drms.c

AAC编解码源码

/*****************************************************************************
 * drms.c : DRMS
 *****************************************************************************
 * Copyright (C) 2004 VideoLAN
 * $Id: drms.c,v 1.3 2004/01/11 15:52:18 menno Exp $
 *
 * Author: Jon Lech Johansen <[e-mail]>
 *
 * 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
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

#include <stdlib.h>                                      /* malloc(), free() */

#include "mp4ffint.h"

#ifdef ITUNES_DRM

#ifdef _WIN32
#include <tchar.h>
#include <shlobj.h>
#include <windows.h>
#endif

#include "drms.h"
#include "drmstables.h"

static __inline uint32_t U32_AT( void * _p )
{
    uint8_t * p = (uint8_t *)_p;
    return ( ((uint32_t)p[0] << 24) | ((uint32_t)p[1] << 16)
              | ((uint32_t)p[2] << 8) | p[3] );
}

#define TAOS_INIT( tmp, i ) \
    memset( tmp, 0, sizeof(tmp) ); \
    tmp[ i + 0 ] = 0x67452301; \
    tmp[ i + 1 ] = 0xEFCDAB89; \
    tmp[ i + 2 ] = 0x98BADCFE; \
    tmp[ i + 3 ] = 0x10325476;

#define ROR( x, n ) (((x) << (32-(n))) | ((x) >> (n)))

static void init_ctx( uint32_t *p_ctx, uint32_t *p_input )
{
    uint32_t i;
    uint32_t p_tmp[ 6 ];

    p_ctx[ 0 ] = sizeof(*p_input);

    memset( &p_ctx[ 1 + 4 ], 0, sizeof(*p_input) * 4 );
    memcpy( &p_ctx[ 1 + 0 ], p_input, sizeof(*p_input) * 4 );

    p_tmp[ 0 ] = p_ctx[ 1 + 3 ];

    for( i = 0; i < sizeof(p_drms_tab1)/sizeof(p_drms_tab1[ 0 ]); i++ )
    {
        p_tmp[ 0 ] = ROR( p_tmp[ 0 ], 8 );

        p_tmp[ 5 ] = p_drms_tab2[ (p_tmp[ 0 ] >> 24) & 0xFF ]
                   ^ ROR( p_drms_tab2[ (p_tmp[ 0 ] >> 16) & 0xFF ], 8 )
                   ^ ROR( p_drms_tab2[ (p_tmp[ 0 ] >> 8) & 0xFF ], 16 )
                   ^ ROR( p_drms_tab2[ p_tmp[ 0 ] & 0xFF ], 24 )
                   ^ p_drms_tab1[ i ]
                   ^ p_ctx[ 1 + ((i + 1) * 4) - 4 ];

        p_ctx[ 1 + ((i + 1) * 4) + 0 ] = p_tmp[ 5 ];
        p_tmp[ 5 ] ^= p_ctx[ 1 + ((i + 1) * 4) - 3 ];
        p_ctx[ 1 + ((i + 1) * 4) + 1 ] = p_tmp[ 5 ];
        p_tmp[ 5 ] ^= p_ctx[ 1 + ((i + 1) * 4) - 2 ];
        p_ctx[ 1 + ((i + 1) * 4) + 2 ] = p_tmp[ 5 ];
        p_tmp[ 5 ] ^= p_ctx[ 1 + ((i + 1) * 4) - 1 ];
        p_ctx[ 1 + ((i + 1) * 4) + 3 ] = p_tmp[ 5 ];

        p_tmp[ 0 ] = p_tmp[ 5 ];
    }

    memcpy( &p_ctx[ 1 + 64 ], &p_ctx[ 1 ], sizeof(*p_ctx) * 4 );

    for( i = 4; i < sizeof(p_drms_tab1); i++ )
    {
        p_tmp[ 2 ] = p_ctx[ 1 + 4 + (i - 4) ];

