text: /*
   * $Id$
   * 'OpenSSL for Ruby' project
   * Copyright (C) 2000-2002  GOTOU Yuuzou <gotoyuzo@notwork.org>
   * Copyright (C) 2001-2002  Michal Rokos <m.rokos@sh.cvut.cz>
   * Copyright (C) 2001-2007  Technorama Ltd. <oss-ruby@technorama.net>
   * All rights reserved.
   */
  /*
   * This program is licensed under the same licence as Ruby.
   * (See the file 'LICENCE'.)
   */
  #include "ossl.h"
  
  #if defined(HAVE_UNISTD_H)
  #  include <unistd.h> /* for read(), and write() */
  #endif
  
  #define numberof(ary) (int)(sizeof(ary)/sizeof((ary)[0]))
  
  #ifdef _WIN32
  #  define TO_SOCKET(s) _get_osfhandle(s)
  #else
  #  define TO_SOCKET(s) (s)
  #endif
  
  #define GetSSLCTX(obj, ctx) do { \
  	TypedData_Get_Struct((obj), SSL_CTX, &ossl_sslctx_type, (ctx));	\
  } while (0)
  
  VALUE mSSL;
  VALUE eSSLError;
  VALUE cSSLContext;
  VALUE cSSLSocket;
  
  static VALUE eSSLErrorWaitReadable;
  static VALUE eSSLErrorWaitWritable;
  
  #define ossl_sslctx_set_cert(o,v)        	rb_iv_set((o),"@cert",(v))
  #define ossl_sslctx_set_key(o,v)         	rb_iv_set((o),"@key",(v))
  #define ossl_sslctx_set_client_ca(o,v)   	rb_iv_set((o),"@client_ca",(v))
  #define ossl_sslctx_set_ca_file(o,v)     	rb_iv_set((o),"@ca_file",(v))
  #define ossl_sslctx_set_ca_path(o,v)     	rb_iv_set((o),"@ca_path",(v))
  #define ossl_sslctx_set_timeout(o,v)     	rb_iv_set((o),"@timeout",(v))
  #define ossl_sslctx_set_verify_mode(o,v) 	rb_iv_set((o),"@verify_mode",(v))
  #define ossl_sslctx_set_verify_dep(o,v)  	rb_iv_set((o),"@verify_depth",(v))
  #define ossl_sslctx_set_verify_cb(o,v)   	rb_iv_set((o),"@verify_callback",(v))
  #define ossl_sslctx_set_options(o,v)     	rb_iv_set((o),"@options",(v))
  #define ossl_sslctx_set_cert_store(o,v)  	rb_iv_set((o),"@cert_store",(v))
  #define ossl_sslctx_set_extra_cert(o,v)  	rb_iv_set((o),"@extra_chain_cert",(v))
  #define ossl_sslctx_set_client_cert_cb(o,v) 	rb_iv_set((o),"@client_cert_cb",(v))
  #define ossl_sslctx_set_tmp_dh_cb(o,v)   	rb_iv_set((o),"@tmp_dh_callback",(v))
  #define ossl_sslctx_set_sess_id_ctx(o, v) 	rb_iv_set((o),"@session_id_context",(v))
  
  #define ossl_sslctx_get_cert(o)          	rb_iv_get((o),"@cert")
  #define ossl_sslctx_get_key(o)           	rb_iv_get((o),"@key")
  #define ossl_sslctx_get_client_ca(o)     	rb_iv_get((o),"@client_ca")
  #define ossl_sslctx_get_ca_file(o)       	rb_iv_get((o),"@ca_file")
  #define ossl_sslctx_get_ca_path(o)       	rb_iv_get((o),"@ca_path")
  #define ossl_sslctx_get_timeout(o)       	rb_iv_get((o),"@timeout")
  #define ossl_sslctx_get_verify_mode(o)   	rb_iv_get((o),"@verify_mode")
  #define ossl_sslctx_get_verify_dep(o)    	rb_iv_get((o),"@verify_depth")
  #define ossl_sslctx_get_verify_cb(o)     	rb_iv_get((o),"@verify_callback")
  #define ossl_sslctx_get_options(o)       	rb_iv_get((o),"@options")
  #define ossl_sslctx_get_cert_store(o)    	rb_iv_get((o),"@cert_store")
  #define ossl_sslctx_get_extra_cert(o)    	rb_iv_get((o),"@extra_chain_cert")
  #define ossl_sslctx_get_client_cert_cb(o) 	rb_iv_get((o),"@client_cert_cb")
  #define ossl_sslctx_get_tmp_dh_cb(o)     	rb_iv_get((o),"@tmp_dh_callback")
  #define ossl_sslctx_get_sess_id_ctx(o)   	rb_iv_get((o),"@session_id_context")
  
  static const char *ossl_sslctx_attrs[] = {
      "cert", "key", "client_ca", "ca_file", "ca_path",
      "timeout", "verify_mode", "verify_depth", "renegotiation_cb",
      "verify_callback", "options", "cert_store", "extra_chain_cert",
      "client_cert_cb", "tmp_dh_callback", "session_id_context",
      "session_get_cb", "session_new_cb", "session_remove_cb",
  #ifdef HAVE_SSL_SET_TLSEXT_HOST_NAME
      "servername_cb",
  #endif
  #ifdef HAVE_OPENSSL_NPN_NEGOTIATED
      "npn_protocols",
      "npn_select_cb",
  #endif
  };
  
  #define ossl_ssl_get_io(o)           rb_iv_get((o),"@io")
  #define ossl_ssl_get_ctx(o)          rb_iv_get((o),"@context")
  #define ossl_ssl_get_sync_close(o)   rb_iv_get((o),"@sync_close")
  #define ossl_ssl_get_x509(o)         rb_iv_get((o),"@x509")
  #define ossl_ssl_get_key(o)          rb_iv_get((o),"@key")
  #define ossl_ssl_get_tmp_dh(o)       rb_iv_get((o),"@tmp_dh")
  
  #define ossl_ssl_set_io(o,v)         rb_iv_set((o),"@io",(v))
  #define ossl_ssl_set_ctx(o,v)        rb_iv_set((o),"@context",(v))
  #define ossl_ssl_set_sync_close(o,v) rb_iv_set((o),"@sync_close",(v))
  #define ossl_ssl_set_x509(o,v)       rb_iv_set((o),"@x509",(v))
  #define ossl_ssl_set_key(o,v)        rb_iv_set((o),"@key",(v))
  #define ossl_ssl_set_tmp_dh(o,v)     rb_iv_set((o),"@tmp_dh",(v))
  
  static const char *ossl_ssl_attr_readers[] = { "io", "context", };
  static const char *ossl_ssl_attrs[] = {
  #ifdef HAVE_SSL_SET_TLSEXT_HOST_NAME
      "hostname",
  #endif
      "sync_close",
  };
  
  ID ID_callback_state;
  
  static VALUE sym_exception, sym_wait_readable, sym_wait_writable;
  
  /*
   * SSLContext class
   */
  static const struct {
      const char *name;
      SSL_METHOD *(*func)(void);
  } ossl_ssl_method_tab[] = {
  #define OSSL_SSL_METHOD_ENTRY(name) { #name, (SSL_METHOD *(*)(void))name##_method }
      OSSL_SSL_METHOD_ENTRY(TLSv1),
      OSSL_SSL_METHOD_ENTRY(TLSv1_server),
      OSSL_SSL_METHOD_ENTRY(TLSv1_client),
  #if defined(HAVE_TLSV1_2_METHOD) && defined(HAVE_TLSV1_2_SERVER_METHOD) && \
          defined(HAVE_TLSV1_2_CLIENT_METHOD)
      OSSL_SSL_METHOD_ENTRY(TLSv1_2),
      OSSL_SSL_METHOD_ENTRY(TLSv1_2_server),
      OSSL_SSL_METHOD_ENTRY(TLSv1_2_client),
  #endif
  #if defined(HAVE_TLSV1_1_METHOD) && defined(HAVE_TLSV1_1_SERVER_METHOD) && \
          defined(HAVE_TLSV1_1_CLIENT_METHOD)
      OSSL_SSL_METHOD_ENTRY(TLSv1_1),
      OSSL_SSL_METHOD_ENTRY(TLSv1_1_server),
      OSSL_SSL_METHOD_ENTRY(TLSv1_1_client),
  #endif
  #if defined(HAVE_SSLV2_METHOD) && defined(HAVE_SSLV2_SERVER_METHOD) && \
          defined(HAVE_SSLV2_CLIENT_METHOD)
      OSSL_SSL_METHOD_ENTRY(SSLv2),
      OSSL_SSL_METHOD_ENTRY(SSLv2_server),
      OSSL_SSL_METHOD_ENTRY(SSLv2_client),
  #endif
      OSSL_SSL_METHOD_ENTRY(SSLv3),
      OSSL_SSL_METHOD_ENTRY(SSLv3_server),
      OSSL_SSL_METHOD_ENTRY(SSLv3_client),
      OSSL_SSL_METHOD_ENTRY(SSLv23),
      OSSL_SSL_METHOD_ENTRY(SSLv23_server),
      OSSL_SSL_METHOD_ENTRY(SSLv23_client),
  #undef OSSL_SSL_METHOD_ENTRY
  };
  
  int ossl_ssl_ex_vcb_idx;
  int ossl_ssl_ex_store_p;
  int ossl_ssl_ex_ptr_idx;
  int ossl_ssl_ex_client_cert_cb_idx;
  int ossl_ssl_ex_tmp_dh_callback_idx;
  
  static void
  ossl_sslctx_free(void *ptr)
  {
      SSL_CTX *ctx = ptr;
      if(ctx && SSL_CTX_get_ex_data(ctx, ossl_ssl_ex_store_p)== (void*)1)
  	ctx->cert_store = NULL;
      SSL_CTX_free(ctx);
  }
  
  static const rb_data_type_t ossl_sslctx_type = {
      "OpenSSL/SSL/CTX",
      {
  	0, ossl_sslctx_free,
      },
      0, 0, RUBY_TYPED_FREE_IMMEDIATELY,
  };
  
  static VALUE
  ossl_sslctx_s_alloc(VALUE klass)
  {
      SSL_CTX *ctx;
      long mode = SSL_MODE_ENABLE_PARTIAL_WRITE;
  
  #ifdef SSL_MODE_RELEASE_BUFFERS
      mode |= SSL_MODE_RELEASE_BUFFERS;
  #endif
  
      ctx = SSL_CTX_new(SSLv23_method());
      if (!ctx) {
          ossl_raise(eSSLError, "SSL_CTX_new");
      }
      SSL_CTX_set_mode(ctx, mode);
      return TypedData_Wrap_Struct(klass, &ossl_sslctx_type, ctx);
  }
  
  /*
   * call-seq:
   *    ctx.ssl_version = :TLSv1
   *    ctx.ssl_version = "SSLv23_client"
   *
   * You can get a list of valid versions with OpenSSL::SSL::SSLContext::METHODS
   */
  static VALUE
  ossl_sslctx_set_ssl_version(VALUE self, VALUE ssl_method)
  {
      SSL_METHOD *method = NULL;
      const char *s;
      int i;
  
