add ecc support

lets-encrypt/letsencrypt.conf

@@ -3,3 +3,4 @@ ACCOUNT_KEY="letsencrypt-account.key"
 DOMAIN_KEY="example.com.key"
 DOMAIN_DIR="/var/www/example.com"
 DOMAINS="DNS:example.com,DNS:www.example.com"
+#ECC=TRUE

lets-encrypt/letsencrypt.sh

@@ -25,7 +25,11 @@ fi
 
 if [ ! -f "$DOMAIN_KEY" ];then
     echo "Generate domain key..."
-    openssl genrsa 2048 > $DOMAIN_KEY
+    if [ $ECC = "TRUE" ];then
+        openssl ecparam -genkey -name secp256r1 | openssl ec -out $DOMAIN_KEY
+    else
+        openssl genrsa 2048 > $DOMAIN_KEY
+    fi
 fi
 
 echo "Generate CSR...$DOAMIN_CSR"