test-tls-client-mindhsize.js

// Flags: --expose-internals
'use strict';
const common = require('../common');
if (!common.hasCrypto)
  common.skip('missing crypto');

// OpenSSL has a set of security levels which affect what algorithms
// are available by default. Different OpenSSL veresions have different
// default security levels and we use this value to adjust what a test
// expects based on the security level. You can read more in
// https://docs.openssl.org/1.1.1/man3/SSL_CTX_set_security_level/#default-callback-behaviour
const secLevel = require('internal/crypto/util').getOpenSSLSecLevel();
const assert = require('assert');
const tls = require('tls');
const fixtures = require('../common/fixtures');
const { hasOpenSSL } = require('../common/crypto');

const key = fixtures.readKey('agent2-key.pem');
const cert = fixtures.readKey('agent2-cert.pem');

let nsuccess = 0;
let nerror = 0;

function loadDHParam(n) {
  return fixtures.readKey(`dh${n}.pem`);
}

function test(size, err, next, minDHSizeOverride) {
  const options = {
    key: key,
    cert: cert,
    dhparam: loadDHParam(size),
    ciphers: 'DHE-RSA-AES128-GCM-SHA256'
  };

  const server = tls.createServer(options, function(conn) {
    conn.end();
  });

  server.on('close', common.mustCall(function(isException) {
    assert(!isException);
    if (next) next();
  }));

  server.listen(0, common.mustCall(function() {
    // Client set minimum DH parameter size to 2048 or 3072 bits
    // so that it fails when it makes a connection to the tls
    // server where is too small. This depends on the openssl
    // security level
    const minDHSize = minDHSizeOverride ?? ((secLevel > 1) ? 3072 : 2048);
    const client = tls.connect({
      minDHSize: minDHSize,
      port: this.address().port,
      rejectUnauthorized: false,
      maxVersion: 'TLSv1.2',
    }, function() {
      nsuccess++;
      server.close();
    });
    if (err) {
      client.on('error', common.mustCall((e) => {
        nerror++;
        assert.strictEqual(e.code, 'ERR_TLS_DH_PARAM_SIZE');
        server.close();
      }));
    }
  }));
}

// A client connection fails with an error when a client has an
// 2048 bits minDHSize option and a server has 1024 bits dhparam
function testDHE1024() {
  test(1024, true, testDHE2048(false, null));
}

// Test a client connection when a client has an
// 2048 bits minDHSize option
function testDHE2048(expect_to_fail, next) {
  test(2048, expect_to_fail, next);
}

// A client connection successes when a client has an
// 3072 bits minDHSize option and a server has 3072 bits dhparam
function testDHE3072() {
  test(3072, false, null);
}

if (hasOpenSSL(4, 0)) {
  // OpenSSL 4.0 implements RFC 7919 FFDHE negotiation for TLS 1.2 and
  // ignores the server-supplied dhparam in favor of FFDHE-2048. The 3072
  // success case is therefore replaced by a 2048 success case.
  testDHE2048(true, () => test(2048, false, null, 2048));
} else if (secLevel > 1) {
  // Minimum size for OpenSSL security level 2 and above is 2048 by default
  testDHE2048(true, testDHE3072);
} else {
  testDHE1024();
}

assert.throws(() => test(512, true, common.mustNotCall()),
              /DH parameter is less than 1024 bits/);

for (const minDHSize of [0, -1, -Infinity, NaN]) {
  assert.throws(() => {
    tls.connect({ minDHSize });
  }, {
    code: 'ERR_OUT_OF_RANGE',
    name: 'RangeError',
  });
}

for (const minDHSize of [true, false, null, undefined, {}, [], '', '1']) {
  assert.throws(() => {
    tls.connect({ minDHSize });
  }, {
    code: 'ERR_INVALID_ARG_TYPE',
    name: 'TypeError',
  });
}

process.on('exit', function() {
  assert.strictEqual(nsuccess, 1);
  assert.strictEqual(nerror, 1);
});