Integrate OAuth2 Provider (#5378)

Gopkg.lock

@@ -962,11 +962,13 @@
   revision = "2c050d2dae5345c417db301f11fda6fbf5ad0f0a"
 
 [[projects]]
-  digest = "1:c3d6b9e2cf3936ba9927da2e8858651aad69890b9dd3349f1316b4003b25d7a3"
+  digest = "1:590035a7bbea1c037c2e6d51f81ee09857480c3c21f1f77397d9802f10507c06"
   name = "golang.org/x/crypto"
   packages = [
     "acme",
     "acme/autocert",
+    "bcrypt",
+    "blowfish",
     "cast5",
     "curve25519",
     "ed25519",
@@ -1315,6 +1317,7 @@
     "github.com/urfave/cli",
     "github.com/yohcop/openid-go",
     "golang.org/x/crypto/acme/autocert",
+    "golang.org/x/crypto/bcrypt",
     "golang.org/x/crypto/pbkdf2",
     "golang.org/x/crypto/ssh",
     "golang.org/x/net/html",

cmd/generate.go

@@ -63,7 +63,7 @@ func runGenerateInternalToken(c *cli.Context) error {
 }
 
 func runGenerateLfsJwtSecret(c *cli.Context) error {
-	JWTSecretBase64, err := generate.NewLfsJwtSecret()
+	JWTSecretBase64, err := generate.NewJwtSecret()
 	if err != nil {
 		return err
 	}

custom/conf/app.ini.sample

@@ -654,6 +654,16 @@ DEFAULT_PAGING_NUM = 30
 ; Default and maximum number of items per page for git trees api
 DEFAULT_GIT_TREES_PER_PAGE = 1000
 
+[oauth2]
+; Enables OAuth2 provider
+ENABLED = true
+; Lifetime of an OAuth2 access token in seconds
+ACCESS_TOKEN_EXPIRATION_TIME=3600
+; Lifetime of an OAuth2 access token in hours
+REFRESH_TOKEN_EXPIRATION_TIME=730
+; OAuth2 authentication secret for access and refresh tokens, change this a unique string.
+JWT_SECRET=Bk0yK7Y9g_p56v86KaHqjSbxvNvu3SbKoOdOt2ZcXvU
+
 [i18n]
 LANGS = en-US,zh-CN,zh-HK,zh-TW,de-DE,fr-FR,nl-NL,lv-LV,ru-RU,uk-UA,ja-JP,es-ES,pt-BR,pl-PL,bg-BG,it-IT,fi-FI,tr-TR,cs-CZ,sr-SP,sv-SE,ko-KR
 NAMES = English,简体中文,繁體中文（香港）,繁體中文（台灣）,Deutsch,français,Nederlands,latviešu,русский,Українська,日本語,español,português do Brasil,polski,български,italiano,suomi,Türkçe,čeština,српски,svenska,한국어

docs/content/doc/advanced/config-cheat-sheet.en-us.md

@@ -345,6 +345,13 @@ Values containing `#` or `;` must be quoted using `` ` `` or `"""`.
 - `DEFAULT_PAGING_NUM`: **30**: Default paging number of api.
 - `DEFAULT_GIT_TREES_PER_PAGE`: **1000**: Default and maximum number of items per page for git trees api.
 
+## OAuth2 (`oauth2`)
+
+- `ENABLED`: **true**: Enables OAuth2 provider.
+- `ACCESS_TOKEN_EXPIRATION_TIME`: **3600**: Lifetime of an OAuth2 access token in seconds
+- `REFRESH_TOKEN_EXPIRATION_TIME`: **730**: Lifetime of an OAuth2 access token in hours
+- `JWT_SECRET`: **\<empty\>**: OAuth2 authentication secret for access and refresh tokens, change this a unique string.
+
 ## i18n (`i18n`)
 
 - `LANGS`: **en-US,zh-CN,zh-HK,zh-TW,de-DE,fr-FR,nl-NL,lv-LV,ru-RU,ja-JP,es-ES,pt-BR,pl-PL,bg-BG,it-IT,fi-FI,tr-TR,cs-CZ,sr-SP,sv-SE,ko-KR**: List of locales shown in language selector

integrations/oauth_test.go

@@ -0,0 +1,138 @@
+// Copyright 2019 The Gitea 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 integrations
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const defaultAuthorize = "/login/oauth/authorize?client_id=da7da3ba-9a13-4167-856f-3899de0b0138&redirect_uri=a&response_type=code&state=thestate"
+
+func TestNoClientID(t *testing.T) {
+	prepareTestEnv(t)
+	req := NewRequest(t, "GET", "/login/oauth/authorize")
+	ctx := loginUser(t, "user2")
+	ctx.MakeRequest(t, req, 400)
+}
+
+func TestLoginRedirect(t *testing.T) {
+	prepareTestEnv(t)
+	req := NewRequest(t, "GET", "/login/oauth/authorize")
+	assert.Contains(t, MakeRequest(t, req, 302).Body.String(), "/user/login")
+}
+
+func TestShowAuthorize(t *testing.T) {
+	prepareTestEnv(t)
+	req := NewRequest(t, "GET", defaultAuthorize)
+	ctx := loginUser(t, "user4")
+	resp := ctx.MakeRequest(t, req, 200)
+
+	htmlDoc := NewHTMLParser(t, resp.Body)
+	htmlDoc.AssertElement(t, "#authorize-app", true)
+	htmlDoc.GetCSRF()
+}
+
+func TestRedirectWithExistingGrant(t *testing.T) {
+	prepareTestEnv(t)
+	req := NewRequest(t, "GET", defaultAuthorize)
+	ctx := loginUser(t, "user1")
+	resp := ctx.MakeRequest(t, req, 302)
+	u, err := resp.Result().Location()
+	assert.NoError(t, err)
+	assert.Equal(t, "thestate", u.Query().Get("state"))
+	assert.Truef(t, len(u.Query().Get("code")) > 30, "authorization code '%s' should be longer then 30", u.Query().Get("code"))
+}
+
+func TestAccessTokenExchange(t *testing.T) {
+	prepareTestEnv(t)
+	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
+		"grant_type":    "authorization_code",
+		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
+		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
+		"redirect_uri":  "a",
+		"code":          "authcode",
+		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt", // test PKCE additionally
+	})
+	resp := MakeRequest(t, req, 200)
+	type response struct {
+		AccessToken  string `json:"access_token"`
+		TokenType    string `json:"token_type"`
+		ExpiresIn    int64  `json:"expires_in"`
+		RefreshToken string `json:"refresh_token"`
+	}
+	parsed := new(response)
+	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsed))
+	assert.True(t, len(parsed.AccessToken) > 10)
+	assert.True(t, len(parsed.RefreshToken) > 10)
+}
+
+func TestAccessTokenExchangeWithoutPKCE(t *testing.T) {
+	prepareTestEnv(t)
+	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
+		"grant_type":    "authorization_code",
+		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
+		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
+		"redirect_uri":  "a",
+		"code":          "authcode",
+	})
+	MakeRequest(t, req, 400)
+}
+
+func TestAccessTokenExchangeWithInvalidCredentials(t *testing.T) {
+	prepareTestEnv(t)
+	// invalid client id
+	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
+		"grant_type":    "authorization_code",
+		"client_id":     "???",
+		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
+		"redirect_uri":  "a",
+		"code":          "authcode",
+		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt", // test PKCE additionally
+	})
+	MakeRequest(t, req, 400)
+	// invalid client secret
+	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
+		"grant_type":    "authorization_code",
+		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
+		"client_secret": "???",
+		"redirect_uri":  "a",
+		"code":          "authcode",
+		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt", // test PKCE additionally
+	})
+	MakeRequest(t, req, 400)
+	// invalid redirect uri
+	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
+		"grant_type":    "authorization_code",
+		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
+		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
+		"redirect_uri":  "???",
+		"code":          "authcode",
+		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt", // test PKCE additionally
+	})
+	MakeRequest(t, req, 400)
+	// invalid authorization code
+	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
+		"grant_type":    "authorization_code",
+		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
+		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
+		"redirect_uri":  "a",
+		"code":          "???",
+		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt", // test PKCE additionally
+	})
+	MakeRequest(t, req, 400)
+	// invalid grant_type
+	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
+		"grant_type":    "???",
+		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
+		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
+		"redirect_uri":  "a",
+		"code":          "authcode",
+		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt", // test PKCE additionally
+	})
+	MakeRequest(t, req, 400)
+}

