From 9716d1f1f964a29c5087a2861e2b94afd140dcbb Mon Sep 17 00:00:00 2001 From: Amaury Pouly Date: Tue, 27 Nov 2012 00:01:35 +0100 Subject: [PATCH] sbtools: add forgotten file Change-Id: I701a301efa369c9e1247e10d226ba69e6064d1b2 --- utils/imxtools/sbtools/xorcrypt.c | 97 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 utils/imxtools/sbtools/xorcrypt.c diff --git a/utils/imxtools/sbtools/xorcrypt.c b/utils/imxtools/sbtools/xorcrypt.c new file mode 100644 index 0000000000..89dde07ddc --- /dev/null +++ b/utils/imxtools/sbtools/xorcrypt.c @@ -0,0 +1,97 @@ +/*************************************************************************** + * __________ __ ___. + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * $Id$ + * + * Copyright (C) 2012 Amaury Pouly + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ****************************************************************************/ +#include "crypto.h" +#include +#include "misc.h" + +static uint32_t do_round(union xorcrypt_key_t *key) +{ + uint32_t k7 = key->k[7]; + uint32_t k2 = key->k[2]; + uint32_t k5_3_1 = key->k[5] ^ key->k[3] ^ key->k[1]; + key->k[1] = k2; + uint32_t k_11_7_5_3_1 = key->k[11] ^ k7 ^ k5_3_1; + key->k[2] = key->k[3] ^ k2; + key->k[3] = key->k[4]; + key->k[4] = key->k[5]; + key->k[5] = key->k[6]; + uint32_t k0 = key->k[0]; + key->k[7] = k7 ^ key->k[8]; + uint32_t k13 = key->k[13]; + key->k[8] = key->k[9]; + uint32_t k10 = key->k[10]; + key->k[6] = k7; + key->k[9] = k10; + uint32_t k11 = key->k[11]; + key->k[0] = k0 ^ k13 ^ k_11_7_5_3_1; + key->k[10] = (k11 >> 1) | (k11 << 31); + uint32_t k11_12 = k11 ^ key->k[12]; + uint32_t k14 = key->k[14]; + key->k[12] = k13; + key->k[13] = k14; + uint32_t k15 = key->k[15]; + key->k[15] = k0; + key->k[11] = k11_12; + key->k[14] = k15; + return key->k[0]; +} + +uint32_t xor_encrypt(union xorcrypt_key_t keys[2], void *_data, int size) +{ + if(size % 4) + bugp("xor_encrypt: size is not a multiple of 4 !\n"); + size /= 4; + uint32_t *data = _data; + uint32_t final_xor = 0; + for(int i = 0; i < size; i += 4) + { + uint32_t x = do_round(&keys[1]); + /* xor first key's first word with data (at most 4 words of data) */ + for(int j = i; j < i + 4 && j < size; j++) + { + keys[0].k[0] ^= data[j]; + data[j] ^= x; + } + final_xor = do_round(&keys[0]); + } + return final_xor ^ do_round(&keys[1]); +} + +uint32_t xor_decrypt(union xorcrypt_key_t keys[2], void *_data, int size) +{ + if(size % 4) + bugp("xor_decrypt: size is not a multiple of 4 !\n"); + size /= 4; + uint32_t *data = _data; + uint32_t final_xor = 0; + for(int i = 0; i < size; i += 4) + { + uint32_t x = do_round(&keys[1]); + /* xor first key's first word with data (at most 4 words of data) */ + for(int j = i; j < i + 4 && j < size; j++) + { + data[j] ^= x; + keys[0].k[0] ^= data[j]; + } + final_xor = do_round(&keys[0]); + } + return final_xor ^ do_round(&keys[1]); +} \ No newline at end of file -- 2.11.4.GIT