/* TETRA HURDLE block cipher implementation */ /* * Copyright (C) 2023 Midnight Blue B.V. * * Author: Wouter Bokslag * * SPDX-License-Identifier: AGPL-3.0+ * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . * See the COPYING file in the main directory for details. */ #include #include #include #include "hurdle.h" const uint8_t g_abHurdleSbox[256] = { 0xF4, 0x65, 0x01, 0x00, 0xBA, 0x7A, 0xA7, 0x47, 0x98, 0xDD, 0x9D, 0xAD, 0x96, 0x5D, 0xAA, 0x3D, 0x58, 0xC0, 0x72, 0xD8, 0x66, 0x4C, 0x3E, 0xE0, 0x80, 0x55, 0xDE, 0x90, 0x2A, 0x4B, 0x83, 0xA0, 0x51, 0x39, 0xED, 0x6C, 0x8A, 0x2C, 0x56, 0x60, 0x4A, 0x1F, 0xD0, 0x70, 0x6E, 0x33, 0x8B, 0x26, 0x2E, 0x6F, 0x89, 0x48, 0x5E, 0x40, 0xC3, 0xA4, 0xA9, 0xCF, 0x22, 0x50, 0xE1, 0x15, 0x0C, 0xAB, 0xD5, 0xF8, 0x5F, 0x36, 0x04, 0xA6, 0x4E, 0x92, 0x1E, 0x2B, 0x88, 0x30, 0x93, 0x45, 0x67, 0x16, 0x8C, 0x68, 0x23, 0x38, 0x61, 0x25, 0x1A, 0x81, 0x63, 0xCB, 0xC1, 0x13, 0x41, 0x37, 0x0E, 0x97, 0x5B, 0xCA, 0x57, 0x24, 0x4D, 0x17, 0xC4, 0xB9, 0xB3, 0xEF, 0x8D, 0x52, 0x32, 0x2F, 0xEC, 0x20, 0xD9, 0x11, 0xD1, 0x28, 0x79, 0xDA, 0xFB, 0xE9, 0xBB, 0x06, 0x77, 0xDB, 0xFC, 0xFE, 0xCD, 0x84, 0x1D, 0xA1, 0x54, 0x1B, 0xB0, 0xE4, 0xCC, 0x7C, 0x2D, 0x27, 0x31, 0x49, 0xF5, 0x02, 0x69, 0x53, 0x4F, 0x44, 0xDF, 0x18, 0x5C, 0x0F, 0xBC, 0x9B, 0x94, 0xBD, 0xDC, 0x0B, 0xA2, 0xC7, 0x09, 0xAC, 0xC6, 0x9F, 0x82, 0x1C, 0x05, 0x46, 0xC2, 0x34, 0x3C, 0x0D, 0x3B, 0xCE, 0xB7, 0xBE, 0x08, 0x9C, 0x6B, 0xEE, 0xE5, 0x87, 0xAF, 0xBF, 0xF2, 0xEB, 0x7B, 0x07, 0x64, 0xC5, 0xB6, 0xAE, 0x9A, 0x95, 0x35, 0xA5, 0x59, 0x12, 0x9E, 0xA3, 0xB8, 0x8E, 0x5A, 0xF7, 0x62, 0xD2, 0x3A, 0xA8, 0x7D, 0x85, 0xF6, 0xC8, 0x71, 0x29, 0xD6, 0xD7, 0x43, 0xF9, 0x78, 0x76, 0x73, 0x10, 0x91, 0x19, 0x0A, 0x99, 0xF0, 0xE6, 0x3F, 0x14, 0xF1, 0xE2, 0xB1, 0x86, 0xB4, 0xF3, 0x74, 0xFA, 0x6A, 0xB2, 0x21, 0x6D, 0xEA, 0xB5, 0xE7, 0xE3, 0xC9, 0xD3, 0x8F, 0x03, 0x75, 0xE8, 0xD4, 0x42, 0xFD, 0x7E, 0xFF, 0x7F}; #if __BYTE_ORDER == __LITTLE_ENDIAN static const uint32_t g_adwReorder[16] = { 0x00000000, 0x80000000, 0x00800000, 0x80800000, 0x00008000, 0x80008000, 0x00808000, 0x80808000, 0x00000080, 0x80000080, 0x00800080, 0x80800080, 0x00008080, 0x80008080, 0x00808080, 0x80808080 }; #else static const uint32_t g_adwReorder[16] = { 0x00000000, 0x00000080, 0x00008000, 0x00008080, 0x00800000, 0x00800080, 0x00808000, 0x00808080, 0x80000000, 0x80000080, 0x80008000, 0x80008080, 0x80800000, 0x80800080, 0x80808000, 0x80808080 }; #endif void hurdle_set_key(uint8_t *k, struct hurdle_ctx *lpContextOut) { /* Simplified key schedule by precomputing rotates and xor constants */ uint8_t abKeyBytes[256] = { k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[6], k[7], k[8], k[9], k[10], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[11], k[12], k[13], k[14], k[15], k[0], k[1], k[2], k[3], k[4], k[5], k[6], k[7], k[8], k[9], k[10]}; static