models/error.go

@@ -1398,3 +1398,42 @@ func IsErrReviewNotExist(err error) bool {
 func (err ErrReviewNotExist) Error() string {
 	return fmt.Sprintf("review does not exist [id: %d]", err.ID)
 }
+
+//  ________      _____          __  .__
+//  \_____  \    /  _  \  __ ___/  |_|  |__
+//   /   |   \  /  /_\  \|  |  \   __\  |  \
+//  /    |    \/    |    \  |  /|  | |   Y  \
+//  \_______  /\____|__  /____/ |__| |___|  /
+//          \/         \/                 \/
+
+// ErrOAuthClientIDInvalid will be thrown if client id cannot be found
+type ErrOAuthClientIDInvalid struct {
+	ClientID string
+}
+
+// IsErrOauthClientIDInvalid checks if an error is a ErrReviewNotExist.
+func IsErrOauthClientIDInvalid(err error) bool {
+	_, ok := err.(ErrOAuthClientIDInvalid)
+	return ok
+}
+
+// Error returns the error message
+func (err ErrOAuthClientIDInvalid) Error() string {
+	return fmt.Sprintf("Client ID invalid [Client ID: %s]", err.ClientID)
+}
+
+// ErrOAuthApplicationNotFound will be thrown if id cannot be found
+type ErrOAuthApplicationNotFound struct {
+	ID int64
+}
+
+// IsErrOAuthApplicationNotFound checks if an error is a ErrReviewNotExist.
+func IsErrOAuthApplicationNotFound(err error) bool {
+	_, ok := err.(ErrOAuthApplicationNotFound)
+	return ok
+}
+
+// Error returns the error message
+func (err ErrOAuthApplicationNotFound) Error() string {
+	return fmt.Sprintf("OAuth application not found [ID: %d]", err.ID)
+}

models/fixtures/oauth2_application.yml

@@ -0,0 +1,9 @@
+-
+  id: 1
+  uid: 1
+  name: "Test"
+  client_id: "da7da3ba-9a13-4167-856f-3899de0b0138"
+  client_secret: "$2a$10$UYRgUSgekzBp6hYe8pAdc.cgB4Gn06QRKsORUnIYTYQADs.YR/uvi" # bcrypt of "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=
+  redirect_uris: '["a"]'
+  created_unix: 1546869730
+  updated_unix: 1546869730

models/fixtures/oauth2_authorization_code.yml

@@ -0,0 +1,8 @@
+- id: 1
+  grant_id: 1
+  code: "authcode"
+  code_challenge: "CjvyTLSdR47G5zYenDA-eDWW4lRrO8yvjcWwbD_deOg" # Code Verifier: N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt
+  code_challenge_method: "S256"
+  redirect_uri: "a"
+  valid_until: 3546869730
+

models/fixtures/oauth2_grant.yml

@@ -0,0 +1,6 @@
+- id: 1
+  user_id: 1
+  application_id: 1
+  counter: 1
+  created_unix: 1546869730
+  updated_unix: 1546869730

models/models.go

@@ -125,6 +125,9 @@ func init() {
 		new(U2FRegistration),
 		new(TeamUnit),
 		new(Review),
+		new(OAuth2Application),
+		new(OAuth2AuthorizationCode),
+		new(OAuth2Grant),
 	)
 
