i]; i ++ )
                if( input[i] & 128 )
                {
                        *s = input[i];
                        s ++;
                }
                else
                {
                        g_snprintf( s, 4, "%%%02X", input[i] );
                        s += 3;
                }
        
        return ret;
}

void msn_msgq_purge( struct im_connection *ic, GSList **list )
{
        struct msn_message *m;
        GString *ret;
        GSList *l;
        
        l = *list;
        if( l == NULL )
                return;
        
        m = l->data;
        ret = g_string_sized_new( 1024 );
        g_string_printf( ret, "Warning: Cleaning up MSN (switchboard) connection with unsent "
                              "messages to %s:", m->who ? m->who : "unknown recipient" );
        
        while( l )
        {
                m = l->data;
                
                g_string_append_printf( ret, "\n%s", m->text );
                
                g_free( m->who );
                g_free( m->text );
                g_free( m );
                
                l = l->next;
        }
        g_slist_free( *list );
        *list = NULL;
        
        imcb_log( ic, "%s", ret->str );
        g_string_free( ret, TRUE );
}

unsigned int little_endian( unsigned int dw )
{
#if defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN
        return dw;
#else
        /* We're still not sure if this machine is big endian since the
           constants above are not that portable. Don't swap bytes, just
           force-compose a 32-bit little endian integer. */
        unsigned int ret = 0, i;
        char *dst = (char*) (&ret + 1);
        
        for (i = 0; i < 4; i ++)
        {
                *(--dst) = dw >> 24;
                dw <<= 8;
        }
        
        return ret;
#endif
}

/* Copied and heavily modified from http://tmsnc.sourceforge.net/chl.c */

char *msn_p11_challenge( char *challenge )
{
        char *output, buf[256];
        md5_state_t md5c;
        unsigned char md5Hash[16], *newHash;
        unsigned int *md5Parts, *chlStringParts, newHashParts[5];
        long long nHigh = 0, nLow = 0;
        int i, n;

        /* Create the MD5 hash */
        md5_init(&md5c);
        md5_append(&md5c, (unsigned char*) challenge, strlen(challenge));
        md5_append(&md5c, (unsigned char*) MSNP11_PROD_KEY, strlen(MSNP11_PROD_KEY));
        md5_finish(&md5c, md5Hash);

        /* Split it into four integers */
        md5Parts = (unsigned int *)md5Hash;
        for (i = 0; i < 4; i ++)
        {  
                md5Parts[i] = little_endian(md5Parts[i]);
                
                /* & each integer with 0x7FFFFFFF */
                /* and save one unmodified array for later */
                newHashParts[i] = md5Parts[i];
                md5Parts[i] &= 0x7FFFFFFF;
        }
        
        /* make a new string and pad with '0' */
        n = g_snprintf(buf, sizeof(buf)-5, "%s%s00000000", challenge, MSNP11_PROD_ID);
        /* truncate at an 8-byte boundary */
        buf[n&=~7] = '\0';
        
        /* split into integers */
        chlStringParts = (unsigned int *)buf;
        
        /* this is magic */
        for (i = 0; i < (n / 4) - 1; i += 2)
        {
                long long temp;

                chlStringParts[i]   = little_endian(chlStringParts[i]);
                chlStringParts[i+1] = little_endian(chlStringParts[i+1]);

                temp  = (md5Parts[0] * (((0x0E79A9C1 * (long long)chlStringParts[i]) % 0x7FFFFFFF)+nHigh) + md5Parts[1])%0x7FFFFFFF;
                nHigh = (md5Parts[2] * (((long long)chlStringParts[i+1]+temp) % 0x7FFFFFFF) + md5Parts[3]) % 0x7FFFFFFF;
                nLow  = nLow + nHigh + temp;
        }
        nHigh = (nHigh+md5Parts[1]) % 0x7FFFFFFF;
        nLow = (nLow+md5Parts[3]) % 0x7FFFFFFF;
        
        newHashParts[0] ^= nHigh;
        newHashParts[1] ^= nLow;
        newHashParts[2] ^= nHigh;
        newHashParts[3] ^= nLow;
        
        /* swap more bytes if big endian */
        for (i = 0; i < 4; i ++)
                newHashParts[i] = little_endian(newHashParts[i]); 
        
        /* make a string of the parts */
        newHash = (unsigned char *)newHashParts;
        
        /* convert to hexadecimal */
        output = g_new(char, 33);
        for (i = 0; i < 16; i ++)
                sprintf(output + i * 2, "%02x", newHash[i]);
        
        return output;
}