add metadata

pkg/auth/auth.go

@@ -0,0 +1,40 @@
+package auth
+
+// Authenticator is an interface for user authentication.
+type Authenticator interface {
+	Authenticate(user, password string) bool
+}
+
+// LocalAuthenticator is an Authenticator that authenticates client by local key-value pairs.
+type LocalAuthenticator struct {
+	kvs map[string]string
+}
+
+// NewLocalAuthenticator creates an Authenticator that authenticates client by local infos.
+func NewLocalAuthenticator(kvs map[string]string) *LocalAuthenticator {
+	if kvs == nil {
+		kvs = make(map[string]string)
+	}
+	return &LocalAuthenticator{
+		kvs: kvs,
+	}
+}
+
+// Authenticate checks the validity of the provided user-password pair.
+func (au *LocalAuthenticator) Authenticate(user, password string) bool {
+	if au == nil {
+		return true
+	}
+
+	if len(au.kvs) == 0 {
+		return true
+	}
+
+	v, ok := au.kvs[user]
+	return ok && (v == "" || password == v)
+}
+
+// Add adds a key-value pair to the Authenticator.
+func (au *LocalAuthenticator) Add(k, v string) {
+	au.kvs[k] = v
+}