        p_tmp[ 0 ] = (((p_tmp[ 2 ] >> 7) & 0x01010101) * 27)
                   ^ ((p_tmp[ 2 ] & 0xFF7F7F7F) << 1);
        p_tmp[ 1 ] = (((p_tmp[ 0 ] >> 7) & 0x01010101) * 27)
                   ^ ((p_tmp[ 0 ] & 0xFF7F7F7F) << 1);
        p_tmp[ 4 ] = (((p_tmp[ 1 ] >> 7) & 0x01010101) * 27)
                   ^ ((p_tmp[ 1 ] & 0xFF7F7F7F) << 1);

        p_tmp[ 2 ] ^= p_tmp[ 4 ];

        p_tmp[ 3 ] = ROR( p_tmp[ 1 ] ^ p_tmp[ 2 ], 16 )
                   ^ ROR( p_tmp[ 0 ] ^ p_tmp[ 2 ], 8 )
                   ^ ROR( p_tmp[ 2 ], 24 );

        p_ctx[ 1 + 4 + 64 + (i - 4) ] = p_tmp[ 3 ] ^ p_tmp[ 4 ]
                                      ^ p_tmp[ 1 ] ^ p_tmp[ 0 ];
    }
}

static void ctx_xor( uint32_t *p_ctx, uint32_t *p_in, uint32_t *p_out,
                     uint32_t p_table1[ 256 ], uint32_t p_table2[ 256 ] )
{
    uint32_t i, x, y;
    uint32_t p_tmp1[ 4 ];
    uint32_t p_tmp2[ 4 ];

    i = p_ctx[ 0 ] * 4;

    p_tmp1[ 0 ] = p_ctx[ 1 + i + 24 ] ^ p_in[ 0 ];
    p_tmp1[ 1 ] = p_ctx[ 1 + i + 25 ] ^ p_in[ 1 ];
    p_tmp1[ 2 ] = p_ctx[ 1 + i + 26 ] ^ p_in[ 2 ];
    p_tmp1[ 3 ] = p_ctx[ 1 + i + 27 ] ^ p_in[ 3 ];

    i += 84;

#define XOR_ROR( p_table, p_tmp, i_ctx ) \
    p_table[ (p_tmp[ y > 2 ? y - 3 : y + 1 ] >> 24) & 0xFF ] \
    ^ ROR( p_table[ (p_tmp[ y > 1 ? y - 2 : y + 2 ] >> 16) & 0xFF ], 8 ) \
    ^ ROR( p_table[ (p_tmp[ y > 0 ? y - 1 : y + 3 ] >> 8) & 0xFF ], 16 ) \
    ^ ROR( p_table[ p_tmp[ y ] & 0xFF ], 24 ) \
    ^ p_ctx[ i_ctx ]

    for( x = 0; x < 1; x++ )
    {
        memcpy( p_tmp2, p_tmp1, sizeof(p_tmp1) );

        for( y = 0; y < 4; y++ )
        {
            p_tmp1[ y ] = XOR_ROR( p_table1, p_tmp2, 1 + i - x + y );
        }
    }

    for( ; x < 9; x++ )
    {
        memcpy( p_tmp2, p_tmp1, sizeof(p_tmp1) );

        for( y = 0; y < 4; y++ )
        {
            p_tmp1[ y ] = XOR_ROR( p_table1, p_tmp2,
                                   1 + i - x - ((x * 3) - y) );
        }
    }

    for( y = 0; y < 4; y++ )
    {
        p_out[ y ] = XOR_ROR( p_table2, p_tmp1,
                              1 + i - x - ((x * 3) - y) );
    }