const uint8_t abKeyXorConsts[256] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3C, 0xA7, 0xEC, 0x25, 0x79, 0x57, 0xDF, 0xC0, 0x38, 0x0A, 0x33, 0x1E, 0xF3, 0x8C, 0xF4, 0xF7, 0x6B, 0x78, 0x2C, 0x1D, 0x73, 0x64, 0xC1, 0x33, 0xB4, 0xFE, 0xC4, 0x22, 0x54, 0x60, 0xD1, 0x8E, 0x58, 0x66, 0xDF, 0x91, 0x87, 0x93, 0xFD, 0x94, 0x58, 0xDB, 0xBD, 0x75, 0x8B, 0xA0, 0xE9, 0x84, 0xAF, 0x5A, 0x78, 0x7D, 0xA2, 0xEA, 0xAA, 0x4B, 0x98, 0xE3, 0xB7, 0x46, 0x95, 0x53, 0x65, 0x70, 0x41, 0x05, 0x06, 0x8F, 0x32, 0xCF, 0x3C, 0x77, 0x7E, 0x9F, 0x60, 0x7B, 0x83, 0x23, 0xAE, 0x8F, 0x4B, 0xD9, 0x73, 0x45, 0x02, 0xD4, 0xFC, 0x6E, 0xB7, 0x4B, 0x36, 0x18, 0x7C, 0xBE, 0x3B, 0xCB, 0xE8, 0x5B, 0x82, 0x92, 0x32, 0x61, 0xC7, 0xBC, 0x86, 0x31, 0xF8, 0x55, 0x2A, 0xFF, 0xB1, 0xF5, 0x5D, 0x60, 0x50, 0xA3, 0x48, 0xAF, 0x8A, 0xEA, 0xC7, 0xBB, 0xC6, 0xF6, 0xA8, 0x0E, 0x66, 0xC5, 0x93, 0x2D, 0x06, 0xE2, 0xC2, 0x91, 0x29, 0x68, 0x36, 0x6C, 0xF6, 0x43, 0x93, 0xDC, 0x57, 0xBF, 0xAD, 0x8E, 0x84, 0x13, 0x15, 0xA1, 0x9C, 0x53, 0xE4, 0x5D, 0x8C, 0x8D, 0xDE, 0x8A, 0x16, 0x35, 0x6F, 0x43, 0xB1, 0xA9, 0xF4, 0x89, 0x55, 0xD6, 0x0D, 0xA7, 0xBD, 0x9A, 0xE0, 0x99, 0x55, 0x6B, 0x95, 0x53, 0x65, 0x70, 0xAF, 0x5A, 0x78, 0x7D, 0xA2, 0xEA, 0xAA, 0x4B, 0x98, 0xE3, 0xB7, 0x46, 0x66, 0xDF, 0x91, 0x87, 0x93, 0xFD, 0x94, 0x58, 0xDB, 0xBD, 0x75, 0x8B, 0xA0, 0xE9, 0x84, 0x58, 0xC1, 0x33, 0xB4, 0xFE, 0xC4, 0x22, 0x54, 0x60, 0xD1, 0x8E, 0x6B, 0x78, 0x2C, 0x1D, 0x73, 0x64, 0x1E, 0xF3, 0x8C, 0xF4, 0xF7, 0x3C, 0xA7, 0xEC, 0x25, 0x79, 0x57, 0xDF, 0xC0, 0x38, 0x0A, 0x33}; /* Xor original key byte with round- and offset-specific xor byte */ for (int i = 0; i < 256; i++) lpContextOut->abRoundKeys[i] = abKeyBytes[i] ^ abKeyXorConsts[i]; } void HURDLE_f(uint8_t abOutput[4], const uint8_t abRhs[4], const uint8_t *lpRoundKey) { #define PUSH_OUTPUT_NIBBLE(x) do { \ dwOutputBits >>= 1; \ dwOutputBits |= g_adwReorder[(x) & 0xf]; \ } while (0) uint32_t dwOutputBits = 0; uint8_t bSboxState = 0; bSboxState = g_abHurdleSbox[(abRhs[3] + lpRoundKey[15]) & 0xff]; bSboxState = g_abHurdleSbox[((abRhs[2] + lpRoundKey[14]) ^ bSboxState) & 0xff]; bSboxState = g_abHurdleSbox[((abRhs[1] + lpRoundKey[13]) ^ bSboxState) & 0xff]; bSboxState = g_abHurdleSbox[((abRhs[0] + lpRoundKey[12]) ^ bSboxState) & 0xff]; bSboxState = g_abHurdleSbox[((abRhs[3] + lpRoundKey[11]) ^ bSboxState) & 0xff]; PUSH_OUTPUT_NIBBLE(bSboxState); bSboxState = g_abHurdleSbox[((abRhs[1] + lpRoundKey[10]) ^ bSboxState) & 0xff]; PUSH_OUTPUT_NIBBLE(bSboxState); bSboxState = g_abHurdleSbox[((abRhs[2] + lpRoundKey[9]) ^ bSboxState) & 0xff]; PUSH_OUTPUT_NIBBLE(bSboxState); bSboxState = g_abHurdleSbox[((abRhs[0] + lpRoundKey[8]) ^ bSboxState) & 0xff]; PUSH_OUTPUT_NIBBLE(bSboxState); bSboxState = g_abHurdleSbox[((abRhs[1] + lpRoundKey[7]) ^ bSboxState) & 