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author | Amaury Pouly <amaury.pouly@gmail.com> | 2012-11-29 17:29:13 +0100 |
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committer | Amaury Pouly <amaury.pouly@gmail.com> | 2012-11-29 17:30:54 +0100 |
commit | d66c16749a5c07aadcd0eb97b9340d7fa5ea26b0 (patch) | |
tree | 4c1b30ca5073cf2f6f7a227715fca557fbf39999 /utils/samsungtools/samsung.c | |
parent | ee36a396cd1619585a83803630db2d79b6cbefbd (diff) | |
download | rockbox-d66c16749a5c07aadcd0eb97b9340d7fa5ea26b0.tar.gz rockbox-d66c16749a5c07aadcd0eb97b9340d7fa5ea26b0.zip |
Introduce samsungtools to decrypt samsung firmware
Samsung provides many firmware upgrade in the format of a .dat
file, at least for nearly all YP's (checked for Q2, R0, T10, Z5).
This is a simple cyclic xor which a fixed key, a md5 sum and a
header specifying the model/version/region.
Change-Id: Ib0461a74196383189fd2d8162da444a85a229c60
Diffstat (limited to 'utils/samsungtools/samsung.c')
-rw-r--r-- | utils/samsungtools/samsung.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/utils/samsungtools/samsung.c b/utils/samsungtools/samsung.c new file mode 100644 index 0000000000..decf34f208 --- /dev/null +++ b/utils/samsungtools/samsung.c @@ -0,0 +1,127 @@ +/*************************************************************************** + * __________ __ ___. + * 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 "samsung.h" +#include <openssl/md5.h> +#include <string.h> +#include <stdlib.h> + +#ifndef MIN +#define MIN(a,b) ((a) < (b) ? (a) : (b)) +#endif + +static uint8_t g_yp_key[128] = +{ + 0xa3, 0x04, 0xb9, 0xcd, 0x34, 0x13, 0x4a, 0x19, 0x19, 0x35, 0xdf, 0xbb, 0x8f, 0x3d, 0x7f, 0x09, + 0x42, 0x3c, 0x96, 0xc6, 0x41, 0xa9, 0x95, 0xf1, 0xd0, 0xac, 0x16, 0x37, 0x57, 0x1f, 0x28, 0xe7, + 0x0b, 0xc2, 0x12, 0x09, 0x39, 0x42, 0xd2, 0x96, 0xf5, 0x00, 0xd2, 0x23, 0xa4, 0x24, 0xe2, 0x8e, + 0x50, 0x3c, 0x6e, 0x23, 0xeb, 0x68, 0xed, 0x31, 0xb7, 0xee, 0xc0, 0xc7, 0x09, 0xf8, 0x0e, 0x9d, + 0x51, 0xed, 0x17, 0x95, 0x64, 0x09, 0xe0, 0xf9, 0xf0, 0xef, 0x86, 0xc0, 0x04, 0x46, 0x89, 0x8a, + 0x6e, 0x27, 0x69, 0xde, 0xc7, 0x9d, 0x1e, 0xee, 0x3c, 0x3f, 0x17, 0x05, 0x44, 0xbb, 0xbb, 0x1d, + 0x3d, 0x5d, 0x6e, 0xf2, 0xcf, 0x15, 0xd6, 0x3c, 0xcc, 0x7d, 0x67, 0x1a, 0xb8, 0xd2, 0x1b, 0x54, + 0x97, 0xa2, 0x58, 0x58, 0xf7, 0x4e, 0x5e, 0x50, 0x42, 0x69, 0xdc, 0xe7, 0x3a, 0x87, 0x2e, 0x22 +}; + +static void cyclic_xor(void *data, int datasize, void *xor, int xorsize) +{ + for(int i = 0; i < datasize; i++) + *(uint8_t *)(data + i) ^= *(uint8_t *)(xor + (i % xorsize)); +} + +struct samsung_firmware_t *samsung_read(samsung_read_t read, + samsung_printf_t printf, void *user, enum samsung_error_t *err) +{ + struct yp_header_t yp_hdr; + struct yp_md5_t yp_md5; + + /* read and check header */ + if(read(user, 0, &yp_hdr, sizeof(yp_hdr)) != sizeof(yp_hdr)) + { + printf(user, true, "Cannot read YP header\n"); + *err = SAMSUNG_READ_ERROR; + return NULL; + } + if(strncmp(yp_hdr.signature, YP_SIGNATURE, sizeof(yp_hdr.signature)) != 0) + { + printf(user, true, "Bad YP signature\n"); + *err = SAMSUNG_FORMAT_ERROR; + return NULL; + } + + printf(user, false, "Model: %s\n", yp_hdr.model); + printf(user, false, "Version: %s %s %s\n", yp_hdr.version, yp_hdr.region, yp_hdr.extra); + + /* allocate and read data */ + struct samsung_firmware_t *fw = malloc(sizeof(struct samsung_firmware_t)); + memset(fw, 0, sizeof(struct samsung_firmware_t)); + fw->data_size = yp_hdr.datasize; + fw->data = malloc(fw->data_size); + strncpy(fw->version, yp_hdr.version, sizeof(yp_hdr.version)); + strncpy(fw->region, yp_hdr.region, sizeof(yp_hdr.region)); + strncpy(fw->extra, yp_hdr.extra, sizeof(yp_hdr.extra)); + strncpy(fw->model, yp_hdr.model, sizeof(yp_hdr.model)); + + if(read(user, sizeof(yp_hdr), fw->data, fw->data_size) != fw->data_size) + { + printf(user, true, "Cannot read data\n"); + *err = SAMSUNG_READ_ERROR; + samsung_free(fw); + return NULL; + } + + /* read and check MD5 */ + if(read(user, yp_hdr.datasize + sizeof(yp_hdr), &yp_md5, sizeof(yp_md5)) != sizeof(yp_md5)) + { + printf(user, true, "Cannot read MD5 sum\n"); + *err = SAMSUNG_READ_ERROR; + samsung_free(fw); + return NULL; + } + + uint8_t actual_md5[MD5_DIGEST_LENGTH]; + MD5_CTX c; + MD5_Init(&c); + MD5_Update(&c, fw->data, fw->data_size); + MD5_Final(actual_md5, &c); + + if(memcmp(actual_md5, yp_md5.md5, MD5_DIGEST_LENGTH) != 0) + { + printf(user, true, "MD5 mismatch\n"); + *err = SAMSUNG_MD5_ERROR; + samsung_free(fw); + return NULL; + } + + /* decrypt */ + cyclic_xor(fw->data, fw->data_size, g_yp_key, sizeof(g_yp_key)); + + /* success ! */ + *err = SAMSUNG_SUCCESS; + return fw; +} + +void samsung_free(struct samsung_firmware_t *fw) +{ + if(fw) + { + free(fw->data); + free(fw); + } +} |