      SSL_CTX *ctx;
      if (RB_TYPE_P(ssl_method, T_SYMBOL))
  	s = rb_id2name(SYM2ID(ssl_method));
      else
  	s =  StringValuePtr(ssl_method);
      for (i = 0; i < numberof(ossl_ssl_method_tab); i++) {
          if (strcmp(ossl_ssl_method_tab[i].name, s) == 0) {
              method = ossl_ssl_method_tab[i].func();
              break;
          }
      }
      if (!method) {
          ossl_raise(rb_eArgError, "unknown SSL method `%s'.", s);
      }
      GetSSLCTX(self, ctx);
      if (SSL_CTX_set_ssl_version(ctx, method) != 1) {
          ossl_raise(eSSLError, "SSL_CTX_set_ssl_version");
      }
  
      return ssl_method;
  }
  
  /*
   * call-seq:
   *    SSLContext.new => ctx
   *    SSLContext.new(:TLSv1) => ctx
   *    SSLContext.new("SSLv23_client") => ctx
   *
   * You can get a list of valid methods with OpenSSL::SSL::SSLContext::METHODS
   */
  static VALUE
  ossl_sslctx_initialize(int argc, VALUE *argv, VALUE self)
  {
      VALUE ssl_method;
      int i;
  
      for(i = 0; i < numberof(ossl_sslctx_attrs); i++){
  	char buf[32];
  	snprintf(buf, sizeof(buf), "@%s", ossl_sslctx_attrs[i]);
  	rb_iv_set(self, buf, Qnil);
      }
      if (rb_scan_args(argc, argv, "01", &ssl_method) == 0){
          return self;
      }
      ossl_sslctx_set_ssl_version(self, ssl_method);
  
      return self;
  }
  
  static VALUE
  ossl_call_client_cert_cb(VALUE obj)
  {
      VALUE cb, ary, cert, key;
      SSL *ssl;
  
      GetSSL(obj, ssl);
      cb = (VALUE)SSL_get_ex_data(ssl, ossl_ssl_ex_client_cert_cb_idx);
      if (NIL_P(cb)) return Qfalse;
      ary = rb_funcall(cb, rb_intern("call"), 1, obj);
      Check_Type(ary, T_ARRAY);
      GetX509CertPtr(cert = rb_ary_entry(ary, 0));
      GetPKeyPtr(key = rb_ary_entry(ary, 1));
      ossl_ssl_set_x509(obj, cert);
      ossl_ssl_set_key(obj, key);
  
      return Qtrue;
  }
  
  static int
  ossl_client_cert_cb(SSL *ssl, X509 **x509, EVP_PKEY **pkey)
  {
      VALUE obj, success;
  
      obj = (VALUE)SSL_get_ex_data(ssl, ossl_ssl_ex_ptr_idx);
      success = rb_protect((VALUE(*)_((VALUE)))ossl_call_client_cert_cb,
                           obj, NULL);
      if (!RTEST(success)) return 0;
      *x509 = DupX509CertPtr(ossl_ssl_get_x509(obj));
      *pkey = DupPKeyPtr(ossl_ssl_get_key(obj));
  
      return 1;
  }
  
  #if !defined(OPENSSL_NO_DH)
  static VALUE
  ossl_call_tmp_dh_callback(VALUE *args)
  {
      SSL *ssl;
      VALUE cb, dh;
      EVP_PKEY *pkey;
  
      GetSSL(args[0], ssl);
      cb = (VALUE)SSL_get_ex_data(ssl, ossl_ssl_ex_tmp_dh_callback_idx);
      if (NIL_P(cb)) return Qfalse;
      dh = rb_funcall(cb, rb_intern("call"), 3, args[0], args[1], args[2]);
      pkey = GetPKeyPtr(dh);
      if (EVP_PKEY_type(pkey->type) != EVP_PKEY_DH) return Qfalse;
      ossl_ssl_set_tmp_dh(args[0], dh);
  
      return Qtrue;
  }
  
  static DH*
  ossl_tmp_dh_callback(SSL *ssl, int is_export, int keylength)
  {
      VALUE args[3], success;
  
      args[0] = (VALUE)SSL_get_ex_data(ssl, ossl_ssl_ex_ptr_idx);
      args[1] = INT2FIX(is_export);
      args[2] = INT2FIX(keylength);
      success = rb_protect((VALUE(*)_((VALUE)))ossl_call_tmp_dh_callback,
                           (VALUE)args, NULL);
      if (!RTEST(success)) return NULL;
  
      return GetPKeyPtr(ossl_ssl_get_tmp_dh(args[0]))->pkey.dh;
  }
  
  static DH*
  ossl_default_tmp_dh_callback(SSL *ssl, int is_export, int keylength)
  {
      rb_warning("using default DH parameters.");
  
      switch(keylength){
      case 512:
  	return OSSL_DEFAULT_DH_512;
      case 1024:
  	return OSSL_DEFAULT_DH_1024;
      }
      return NULL;
  }
  #endif /* OPENSSL_NO_DH */
  
  static int
  ossl_ssl_verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
  {
      VALUE cb;
      SSL *ssl;
  
      ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx());
      cb = (VALUE)SSL_get_ex_data(ssl, ossl_ssl_ex_vcb_idx);
      X509_STORE_CTX_set_ex_data(ctx, ossl_verify_cb_idx, (void*)cb);
      return ossl_verify_cb(preverify_ok, ctx);
  }
  
  static VALUE
  ossl_call_session_get_cb(VALUE ary)
  {
      VALUE ssl_obj, sslctx_obj, cb;
  
      Check_Type(ary, T_ARRAY);
      ssl_obj = rb_ary_entry(ary, 0);
  
      sslctx_obj = rb_iv_get(ssl_obj, "@context");
      if (NIL_P(sslctx_obj)) return Qnil;
      cb = rb_iv_get(sslctx_obj, "@session_get_cb");
      if (NIL_P(cb)) return Qnil;
  
      return rb_funcall(cb, rb_intern("call"), 1, ary);
  }
  
  /* this method is currently only called for servers (in OpenSSL <= 0.9.8e) */
  static SSL_SESSION *
  ossl_sslctx_session_get_cb(SSL *ssl, unsigned char *buf, int len, int *copy)
  {
      VALUE ary, ssl_obj, ret_obj;
      SSL_SESSION *sess;
      void *ptr;
      int state = 0;
  
      OSSL_Debug("SSL SESSION get callback entered");
      if ((ptr = SSL_get_ex_data(ssl, ossl_ssl_ex_ptr_idx)) == NULL)
      	return NULL;
      ssl_obj = (VALUE)ptr;
      ary = rb_ary_new2(2);
      rb_ary_push(ary, ssl_obj);
      rb_ary_push(ary, rb_str_new((const char *)buf, len));
  
      ret_obj = rb_protect((VALUE(*)_((VALUE)))ossl_call_session_get_cb, ary, &state);
      if (state) {
          rb_ivar_set(ssl_obj, ID_callback_state, INT2NUM(state));
          return NULL;
      }
      if (!rb_obj_is_instance_of(ret_obj, cSSLSession))
          return NULL;
  
      SafeGetSSLSession(ret_obj, sess);
      *copy = 1;
  
      return sess;
  }
  
  static VALUE
  ossl_call_session_new_cb(VALUE ary)
  {
      VALUE ssl_obj, sslctx_obj, cb;
  
      Check_Type(ary, T_ARRAY);
      ssl_obj = rb_ary_entry(ary, 0);
  
      sslctx_obj = rb_iv_get(ssl_obj, "@context");
      if (NIL_P(sslctx_obj)) return Qnil;
      cb = rb_iv_get(sslctx_obj, "@session_new_cb");
      if (NIL_P(cb)) return Qnil;
  
      return rb_funcall(cb, rb_intern("call"), 1, ary);
  }
  
  /* return 1 normal.  return 0 removes the session */
  static int
  ossl_sslctx_session_new_cb(SSL *ssl, SSL_SESSION *sess)
  {
      VALUE ary, ssl_obj, sess_obj;
      void *ptr;
      int state = 0;
  
      OSSL_Debug("SSL SESSION new callback entered");
  
      if ((ptr = SSL_get_ex_data(ssl, ossl_ssl_ex_ptr_idx)) == NULL)
      	return 1;
      ssl_obj = (VALUE)ptr;
      sess_obj = rb_obj_alloc(cSSLSession);
      CRYPTO_add(&sess->references, 1, CRYPTO_LOCK_SSL_SESSION);
      DATA_PTR(sess_obj) = sess;
  
      ary = rb_ary_new2(2);
      rb_ary_push(ary, ssl_obj);
      rb_ary_push(ary, sess_obj);
  
      rb_protect((VALUE(*)_((VALUE)))ossl_call_session_new_cb, ary, &state);
      if (state) {
          rb_ivar_set(ssl_obj, ID_callback_state, INT2NUM(state));
      }
  
      /*
       * return 0 which means to OpenSSL that the session is still
       * valid (since we created Ruby Session object) and was not freed by us
       * with SSL_SESSION_free(). Call SSLContext#remove_session(sess) in
       * session_get_cb block if you don't want OpenSSL to cache the session
       * internally.
       */
      return 0;
  }
  
  static VALUE
  ossl_call_session_remove_cb(VALUE ary)
  {
      VALUE sslctx_obj, cb;
  
      Check_Type(ary, T_ARRAY);
      sslctx_obj = rb_ary_entry(ary, 0);
  
      cb = rb_iv_get(sslctx_obj, "@session_remove_cb");
      if (NIL_P(cb)) return Qnil;
  
      return rb_funcall(cb, rb_intern("call"), 1, ary);
  }
  
  static void
  ossl_sslctx_session_remove_cb(SSL_CTX *ctx, SSL_SESSION *sess)
  {
      VALUE ary, sslctx_obj, sess_obj;
      void *ptr;
      int state = 0;
  
      OSSL_Debug("SSL SESSION remove callback entered");
  
      if ((ptr = SSL_CTX_get_ex_data(ctx, ossl_ssl_ex_ptr_idx)) == NULL)
      	return;
      sslctx_obj = (VALUE)ptr;
      sess_obj = rb_obj_alloc(cSSLSession);
      CRYPTO_add(&sess->references, 1, CRYPTO_LOCK_SSL_SESSION);
      DATA_PTR(sess_obj) = sess;
  
      ary = rb_ary_new2(2);
      rb_ary_push(ary, sslctx_obj);
      rb_ary_push(ary, sess_obj);
  
      rb_protect((VALUE(*)_((VALUE)))ossl_call_session_remove_cb, ary, &state);
      if (state) {
  /*
    the SSL_CTX is frozen, nowhere to save state.
    there is no common accessor method to check it either.
          rb_ivar_set(sslctx_obj, ID_callback_state, INT2NUM(state));
  */
      }
  }
  
  static VALUE
  ossl_sslctx_add_extra_chain_cert_i(RB_BLOCK_CALL_FUNC_ARGLIST(i, arg))
  {
      X509 *x509;
      SSL_CTX *ctx;
  
      GetSSLCTX(arg, ctx);
      x509 = DupX509CertPtr(i);
      if(!SSL_CTX_add_extra_chain_cert(ctx, x509)){
  	ossl_raise(eSSLError, NULL);
      }
  
      return i;
  }
  
  static VALUE ossl_sslctx_setup(VALUE self);
  
