'use strict';
const common = require('../common');
const assert = require('assert');

if (!common.hasCrypto) {
  common.skip('missing crypto');
  return;
}
const crypto = require('crypto');
const DH_NOT_SUITABLE_GENERATOR = crypto.constants.DH_NOT_SUITABLE_GENERATOR;

// Test Diffie-Hellman with two parties sharing a secret,
// using various encodings as we go along
var dh1 = crypto.createDiffieHellman(common.hasFipsCrypto ? 1024 : 256);
var p1 = dh1.getPrime('buffer');
var dh2 = crypto.createDiffieHellman(p1, 'buffer');
var key1 = dh1.generateKeys();
var key2 = dh2.generateKeys('hex');
var secret1 = dh1.computeSecret(key2, 'hex', 'base64');
var secret2 = dh2.computeSecret(key1, 'latin1', 'buffer');

assert.equal(secret1, secret2.toString('base64'));
assert.equal(dh1.verifyError, 0);
assert.equal(dh2.verifyError, 0);

assert.throws(function() {
  crypto.createDiffieHellman([0x1, 0x2]);
});

assert.throws(function() {
  crypto.createDiffieHellman(function() { });
});

assert.throws(function() {
  crypto.createDiffieHellman(/abc/);
});

assert.throws(function() {
  crypto.createDiffieHellman({});
});

// Create "another dh1" using generated keys from dh1,
// and compute secret again
var dh3 = crypto.createDiffieHellman(p1, 'buffer');
var privkey1 = dh1.getPrivateKey();
dh3.setPublicKey(key1);
dh3.setPrivateKey(privkey1);

assert.deepStrictEqual(dh1.getPrime(), dh3.getPrime());
assert.deepStrictEqual(dh1.getGenerator(), dh3.getGenerator());
assert.deepStrictEqual(dh1.getPublicKey(), dh3.getPublicKey());
assert.deepStrictEqual(dh1.getPrivateKey(), dh3.getPrivateKey());
assert.equal(dh3.verifyError, 0);

var secret3 = dh3.computeSecret(key2, 'hex', 'base64');

assert.equal(secret1, secret3);

// Run this one twice to make sure that the dh3 clears its error properly
{
  const c = crypto.createDecipheriv('aes-128-ecb', crypto.randomBytes(16), '');
  assert.throws(function() { c.final('utf8'); }, /wrong final block length/);
}

assert.throws(function() {
  dh3.computeSecret('');
}, /key is too small/i);

{
  const c = crypto.createDecipheriv('aes-128-ecb', crypto.randomBytes(16), '');
  assert.throws(function() { c.final('utf8'); }, /wrong final block length/);
}

// Create a shared using a DH group.
var alice = crypto.createDiffieHellmanGroup('modp5');
var bob = crypto.createDiffieHellmanGroup('modp5');
alice.generateKeys();
bob.generateKeys();
var aSecret = alice.computeSecret(bob.getPublicKey()).toString('hex');
var bSecret = bob.computeSecret(alice.getPublicKey()).toString('hex');
assert.equal(aSecret, bSecret);
assert.equal(alice.verifyError, DH_NOT_SUITABLE_GENERATOR);
assert.equal(bob.verifyError, DH_NOT_SUITABLE_GENERATOR);

