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rizin/libr/crypto/p/crypto_cps2.c
pancake 1fa04d98c3 Fix for crypto.cps2
2016-08-03 14:07:03 +02:00

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/* radare - LGPL - Copyright 2016 - pancake */
/* XXX this must be specified by the user/rom? */
#define UPPER_LIMIT 0xffffff
#define BIT(x,n) (((x)>>(n))&1)
#define BITSWAP8(val,B7,B6,B5,B4,B3,B2,B1,B0) \
((BIT(val,B7) << 7) | (BIT(val,B6) << 6) | (BIT(val,B5) << 5) | (BIT(val,B4) << 4) | \
(BIT(val,B3) << 3) | (BIT(val,B2) << 2) | (BIT(val,B1) << 1) | (BIT(val,B0) << 0))
// license:BSD-3-Clause
// copyright-holders:Paul Leaman, Andreas Naive, Nicola Salmoria,Charles MacDonald
/******************************************************************************
CPS-2 Encryption
All credit goes to Andreas Naive for breaking the encryption algorithm.
Code by Nicola Salmoria.
Thanks to Charles MacDonald and Razoola for extracting the data from the hardware.
The encryption only affects opcodes, not data.
It consists of two 4-round Feistel networks (FN) and involves both
the 16-bit opcode and the low 16 bits of the address.
Let be:
E = 16-bit ciphertext
A = 16-bit address
K = 64-bit key
D = 16-bit plaintext
y = FN1(x,k) = function describing the first Feistel network (x,y = 16 bit, k = 64 bit)
y = FN2(x,k) = function describing the second Feistel network (x,y = 16 bit, k = 64 bit)
y = EX(x) = fixed function that expands the 16-bit x to the 64-bit y
Then the cipher can be described as:
D = FN2( E, K XOR EX( FN1(A, K ) ) )
Each round of the Feistel networks consists of four substitution boxes. The boxes
have 6 inputs and 2 outputs. Usually the input is the XOR of a data bit and a key
bit, however in some cases only the key is used.
(TODO-notes about accuracy of s-boxes)
The s-boxes were chosen in order to use an empty key (all FF) for the dead board.
Also, the hardware has different watchdog opcodes and address range (see below)
which are stored in the battery backed RAM. There doesn't appear to be any relation
between those and the 64-bit encryption key, so they probably use an additional
64 bits of battery-backed RAM.
First FN:
B(0 1 3 5 8 9 11 12) A(10 4 6 7 2 13 15 14)
L0 R0
| |
XOR<-----------[F1]<------------|
| |
R1 L1
| |
|------------>[F2]----------->XOR
| |
L2 R2
| |
XOR<-----------[F3]<------------|
| |
R3 L3
| |
|------------>[F4]----------->XOR
| |
L4 R4
(10 4 6 7 2 13 15 14) (0 1 3 5 8 9 11 12)
Second FN:
B(3 5 9 10 8 15 12 11) A(6 0 2 13 1 4 14 7)
L0 R0
| |
XOR<-----------[F1]<------------|
| |
R1 L1
| |
|------------>[F2]----------->XOR
| |
L2 R2
| |
XOR<-----------[F3]<------------|
| |
R3 L3
| |
|------------>[F4]----------->XOR
| |
L4 R4
(6 0 2 13 1 4 14 7) (3 5 9 10 8 15 12 11)
******************************************************************************
Some Encryption notes.
----------------------
Address range.
The encryption does _not_ cover the entire address space. The range covered
differs per game.
Encryption Watchdog.
The CPS2 system has a watchdog system that will disable the decryption
of data if the watchdog isn't triggered at least once every few seconds.
The trigger varies from game to game (some games do use the same) and is
basically a 68000 opcode/s instruction. The instruction is the same for
all regions of the game. The watchdog instructions are listed alongside
the decryption keys.
