tls: support OCSP on client and server

doc/api/tls.markdown

@@ -408,6 +408,10 @@ Construct a new TLSSocket object from existing TCP socket.
 
   - `session`: Optional, a `Buffer` instance, containing TLS session
 
+  - `requestOCSP`: Optional, if `true` - OCSP status request extension would
+    be added to client hello, and `OCSPResponse` event will be emitted on socket
+    before establishing secure communication
+
 ## tls.createSecurePair([context], [isServer], [requestCert], [rejectUnauthorized])
 
     Stability: 0 - Deprecated. Use tls.TLSSocket instead.
@@ -508,6 +512,44 @@ NOTE: adding this event listener will have an effect only on connections
 established after addition of event listener.
 
 
+### Event: 'OCSPRequest'
+
+`function (certificate, issuer, callback) { }`
+
+Emitted when the client sends a certificate status request. You could parse
+server's current certificate to obtain OCSP url and certificate id, and after
+obtaining OCSP response invoke `callback(null, resp)`, where `resp` is a
+`Buffer` instance. Both `certificate` and `issuer` are a `Buffer`
+DER-representations of the primary and issuer's certificates. They could be used
+to obtain OCSP certificate id and OCSP endpoint url.
+
+Alternatively, `callback(null, null)` could be called, meaning that there is no
+OCSP response.
+
+Calling `callback(err)` will result in a `socket.destroy(err)` call.
+
+Typical flow:
+
+1. Client connects to server and sends `OCSPRequest` to it (via status info
+   extension in ClientHello.)
+2. Server receives request and invokes `OCSPRequest` event listener if present
+3. Server grabs OCSP url from either `certificate` or `issuer` and performs an
+   [OCSP request] to the CA
+4. Server receives `OCSPResponse` from CA and sends it back to client via
+   `callback` argument
+5. Client validates the response and either destroys socket or performs a
+   handshake.
+
+NOTE: `issuer` could be null, if certficiate is self-signed or if issuer is not
+in the root certificates list. (You could provide an issuer via `ca` option.)
+
+NOTE: adding this event listener will have an effect only on connections
+established after addition of event listener.
+
+NOTE: you may want to use some npm module like [asn1.js] to parse the
+certificates.
+
+
 ### server.listen(port, [host], [callback])
 
 Begin accepting connections on the specified `port` and `host`.  If the
@@ -577,6 +619,16 @@ If `tlsSocket.authorized === false` then the error can be found in
 `tlsSocket.authorizationError`. Also if NPN was used - you can check
 `tlsSocket.npnProtocol` for negotiated protocol.
 
+### Event: 'OCSPResponse'
+
+`function (response) { }`
+
+This event will be emitted if `requestOCSP` option was set. `response` is a
+buffer object, containing server's OCSP response.
+
+Traditionally, the `response` is a signed object from the server's CA that
+contains information about server's certificate revocation status.
+
 ### tlsSocket.encrypted
 
 Static boolean value, always `true`. May be used to distinguish TLS sockets
@@ -711,3 +763,5 @@ The numeric representation of the local port.
 [Forward secrecy]: http://en.wikipedia.org/wiki/Perfect_forward_secrecy
 [DHE]: https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange
 [ECDHE]: https://en.wikipedia.org/wiki/Elliptic_curve_Diffie%E2%80%93Hellman
+[asn1.js]: http://npmjs.org/package/asn1.js
+[OCSP request]: http://en.wikipedia.org/wiki/OCSP_stapling

lib/_tls_common.js

@@ -68,18 +68,8 @@ exports.createSecureContext = function createSecureContext(options, context) {
     }
   }
 
