/* * SAFER-SK * (C) 1999-2009 Jack Lloyd * * Distributed under the terms of the Botan license */ #include #include #include #include namespace Botan { /* * SAFER-SK Encryption */ void SAFER_SK::encrypt_n(const byte in[], byte out[], size_t blocks) const { for(size_t i = 0; i != blocks; ++i) { byte A = in[0], B = in[1], C = in[2], D = in[3], E = in[4], F = in[5], G = in[6], H = in[7], X, Y; for(size_t j = 0; j != 16*ROUNDS; j += 16) { A = EXP[A ^ EK[j ]]; B = LOG[B + EK[j+1]]; C = LOG[C + EK[j+2]]; D = EXP[D ^ EK[j+3]]; E = EXP[E ^ EK[j+4]]; F = LOG[F + EK[j+5]]; G = LOG[G + EK[j+6]]; H = EXP[H ^ EK[j+7]]; A += EK[j+ 8]; B ^= EK[j+ 9]; C ^= EK[j+10]; D += EK[j+11]; E += EK[j+12]; F ^= EK[j+13]; G ^= EK[j+14]; H += EK[j+15]; B += A; D += C; F += E; H += G; A += B; C += D; E += F; G += H; C += A; G += E; D += B; H += F; A += C; E += G; B += D; F += H; H += D; Y = D + H; D = B + F; X = B + D; B = A + E; A += B; F = C + G; E = C + F; C = X; G = Y; } out[0] = A ^ EK[16*ROUNDS+0]; out[1] = B + EK[16*ROUNDS+1]; out[2] = C + EK[16*ROUNDS+2]; out[3] = D ^ EK[16*ROUNDS+3]; out[4] = E ^ EK[16*ROUNDS+4]; out[5] = F + EK[16*ROUNDS+5]; out[6] = G + EK[16*ROUNDS+6]; out[7] = H ^ EK[16*ROUNDS+7]; in += block_size(); out += block_size(); } } /* * SAFER-SK Decryption */ void SAFER_SK::decrypt_n(const byte in[], byte out[], size_t blocks) const { for(size_t i = 0; i != blocks; ++i) { byte A = in[0], B = in[1], C = in[2], D = in[3], E = in[4], F = in[5], G = in[6], H = in[7]; A ^= EK[16*ROUNDS+0]; B -= EK[16*ROUNDS+1]; C -= EK[16*ROUNDS+2]; D ^= EK[16*ROUNDS+3]; E ^= EK[16*ROUNDS+4]; F -= EK[16*ROUNDS+5]; G -= EK[16*ROUNDS+6]; H ^= EK[16*ROUNDS+7]; for(s32bit j = 16*(ROUNDS-1); j >= 0; j -= 16) { byte T = E; E = B; B = C; C = T; T = F; F = D; D = G; G = T; A -= E; B -= F; C -= G; D -= H; E -= A; F -= B; G -= C; H -= D; A -= C; E -= G; B -= D; F -= H; C -= A; G -= E; D -= B; H -= F; A -= B; C -= D; E -= F; G -= H; B -= A; D -= C; F -= E; H -= G; A = LOG[A - EK[j+8 ] + 256]; B = EXP[B ^ EK[j+9 ]]; C = EXP[C ^ EK[j+10]]; D = LOG[D - EK[j+11] + 256]; E = LOG[E - EK[j+12] + 256]; F = EXP[F ^ EK[j+13]]; G = EXP[G ^ EK[j+14]]; H = LOG[H - EK[j+15] + 256]; A ^= EK[j+0]; B -= EK[j+1]; C -= EK[j+2]; D ^= EK[j+3]; E ^= EK[j+4]; F -= EK[j+5]; G -= EK[j+6]; H ^= EK[j+7]; } out[0] = A; out[1] = B; out[2] = C; out[3] = D; out[4] = E; out[5] = F; out[6] = G; out[7] = H; in += block_size(); out += block_size(); } } /* * SAFER-SK Key Schedule */ void SAFER_SK::key_schedule(const byte key[], size_t) { SecureVector KB(18); for(size_t i = 0; i != 8; ++i) { KB[ 8] ^= KB[i] = rotate_left(key[i], 5); KB[17] ^= KB[i+9] = EK[i] = key[i+8]; } for(size_t i = 0; i != ROUNDS; ++i) { for(size_t j = 0; j != 18; ++j) KB[j] = rotate_left(KB[j], 6); for(size_t j = 0; j != 16; ++j) EK[16*i+j+8] = KB[KEY_INDEX[16*i+j]] + BIAS[16*i+j]; } } /* * Return the name of this type */ std::string SAFER_SK::name() const { return "SAFER-SK(" + to_string(ROUNDS) + ")"; } /* * Return a clone of this object */ BlockCipher* SAFER_SK::clone() const { return new SAFER_SK(ROUNDS); } /* * SAFER-SK Constructor */ SAFER_SK::SAFER_SK(size_t rounds) : BlockCipher(8, 16), EK(16 * rounds + 8), ROUNDS(rounds) { if(ROUNDS > 13 || ROUNDS == 0) throw Invalid_Argument(name() + ": Invalid number of rounds"); } }