*******************************************************************************/
#include <r_crypto.h>
/******************************************************************************/
static const int fn1_groupA[8] = { 10, 4, 6, 7, 2, 13, 15, 14 };
static const int fn1_groupB[8] = { 0, 1, 3, 5, 8, 9, 11, 12 };
static const int fn2_groupA[8] = { 6, 0, 2, 13, 1, 4, 14, 7 };
static const int fn2_groupB[8] = { 3, 5, 9, 10, 8, 15, 12, 11 };
/******************************************************************************/
// The order of the input and output bits in the s-boxes is arbitrary.
// Each s-box can be XORed with an arbitrary vale in range 0-3 (but the same value
// must be used for the corresponding output bits in f1 and f3 or in f2 and f4)
struct sbox {
const ut8 table[64];
const int inputs[6]; // positions of the inputs bits, -1 means no input except from key
const int outputs[2]; // positions of the output bits
};
// the above struct better defines how the hardware works, however
// to speed up the decryption at run time we convert it to the
// following one
struct optimised_sbox {
ut8 input_lookup[256];
ut8 output[64];
};
static const struct sbox fn1_r1_boxes[4] = {
{ // subkey bits 0- 5
{
0,2,2,0,1,0,1,1,3,2,0,3,0,3,1,2,1,1,1,2,1,3,2,2,2,3,3,2,1,1,1,2,
2,2,0,0,3,1,3,1,1,1,3,0,0,1,0,0,1,2,2,1,2,3,2,2,2,3,1,3,2,0,1,3,
},
{ 3, 4, 5, 6, -1, -1 },
{ 3, 6 }
},
{ // subkey bits 6-11
{
3,0,2,2,2,1,1,1,1,2,1,0,0,0,2,3,2,3,1,3,0,0,0,2,1,2,2,3,0,3,3,3,
0,1,3,2,3,3,3,1,1,1,1,2,0,1,2,1,3,2,3,1,1,3,2,2,2,3,1,3,2,3,0,0,
},
{ 0, 1, 2, 4, 7, -1 },
{ 2, 7 }
},
{ // subkey bits 12-17
{
3,0,3,1,1,0,2,2,3,1,2,0,3,3,2,3,0,1,0,1,2,3,0,2,0,2,0,1,0,0,1,0,
2,3,1,2,1,0,2,0,2,1,0,1,0,2,1,0,3,1,2,3,1,3,1,1,1,2,0,2,2,0,0,0,
},
{ 0, 1, 2, 3, 6, 7 },
{ 0, 1 }
},
{ // subkey bits 18-23
{
3,2,0,3,0,2,2,1,1,2,3,2,1,3,2,1,2,2,1,3,3,2,1,0,1,0,1,3,0,0,0,2,
2,1,0,1,0,1,0,1,3,1,1,2,2,3,2,0,3,3,2,0,2,1,3,3,0,0,3,0,1,1,3,3,
},
{ 0, 1, 3, 5, 6, 7 },
{ 4, 5 }
},
};
static const struct sbox fn1_r2_boxes[4] = {
{ // subkey bits 24-29
