From c3a7190d7809dbe4cf839a352dfa5f6dca8b9e53 Mon Sep 17 00:00:00 2001 From: Amaury Pouly Date: Wed, 26 Dec 2012 01:01:19 +0100 Subject: imxtools/sbtools: add crypto code for documentation purpose Change-Id: I4f3c659d65c1453b192cbce4bf6c85d882761929 --- utils/imxtools/sbtools/xorcrypt.c | 43 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/utils/imxtools/sbtools/xorcrypt.c b/utils/imxtools/sbtools/xorcrypt.c index 89dde07ddc..5ecf9208d6 100644 --- a/utils/imxtools/sbtools/xorcrypt.c +++ b/utils/imxtools/sbtools/xorcrypt.c @@ -54,6 +54,49 @@ static uint32_t do_round(union xorcrypt_key_t *key) return key->k[0]; } +static uint32_t do_unround(union xorcrypt_key_t *key) +{ + uint32_t k7 = key->k[6]; + uint32_t k2 = key->k[1]; + uint32_t k11 = key->k[10] >> 31 | key->k[10] << 1; + uint32_t k0 = key->k[0]; + key->k[0] = key->k[15]; + key->k[15] = key->k[14]; + key->k[14] = key->k[13]; + key->k[13] = key->k[12]; + key->k[12] = key->k[11] ^ k11; + key->k[11] = k11; + key->k[10] = key->k[9]; + key->k[9] = key->k[8]; + key->k[8] = key->k[7] ^ k7; + key->k[7] = key->k[6]; + key->k[6] = key->k[5]; + key->k[5] = key->k[4]; + key->k[4] = key->k[3]; + key->k[3] = key->k[2] ^ k2; + key->k[2] = key->k[1]; + key->k[1] = k0 ^ key->k[0] ^ key->k[5] ^ key->k[3] ^ key->k[7] ^ key->k[11] ^ key->k[13]; + return 0; +} + +static void test_round(union xorcrypt_key_t keys[2]) +{ + union xorcrypt_key_t save[2]; + memcpy(save, keys, sizeof(save)); + do_round(keys); + do_unround(keys); + if(memcmp(save, keys, sizeof(save))) + { + printf("Mismatch\n"); + for(int i = 0; i < 16; i++) + printf(" %s%08x", save[0].k[i] == keys[0].k[i] ? YELLOW : RED, save[0].k[i]); + printf("\n"); + for(int i = 0; i < 16; i++) + printf(" %s%08x", save[0].k[i] == keys[0].k[i] ? YELLOW : RED, keys[0].k[i]); + printf("\n"); + } +} + uint32_t xor_encrypt(union xorcrypt_key_t keys[2], void *_data, int size) { if(size % 4) -- cgit v1.2.3