 	gonicNames := []string{"SSL", "UID"}

models/oauth2_application.go

@@ -0,0 +1,457 @@
+// Copyright 2019 The Gitea 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 models
+
+import (
+	"crypto/sha256"
+	"encoding/base64"
+	"fmt"
+	"net/url"
+	"time"
+
+	"github.com/go-xorm/xorm"
+	uuid "github.com/satori/go.uuid"
+
+	"code.gitea.io/gitea/modules/secret"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/Unknwon/com"
+	"github.com/dgrijalva/jwt-go"
+	"golang.org/x/crypto/bcrypt"
+)
+
+// OAuth2Application represents an OAuth2 client (RFC 6749)
+type OAuth2Application struct {
+	ID   int64 `xorm:"pk autoincr"`
+	UID  int64 `xorm:"INDEX"`
+	User *User `xorm:"-"`
+
+	Name string
+
+	ClientID     string `xorm:"unique"`
+	ClientSecret string
+
+	RedirectURIs []string `xorm:"redirect_uris JSON TEXT"`
+
+	CreatedUnix util.TimeStamp `xorm:"INDEX created"`
+	UpdatedUnix util.TimeStamp `xorm:"INDEX updated"`
+}
+
+// TableName sets the table name to `oauth2_application`
+func (app *OAuth2Application) TableName() string {
+	return "oauth2_application"
+}
+
+// PrimaryRedirectURI returns the first redirect uri or an empty string if empty
+func (app *OAuth2Application) PrimaryRedirectURI() string {
+	if len(app.RedirectURIs) == 0 {
+		return ""
+	}
+	return app.RedirectURIs[0]
+}
+
+// LoadUser will load User by UID
+func (app *OAuth2Application) LoadUser() (err error) {
+	if app.User == nil {
+		app.User, err = GetUserByID(app.UID)
+	}
+	return
+}
+
+// ContainsRedirectURI checks if redirectURI is allowed for app
+func (app *OAuth2Application) ContainsRedirectURI(redirectURI string) bool {
+	return com.IsSliceContainsStr(app.RedirectURIs, redirectURI)
+}
+
+// GenerateClientSecret will generate the client secret and returns the plaintext and saves the hash at the database
+func (app *OAuth2Application) GenerateClientSecret() (string, error) {
+	clientSecret, err := secret.New()
+	if err != nil {
+		return "", err
+	}
+	hashedSecret, err := bcrypt.GenerateFromPassword([]byte(clientSecret), bcrypt.DefaultCost)
+	if err != nil {
+		return "", err
+	}
+	app.ClientSecret = string(hashedSecret)
+	if _, err := x.ID(app.ID).Cols("client_secret").Update(app); err != nil {
+		return "", err
+	}
+	return clientSecret, nil
+}
+
+// ValidateClientSecret validates the given secret by the hash saved in database
+func (app *OAuth2Application) ValidateClientSecret(secret []byte) bool {
+	return bcrypt.CompareHashAndPassword([]byte(app.ClientSecret), secret) == nil
+}
+
+// GetGrantByUserID returns a OAuth2Grant by its user and application ID
+func (app *OAuth2Application) GetGrantByUserID(userID int64) (*OAuth2Grant, error) {
+	return app.getGrantByUserID(x, userID)
+}
+
+func (app *OAuth2Application) getGrantByUserID(e Engine, userID int64) (grant *OAuth2Grant, err error) {
+	grant = new(OAuth2Grant)
+	if has, err := e.Where("user_id = ? AND application_id = ?", userID, app.ID).Get(grant); err != nil {
+		return nil, err
+	} else if !has {
+		return nil, nil
+	}
+	return grant, nil
+}
+
+// CreateGrant generates a grant for an user
+func (app *OAuth2Application) CreateGrant(userID int64) (*OAuth2Grant, error) {
+	return app.createGrant(x, userID)
+}
+
+func (app *OAuth2Application) createGrant(e Engine, userID int64) (*OAuth2Grant, error) {
+	grant := &OAuth2Grant{
+		ApplicationID: app.ID,
+		UserID:        userID,
+	}
+	_, err := e.Insert(grant)
+	if err != nil {
+		return nil, err
+	}
+	return grant, nil
+}
+
+// GetOAuth2ApplicationByClientID returns the oauth2 application with the given client_id. Returns an error if not found.
+func GetOAuth2ApplicationByClientID(clientID string) (app *OAuth2Application, err error) {
+	return getOAuth2ApplicationByClientID(x, clientID)
+}
+
+func getOAuth2ApplicationByClientID(e Engine, clientID string) (app *OAuth2Application, err error) {
+	app = new(OAuth2Application)
+	has, err := e.Where("client_id = ?", clientID).Get(app)
+	if !has {
+		return nil, ErrOAuthClientIDInvalid{ClientID: clientID}
+	}
+	return
+}
+
+// GetOAuth2ApplicationByID returns the oauth2 application with the given id. Returns an error if not found.
+func GetOAuth2ApplicationByID(id int64) (app *OAuth2Application, err error) {
+	return getOAuth2ApplicationByID(x, id)
+}
+
+func getOAuth2ApplicationByID(e Engine, id int64) (app *OAuth2Application, err error) {
+	app = new(OAuth2Application)
+	has, err := e.ID(id).Get(app)
+	if !has {
+		return nil, ErrOAuthApplicationNotFound{ID: id}
+	}
+	return app, nil
+}
+
+// GetOAuth2ApplicationsByUserID returns all oauth2 applications owned by the user
+func GetOAuth2ApplicationsByUserID(userID int64) (apps []*OAuth2Application, err error) {
+	return getOAuth2ApplicationsByUserID(x, userID)
+}
+
+func getOAuth2ApplicationsByUserID(e Engine, userID int64) (apps []*OAuth2Application, err error) {
+	apps = make([]*OAuth2Application, 0)
+	err = e.Where("uid = ?", userID).Find(&apps)
+	return
+}
+
+// CreateOAuth2ApplicationOptions holds options to create an oauth2 application
+type CreateOAuth2ApplicationOptions struct {
+	Name         string
+	UserID       int64
+	RedirectURIs []string
+}
+
+// CreateOAuth2Application inserts a new oauth2 application
+func CreateOAuth2Application(opts CreateOAuth2ApplicationOptions) (*OAuth2Application, error) {
+	return createOAuth2Application(x, opts)
+}
+
+func createOAuth2Application(e Engine, opts CreateOAuth2ApplicationOptions) (*OAuth2Application, error) {
+	clientID := uuid.NewV4().String()
+	app := &OAuth2Application{
+		UID:          opts.UserID,
+		Name:         opts.Name,
+		ClientID:     clientID,
+		RedirectURIs: opts.RedirectURIs,
+	}
+	if _, err := e.Insert(app); err != nil {
+		return nil, err
+	}
+	return app, nil
+}
+
+// UpdateOAuth2ApplicationOptions holds options to update an oauth2 application
+type UpdateOAuth2ApplicationOptions struct {
+	ID           int64
+	Name         string
+	UserID       int64
+	RedirectURIs []string
+}
+
+// UpdateOAuth2Application updates an oauth2 application
+func UpdateOAuth2Application(opts UpdateOAuth2ApplicationOptions) error {
+	return updateOAuth2Application(x, opts)
+}
+
+func updateOAuth2Application(e Engine, opts UpdateOAuth2ApplicationOptions) error {
+	app := &OAuth2Application{
+		ID:           opts.ID,
+		UID:          opts.UserID,
+		Name:         opts.Name,
+		RedirectURIs: opts.RedirectURIs,
+	}
+	if _, err := e.ID(opts.ID).Update(app); err != nil {
+		return err
+	}
+	return nil
+}
+
+func deleteOAuth2Application(sess *xorm.Session, id, userid int64) error {
+	if deleted, err := sess.Delete(&OAuth2Application{ID: id, UID: userid}); err != nil {
+		return err
+	} else if deleted == 0 {
+		return fmt.Errorf("cannot find oauth2 application")
+	}
+	codes := make([]*OAuth2AuthorizationCode, 0)
+	// delete correlating auth codes
+	if err := sess.Join("INNER", "oauth2_grant",
+		"oauth2_authorization_code.grant_id = oauth2_grant.id AND oauth2_grant.application_id = ?", id).Find(&codes); err != nil {
+		return err
+	}
+	codeIDs := make([]int64, 0)
+	for _, grant := range codes {
+		codeIDs = append(codeIDs, grant.ID)
+	}
+
+	if _, err := sess.In("id", codeIDs).Delete(new(OAuth2AuthorizationCode)); err != nil {
+		return err
+	}
+
+	if _, err := sess.Where("application_id = ?", id).Delete(new(OAuth2Grant)); err != nil {
+		return err
+	}
+	return nil
+}
+
