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Diffstat (limited to 'utils/ypr0tools/fwdecrypt.c')
| -rw-r--r-- | utils/ypr0tools/fwdecrypt.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/utils/ypr0tools/fwdecrypt.c b/utils/ypr0tools/fwdecrypt.c new file mode 100644 index 0000000000..eb611feb37 --- /dev/null +++ b/utils/ypr0tools/fwdecrypt.c @@ -0,0 +1,168 @@ +/*************************************************************************** + * __________ __ ___. + * 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); +} |