{
3,3,2,0,3,0,3,1,0,3,0,1,0,2,1,3,1,3,0,3,3,1,3,3,3,2,3,2,2,3,1,2,
0,2,2,1,0,1,2,0,3,3,0,1,3,2,1,2,3,0,1,3,0,1,2,2,1,2,1,2,0,1,3,0,
},
{ 0, 1, 2, 3, 6, -1 },
{ 1, 6 }
},
{ // subkey bits 30-35
{
1,2,3,2,1,3,0,1,1,0,2,0,0,2,3,2,3,3,0,1,2,2,1,0,1,0,1,2,3,2,1,3,
2,2,2,0,1,0,2,3,2,1,2,1,2,1,0,3,0,1,2,3,1,2,1,3,2,0,3,2,3,0,2,0,
},
{ 2, 4, 5, 6, 7, -1 },
{ 5, 7 }
},
{ // subkey bits 36-41
{
0,1,0,2,1,1,0,1,0,2,2,2,1,3,0,0,1,1,3,1,2,2,2,3,1,0,3,3,3,2,2,2,
1,1,3,0,3,1,3,0,1,3,3,2,1,1,0,0,1,2,2,2,1,1,1,2,2,0,0,3,2,3,1,3,
},
{ 1, 2, 3, 4, 5, 7 },
{ 0, 3 }
},
{ // subkey bits 42-47
{
2,1,0,3,3,3,2,0,1,2,1,1,1,0,3,1,1,3,3,0,1,2,1,0,0,0,3,0,3,0,3,0,
1,3,3,3,0,3,2,0,2,1,2,2,2,1,1,3,0,1,0,1,0,1,1,1,1,3,1,0,1,2,3,3,
},
{ 0, 1, 3, 4, 6, 7 },
{ 2, 4 }
},
};
static const struct sbox fn1_r3_boxes[4] = {
{ // subkey bits 48-53
{
0,0,0,3,3,1,1,0,2,0,2,0,0,0,3,2,0,1,2,3,2,2,1,0,3,0,0,0,0,0,2,3,
3,0,0,1,1,2,3,3,0,1,3,2,0,1,3,3,2,0,0,1,0,2,0,0,0,3,1,3,3,3,3,3,
},
{ 0, 1, 5, 6, 7, -1 },
{ 0, 5 }
},
{ // subkey bits 54-59
{
2,3,2,3,0,2,3,0,2,2,3,0,3,2,0,2,1,0,2,3,1,1,1,0,0,1,0,2,1,2,2,1,
3,0,2,1,2,3,3,0,3,2,3,1,0,2,1,0,1,2,2,3,0,2,1,3,1,3,0,2,1,1,1,3,
},
{ 2, 3, 4, 6, 7, -1 },
{ 6, 7 }
},
{ // subkey bits 60-65
{
3,0,2,1,1,3,1,2,2,1,2,2,2,0,0,1,2,3,1,0,2,0,0,2,3,1,2,0,0,0,3,0,
2,1,1,2,0,0,1,2,3,1,1,2,0,1,3,0,3,1,1,0,0,2,3,0,0,0,0,3,2,0,0,0,
},
{ 0, 2, 3, 4, 5, 6 },
{ 1, 4 }
},
{ // subkey bits 66-71
{
0,1,0,0,2,1,3,2,3,3,2,1,0,1,1,1,1,1,0,3,3,1,1,0,0,2,2,1,0,3,3,2,
1,3,3,0,3,0,2,1,1,2,3,2,2,2,1,0,0,3,3,3,2,2,3,1,0,2,3,0,3,1,1,0,
},
{ 0, 1, 2, 3, 5, 7 },
{ 2, 3 }
},
};
static const struct sbox fn1_r4_boxes[4] = {
{ // subkey bits 72-77
{
1,1,1,1,1,0,1,3,3,2,3,0,1,2,0,2,3,3,0,1,2,1,2,3,0,3,2,3,2,0,1,2,
0,1,0,3,2,1,3,2,3,1,2,3,2,0,1,2,2,0,0,0,2,1,3,0,3,1,3,0,1,3,3,0,
},
{ 1, 2, 3, 4, 5, 7 },
{ 0, 4 }
},
{ // subkey bits 78-83
{
3,0,0,0,0,1,0,2,3,3,1,3,0,3,1,2,2,2,3,1,0,0,2,0,1,0,2,2,3,3,0,0,
1,1,3,0,2,3,0,3,0,3,0,2,0,2,0,1,0,3,0,1,3,1,1,0,0,1,3,3,2,2,1,0,
},
{ 0, 1, 2, 3, 5, 6 },
{ 1, 3 }
},
{ // subkey bits 84-89
{
