#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include "ntru_crypto.h"

//typedef uint32_t (*urnd)(uint8_t *out, uint32_t num_bytes);
//static uint8_t const aes_key[] = "Decrypt me, WTF";
uint32_t get_rand(uint8_t *out, uint32_t num_bytes)
{
	int rng = 112 ;
	int urnd = open("/dev/random", O_RDONLY);
	read(urnd, &rng, sizeof(int));
	*out = urnd;
	close(urnd);
	return 0;
}

int main(void) {


	//uint8_t public_key[557];
    	uint8_t public_key[557];          /* sized for EES401EP2 */
    	uint16_t public_key_len;          /* no. of octets in public key */
    	uint8_t private_key[607];         /* sized for EES401EP2 */
    	uint16_t private_key_len;         /* no. of octets in private key */
    	uint16_t expected_private_key_len;
    	uint16_t expected_encoded_public_key_len;
    	uint8_t encoded_public_key[593];  /* sized for EES401EP2 */
    	uint16_t encoded_public_key_len;  /* no. of octets in encoded public key */
    	uint8_t ciphertext[552];          /* sized fof EES401EP2 */
    	uint16_t ciphertext_len;          /* no. of octets in ciphertext */
    	uint8_t plaintext[16];            /* size of AES-128 key */
    	uint16_t plaintext_len;           /* no. of octets in plaintext */
    	uint8_t *next = NULL;             /* points to next cert field to parse */
    	uint32_t next_len;                /* no. of octets it next */
    	DRBG_HANDLE drbg;                 /* handle for instantiated DRBG */
    	uint32_t rc;                      /* return code */
    	bool error = FALSE;               /* records if error occurred */
    	FILE *Handle=NULL;                /* File Handle for writing NTRU key to file */

	rc = ntru_crypto_drbg_external_instantiate(&get_rand, &drbg);

	if (rc != DRBG_OK)
		goto error;

	rc = ntru_crypto_ntru_encrypt_keygen(drbg, NTRU_EES401EP2, &public_key_len, NULL, &private_key_len, NULL);

	if (rc != NTRU_OK)
	{
		error = TRUE;
	}
	expected_private_key_len=private_key_len;
	rc = ntru_crypto_ntru_encrypt_keygen(drbg, NTRU_EES401EP2, &public_key_len, public_key, &private_key_len, private_key);

	if (rc != NTRU_OK)
		error = TRUE;

	if (expected_private_key_len!=private_key_len)
	{
		fprintf(stderr, "PRivate key length is different\n");
		error  = TRUE;
	}

	printf("Key sucessfully generated. \n");

	rc = ntru_crypto_drbg_uninstantiate(drbg);
	if ((rc != DRBG_OK) || error)
	{
		error = TRUE;
	}

	printf("KEY DRBG Success. \n");

	Handle=fopen("Nino-ntru-key.raw","wb");
	if (Handle!=NULL){
		printf("Writing Pirvatkey\n");
		fwrite(private_key, private_key_len, 1, Handle);
		fclose(Handle);
	}
	Handle=fopen("Nino-ntru-pubkey.raw","wb");
	if(Handle!=NULL){
		printf("Writing Publickey\n");
		fwrite(public_key, public_key_len, 1, Handle);
		fclose(Handle);
	}

	rc = ntru_crypto_ntru_encrypt_publicKey2SubjectPublicKeyInfo(public_key_len, public_key, &encoded_public_key_len, NULL);
	if (rc != NTRU_OK)
		goto error;
	printf("DER encoded, sized requierd %d . \n", encoded_public_ket_len);
	expected_encoded_public_key_len = encoded_public_key_len;
	rc = ntru_crypto_ntru_encrypt_publicKey2SubjectPublicKeyInfo(public_key_len, public_key, &encoded_public_key_len, encoded_public_key);

	if (expected_encoded_public_key_len!=encoded_public_key_len)
	{
		fprintf(stderr, "Different encoded pub key detected\n");
		error = TRUE;
	}

	printf("Pub DER Encoding success\n");

	rc = ntru_crypto_ntru_encrypt(dbrg, public_key_len, public_key, sizeof(aes_key), aes_key, &ciphertext_len, ciphertext);
	
	printf("%s\n", ciphertext);
	printf("Done BLyat!!!!\n");
	
error:
	printf("ERROR %x\n", rc);
	return 1;
	
}