lfs: implement HTTP routes (#6035)

* Bootstrap with GORM

* Fix lint error

* Set conn max lifetime to one minute

* Fallback to use gorm v1

* Define HTTP routes

* Finish authentication

* Save token updated

* Add docstring

* Finish authorization

* serveBatch rundown

* Define types in lfsutil

* Finish Batch

* authutil

* Finish basic

* Formalize response error

* Fix lint errors

* authutil: add tests

* dbutil: add tests

* lfsutil: add tests

* strutil: add tests

* Formalize 401 response

internal/authutil/basic_test.go

@@ -0,0 +1,72 @@
+// Copyright 2020 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package authutil
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDecodeBasic(t *testing.T) {
+	tests := []struct {
+		name        string
+		header      http.Header
+		expUsername string
+		expPassword string
+	}{
+		{
+			name: "no header",
+		},
+		{
+			name: "no authorization",
+			header: http.Header{
+				"Content-Type": []string{"text/plain"},
+			},
+		},
+		{
+			name: "malformed value",
+			header: http.Header{
+				"Authorization": []string{"Basic"},
+			},
+		},
+		{
+			name: "not basic",
+			header: http.Header{
+				"Authorization": []string{"Digest dummy"},
+			},
+		},
+		{
+			name: "bad encoding",
+			header: http.Header{
+				"Authorization": []string{"Basic not_base64"},
+			},
+		},
+
+		{
+			name: "only has username",
+			header: http.Header{
+				"Authorization": []string{"Basic dXNlcm5hbWU="},
+			},
+			expUsername: "username",
+		},
+		{
+			name: "has username and password",
+			header: http.Header{
+				"Authorization": []string{"Basic dXNlcm5hbWU6cGFzc3dvcmQ="},
+			},
+			expUsername: "username",
+			expPassword: "password",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			username, password := DecodeBasic(test.header)
+			assert.Equal(t, test.expUsername, username)
+			assert.Equal(t, test.expPassword, password)
+		})
+	}
+}