Add NSS function to retrieve TLS client cert types requested by server.

net/third_party/nss/ssl/sslimpl.h

 /*
  * This file is PRIVATE to SSL and should be the first thing included by
  * any SSL implementation file.
  *
  * ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
@@ skipping 1089 matching lines @@
     sslHandshakeFunc nextHandshake;                     /*firstHandshakeLock*/
     sslHandshakeFunc securityHandshake;                 /*firstHandshakeLock*/
 
     /* the following variable is only used with socks or other proxies. */
     char *           peerID;    /* String uniquely identifies target server. */
 
     unsigned char *  cipherSpecs;
     unsigned int     sizeCipherSpecs;
 const unsigned char *  preferredCipher;
 
+    /* TLS ClientCertificateTypes requested during HandleCertificateRequest. */
+    /* Will be NULL at all other times. */
+    const SECItem      *requestedCertTypes;
+
     ssl3KeyPair *         stepDownKeyPair;      /* RSA step down keys */
 
     /* Callbacks */
     SSLAuthCertificate        authCertificate;
     void                     *authCertificateArg;
     SSLGetClientAuthData      getClientAuthData;
     void                     *getClientAuthDataArg;
 #ifdef NSS_PLATFORM_CLIENT_AUTH
     SSLGetPlatformClientAuthData getPlatformClientAuthData;
     void                        *getPlatformClientAuthDataArg;
@@ skipping 627 matching lines @@
 #elif defined(_WIN32_WCE)
 #define SSL_GETPID GetCurrentProcessId
 #elif defined(WIN32)
 extern int __cdecl _getpid(void);
 #define SSL_GETPID _getpid
 #else
 #define SSL_GETPID() 0
 #endif
 
 #endif /* __sslimpl_h_ */