/*
* MARS
* (C) 1999-2009 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/

#include <botan/mars.h>
#include <botan/loadstor.h>
#include <botan/rotate.h>

namespace Botan {

namespace {

/**
* The MARS sbox
*/
const u32bit SBOX[512] = {
   0x09D0C479, 0x28C8FFE0, 0x84AA6C39, 0x9DAD7287, 0x7DFF9BE3, 0xD4268361,
   0xC96DA1D4, 0x7974CC93, 0x85D0582E, 0x2A4B5705, 0x1CA16A62, 0xC3BD279D,
   0x0F1F25E5, 0x5160372F, 0xC695C1FB, 0x4D7FF1E4, 0xAE5F6BF4, 0x0D72EE46,
   0xFF23DE8A, 0xB1CF8E83, 0xF14902E2, 0x3E981E42, 0x8BF53EB6, 0x7F4BF8AC,
   0x83631F83, 0x25970205, 0x76AFE784, 0x3A7931D4, 0x4F846450, 0x5C64C3F6,
   0x210A5F18, 0xC6986A26, 0x28F4E826, 0x3A60A81C, 0xD340A664, 0x7EA820C4,
   0x526687C5, 0x7EDDD12B, 0x32A11D1D, 0x9C9EF086, 0x80F6E831, 0xAB6F04AD,
   0x56FB9B53, 0x8B2E095C, 0xB68556AE, 0xD2250B0D, 0x294A7721, 0xE21FB253,
   0xAE136749, 0xE82AAE86, 0x93365104, 0x99404A66, 0x78A784DC, 0xB69BA84B,
   0x04046793, 0x23DB5C1E, 0x46CAE1D6, 0x2FE28134, 0x5A223942, 0x1863CD5B,
   0xC190C6E3, 0x07DFB846, 0x6EB88816, 0x2D0DCC4A, 0xA4CCAE59, 0x3798670D,
   0xCBFA9493, 0x4F481D45, 0xEAFC8CA8, 0xDB1129D6, 0xB0449E20, 0x0F5407FB,
   0x6167D9A8, 0xD1F45763, 0x4DAA96C3, 0x3BEC5958, 0xABABA014, 0xB6CCD201,
   0x38D6279F, 0x02682215, 0x8F376CD5, 0x092C237E, 0xBFC56593, 0x32889D2C,
   0x854B3E95, 0x05BB9B43, 0x7DCD5DCD, 0xA02E926C, 0xFAE527E5, 0x36A1C330,
   0x3412E1AE, 0xF257F462, 0x3C4F1D71, 0x30A2E809, 0x68E5F551, 0x9C61BA44,
   0x5DED0AB8, 0x75CE09C8, 0x9654F93E, 0x698C0CCA, 0x243CB3E4, 0x2B062B97,
   0x0F3B8D9E, 0x00E050DF, 0xFC5D6166, 0xE35F9288, 0xC079550D, 0x0591AEE8,
   0x8E531E74, 0x75FE3578, 0x2F6D829A, 0xF60B21AE, 0x95E8EB8D, 0x6699486B,
   0x901D7D9B, 0xFD6D6E31, 0x1090ACEF, 0xE0670DD8, 0xDAB2E692, 0xCD6D4365,
   0xE5393514, 0x3AF345F0, 0x6241FC4D, 0x460DA3A3, 0x7BCF3729, 0x8BF1D1E0,
   0x14AAC070, 0x1587ED55, 0x3AFD7D3E, 0xD2F29E01, 0x29A9D1F6, 0xEFB10C53,
   0xCF3B870F, 0xB414935C, 0x664465ED, 0x024ACAC7, 0x59A744C1, 0x1D2936A7,
   0xDC580AA6, 0xCF574CA8, 0x040A7A10, 0x6CD81807, 0x8A98BE4C, 0xACCEA063,
   0xC33E92B5, 0xD1E0E03D, 0xB322517E, 0x2092BD13, 0x386B2C4A, 0x52E8DD58,
   0x58656DFB, 0x50820371, 0x41811896, 0xE337EF7E, 0xD39FB119, 0xC97F0DF6,
