From 45c85576f8da0f4d4bcb0ad1ae7eea1943a27d2f Mon Sep 17 00:00:00 2001
From: Zack Owens <zowens2009@gmail.com>
Date: Thu, 15 May 2014 13:11:05 -0400
Subject: [PATCH] Adding EnableECDH to Context

---
 ctx.go | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/ctx.go b/ctx.go
index e579d6b..f9e1451 100644
--- a/ctx.go
+++ b/ctx.go
@@ -46,6 +46,18 @@ static long SSL_CTX_add_extra_chain_cert_not_a_macro(SSL_CTX* ctx, X509 *cert) {
     return SSL_CTX_add_extra_chain_cert(ctx, cert);
 }
 
+static long SSL_CTX_auto_enable_ecdh_not_a_macro(SSL_CTX* ctx) {
+#if defined(SSL_CTX_set_ecdh_auto)
+        return SSL_CTX_set_ecdh_auto(ctx, 1);
+#else
+        EC_KEY *k = NULL;
+        k = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
+        long result = SSL_CTX_set_tmp_ecdh(ctx, k);
+        EC_KEY_free(k);
+        return result;
+#endif
+}
+
 #ifndef SSL_MODE_RELEASE_BUFFERS
 #define SSL_MODE_RELEASE_BUFFERS 0
 #endif
@@ -198,6 +210,17 @@ func NewCtxFromFiles(cert_file string, key_file string) (*Ctx, error) {
 	return ctx, nil
 }
 
+// EnableECDH sets the elliptic curve on the context to enable an
+// ECDH cipher suite to be selected.
+func (c *Ctx) EnableECDH() error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+	if int(C.SSL_CTX_auto_enable_ecdh_not_a_macro(c.ctx)) != 1 {
+		return errorFromErrorQueue()
+	}
+	return nil
+}
+
 // UseCertificate configures the context to present the given certificate to
 // peers.
 func (c *Ctx) UseCertificate(cert *Certificate) error {