-  if (options.cert) c.context.setCert(options.cert);
-
-  if (options.ciphers)
-    c.context.setCiphers(options.ciphers);
-  else
-    c.context.setCiphers(tls.DEFAULT_CIPHERS);
-
-  if (util.isUndefined(options.ecdhCurve))
-    c.context.setECDHCurve(tls.DEFAULT_ECDH_CURVE);
-  else if (options.ecdhCurve)
-    c.context.setECDHCurve(options.ecdhCurve);
-
+  // NOTE: It's important to add CA before the cert to be able to load
+  // cert's issuer in C++ code.
   if (options.ca) {
     if (util.isArray(options.ca)) {
       for (var i = 0, len = options.ca.length; i < len; i++) {
@@ -92,6 +82,18 @@ exports.createSecureContext = function createSecureContext(options, context) {
     c.context.addRootCerts();
   }
 
+  if (options.cert) c.context.setCert(options.cert);
+
+  if (options.ciphers)
+    c.context.setCiphers(options.ciphers);
+  else
+    c.context.setCiphers(tls.DEFAULT_CIPHERS);
+
+  if (util.isUndefined(options.ecdhCurve))
+    c.context.setECDHCurve(tls.DEFAULT_ECDH_CURVE);
+  else if (options.ecdhCurve)
+    c.context.setECDHCurve(options.ecdhCurve);
+
   if (options.crl) {
     if (util.isArray(options.crl)) {
       for (var i = 0, len = options.crl.length; i < len; i++) {
@@ -126,3 +128,27 @@ exports.createSecureContext = function createSecureContext(options, context) {
 
   return c;
 };
+
+exports.translatePeerCertificate = function translatePeerCertificate(c) {
+  if (!c)
+    return null;
+
+  if (c.issuer) c.issuer = tls.parseCertString(c.issuer);
+  if (c.subject) c.subject = tls.parseCertString(c.subject);
+  if (c.infoAccess) {
+    var info = c.infoAccess;
+    c.infoAccess = {};
+
+    // XXX: More key validation?
+    info.replace(/([^\n:]*):([^\n]*)(?:\n|$)/g, function(all, key, val) {
+      if (key === '__proto__')
+        return;
+
+      if (c.infoAccess.hasOwnProperty(key))
+        c.infoAccess[key].push(val);
+      else
+        c.infoAccess[key] = [val];
+    });
+  }
+  return c;
+};

lib/_tls_legacy.js

@@ -25,6 +25,7 @@ var events = require('events');
 var stream = require('stream');
 var tls = require('tls');
 var util = require('util');
+var common = require('_tls_common');
 
 var Timer = process.binding('timer_wrap').Timer;
 var Connection = null;
@@ -378,15 +379,8 @@ CryptoStream.prototype.__defineGetter__('bytesWritten', function() {
 });
 
 CryptoStream.prototype.getPeerCertificate = function() {
-  if (this.pair.ssl) {
-    var c = this.pair.ssl.getPeerCertificate();
-
-    if (c) {
-      if (c.issuer) c.issuer = tls.parseCertString(c.issuer);
-      if (c.subject) c.subject = tls.parseCertString(c.subject);
-      return c;
-    }
-  }
+  if (this.pair.ssl)
+    return common.translatePeerCertificate(this.pair.ssl.getPeerCertificate());
 
   return null;
 };
@@ -677,6 +671,11 @@ function onnewsessiondone() {
 }
 
 
+function onocspresponse(resp) {
+  this.emit('OCSPResponse', resp);
+}
+
+
 /**
  * Provides a pair of streams to do encrypted communication.
  */
@@ -733,6 +732,8 @@ function SecurePair(context, isServer, requestCert, rejectUnauthorized,
     this.ssl.onnewsession = onnewsession.bind(this);
     this.ssl.lastHandshakeTime = 0;
     this.ssl.handshakes = 0;
+  } else {
+    this.ssl.onocspresponse = onocspresponse.bind(this);
   }
 
   if (process.features.tls_sni) {
@@ -764,6 +765,9 @@ function SecurePair(context, isServer, requestCert, rejectUnauthorized,
     if (self.ssl) {
       self.ssl.start();
 
+      if (options.requestOCSP)
+        self.ssl.requestOCSP();
+
       /* In case of cipher suite failures - SSL_accept/SSL_connect may fail */
       if (self.ssl && self.ssl.error)
         self.error();