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authorDave Chapman <dave@dchapman.com>2009-10-10 11:46:23 +0000
committerDave Chapman <dave@dchapman.com>2009-10-10 11:46:23 +0000
commit4fe2ee02215730c2217135ef1e6dd4585a0c2439 (patch)
tree46a481cd84da1ccf6524c904789ee5bdf2322512 /apps/plugins/crypt_firmware.c
parente51dbc0f4f4779f6d0ea510b487c79faca3c128f (diff)
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Add crypt_firmware plugin for Nano2G - this uses the hardware crypto unit to encrypt (or decrypt) a firmware image for writing to a Nano 2G's firmware partition with ipodpatcher (patch for ipodpatcher is at FS#10609). Also introduce BOOTFILE_EXT2 define for an alternative firmware file extension and add .ipodx for the Nano 2G (.ipod is for unencrypted images, similar to older ipods, and .ipodx is for encrypted images and include the 2KB hash block and modelname 'nn2x').
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@23068 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/plugins/crypt_firmware.c')
-rw-r--r--apps/plugins/crypt_firmware.c346
1 files changed, 346 insertions, 0 deletions
diff --git a/apps/plugins/crypt_firmware.c b/apps/plugins/crypt_firmware.c
new file mode 100644
index 0000000000..6bfeeabe00
--- /dev/null
+++ b/apps/plugins/crypt_firmware.c
@@ -0,0 +1,346 @@
+/***************************************************************************
+ *
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ *
+ * $Id: $
+ *
+ * Rockbox plugin copyright (C) 2009 Dave Chapman.
+ * Based on encryption code (C) 2009 Michael Sparmann
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/*
+
+ This viewer plugin is for the encryption/decryption of iPod Nano
+ (2nd generation) firmware images using the hardware AES crypto unit
+ in such devices.
+
+ Encrypted images are stored with the modelname "nn2x" and extension
+ ".ipodx" Unencrypted images use "nn2g" and ".ipod".
+
+ Heavily based on Payloads/CryptFirmware/main.c from iBugger.
+
+ The (C) from that file is as follows:
+
+ Copyright 2009 TheSeven
+
+ This file is part of TheSeven's iBugger.
+
+ TheSeven's iBugger 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.
+
+ TheSeven's iBugger 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with TheSeven's iBugger. If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#include "plugin.h"
+
+PLUGIN_HEADER
+
+static void aes_encrypt(void* data, uint32_t size)
+{
+ uint32_t ptr, i;
+ uint32_t go = 1;
+ PWRCONEXT &= ~0x400;
+ AESTYPE = 1;
+ AESUNKREG0 = 1;
+ AESUNKREG0 = 0;
+ AESCONTROL = 1;
+ AESKEYLEN = 9;
+ AESOUTSIZE = size;
+ AESAUXSIZE = 0x10;
+ AESINSIZE = 0x10;
+ AESSIZE3 = 0x10;
+ for (ptr = 0; ptr < (size >> 2); ptr += 4)
+ {
+ AESOUTADDR = (uint32_t)data + (ptr << 2);
+ AESINADDR = (uint32_t)data + (ptr << 2);
+ AESAUXADDR = (uint32_t)data + (ptr << 2);
+ if (ptr != 0)
+ for (i = 0; i < 4; i++)
+ ((uint32_t*)data)[ptr + i] ^= ((uint32_t*)data)[ptr + i - 4];
+ AESSTATUS = 6;
+ AESGO = go;
+ go = 3;