   0x68FEA01B, 0xA150A6E5, 0x55258962, 0xEB6FF41B, 0xD7C9CD7A, 0xA619CD9E,
   0xBCF09576, 0x2672C073, 0xF003FB3C, 0x4AB7A50B, 0x1484126A, 0x487BA9B1,
   0xA64FC9C6, 0xF6957D49, 0x38B06A75, 0xDD805FCD, 0x63D094CF, 0xF51C999E,
   0x1AA4D343, 0xB8495294, 0xCE9F8E99, 0xBFFCD770, 0xC7C275CC, 0x378453A7,
   0x7B21BE33, 0x397F41BD, 0x4E94D131, 0x92CC1F98, 0x5915EA51, 0x99F861B7,
   0xC9980A88, 0x1D74FD5F, 0xB0A495F8, 0x614DEED0, 0xB5778EEA, 0x5941792D,
   0xFA90C1F8, 0x33F824B4, 0xC4965372, 0x3FF6D550, 0x4CA5FEC0, 0x8630E964,
   0x5B3FBBD6, 0x7DA26A48, 0xB203231A, 0x04297514, 0x2D639306, 0x2EB13149,
   0x16A45272, 0x532459A0, 0x8E5F4872, 0xF966C7D9, 0x07128DC0, 0x0D44DB62,
   0xAFC8D52D, 0x06316131, 0xD838E7CE, 0x1BC41D00, 0x3A2E8C0F, 0xEA83837E,
   0xB984737D, 0x13BA4891, 0xC4F8B949, 0xA6D6ACB3, 0xA215CDCE, 0x8359838B,
   0x6BD1AA31, 0xF579DD52, 0x21B93F93, 0xF5176781, 0x187DFDDE, 0xE94AEB76,
   0x2B38FD54, 0x431DE1DA, 0xAB394825, 0x9AD3048F, 0xDFEA32AA, 0x659473E3,
   0x623F7863, 0xF3346C59, 0xAB3AB685, 0x3346A90B, 0x6B56443E, 0xC6DE01F8,
   0x8D421FC0, 0x9B0ED10C, 0x88F1A1E9, 0x54C1F029, 0x7DEAD57B, 0x8D7BA426,
   0x4CF5178A, 0x551A7CCA, 0x1A9A5F08, 0xFCD651B9, 0x25605182, 0xE11FC6C3,
   0xB6FD9676, 0x337B3027, 0xB7C8EB14, 0x9E5FD030, 0x6B57E354, 0xAD913CF7,
   0x7E16688D, 0x58872A69, 0x2C2FC7DF, 0xE389CCC6, 0x30738DF1, 0x0824A734,
   0xE1797A8B, 0xA4A8D57B, 0x5B5D193B, 0xC8A8309B, 0x73F9A978, 0x73398D32,
   0x0F59573E, 0xE9DF2B03, 0xE8A5B6C8, 0x848D0704, 0x98DF93C2, 0x720A1DC3,
   0x684F259A, 0x943BA848, 0xA6370152, 0x863B5EA3, 0xD17B978B, 0x6D9B58EF,
   0x0A700DD4, 0xA73D36BF, 0x8E6A0829, 0x8695BC14, 0xE35B3447, 0x933AC568,
   0x8894B022, 0x2F511C27, 0xDDFBCC3C, 0x006662B6, 0x117C83FE, 0x4E12B414,
   0xC2BCA766, 0x3A2FEC10, 0xF4562420, 0x55792E2A, 0x46F5D857, 0xCEDA25CE,
   0xC3601D3B, 0x6C00AB46, 0xEFAC9C28, 0xB3C35047, 0x611DFEE3, 0x257C3207,
   0xFDD58482, 0x3B14D84F, 0x23BECB64, 0xA075F3A3, 0x088F8EAD, 0x07ADF158,
   0x7796943C, 0xFACABF3D, 0xC09730CD, 0xF7679969, 0xDA44E9ED, 0x2C854C12,
   0x35935FA3, 0x2F057D9F, 0x690624F8, 0x1CB0BAFD, 0x7B0DBDC6, 0x810F23BB,
   0xFA929A1A, 0x6D969A17, 0x6742979B, 0x74AC7D05, 0x010E65C4, 0x86A3D963,
   0xF907B5A0, 0xD0042BD3, 0x158D7D03, 0x287A8255, 0xBBA8366F, 0x096EDC33,
