Integrate new auth interface

internal/auth/local.go

@@ -0,0 +1,35 @@
+package auth
+
+import (
+	"fmt"
+	"net/http"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+type LocalAuthenticator struct {
+	auth *Authentication
+}
+
+var _ Authenticator = (*LocalAuthenticator)(nil)
+
+func (la *LocalAuthenticator) Init(auth *Authentication, _ interface{}) error {
+	la.auth = auth
+	return nil
+}
+
+func (la *LocalAuthenticator) CanLogin(user *User, rw http.ResponseWriter, r *http.Request) bool {
+	return user != nil && user.AuthSource == AuthViaLocalPassword
+}
+
+func (la *LocalAuthenticator) Login(user *User, rw http.ResponseWriter, r *http.Request) (*User, error) {
+	if e := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(r.FormValue("password"))); e != nil {
+		return nil, fmt.Errorf("user '%s' provided the wrong password (%w)", user.Username, e)
+	}
+
+	return user, nil
+}
+
+func (la *LocalAuthenticator) Auth(rw http.ResponseWriter, r *http.Request) (*User, error) {
+	return la.auth.AuthViaSession(rw, r)
+}