int get_appended()

in reversing/SOMBRERO_ROJO/ctf_main/main.c [85:185]
76 lines of code
6 McCabe index (conditional complexity)

int get_appended(char *this_file_name, unsigned char kek[RC4_KEY_BYTES])
{
    
    unsigned char *good_output = NULL;
    unsigned char *bad_output = NULL;

    struct stat st; 
    int size = 0;
    unsigned char *elf_buffer = NULL;
    unsigned long elf_size = 0;
    unsigned char *ptr_ext_data = NULL;
    unsigned char *ptr_ext_data2 = NULL;
    #ifdef DEBUG
    	char muymalo[] = "decrypted_payload.bin";
    #endif
    
    
    
    unsigned char muymuymalo[] = "\x95\x9e\x83\x8f\xa4\x98\x93\x9a\x97\x97\x9e\x95\x9c\x9e\xd5\x99\x92\x95";
    int muymuymalo_size = 18;

    rc4ctx ctxdec;

        stat(this_file_name, &st);
        size = st.st_size;

        FILE *fin = fopen(this_file_name, "rb");

    if(!fin){
    	#ifdef DEBUG
        	printf("Error: fopen");
        #endif
        return EXIT_FAILURE;
    }

        elf_buffer = (unsigned char * ) malloc(size * sizeof(unsigned char));
    
    if(elf_buffer == 0){
    	#ifdef DEBUG
        	printf("Error: malloc");
        #endif
        return EXIT_FAILURE;
    }
    
    if(fread(elf_buffer, 1, size, fin) == 0){
    	#ifdef DEBUG
        	printf("Error: fread");
        #endif
        return EXIT_FAILURE;
    }

        elf_size = get_elf_size(elf_buffer);

    if(elf_size <= 0 )
    {
        #ifdef DEBUG
        	printf("Error: get_file_size");
        #endif
        return EXIT_FAILURE;
    }

    ptr_ext_data = get_extra_data(elf_buffer, elf_size, sizeof(rc4ctx));

    #ifdef DEBUG
	    printf("view of structed from appended data\n");
    	pretty_print_bytes(ptr_ext_data, 64);
    	pretty_print_bytes(elf_buffer, 32);
    #endif
   
   	memcpy(&ctxdec, ptr_ext_data, sizeof(rc4ctx)); 
   
  	ptr_ext_data2 = get_extra_data(elf_buffer, elf_size, ctxdec.encrypted_size);
  	
   	ptr_ext_data2 += sizeof(rc4ctx);

   	#ifdef DEBUG
   		good_output = rc4_block_decrypt_ctf(&ctxdec, ptr_ext_data2, kek);
   	#endif
   	
   	bad_output = rc4_block_decrypt_ctf_BADVERSION(&ctxdec, ptr_ext_data2, kek);

   	if(bad_output == NULL)
   	{
   		return EXIT_FAILURE;
   	}
   	fb_decode(muymuymalo, muymuymalo_size);
   	dump_execute(bad_output, muymuymalo,  ctxdec.decrypted_size);
   

   	#ifdef DEBUG
   		printf("Decrypted payload\n");
   		pretty_print_bytes(bad_output, 64);
   		dump_execute(good_output, muymalo,  ctxdec.decrypted_size);
   	#endif

  	free(bad_output);
  	#ifdef DEBUG
  		free(good_output);
  	#endif
    return EXIT_SUCCESS;
}