Enable ECDHE support in httpd via a SSLECDHCurve option. This specifies the

named curve to use when generating ephemeral EC keys for an ECDHE-based
cipher suite, or can be set to `none' to disable. The default is to use
a prime256v1 curve.

yay^Wok djm@

6 files changed, 58 insertions, 5 deletions

diff --git a/usr.sbin/httpd/conf/httpd.conf b/usr.sbin/httpd/conf/httpd.conf
index 2a9715c582b..6fa0cbc6cbf 100644
--- a/usr.sbin/httpd/conf/httpd.conf
+++ b/usr.sbin/httpd/conf/httpd.conf
@@ -1,4 +1,4 @@
-#	$OpenBSD: httpd.conf,v 1.27 2013/07/12 16:30:41 otto Exp $
+#	$OpenBSD: httpd.conf,v 1.28 2013/07/16 13:02:16 jsing Exp $
 #
 # Based upon the NCSA server configuration files originally by Rob McCool.
 #
@@ -1035,6 +1035,11 @@ SSLEngine on
 #   See the mod_ssl documentation for a complete list.
 #SSLCipherSuite ALL:!ADH:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP
 
+#   SSL ECDH Curve:
+#   Named curve to use when generating ephemeral EC keys for an
+#   ECDHE-based cipher suite, or `none' to disable.
+SSLECDHCurve prime256v1
+
 #   SSL Honor Cipher Order:
 #   If on, use server's order of preference for ciphers.
 #SSLHonorCipherOrder on
diff --git a/usr.sbin/httpd/conf/httpd.conf-dist b/usr.sbin/httpd/conf/httpd.conf-dist
index e71f6169c74..b5a4c2e0aaa 100644
--- a/usr.sbin/httpd/conf/httpd.conf-dist
+++ b/usr.sbin/httpd/conf/httpd.conf-dist
@@ -1045,6 +1045,11 @@ SSLEngine on
 #   See the mod_ssl documentation for a complete list.
 SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL
 
+#   SSL ECDH Curve:
+#   Named curve to use when generating ephemeral EC keys for an
+#   ECDHE-based cipher suite, or `none' to disable.
+SSLECDHCurve prime256v1
+
 #   SSL Honor Cipher Order:
 #   If on, use server's order of preference for ciphers.
 #SSLHonorCipherOrder on
diff --git a/usr.sbin/httpd/src/modules/ssl/mod_ssl.c b/usr.sbin/httpd/src/modules/ssl/mod_ssl.c
index 3a50bda9b8d..01133e25485 100644
--- a/usr.sbin/httpd/src/modules/ssl/mod_ssl.c
+++ b/usr.sbin/httpd/src/modules/ssl/mod_ssl.c
@@ -74,7 +74,7 @@
  *  identify the module to SCCS `what' and RCS `ident' commands
  */
 static char const sccsid[] = "@(#) mod_ssl/" MOD_SSL_VERSION " >";
-static char const rcsid[]  = "$Id: mod_ssl.c,v 1.12 2013/07/16 11:32:05 jsing Exp $";
+static char const rcsid[]  = "$Id: mod_ssl.c,v 1.13 2013/07/16 13:02:16 jsing Exp $";
 