+ while ((AESSTATUS & 6) == 0);
+ }
+ AESCONTROL = 0;
+ PWRCONEXT |= 0x400;
+}
+
+static void aes_decrypt(void* data, uint32_t size)
+{
+ uint32_t ptr, i;
+ uint32_t go = 1;
+ PWRCONEXT &= ~0x400;
+ AESTYPE = 1;
+ AESUNKREG0 = 1;
+ AESUNKREG0 = 0;
+ AESCONTROL = 1;
+ AESKEYLEN = 8;
+ AESOUTSIZE = size;
+ AESAUXSIZE = 0x10;
+ AESINSIZE = 0x10;
+ AESSIZE3 = 0x10;
+ for (ptr = (size >> 2) - 4; ; ptr -= 4)
+ {
+ AESOUTADDR = (uint32_t)data + (ptr << 2);
+ AESINADDR = (uint32_t)data + (ptr << 2);
+ AESAUXADDR = (uint32_t)data + (ptr << 2);
+ AESSTATUS = 6;
+ AESGO = go;
+ go = 3;
+ while ((AESSTATUS & 6) == 0);
+ if (ptr == 0) break;
+ for (i = 0; i < 4; i++)
+ ((uint32_t*)data)[ptr + i] ^= ((uint32_t*)data)[ptr + i - 4];
+ }
+ AESCONTROL = 0;
+ PWRCONEXT |= 0x400;
+}
+
+static void calc_hash(uint32_t* data, uint32_t size, uint32_t* result)
+{
+ uint32_t ptr, i;
+ uint32_t ctrl = 2;
+
+ PWRCONEXT &= ~0x4;
+
+ for (ptr = 0; ptr < (size >> 2); ptr += 0x10)
+ {
+ for (i = 0; i < 0x10; i++) HASHDATAIN[i] = data[ptr + i];
+ HASHCTRL = ctrl;
+ ctrl = 0xA;
+ while ((HASHCTRL & 1) != 0);
+ }
+ for (i = 0; i < 5; i ++) result[i] = HASHRESULT[i];
+
+ PWRCONEXT |= 0x4;
+}
+
+static uint32_t get_uint32be(unsigned char* buf)
+{
+ return (uint32_t)((buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3]);
+}
+
+static void put_uint32be(unsigned char* buf, uint32_t x)
+{
+ buf[0] = (x & 0xff000000) >> 24;
+ buf[1] = (x & 0xff0000) >> 16;
+ buf[2] = (x & 0xff00) >> 8;
+ buf[3] = x & 0xff;
+}
+
+static uint32_t calc_checksum(uint32_t sum, unsigned char* buf, int len)
+{
+ int i;
+
+ for (i = 0; i < len ; i++) {
+ sum += buf[i];
+ }
+
+ return sum;
+}
+
+enum plugin_status plugin_start(const void* parameter)
+{
+ int fd;
+ int length;
+ int n;
+ ssize_t buf_size;
+ uint32_t* buf;
+ int size;
+ uint32_t sum;
+ uint32_t hash[0x200];
+ char outputfilename[MAX_PATH];
+
+ fd = rb->open(parameter,O_RDONLY);
+
+ if (fd < 0) {
+ rb->splash(HZ*2, "Cannot open file");
+ return PLUGIN_ERROR;
+ }
+
+ length = rb->filesize(fd);
+
+ if (length < 12) {
+ rb->splash(HZ*2, "File too small");
+ return PLUGIN_ERROR;
+ }
+
+ if (length > buf_size) {
+ rb->splash(HZ*2, "File too big");
+ return PLUGIN_ERROR;
+ }
+
+ /* Get the audio buffer */
+ buf = rb->plugin_get_audio_buffer((size_t *)&buf_size);
+
+ /* Use uncached alias for buf - equivalent to buf |= 0x40000000 */
+ buf += 0x10000000;
+
+ n = rb->read(fd, buf, length);
+ if (n < length) {
+ rb->splash(HZ*2, "Cannot read file");
+ return PLUGIN_ERROR;
+ }
+ rb->close(fd);
+
+ size = length - 8; /* Size of firmware image */
+
+ if (calc_checksum(MODEL_NUMBER, (unsigned char*)(buf + 2), size) !=
+ get_uint32be((unsigned char*)buf)) {
+ rb->splash(HZ*2, "Bad checksum in input file");
+ return PLUGIN_ERROR;
+ }
+
+ n = rb->strlen(parameter);
+ if (memcmp(buf+1,"nn2g",4)==0) {
+ /* Encrypting - Input file should be .ipod, output file is .ipodx */
+
+ if ((n < 6) || (rb->strcmp(parameter+n-5,".ipod") != 0)) {
