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

uint32_t get_rand(uint8_t *out, uint32_t num_bytes)
{
	int rng = 50;
	int urnd = open("/dev/random", O_RDONLY);
	read(urnd, &rng, sizeof(int));
	*out = urnd;
	close(urnd);
	return 0;
}

double main(char *user_input, char *i )
{
    	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 */
	    char *ret_str = ciphertext;
    	uint16_t ciphertext_len;          /* no. of octets in ciphertext */
    	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 */
	    char *filename[33];
	    char **ptr = filename;
	    char buffer[557];
	    char *c;
	    char *f_name = "/tmp/cipher_EES401_";
	    char *f_ext = ".dat";
	    char *f_fin;
	    char f_spec[strlen(f_name)+strlen(f_ext)+5];
	    int r;
	    double cpu_time_used;
	    clock_t time_s, time_e;

	    FILE *f = fopen("EES401/EES401-ntru-pub.raw", "r");
	    r = fread(buffer, 1, 557, f);
	    fclose(f);

	    rc = ntru_crypto_drbg_external_instantiate(&get_rand, &drbg);
	    if (rc != DRBG_OK)
        {
            printf("Error 1\n");
	    	goto error;
        }
	    rc = ntru_crypto_ntru_encrypt(drbg, r, buffer, 32, user_input, &ciphertext_len,  NULL);
	    if (rc != DRBG_OK)
        {
            printf("Error 2\n");
	    	goto error;
        }
	    time_s = clock();
	    rc = ntru_crypto_ntru_encrypt(drbg, r, buffer, 32, user_input, &ciphertext_len,  ciphertext);

	    time_e = clock();
	    cpu_time_used = (float)(time_e - time_s) / CLOCKS_PER_SEC;
	    if (rc != DRBG_OK)
        {
            printf("Error 3\n");
	    	goto error;
        }

	    snprintf(f_spec, sizeof(f_spec), "%s%s%s", f_name, i, f_ext);
	    Handle=fopen(f_spec, "wb");
	    fwrite(ciphertext, sizeof(ciphertext), 1, Handle);
	    fclose(Handle);
	    return cpu_time_used;

    error: 
    	printf("ERROR %x\n", rc);
    	return 0;
}