  #ifdef HAVE_SSL_SET_TLSEXT_HOST_NAME
  static VALUE
  ossl_call_servername_cb(VALUE ary)
  {
      VALUE ssl_obj, sslctx_obj, cb, ret_obj;
  
      Check_Type(ary, T_ARRAY);
      ssl_obj = rb_ary_entry(ary, 0);
  
      sslctx_obj = rb_iv_get(ssl_obj, "@context");
      if (NIL_P(sslctx_obj)) return Qnil;
      cb = rb_iv_get(sslctx_obj, "@servername_cb");
      if (NIL_P(cb)) return Qnil;
  
      ret_obj = rb_funcall(cb, rb_intern("call"), 1, ary);
      if (rb_obj_is_kind_of(ret_obj, cSSLContext)) {
          SSL *ssl;
          SSL_CTX *ctx2;
  
          ossl_sslctx_setup(ret_obj);
          GetSSL(ssl_obj, ssl);
          GetSSLCTX(ret_obj, ctx2);
          SSL_set_SSL_CTX(ssl, ctx2);
      } else if (!NIL_P(ret_obj)) {
              ossl_raise(rb_eArgError, "servername_cb must return an OpenSSL::SSL::SSLContext object or nil");
      }
  
      return ret_obj;
  }
  
  static int
  ssl_servername_cb(SSL *ssl, int *ad, void *arg)
  {
      VALUE ary, ssl_obj;
      void *ptr;
      int state = 0;
      const char *servername = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);
  
      if (!servername)
          return SSL_TLSEXT_ERR_OK;
  
      if ((ptr = SSL_get_ex_data(ssl, ossl_ssl_ex_ptr_idx)) == NULL)
      	return SSL_TLSEXT_ERR_ALERT_FATAL;
      ssl_obj = (VALUE)ptr;
      ary = rb_ary_new2(2);
      rb_ary_push(ary, ssl_obj);
      rb_ary_push(ary, rb_str_new2(servername));
  
      rb_protect((VALUE(*)_((VALUE)))ossl_call_servername_cb, ary, &state);
      if (state) {
          rb_ivar_set(ssl_obj, ID_callback_state, INT2NUM(state));
          return SSL_TLSEXT_ERR_ALERT_FATAL;
      }
  
      return SSL_TLSEXT_ERR_OK;
  }
  #endif
  
  static void
  ssl_renegotiation_cb(const SSL *ssl)
  {
      VALUE ssl_obj, sslctx_obj, cb;
      void *ptr;
  
      if ((ptr = SSL_get_ex_data(ssl, ossl_ssl_ex_ptr_idx)) == NULL)
  	ossl_raise(eSSLError, "SSL object could not be retrieved");
      ssl_obj = (VALUE)ptr;
  
      sslctx_obj = rb_iv_get(ssl_obj, "@context");
      if (NIL_P(sslctx_obj)) return;
      cb = rb_iv_get(sslctx_obj, "@renegotiation_cb");
      if (NIL_P(cb)) return;
  
      (void) rb_funcall(cb, rb_intern("call"), 1, ssl_obj);
  }
  
  #ifdef HAVE_OPENSSL_NPN_NEGOTIATED
  static VALUE
  ssl_npn_encode_protocol_i(VALUE cur, VALUE encoded)
  {
      int len = RSTRING_LENINT(cur);
      char len_byte;
      if (len < 1 || len > 255)
  	ossl_raise(eSSLError, "Advertised protocol must have length 1..255");
      /* Encode the length byte */
      len_byte = len;
      rb_str_buf_cat(encoded, &len_byte, 1);
      rb_str_buf_cat(encoded, RSTRING_PTR(cur), len);
      return Qnil;
  }
  
  static void
  ssl_npn_encode_protocols(VALUE sslctx, VALUE protocols)
  {
      VALUE encoded = rb_str_new2("");
      rb_iterate(rb_each, protocols, ssl_npn_encode_protocol_i, encoded);
      StringValueCStr(encoded);
      rb_iv_set(sslctx, "@_protocols", encoded);
  }
  
  static int
  ssl_npn_advertise_cb(SSL *ssl, const unsigned char **out, unsigned int *outlen, void *arg)
  {
      VALUE sslctx_obj = (VALUE) arg;
      VALUE protocols = rb_iv_get(sslctx_obj, "@_protocols");
  
      *out = (const unsigned char *) RSTRING_PTR(protocols);
      *outlen = RSTRING_LENINT(protocols);
  
      return SSL_TLSEXT_ERR_OK;
  }
  
  static int
  ssl_npn_select_cb(SSL *s, unsigned char **out, unsigned char *outlen, const unsigned char *in, unsigned int inlen, void *arg)
  {
      int i = 0;
      VALUE sslctx_obj, cb, protocols, selected;
  
      sslctx_obj = (VALUE) arg;
      cb = rb_iv_get(sslctx_obj, "@npn_select_cb");
      protocols = rb_ary_new();
  
      /* The format is len_1|proto_1|...|len_n|proto_n\0 */
      while (in[i]) {
  	VALUE protocol = rb_str_new((const char *) &in[i + 1], in[i]);
  	rb_ary_push(protocols, protocol);
  	i += in[i] + 1;
      }
  
      selected = rb_funcall(cb, rb_intern("call"), 1, protocols);
      StringValue(selected);
      *out = (unsigned char *) StringValuePtr(selected);
      *outlen = RSTRING_LENINT(selected);
  
      return SSL_TLSEXT_ERR_OK;
  }
  #endif
  
  /* This function may serve as the entry point to support further
   * callbacks. */
  static void
  ssl_info_cb(const SSL *ssl, int where, int val)
  {
      int state = SSL_state(ssl);
  
      if ((where & SSL_CB_HANDSHAKE_START) &&
  	(state & SSL_ST_ACCEPT)) {
  	ssl_renegotiation_cb(ssl);
      }
  }
  
  /*
   * call-seq:
   *    ctx.setup => Qtrue # first time
   *    ctx.setup => nil # thereafter
   *
   * This method is called automatically when a new SSLSocket is created.
   * Normally you do not need to call this method (unless you are writing an
   * extension in C).
   */
  static VALUE
  ossl_sslctx_setup(VALUE self)
  {
      SSL_CTX *ctx;
      X509 *cert = NULL, *client_ca = NULL;
      X509_STORE *store;
      EVP_PKEY *key = NULL;
      char *ca_path = NULL, *ca_file = NULL;
      int i, verify_mode;
      VALUE val;
  
      if(OBJ_FROZEN(self)) return Qnil;
      GetSSLCTX(self, ctx);
  
  #if !defined(OPENSSL_NO_DH)
      if (RTEST(ossl_sslctx_get_tmp_dh_cb(self))){
  	SSL_CTX_set_tmp_dh_callback(ctx, ossl_tmp_dh_callback);
      }
      else{
  	SSL_CTX_set_tmp_dh_callback(ctx, ossl_default_tmp_dh_callback);
      }
  #endif
      SSL_CTX_set_ex_data(ctx, ossl_ssl_ex_ptr_idx, (void*)self);
  
      val = ossl_sslctx_get_cert_store(self);
      if(!NIL_P(val)){
  	/*
           * WORKAROUND:
  	 *   X509_STORE can count references, but
  	 *   X509_STORE_free() doesn't care it.
  	 *   So we won't increment it but mark it by ex_data.
  	 */
          store = GetX509StorePtr(val); /* NO NEED TO DUP */
          SSL_CTX_set_cert_store(ctx, store);
          SSL_CTX_set_ex_data(ctx, ossl_ssl_ex_store_p, (void*)1);
      }
  
      val = ossl_sslctx_get_extra_cert(self);
      if(!NIL_P(val)){
  	rb_block_call(val, rb_intern("each"), 0, 0, ossl_sslctx_add_extra_chain_cert_i, self);
      }
  
      /* private key may be bundled in certificate file. */
      val = ossl_sslctx_get_cert(self);
      cert = NIL_P(val) ? NULL : GetX509CertPtr(val); /* NO DUP NEEDED */
      val = ossl_sslctx_get_key(self);
      key = NIL_P(val) ? NULL : GetPKeyPtr(val); /* NO DUP NEEDED */
      if (cert && key) {
          if (!SSL_CTX_use_certificate(ctx, cert)) {
              /* Adds a ref => Safe to FREE */
              ossl_raise(eSSLError, "SSL_CTX_use_certificate");
          }
          if (!SSL_CTX_use_PrivateKey(ctx, key)) {
              /* Adds a ref => Safe to FREE */
              ossl_raise(eSSLError, "SSL_CTX_use_PrivateKey");
          }
          if (!SSL_CTX_check_private_key(ctx)) {
              ossl_raise(eSSLError, "SSL_CTX_check_private_key");
          }
      }
  
      val = ossl_sslctx_get_client_ca(self);
      if(!NIL_P(val)){
  	if (RB_TYPE_P(val, T_ARRAY)) {
  	    for(i = 0; i < RARRAY_LEN(val); i++){
  		client_ca = GetX509CertPtr(RARRAY_PTR(val)[i]);
          	if (!SSL_CTX_add_client_CA(ctx, client_ca)){
  		    /* Copies X509_NAME => FREE it. */
          	    ossl_raise(eSSLError, "SSL_CTX_add_client_CA");
          	}
  	    }
          }
  	else{
  	    client_ca = GetX509CertPtr(val); /* NO DUP NEEDED. */
              if (!SSL_CTX_add_client_CA(ctx, client_ca)){
  		/* Copies X509_NAME => FREE it. */
          	ossl_raise(eSSLError, "SSL_CTX_add_client_CA");
              }
  	}
      }
  
      val = ossl_sslctx_get_ca_file(self);
      ca_file = NIL_P(val) ? NULL : StringValuePtr(val);
      val = ossl_sslctx_get_ca_path(self);
      ca_path = NIL_P(val) ? NULL : StringValuePtr(val);
      if(ca_file || ca_path){
  	if (!SSL_CTX_load_verify_locations(ctx, ca_file, ca_path))
  	    rb_warning("can't set verify locations");
      }
  
      val = ossl_sslctx_get_verify_mode(self);
      verify_mode = NIL_P(val) ? SSL_VERIFY_NONE : NUM2INT(val);
      SSL_CTX_set_verify(ctx, verify_mode, ossl_ssl_verify_callback);
      if (RTEST(ossl_sslctx_get_client_cert_cb(self)))
  	SSL_CTX_set_client_cert_cb(ctx, ossl_client_cert_cb);
  
      val = ossl_sslctx_get_timeout(self);
      if(!NIL_P(val)) SSL_CTX_set_timeout(ctx, NUM2LONG(val));
  
      val = ossl_sslctx_get_verify_dep(self);
      if(!NIL_P(val)) SSL_CTX_set_verify_depth(ctx, NUM2INT(val));
  
      val = ossl_sslctx_get_options(self);
      if(!NIL_P(val)) {
      	SSL_CTX_set_options(ctx, NUM2LONG(val));
      } else {
  	SSL_CTX_set_options(ctx, SSL_OP_ALL);
      }
  
