Function msEncryptStringWithKey

mapcrypto.c:304–355

 **********************************************************************/

void msEncryptStringWithKey(const unsigned char *key, const char *in, char *out)
{
    ms_uint32 v[4], w[4];
    const ms_uint32 *k;
    int last_block = MS_FALSE;
    
    /* Casting the key this way is safe only as long as longs are 4 bytes
     * on this platform */
    assert(sizeof(ms_uint32) == 4);
    k = (const ms_uint32 *) key;
    
    while(!last_block)
    {
        int i, j;
        /* encipher() takes v[2] (64 bits) as input. 
         * Copy bytes from in[] to the v[2] input array (pair of 4 bytes)
         * v[] is padded with zeros if string doesn't align with 8 bytes
         */
        v[0] = 0;
        v[1] = 0;
        for(i=0; !last_block && i<2; i++)
        {
            for(j=0; j<4; j++)
            {
                if (*in == '\0')
                {
                    last_block = MS_TRUE;
                    break;
                }

                v[i] |= *in << (j*8);
                in++;
            }
        }

        if (*in == '\0')
            last_block = MS_TRUE;

        /* Do the actual encryption */
        encipher(v, w, k);

        /* Append hex-encoded bytes to output, 4 bytes at a time */
        msHexEncode((unsigned char *)w, out, 4);
        out += 8;
        msHexEncode((unsigned char *)(w+1), out, 4);
        out += 8;

    }

    /* Make sure output is 0-terminated */
    *out = '\0';
}

/**********************************************************************
 *                        msDecryptStringWithKey()