diff --git a/ChangeLog b/ChangeLog
index 7728d88928..ffaef1d126 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sun May 22 19:11:35 2005  GOTOU Yuuzou  <gotoyuzo@notwork.org>
+
+	* ext/openssl/lib/openssl/ssl.rb (OpenSSL::SSL::SSLServer#intialize):
+	  should initialize session id context. [ruby-core:4663]
+
+	* ext/openssl/ossl_ssl.c (ossl_sslctx_setup): add session id support.
+
 Sun May 22 12:30:58 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* intern.h, parse.y (ruby_pragma): removed.  fixed: [ruby-dev:26198]
diff --git a/ext/openssl/lib/openssl/ssl.rb b/ext/openssl/lib/openssl/ssl.rb
index 441890865b..9b287fc939 100644
--- a/ext/openssl/lib/openssl/ssl.rb
+++ b/ext/openssl/lib/openssl/ssl.rb
@@ -98,6 +98,10 @@ module OpenSSL
       def initialize(svr, ctx)
         @svr = svr
         @ctx = ctx
+        unless ctx.session_id_context
+          session_id = OpenSSL::Digest::MD5.hexdigest($0)
+          @ctx.session_id_context = session_id
+        end
         @start_immediately = true
       end
 
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index f494a59bbe..7a376223a9 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -44,6 +44,7 @@ VALUE cSSLSocket;
 #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_get((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")
@@ -59,13 +60,13 @@ VALUE cSSLSocket;
 #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 char *ossl_sslctx_attrs[] = {
     "cert", "key", "client_ca", "ca_file", "ca_path",
     "timeout", "verify_mode", "verify_depth",
     "verify_callback", "options", "cert_store", "extra_chain_cert",
-    "client_cert_cb",
-    "tmp_dh_callback",
+    "client_cert_cb", "tmp_dh_callback", "session_id_context",
 };
 
 #define ossl_ssl_get_io(o)           rb_iv_get((o),"@io")
@@ -390,6 +391,15 @@ ossl_sslctx_setup(VALUE self)
     if(!NIL_P(val)) SSL_CTX_set_options(ctx, NUM2LONG(val));
     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, RSTRING(val)->ptr,
+					    RSTRING(val)->len)){
+	    ossl_raise(eSSLError, "SSL_CTX_set_session_id_context:");
+	}
+    }
+
     return Qtrue;
 }