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Diffstat (limited to 'src/mame/machine/315-5881_crypt.h')
-rw-r--r--src/mame/machine/315-5881_crypt.h87
1 files changed, 87 insertions, 0 deletions
diff --git a/src/mame/machine/315-5881_crypt.h b/src/mame/machine/315-5881_crypt.h
new file mode 100644
index 00000000000..fcea2a21a2d
--- /dev/null
+++ b/src/mame/machine/315-5881_crypt.h
@@ -0,0 +1,87 @@
+
+#pragma once
+
+#ifndef __SEGA315_5881_CRYPT__
+#define __SEGA315_5881_CRYPT__
+
+typedef device_delegate<UINT16 (UINT32)> sega_m2_read_delegate;
+
+extern const device_type SEGA315_5881_CRYPT;
+
+#define MCFG_SET_READ_CALLBACK( _class, _method) \
+ sega_315_5881_crypt_device::set_read_cb(*device, sega_m2_read_delegate(&_class::_method, #_class "::" #_method, NULL, (_class *)0));
+
+
+class sega_315_5881_crypt_device : public device_t
+{
+public:
+ // construction/destruction
+ sega_315_5881_crypt_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+
+ void do_decrypt(UINT8 *&base);
+ void set_addr_low(UINT16 data);
+ void set_addr_high(UINT16 data);
+ void set_subkey(UINT16 data);
+ void set_key(UINT32 data);
+
+ sega_m2_read_delegate m_read;
+
+ static void set_read_cb(device_t &device,sega_m2_read_delegate readcb)
+ {
+ sega_315_5881_crypt_device &dev = downcast<sega_315_5881_crypt_device &>(device);
+ dev.m_read = readcb;
+ }
+
+protected:
+ virtual void device_start();
+ virtual void device_reset();
+
+private:
+
+ enum {
+ BUFFER_SIZE = 32768, LINE_SIZE = 512,
+ FLAG_COMPRESSED = 0x10000, FLAG_LINE_SIZE_512 = 0x20000
+ };
+
+ UINT32 key;
+
+ UINT8 *buffer, *line_buffer, *line_buffer_prev;
+ UINT32 prot_cur_address;
+ UINT16 subkey, dec_hist;
+ UINT32 dec_header;
+
+ bool enc_ready;
+
+ int buffer_pos, line_buffer_pos, line_buffer_size, buffer_bit;
+
+ struct sbox {
+ UINT8 table[64];
+ int inputs[6]; // positions of the inputs bits, -1 means no input except from key
+ int outputs[2]; // positions of the output bits
+ };
+
+ static const sbox fn1_sboxes[4][4];
+ static const sbox fn2_sboxes[4][4];
+
+ static const int fn1_game_key_scheduling[38][2];
+ static const int fn2_game_key_scheduling[34][2];
+ static const int fn1_sequence_key_scheduling[20][2];
+ static const int fn2_sequence_key_scheduling[16];
+ static const int fn2_middle_result_scheduling[16];
+
+ static const UINT8 trees[9][2][32];
+
+ int feistel_function(int input, const struct sbox *sboxes, UINT32 subkeys);
+ UINT16 block_decrypt(UINT32 game_key, UINT16 sequence_key, UINT16 counter, UINT16 data);
+
+ UINT16 get_decrypted_16();
+ int get_compressed_bit();
+
+ void enc_start();
+ void enc_fill();
+ void line_fill();
+
+};
+
+#endif