0,1,1,2,0,1,3,1,2,0,3,2,0,0,3,0,3,0,1,2,2,3,3,2,3,2,0,1,0,0,1,0,
3,0,2,3,0,2,2,2,1,1,0,2,2,0,0,1,2,1,1,1,2,3,0,3,1,2,3,3,1,1,3,0,
},
{ 0, 2, 4, 5, 6, 7 },
{ 2, 6 }
},
{ // subkey bits 90-95
{
0,1,2,2,0,1,0,3,2,2,1,1,3,2,0,2,0,1,3,3,0,2,2,3,3,2,0,0,2,1,3,3,
1,1,1,3,1,2,1,1,0,3,3,2,3,2,3,0,3,1,0,0,3,0,0,0,2,2,2,1,2,3,0,0,
},
{ 0, 1, 3, 4, 6, 7 },
{ 5, 7 }
},
};
/******************************************************************************/
static const struct sbox fn2_r1_boxes[4] = {
{ // subkey bits 0- 5
{
2,0,2,0,3,0,0,3,1,1,0,1,3,2,0,1,2,0,1,2,0,2,0,2,2,2,3,0,2,1,3,0,
0,1,0,1,2,2,3,3,0,3,0,2,3,0,1,2,1,1,0,2,0,3,1,1,2,2,1,3,1,1,3,1,
},
{ 0, 3, 4, 5, 7, -1 },
{ 6, 7 }
},
{ // subkey bits 6-11
{
1,1,0,3,0,2,0,1,3,0,2,0,1,1,0,0,1,3,2,2,0,2,2,2,2,0,1,3,3,3,1,1,
1,3,1,3,2,2,2,2,2,2,0,1,0,1,1,2,3,1,1,2,0,3,3,3,2,2,3,1,1,1,3,0,
},
{ 1, 2, 3, 4, 6, -1 },
{ 3, 5 }
},
{ // subkey bits 12-17
{
1,0,2,2,3,3,3,3,1,2,2,1,0,1,2,1,1,2,3,1,2,0,0,1,2,3,1,2,0,0,0,2,
2,0,1,1,0,0,2,0,0,0,2,3,2,3,0,1,3,0,0,0,2,3,2,0,1,3,2,1,3,1,1,3,
},
{ 1, 2, 4, 5, 6, 7 },
{ 1, 4 }
},
{ // subkey bits 18-23
{
1,3,3,0,3,2,3,1,3,2,1,1,3,3,2,1,2,3,0,3,1,0,0,2,3,0,0,0,3,3,0,1,
2,3,0,0,0,1,2,1,3,0,0,1,0,2,2,2,3,3,1,2,1,3,0,0,0,3,0,1,3,2,2,0,
},
{ 0, 2, 3, 5, 6, 7 },
{ 0, 2 }
},
};
static const struct sbox fn2_r2_boxes[4] = {
{ // subkey bits 24-29
{
3,1,3,0,3,0,3,1,3,0,0,1,1,3,0,3,1,1,0,1,2,3,2,3,3,1,2,2,2,0,2,3,
2,2,2,1,1,3,3,0,3,1,2,1,1,1,0,2,0,3,3,0,0,2,0,0,1,1,2,1,2,1,1,0,
},
{ 0, 2, 4, 6, -1, -1 },
{ 4, 6 }
},
{ // subkey bits 30-35
{
0,3,0,3,3,2,1,2,3,1,1,1,2,0,2,3,0,3,1,2,2,1,3,3,3,2,1,2,2,0,1,0,
2,3,0,1,2,0,1,1,2,0,2,1,2,0,2,3,3,1,0,2,3,3,0,3,1,1,3,0,0,1,2,0,
},
{ 1, 3, 4, 5, 6, 7 },
{ 0, 3 }
},
{ // subkey bits 36-41
{
0,0,2,1,3,2,1,0,1,2,2,2,1,1,0,3,1,2,2,3,2,1,1,0,3,0,0,1,1,2,3,1,
3,3,2,2,1,0,1,1,1,2,0,1,2,3,0,3,3,0,3,2,2,0,2,2,1,2,3,2,1,0,2,1,
},
{ 0, 1, 3, 4, 5, 7 },
{ 1, 7 }
},
{ // subkey bits 42-47
{
0,2,1,2,0,2,2,0,1,3,2,0,3,2,3,0,3,3,2,3,1,2,3,1,2,2,0,0,2,2,1,2,
2,3,3,3,1,1,0,0,0,3,2,0,3,2,3,1,1,1,1,0,1,0,1,3,0,0,1,2,2,3,2,0,
},