   0x21916A7B, 0x77B56B86, 0x951622F9, 0xA6C5E650, 0x8CEA17D1, 0xCD8C62BC,
   0xA3D63433, 0x358A68FD, 0x0F9B9D3C, 0xD6AA295B, 0xFE33384A, 0xC000738E,
   0xCD67EB2F, 0xE2EB6DC2, 0x97338B02, 0x06C9F246, 0x419CF1AD, 0x2B83C045,
   0x3723F18A, 0xCB5B3089, 0x160BEAD7, 0x5D494656, 0x35F8A74B, 0x1E4E6C9E,
   0x000399BD, 0x67466880, 0xB4174831, 0xACF423B2, 0xCA815AB3, 0x5A6395E7,
   0x302A67C5, 0x8BDB446B, 0x108F8FA4, 0x10223EDA, 0x92B8B48B, 0x7F38D0EE,
   0xAB2701D4, 0x0262D415, 0xAF224A30, 0xB3D88ABA, 0xF8B2C3AF, 0xDAF7EF70,
   0xCC97D3B7, 0xE9614B6C, 0x2BAEBFF4, 0x70F687CF, 0x386C9156, 0xCE092EE5,
   0x01E87DA6, 0x6CE91E6A, 0xBB7BCC84, 0xC7922C20, 0x9D3B71FD, 0x060E41C6,
   0xD7590F15, 0x4E03BB47, 0x183C198E, 0x63EEB240, 0x2DDBF49A, 0x6D5CBA54,
   0x923750AF, 0xF9E14236, 0x7838162B, 0x59726C72, 0x81B66760, 0xBB2926C1,
   0x48A0CE0D, 0xA6C0496D, 0xAD43507B, 0x718D496A, 0x9DF057AF, 0x44B1BDE6,
   0x054356DC, 0xDE7CED35, 0xD51A138B, 0x62088CC9, 0x35830311, 0xC96EFCA2,
   0x686F86EC, 0x8E77CB68, 0x63E1D6B8, 0xC80F9778, 0x79C491FD, 0x1B4C67F2,
   0x72698D7D, 0x5E368C31, 0xF7D95E2E, 0xA1D3493F, 0xDCD9433E, 0x896F1552,
   0x4BC4CA7A, 0xA6D1BAF4, 0xA5A96DCC, 0x0BEF8B46, 0xA169FDA7, 0x74DF40B7,
   0x4E208804, 0x9A756607, 0x038E87C8, 0x20211E44, 0x8B7AD4BF, 0xC6403F35,
   0x1848E36D, 0x80BDB038, 0x1E62891C, 0x643D2107, 0xBF04D6F8, 0x21092C8C,
   0xF644F389, 0x0778404E, 0x7B78ADB8, 0xA2C52D53, 0x42157ABE, 0xA2253E2E,
   0x7BF3F4AE, 0x80F594F9, 0x953194E7, 0x77EB92ED, 0xB3816930, 0xDA8D9336,
   0xBF447469, 0xF26D9483, 0xEE6FAED5, 0x71371235, 0xDE425F73, 0xB4E59F43,
   0x7DBE2D4E, 0x2D37B185, 0x49DC9A63, 0x98C39D98, 0x1301C9A2, 0x389B1BBF,
   0x0C18588D, 0xA421C1BA, 0x7AA3865C, 0x71E08558, 0x3C5CFCAA, 0x7D239CA4,
   0x0297D9DD, 0xD7DC2830, 0x4B37802B, 0x7428AB54, 0xAEEE0347, 0x4B3FBB85,
   0x692F2F08, 0x134E578E, 0x36D9E0BF, 0xAE8B5FCF, 0xEDB93ECF, 0x2B27248E,
   0x170EB1EF, 0x7DC57FD6, 0x1E760F16, 0xB1136601, 0x864E1B9B, 0xD7EA7319,
   0x3AB871BD, 0xCFA4D76F, 0xE31BD782, 0x0DBEB469, 0xABB96061, 0x5370F85D,
   0xFFB07E37, 0xDA30D0FB, 0xEBC977B6, 0x0B98B40F, 0x3A4D0FE6, 0xDF4FC26B,
   0x159CF22A, 0xC298D6E2, 0x2B78EF6A, 0x61A94AC0, 0xAB561187, 0x14EEA0F0,
   0xDF0D4164, 0x19AF70EE };