/* Ensure specific generator (buffer) works as expected.
 * The values below (modp2/modp2buf) are for a 1024 bits long prime from
 * RFC 2412 E.2, see https://tools.ietf.org/html/rfc2412. */
var modp2 = crypto.createDiffieHellmanGroup('modp2');
var modp2buf = Buffer.from([
  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc9, 0x0f,
  0xda, 0xa2, 0x21, 0x68, 0xc2, 0x34, 0xc4, 0xc6, 0x62, 0x8b,
  0x80, 0xdc, 0x1c, 0xd1, 0x29, 0x02, 0x4e, 0x08, 0x8a, 0x67,
  0xcc, 0x74, 0x02, 0x0b, 0xbe, 0xa6, 0x3b, 0x13, 0x9b, 0x22,
  0x51, 0x4a, 0x08, 0x79, 0x8e, 0x34, 0x04, 0xdd, 0xef, 0x95,
  0x19, 0xb3, 0xcd, 0x3a, 0x43, 0x1b, 0x30, 0x2b, 0x0a, 0x6d,
  0xf2, 0x5f, 0x14, 0x37, 0x4f, 0xe1, 0x35, 0x6d, 0x6d, 0x51,
  0xc2, 0x45, 0xe4, 0x85, 0xb5, 0x76, 0x62, 0x5e, 0x7e, 0xc6,
  0xf4, 0x4c, 0x42, 0xe9, 0xa6, 0x37, 0xed, 0x6b, 0x0b, 0xff,
  0x5c, 0xb6, 0xf4, 0x06, 0xb7, 0xed, 0xee, 0x38, 0x6b, 0xfb,
  0x5a, 0x89, 0x9f, 0xa5, 0xae, 0x9f, 0x24, 0x11, 0x7c, 0x4b,
  0x1f, 0xe6, 0x49, 0x28, 0x66, 0x51, 0xec, 0xe6, 0x53, 0x81,
  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
]);
var exmodp2 = crypto.createDiffieHellman(modp2buf, Buffer.from([2]));
modp2.generateKeys();
exmodp2.generateKeys();
var modp2Secret = modp2.computeSecret(exmodp2.getPublicKey()).toString('hex');
var exmodp2Secret = exmodp2.computeSecret(modp2.getPublicKey()).toString('hex');
assert.equal(modp2Secret, exmodp2Secret);
assert.equal(modp2.verifyError, DH_NOT_SUITABLE_GENERATOR);
assert.equal(exmodp2.verifyError, DH_NOT_SUITABLE_GENERATOR);


// Ensure specific generator (string with encoding) works as expected.
var exmodp2_2 = crypto.createDiffieHellman(modp2buf, '02', 'hex');
exmodp2_2.generateKeys();
modp2Secret = modp2.computeSecret(exmodp2_2.getPublicKey()).toString('hex');
var exmodp2_2Secret = exmodp2_2.computeSecret(modp2.getPublicKey())
                               .toString('hex');
assert.equal(modp2Secret, exmodp2_2Secret);
assert.equal(exmodp2_2.verifyError, DH_NOT_SUITABLE_GENERATOR);


// Ensure specific generator (string without encoding) works as expected.
var exmodp2_3 = crypto.createDiffieHellman(modp2buf, '\x02');
exmodp2_3.generateKeys();
modp2Secret = modp2.computeSecret(exmodp2_3.getPublicKey()).toString('hex');
var exmodp2_3Secret = exmodp2_3.computeSecret(modp2.getPublicKey())
                               .toString('hex');
assert.equal(modp2Secret, exmodp2_3Secret);
assert.equal(exmodp2_3.verifyError, DH_NOT_SUITABLE_GENERATOR);


// Ensure specific generator (numeric) works as expected.
var exmodp2_4 = crypto.createDiffieHellman(modp2buf, 2);
exmodp2_4.generateKeys();
modp2Secret = modp2.computeSecret(exmodp2_4.getPublicKey()).toString('hex');
var exmodp2_4Secret = exmodp2_4.computeSecret(modp2.getPublicKey())
                               .toString('hex');
assert.equal(modp2Secret, exmodp2_4Secret);
assert.equal(exmodp2_4.verifyError, DH_NOT_SUITABLE_GENERATOR);


var p = 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' +
        '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' +
        '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' +
        'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF';
var bad_dh = crypto.createDiffieHellman(p, 'hex');
assert.equal(bad_dh.verifyError, DH_NOT_SUITABLE_GENERATOR);


// Test ECDH
const ecdh1 = crypto.createECDH('prime256v1');
const ecdh2 = crypto.createECDH('prime256v1');
key1 = ecdh1.generateKeys();
key2 = ecdh2.generateKeys('hex');
secret1 = ecdh1.computeSecret(key2, 'hex', 'base64');
secret2 = ecdh2.computeSecret(key1, 'latin1', 'buffer');

assert.equal(secret1, secret2.toString('base64'));

// Oakley curves do not clean up ERR stack, it was causing unexpected failure
// when accessing other OpenSSL APIs afterwards.
crypto.createECDH('Oakley-EC2N-3');
crypto.createHash('sha256');

// Point formats
assert.equal(ecdh1.getPublicKey('buffer', 'uncompressed')[0], 4);
let firstByte = ecdh1.getPublicKey('buffer', 'compressed')[0];
assert(firstByte === 2 || firstByte === 3);
firstByte = ecdh1.getPublicKey('buffer', 'hybrid')[0];
assert(firstByte === 6 || firstByte === 7);

// ECDH should check that point is on curve
const ecdh3 = crypto.createECDH('secp256k1');
const key3 = ecdh3.generateKeys();

assert.throws(function() {
  ecdh2.computeSecret(key3, 'latin1', 'buffer');
});