{ 1, 2, 3, 5, 6, 7 },
{ 2, 5 }
},
};
static const struct sbox fn2_r3_boxes[4] = {
{ // subkey bits 48-53
{
2,1,2,1,2,3,1,3,2,2,1,3,3,0,0,1,0,2,0,3,3,1,0,0,1,1,0,2,3,2,1,2,
1,1,2,1,1,3,2,2,0,2,2,3,3,3,2,0,0,0,0,0,3,3,3,0,1,2,1,0,2,3,3,1,
},
{ 2, 3, 4, 6, -1, -1 },
{ 3, 5 }
},
{ // subkey bits 54-59
{
3,2,3,3,1,0,3,0,2,0,1,1,1,0,3,0,3,1,3,1,0,1,2,3,2,2,3,2,0,1,1,2,
3,0,0,2,1,0,0,2,2,0,1,0,0,2,0,0,1,3,1,3,2,0,3,3,1,0,2,2,2,3,0,0,
},
{ 0, 1, 3, 5, 7, -1 },
{ 0, 2 }
},
{ // subkey bits 60-65
{
2,2,1,0,2,3,3,0,0,0,1,3,1,2,3,2,2,3,1,3,0,3,0,3,3,2,2,1,0,0,0,2,
1,2,2,2,0,0,1,2,0,1,3,0,2,3,2,1,3,2,2,2,3,1,3,0,2,0,2,1,0,3,3,1,
},
{ 0, 1, 2, 3, 5, 7 },
{ 1, 6 }
},
{ // subkey bits 66-71
{
1,2,3,2,0,2,1,3,3,1,0,1,1,2,2,0,0,1,1,1,2,1,1,2,0,1,3,3,1,1,1,2,
3,3,1,0,2,1,1,1,2,1,0,0,2,2,3,2,3,2,2,0,2,2,3,3,0,2,3,0,2,2,1,1,
},
{ 0, 2, 4, 5, 6, 7 },
{ 4, 7 }
},
};
static const struct sbox fn2_r4_boxes[4] = {
{ // subkey bits 72-77
{
2,0,1,1,2,1,3,3,1,1,1,2,0,1,0,2,0,1,2,0,2,3,0,2,3,3,2,2,3,2,0,1,
3,0,2,0,2,3,1,3,2,0,0,1,1,2,3,1,1,1,0,1,2,0,3,3,1,1,1,3,3,1,1,0,
},
{ 0, 1, 3, 6, 7, -1 },
{ 0, 3 }
},
{ // subkey bits 78-83
{
1,2,2,1,0,3,3,1,0,2,2,2,1,0,1,0,1,1,0,1,0,2,1,0,2,1,0,2,3,2,3,3,
2,2,1,2,2,3,1,3,3,3,0,1,0,1,3,0,0,0,1,2,0,3,3,2,3,2,1,3,2,1,0,2,
},
{ 0, 1, 2, 4, 5, 6 },
{ 4, 7 }
},
{ // subkey bits 84-89
{
2,3,2,1,3,2,3,0,0,2,1,1,0,0,3,2,3,1,0,1,2,2,2,1,3,2,2,1,0,2,1,2,
0,3,1,0,0,3,1,1,3,3,2,0,1,0,1,3,0,0,1,2,1,2,3,2,1,0,0,3,2,1,1,3,
},
{ 0, 2, 3, 4, 5, 7 },
{ 1, 2 }
},
{ // subkey bits 90-95
{
2,0,0,3,2,2,2,1,3,3,1,1,2,0,0,3,1,0,3,2,1,0,2,0,3,2,2,3,2,0,3,0,
1,3,0,2,2,1,3,3,0,1,0,3,1,1,3,2,0,3,0,2,3,2,1,3,2,3,0,0,1,3,2,1,
},
{ 2, 3, 4, 5, 6, 7 },
{ 5, 6 }
},
};
/******************************************************************************/
static ut8 fn(ut8 in, const struct optimised_sbox *sboxes, ut32 key) {
const struct optimised_sbox *sbox1 = &sboxes[0];
const struct optimised_sbox *sbox2 = &sboxes[1];
const struct optimised_sbox *sbox3 = &sboxes[2];
const struct optimised_sbox *sbox4 = &sboxes[3];
return