/*
* MARS Encryption Round
*/
inline void encrypt_round(u32bit& A, u32bit& B, u32bit& C, u32bit& D,
                          u32bit EK1, u32bit EK2)
   {
   u32bit X = A + EK1;
   A  = rotate_left(A, 13);
   u32bit Y = A * EK2;
   u32bit Z = SBOX[X % 512];

   Y  = rotate_left(Y, 5);
   Z ^= Y;
   C += rotate_left(X, Y % 32);
   Y  = rotate_left(Y, 5);
   Z ^= Y;
   D ^= Y;
   B += rotate_left(Z, Y % 32);
   }

/*
* MARS Decryption Round
*/
inline void decrypt_round(u32bit& A, u32bit& B, u32bit& C, u32bit& D,
                          u32bit EK1, u32bit EK2)
   {
   u32bit Y = A * EK1;
   A = rotate_right(A, 13);
   u32bit X = A + EK2;
   u32bit Z = SBOX[X % 512];

   Y  = rotate_left(Y, 5);
   Z ^= Y;
   C -= rotate_left(X, Y % 32);
   Y  = rotate_left(Y, 5);
   Z ^= Y;
   D ^= Y;
   B -= rotate_left(Z, Y % 32);
   }

/*
* MARS Forward Mixing Operation
*/
void forward_mix(u32bit& A, u32bit& B, u32bit& C, u32bit& D)
   {
   for(u32bit j = 0; j != 2; ++j)
      {
      B ^= SBOX[get_byte(3, A)]; B += SBOX[get_byte(2, A) + 256];
      C += SBOX[get_byte(1, A)]; D ^= SBOX[get_byte(0, A) + 256];
      A = rotate_right(A, 24) + D;

      C ^= SBOX[get_byte(3, B)]; C += SBOX[get_byte(2, B) + 256];
      D += SBOX[get_byte(1, B)]; A ^= SBOX[get_byte(0, B) + 256];
      B = rotate_right(B, 24) + C;

      D ^= SBOX[get_byte(3, C)]; D += SBOX[get_byte(2, C) + 256];
      A += SBOX[get_byte(1, C)]; B ^= SBOX[get_byte(0, C) + 256];
      C = rotate_right(C, 24);

      A ^= SBOX[get_byte(3, D)]; A += SBOX[get_byte(2, D) + 256];
      B += SBOX[get_byte(1, D)]; C ^= SBOX[get_byte(0, D) + 256];
      D = rotate_right(D, 24);
      }
   }

/*
* MARS Reverse Mixing Operation
*/
void reverse_mix(u32bit& A, u32bit& B, u32bit& C, u32bit& D)
   {
   for(u32bit j = 0; j != 2; ++j)
      {
      B ^= SBOX[get_byte(3, A) + 256]; C -= SBOX[get_byte(0, A)];
      D -= SBOX[get_byte(1, A) + 256]; D ^= SBOX[get_byte(2, A)];
      A = rotate_left(A, 24);

      C ^= SBOX[get_byte(3, B) + 256]; D -= SBOX[get_byte(0, B)];
      A -= SBOX[get_byte(1, B) + 256]; A ^= SBOX[get_byte(2, B)];
      C -= (B = rotate_left(B, 24));

      D ^= SBOX[get_byte(3, C) + 256]; A -= SBOX[get_byte(0, C)];
      B -= SBOX[get_byte(1, C) + 256]; B ^= SBOX[get_byte(2, C)];
      C = rotate_left(C, 24);
      D -= A;

      A ^= SBOX[get_byte(3, D) + 256]; B -= SBOX[get_byte(0, D)];
      C -= SBOX[get_byte(1, D) + 256]; C ^= SBOX[get_byte(2, D)];
      D = rotate_left(D, 24);
      }
   }