#undef XOR_ROR
}

static void taos( uint32_t *p_buffer, uint32_t *p_input )
{
    uint32_t i;
    uint32_t x = 0;
    uint32_t p_tmp1[ 4 ];
    uint32_t p_tmp2[ 4 ];

    memcpy( p_tmp1, p_buffer, sizeof(p_tmp1) );

    p_tmp2[ 0 ] = ((~p_tmp1[ 1 ] & p_tmp1[ 3 ])
                |   (p_tmp1[ 2 ] & p_tmp1[ 1 ])) + p_input[ x ];
    p_tmp1[ 0 ] = p_tmp2[ 0 ] + p_tmp1[ 0 ] + p_drms_tab_taos[ x++ ];

    for( i = 0; i < 4; i++ )
    {
        p_tmp2[ 0 ] = ((p_tmp1[ 0 ] >> 0x19)
                    |  (p_tmp1[ 0 ] << 0x7)) + p_tmp1[ 1 ];
        p_tmp2[ 1 ] = ((~p_tmp2[ 0 ] & p_tmp1[ 2 ])
                    |   (p_tmp1[ 1 ] & p_tmp2[ 0 ])) + p_input[ x ];
        p_tmp2[ 1 ] += p_tmp1[ 3 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 3 ] = ((p_tmp2[ 1 ] >> 0x14)
                    |  (p_tmp2[ 1 ] << 0xC)) + p_tmp2[ 0 ];
        p_tmp2[ 1 ] = ((~p_tmp1[ 3 ] & p_tmp1[ 1 ])
                    |   (p_tmp1[ 3 ] & p_tmp2[ 0 ])) + p_input[ x ];
        p_tmp2[ 1 ] += p_tmp1[ 2 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 2 ] = ((p_tmp2[ 1 ] >> 0xF)
                    |  (p_tmp2[ 1 ] << 0x11)) + p_tmp1[ 3 ];
        p_tmp2[ 1 ] = ((~p_tmp1[ 2 ] & p_tmp2[ 0 ])
                    |   (p_tmp1[ 3 ] & p_tmp1[ 2 ])) + p_input[ x ];
        p_tmp2[ 2 ] = p_tmp2[ 1 ] + p_tmp1[ 1 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 1 ] = ((p_tmp2[ 2 ] << 0x16)
                    |  (p_tmp2[ 2 ] >> 0xA)) + p_tmp1[ 2 ];
        if( i == 3 )
        {
            p_tmp2[ 1 ] = ((~p_tmp1[ 3 ] & p_tmp1[ 2 ])
                        |   (p_tmp1[ 3 ] & p_tmp1[ 1 ])) + p_input[ 1 ];
        }
        else
        {
            p_tmp2[ 1 ] = ((~p_tmp1[ 1 ] & p_tmp1[ 3 ])
                        |   (p_tmp1[ 2 ] & p_tmp1[ 1 ])) + p_input[ x ];
        }
        p_tmp1[ 0 ] = p_tmp2[ 0 ] + p_tmp2[ 1 ] + p_drms_tab_taos[ x++ ];
    }

    for( i = 0; i < 4; i++ )
    {
        uint8_t p_table[ 4 ][ 4 ] =
        {
            {  6, 11,  0,  5 },
            { 10, 15,  4,  9 },
            { 14,  3,  8, 13 },
            {  2,  7, 12,  5 }
        };