  #ifdef HAVE_OPENSSL_NPN_NEGOTIATED
      val = rb_iv_get(self, "@npn_protocols");
      if (!NIL_P(val)) {
  	ssl_npn_encode_protocols(self, val);
  	SSL_CTX_set_next_protos_advertised_cb(ctx, ssl_npn_advertise_cb, (void *) self);
  	OSSL_Debug("SSL NPN advertise callback added");
      }
      if (RTEST(rb_iv_get(self, "@npn_select_cb"))) {
  	SSL_CTX_set_next_proto_select_cb(ctx, ssl_npn_select_cb, (void *) self);
  	OSSL_Debug("SSL NPN select callback added");
      }
  #endif
  
      rb_obj_freeze(self);
  
      val = ossl_sslctx_get_sess_id_ctx(self);
      if (!NIL_P(val)){
  	StringValue(val);
  	if (!SSL_CTX_set_session_id_context(ctx, (unsigned char *)RSTRING_PTR(val),
  					    RSTRING_LENINT(val))){
  	    ossl_raise(eSSLError, "SSL_CTX_set_session_id_context");
  	}
      }
  
      if (RTEST(rb_iv_get(self, "@session_get_cb"))) {
  	SSL_CTX_sess_set_get_cb(ctx, ossl_sslctx_session_get_cb);
  	OSSL_Debug("SSL SESSION get callback added");
      }
      if (RTEST(rb_iv_get(self, "@session_new_cb"))) {
  	SSL_CTX_sess_set_new_cb(ctx, ossl_sslctx_session_new_cb);
  	OSSL_Debug("SSL SESSION new callback added");
      }
      if (RTEST(rb_iv_get(self, "@session_remove_cb"))) {
  	SSL_CTX_sess_set_remove_cb(ctx, ossl_sslctx_session_remove_cb);
  	OSSL_Debug("SSL SESSION remove callback added");
      }
  
  #ifdef HAVE_SSL_SET_TLSEXT_HOST_NAME
      val = rb_iv_get(self, "@servername_cb");
      if (!NIL_P(val)) {
          SSL_CTX_set_tlsext_servername_callback(ctx, ssl_servername_cb);
  	OSSL_Debug("SSL TLSEXT servername callback added");
      }
  #endif
  
      return Qtrue;
  }
  
  static VALUE
  ossl_ssl_cipher_to_ary(SSL_CIPHER *cipher)
  {
      VALUE ary;
      int bits, alg_bits;
  
      ary = rb_ary_new2(4);
      rb_ary_push(ary, rb_str_new2(SSL_CIPHER_get_name(cipher)));
      rb_ary_push(ary, rb_str_new2(SSL_CIPHER_get_version(cipher)));
      bits = SSL_CIPHER_get_bits(cipher, &alg_bits);
      rb_ary_push(ary, INT2FIX(bits));
      rb_ary_push(ary, INT2FIX(alg_bits));
  
      return ary;
  }
  
  /*
   * call-seq:
   *    ctx.ciphers => [[name, version, bits, alg_bits], ...]
   *
   * The list of ciphers configured for this context.
   */
  static VALUE
  ossl_sslctx_get_ciphers(VALUE self)
  {
      SSL_CTX *ctx;
      STACK_OF(SSL_CIPHER) *ciphers;
      SSL_CIPHER *cipher;
      VALUE ary;
      int i, num;
  
      GetSSLCTX(self, ctx);
      if(!ctx){
          rb_warning("SSL_CTX is not initialized.");
          return Qnil;
      }
      ciphers = ctx->cipher_list;
  
      if (!ciphers)
          return rb_ary_new();
  
      num = sk_SSL_CIPHER_num(ciphers);
      ary = rb_ary_new2(num);
      for(i = 0; i < num; i++){
          cipher = sk_SSL_CIPHER_value(ciphers, i);
          rb_ary_push(ary, ossl_ssl_cipher_to_ary(cipher));
      }
      return ary;
  }
  
  /*
   * call-seq:
   *    ctx.ciphers = "cipher1:cipher2:..."
   *    ctx.ciphers = [name, ...]
   *    ctx.ciphers = [[name, version, bits, alg_bits], ...]
   *
   * Sets the list of available ciphers for this context.  Note in a server
   * context some ciphers require the appropriate certificates.  For example, an
   * RSA cipher can only be chosen when an RSA certificate is available.
   *
   * See also OpenSSL::Cipher and OpenSSL::Cipher::ciphers
   */
  static VALUE
  ossl_sslctx_set_ciphers(VALUE self, VALUE v)
  {
      SSL_CTX *ctx;
      VALUE str, elem;
      int i;
  
      rb_check_frozen(self);
      if (NIL_P(v))
  	return v;
      else if (RB_TYPE_P(v, T_ARRAY)) {
          str = rb_str_new(0, 0);
          for (i = 0; i < RARRAY_LEN(v); i++) {
              elem = rb_ary_entry(v, i);
              if (RB_TYPE_P(elem, T_ARRAY)) elem = rb_ary_entry(elem, 0);
              elem = rb_String(elem);
              rb_str_append(str, elem);
              if (i < RARRAY_LEN(v)-1) rb_str_cat2(str, ":");
          }
      } else {
          str = v;
          StringValue(str);
      }
  
      GetSSLCTX(self, ctx);
      if(!ctx){
          ossl_raise(eSSLError, "SSL_CTX is not initialized.");
          return Qnil;
      }
      if (!SSL_CTX_set_cipher_list(ctx, RSTRING_PTR(str))) {
          ossl_raise(eSSLError, "SSL_CTX_set_cipher_list");
      }
  
      return v;
  }
  
  /*
   *  call-seq:
   *     ctx.session_add(session) -> true | false
   *
   * Adds +session+ to the session cache
   */
  static VALUE
  ossl_sslctx_session_add(VALUE self, VALUE arg)
  {
      SSL_CTX *ctx;
      SSL_SESSION *sess;
  
      GetSSLCTX(self, ctx);
      SafeGetSSLSession(arg, sess);
  
      return SSL_CTX_add_session(ctx, sess) == 1 ? Qtrue : Qfalse;
  }
  
  /*
   *  call-seq:
   *     ctx.session_remove(session) -> true | false
   *
   * Removes +session+ from the session cache
   */
  static VALUE
  ossl_sslctx_session_remove(VALUE self, VALUE arg)
  {
      SSL_CTX *ctx;
      SSL_SESSION *sess;
  
      GetSSLCTX(self, ctx);
      SafeGetSSLSession(arg, sess);
  
      return SSL_CTX_remove_session(ctx, sess) == 1 ? Qtrue : Qfalse;
  }
  
  /*
   *  call-seq:
   *     ctx.session_cache_mode -> Integer
   *
   * The current session cache mode.
   */
  static VALUE
  ossl_sslctx_get_session_cache_mode(VALUE self)
  {
      SSL_CTX *ctx;
  
      GetSSLCTX(self, ctx);
  
      return LONG2NUM(SSL_CTX_get_session_cache_mode(ctx));
  }
  
  /*
   *  call-seq:
   *     ctx.session_cache_mode=(integer) -> Integer
   *
   * Sets the SSL session cache mode.  Bitwise-or together the desired
   * SESSION_CACHE_* constants to set.  See SSL_CTX_set_session_cache_mode(3) for
   * details.
   */
  static VALUE
  ossl_sslctx_set_session_cache_mode(VALUE self, VALUE arg)
  {
      SSL_CTX *ctx;
  
      GetSSLCTX(self, ctx);
  
      SSL_CTX_set_session_cache_mode(ctx, NUM2LONG(arg));
  
      return arg;
  }
  
  /*
   *  call-seq:
   *     ctx.session_cache_size -> Integer
   *
   * Returns the current session cache size.  Zero is used to represent an
   * unlimited cache size.
   */
  static VALUE
  ossl_sslctx_get_session_cache_size(VALUE self)
  {
      SSL_CTX *ctx;
  
      GetSSLCTX(self, ctx);
  
      return LONG2NUM(SSL_CTX_sess_get_cache_size(ctx));
  }
  
  /*
   *  call-seq:
   *     ctx.session_cache_size=(integer) -> Integer
   *
   * Sets the session cache size.  Returns the previously valid session cache
   * size.  Zero is used to represent an unlimited session cache size.
   */
  static VALUE
  ossl_sslctx_set_session_cache_size(VALUE self, VALUE arg)
  {
      SSL_CTX *ctx;
  
      GetSSLCTX(self, ctx);
  
      SSL_CTX_sess_set_cache_size(ctx, NUM2LONG(arg));
  
      return arg;
  }
  
  /*
   *  call-seq:
   *     ctx.session_cache_stats -> Hash
   *
   * Returns a Hash containing the following keys:
   *
   * :accept:: Number of started SSL/TLS handshakes in server mode
   * :accept_good:: Number of established SSL/TLS sessions in server mode
   * :accept_renegotiate:: Number of start renegotiations in server mode
   * :cache_full:: Number of sessions that were removed due to cache overflow
   * :cache_hits:: Number of successfully reused connections
   * :cache_misses:: Number of sessions proposed by clients that were not found
   *                 in the cache
   * :cache_num:: Number of sessions in the internal session cache
   * :cb_hits:: Number of sessions retrieved from the external cache in server
   *            mode
   * :connect:: Number of started SSL/TLS handshakes in client mode
   * :connect_good:: Number of established SSL/TLS sessions in client mode
   * :connect_renegotiate:: Number of start renegotiations in client mode
   * :timeouts:: Number of sessions proposed by clients that were found in the
   *             cache but had expired due to timeouts
   */
  static VALUE
  ossl_sslctx_get_session_cache_stats(VALUE self)
  {
      SSL_CTX *ctx;
      VALUE hash;
  
      GetSSLCTX(self, ctx);
  
      hash = rb_hash_new();
      rb_hash_aset(hash, ID2SYM(rb_intern("cache_num")), LONG2NUM(SSL_CTX_sess_number(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("connect")), LONG2NUM(SSL_CTX_sess_connect(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("connect_good")), LONG2NUM(SSL_CTX_sess_connect_good(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("connect_renegotiate")), LONG2NUM(SSL_CTX_sess_connect_renegotiate(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("accept")), LONG2NUM(SSL_CTX_sess_accept(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("accept_good")), LONG2NUM(SSL_CTX_sess_accept_good(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("accept_renegotiate")), LONG2NUM(SSL_CTX_sess_accept_renegotiate(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("cache_hits")), LONG2NUM(SSL_CTX_sess_hits(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("cb_hits")), LONG2NUM(SSL_CTX_sess_cb_hits(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("cache_misses")), LONG2NUM(SSL_CTX_sess_misses(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("cache_full")), LONG2NUM(SSL_CTX_sess_cache_full(ctx)));
      rb_hash_aset(hash, ID2SYM(rb_intern("timeouts")), LONG2NUM(SSL_CTX_sess_timeouts(ctx)));
  
      return hash;
  }
  
  
  /*
   *  call-seq:
   *     ctx.flush_sessions(time | nil) -> self
   *
   * Removes sessions in the internal cache that have expired at +time+.
   */
  static VALUE
  ossl_sslctx_flush_sessions(int argc, VALUE *argv, VALUE self)
  {
      VALUE arg1;
      SSL_CTX *ctx;
      time_t tm = 0;
  
      rb_scan_args(argc, argv, "01", &arg1);
  