/*
* Generate a mask for runs of bits
*/
u32bit gen_mask(u32bit input)
   {
   u32bit mask = 0;

   for(u32bit j = 2; j != 31; ++j)
      {
      u32bit region = (input >> (j-1)) & 0x07;

      if(region == 0x00 || region == 0x07)
         {
         u32bit low = (j < 9) ? 0 : (j - 9);
         u32bit high = (j < 23) ? j : 23;

         for(u32bit k = low; k != high; ++k)
            {
            u32bit value = (input >> k) & 0x3FF;

            if(value == 0 || value == 0x3FF)
               {
               mask |= 1 << j;
               break;
               }
            }
         }
      }

   return mask;
   }

}

/*
* MARS Encryption
*/
void MARS::encrypt_n(const byte in[], byte out[], u32bit blocks) const
   {
   for(u32bit i = 0; i != blocks; ++i)
      {
      u32bit A = load_le<u32bit>(in, 0) + EK[0];
      u32bit B = load_le<u32bit>(in, 1) + EK[1];
      u32bit C = load_le<u32bit>(in, 2) + EK[2];
      u32bit D = load_le<u32bit>(in, 3) + EK[3];

      forward_mix(A, B, C, D);

      encrypt_round(A, B, C, D, EK[ 4], EK[ 5]);
      encrypt_round(B, C, D, A, EK[ 6], EK[ 7]);
      encrypt_round(C, D, A, B, EK[ 8], EK[ 9]);
      encrypt_round(D, A, B, C, EK[10], EK[11]);
      encrypt_round(A, B, C, D, EK[12], EK[13]);
      encrypt_round(B, C, D, A, EK[14], EK[15]);
      encrypt_round(C, D, A, B, EK[16], EK[17]);
      encrypt_round(D, A, B, C, EK[18], EK[19]);

      encrypt_round(A, D, C, B, EK[20], EK[21]);
      encrypt_round(B, A, D, C, EK[22], EK[23]);
      encrypt_round(C, B, A, D, EK[24], EK[25]);
      encrypt_round(D, C, B, A, EK[26], EK[27]);
      encrypt_round(A, D, C, B, EK[28], EK[29]);
      encrypt_round(B, A, D, C, EK[30], EK[31]);
      encrypt_round(C, B, A, D, EK[32], EK[33]);
      encrypt_round(D, C, B, A, EK[34], EK[35]);

      reverse_mix(A, B, C, D);

      A -= EK[36]; B -= EK[37]; C -= EK[38]; D -= EK[39];

      store_le(out, A, B, C, D);

      in += BLOCK_SIZE;
      out += BLOCK_SIZE;
      }
   }

/*
* MARS Decryption
*/
void MARS::decrypt_n(const byte in[], byte out[], u32bit blocks) const
   {
   for(u32bit i = 0; i != blocks; ++i)
      {
      u32bit A = load_le<u32bit>(in, 3) + EK[39];
      u32bit B = load_le<u32bit>(in, 2) + EK[38];
      u32bit C = load_le<u32bit>(in, 1) + EK[37];
      u32bit D = load_le<u32bit>(in, 0) + EK[36];

      forward_mix(A, B, C, D);

      decrypt_round(A, B, C, D, EK[35], EK[34]);
      decrypt_round(B, C, D, A, EK[33], EK[32]);
      decrypt_round(C, D, A, B, EK[31], EK[30]);
      decrypt_round(D, A, B, C, EK[29], EK[28]);
      decrypt_round(A, B, C, D, EK[27], EK[26]);
      decrypt_round(B, C, D, A, EK[25], EK[24]);
      decrypt_round(C, D, A, B, EK[23], EK[22]);
      decrypt_round(D, A, B, C, EK[21], EK[20]);

      decrypt_round(A, D, C, B, EK[19], EK[18]);
      decrypt_round(B, A, D, C, EK[17], EK[16]);
      decrypt_round(C, B, A, D, EK[15], EK[14]);
      decrypt_round(D, C, B, A, EK[13], EK[12]);
      decrypt_round(A, D, C, B, EK[11], EK[10]);
      decrypt_round(B, A, D, C, EK[ 9], EK[ 8]);
      decrypt_round(C, B, A, D, EK[ 7], EK[ 6]);
      decrypt_round(D, C, B, A, EK[ 5], EK[ 4]);

      reverse_mix(A, B, C, D);