+// DeleteOAuth2Application deletes the application with the given id and the grants and auth codes related to it. It checks if the userid was the creator of the app.
+func DeleteOAuth2Application(id, userid int64) error {
+	sess := x.NewSession()
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+	if err := deleteOAuth2Application(sess, id, userid); err != nil {
+		return err
+	}
+	return sess.Commit()
+}
+
+//////////////////////////////////////////////////////
+
+// OAuth2AuthorizationCode is a code to obtain an access token in combination with the client secret once. It has a limited lifetime.
+type OAuth2AuthorizationCode struct {
+	ID                  int64        `xorm:"pk autoincr"`
+	Grant               *OAuth2Grant `xorm:"-"`
+	GrantID             int64
+	Code                string `xorm:"INDEX unique"`
+	CodeChallenge       string
+	CodeChallengeMethod string
+	RedirectURI         string
+	ValidUntil          util.TimeStamp `xorm:"index"`
+}
+
+// TableName sets the table name to `oauth2_authorization_code`
+func (code *OAuth2AuthorizationCode) TableName() string {
+	return "oauth2_authorization_code"
+}
+
+// GenerateRedirectURI generates a redirect URI for a successful authorization request. State will be used if not empty.
+func (code *OAuth2AuthorizationCode) GenerateRedirectURI(state string) (redirect *url.URL, err error) {
+	if redirect, err = url.Parse(code.RedirectURI); err != nil {
+		return
+	}
+	q := redirect.Query()
+	if state != "" {
+		q.Set("state", state)
+	}
+	q.Set("code", code.Code)
+	redirect.RawQuery = q.Encode()
+	return
+}
+
+// Invalidate deletes the auth code from the database to invalidate this code
+func (code *OAuth2AuthorizationCode) Invalidate() error {
+	return code.invalidate(x)
+}
+
+func (code *OAuth2AuthorizationCode) invalidate(e Engine) error {
+	_, err := e.Delete(code)
+	return err
+}
+
+// ValidateCodeChallenge validates the given verifier against the saved code challenge. This is part of the PKCE implementation.
+func (code *OAuth2AuthorizationCode) ValidateCodeChallenge(verifier string) bool {
+	return code.validateCodeChallenge(x, verifier)
+}
+
+func (code *OAuth2AuthorizationCode) validateCodeChallenge(e Engine, verifier string) bool {
+	switch code.CodeChallengeMethod {
+	case "S256":
+		// base64url(SHA256(verifier)) see https://tools.ietf.org/html/rfc7636#section-4.6
+		h := sha256.Sum256([]byte(verifier))
+		hashedVerifier := base64.RawURLEncoding.EncodeToString(h[:])
+		return hashedVerifier == code.CodeChallenge
+	case "plain":
+		return verifier == code.CodeChallenge
+	case "":
+		return true
+	default:
+		// unsupported method -> return false
+		return false
+	}
+}
+
+// GetOAuth2AuthorizationByCode returns an authorization by its code
+func GetOAuth2AuthorizationByCode(code string) (*OAuth2AuthorizationCode, error) {
+	return getOAuth2AuthorizationByCode(x, code)
+}
+
+func getOAuth2AuthorizationByCode(e Engine, code string) (auth *OAuth2AuthorizationCode, err error) {
+	auth = new(OAuth2AuthorizationCode)
+	if has, err := e.Where("code = ?", code).Get(auth); err != nil {
+		return nil, err
+	} else if !has {
+		return nil, nil
+	}
+	auth.Grant = new(OAuth2Grant)
+	if has, err := e.ID(auth.GrantID).Get(auth.Grant); err != nil {
+		return nil, err
+	} else if !has {
+		return nil, nil
+	}
+	return auth, nil
+}
+
+//////////////////////////////////////////////////////
+
+// OAuth2Grant represents the permission of an user for a specifc application to access resources
+type OAuth2Grant struct {
+	ID            int64          `xorm:"pk autoincr"`
+	UserID        int64          `xorm:"INDEX unique(user_application)"`
+	ApplicationID int64          `xorm:"INDEX unique(user_application)"`
+	Counter       int64          `xorm:"NOT NULL DEFAULT 1"`
+	CreatedUnix   util.TimeStamp `xorm:"created"`
+	UpdatedUnix   util.TimeStamp `xorm:"updated"`
+}
+
+// TableName sets the table name to `oauth2_grant`
+func (grant *OAuth2Grant) TableName() string {
+	return "oauth2_grant"
+}
+
+// GenerateNewAuthorizationCode generates a new authorization code for a grant and saves it to the databse
+func (grant *OAuth2Grant) GenerateNewAuthorizationCode(redirectURI, codeChallenge, codeChallengeMethod string) (*OAuth2AuthorizationCode, error) {
+	return grant.generateNewAuthorizationCode(x, redirectURI, codeChallenge, codeChallengeMethod)
+}
+
+func (grant *OAuth2Grant) generateNewAuthorizationCode(e Engine, redirectURI, codeChallenge, codeChallengeMethod string) (code *OAuth2AuthorizationCode, err error) {
+	var codeSecret string
+	if codeSecret, err = secret.New(); err != nil {
+		return &OAuth2AuthorizationCode{}, err
+	}
+	code = &OAuth2AuthorizationCode{
+		Grant:               grant,
+		GrantID:             grant.ID,
+		RedirectURI:         redirectURI,
+		Code:                codeSecret,
+		CodeChallenge:       codeChallenge,
+		CodeChallengeMethod: codeChallengeMethod,
+	}
+	if _, err := e.Insert(code); err != nil {
+		return nil, err
+	}
+	return code, nil
+}
+
+// IncreaseCounter increases the counter and updates the grant
+func (grant *OAuth2Grant) IncreaseCounter() error {
+	return grant.increaseCount(x)
+}
+
+func (grant *OAuth2Grant) increaseCount(e Engine) error {
+	_, err := e.ID(grant.ID).Incr("counter").Update(new(OAuth2Grant))
+	if err != nil {
+		return err
+	}
+	updatedGrant, err := getOAuth2GrantByID(e, grant.ID)
+	if err != nil {
+		return err
+	}
+	grant.Counter = updatedGrant.Counter
+	return nil
+}
+
+// GetOAuth2GrantByID returns the grant with the given ID
+func GetOAuth2GrantByID(id int64) (*OAuth2Grant, error) {
+	return getOAuth2GrantByID(x, id)
+}
+
+func getOAuth2GrantByID(e Engine, id int64) (grant *OAuth2Grant, err error) {
+	grant = new(OAuth2Grant)
+	if has, err := e.ID(id).Get(grant); err != nil {
+		return nil, err
+	} else if !has {
+		return nil, nil
+	}
+	return
+}
+
+//////////////////////////////////////////////////////////////
+
+// OAuth2TokenType represents the type of token for an oauth application
+type OAuth2TokenType int
+
+const (
+	// TypeAccessToken is a token with short lifetime to access the api
+	TypeAccessToken OAuth2TokenType = 0
+	// TypeRefreshToken is token with long lifetime to refresh access tokens obtained by the client
+	TypeRefreshToken = iota
+)
+
+// OAuth2Token represents a JWT token used to authenticate a client
+type OAuth2Token struct {
+	GrantID int64           `json:"gnt"`
+	Type    OAuth2TokenType `json:"tt"`
+	Counter int64           `json:"cnt,omitempty"`
+	jwt.StandardClaims
+}
+
+// ParseOAuth2Token parses a singed jwt string
+func ParseOAuth2Token(jwtToken string) (*OAuth2Token, error) {
+	parsedToken, err := jwt.ParseWithClaims(jwtToken, &OAuth2Token{}, func(token *jwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, fmt.Errorf("unexpected signing algo: %v", token.Header["alg"])
+		}
+		return setting.OAuth2.JWTSecretBytes, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	var token *OAuth2Token
+	var ok bool
+	if token, ok = parsedToken.Claims.(*OAuth2Token); !ok || !parsedToken.Valid {
+		return nil, fmt.Errorf("invalid token")
+	}
+	return token, nil
+}
+
+// SignToken signs the token with the JWT secret
+func (token *OAuth2Token) SignToken() (string, error) {
+	token.IssuedAt = time.Now().Unix()
+	jwtToken := jwt.NewWithClaims(jwt.SigningMethodHS512, token)
+	return jwtToken.SignedString(setting.OAuth2.JWTSecretBytes)
+}

