Help porting some code from C++

[Zorm]

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static unsigned int p_table[CRYPT_GAMEKEY_COUNT][18];
static unsigned int s_table[CRYPT_GAMEKEY_COUNT][1024];

#define ROUND(LL, R, S, P) \
   LL = \
       (LL) \
       ^ (P) \
       ^ ( \
           ( \
               S[(R) >> 24] \
               + S[0x0100 + (((R) >> 16) & 0xff)] \
           ) ^ S[0x0200 + (((R) >> 8) & 0xff)] \
       ) + S[0x0300 + ((R) & 0xff)]

bool m_tables_ready = false;

void init_tables()
{
   for(int key_index = 0; key_index < CRYPT_GAMEKEY_COUNT; key_index++)
   {
       int i;
       memcpy(p_table[key_index], p_box, sizeof(p_box));
       memcpy(s_table[key_index], s_box, sizeof(s_box));

       unsigned char * pkey = g_key_table[key_index];
       unsigned char * pkey_end = g_key_table[key_index + 1];

       for(i = 0; i < 18; i++)
       {
           unsigned int mask = *pkey++;
           if(pkey >= pkey_end)
               pkey = g_key_table[key_index];

           mask = ( mask << 8) | *pkey++;
           if(pkey >= pkey_end)
               pkey = g_key_table[key_index];

           mask = ( mask << 8) | *pkey++;
           if(pkey >= pkey_end)
               pkey = g_key_table[key_index];

           mask = ( mask << 8) | *pkey++;
           if(pkey >= pkey_end)
               pkey = g_key_table[key_index];

           p_table[key_index][i] ^= mask;
       }

       unsigned int value[2] = { 0, 0 };

       for(i = 0; i < 18; i += 2)
       {
           raw_encrypt(value, key_index);
           p_table[key_index][i] = value[0];
           p_table[key_index][i+1] = value[1];
       }

       for(i = 0; i < 1024; i += 2)
       {
           raw_encrypt(value, key_index);
           s_table[key_index][i] = value[0];
           s_table[key_index][i+1] = value[1];
       }
   }

   m_tables_ready = true;
}

void raw_encrypt(unsigned int * values, int table)
{
   unsigned int left = values[0];
   unsigned int right = values[1];

   left ^= p_table[table][0];

   ROUND(right, left, s_table[table], p_table[table][1]);
   ROUND(left, right, s_table[table], p_table[table][2]);
   ROUND(right, left, s_table[table], p_table[table][3]);
   ROUND(left, right, s_table[table], p_table[table][4]);
   ROUND(right, left, s_table[table], p_table[table][5]);
   ROUND(left, right, s_table[table], p_table[table][6]);
   ROUND(right, left, s_table[table], p_table[table][7]);
   ROUND(left, right, s_table[table], p_table[table][8]);
   ROUND(right, left, s_table[table], p_table[table][9]);
   ROUND(left, right, s_table[table], p_table[table][10]);
   ROUND(right, left, s_table[table], p_table[table][11]);
   ROUND(left, right, s_table[table], p_table[table][12]);
   ROUND(right, left, s_table[table], p_table[table][13]);
   ROUND(left, right, s_table[table], p_table[table][14]);
   ROUND(right, left, s_table[table], p_table[table][15]);
   ROUND(left, right, s_table[table], p_table[table][16]);

   right ^= p_table[table][17];

   values[1] = left;
   values[0] = right;
}
void encrypt(unsigned char * in, unsigned char * out, int len)
{
   while(m_stream_pos + len > CRYPT_GAMETABLE_TRIGGER)
   {
       int len_remaining = CRYPT_GAMETABLE_TRIGGER - m_stream_pos;

       encrypt(in, out, len_remaining);

       m_table_index = (m_table_index + CRYPT_GAMETABLE_STEP) %
           CRYPT_GAMETABLE_MODULO;
       memcpy(m_seed, g_seed_table[1][m_table_index][0],
           CRYPT_GAMESEED_LENGTH);
       m_stream_pos = 0;
       m_block_pos = 0;

       in += len_remaining;
       out += len_remaining;
       len -= len_remaining;
   }

   for(int i = 0; i < len; i++)
   {
       if(m_block_pos == 0)
       {
           unsigned int values[2];

           unsigned char * seed = m_seed;
           N2L(seed, values[0]);
           N2L(seed, values[1]);

           raw_encrypt(values, m_table_index);

           seed = m_seed;
           L2N(values[0], seed);
           L2N(values[1], seed);
       }
       unsigned char c = (*in++) ^ m_seed[m_block_pos];
       *out++ = c;

       m_seed[m_block_pos] = c;
       m_block_pos = (m_block_pos + 1) % 8;
   }

   m_stream_pos += len;
}

So uh anyone care to port/help port this to java?

[iago]

What exactly are you stuck on?  I can help with bits and pieces, but I'm not going to do all that code

[Zorm]

Unsure of how to handle the memcpys and then *pkey++ in init_tables

[Adron]

Unsure of how to handle the memcpys and then *pkey++ in init_tables

A memcpy can be replaced with a loop iterating over and copying the data.

The *pkey++ should probably be replaced with indexing by an integer variable and increasing that.

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 char *pkey = "Testing testing";
 // code 1:
 int i = 0;
 while(pkey[i])
     pkey[i++] += 1;
 // equivalent code 2 (except pkey is moved):
 while(*pkey)
     *pkey++ += 1;


[iago]

Unsure of how to handle the memcpys and then *pkey++ in init_tables

A memcpy can be replaced with a loop iterating over and copying the data.

Depending on what's being memcpy'd, you might be able to use clone().

[Kp]

Also consider System.arraycopy()