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

int main (void) {

EVP_CIPHER_CTX *ctx; //creates a new cipher context
char plaintext[] = "This is a top secret.";
unsigned char ciphertext[] = "\x8d\x20\xe5\x05\x6a\x8d\x24\xd0\x46\x2c\xe7\x4e\x49\x04\xc1\xb5\x13\xe1\x0d\x1d\xf4\xa2\xef\x2a\xd4\x54\x0f\xae\x1c\xa0\xaa\xf9";
unsigned char iv[16] = "\x0";
unsigned char outbuf[1024];
int outlen, tmplen;


//Import dictionary list
FILE *dictionary;
char line[20];
size_t len = 0;
ssize_t read;
dictionary = fopen("words.txt", "r");

if(dictionary == NULL)
{
	printf("Error reading dictionary file!");
	exit(1);
}

//sets up cipher context

while(fgets(line, 20, dictionary) != NULL)
{
	ctx = EVP_CIPHER_CTX_new();

	while(strlen(line) < 16)
	{
		strtok(line, "\n");
		strcat(line, " ");
	}
	EVP_EncryptInit_ex(ctx, EVP_aes_128_cbc(), NULL, line, iv);

	if(!EVP_EncryptUpdate(ctx, outbuf, &outlen, plaintext, strlen(plaintext)))
	{
		printf("Encrypt Update Error");
		exit(1);
	}
	/* Buffer passed to EVP_EncryptFinal() must be after data just
         * encrypted to avoid overwriting it.
         */
	if(!EVP_EncryptFinal_ex(ctx, outbuf + outlen, &tmplen))
	{
		printf("Encrypt Final Error");
		exit(1);
	}
	outlen += tmplen;

        EVP_CIPHER_CTX_free(ctx);

	//compare cipertexts
	if(memcmp(outbuf, ciphertext, outlen) == 0)
	{
		printf("%s", line);
	}
}

//Close dictionary file
fclose(dictionary);

return 0;
}