models/oauth2_application_test.go

@@ -0,0 +1,209 @@
+// Copyright 2019 The Gitea 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 models
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+//////////////////// Application
+
+func TestOAuth2Application_GenerateClientSecret(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	secret, err := app.GenerateClientSecret()
+	assert.NoError(t, err)
+	assert.True(t, len(secret) > 0)
+	AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1, ClientSecret: app.ClientSecret})
+}
+
+func BenchmarkOAuth2Application_GenerateClientSecret(b *testing.B) {
+	assert.NoError(b, PrepareTestDatabase())
+	app := AssertExistsAndLoadBean(b, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	for i := 0; i < b.N; i++ {
+		_, _ = app.GenerateClientSecret()
+	}
+}
+
+func TestOAuth2Application_ContainsRedirectURI(t *testing.T) {
+	app := &OAuth2Application{
+		RedirectURIs: []string{"a", "b", "c"},
+	}
+	assert.True(t, app.ContainsRedirectURI("a"))
+	assert.True(t, app.ContainsRedirectURI("b"))
+	assert.True(t, app.ContainsRedirectURI("c"))
+	assert.False(t, app.ContainsRedirectURI("d"))
+}
+
+func TestOAuth2Application_ValidateClientSecret(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	secret, err := app.GenerateClientSecret()
+	assert.NoError(t, err)
+	assert.True(t, app.ValidateClientSecret([]byte(secret)))
+	assert.False(t, app.ValidateClientSecret([]byte("fewijfowejgfiowjeoifew")))
+}
+
+func TestGetOAuth2ApplicationByClientID(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	app, err := GetOAuth2ApplicationByClientID("da7da3ba-9a13-4167-856f-3899de0b0138")
+	assert.NoError(t, err)
+	assert.Equal(t, "da7da3ba-9a13-4167-856f-3899de0b0138", app.ClientID)
+
+	app, err = GetOAuth2ApplicationByClientID("invalid client id")
+	assert.Error(t, err)
+	assert.Nil(t, app)
+}
+
+func TestCreateOAuth2Application(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	app, err := CreateOAuth2Application(CreateOAuth2ApplicationOptions{Name: "newapp", UserID: 1})
+	assert.NoError(t, err)
+	assert.Equal(t, "newapp", app.Name)
+	assert.Len(t, app.ClientID, 36)
+	AssertExistsAndLoadBean(t, &OAuth2Application{Name: "newapp"})
+}
+
+func TestOAuth2Application_LoadUser(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	assert.NoError(t, app.LoadUser())
+	assert.NotNil(t, app.User)
+}
+
+func TestOAuth2Application_TableName(t *testing.T) {
+	assert.Equal(t, "oauth2_application", new(OAuth2Application).TableName())
+}
+
+func TestOAuth2Application_GetGrantByUserID(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	grant, err := app.GetGrantByUserID(1)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(1), grant.UserID)
+
+	grant, err = app.GetGrantByUserID(34923458)
+	assert.NoError(t, err)
+	assert.Nil(t, grant)
+}
+
+func TestOAuth2Application_CreateGrant(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	grant, err := app.CreateGrant(2)
+	assert.NoError(t, err)
+	assert.NotNil(t, grant)
+	assert.Equal(t, int64(2), grant.UserID)
+	assert.Equal(t, int64(1), grant.ApplicationID)
+}
+
+//////////////////// Grant
+
+func TestGetOAuth2GrantByID(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	grant, err := GetOAuth2GrantByID(1)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(1), grant.ID)
+
+	grant, err = GetOAuth2GrantByID(34923458)
+	assert.NoError(t, err)
+	assert.Nil(t, grant)
+}
+
+func TestOAuth2Grant_IncreaseCounter(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	grant := AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1, Counter: 1}).(*OAuth2Grant)
+	assert.NoError(t, grant.IncreaseCounter())
+	assert.Equal(t, int64(2), grant.Counter)
+	AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1, Counter: 2})
+}
+
+func TestOAuth2Grant_GenerateNewAuthorizationCode(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	grant := AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1}).(*OAuth2Grant)
+	code, err := grant.GenerateNewAuthorizationCode("https://example2.com/callback", "CjvyTLSdR47G5zYenDA-eDWW4lRrO8yvjcWwbD_deOg", "S256")
+	assert.NoError(t, err)
+	assert.NotNil(t, code)
+	assert.True(t, len(code.Code) > 32) // secret length > 32
+}
+
+func TestOAuth2Grant_TableName(t *testing.T) {
+	assert.Equal(t, "oauth2_grant", new(OAuth2Grant).TableName())
+}
+
+//////////////////// Authorization Code
+
+func TestGetOAuth2AuthorizationByCode(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	code, err := GetOAuth2AuthorizationByCode("authcode")
+	assert.NoError(t, err)
+	assert.NotNil(t, code)
+	assert.Equal(t, "authcode", code.Code)
+	assert.Equal(t, int64(1), code.ID)
+
+	code, err = GetOAuth2AuthorizationByCode("does not exist")
+	assert.NoError(t, err)
+	assert.Nil(t, code)
+}
+
+func TestOAuth2AuthorizationCode_ValidateCodeChallenge(t *testing.T) {
+	// test plain
+	code := &OAuth2AuthorizationCode{
+		CodeChallengeMethod: "plain",
+		CodeChallenge:       "test123",
+	}
+	assert.True(t, code.ValidateCodeChallenge("test123"))
+	assert.False(t, code.ValidateCodeChallenge("ierwgjoergjio"))
+
+	// test S256
+	code = &OAuth2AuthorizationCode{
+		CodeChallengeMethod: "S256",
+		CodeChallenge:       "CjvyTLSdR47G5zYenDA-eDWW4lRrO8yvjcWwbD_deOg",
+	}
+	assert.True(t, code.ValidateCodeChallenge("N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt"))
+	assert.False(t, code.ValidateCodeChallenge("wiogjerogorewngoenrgoiuenorg"))
+
+	// test unknown
+	code = &OAuth2AuthorizationCode{
+		CodeChallengeMethod: "monkey",
+		CodeChallenge:       "foiwgjioriogeiogjerger",
+	}
+	assert.False(t, code.ValidateCodeChallenge("foiwgjioriogeiogjerger"))
+
+	// test no code challenge
+	code = &OAuth2AuthorizationCode{
+		CodeChallengeMethod: "",
+		CodeChallenge:       "foierjiogerogerg",
+	}
+	assert.True(t, code.ValidateCodeChallenge(""))
+}
+
+func TestOAuth2AuthorizationCode_GenerateRedirectURI(t *testing.T) {
+	code := &OAuth2AuthorizationCode{
+		RedirectURI: "https://example.com/callback",
+		Code:        "thecode",
+	}
+
+	redirect, err := code.GenerateRedirectURI("thestate")
+	assert.NoError(t, err)
+	assert.Equal(t, redirect.String(), "https://example.com/callback?code=thecode&state=thestate")
+
+	redirect, err = code.GenerateRedirectURI("")
+	assert.NoError(t, err)
+	assert.Equal(t, redirect.String(), "https://example.com/callback?code=thecode")
+}
+
+func TestOAuth2AuthorizationCode_Invalidate(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	code := AssertExistsAndLoadBean(t, &OAuth2AuthorizationCode{Code: "authcode"}).(*OAuth2AuthorizationCode)
+	assert.NoError(t, code.Invalidate())
+	AssertNotExistsBean(t, &OAuth2AuthorizationCode{Code: "authcode"})
+}
+
+func TestOAuth2AuthorizationCode_TableName(t *testing.T) {
+	assert.Equal(t, "oauth2_authorization_code", new(OAuth2AuthorizationCode).TableName())
+}

models/user.go

@@ -742,6 +742,7 @@ var (
 		"template",
 		"user",
 		"vendor",
+		"login",
 		"robots.txt",
 		".",
 		"..",

modules/auth/auth.go

@@ -7,6 +7,7 @@ package auth
 import (
 	"reflect"
 	"strings"
+	"time"
 
 	"github.com/Unknwon/com"
 	"github.com/go-macaron/binding"
@@ -44,7 +45,7 @@ func SignedInID(ctx *macaron.Context, sess session.Store) int64 {
 			auHead := ctx.Req.Header.Get("Authorization")
 			if len(auHead) > 0 {
 				auths := strings.Fields(auHead)
-				if len(auths) == 2 && auths[0] == "token" {
+				if len(auths) == 2 && (auths[0] == "token" || strings.ToLower(auths[0]) == "bearer") {
 					tokenSHA = auths[1]
 				}
 			}
@@ -52,6 +53,13 @@ func SignedInID(ctx *macaron.Context, sess session.Store) int64 {
 
 		// Let's see if token is valid.
 		if len(tokenSHA) > 0 {
+			if strings.Contains(tokenSHA, ".") {
+				uid := checkOAuthAccessToken(tokenSHA)
+				if uid != 0 {
+					ctx.Data["IsApiToken"] = true
+				}
+				return uid
+			}
 			t, err := models.GetAccessTokenBySHA(tokenSHA)
 			if err != nil {
 				if models.IsErrAccessTokenNotExist(err) || models.IsErrAccessTokenEmpty(err) {
@@ -77,6 +85,29 @@ func SignedInID(ctx *macaron.Context, sess session.Store) int64 {
 	return 0
 }
 
+func checkOAuthAccessToken(accessToken string) int64 {
+	// JWT tokens require a "."
+	if !strings.Contains(accessToken, ".") {
+		return 0
+	}
+	token, err := models.ParseOAuth2Token(accessToken)
+	if err != nil {
+		log.Trace("ParseOAuth2Token", err)
+		return 0
+	}
+	var grant *models.OAuth2Grant
+	if grant, err = models.GetOAuth2GrantByID(token.GrantID); err != nil || grant == nil {
+		return 0
+	}
+	if token.Type != models.TypeAccessToken {
+		return 0
+	}
+	if token.ExpiresAt < time.Now().Unix() || token.IssuedAt > time.Now().Unix() {
+		return 0
+	}
+	return grant.UserID
+}
+
 // SignedInUser returns the user object of signed user.
 // It returns a bool value to indicate whether user uses basic auth or not.
 func SignedInUser(ctx *macaron.Context, sess session.Store) (*models.User, bool) {

modules/auth/user_form.go

@@ -137,6 +137,54 @@ func (f *SignInForm) Validate(ctx *macaron.Context, errs binding.Errors) binding
 	return validate(errs, ctx.Data, f, ctx.Locale)
 }
 