sbox1->output[sbox1->input_lookup[in] ^ ((key >> 0) & 0x3f)] |
sbox2->output[sbox2->input_lookup[in] ^ ((key >> 6) & 0x3f)] |
sbox3->output[sbox3->input_lookup[in] ^ ((key >> 12) & 0x3f)] |
sbox4->output[sbox4->input_lookup[in] ^ ((key >> 18) & 0x3f)];
}
// srckey is the 64-bit master key (2x32 bits)
// dstkey will contain the 96-bit key for the 1st FN (4x24 bits)
static void expand_1st_key(ut32 *dstkey, const ut32 *srckey) {
static const int bits[96] = {
33, 58, 49, 36, 0, 31,
22, 30, 3, 16, 5, 53,
10, 41, 23, 19, 27, 39,
43, 6, 34, 12, 61, 21,
48, 13, 32, 35, 6, 42,
43, 14, 21, 41, 52, 25,
18, 47, 46, 37, 57, 53,
20, 8, 55, 54, 59, 60,
27, 33, 35, 18, 8, 15,
63, 1, 50, 44, 16, 46,
5, 4, 45, 51, 38, 25,
13, 11, 62, 29, 48, 2,
59, 61, 62, 56, 51, 57,
54, 9, 24, 63, 22, 7,
26, 42, 45, 40, 23, 14,
2, 31, 52, 28, 44, 17,
};
int i;
dstkey[0] = 0;
dstkey[1] = 0;
dstkey[2] = 0;
dstkey[3] = 0;
for (i = 0; i < 96; ++i)
dstkey[i / 24] |= BIT(srckey[bits[i] / 32], bits[i] % 32) << (i % 24);
}
// srckey is the 64-bit master key (2x32 bits) XORed with the subkey
// dstkey will contain the 96-bit key for the 2nd FN (4x24 bits)
static void expand_2nd_key(ut32 *dstkey, const ut32 *srckey) {
static const int bits[96] = {
34, 9, 32, 24, 44, 54,
38, 61, 47, 13, 28, 7,
29, 58, 18, 1, 20, 60,
15, 6, 11, 43, 39, 19,
63, 23, 16, 62, 54, 40,
31, 3, 56, 61, 17, 25,
47, 38, 55, 57, 5, 4,
15, 42, 22, 7, 2, 19,
46, 37, 29, 39, 12, 30,
49, 57, 31, 41, 26, 27,
24, 36, 11, 63, 33, 16,
56, 62, 48, 60, 59, 32,
12, 30, 53, 48, 10, 0,
50, 35, 3, 59, 14, 49,
51, 45, 44, 2, 21, 33,
55, 52, 23, 28, 8, 26,
};
int i;
dstkey[0] = 0;
dstkey[1] = 0;
dstkey[2] = 0;
dstkey[3] = 0;
for (i = 0; i < 96; ++i) {
dstkey[i / 24] |= BIT(srckey[bits[i] / 32], bits[i] % 32) << (i % 24);
}
}
// seed is the 16-bit seed generated by the first FN
// subkey will contain the 64-bit key to be XORed with the master key
// for the 2nd FN (2x32 bits)
static void expand_subkey(ut32* subkey, ut16 seed) {
// Note that each row of the table is a permutation of the seed bits.