+ rb->splash(HZ*2, "Input filename must be .ipod");
+ return PLUGIN_ERROR;
+ }
+
+ if (n + 2 > MAX_PATH) {
+ rb->splash(HZ*2, "Filename too long");
+ return PLUGIN_ERROR;
+ }
+
+ size = (size + 0x3f) & ~0x3f; /* Pad to multiple of 64 bytes */
+ if (size > (length - 8)) {
+ rb->memset(&buf[length/4], 0, size - (length - 8));
+ }
+
+ rb->strlcpy(outputfilename, parameter, MAX_PATH);
+ outputfilename[n] = 'x';
+ outputfilename[n+1] = 0;
+
+ /* Everything is OK, now do the encryption */
+
+ /* 1 - Calculate hashes */
+
+ rb->memset(hash, 0, sizeof(hash));
+
+ hash[1] = 2;
+ hash[2] = 1;
+ hash[3] = 0x40;
+ hash[5] = size;
+
+ calc_hash(buf + 2, size, &hash[7]);
+ calc_hash(hash, 0x200, &hash[0x75]);
+
+ /* 2 - Do the encryption */
+
+ rb->splash(0, "Encrypting...");
+ aes_encrypt(buf + 2, size);
+
+ /* 3 - Update the Rockbox header */
+
+ sum = calc_checksum(MODEL_NUMBER, (unsigned char*)hash, sizeof(hash));
+ sum = calc_checksum(sum, (unsigned char*)(buf + 2), size);
+ put_uint32be((unsigned char*)buf, sum);
+ memcpy(buf + 1, "nn2x", 4);
+
+ /* 4 - Write to disk */
+ fd = rb->open(outputfilename,O_WRONLY|O_CREAT|O_TRUNC);
+
+ if (fd < 0) {
+ rb->splash(HZ*2, "Could not open output file");
+ return PLUGIN_ERROR;
+ }
+
+ n = rb->write(fd, buf, 8);
+ n = rb->write(fd, hash, sizeof(hash));
+ n = rb->write(fd, buf + 2, size);
+
+ rb->close(fd);
+ } else if (memcmp(buf + 1,"nn2x",4)==0) {
+ /* Decrypting - Input file should be .ipodx, output file is .ipod */
+
+ if ((n < 7) || (rb->strcmp(parameter+n-6,".ipodx") != 0)) {
+ rb->splash(HZ*2, "Input filename must be .ipodx");
+ return PLUGIN_ERROR;
+ }
+
+ rb->strlcpy(outputfilename, parameter, MAX_PATH);
+ outputfilename[n-1] = 0; /* Remove "x" at end of filename */
+
+ /* Everything is OK, now do the decryption */
+
+ size -= 0x800; /* Remove hash size from firmware size */
+
+ /* 1 - Decrypt */
+
+ rb->splash(0, "Decrypting...");
+
+ aes_decrypt(&buf[0x202], size);
+
+ /* 2 - Calculate hashes to verify decryption */
+
+ rb->lcd_clear_display();
+ rb->splash(0, "Calculating hash...");
+
+ rb->memset(hash, 0, sizeof(hash));
+
+ hash[1] = 2;
+ hash[2] = 1;
+ hash[3] = 0x40;
+ hash[5] = size;
+
+ calc_hash(&buf[0x202], size, &hash[7]);
+ calc_hash(hash, 0x200, &hash[0x75]);
+
+ if ((memcmp(hash + 7, buf + 9, 20) != 0) ||
+ (memcmp(hash + 75, buf + 77, 20) != 0)) {
+ rb->splash(HZ*2, "Decryption failed - bad hash");
+ return PLUGIN_ERROR;
+ }
+
+ /* 3 - Update the Rockbox header */
+
+ sum = calc_checksum(MODEL_NUMBER, (unsigned char*)(&buf[0x202]), size);
+ put_uint32be((unsigned char*)buf, sum);
+ memcpy(buf + 1, "nn2g", 4);
+
+ /* 4 - Write to disk */
+ fd = rb->open(outputfilename,O_WRONLY|O_CREAT|O_TRUNC);
+
+ if (fd < 0) {
+ rb->splash(HZ*2, "Could not open output file");
+ return PLUGIN_ERROR;
+ }
+
+ n = rb->write(fd, buf, 8);
+ n = rb->write(fd, &buf[0x202], size);
+
+ rb->close(fd);
+ } else {
+ rb->splash(HZ*2,"Invalid input file");
+ return PLUGIN_ERROR;
+ }
+
+ return PLUGIN_OK;
+}