+// AuthorizationForm form for authorizing oauth2 clients
+type AuthorizationForm struct {
+	ResponseType string `binding:"Required;In(code)"`
+	ClientID     string `binding:"Required"`
+	RedirectURI  string
+	State        string
+
+	// PKCE support
+	CodeChallengeMethod string // S256, plain
+	CodeChallenge       string
+}
+
+// Validate valideates the fields
+func (f *AuthorizationForm) Validate(ctx *macaron.Context, errs binding.Errors) binding.Errors {
+	return validate(errs, ctx.Data, f, ctx.Locale)
+}
+
+// GrantApplicationForm form for authorizing oauth2 clients
+type GrantApplicationForm struct {
+	ClientID    string `binding:"Required"`
+	RedirectURI string
+	State       string
+}
+
+// Validate valideates the fields
+func (f *GrantApplicationForm) Validate(ctx *macaron.Context, errs binding.Errors) binding.Errors {
+	return validate(errs, ctx.Data, f, ctx.Locale)
+}
+
+// AccessTokenForm for issuing access tokens from authorization codes or refresh tokens
+type AccessTokenForm struct {
+	GrantType    string
+	ClientID     string
+	ClientSecret string
+	RedirectURI  string
+	// TODO Specify authentication code length to prevent against birthday attacks
+	Code         string
+	RefreshToken string
+
+	// PKCE support
+	CodeVerifier string
+}
+
+// Validate valideates the fields
+func (f *AccessTokenForm) Validate(ctx *macaron.Context, errs binding.Errors) binding.Errors {
+	return validate(errs, ctx.Data, f, ctx.Locale)
+}
+
 //   __________________________________________.___ _______    ________  _________
 //  /   _____/\_   _____/\__    ___/\__    ___/|   |\      \  /  _____/ /   _____/
 //  \_____  \  |    __)_   |    |     |    |   |   |/   |   \/   \  ___ \_____  \
@@ -258,6 +306,17 @@ func (f *NewAccessTokenForm) Validate(ctx *macaron.Context, errs binding.Errors)
 	return validate(errs, ctx.Data, f, ctx.Locale)
 }
 
+// EditOAuth2ApplicationForm form for editing oauth2 applications
+type EditOAuth2ApplicationForm struct {
+	Name        string `binding:"Required;MaxSize(255)" form:"application_name"`
+	RedirectURI string `binding:"Required" form:"redirect_uri"`
+}
+
+// Validate valideates the fields
+func (f *EditOAuth2ApplicationForm) Validate(ctx *macaron.Context, errs binding.Errors) binding.Errors {
+	return validate(errs, ctx.Data, f, ctx.Locale)
+}
+
 // TwoFactorAuthForm for logging in with 2FA token.
 type TwoFactorAuthForm struct {
 	Passcode string `binding:"Required"`

modules/generate/generate.go

@@ -57,16 +57,14 @@ func NewInternalToken() (string, error) {
 	return internalToken, nil
 }
 
-// NewLfsJwtSecret generate a new value intended to be used by LFS_JWT_SECRET.
-func NewLfsJwtSecret() (string, error) {
+// NewJwtSecret generate a new value intended to be used by LFS_JWT_SECRET.
+func NewJwtSecret() (string, error) {
 	JWTSecretBytes := make([]byte, 32)
 	_, err := io.ReadFull(rand.Reader, JWTSecretBytes)
 	if err != nil {
 		return "", err
 	}
-
-	JWTSecretBase64 := base64.RawURLEncoding.EncodeToString(JWTSecretBytes)
-	return JWTSecretBase64, nil
+	return base64.RawURLEncoding.EncodeToString(JWTSecretBytes), nil
 }
 
 // NewSecretKey generate a new value intended to be used by SECRET_KEY.

modules/secret/secret.go

@@ -0,0 +1,33 @@
+// Copyright 2019 The Gitea 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 secret
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+)
+
+// New creats a new secret
+func New() (string, error) {
+	return NewWithLength(32)
+}
+
+// NewWithLength creates a new secret for a given length
+func NewWithLength(length int64) (string, error) {
+	return randomString(length)
+}
+
+func randomBytes(len int64) ([]byte, error) {
+	b := make([]byte, len)
+	if _, err := rand.Read(b); err != nil {
+		return nil, err
+	}
+	return b, nil
+}
+
+func randomString(len int64) (string, error) {
+	b, err := randomBytes(len)
+	return base64.URLEncoding.EncodeToString(b), err
+}

modules/secret/secret_test.go

@@ -0,0 +1,22 @@
+// Copyright 2019 The Gitea 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 secret
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNew(t *testing.T) {
+	result, err := New()
+	assert.NoError(t, err)
+	assert.True(t, len(result) > 32)
+
+	result2, err := New()
+	assert.NoError(t, err)
+	// check if secrets
+	assert.NotEqual(t, result, result2)
+}

modules/setting/setting.go

@@ -560,6 +560,18 @@ var (
 		DefaultGitTreesPerPage: 1000,
 	}
 
+	OAuth2 = struct {
+		Enable                     bool
+		AccessTokenExpirationTime  int64
+		RefreshTokenExpirationTime int64
+		JWTSecretBytes             []byte `ini:"-"`
+		JWTSecretBase64            string `ini:"JWT_SECRET"`
+	}{
+		Enable:                     true,
+		AccessTokenExpirationTime:  3600,
+		RefreshTokenExpirationTime: 730,
+	}
+
 	U2F = struct {
 		AppID         string
 		TrustedFacets []string
@@ -922,7 +934,7 @@ func NewContext() {
 		n, err := base64.RawURLEncoding.Decode(LFS.JWTSecretBytes, []byte(LFS.JWTSecretBase64))
 
 		if err != nil || n != 32 {
-			LFS.JWTSecretBase64, err = generate.NewLfsJwtSecret()
+			LFS.JWTSecretBase64, err = generate.NewJwtSecret()
 			if err != nil {
 				log.Fatal(4, "Error generating JWT Secret for custom config: %v", err)
 				return
@@ -949,6 +961,41 @@ func NewContext() {
 		}
 	}
 
+	if err = Cfg.Section("oauth2").MapTo(&OAuth2); err != nil {
+		log.Fatal(4, "Failed to OAuth2 settings: %v", err)
+		return
+	}
+
+	if OAuth2.Enable {
+		OAuth2.JWTSecretBytes = make([]byte, 32)
+		n, err := base64.RawURLEncoding.Decode(OAuth2.JWTSecretBytes, []byte(OAuth2.JWTSecretBase64))
+
+		if err != nil || n != 32 {
+			OAuth2.JWTSecretBase64, err = generate.NewJwtSecret()
+			if err != nil {
+				log.Fatal(4, "error generating JWT secret: %v", err)
+				return
+			}
+			cfg := ini.Empty()
+			if com.IsFile(CustomConf) {
+				if err := cfg.Append(CustomConf); err != nil {
+					log.Error(4, "failed to load custom conf %s: %v", CustomConf, err)
+					return
+				}
+			}
+			cfg.Section("oauth2").Key("JWT_SECRET").SetValue(OAuth2.JWTSecretBase64)
+
+			if err := os.MkdirAll(filepath.Dir(CustomConf), os.ModePerm); err != nil {
+				log.Fatal(4, "failed to create '%s': %v", CustomConf, err)
+				return
+			}
+			if err := cfg.SaveTo(CustomConf); err != nil {
+				log.Fatal(4, "error saving generating JWT secret to custom config: %v", err)
+				return
+			}
+		}
+	}
+
 	sec = Cfg.Section("security")
 	InstallLock = sec.Key("INSTALL_LOCK").MustBool(false)
 	SecretKey = sec.Key("SECRET_KEY").MustString("!#@FDEWREWR&*(")

