Add Authenticator interface and Digest auth support

basicAuth.go

@@ -0,0 +1,33 @@
+package gowebdav
+
+import (
+	"encoding/base64"
+)
+
+// BasicAuth structure holds our credentials
+type BasicAuth struct {
+	user string
+	pw   string
+}
+
+// Type identifies the BasicAuthenticator
+func (b *BasicAuth) Type() string {
+	return "BasicAuth"
+}
+
+// User holds the BasicAuth username
+func (b *BasicAuth) User() string {
+	return b.user
+}
+
+// Pass holds the BasicAuth password
+func (b *BasicAuth) Pass() string {
+	return b.pw
+}
+
+// Authorize the current request
+func (b *BasicAuth) Authorize(c *Client, method string, path string) {
+	a := b.user + ":" + b.pw
+	auth := "Basic " + base64.StdEncoding.EncodeToString([]byte(a))
+	c.headers.Set("Authorization", auth)
+}