        p_tmp2[ 0 ] = ((p_tmp1[ 0 ] >> 0x1B)
                    |  (p_tmp1[ 0 ] << 0x5)) + p_tmp1[ 1 ];
        p_tmp2[ 1 ] = ((~p_tmp1[ 2 ] & p_tmp1[ 1 ])
                    |   (p_tmp1[ 2 ] & p_tmp2[ 0 ]))
                    +   p_input[ p_table[ i ][ 0 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 3 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 3 ] = ((p_tmp2[ 1 ] >> 0x17)
                    |  (p_tmp2[ 1 ] << 0x9)) + p_tmp2[ 0 ];
        p_tmp2[ 1 ] = ((~p_tmp1[ 1 ] & p_tmp2[ 0 ])
                    |   (p_tmp1[ 3 ] & p_tmp1[ 1 ]))
                    +   p_input[ p_table[ i ][ 1 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 2 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 2 ] = ((p_tmp2[ 1 ] >> 0x12)
                    |  (p_tmp2[ 1 ] << 0xE)) + p_tmp1[ 3 ];
        p_tmp2[ 1 ] = ((~p_tmp2[ 0 ] & p_tmp1[ 3 ])
                    |   (p_tmp1[ 2 ] & p_tmp2[ 0 ]))
                    +   p_input[ p_table[ i ][ 2 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 1 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 1 ] = ((p_tmp2[ 1 ] << 0x14)
                    |  (p_tmp2[ 1 ] >> 0xC)) + p_tmp1[ 2 ];
        if( i == 3 )
        {
            p_tmp2[ 1 ] = (p_tmp1[ 3 ] ^ p_tmp1[ 2 ] ^ p_tmp1[ 1 ])
                        + p_input[ p_table[ i ][ 3 ] ];
        }
        else
        {
            p_tmp2[ 1 ] = ((~p_tmp1[ 3 ] & p_tmp1[ 2 ])
                        |   (p_tmp1[ 3 ] & p_tmp1[ 1 ]))
                        +   p_input[ p_table[ i ][ 3 ] ];
        }
        p_tmp1[ 0 ] = p_tmp2[ 0 ] + p_tmp2[ 1 ] + p_drms_tab_taos[ x++ ];
    }

    for( i = 0; i < 4; i++ )
    {
        uint8_t p_table[ 4 ][ 4 ] =
        {
            {  8, 11, 14,  1 },
            {  4,  7, 10, 13 },
            {  0,  3,  6,  9 },
            { 12, 15,  2,  0 }
        };

        p_tmp2[ 0 ] = ((p_tmp1[ 0 ] >> 0x1C)
                    |  (p_tmp1[ 0 ] << 0x4)) + p_tmp1[ 1 ];
        p_tmp2[ 1 ] = (p_tmp1[ 2 ] ^ p_tmp1[ 1 ] ^ p_tmp2[ 0 ])
                    + p_input[ p_table[ i ][ 0 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 3 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 3 ] = ((p_tmp2[ 1 ] >> 0x15)
                    |  (p_tmp2[ 1 ] << 0xB)) + p_tmp2[ 0 ];
        p_tmp2[ 1 ] = (p_tmp1[ 3 ] ^ p_tmp1[ 1 ] ^ p_tmp2[ 0 ])
                    + p_input[ p_table[ i ][ 1 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 2 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 2 ] = ((p_tmp2[ 1 ] >> 0x10)
                    |  (p_tmp2[ 1 ] << 0x10)) + p_tmp1[ 3 ];
        p_tmp2[ 1 ] = (p_tmp1[ 3 ] ^ p_tmp1[ 2 ] ^ p_tmp2[ 0 ])
                    + p_input[ p_table[ i ][ 2 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 1 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 1 ] = ((p_tmp2[ 1 ] << 0x17)
                    |  (p_tmp2[ 1 ] >> 0x9)) + p_tmp1[ 2 ];
        if( i == 3 )
        {
            p_tmp2[ 1 ] = ((~p_tmp1[ 3 ] | p_tmp1[ 1 ]) ^ p_tmp1[ 2 ])
                        +   p_input[ p_table[ i ][ 3 ] ];
        }
        else
        {
            p_tmp2[ 1 ] = (p_tmp1[ 3 ] ^ p_tmp1[ 2 ] ^ p_tmp1[ 1 ])
                        + p_input[ p_table[ i ][ 3 ] ];
        }
        p_tmp1[ 0 ] = p_tmp2[ 0 ] + p_tmp2[ 1 ] + p_drms_tab_taos[ x++ ];
    }