options/locale/locale_en-US.ini

@@ -243,6 +243,13 @@ openid_register_desc = The chosen OpenID URI is unknown. Associate it with a new
 openid_signin_desc = Enter your OpenID URI. For example: https://anne.me, bob.openid.org.cn or gnusocial.net/carry.
 disable_forgot_password_mail = Password reset is disabled. Please contact your site administrator.
 email_domain_blacklisted = You cannot register with your email address.
+authorize_application = Authorize Application
+authroize_redirect_notice = You will be redirected to %s if you authorize this application.
+authorize_application_created_by = This application was created by %s.
+authorize_application_description = If you grant the access, it will be able to access and write to all your account information, including private repos and organisations.
+authorize_title = Authorize "%s" to access your account?
+authorization_failed = Authorization failed
+authorization_failed_desc = The authorization failed because we detected an invalid request. Please contact the maintainer of the app you've tried to authorize.
 
 [mail]
 activate_account = Please activate your account
@@ -466,6 +473,31 @@ access_token_deletion = Delete Access Token
 access_token_deletion_desc = Deleting a token will revoke access to your account for applications using it. Continue?
 delete_token_success = The token has been deleted. Applications using it no longer have access to your account.
 
+manage_oauth2_applications = Manage OAuth2 Applications
+edit_oauth2_application = Edit OAuth2 Application
+oauth2_applications_desc = OAuth2 applications enables your third-party application to securely authenticate users at this Gitea instance.
+remove_oauth2_application = Remove OAuth2 Application
+remove_oauth2_application_desc = Removing an OAuth2 application will revoke access to all signed access tokes. Continue?
+remove_oauth2_application_success = The application has been deleted.
+create_oauth2_application = Create a new OAuth2 Application
+create_oauth2_application_button = Create Application
+create_oauth2_application_success = You've successfully created a new OAuth2 application.
+update_oauth2_application_success = You've successfully updated the OAuth2 application.
+oauth2_application_name = Application Name
+oauth2_select_type = Which application type fits?
+oauth2_type_web = Web (e.g. Node.JS, Tomcat, Go)
+oauth2_type_native = Native (e.g. Mobile, Desktop, Browser)
+oauth2_redirect_uri = Redirect URI
+save_application = Save
+oauth2_client_id = Client ID
+oauth2_client_secret = Client Secret
+oauth2_regenerate_secret = Regenerate Secret
+oauth2_regenerate_secret_hint = Lost your secret?
+oauth2_client_secret_hint = The secret won't be visible if you revisit this page. Please save your secret.
+oauth2_application_edit = Edit
+oauth2_application_create_description = OAuth2 applications gives your third-party application access to user accounts on this instance.
+oauth2_application_remove_description = Removing an OAuth2 application will prevent it to access authorized user accounts on this instance. Continue?
+
 twofa_desc = Two-factor authentication enhances the security of your account.
 twofa_is_enrolled = Your account is currently <strong>enrolled</strong> in two-factor authentication.
 twofa_not_enrolled = Your account is not currently enrolled in two-factor authentication.

public/less/_base.less

@@ -633,3 +633,7 @@ footer {
 .archived-icon{
     color: lighten(#000, 70%) !important;
 }
+
+.oauth2-authorize-application-box {
+    margin-top: 3em !important;
+}

routers/install.go

@@ -266,7 +266,7 @@ func InstallPost(ctx *context.Context, form auth.InstallForm) {
 		cfg.Section("server").Key("LFS_START_SERVER").SetValue("true")
 		cfg.Section("server").Key("LFS_CONTENT_PATH").SetValue(form.LFSRootPath)
 		var secretKey string
-		if secretKey, err = generate.NewLfsJwtSecret(); err != nil {
+		if secretKey, err = generate.NewJwtSecret(); err != nil {
 			ctx.RenderWithErr(ctx.Tr("install.lfs_jwt_secret_failed", err), tplInstall, &form)
 			return
 		}

routers/routes/routes.go

@@ -257,6 +257,14 @@ func RegisterRoutes(m *macaron.Macaron) {
 		})
 	}, reqSignOut)
 
+	m.Group("/login/oauth", func() {
+		m.Get("/authorize", bindIgnErr(auth.AuthorizationForm{}), user.AuthorizeOAuth)
+		m.Post("/grant", bindIgnErr(auth.GrantApplicationForm{}), user.GrantApplicationOAuth)
+		// TODO manage redirection
+		m.Post("/authorize", bindIgnErr(auth.AuthorizationForm{}), user.AuthorizeOAuth)
+	}, ignSignInAndCsrf, reqSignIn)
+	m.Post("/login/oauth/access_token", bindIgnErr(auth.AccessTokenForm{}), ignSignInAndCsrf, user.AccessTokenOAuth)
+
 	m.Group("/user/settings", func() {
 		m.Get("", userSetting.Profile)
 		m.Post("", bindIgnErr(auth.UpdateProfileForm{}), userSetting.ProfilePost)
@@ -291,6 +299,12 @@ func RegisterRoutes(m *macaron.Macaron) {
 			}, openIDSignInEnabled)
 			m.Post("/account_link", userSetting.DeleteAccountLink)
 		})
+		m.Group("/applications/oauth2", func() {
+			m.Get("/:id", userSetting.OAuth2ApplicationShow)
+			m.Post("/:id", bindIgnErr(auth.EditOAuth2ApplicationForm{}), userSetting.OAuthApplicationsEdit)
+			m.Post("", bindIgnErr(auth.EditOAuth2ApplicationForm{}), userSetting.OAuthApplicationsPost)
+			m.Post("/delete", userSetting.DeleteOAuth2Application)
+		})
 		m.Combo("/applications").Get(userSetting.Applications).
 			Post(bindIgnErr(auth.NewAccessTokenForm{}), userSetting.ApplicationsPost)
 		m.Post("/applications/delete", userSetting.DeleteApplication)