      GetSSLCTX(self, ctx);
  
      if (NIL_P(arg1)) {
          tm = time(0);
      } else if (rb_obj_is_instance_of(arg1, rb_cTime)) {
          tm = NUM2LONG(rb_funcall(arg1, rb_intern("to_i"), 0));
      } else {
          ossl_raise(rb_eArgError, "arg must be Time or nil");
      }
  
      SSL_CTX_flush_sessions(ctx, (long)tm);
  
      return self;
  }
  
  /*
   * SSLSocket class
   */
  #ifndef OPENSSL_NO_SOCK
  static void
  ossl_ssl_shutdown(SSL *ssl)
  {
      int i, rc;
  
      if (ssl) {
  	/* 4 is from SSL_smart_shutdown() of mod_ssl.c (v2.2.19) */
  	/* It says max 2x pending + 2x data = 4 */
  	for (i = 0; i < 4; ++i) {
  	    /*
  	     * Ignore the case SSL_shutdown returns -1. Empty handshake_func
  	     * must not happen.
  	     */
  	    if ((rc = SSL_shutdown(ssl)) != 0)
  		break;
  	}
  	SSL_clear(ssl);
  	ERR_clear_error();
      }
  }
  
  static void
  ossl_ssl_free(void *ssl)
  {
      SSL_free(ssl);
  }
  
  const rb_data_type_t ossl_ssl_type = {
      "OpenSSL/SSL",
      {
  	0, ossl_ssl_free,
      },
      0, 0, RUBY_TYPED_FREE_IMMEDIATELY,
  };
  
  static VALUE
  ossl_ssl_s_alloc(VALUE klass)
  {
      return TypedData_Wrap_Struct(klass, &ossl_ssl_type, NULL);
  }
  
  /*
   * call-seq:
   *    SSLSocket.new(io) => aSSLSocket
   *    SSLSocket.new(io, ctx) => aSSLSocket
   *
   * Creates a new SSL socket from +io+ which must be a real ruby object (not an
   * IO-like object that responds to read/write).
   *
   * If +ctx+ is provided the SSL Sockets initial params will be taken from
   * the context.
   *
   * The OpenSSL::Buffering module provides additional IO methods.
   *
   * This method will freeze the SSLContext if one is provided;
   * however, session management is still allowed in the frozen SSLContext.
   */
  static VALUE
  ossl_ssl_initialize(int argc, VALUE *argv, VALUE self)
  {
      VALUE io, ctx;
  
      if (rb_scan_args(argc, argv, "11", &io, &ctx) == 1) {
          ctx = rb_funcall(cSSLContext, rb_intern("new"), 0);
      }
      OSSL_Check_Kind(ctx, cSSLContext);
      Check_Type(io, T_FILE);
      ossl_ssl_set_io(self, io);
      ossl_ssl_set_ctx(self, ctx);
      ossl_ssl_set_sync_close(self, Qfalse);
      ossl_sslctx_setup(ctx);
  
      rb_iv_set(self, "@hostname", Qnil);
  
      rb_call_super(0, 0);
  
      return self;
  }
  
  static VALUE
  ossl_ssl_setup(VALUE self)
  {
      VALUE io, v_ctx, cb;
      SSL_CTX *ctx;
      SSL *ssl;
      rb_io_t *fptr;
  
      GetSSL(self, ssl);
      if(!ssl){
  #ifdef HAVE_SSL_SET_TLSEXT_HOST_NAME
  	VALUE hostname = rb_iv_get(self, "@hostname");
  #endif
  
          v_ctx = ossl_ssl_get_ctx(self);
          GetSSLCTX(v_ctx, ctx);
  
          ssl = SSL_new(ctx);
          if (!ssl) {
              ossl_raise(eSSLError, "SSL_new");
          }
          DATA_PTR(self) = ssl;
  
  #ifdef HAVE_SSL_SET_TLSEXT_HOST_NAME
          if (!NIL_P(hostname)) {
             if (SSL_set_tlsext_host_name(ssl, StringValuePtr(hostname)) != 1)
                 ossl_raise(eSSLError, "SSL_set_tlsext_host_name");
          }
  #endif
          io = ossl_ssl_get_io(self);
          GetOpenFile(io, fptr);
          rb_io_check_readable(fptr);
          rb_io_check_writable(fptr);
          SSL_set_fd(ssl, TO_SOCKET(FPTR_TO_FD(fptr)));
  	SSL_set_ex_data(ssl, ossl_ssl_ex_ptr_idx, (void*)self);
  	cb = ossl_sslctx_get_verify_cb(v_ctx);
  	SSL_set_ex_data(ssl, ossl_ssl_ex_vcb_idx, (void*)cb);
  	cb = ossl_sslctx_get_client_cert_cb(v_ctx);
  	SSL_set_ex_data(ssl, ossl_ssl_ex_client_cert_cb_idx, (void*)cb);
  	cb = ossl_sslctx_get_tmp_dh_cb(v_ctx);
  	SSL_set_ex_data(ssl, ossl_ssl_ex_tmp_dh_callback_idx, (void*)cb);
  	SSL_set_info_callback(ssl, ssl_info_cb);
      }
  
      return Qtrue;
  }
  
  #ifdef _WIN32
  #define ssl_get_error(ssl, ret) (errno = rb_w32_map_errno(WSAGetLastError()), SSL_get_error((ssl), (ret)))
  #else
  #define ssl_get_error(ssl, ret) SSL_get_error((ssl), (ret))
  #endif
  
  #define ossl_ssl_data_get_struct(v, ssl)		\
  do {							\
      GetSSL((v), (ssl)); 				\
      if (!(ssl)) {					\
          rb_warning("SSL session is not started yet.");  \
          return Qnil;					\
      }							\
  } while (0)
  
  static void
  write_would_block(int nonblock)
  {
      if (nonblock) {
          VALUE exc = ossl_exc_new(eSSLErrorWaitWritable, "write would block");
          rb_exc_raise(exc);
      }
  }
  
  static void
  read_would_block(int nonblock)
  {
      if (nonblock) {
          VALUE exc = ossl_exc_new(eSSLErrorWaitReadable, "read would block");
          rb_exc_raise(exc);
      }
  }
  
  static VALUE
  ossl_start_ssl(VALUE self, int (*func)(), const char *funcname,
  		int nonblock, int no_exception)
  {
      SSL *ssl;
      rb_io_t *fptr;
      int ret, ret2;
      VALUE cb_state;
  
      rb_ivar_set(self, ID_callback_state, Qnil);
  
      ossl_ssl_data_get_struct(self, ssl);
  
      GetOpenFile(ossl_ssl_get_io(self), fptr);
      for(;;){
  	ret = func(ssl);
  
          cb_state = rb_ivar_get(self, ID_callback_state);
          if (!NIL_P(cb_state))
              rb_jump_tag(NUM2INT(cb_state));
  
  	if (ret > 0)
  	    break;
  
  	switch((ret2 = ssl_get_error(ssl, ret))){
  	case SSL_ERROR_WANT_WRITE:
              if (no_exception) { return sym_wait_writable; }
              write_would_block(nonblock);
              rb_io_wait_writable(FPTR_TO_FD(fptr));
              continue;
  	case SSL_ERROR_WANT_READ:
              if (no_exception) { return sym_wait_readable; }
              read_would_block(nonblock);
              rb_io_wait_readable(FPTR_TO_FD(fptr));
              continue;
  	case SSL_ERROR_SYSCALL:
  	    if (errno) rb_sys_fail(funcname);
  	    ossl_raise(eSSLError, "%s SYSCALL returned=%d errno=%d state=%s", funcname, ret2, errno, SSL_state_string_long(ssl));
  	default:
  	    ossl_raise(eSSLError, "%s returned=%d errno=%d state=%s", funcname, ret2, errno, SSL_state_string_long(ssl));
  	}
      }
  
      return self;
  }
  
  /*
   * call-seq:
   *    ssl.connect => self
   *
   * Initiates an SSL/TLS handshake with a server.  The handshake may be started
   * after unencrypted data has been sent over the socket.
   */
  static VALUE
  ossl_ssl_connect(VALUE self)
  {
      ossl_ssl_setup(self);
      return ossl_start_ssl(self, SSL_connect, "SSL_connect", 0, 0);
  }
  
  /*
   * call-seq:
   *    ssl.connect_nonblock => self
   *
   * Initiates the SSL/TLS handshake as a client in non-blocking manner.
   *
   *   # emulates blocking connect
   *   begin
   *     ssl.connect_nonblock
   *   rescue IO::WaitReadable
   *     IO.select([s2])
   *     retry
   *   rescue IO::WaitWritable
   *     IO.select(nil, [s2])
   *     retry
   *   end
   *
   */
  static VALUE
  ossl_ssl_connect_nonblock(VALUE self)
  {
      ossl_ssl_setup(self);
      return ossl_start_ssl(self, SSL_connect, "SSL_connect", 1, 0);
  }
  
  /*
   * call-seq:
   *    ssl.accept => self
   *
   * Waits for a SSL/TLS client to initiate a handshake.  The handshake may be
   * started after unencrypted data has been sent over the socket.
   */
  static VALUE
  ossl_ssl_accept(VALUE self)
  {
      ossl_ssl_setup(self);
      return ossl_start_ssl(self, SSL_accept, "SSL_accept", 0, 0);
  }
  
  static int
  get_no_exception(VALUE opts)
  {
      if (!NIL_P(opts) && Qfalse == rb_hash_lookup2(opts, sym_exception, Qundef))
  	return 1;
      return 0;
  }
  
  /*
   * call-seq:
   *    ssl.accept_nonblock([options]) => self
   *
   * Initiates the SSL/TLS handshake as a server in non-blocking manner.
   *
   *   # emulates blocking accept
   *   begin
   *     ssl.accept_nonblock
   *   rescue IO::WaitReadable
   *     IO.select([s2])
   *     retry
   *   rescue IO::WaitWritable
   *     IO.select(nil, [s2])
   *     retry
   *   end
   *
   * By specifying `exception: false`, the options hash allows you to indicate
   * that accept_nonblock should not raise an IO::WaitReadable or
   * IO::WaitWritable exception, but return the symbol :wait_readable or
   * :wait_writable instead.
   */
  static VALUE
  ossl_ssl_accept_nonblock(int argc, VALUE *argv, VALUE self)
  {
      int no_exception;
      VALUE opts = Qnil;
  
      rb_scan_args(argc, argv, "0:", &opts);
      no_exception = get_no_exception(opts);
  
      ossl_ssl_setup(self);
      return ossl_start_ssl(self, SSL_accept, "SSL_accept", 1, no_exception);
  }
  
  static VALUE
  ossl_ssl_read_internal(int argc, VALUE *argv, VALUE self, int nonblock)
  {
      SSL *ssl;
      int ilen, nread = 0;
      int no_exception;
      VALUE len, str;
      rb_io_t *fptr;
      VALUE opts = Qnil;
  
      rb_scan_args(argc, argv, "11:", &len, &str, &opts);
      no_exception = get_no_exception(opts);
  
      ilen = NUM2INT(len);
      if(NIL_P(str)) str = rb_str_new(0, ilen);
      else{
          StringValue(str);
          rb_str_modify(str);
          rb_str_resize(str, ilen);
      }
      if(ilen == 0) return str;
  
