1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
*
* Copyright (C) 2013 Lorenzo Miori
*
* 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 <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <getopt.h>
#include <stdint.h>
#include <stdbool.h>
#include "common.h"
static char* output_dir = NULL;
static FILE* input_file = NULL;
static struct firmware_data fw;
static void cleanup(void)
{
for (int i = 0; i < YPR0_COMPONENTS_COUNT; i++)
{
free(fw.component_data[i]);
}
}
static void die(int error)
{
if (input_file != NULL)
fclose(input_file);
free(output_dir);
cleanup();
exit(error);
}
int main(int argc, char **argv)
{
FILE* component_handle = NULL;
FILE* rev_info_file = NULL;
char* tmp_path = malloc(MAX_PATH);
int error = 0;
bool md5sum_error = false;
memset(&fw, 0, sizeof(fw));
if (argc < 2)
{
printf("Decrypts Samsung YP-R0/YP-R1 ROM file format\n"
"Usage: fwdecrypt <ROM file path\n"
);
return 1;
}
output_dir = malloc(MAX_PATH);
output_dir[0] = '\0';
if (argc > 2)
{
strcpy(output_dir, argv[2]);
}
/* open the output file for write */
input_file = fopen(argv[1], "rb");
if (input_file == NULL)
{
fprintf(stderr, "Cannot open file for reading: %m\n");
die(SAMSUNG_READ_ERROR);
}
/* read some generic information */
join_path(tmp_path, output_dir, "RevisionInfo.txt");
rev_info_file = fopen(tmp_path, "w");
for (int i = 0; i < 5; i++)
{
char info[MAX_HEADER_LEN];
error += fgets(info, MAX_HEADER_LEN, input_file) == NULL;
printf("%s", info);
if (rev_info_file != NULL)
fprintf(rev_info_file, "%s", info);
}
if (rev_info_file != NULL)
fclose(rev_info_file);
if (error != 0)
{
fprintf(stderr, "Cannot write generic header\n");
die(SAMSUNG_WRITE_ERROR);
}
/* read metadata */
for (int i = 0; i < YPR0_COMPONENTS_COUNT; i++)
{
char metadata[MAX_HEADER_LEN];
error += fgets(metadata, MAX_HEADER_LEN, input_file) == NULL;
error += sscanf(metadata, "%*s : size(%ld),checksum(%s)",
&fw.component_size[i], fw.component_checksum[i]) != 2;
/* strip last ")" */
fw.component_checksum[i][strlen(fw.component_checksum[i])-1] = '\0';
printf("%s: %ld bytes -- MD5 %s\n", firmware_components[i],
fw.component_size[i], fw.component_checksum[i]);
}
/* We start from the end because ROM header could have a different
* line count or extra new-lines (noticed in some hacked ROMs)
*/
size_t current_pos = get_filesize(input_file);
for (int i = YPR0_COMPONENTS_COUNT-1; i >= 0; i--)
{
fw.component_data[i] = malloc(fw.component_size[i]);
current_pos -= fw.component_size[i];
fseek(input_file, current_pos, SEEK_SET);
size_t bread = fread(fw.component_data[i], 1, fw.component_size[i], input_file);
if (bread != fw.component_size[i])
fprintf(stderr, "%s: Read size mismatch: read %ld bytes, expected %ld bytes\n",
firmware_components[i], bread, fw.component_size[i]);
/* decrypt data */
cyclic_xor(fw.component_data[i], fw.component_size[i], g_yp_key, sizeof(g_yp_key));
/* unpatch bootloader */
if (strcmp("MBoot", firmware_components[i]) == 0)
{
memset(fw.component_data[i] + MBOOT_CHECKSUM_OFFSET, 0, MBOOT_CHECKSUM_LENGTH);
}
char md5sum_decrypted[MD5_DIGEST_LENGTH*2+1];
md5sum(md5sum_decrypted, fw.component_data[i], fw.component_size[i]);
if (strcmp(md5sum_decrypted, fw.component_checksum[i]) != 0)
{
printf("%s: FAIL (md5sum doesn't match)\n", firmware_components[i]);
md5sum_error = true;
}
join_path(tmp_path, output_dir, firmware_filenames[i]);
component_handle = fopen(tmp_path, "wb");
if (component_handle == NULL)
{
fprintf(stderr, "Error opening file for writing. Is the directory valid and writeable?\n");
die(SAMSUNG_WRITE_ERROR);
}
fwrite(fw.component_data[i], 1, fw.component_size[i], component_handle);
fclose(component_handle);
}
if (md5sum_error)
die(SAMSUNG_MD5_ERROR);
die(SAMSUNG_SUCCESS);
}
|
