sbtools: add forgotten file

Change-Id: I701a301efa369c9e1247e10d226ba69e6064d1b2

1 files changed, 97 insertions, 0 deletions

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 <stdlib.h>
+#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]);
+}
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