      GetSSL(self, ssl);
      GetOpenFile(ossl_ssl_get_io(self), fptr);
      if (ssl) {
  	if(!nonblock && SSL_pending(ssl) <= 0)
  	    rb_thread_wait_fd(FPTR_TO_FD(fptr));
  	for (;;){
  	    nread = SSL_read(ssl, RSTRING_PTR(str), RSTRING_LENINT(str));
  	    switch(ssl_get_error(ssl, nread)){
  	    case SSL_ERROR_NONE:
  		goto end;
  	    case SSL_ERROR_ZERO_RETURN:
  		if (no_exception) { return Qnil; }
  		rb_eof_error();
  	    case SSL_ERROR_WANT_WRITE:
  		if (no_exception) { return sym_wait_writable; }
                  write_would_block(nonblock);
                  rb_io_wait_writable(FPTR_TO_FD(fptr));
                  continue;
  	    case SSL_ERROR_WANT_READ:
  		if (no_exception) { return sym_wait_readable; }
                  read_would_block(nonblock);
                  rb_io_wait_readable(FPTR_TO_FD(fptr));
  		continue;
  	    case SSL_ERROR_SYSCALL:
  		if(ERR_peek_error() == 0 && nread == 0) {
  		    if (no_exception) { return Qnil; }
  		    rb_eof_error();
  		}
  		rb_sys_fail(0);
  	    default:
  		ossl_raise(eSSLError, "SSL_read");
  	    }
          }
      }
      else {
          ID meth = nonblock ? rb_intern("read_nonblock") : rb_intern("sysread");
          rb_warning("SSL session is not started yet.");
          if (nonblock) {
            return rb_funcall(ossl_ssl_get_io(self), meth, 3, len, str, opts);
          } else {
            return rb_funcall(ossl_ssl_get_io(self), meth, 2, len, str);
          }
      }
  
    end:
      rb_str_set_len(str, nread);
      OBJ_TAINT(str);
  
      return str;
  }
  
  /*
   * call-seq:
   *    ssl.sysread(length) => string
   *    ssl.sysread(length, buffer) => buffer
   *
   * Reads +length+ bytes from the SSL connection.  If a pre-allocated +buffer+
   * is provided the data will be written into it.
   */
  static VALUE
  ossl_ssl_read(int argc, VALUE *argv, VALUE self)
  {
      return ossl_ssl_read_internal(argc, argv, self, 0);
  }
  
  /*
   * call-seq:
   *    ssl.sysread_nonblock(length) => string
   *    ssl.sysread_nonblock(length, buffer) => buffer
   *    ssl.sysread_nonblock(length[, buffer [, opts]) => buffer
   *
   * A non-blocking version of #sysread.  Raises an SSLError if reading would
   * block.  If "exception: false" is passed, this method returns a symbol of
   * :wait_readable, :wait_writable, or nil, rather than raising an exception.
   *
   * Reads +length+ bytes from the SSL connection.  If a pre-allocated +buffer+
   * is provided the data will be written into it.
   */
  static VALUE
  ossl_ssl_read_nonblock(int argc, VALUE *argv, VALUE self)
  {
      return ossl_ssl_read_internal(argc, argv, self, 1);
  }
  
  static VALUE
  ossl_ssl_write_internal(VALUE self, VALUE str, int nonblock, int no_exception)
  {
      SSL *ssl;
      int nwrite = 0;
      rb_io_t *fptr;
  
      StringValue(str);
      GetSSL(self, ssl);
      GetOpenFile(ossl_ssl_get_io(self), fptr);
  
      if (ssl) {
  	for (;;){
  	    nwrite = SSL_write(ssl, RSTRING_PTR(str), RSTRING_LENINT(str));
  	    switch(ssl_get_error(ssl, nwrite)){
  	    case SSL_ERROR_NONE:
  		goto end;
  	    case SSL_ERROR_WANT_WRITE:
  		if (no_exception) { return sym_wait_writable; }
                  write_would_block(nonblock);
                  rb_io_wait_writable(FPTR_TO_FD(fptr));
                  continue;
  	    case SSL_ERROR_WANT_READ:
  		if (no_exception) { return sym_wait_readable; }
                  read_would_block(nonblock);
                  rb_io_wait_readable(FPTR_TO_FD(fptr));
                  continue;
  	    case SSL_ERROR_SYSCALL:
  		if (errno) rb_sys_fail(0);
  	    default:
  		ossl_raise(eSSLError, "SSL_write");
  	    }
          }
      }
      else {
          ID id_syswrite = rb_intern("syswrite");
          rb_warning("SSL session is not started yet.");
  	return rb_funcall(ossl_ssl_get_io(self), id_syswrite, 1, str);
      }
  
    end:
      return INT2NUM(nwrite);
  }
  
  /*
   * call-seq:
   *    ssl.syswrite(string) => Integer
   *
   * Writes +string+ to the SSL connection.
   */
  static VALUE
  ossl_ssl_write(VALUE self, VALUE str)
  {
      return ossl_ssl_write_internal(self, str, 0, 0);
  }
  
  /*
   * call-seq:
   *    ssl.syswrite_nonblock(string) => Integer
   *
   * Writes +string+ to the SSL connection in a non-blocking manner.  Raises an
   * SSLError if writing would block.
   */
  static VALUE
  ossl_ssl_write_nonblock(int argc, VALUE *argv, VALUE self)
  {
      VALUE str;
      VALUE opts = Qnil;
      int no_exception;
  
      rb_scan_args(argc, argv, "1:", &str, &opts);
      no_exception = get_no_exception(opts);
  
      return ossl_ssl_write_internal(self, str, 1, no_exception);
  }
  
  /*
   * call-seq:
   *    ssl.sysclose => nil
   *
   * Shuts down the SSL connection and prepares it for another connection.
   */
  static VALUE
  ossl_ssl_close(VALUE self)
  {
      SSL *ssl;
      VALUE io;
  
      /* ossl_ssl_data_get_struct() is not usable here because it may return
       * from this function; */
  
      GetSSL(self, ssl);
  
      io = ossl_ssl_get_io(self);
      if (!RTEST(rb_funcall(io, rb_intern("closed?"), 0))) {
          if (ssl) {
              ossl_ssl_shutdown(ssl);
              SSL_free(ssl);
          }
          DATA_PTR(self) = NULL;
          if (RTEST(ossl_ssl_get_sync_close(self)))
              rb_funcall(io, rb_intern("close"), 0);
      }
  
      return Qnil;
  }
  
  /*
   * call-seq:
   *    ssl.cert => cert or nil
   *
   * The X509 certificate for this socket endpoint.
   */
  static VALUE
  ossl_ssl_get_cert(VALUE self)
  {
      SSL *ssl;
      X509 *cert = NULL;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      /*
       * Is this OpenSSL bug? Should add a ref?
       * TODO: Ask for.
       */
      cert = SSL_get_certificate(ssl); /* NO DUPs => DON'T FREE. */
  
      if (!cert) {
          return Qnil;
      }
      return ossl_x509_new(cert);
  }
  
  /*
   * call-seq:
   *    ssl.peer_cert => cert or nil
   *
   * The X509 certificate for this socket's peer.
   */
  static VALUE
  ossl_ssl_get_peer_cert(VALUE self)
  {
      SSL *ssl;
      X509 *cert = NULL;
      VALUE obj;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      cert = SSL_get_peer_certificate(ssl); /* Adds a ref => Safe to FREE. */
  
      if (!cert) {
          return Qnil;
      }
      obj = ossl_x509_new(cert);
      X509_free(cert);
  
      return obj;
  }
  
  /*
   * call-seq:
   *    ssl.peer_cert_chain => [cert, ...] or nil
   *
   * The X509 certificate chain for this socket's peer.
   */
  static VALUE
  ossl_ssl_get_peer_cert_chain(VALUE self)
  {
      SSL *ssl;
      STACK_OF(X509) *chain;
      X509 *cert;
      VALUE ary;
      int i, num;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      chain = SSL_get_peer_cert_chain(ssl);
      if(!chain) return Qnil;
      num = sk_X509_num(chain);
      ary = rb_ary_new2(num);
      for (i = 0; i < num; i++){
  	cert = sk_X509_value(chain, i);
  	rb_ary_push(ary, ossl_x509_new(cert));
      }
  
      return ary;
  }
  
  /*
  * call-seq:
  *    ssl.ssl_version => String
  *
  * Returns a String representing the SSL/TLS version that was negotiated
  * for the connection, for example "TLSv1.2".
  */
  static VALUE
  ossl_ssl_get_version(VALUE self)
  {
      SSL *ssl;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      return rb_str_new2(SSL_get_version(ssl));
  }
  
  /*
  * call-seq:
  *    ssl.cipher => [name, version, bits, alg_bits]
  *
  * The cipher being used for the current connection
  */
  static VALUE
  ossl_ssl_get_cipher(VALUE self)
  {
      SSL *ssl;
      SSL_CIPHER *cipher;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      cipher = (SSL_CIPHER *)SSL_get_current_cipher(ssl);
  
      return ossl_ssl_cipher_to_ary(cipher);
  }
  
  /*
   * call-seq:
   *    ssl.state => string
   *
   * A description of the current connection state.
   */
  static VALUE
  ossl_ssl_get_state(VALUE self)
  {
      SSL *ssl;
      VALUE ret;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      ret = rb_str_new2(SSL_state_string(ssl));
      if (ruby_verbose) {
          rb_str_cat2(ret, ": ");
          rb_str_cat2(ret, SSL_state_string_long(ssl));
      }
      return ret;
  }
  
  /*
   * call-seq:
   *    ssl.pending => Integer
   *
   * The number of bytes that are immediately available for reading
   */
  static VALUE
  ossl_ssl_pending(VALUE self)
  {
      SSL *ssl;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      return INT2NUM(SSL_pending(ssl));
  }
  
  /*
   * call-seq:
   *    ssl.session_reused? -> true | false
   *
   * Returns true if a reused session was negotiated during the handshake.
   */
  static VALUE
  ossl_ssl_session_reused(VALUE self)
  {
      SSL *ssl;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      switch(SSL_session_reused(ssl)) {
      case 1:	return Qtrue;
      case 0:	return Qfalse;
      default:	ossl_raise(eSSLError, "SSL_session_reused");
      }
  
      UNREACHABLE;
  }
  
  /*
   * call-seq:
   *    ssl.session = session -> session
   *
   * Sets the Session to be used when the connection is established.
   */
  static VALUE
  ossl_ssl_set_session(VALUE self, VALUE arg1)
  {
      SSL *ssl;
      SSL_SESSION *sess;
  
  /* why is ossl_ssl_setup delayed? */
      ossl_ssl_setup(self);
  
      ossl_ssl_data_get_struct(self, ssl);
  
      SafeGetSSLSession(arg1, sess);
  
      if (SSL_set_session(ssl, sess) != 1)
          ossl_raise(eSSLError, "SSL_set_session");
  
      return arg1;
  }
  
  /*
   * call-seq:
   *    ssl.verify_result => Integer
   *
   * Returns the result of the peer certificates verification.  See verify(1)
   * for error values and descriptions.
   *
   * If no peer certificate was presented X509_V_OK is returned.
   */
  static VALUE
  ossl_ssl_get_verify_result(VALUE self)
  {
      SSL *ssl;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      return INT2FIX(SSL_get_verify_result(ssl));
  }
  
