tls: revert default max to TLSv1.2

TLSv1.3 is still supported when explicitly configured, but it is not the
default.

PR-URL: nodejs#26951
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>

doc/api/tls.md

@@ -1351,7 +1351,7 @@ changes:
   * `maxVersion` {string} Optionally set the maximum TLS version to allow. One
     of `TLSv1.3`, `TLSv1.2'`, `'TLSv1.1'`, or `'TLSv1'`. Cannot be specified
     along with the `secureProtocol` option, use one or the other.
-    **Default:** `'TLSv1.3'`, unless changed using CLI options. Using
+    **Default:** `'TLSv1.2'`, unless changed using CLI options. Using
     `--tls-max-v1.2` sets the default to `'TLSv1.2`'. Using `--tls-max-v1.3`
     sets the default to `'TLSv1.3'`. If multiple of the options are provided,
     the highest maximum is used.
@@ -1360,7 +1360,7 @@ changes:
     along with the `secureProtocol` option, use one or the other. It is not
     recommended to use less than TLSv1.2, but it may be required for
     interoperability.
-    **Default:** `'TLSv1.2'`, unless changed using CLI options. Using
+    **Default:** `'TLSv1'`, unless changed using CLI options. Using
     `--tls-min-v1.0` sets the default to `'TLSv1'`. Using `--tls-min-v1.1` sets
     the default to `'TLSv1.1'`. Using `--tls-min-v1.3` sets the default to
     `'TLSv1.3'`. If multiple of the options are provided, the lowest minimum is

lib/tls.js

@@ -54,8 +54,6 @@ exports.DEFAULT_CIPHERS =
 
 exports.DEFAULT_ECDH_CURVE = 'auto';
 
-exports.DEFAULT_MAX_VERSION = 'TLSv1.3';
-
 if (getOptionValue('--tls-min-v1.0'))
   exports.DEFAULT_MIN_VERSION = 'TLSv1';
 else if (getOptionValue('--tls-min-v1.1'))
@@ -70,7 +68,7 @@ if (getOptionValue('--tls-max-v1.3'))
 else if (getOptionValue('--tls-max-v1.2'))
   exports.DEFAULT_MAX_VERSION = 'TLSv1.2';
 else
-  exports.DEFAULT_MAX_VERSION = 'TLSv1.3'; // Will depend on node version.
+  exports.DEFAULT_MAX_VERSION = 'TLSv1.2'; // Will depend on node version.
 
 
 exports.getCiphers = internalUtil.cachedResult(

src/node_options.cc

@@ -341,15 +341,15 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
             &EnvironmentOptions::tls_min_v1_3,
             kAllowedInEnvironment);
   AddOption("--tls-max-v1.2",
-            "set default TLS maximum to TLSv1.2 (default: TLSv1.3)",
+            "set default TLS maximum to TLSv1.2 (default: TLSv1.2)",
             &EnvironmentOptions::tls_max_v1_2,
             kAllowedInEnvironment);
   // Current plan is:
   // - 11.x and below: TLS1.3 is opt-in with --tls-max-v1.3
   // - 12.x: TLS1.3 is opt-out with --tls-max-v1.2
   // In either case, support both options they are uniformly available.
   AddOption("--tls-max-v1.3",
-            "set default TLS maximum to TLSv1.3 (default: TLSv1.3)",
+            "set default TLS maximum to TLSv1.3 (default: TLSv1.2)",
             &EnvironmentOptions::tls_max_v1_3,
             kAllowedInEnvironment);
 }

test/parallel/test-tls-cli-min-version-1.0.js

@@ -8,7 +8,7 @@ if (!common.hasCrypto) common.skip('missing crypto');
 const assert = require('assert');
 const tls = require('tls');
 
-assert.strictEqual(tls.DEFAULT_MAX_VERSION, 'TLSv1.3');
+assert.strictEqual(tls.DEFAULT_MAX_VERSION, 'TLSv1.2');
 assert.strictEqual(tls.DEFAULT_MIN_VERSION, 'TLSv1');
 
 // Check the min-max version protocol versions against these CLI settings.

test/parallel/test-tls-cli-min-version-1.1.js

@@ -8,7 +8,7 @@ if (!common.hasCrypto) common.skip('missing crypto');
 const assert = require('assert');
 const tls = require('tls');
 
-assert.strictEqual(tls.DEFAULT_MAX_VERSION, 'TLSv1.3');
+assert.strictEqual(tls.DEFAULT_MAX_VERSION, 'TLSv1.2');
 assert.strictEqual(tls.DEFAULT_MIN_VERSION, 'TLSv1.1');
 
 // Check the min-max version protocol versions against these CLI settings.

test/parallel/test-tls-cli-min-version-1.3.js

@@ -8,7 +8,7 @@ if (!common.hasCrypto) common.skip('missing crypto');
 const assert = require('assert');
 const tls = require('tls');
 
-assert.strictEqual(tls.DEFAULT_MAX_VERSION, 'TLSv1.3');
+assert.strictEqual(tls.DEFAULT_MAX_VERSION, 'TLSv1.2');
 assert.strictEqual(tls.DEFAULT_MIN_VERSION, 'TLSv1.3');
 
 // Check the min-max version protocol versions against these CLI settings.

test/parallel/test-tls-client-renegotiation-13.js

@@ -1,3 +1,4 @@
+// Flags: --tls-max-v1.3
 'use strict';
 
 const common = require('../common');

test/parallel/test-tls-min-max-version.js

@@ -68,8 +68,13 @@ function test(cmin, cmax, cprot, smin, smax, sprot, proto, cerr, serr) {
 
 const U = undefined;
 
-// Default protocol is the max version.
-test(U, U, U, U, U, U, DEFAULT_MAX_VERSION);
+if (DEFAULT_MAX_VERSION === 'TLSv1.2' && DEFAULT_MIN_VERSION === 'TLSv1.3') {
+  // No connections are possible by default.
+  test(U, U, U, U, U, U, U, 'ERR_SSL_NO_PROTOCOLS_AVAILABLE', U);
+} else {
+  // Default protocol is the max version.
+  test(U, U, U, U, U, U, DEFAULT_MAX_VERSION);
+}
 
 // Insecure or invalid protocols cannot be enabled.
 test(U, U, U, U, U, 'SSLv2_method',

test/parallel/test-tls-set-ciphers.js

@@ -6,9 +6,13 @@ const fixtures = require('../common/fixtures');
 // Test cipher: option for TLS.
 
 const {
-  assert, connect, keys
+  assert, connect, keys, tls
 } = require(fixtures.path('tls-connect'));
 
+const tls13 = !!require('constants').TLS1_3_VERSION;
+
+if (tls13)
+  tls.DEFAULT_MAX_VERSION = 'TLSv1.3';
 
 function test(cciphers, sciphers, cipher, cerr, serr) {
   assert(cipher || cerr || serr, 'test missing any expectations');