diff --git a/const.go b/const.go
index 8635486..a3a73ff 100644
--- a/const.go
+++ b/const.go
@@ -125,6 +125,24 @@ const (
 	SSLVERSION_TLSv1   = C.CURL_SSLVERSION_TLSv1
 	SSLVERSION_SSLv2   = C.CURL_SSLVERSION_SSLv2
 	SSLVERSION_SSLv3   = C.CURL_SSLVERSION_SSLv3
+	SSLVERSION_TLSv1_0 = C.CURL_SSLVERSION_TLSv1_0 /* TLSv1.0 (Added in 7.34.0) */
+	SSLVERSION_TLSv1_1 = C.CURL_SSLVERSION_TLSv1_1 /* TLSv1.1 (Added in 7.34.0) */
+	SSLVERSION_TLSv1_2 = C.CURL_SSLVERSION_TLSv1_2 /* TLSv1.2 (Added in 7.34.0) */
+	//SSLVERSION_TLSv1_3 = C.CURL_SSLVERSION_TLSv1_3 /* TLSv1.3 (Added in 7.52.0) */
+)
+
+// for easy.Setopt(OPT_HTTPAUTH, flag)
+const (
+	AUTH_NONE      = C.CURLAUTH_NONE
+	AUTH_BASIC     = C.CURLAUTH_BASIC
+	AUTH_DIGEST    = C.CURLAUTH_DIGEST
+	AUTH_NEGOTIATE = C.CURLAUTH_NEGOTIATE
+	AUTH_NTLM      = C.CURLAUTH_NTLM
+	AUTH_DIGEST_IE = C.CURLAUTH_DIGEST_IE
+	AUTH_NTLM_WB   = C.CURLAUTH_NTLM_WB
+	AUTH_ONLY      = C.CURLAUTH_ONLY
+	AUTH_ANY       = C.CURLAUTH_ANY
+	AUTH_ANYSAFE   = C.CURLAUTH_ANYSAFE
 )
 
 // for easy.Setopt(OPT_TIMECONDITION, flag)