  /*
   * call-seq:
   *    ssl.client_ca => [x509name, ...]
   *
   * Returns the list of client CAs. Please note that in contrast to
   * SSLContext#client_ca= no array of X509::Certificate is returned but
   * X509::Name instances of the CA's subject distinguished name.
   *
   * In server mode, returns the list set by SSLContext#client_ca=.
   * In client mode, returns the list of client CAs sent from the server.
   */
  static VALUE
  ossl_ssl_get_client_ca_list(VALUE self)
  {
      SSL *ssl;
      STACK_OF(X509_NAME) *ca;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      ca = SSL_get_client_CA_list(ssl);
      return ossl_x509name_sk2ary(ca);
  }
  
  # ifdef HAVE_OPENSSL_NPN_NEGOTIATED
  /*
   * call-seq:
   *    ssl.npn_protocol => String
   *
   * Returns the protocol string that was finally selected by the client
   * during the handshake.
   */
  static VALUE
  ossl_ssl_npn_protocol(VALUE self)
  {
      SSL *ssl;
      const unsigned char *out;
      unsigned int outlen;
  
      ossl_ssl_data_get_struct(self, ssl);
  
      SSL_get0_next_proto_negotiated(ssl, &out, &outlen);
      if (!outlen)
  	return Qnil;
      else
  	return rb_str_new((const char *) out, outlen);
  }
  # endif
  #endif /* !defined(OPENSSL_NO_SOCK) */
  
  void
  Init_ossl_ssl(void)
  {
      int i;
      VALUE ary;
  
  #if 0
      mOSSL = rb_define_module("OpenSSL"); /* let rdoc know about mOSSL */
  #endif
  
      ID_callback_state = rb_intern("@callback_state");
  
      ossl_ssl_ex_vcb_idx = SSL_get_ex_new_index(0,(void *)"ossl_ssl_ex_vcb_idx",0,0,0);
      ossl_ssl_ex_store_p = SSL_get_ex_new_index(0,(void *)"ossl_ssl_ex_store_p",0,0,0);
      ossl_ssl_ex_ptr_idx = SSL_get_ex_new_index(0,(void *)"ossl_ssl_ex_ptr_idx",0,0,0);
      ossl_ssl_ex_client_cert_cb_idx =
  	SSL_get_ex_new_index(0,(void *)"ossl_ssl_ex_client_cert_cb_idx",0,0,0);
      ossl_ssl_ex_tmp_dh_callback_idx =
  	SSL_get_ex_new_index(0,(void *)"ossl_ssl_ex_tmp_dh_callback_idx",0,0,0);
  
      /* Document-module: OpenSSL::SSL
       *
       * Use SSLContext to set up the parameters for a TLS (former SSL)
       * connection. Both client and server TLS connections are supported,
       * SSLSocket and SSLServer may be used in conjunction with an instance
       * of SSLContext to set up connections.
       */
      mSSL = rb_define_module_under(mOSSL, "SSL");
      /* Document-class: OpenSSL::SSL::SSLError
       *
       * Generic error class raised by SSLSocket and SSLContext.
       */
      eSSLError = rb_define_class_under(mSSL, "SSLError", eOSSLError);
      eSSLErrorWaitReadable = rb_define_class_under(mSSL, "SSLErrorWaitReadable", eSSLError);
      rb_include_module(eSSLErrorWaitReadable, rb_mWaitReadable);
      eSSLErrorWaitWritable = rb_define_class_under(mSSL, "SSLErrorWaitWritable", eSSLError);
      rb_include_module(eSSLErrorWaitWritable, rb_mWaitWritable);
  
      Init_ossl_ssl_session();
  
      /* Document-class: OpenSSL::SSL::SSLContext
       *
       * An SSLContext is used to set various options regarding certificates,
       * algorithms, verification, session caching, etc.  The SSLContext is
       * used to create an SSLSocket.
       *
       * All attributes must be set before creating an SSLSocket as the
       * SSLContext will be frozen afterward.
       *
       * The following attributes are available but don't show up in rdoc:
       * * ssl_version, cert, key, client_ca, ca_file, ca_path, timeout,
       * * verify_mode, verify_depth client_cert_cb, tmp_dh_callback,
       * * session_id_context, session_add_cb, session_new_cb, session_remove_cb
       */
      cSSLContext = rb_define_class_under(mSSL, "SSLContext", rb_cObject);
      rb_define_alloc_func(cSSLContext, ossl_sslctx_s_alloc);
  
      /*
       * Context certificate
       */
      rb_attr(cSSLContext, rb_intern("cert"), 1, 1, Qfalse);
  
      /*
       * Context private key
       */
      rb_attr(cSSLContext, rb_intern("key"), 1, 1, Qfalse);
  
      /*
       * A certificate or Array of certificates that will be sent to the client.
       */
      rb_attr(cSSLContext, rb_intern("client_ca"), 1, 1, Qfalse);
  
      /*
       * The path to a file containing a PEM-format CA certificate
       */
      rb_attr(cSSLContext, rb_intern("ca_file"), 1, 1, Qfalse);
  
      /*
       * The path to a directory containing CA certificates in PEM format.
       *
       * Files are looked up by subject's X509 name's hash value.
       */
      rb_attr(cSSLContext, rb_intern("ca_path"), 1, 1, Qfalse);
  
      /*
       * Maximum session lifetime.
       */
      rb_attr(cSSLContext, rb_intern("timeout"), 1, 1, Qfalse);
  
      /*
       * Session verification mode.
       *
       * Valid modes are VERIFY_NONE, VERIFY_PEER, VERIFY_CLIENT_ONCE,
       * VERIFY_FAIL_IF_NO_PEER_CERT and defined on OpenSSL::SSL
       */
      rb_attr(cSSLContext, rb_intern("verify_mode"), 1, 1, Qfalse);
  
      /*
       * Number of CA certificates to walk when verifying a certificate chain.
       */
      rb_attr(cSSLContext, rb_intern("verify_depth"), 1, 1, Qfalse);
  
      /*
       * A callback for additional certificate verification.  The callback is
       * invoked for each certificate in the chain.
       *
       * The callback is invoked with two values.  +preverify_ok+ indicates
       * indicates if the verification was passed (true) or not (false).
       * +store_context+ is an OpenSSL::X509::StoreContext containing the
       * context used for certificate verification.
       *
       * If the callback returns false verification is stopped.
       */
      rb_attr(cSSLContext, rb_intern("verify_callback"), 1, 1, Qfalse);
  
      /*
       * Sets various OpenSSL options.
       */
      rb_attr(cSSLContext, rb_intern("options"), 1, 1, Qfalse);
  
      /*
       * An OpenSSL::X509::Store used for certificate verification
       */
      rb_attr(cSSLContext, rb_intern("cert_store"), 1, 1, Qfalse);
  
      /*
       * An Array of extra X509 certificates to be added to the certificate
       * chain.
       */
      rb_attr(cSSLContext, rb_intern("extra_chain_cert"), 1, 1, Qfalse);
  
      /*
       * A callback invoked when a client certificate is requested by a server
       * and no certificate has been set.
       *
       * The callback is invoked with a Session and must return an Array
       * containing an OpenSSL::X509::Certificate and an OpenSSL::PKey.  If any
       * other value is returned the handshake is suspended.
       */
      rb_attr(cSSLContext, rb_intern("client_cert_cb"), 1, 1, Qfalse);
  
      /*
       * A callback invoked when DH parameters are required.
       *
       * The callback is invoked with the Session for the key exchange, an
       * flag indicating the use of an export cipher and the keylength
       * required.
       *
       * The callback must return an OpenSSL::PKey::DH instance of the correct
       * key length.
       */
      rb_attr(cSSLContext, rb_intern("tmp_dh_callback"), 1, 1, Qfalse);
  
      /*
       * Sets the context in which a session can be reused.  This allows
       * sessions for multiple applications to be distinguished, for example, by
       * name.
       */
      rb_attr(cSSLContext, rb_intern("session_id_context"), 1, 1, Qfalse);
  
      /*
       * A callback invoked on a server when a session is proposed by the client
       * but the session could not be found in the server's internal cache.
       *
       * The callback is invoked with the SSLSocket and session id.  The
       * callback may return a Session from an external cache.
       */
      rb_attr(cSSLContext, rb_intern("session_get_cb"), 1, 1, Qfalse);
  
      /*
       * A callback invoked when a new session was negotiated.
       *
       * The callback is invoked with an SSLSocket.  If false is returned the
       * session will be removed from the internal cache.
       */
      rb_attr(cSSLContext, rb_intern("session_new_cb"), 1, 1, Qfalse);
  
      /*
       * A callback invoked when a session is removed from the internal cache.
       *
       * The callback is invoked with an SSLContext and a Session.
       */
      rb_attr(cSSLContext, rb_intern("session_remove_cb"), 1, 1, Qfalse);
  
  #ifdef HAVE_SSL_SET_TLSEXT_HOST_NAME
      /*
       * A callback invoked at connect time to distinguish between multiple
       * server names.
       *
       * The callback is invoked with an SSLSocket and a server name.  The
       * callback must return an SSLContext for the server name or nil.
       */
      rb_attr(cSSLContext, rb_intern("servername_cb"), 1, 1, Qfalse);
  #endif
      /*
       * A callback invoked whenever a new handshake is initiated. May be used
       * to disable renegotiation entirely.
       *
       * The callback is invoked with the active SSLSocket. The callback's
       * return value is irrelevant, normal return indicates "approval" of the
       * renegotiation and will continue the process. To forbid renegotiation
       * and to cancel the process, an Error may be raised within the callback.
       *
       * === Disable client renegotiation
       *
       * When running a server, it is often desirable to disable client
       * renegotiation entirely. You may use a callback as follows to implement
       * this feature:
       *
       *   num_handshakes = 0
       *   ctx.renegotiation_cb = lambda do |ssl|
       *     num_handshakes += 1
       *     raise RuntimeError.new("Client renegotiation disabled") if num_handshakes > 1
       *   end
       */
      rb_attr(cSSLContext, rb_intern("renegotiation_cb"), 1, 1, Qfalse);
  #ifdef HAVE_OPENSSL_NPN_NEGOTIATED
      /*
       * An Enumerable of Strings. Each String represents a protocol to be
       * advertised as the list of supported protocols for Next Protocol
       * Negotiation. Supported in OpenSSL 1.0.1 and higher. Has no effect
       * on the client side. If not set explicitly, the NPN extension will
       * not be sent by the server in the handshake.
       *
       * === Example
       *
       *   ctx.npn_protocols = ["http/1.1", "spdy/2"]
       */
      rb_attr(cSSLContext, rb_intern("npn_protocols"), 1, 1, Qfalse);
      /*
       * A callback invoked on the client side when the client needs to select
       * a protocol from the list sent by the server. Supported in OpenSSL 1.0.1
       * and higher. The client MUST select a protocol of those advertised by
       * the server. If none is acceptable, raising an error in the callback
       * will cause the handshake to fail. Not setting this callback explicitly
       * means not supporting the NPN extension on the client - any protocols
       * advertised by the server will be ignored.
       *
       * === Example
       *
       *   ctx.npn_select_cb = lambda do |protocols|
       *     #inspect the protocols and select one
       *     protocols.first
       *   end
       */
      rb_attr(cSSLContext, rb_intern("npn_select_cb"), 1, 1, Qfalse);
  #endif
  
      rb_define_alias(cSSLContext, "ssl_timeout", "timeout");
      rb_define_alias(cSSLContext, "ssl_timeout=", "timeout=");
      rb_define_method(cSSLContext, "initialize",  ossl_sslctx_initialize, -1);
      rb_define_method(cSSLContext, "ssl_version=", ossl_sslctx_set_ssl_version, 1);
      rb_define_method(cSSLContext, "ciphers",     ossl_sslctx_get_ciphers, 0);
      rb_define_method(cSSLContext, "ciphers=",    ossl_sslctx_set_ciphers, 1);
  
      rb_define_method(cSSLContext, "setup", ossl_sslctx_setup, 0);
  