static const int bits[64] = {
5, 10, 14, 9, 4, 0, 15, 6, 1, 8, 3, 2, 12, 7, 13, 11,
5, 12, 7, 2, 13, 11, 9, 14, 4, 1, 6, 10, 8, 0, 15, 3,
4, 10, 2, 0, 6, 9, 12, 1, 11, 7, 15, 8, 13, 5, 14, 3,
14, 11, 12, 7, 4, 5, 2, 10, 1, 15, 0, 9, 8, 6, 13, 3,
};
int i;
subkey[0] = 0;
subkey[1] = 0;
for (i = 0; i < 64; ++i) {
subkey[i / 32] |= BIT(seed, bits[i]) << (i % 32);
}
}
static inline ut16 feistel(ut16 val, const int *bitsA, const int *bitsB,
const struct optimised_sbox* boxes1, const struct optimised_sbox* boxes2,
const struct optimised_sbox* boxes3, const struct optimised_sbox* boxes4,
ut32 key1, ut32 key2, ut32 key3, ut32 key4)
{
ut8 l = BITSWAP8(val, bitsB[7],bitsB[6],bitsB[5],bitsB[4],bitsB[3],bitsB[2],bitsB[1],bitsB[0]);
ut8 r = BITSWAP8(val, bitsA[7],bitsA[6],bitsA[5],bitsA[4],bitsA[3],bitsA[2],bitsA[1],bitsA[0]);
l ^= fn(r, boxes1, key1);
r ^= fn(l, boxes2, key2);
l ^= fn(r, boxes3, key3);
r ^= fn(l, boxes4, key4);
return
(BIT(l, 0) << bitsA[0]) |
(BIT(l, 1) << bitsA[1]) |
(BIT(l, 2) << bitsA[2]) |
(BIT(l, 3) << bitsA[3]) |
(BIT(l, 4) << bitsA[4]) |
(BIT(l, 5) << bitsA[5]) |
(BIT(l, 6) << bitsA[6]) |
(BIT(l, 7) << bitsA[7]) |
(BIT(r, 0) << bitsB[0]) |
(BIT(r, 1) << bitsB[1]) |
(BIT(r, 2) << bitsB[2]) |
(BIT(r, 3) << bitsB[3]) |
(BIT(r, 4) << bitsB[4]) |
(BIT(r, 5) << bitsB[5]) |
(BIT(r, 6) << bitsB[6]) |
(BIT(r, 7) << bitsB[7]);
}
static int extract_inputs(ut32 val, const int *inputs) {
int i, res = 0;
for (i = 0; i < 6; ++i) {
if (inputs[i] != -1) {
res |= BIT (val, inputs[i]) << i;
}
}
return res;
}
static void optimise_sboxes(struct optimised_sbox* out, const struct sbox* in) {
int i, box;
for (box = 0; box < 4; ++box) {
// precalculate the input lookup
for (i = 0; i < 256; ++i) {
out[box].input_lookup[i] = extract_inputs(i, in[box].inputs);
}
// precalculate the output masks
for (i = 0; i < 64; ++i) {
int o = in[box].table[i];
out[box].output[i] = 0;
if (o & 1) {
out[box].output[i] |= 1 << in[box].outputs[0];
}
if (o & 2) {
out[box].output[i] |= 1 << in[box].outputs[1];
}
}
}
}
static void cps2_decrypt(const ut16 *rom, ut16 *dec, int length, const ut32 *master_key, ut32 upper_limit) {
int i;
ut32 key1[4];
struct optimised_sbox sboxes1[4*4];
struct optimised_sbox sboxes2[4*4];
optimise_sboxes(&sboxes1[0*4], fn1_r1_boxes);
optimise_sboxes(&sboxes1[1*4], fn1_r2_boxes);
optimise_sboxes(&sboxes1[2*4], fn1_r3_boxes);
optimise_sboxes(&sboxes1[3*4], fn1_r4_boxes);
optimise_sboxes(&sboxes2[0*4], fn2_r1_boxes);
optimise_sboxes(&sboxes2[1*4], fn2_r2_boxes);
optimise_sboxes(&sboxes2[2*4], fn2_r3_boxes);
optimise_sboxes(&sboxes2[3*4], fn2_r4_boxes);
// expand master key to 1st FN 96-bit key
expand_1st_key(key1, master_key);
// add extra bits for s-boxes with less than 6 inputs
key1[0] ^= BIT(key1[0], 1) << 4;
key1[0] ^= BIT(key1[0], 2) << 5;
key1[0] ^= BIT(key1[0], 8) << 11;
key1[1] ^= BIT(key1[1], 0) << 5;
key1[1] ^= BIT(key1[1], 8) << 11;
