crypto: remove ALPN_ENABLED

This constant was likely introduced for feature detection, but it has been pointless for a long time. 1. I am not aware of any possible Node.js build configuration (on any recent/supported release line) that would have crypto.constants but not crypto.constants.ALPN_ENABLED. 2. There is no evidence of this constant being used for feature detection in the ecosystem. In fact, both internal and external type definitions for crypto.constants simply assume that the constant exists. 3. There is no good reason for any modern TLS stack to not support ALPN. It looks like ALPN might have been optional in much earlier versions of OpenSSL, but all recent versions of OpenSSL unconditionally support ALPN as far as I can tell. Refs: #46956 PR-URL: #47028 Reviewed-By: Filip Skokan <panva.ip@gmail.com> Reviewed-By: Rich Trott <rtrott@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

Author: tniessen

doc/api/crypto.md

@@ -5980,10 +5980,6 @@ See the [list of SSL OP Flags][] for details.
  <td><code>DH_NOT_SUITABLE_GENERATOR</code></td>
  <td></td>
  </tr>
- <tr>
- <td><code>ALPN_ENABLED</code></td>
- <td></td>
- </tr>
  <tr>
  <td><code>RSA_PKCS1_PADDING</code></td>
  <td></td>

src/node_constants.cc

@@ -1032,9 +1032,6 @@ void DefineCryptoConstants(Local<Object> target) {
  NODE_DEFINE_CONSTANT(target, DH_NOT_SUITABLE_GENERATOR);
 #endif
 
-#define ALPN_ENABLED 1
- NODE_DEFINE_CONSTANT(target, ALPN_ENABLED);
-
 #ifdef RSA_PKCS1_PADDING
  NODE_DEFINE_CONSTANT(target, RSA_PKCS1_PADDING);
 #endif

typings/internalBinding/constants.d.ts

@@ -243,7 +243,6 @@ declare function InternalBinding(binding: 'constants'): {
  DH_CHECK_P_NOT_PRIME: 1;
  DH_UNABLE_TO_CHECK_GENERATOR: 4;
  DH_NOT_SUITABLE_GENERATOR: 8;
- ALPN_ENABLED: 1;
  RSA_PKCS1_PADDING: 1;
  RSA_SSLV23_PADDING: 2;
  RSA_NO_PADDING: 3;