      A -= EK[3]; B -= EK[2]; C -= EK[1]; D -= EK[0];

      store_le(out, D, C, B, A);

      in += BLOCK_SIZE;
      out += BLOCK_SIZE;
      }
   }

/*
* MARS Key Schedule
*/
void MARS::key_schedule(const byte key[], u32bit length)
   {
   SecureBuffer<u32bit, 15> T;
   for(u32bit j = 0; j != length / 4; ++j)
      T[j] = load_le<u32bit>(key, j);
   T[length / 4] = length / 4;

   for(u32bit j = 0; j != 4; ++j)
      {
      T[ 0] ^= rotate_left(T[ 8] ^ T[13], 3) ^ (j     );
      T[ 1] ^= rotate_left(T[ 9] ^ T[14], 3) ^ (j +  4);
      T[ 2] ^= rotate_left(T[10] ^ T[ 0], 3) ^ (j +  8);
      T[ 3] ^= rotate_left(T[11] ^ T[ 1], 3) ^ (j + 12);
      T[ 4] ^= rotate_left(T[12] ^ T[ 2], 3) ^ (j + 16);
      T[ 5] ^= rotate_left(T[13] ^ T[ 3], 3) ^ (j + 20);
      T[ 6] ^= rotate_left(T[14] ^ T[ 4], 3) ^ (j + 24);
      T[ 7] ^= rotate_left(T[ 0] ^ T[ 5], 3) ^ (j + 28);
      T[ 8] ^= rotate_left(T[ 1] ^ T[ 6], 3) ^ (j + 32);
      T[ 9] ^= rotate_left(T[ 2] ^ T[ 7], 3) ^ (j + 36);
      T[10] ^= rotate_left(T[ 3] ^ T[ 8], 3) ^ (j + 40);
      T[11] ^= rotate_left(T[ 4] ^ T[ 9], 3) ^ (j + 44);
      T[12] ^= rotate_left(T[ 5] ^ T[10], 3) ^ (j + 48);
      T[13] ^= rotate_left(T[ 6] ^ T[11], 3) ^ (j + 52);
      T[14] ^= rotate_left(T[ 7] ^ T[12], 3) ^ (j + 56);

      for(u32bit k = 0; k != 4; ++k)
         {
         T[ 0] = rotate_left(T[ 0] + SBOX[T[14] % 512], 9);
         T[ 1] = rotate_left(T[ 1] + SBOX[T[ 0] % 512], 9);
         T[ 2] = rotate_left(T[ 2] + SBOX[T[ 1] % 512], 9);
         T[ 3] = rotate_left(T[ 3] + SBOX[T[ 2] % 512], 9);
         T[ 4] = rotate_left(T[ 4] + SBOX[T[ 3] % 512], 9);
         T[ 5] = rotate_left(T[ 5] + SBOX[T[ 4] % 512], 9);
         T[ 6] = rotate_left(T[ 6] + SBOX[T[ 5] % 512], 9);
         T[ 7] = rotate_left(T[ 7] + SBOX[T[ 6] % 512], 9);
         T[ 8] = rotate_left(T[ 8] + SBOX[T[ 7] % 512], 9);
         T[ 9] = rotate_left(T[ 9] + SBOX[T[ 8] % 512], 9);
         T[10] = rotate_left(T[10] + SBOX[T[ 9] % 512], 9);
         T[11] = rotate_left(T[11] + SBOX[T[10] % 512], 9);
         T[12] = rotate_left(T[12] + SBOX[T[11] % 512], 9);
         T[13] = rotate_left(T[13] + SBOX[T[12] % 512], 9);
         T[14] = rotate_left(T[14] + SBOX[T[13] % 512], 9);
         }

      EK[10*j + 0] = T[ 0]; EK[10*j + 1] = T[ 4]; EK[10*j + 2] = T[ 8];
      EK[10*j + 3] = T[12]; EK[10*j + 4] = T[ 1]; EK[10*j + 5] = T[ 5];
      EK[10*j + 6] = T[ 9]; EK[10*j + 7] = T[13]; EK[10*j + 8] = T[ 2];
      EK[10*j + 9] = T[ 6];
      }

   for(u32bit j = 5; j != 37; j += 2)
      {
      u32bit key3 = EK[j] & 3;
      EK[j] |= 3;
      EK[j] ^= rotate_left(SBOX[265 + key3], EK[j-1] % 32) & gen_mask(EK[j]);
      }
   }

}