0xff]; PUSH_OUTPUT_NIBBLE(bSboxState); bSboxState = g_abHurdleSbox[((abRhs[3] + lpRoundKey[6]) ^ bSboxState) & 0xff]; PUSH_OUTPUT_NIBBLE(bSboxState); bSboxState = g_abHurdleSbox[((abRhs[0] + lpRoundKey[5]) ^ bSboxState) & 0xff]; PUSH_OUTPUT_NIBBLE(bSboxState); bSboxState = g_abHurdleSbox[((abRhs[2] + lpRoundKey[4]) ^ bSboxState) & 0xff]; PUSH_OUTPUT_NIBBLE(bSboxState); *(uint32_t *)abOutput = dwOutputBits; } void HURDLE_encrypt(uint8_t abOutput[8], const uint8_t abInput[8], struct hurdle_ctx *lpKey, uint8_t eEncryptMode) { uint32_t dwLhs, dwRhs, dwTemp; int i; /* start at first/last round key depending on encrypt/decrypt mode */ uint8_t *lpRoundKey = (eEncryptMode == HURDLE_DECRYPT) ? &lpKey->abRoundKeys[240] : lpKey->abRoundKeys; /* copy state */ dwLhs = *(uint32_t *)&abInput[0]; dwRhs = *(uint32_t *)&abInput[4]; for (i = 0; i < 16; i++) { /* Round function */ HURDLE_f((uint8_t *)&dwTemp, (uint8_t *)&dwRhs, lpRoundKey); /* perform a left-right switcharoo */ dwTemp ^= dwLhs; dwLhs = dwRhs; dwRhs = dwTemp; /* move to next/previous round key depending on encrypt/decrypt mode */ lpRoundKey += (eEncryptMode == HURDLE_DECRYPT) ? -16 : 16; } *(uint32_t *)&abOutput[0] = dwRhs; *(uint32_t *)&abOutput[4] = dwLhs; } void HURDLE_enc_cbc(uint8_t abCiphertext[16], const uint8_t abPlaintext[16], uint8_t abKey[16]) { uint8_t abIntermediate[8]; struct hurdle_ctx stCipher; hurdle_set_key(abKey, &stCipher); HURDLE_encrypt(abCiphertext, abPlaintext, &stCipher, HURDLE_ENCRYPT); *(uint32_t *)&abIntermediate[0] = *(uint32_t *)&abCiphertext[0] ^ *(uint32_t *)&abPlaintext[8]; *(uint32_t *)&abIntermediate[4] = *(uint32_t *)&abCiphertext[4] ^ *(uint32_t *)&abPlaintext[12]; HURDLE_encrypt(&abCiphertext[8], abIntermediate, &stCipher, HURDLE_ENCRYPT); } void HURDLE_dec_cts(uint8_t abPlaintext[15], const uint8_t abCiphertext[15], uint8_t abKey[16]) { uint8_t abIntermediate[16]; struct hurdle_ctx stCipher; hurdle_set_key(abKey, &stCipher); HURDLE_encrypt(&abIntermediate[8], &abCiphertext[7], &stCipher, HURDLE_DECRYPT); *(uint32_t *)&abIntermediate[0] = *(uint32_t *)&abCiphertext[0]; *(uint32_t *)&abIntermediate[4] = *(uint32_t *)&abCiphertext[4]; abIntermediate[7] = abIntermediate[15]; HURDLE_encrypt(&abIntermediate[0], &abIntermediate[0], &stCipher, HURDLE_DECRYPT); *(uint32_t *)&abIntermediate[8] ^= *(uint32_t *)&abCiphertext[0]; *(uint16_t *)&abIntermediate[12] ^= *(uint16_t *)&abCiphertext[4]; *(uint8_t *)&abIntermediate[14] ^= *(uint8_t *)&abCiphertext[6]; *(uint32_t *)&abPlaintext[0] = *(uint32_t *)&abIntermediate[0]; *(uint32_t *)&abPlaintext[4] = *(uint32_t *)&abIntermediate[4]; *(uint32_t *)&abPlaintext[8] = *(uint32_t *)&abIntermediate[8]; *(uint16_t *)&abPlaintext[12] = *(uint16_t *)&abIntermediate[12]; *(uint8_t *)&abPlaintext[14] = *(uint8_t *)&abIntermediate[14]; }