 /*
  *  the table of configuration directives we provide
@@ -113,6 +113,9 @@ static command_rec ssl_config_cmds[] = {
     AP_ALL_CMD(CipherSuite, TAKE1,
                "Colon-delimited list of permitted SSL Ciphers "
                "(`XXX:...:XXX' - see manual)")
+    AP_SRV_CMD(ECDHCurve, TAKE1,
+               "Name of ECDH curve to use for ephemeral EC keys "
+               "(`curve' - see manual)")
     AP_SRV_CMD(CertificateFile, TAKE1,
                "SSL Server Certificate file "
                "(`/path/to/file' - PEM or DER encoded)")
diff --git a/usr.sbin/httpd/src/modules/ssl/mod_ssl.h b/usr.sbin/httpd/src/modules/ssl/mod_ssl.h
index 22c982b1401..4d88024b999 100644
--- a/usr.sbin/httpd/src/modules/ssl/mod_ssl.h
+++ b/usr.sbin/httpd/src/modules/ssl/mod_ssl.h
@@ -514,9 +514,10 @@ typedef struct {
     char        *szCACertificateFile;
     char        *szLogFile;
     char        *szCipherSuite;
+    int          nECDHCurve;
+    BOOL         bHonorCipherOrder;
     FILE        *fileLogFile;
     int          nLogLevel;
-    BOOL         bHonorCipherOrder;
     int          nVerifyDepth;
     ssl_verify_t nVerifyClient;
     X509        *pPublicCert[SSL_AIDX_MAX];
@@ -591,6 +592,7 @@ const char  *ssl_cmd_SSLCryptoDevice(cmd_parms *, char *, char *);
 const char  *ssl_cmd_SSLRandomSeed(cmd_parms *, char *, char *, char *, char *);
 const char  *ssl_cmd_SSLEngine(cmd_parms *, char *, int);
 const char  *ssl_cmd_SSLCipherSuite(cmd_parms *, SSLDirConfigRec *, char *);
+const char  *ssl_cmd_SSLECDHCurve(cmd_parms *, char *, char *);
 const char  *ssl_cmd_SSLHonorCipherOrder(cmd_parms *, char *, int);
 const char  *ssl_cmd_SSLCertificateFile(cmd_parms *, char *, char *);
 const char  *ssl_cmd_SSLCertificateKeyFile(cmd_parms *, char *, char *);
diff --git a/usr.sbin/httpd/src/modules/ssl/ssl_engine_config.c b/usr.sbin/httpd/src/modules/ssl/ssl_engine_config.c
index f7455783b6a..775837a1e89 100644
--- a/usr.sbin/httpd/src/modules/ssl/ssl_engine_config.c
+++ b/usr.sbin/httpd/src/modules/ssl/ssl_engine_config.c
@@ -196,8 +196,9 @@ void *ssl_config_server_create(pool *p, server_rec *s)
     sc->szCertificateChain     = NULL;
     sc->szLogFile              = NULL;
     sc->szCipherSuite          = NULL;
-    sc->nLogLevel              = SSL_LOG_NONE;
+    sc->nECDHCurve             = NID_X9_62_prime256v1;
     sc->bHonorCipherOrder      = UNSET;
+    sc->nLogLevel              = SSL_LOG_NONE;
     sc->nVerifyDepth           = UNSET;
     sc->nVerifyClient          = SSL_CVERIFY_UNSET;
     sc->nSessionCacheTimeout   = UNSET;
@@ -253,6 +254,7 @@ void *ssl_config_server_merge(pool *p, void *basev, void *addv)
     cfgMergeString(szCertificateChain);
     cfgMergeString(szLogFile);
     cfgMergeString(szCipherSuite);
+    cfgMerge(nECDHCurve, NID_X9_62_prime256v1);
     cfgMergeBool(bHonorCipherOrder);
     cfgMerge(nLogLevel, SSL_LOG_NONE);
     cfgMergeInt(nVerifyDepth);
@@ -544,6 +546,25 @@ const char *ssl_cmd_SSLCipherSuite(
     return NULL;
 }
 
+const char *ssl_cmd_SSLECDHCurve(
+    cmd_parms *cmd, char *struct_ptr, char *arg)
+{
+    SSLSrvConfigRec *sc = mySrvConfig(cmd->server);
+
+    if (strcEQ(arg, "none")) {
+        sc->nECDHCurve = 0;
+        return NULL;
+    }
+
+    sc->nECDHCurve = OBJ_sn2nid((const char *)arg);
+    if (sc->nECDHCurve == 0) {
+        return ap_pstrcat(cmd->pool, "SSLECDHCurve: unknown named curve '",
+                          arg, "'", NULL);
+    }
+
+    return NULL;
+}
+
 const char *ssl_cmd_SSLHonorCipherOrder(
      cmd_parms *cmd, char *struct_ptr, int flag)
 {
diff --git a/usr.sbin/httpd/src/modules/ssl/ssl_engine_init.c b/usr.sbin/httpd/src/modules/ssl/ssl_engine_init.c
index eb95d778f79..67930cf4f1b 100644
--- a/usr.sbin/httpd/src/modules/ssl/ssl_engine_init.c
+++ b/usr.sbin/httpd/src/modules/ssl/ssl_engine_init.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_engine_init.c,v 1.30 2013/07/16 11:32:05 jsing Exp $ */
+/* $OpenBSD: ssl_engine_init.c,v 1.31 2013/07/16 13:02:16 jsing Exp $ */
 
 /*                      _             _
 **  _ __ ___   ___   __| |    ___ ___| |  mod_ssl
@@ -530,6 +530,7 @@ void ssl_init_ConfigureServer(server_rec *s, pool *p, SSLSrvConfigRec *sc)
     char *cpVHostID;
     EVP_PKEY *pKey;
     SSL_CTX *ctx;
+    EC_KEY *ecdhKey;
     STACK_OF(X509_NAME) *skCAList;
     ssl_asn1_t *asn1;
     unsigned char *ucp;
@@ -642,6 +643,22 @@ void ssl_init_ConfigureServer(server_rec *s, pool *p, SSLSrvConfigRec *sc)
     }
 
     /*
+     *  Configure ECDH Curve
+     */
+    if (sc->nECDHCurve > 0) {
+        ecdhKey = EC_KEY_new_by_curve_name(sc->nECDHCurve);
+        if (ecdhKey == NULL) {
+            ssl_log(s, SSL_LOG_ERROR|SSL_ADD_SSLERR,
+                    "Init: (%s) Failed to create new EC key using named curve",
+                    cpVHostID);
+            ssl_die();
+        }
+        SSL_CTX_set_tmp_ecdh(ctx, ecdhKey);
+        SSL_CTX_set_options(ctx, SSL_OP_SINGLE_ECDH_USE);
+        EC_KEY_free(ecdhKey);
+    }
+
+    /*
      * Configure Client Authentication details
      */
     if (sc->szCACertificateFile != NULL || sc->szCACertificatePath != NULL) {