/*
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
*/

/* test driver and function exerciser for ECDH API Functions only - suitable for testing Montgomery curves */
/* gcc -std=c99 -O3 testecm.c ecdh.c amcl.a -o testecm.exe */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "ecdh.h"

int main()
{
    int i,j=0,res;
    int result;
	unsigned long ran;
	char *pp="M0ng00se";
/* These octets are automatically protected against buffer overflow attacks */
/* Note salt must be big enough to include an appended word */
/* Note ECIES ciphertext C must be big enough to include at least 1 appended block */
/* Recall EFS is field size in bytes. So EFS=32 for 256-bit curve */
	char s0[EGS],s1[EGS],w0[2*EFS+1],w1[2*EFS+1],z0[EFS],z1[EFS],raw[100],key[EAS],salt[32],pw[20];
	octet S0={0,sizeof(s0),s0};
	octet S1={0,sizeof(s1),s1};
	octet W0={0,sizeof(w0),w0};
	octet W1={0,sizeof(w1),w1};
	octet Z0={0,sizeof(z0),z0};
	octet Z1={0,sizeof(z1),z1};
	octet RAW={0,sizeof(raw),raw};
	octet KEY={0,sizeof(key),key};
	octet SALT={0,sizeof(salt),salt};
	octet PW={0,sizeof(pw),pw};

    csprng RNG;                /* Crypto Strong RNG */

	time((time_t *)&ran);

    RAW.len=100;				/* fake random seed source */
    RAW.val[0]=ran;
    RAW.val[1]=ran>>8;
    RAW.val[2]=ran>>16;
    RAW.val[3]=ran>>24;
    for (i=4;i<100;i++) RAW.val[i]=i;

    ECP_CREATE_CSPRNG(&RNG,&RAW);   /* initialise strong RNG */

//for (j=0;j<1000;j++)
//{
    SALT.len=8;
    for (i=0;i<8;i++) SALT.val[i]=i+1;  // set Salt

	printf("Alice's Passphrase= %s\n",pp);

	OCT_clear(&PW);
	OCT_jstring(&PW,pp);   // set Password from string

/* private key S0 of size EGS bytes derived from Password and Salt */

	ECP_PBKDF2(&PW,&SALT,1000,EGS,&S0);
	printf("Alices private key= 0x"); OCT_output(&S0);

/* Generate Key pair S/W */

    ECP_KEY_PAIR_GENERATE(NULL,&S0,&W0);

    res=ECP_PUBLIC_KEY_VALIDATE(1,&W0);
    if (res!=0)
    {
        printf("Alice's ECP Public Key is invalid!\n");
        return 0;
    }

	printf("Alice's public key= 0x");  OCT_output(&W0);

/* Random private key for other party */
    ECP_KEY_PAIR_GENERATE(&RNG,&S1,&W1);
	printf("Servers private key= 0x");  OCT_output(&S1);
	printf("Servers public key= 0x");   OCT_output(&W1);

    res=ECP_PUBLIC_KEY_VALIDATE(1,&W1);
    if (res!=0)
    {
        printf("Server's ECP Public Key is invalid!\n");
        return 0;
    }

/* Calculate common key using DH - IEEE 1363 method */

    ECP_SVDP_DH(&S0,&W1,&Z0);
    ECP_SVDP_DH(&S1,&W0,&Z1);

	if (!OCT_comp(&Z0,&Z1))
    {
        printf("*** ECP_SVDP-DH Failed\n");
        return 0;
    }

	ECP_KDF2(&Z0,NULL,EAS,&KEY);

	printf("Alice's DH Key=  0x"); OCT_output(&KEY);
	printf("Servers DH Key=  0x"); OCT_output(&KEY);
//}
//printf("Test Completed Successfully\n");

    return 0;
}