TV-box Arris VIP 4302 från Telia

// Telia Sucks! 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>

int decrypt_aes_ecb(const unsigned char *key, const char *input_filename, const char *output_filename, long offset) {
    AES_KEY aes_key;
    if (AES_set_decrypt_key(key, 256, &aes_key) != 0) {
        fprintf(stderr, "Failed to set decryption key\n");
        return -1;
    }

    FILE *input_file = fopen(input_filename, "rb");
    if (input_file == NULL) {
        fprintf(stderr, "Failed to open input file: %s\n", input_filename);
        return -1;
    }

    FILE *output_file = fopen(output_filename, "wb");
    if (output_file == NULL) {
        fprintf(stderr, "Failed to open output file: %s\n", output_filename);
        fclose(input_file);
        return -1;
    }

    fseek(input_file, offset, SEEK_SET);
    unsigned char in[16], out[16];
    size_t read_bytes;
    while ((read_bytes = fread(in, 1, sizeof(in), input_file)) > 0) {
        AES_decrypt(in, out, &aes_key);
        fwrite(out, 1, read_bytes, output_file);
    }

    fclose(input_file);
    fclose(output_file);
    return 0;
}

int main(int argc, char *argv[]) {
    if (argc < 4) {
        printf("Usage: %s <input file> <output file> <offset>\n", argv[0]);
        return -1;
    }

    const unsigned char key[] = {0x35, 0x24, 0x79, 0xec, 0xce, 0xf2, 0xf1, 0xe8, 
                                 0x58, 0x8e, 0x93, 0x5c, 0x26, 0xc3, 0xa1, 0x15,
                                 0x2b, 0x43, 0x3f, 0x86, 0xbd, 0x1e, 0xd3, 0x15, 
                                 0xcc, 0x1c, 0xed, 0x16, 0xc4, 0x67, 0x5c, 0xa2};

    const char *input_filename = argv[1];
    const char *output_filename = argv[2];
    long offset = strtol(argv[3], NULL, 0);

    if (decrypt_aes_ecb(key, input_filename, output_filename, offset) != 0) {
        fprintf(stderr, "Decryption failed\n");
        return -1;
    }

    printf("Decryption completed successfully.\n");
    return 0;
}