    for( i = 0; i < 4; i++ )
    {
        uint8_t p_table[ 4 ][ 4 ] =
        {
            {  7, 14,  5, 12 },
            {  3, 10,  1,  8 },
            { 15,  6, 13,  4 },
            { 11,  2,  9,  0 }
        };

        p_tmp2[ 0 ] = ((p_tmp1[ 0 ] >> 0x1A)
                    |  (p_tmp1[ 0 ] << 0x6)) + p_tmp1[ 1 ];
        p_tmp2[ 1 ] = ((~p_tmp1[ 2 ] | p_tmp2[ 0 ]) ^ p_tmp1[ 1 ])
                    +   p_input[ p_table[ i ][ 0 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 3 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 3 ] = ((p_tmp2[ 1 ] >> 0x16)
                    |  (p_tmp2[ 1 ] << 0xA)) + p_tmp2[ 0 ];
        p_tmp2[ 1 ] = ((~p_tmp1[ 1 ] | p_tmp1[ 3 ]) ^ p_tmp2[ 0 ])
                    +   p_input[ p_table[ i ][ 1 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 2 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 2 ] = ((p_tmp2[ 1 ] >> 0x11)
                    |  (p_tmp2[ 1 ] << 0xF)) + p_tmp1[ 3 ];
        p_tmp2[ 1 ] = ((~p_tmp2[ 0 ] | p_tmp1[ 2 ]) ^ p_tmp1[ 3 ])
                    +   p_input[ p_table[ i ][ 2 ] ];
        p_tmp2[ 1 ] += p_tmp1[ 1 ] + p_drms_tab_taos[ x++ ];

        p_tmp1[ 1 ] = ((p_tmp2[ 1 ] << 0x15)
                    |  (p_tmp2[ 1 ] >> 0xB)) + p_tmp1[ 2 ];

        if( i < 3 )
        {
            p_tmp2[ 1 ] = ((~p_tmp1[ 3 ] | p_tmp1[ 1 ]) ^ p_tmp1[ 2 ])
                        +   p_input[ p_table[ i ][ 3 ] ];
            p_tmp1[ 0 ] = p_tmp2[ 0 ] + p_tmp2[ 1 ] + p_drms_tab_taos[ x++ ];
        }
    }

    p_buffer[ 0 ] += p_tmp2[ 0 ];
    p_buffer[ 1 ] += p_tmp1[ 1 ];
    p_buffer[ 2 ] += p_tmp1[ 2 ];
    p_buffer[ 3 ] += p_tmp1[ 3 ];
}

static void taos_add1( uint32_t *p_buffer,
                       uint8_t *p_in, uint32_t i_len )
{
    uint32_t i;
    uint32_t x, y;
    uint32_t p_tmp[ 16 ];
    uint32_t i_offset = 0;

    x = p_buffer[ 6 ] & 63;
    y = 64 - x;

    p_buffer[ 6 ] += i_len;

    if( i_len < y )
    {
        memcpy( &((uint8_t *)p_buffer)[ 48 + x ], p_in, i_len );
    }
    else
    {
        if( x )
        {
            memcpy( &((uint8_t *)p_buffer)[ 48 + x ], p_in, y );
            taos( &p_buffer[ 8 ], &p_buffer[ 12 ] );
            i_offset = y;
            i_len -= y;
        }

        if( i_len >= 64 )
        {
            for( i = 0; i < i_len / 64; i++ )
            {
                memcpy( p_tmp, &p_in[ i_offset ], sizeof(p_tmp) );
                taos( &p_buffer[ 8 ], p_tmp );
                i_offset += 64;
                i_len -= 64;
            }
        }

        if( i_len )
        {
            memcpy( &p_buffer[ 12 ], &p_in[ i_offset ], i_len );
        }
    }
}

static void taos_end1( uint32_t *p_buffer, uint32_t *p_out )
{
    uint32_t x, y;

    x = p_buffer[ 6 ] & 63;
    y = 63 - x;