      /*
       * No session caching for client or server
       */
      rb_define_const(cSSLContext, "SESSION_CACHE_OFF", LONG2FIX(SSL_SESS_CACHE_OFF));
  
      /*
       * Client sessions are added to the session cache
       */
      rb_define_const(cSSLContext, "SESSION_CACHE_CLIENT", LONG2FIX(SSL_SESS_CACHE_CLIENT)); /* doesn't actually do anything in 0.9.8e */
  
      /*
       * Server sessions are added to the session cache
       */
      rb_define_const(cSSLContext, "SESSION_CACHE_SERVER", LONG2FIX(SSL_SESS_CACHE_SERVER));
  
      /*
       * Both client and server sessions are added to the session cache
       */
      rb_define_const(cSSLContext, "SESSION_CACHE_BOTH", LONG2FIX(SSL_SESS_CACHE_BOTH)); /* no different than CACHE_SERVER in 0.9.8e */
  
      /*
       * Normally the session cache is checked for expired sessions every 255
       * connections.  Since this may lead to a delay that cannot be controlled,
       * the automatic flushing may be disabled and #flush_sessions can be
       * called explicitly.
       */
      rb_define_const(cSSLContext, "SESSION_CACHE_NO_AUTO_CLEAR", LONG2FIX(SSL_SESS_CACHE_NO_AUTO_CLEAR));
  
      /*
       * Always perform external lookups of sessions even if they are in the
       * internal cache.
       *
       * This flag has no effect on clients
       */
      rb_define_const(cSSLContext, "SESSION_CACHE_NO_INTERNAL_LOOKUP", LONG2FIX(SSL_SESS_CACHE_NO_INTERNAL_LOOKUP));
  
      /*
       * Never automatically store sessions in the internal store.
       */
      rb_define_const(cSSLContext, "SESSION_CACHE_NO_INTERNAL_STORE", LONG2FIX(SSL_SESS_CACHE_NO_INTERNAL_STORE));
  
      /*
       * Enables both SESSION_CACHE_NO_INTERNAL_LOOKUP and
       * SESSION_CACHE_NO_INTERNAL_STORE.
       */
      rb_define_const(cSSLContext, "SESSION_CACHE_NO_INTERNAL", LONG2FIX(SSL_SESS_CACHE_NO_INTERNAL));
  
      rb_define_method(cSSLContext, "session_add",     ossl_sslctx_session_add, 1);
      rb_define_method(cSSLContext, "session_remove",     ossl_sslctx_session_remove, 1);
      rb_define_method(cSSLContext, "session_cache_mode",     ossl_sslctx_get_session_cache_mode, 0);
      rb_define_method(cSSLContext, "session_cache_mode=",     ossl_sslctx_set_session_cache_mode, 1);
      rb_define_method(cSSLContext, "session_cache_size",     ossl_sslctx_get_session_cache_size, 0);
      rb_define_method(cSSLContext, "session_cache_size=",     ossl_sslctx_set_session_cache_size, 1);
      rb_define_method(cSSLContext, "session_cache_stats",     ossl_sslctx_get_session_cache_stats, 0);
      rb_define_method(cSSLContext, "flush_sessions",     ossl_sslctx_flush_sessions, -1);
  
      ary = rb_ary_new2(numberof(ossl_ssl_method_tab));
      for (i = 0; i < numberof(ossl_ssl_method_tab); i++) {
          rb_ary_push(ary, ID2SYM(rb_intern(ossl_ssl_method_tab[i].name)));
      }
      rb_obj_freeze(ary);
      /* The list of available SSL/TLS methods */
      rb_define_const(cSSLContext, "METHODS", ary);
  
      /*
       * Document-class: OpenSSL::SSL::SSLSocket
       *
       * The following attributes are available but don't show up in rdoc.
       * * io, context, sync_close
       *
       */
      cSSLSocket = rb_define_class_under(mSSL, "SSLSocket", rb_cObject);
  #ifdef OPENSSL_NO_SOCK
      rb_define_method(cSSLSocket, "initialize", rb_notimplement, -1);
  #else
      rb_define_alloc_func(cSSLSocket, ossl_ssl_s_alloc);
      for(i = 0; i < numberof(ossl_ssl_attr_readers); i++)
          rb_attr(cSSLSocket, rb_intern(ossl_ssl_attr_readers[i]), 1, 0, Qfalse);
      for(i = 0; i < numberof(ossl_ssl_attrs); i++)
          rb_attr(cSSLSocket, rb_intern(ossl_ssl_attrs[i]), 1, 1, Qfalse);
      rb_define_alias(cSSLSocket, "to_io", "io");
      rb_define_method(cSSLSocket, "initialize", ossl_ssl_initialize, -1);
      rb_define_method(cSSLSocket, "connect",    ossl_ssl_connect, 0);
      rb_define_method(cSSLSocket, "connect_nonblock",    ossl_ssl_connect_nonblock, 0);
      rb_define_method(cSSLSocket, "accept",     ossl_ssl_accept, 0);
      rb_define_method(cSSLSocket, "accept_nonblock", ossl_ssl_accept_nonblock, -1);
      rb_define_method(cSSLSocket, "sysread",    ossl_ssl_read, -1);
      rb_define_private_method(cSSLSocket, "sysread_nonblock",    ossl_ssl_read_nonblock, -1);
      rb_define_method(cSSLSocket, "syswrite",   ossl_ssl_write, 1);
      rb_define_private_method(cSSLSocket, "syswrite_nonblock",    ossl_ssl_write_nonblock, -1);
      rb_define_method(cSSLSocket, "sysclose",   ossl_ssl_close, 0);
      rb_define_method(cSSLSocket, "cert",       ossl_ssl_get_cert, 0);
      rb_define_method(cSSLSocket, "peer_cert",  ossl_ssl_get_peer_cert, 0);
      rb_define_method(cSSLSocket, "peer_cert_chain", ossl_ssl_get_peer_cert_chain, 0);
      rb_define_method(cSSLSocket, "ssl_version",    ossl_ssl_get_version, 0);
      rb_define_method(cSSLSocket, "cipher",     ossl_ssl_get_cipher, 0);
      rb_define_method(cSSLSocket, "state",      ossl_ssl_get_state, 0);
      rb_define_method(cSSLSocket, "pending",    ossl_ssl_pending, 0);
      rb_define_method(cSSLSocket, "session_reused?",    ossl_ssl_session_reused, 0);
      /* implementation of OpenSSL::SSL::SSLSocket#session is in lib/openssl/ssl.rb */
      rb_define_method(cSSLSocket, "session=",    ossl_ssl_set_session, 1);
      rb_define_method(cSSLSocket, "verify_result", ossl_ssl_get_verify_result, 0);
      rb_define_method(cSSLSocket, "client_ca", ossl_ssl_get_client_ca_list, 0);
  # ifdef HAVE_OPENSSL_NPN_NEGOTIATED
      rb_define_method(cSSLSocket, "npn_protocol", ossl_ssl_npn_protocol, 0);
  # endif
  #endif
  
  #define ossl_ssl_def_const(x) rb_define_const(mSSL, #x, INT2NUM(SSL_##x))
  
      ossl_ssl_def_const(VERIFY_NONE);
      ossl_ssl_def_const(VERIFY_PEER);
      ossl_ssl_def_const(VERIFY_FAIL_IF_NO_PEER_CERT);
      ossl_ssl_def_const(VERIFY_CLIENT_ONCE);
      /* Introduce constants included in OP_ALL.  These constants are mostly for
       * unset some bits in OP_ALL such as;
       *   ctx.options = OP_ALL & ~OP_DONT_INSERT_EMPTY_FRAGMENTS
       */
      ossl_ssl_def_const(OP_MICROSOFT_SESS_ID_BUG);
      ossl_ssl_def_const(OP_NETSCAPE_CHALLENGE_BUG);
      ossl_ssl_def_const(OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG);
      ossl_ssl_def_const(OP_SSLREF2_REUSE_CERT_TYPE_BUG);
      ossl_ssl_def_const(OP_MICROSOFT_BIG_SSLV3_BUFFER);
  #if defined(SSL_OP_MSIE_SSLV2_RSA_PADDING)
      ossl_ssl_def_const(OP_MSIE_SSLV2_RSA_PADDING);
  #endif
      ossl_ssl_def_const(OP_SSLEAY_080_CLIENT_DH_BUG);
      ossl_ssl_def_const(OP_TLS_D5_BUG);
      ossl_ssl_def_const(OP_TLS_BLOCK_PADDING_BUG);
      ossl_ssl_def_const(OP_DONT_INSERT_EMPTY_FRAGMENTS);
      ossl_ssl_def_const(OP_ALL);
  #if defined(SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION)
      ossl_ssl_def_const(OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
  #endif
  #if defined(SSL_OP_SINGLE_ECDH_USE)
      ossl_ssl_def_const(OP_SINGLE_ECDH_USE);
  #endif
      ossl_ssl_def_const(OP_SINGLE_DH_USE);
      ossl_ssl_def_const(OP_EPHEMERAL_RSA);
  #if defined(SSL_OP_CIPHER_SERVER_PREFERENCE)
      ossl_ssl_def_const(OP_CIPHER_SERVER_PREFERENCE);
  #endif
      ossl_ssl_def_const(OP_TLS_ROLLBACK_BUG);
      ossl_ssl_def_const(OP_NO_SSLv2);
      ossl_ssl_def_const(OP_NO_SSLv3);
      ossl_ssl_def_const(OP_NO_TLSv1);
  #if defined(SSL_OP_NO_TLSv1_1)
      ossl_ssl_def_const(OP_NO_TLSv1_1);
  #endif
  #if defined(SSL_OP_NO_TLSv1_2)
      ossl_ssl_def_const(OP_NO_TLSv1_2);
  #endif
  #if defined(SSL_OP_NO_TICKET)
      ossl_ssl_def_const(OP_NO_TICKET);
  #endif
  #if defined(SSL_OP_NO_COMPRESSION)
      ossl_ssl_def_const(OP_NO_COMPRESSION);
  #endif
      ossl_ssl_def_const(OP_PKCS1_CHECK_1);
      ossl_ssl_def_const(OP_PKCS1_CHECK_2);
      ossl_ssl_def_const(OP_NETSCAPE_CA_DN_BUG);
      ossl_ssl_def_const(OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG);
  
  #undef rb_intern
      sym_exception = ID2SYM(rb_intern("exception"));
      sym_wait_readable = ID2SYM(rb_intern("wait_readable"));
      sym_wait_writable = ID2SYM(rb_intern("wait_writable"));
  }
  