diff options
Diffstat (limited to 'src/mars.cpp')
| -rw-r--r-- | src/mars.cpp | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/src/mars.cpp b/src/mars.cpp new file mode 100644 index 000000000..06b143e72 --- /dev/null +++ b/src/mars.cpp @@ -0,0 +1,287 @@ +/************************************************* +* MARS Source File * +* (C) 1999-2006 The Botan Project * +*************************************************/ + +#include <botan/mars.h> +#include <botan/bit_ops.h> + +namespace Botan { + +namespace { + +/************************************************* +* 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::enc(const byte in[], byte out[]) const + { + u32bit A = make_u32bit(in[ 3], in[ 2], in[ 1], in[ 0]) + EK[0], + B = make_u32bit(in[ 7], in[ 6], in[ 5], in[ 4]) + EK[1], + C = make_u32bit(in[11], in[10], in[ 9], in[ 8]) + EK[2], + D = make_u32bit(in[15], in[14], in[13], in[12]) + EK[3]; + + forward_mix(A, B, C, D); + + encrypt_round(A, B, C, D, 0); + encrypt_round(B, C, D, A, 1); + encrypt_round(C, D, A, B, 2); + encrypt_round(D, A, B, C, 3); + encrypt_round(A, B, C, D, 4); + encrypt_round(B, C, D, A, 5); + encrypt_round(C, D, A, B, 6); + encrypt_round(D, A, B, C, 7); + + encrypt_round(A, D, C, B, 8); + encrypt_round(B, A, D, C, 9); + encrypt_round(C, B, A, D, 10); + encrypt_round(D, C, B, A, 11); + encrypt_round(A, D, C, B, 12); + encrypt_round(B, A, D, C, 13); + encrypt_round(C, B, A, D, 14); + encrypt_round(D, C, B, A, 15); + + reverse_mix(A, B, C, D); + + A -= EK[36]; B -= EK[37]; C -= EK[38]; D -= EK[39]; + + out[ 0] = get_byte(3, A); out[ 1] = get_byte(2, A); + out[ 2] = get_byte(1, A); out[ 3] = get_byte(0, A); + out[ 4] = get_byte(3, B); out[ 5] = get_byte(2, B); + out[ 6] = get_byte(1, B); out[ 7] = get_byte(0, B); + out[ 8] = get_byte(3, C); out[ 9] = get_byte(2, C); + out[10] = get_byte(1, C); out[11] = get_byte(0, C); + out[12] = get_byte(3, D); out[13] = get_byte(2, D); + out[14] = get_byte(1, D); out[15] = get_byte(0, D); + } + +/************************************************* +* MARS Decryption * +*************************************************/ +void MARS::dec(const byte in[], byte out[]) const + { + u32bit D = make_u32bit(in[ 3], in[ 2], in[ 1], in[ 0]) + EK[36], + C = make_u32bit(in[ 7], in[ 6], in[ 5], in[ 4]) + EK[37], + B = make_u32bit(in[11], in[10], in[ 9], in[ 8]) + EK[38], + A = make_u32bit(in[15], in[14], in[13], in[12]) + EK[39]; + + forward_mix(A, B, C, D); + + decrypt_round(A, B, C, D, 15); + decrypt_round(B, C, D, A, 14); + decrypt_round(C, D, A, B, 13); + decrypt_round(D, A, B, C, 12); + decrypt_round(A, B, C, D, 11); + decrypt_round(B, C, D, A, 10); + decrypt_round(C, D, A, B, 9); + decrypt_round(D, A, B, C, 8); + + decrypt_round(A, D, C, B, 7); + decrypt_round(B, A, D, C, 6); + decrypt_round(C, B, A, D, 5); + decrypt_round(D, C, B, A, 4); + decrypt_round(A, D, C, B, 3); + decrypt_round(B, A, D, C, 2); + decrypt_round(C, B, A, D, 1); + decrypt_round(D, C, B, A, 0); + + reverse_mix(A, B, C, D); + + A -= EK[3]; B -= EK[2]; C -= EK[1]; D -= EK[0]; + + out[ 0] = get_byte(3, D); out[ 1] = get_byte(2, D); + out[ 2] = get_byte(1, D); out[ 3] = get_byte(0, D); + out[ 4] = get_byte(3, C); out[ 5] = get_byte(2, C); + out[ 6] = get_byte(1, C); out[ 7] = get_byte(0, C); + out[ 8] = get_byte(3, B); out[ 9] = get_byte(2, B); + out[10] = get_byte(1, B); out[11] = get_byte(0, B); + out[12] = get_byte(3, A); out[13] = get_byte(2, A); + out[14] = get_byte(1, A); out[15] = get_byte(0, A); + } + +/************************************************* +* MARS Forward Mixing Operation * +*************************************************/ +void MARS::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 MARS::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); + } + } + +/************************************************* +* MARS Encryption Round * +*************************************************/ +void MARS::encrypt_round(u32bit& A, u32bit& B, u32bit& C, u32bit& D, + u32bit round) const + { + u32bit X, Y, Z; + X = A + EK[2*round + 4]; + A = rotate_left(A, 13); + Y = A * EK[2*round + 5]; + 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 * +*************************************************/ +void MARS::decrypt_round(u32bit& A, u32bit& B, u32bit& C, u32bit& D, + u32bit round) const + { + u32bit X, Y, Z; + Y = A * EK[2*round + 5]; + A = rotate_right(A, 13); + X = A + EK[2*round + 4]; + 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 Key Schedule * +*************************************************/ +void MARS::key(const byte key[], u32bit length) + { + SecureBuffer<u32bit, 15> T; + for(u32bit j = 0; j != length / 4; ++j) + T[j] = make_u32bit(key[4*j+3], key[4*j+2], key[4*j+1], key[4*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]); + } + } + +} |