// ECDH should allow .setPrivateKey()/.setPublicKey()
const ecdh4 = crypto.createECDH('prime256v1');

ecdh4.setPrivateKey(ecdh1.getPrivateKey());
ecdh4.setPublicKey(ecdh1.getPublicKey());

assert.throws(function() {
  ecdh4.setPublicKey(ecdh3.getPublicKey());
}, /Failed to convert Buffer to EC_POINT/);

// Verify that we can use ECDH without having to use newly generated keys.
const ecdh5 = crypto.createECDH('secp256k1');

// Verify errors are thrown when retrieving keys from an uninitialized object.
assert.throws(function() {
  ecdh5.getPublicKey();
}, /Failed to get ECDH public key/);
assert.throws(function() {
  ecdh5.getPrivateKey();
}, /Failed to get ECDH private key/);

// A valid private key for the secp256k1 curve.
const cafebabeKey = 'cafebabe'.repeat(8);
// Associated compressed and uncompressed public keys (points).
const cafebabePubPtComp =
'03672a31bfc59d3f04548ec9b7daeeba2f61814e8ccc40448045007f5479f693a3';
const cafebabePubPtUnComp =
'04672a31bfc59d3f04548ec9b7daeeba2f61814e8ccc40448045007f5479f693a3' +
'2e02c7f93d13dc2732b760ca377a5897b9dd41a1c1b29dc0442fdce6d0a04d1d';
ecdh5.setPrivateKey(cafebabeKey, 'hex');
assert.equal(ecdh5.getPrivateKey('hex'), cafebabeKey);
// Show that the public point (key) is generated while setting the private key.
assert.equal(ecdh5.getPublicKey('hex'), cafebabePubPtUnComp);

// Compressed and uncompressed public points/keys for other party's private key
// 0xDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEF
const peerPubPtComp =
'02c6b754b20826eb925e052ee2c25285b162b51fdca732bcf67e39d647fb6830ae';
const peerPubPtUnComp =
'04c6b754b20826eb925e052ee2c25285b162b51fdca732bcf67e39d647fb6830ae' +
'b651944a574a362082a77e3f2b5d9223eb54d7f2f76846522bf75f3bedb8178e';

const sharedSecret =
'1da220b5329bbe8bfd19ceef5a5898593f411a6f12ea40f2a8eead9a5cf59970';

assert.equal(ecdh5.computeSecret(peerPubPtComp, 'hex', 'hex'), sharedSecret);
assert.equal(ecdh5.computeSecret(peerPubPtUnComp, 'hex', 'hex'), sharedSecret);

// Verify that we still have the same key pair as before the computation.
assert.equal(ecdh5.getPrivateKey('hex'), cafebabeKey);
assert.equal(ecdh5.getPublicKey('hex'), cafebabePubPtUnComp);

// Verify setting and getting compressed and non-compressed serializations.
ecdh5.setPublicKey(cafebabePubPtComp, 'hex');
assert.equal(ecdh5.getPublicKey('hex'), cafebabePubPtUnComp);
assert.equal(ecdh5.getPublicKey('hex', 'compressed'), cafebabePubPtComp);
ecdh5.setPublicKey(cafebabePubPtUnComp, 'hex');
assert.equal(ecdh5.getPublicKey('hex'), cafebabePubPtUnComp);
assert.equal(ecdh5.getPublicKey('hex', 'compressed'), cafebabePubPtComp);

// Show why allowing the public key to be set on this type does not make sense.
ecdh5.setPublicKey(peerPubPtComp, 'hex');
assert.equal(ecdh5.getPublicKey('hex'), peerPubPtUnComp);
assert.throws(function() {
  // Error because the public key does not match the private key anymore.
  ecdh5.computeSecret(peerPubPtComp, 'hex', 'hex');
}, /Invalid key pair/);

// Set to a valid key to show that later attempts to set an invalid key are
// rejected.
ecdh5.setPrivateKey(cafebabeKey, 'hex');

[ // Some invalid private keys for the secp256k1 curve.
  '0000000000000000000000000000000000000000000000000000000000000000',
  'FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141',
  'FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF',
].forEach(function(element, index, object) {
  assert.throws(function() {
    ecdh5.setPrivateKey(element, 'hex');
  }, /Private key is not valid for specified curve/);
  // Verify object state did not change.
  assert.equal(ecdh5.getPrivateKey('hex'), cafebabeKey);
});