key1[2] ^= BIT(key1[2], 1) << 5;
key1[2] ^= BIT(key1[2], 8) << 11;
for (i = 0; i < 0x10000; ++i) {
int a;
ut16 seed;
ut32 subkey[2];
ut32 key2[4];
if ((i & 0xff) == 0) {
eprintf ("Decrypting %d%%\r", i*100/0x10000);
}
// pass the address through FN1
seed = feistel(i, fn1_groupA, fn1_groupB,
&sboxes1[0*4], &sboxes1[1*4], &sboxes1[2*4], &sboxes1[3*4],
key1[0], key1[1], key1[2], key1[3]);
// expand the result to 64-bit
expand_subkey (subkey, seed);
// XOR with the master key
subkey[0] ^= master_key[0];
subkey[1] ^= master_key[1];
// expand key to 2nd FN 96-bit key
expand_2nd_key (key2, subkey);
// add extra bits for s-boxes with less than 6 inputs
key2[0] ^= BIT(key2[0], 0) << 5;
key2[0] ^= BIT(key2[0], 6) << 11;
key2[1] ^= BIT(key2[1], 0) << 5;
key2[1] ^= BIT(key2[1], 1) << 4;
key2[2] ^= BIT(key2[2], 2) << 5;
key2[2] ^= BIT(key2[2], 3) << 4;
key2[2] ^= BIT(key2[2], 7) << 11;
key2[3] ^= BIT(key2[3], 1) << 5;
// decrypt the opcodes
for (a = i; a < length/2 && a < upper_limit/2; a += 0x10000) {
dec[a] = feistel(rom[a], fn2_groupA, fn2_groupB,
&sboxes2[0*4], &sboxes2[1*4], &sboxes2[2*4], &sboxes2[3*4],
key2[0], key2[1], key2[2], key2[3]);
}
// copy the unencrypted part
while (a < length/2) {
dec[a] = rom[a];
a += 0x10000;
}
}
}
#if 0
main(cps_state,cps2crypt) {
ut32 key[2];
ut32 lower;
ut32 upper;
std::string skey1 = parameter("cryptkey1");;
key[0] = strtoll(skey1.c_str(), nullptr, 16);
std::string skey2 = parameter("cryptkey2");
key[1] = strtoll(skey2.c_str(), nullptr, 16);
std::string slower = parameter("cryptlower");
lower = strtoll(slower.c_str(), nullptr, 16); // unused
std::string supper = parameter("cryptupper");
upper = strtoll(supper.c_str(), nullptr, 16);
// we have a proper key so use it to decrypt
if (lower != 0xff0000) {// don't run the decrypt on 'dead key' games for now
cps2_decrypt( (ut16 *)memregion("maincpu")->base(), m_decrypted_opcodes, memregion("maincpu")->bytes(), key, lower,upper);
}
}
#endif
static ut32 cps2key[2] = {0};
static int set_key(RCrypto *cry, const ut8 *key, int keylen, int mode, int direction) {
if (keylen == 8) {
memcpy (&cps2key, key, keylen);
}
return 0;
}
static int get_key_size(RCrypto *cry) {
/* 64bit key */
return 8;
}
static bool cps2_use(const char *algo) {
return !strcmp (algo, "cps2");
}
static int update(RCrypto *cry, const ut8 *buf, int len) {
ut8 *output = calloc (1, len);
/* TODO : control decryption errors */
cps2_decrypt ((const ut16 *)buf, (ut16*)output, len, cps2key, UPPER_LIMIT);
r_crypto_append (cry, output, len);
free (output);
return true;
}
RCryptoPlugin r_crypto_plugin_cps2 = {
.name = "cps2",
.set_key = set_key,
.get_key_size = get_key_size,
.use = cps2_use,
.update = update
};
#ifndef CORELIB
struct r_lib_struct_t radare_plugin = {
.type = R_LIB_TYPE_CRYPTO,
.data = &r_crypto_plugin_rol,
.version = R2_VERSION
};
#endif
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