    ((uint8_t *)p_buffer)[ 48 + x++ ] = 128;

    if( y < 8 )
    {
        memset( &((uint8_t *)p_buffer)[ 48 + x ], 0, y );
        taos( &p_buffer[ 8 ], &p_buffer[ 12 ] );
        y = 64;
        x = 0;
    }

    memset( &((uint8_t *)p_buffer)[ 48 + x ], 0, y );

    p_buffer[ 26 ] = p_buffer[ 6 ] * 8;
    p_buffer[ 27 ] = p_buffer[ 6 ] >> 29;
    taos( &p_buffer[ 8 ], &p_buffer[ 12 ] );

    memcpy( p_out, &p_buffer[ 8 ], sizeof(*p_out) * 4 );
}

static void taos_add2( uint32_t *p_buffer, uint8_t *p_in, uint32_t i_len )
{
    uint32_t i, x;
    uint32_t p_tmp[ 16 ];

    x = (p_buffer[ 0 ] / 8) & 63;
    i = p_buffer[ 0 ] + i_len * 8;

    if( i < p_buffer[ 0 ] )
    {
        p_buffer[ 1 ] += 1;
    }

    p_buffer[ 0 ] = i;
    p_buffer[ 1 ] += i_len >> 29;

    for( i = 0; i < i_len; i++ )
    {
        ((uint8_t *)p_buffer)[ 24 + x++ ] = p_in[ i ];

        if( x != 64 )
            continue;

        memcpy( p_tmp, &p_buffer[ 6 ], sizeof(p_tmp) );
        taos( &p_buffer[ 2 ], p_tmp );
    }
}

static void taos_add2e( uint32_t *p_buffer, uint32_t *p_in, uint32_t i_len )
{
    uint32_t i, x, y;
    uint32_t p_tmp[ 32 ];

    if( i_len )
    {
        for( x = i_len; x; x -= y )
        {
            y = x > 32 ? 32 : x;

            for( i = 0; i < y; i++ )
            {
                p_tmp[ i ] = U32_AT(&p_in[ i ]);
            }
        }
    }

    taos_add2( p_buffer, (uint8_t *)p_tmp, i_len * sizeof(p_tmp[ 0 ]) );
}

static void taos_end2( uint32_t *p_buffer )
{
    uint32_t x;
    uint32_t p_tmp[ 16 ];

    p_tmp[ 14 ] = p_buffer[ 0 ];
    p_tmp[ 15 ] = p_buffer[ 1 ];

    x = (p_buffer[ 0 ] / 8) & 63;

    taos_add2( p_buffer, p_drms_tab_tend, 56 - x );
    memcpy( p_tmp, &p_buffer[ 6 ], 56 );
    taos( &p_buffer[ 2 ], p_tmp );
    memcpy( &p_buffer[ 22 ], &p_buffer[ 2 ], sizeof(*p_buffer) * 4 );
}

static void taos_add3( uint32_t *p_buffer, uint8_t *p_key, uint32_t i_len )
{
    uint32_t x, y;
    uint32_t i = 0;

    x = (p_buffer[ 4 ] / 8) & 63;
    p_buffer[ 4 ] += i_len * 8;

    if( p_buffer[ 4 ] < i_len * 8 )
        p_buffer[ 5 ] += 1;

    p_buffer[ 5 ] += i_len >> 29;

    y = 64 - x;

    if( i_len >= y )
    {
        memcpy( &((uint8_t *)p_buffer)[ 24 + x ], p_key, y );
        taos( p_buffer, &p_buffer[ 6 ] );

        i = y;
        y += 63;

        if( y < i_len )
        {
            for( ; y < i_len; y += 64, i += 64 )
            {
                taos( p_buffer, (uint32_t *)&p_key[y - 63] );
            }
        }
        else
        {
            x = 0;
        }
    }

    memcpy( &((uint8_t *)p_buffer)[ 24 + x ], &p_key[ i ], i_len - i );
}