routers/user/oauth.go

@@ -0,0 +1,452 @@
+// Copyright 2019 The Gitea 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 user
+
+import (
+	"fmt"
+	"net/url"
+
+	"github.com/dgrijalva/jwt-go"
+	"github.com/go-macaron/binding"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/auth"
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+)
+
+const (
+	tplGrantAccess base.TplName = "user/auth/grant"
+	tplGrantError  base.TplName = "user/auth/grant_error"
+)
+
+// TODO move error and responses to SDK or models
+
+// AuthorizeErrorCode represents an error code specified in RFC 6749
+type AuthorizeErrorCode string
+
+const (
+	// ErrorCodeInvalidRequest represents the according error in RFC 6749
+	ErrorCodeInvalidRequest AuthorizeErrorCode = "invalid_request"
+	// ErrorCodeUnauthorizedClient represents the according error in RFC 6749
+	ErrorCodeUnauthorizedClient AuthorizeErrorCode = "unauthorized_client"
+	// ErrorCodeAccessDenied represents the according error in RFC 6749
+	ErrorCodeAccessDenied AuthorizeErrorCode = "access_denied"
+	// ErrorCodeUnsupportedResponseType represents the according error in RFC 6749
+	ErrorCodeUnsupportedResponseType AuthorizeErrorCode = "unsupported_response_type"
+	// ErrorCodeInvalidScope represents the according error in RFC 6749
+	ErrorCodeInvalidScope AuthorizeErrorCode = "invalid_scope"
+	// ErrorCodeServerError represents the according error in RFC 6749
+	ErrorCodeServerError AuthorizeErrorCode = "server_error"
+	// ErrorCodeTemporaryUnavailable represents the according error in RFC 6749
+	ErrorCodeTemporaryUnavailable AuthorizeErrorCode = "temporarily_unavailable"
+)
+
+// AuthorizeError represents an error type specified in RFC 6749
+type AuthorizeError struct {
+	ErrorCode        AuthorizeErrorCode `json:"error" form:"error"`
+	ErrorDescription string
+	State            string
+}
+
+// Error returns the error message
+func (err AuthorizeError) Error() string {
+	return fmt.Sprintf("%s: %s", err.ErrorCode, err.ErrorDescription)
+}
+
+// AccessTokenErrorCode represents an error code specified in RFC 6749
+type AccessTokenErrorCode string
+
+const (
+	// AccessTokenErrorCodeInvalidRequest represents an error code specified in RFC 6749
+	AccessTokenErrorCodeInvalidRequest AccessTokenErrorCode = "invalid_request"
+	// AccessTokenErrorCodeInvalidClient represents an error code specified in RFC 6749
+	AccessTokenErrorCodeInvalidClient = "invalid_client"
+	// AccessTokenErrorCodeInvalidGrant represents an error code specified in RFC 6749
+	AccessTokenErrorCodeInvalidGrant = "invalid_grant"
+	// AccessTokenErrorCodeUnauthorizedClient represents an error code specified in RFC 6749
+	AccessTokenErrorCodeUnauthorizedClient = "unauthorized_client"
+	// AccessTokenErrorCodeUnsupportedGrantType represents an error code specified in RFC 6749
+	AccessTokenErrorCodeUnsupportedGrantType = "unsupported_grant_type"
+	// AccessTokenErrorCodeInvalidScope represents an error code specified in RFC 6749
+	AccessTokenErrorCodeInvalidScope = "invalid_scope"
+)
+
+// AccessTokenError represents an error response specified in RFC 6749
+type AccessTokenError struct {
+	ErrorCode        AccessTokenErrorCode `json:"error" form:"error"`
+	ErrorDescription string               `json:"error_description"`
+}
+
+// Error returns the error message
+func (err AccessTokenError) Error() string {
+	return fmt.Sprintf("%s: %s", err.ErrorCode, err.ErrorDescription)
+}
+
+// TokenType specifies the kind of token
+type TokenType string
+
+const (
+	// TokenTypeBearer represents a token type specified in RFC 6749
+	TokenTypeBearer TokenType = "bearer"
+	// TokenTypeMAC represents a token type specified in RFC 6749
+	TokenTypeMAC = "mac"
+)
+
+// AccessTokenResponse represents a successful access token response
+type AccessTokenResponse struct {
+	AccessToken string    `json:"access_token"`
+	TokenType   TokenType `json:"token_type"`
+	ExpiresIn   int64     `json:"expires_in"`
+	// TODO implement RefreshToken
+	RefreshToken string `json:"refresh_token"`
+}
+
+func newAccessTokenResponse(grant *models.OAuth2Grant) (*AccessTokenResponse, *AccessTokenError) {
+	if err := grant.IncreaseCounter(); err != nil {
+		return nil, &AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeInvalidGrant,
+			ErrorDescription: "cannot increase the grant counter",
+		}
+	}
+	// generate access token to access the API
+	expirationDate := util.TimeStampNow().Add(setting.OAuth2.AccessTokenExpirationTime)
+	accessToken := &models.OAuth2Token{
+		GrantID: grant.ID,
+		Type:    models.TypeAccessToken,
+		StandardClaims: jwt.StandardClaims{
+			ExpiresAt: expirationDate.AsTime().Unix(),
+		},
+	}
+	signedAccessToken, err := accessToken.SignToken()
+	if err != nil {
+		return nil, &AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeInvalidRequest,
+			ErrorDescription: "cannot sign token",
+		}
+	}
+
+	// generate refresh token to request an access token after it expired later
+	refreshExpirationDate := util.TimeStampNow().Add(setting.OAuth2.RefreshTokenExpirationTime * 60 * 60).AsTime().Unix()
+	refreshToken := &models.OAuth2Token{
+		GrantID: grant.ID,
+		Counter: grant.Counter,
+		Type:    models.TypeRefreshToken,
+		StandardClaims: jwt.StandardClaims{
+			ExpiresAt: refreshExpirationDate,
+		},
+	}
+	signedRefreshToken, err := refreshToken.SignToken()
+	if err != nil {
+		return nil, &AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeInvalidRequest,
+			ErrorDescription: "cannot sign token",
+		}
+	}
+
+	return &AccessTokenResponse{
+		AccessToken:  signedAccessToken,
+		TokenType:    TokenTypeBearer,
+		ExpiresIn:    setting.OAuth2.AccessTokenExpirationTime,
+		RefreshToken: signedRefreshToken,
+	}, nil
+}
+
+// AuthorizeOAuth manages authorize requests
+func AuthorizeOAuth(ctx *context.Context, form auth.AuthorizationForm) {
+	errs := binding.Errors{}
+	errs = form.Validate(ctx.Context, errs)
+
+	app, err := models.GetOAuth2ApplicationByClientID(form.ClientID)
+	if err != nil {
+		if models.IsErrOauthClientIDInvalid(err) {
+			handleAuthorizeError(ctx, AuthorizeError{
+				ErrorCode:        ErrorCodeUnauthorizedClient,
+				ErrorDescription: "Client ID not registered",
+				State:            form.State,
+			}, "")
+			return
+		}
+		ctx.ServerError("GetOAuth2ApplicationByClientID", err)
+		return
+	}
+	if err := app.LoadUser(); err != nil {
+		ctx.ServerError("LoadUser", err)
+		return
+	}
+
+	if !app.ContainsRedirectURI(form.RedirectURI) {
+		handleAuthorizeError(ctx, AuthorizeError{
+			ErrorCode:        ErrorCodeInvalidRequest,
+			ErrorDescription: "Unregistered Redirect URI",
+			State:            form.State,
+		}, "")
+		return
+	}
+
+	if form.ResponseType != "code" {
+		handleAuthorizeError(ctx, AuthorizeError{
+			ErrorCode:        ErrorCodeUnsupportedResponseType,
+			ErrorDescription: "Only code response type is supported.",
+			State:            form.State,
+		}, form.RedirectURI)
+		return
+	}
+
+	// pkce support
+	switch form.CodeChallengeMethod {
+	case "S256":
+	case "plain":
+		if err := ctx.Session.Set("CodeChallengeMethod", form.CodeChallengeMethod); err != nil {
+			handleAuthorizeError(ctx, AuthorizeError{
+				ErrorCode:        ErrorCodeServerError,
+				ErrorDescription: "cannot set code challenge method",
+				State:            form.State,
+			}, form.RedirectURI)
+			return
+		}
+		if err := ctx.Session.Set("CodeChallengeMethod", form.CodeChallenge); err != nil {
+			handleAuthorizeError(ctx, AuthorizeError{
+				ErrorCode:        ErrorCodeServerError,
+				ErrorDescription: "cannot set code challenge",
+				State:            form.State,
+			}, form.RedirectURI)
+			return
+		}
+		break
+	case "":
+		break
+	default:
+		handleAuthorizeError(ctx, AuthorizeError{
+			ErrorCode:        ErrorCodeInvalidRequest,
+			ErrorDescription: "unsupported code challenge method",
+			State:            form.State,
+		}, form.RedirectURI)
+		return
+	}
+
+	grant, err := app.GetGrantByUserID(ctx.User.ID)
+	if err != nil {
+		handleServerError(ctx, form.State, form.RedirectURI)
+		return
+	}
+
+	// Redirect if user already granted access
+	if grant != nil {
+		code, err := grant.GenerateNewAuthorizationCode(form.RedirectURI, form.CodeChallenge, form.CodeChallengeMethod)
+		if err != nil {
+			handleServerError(ctx, form.State, form.RedirectURI)
+			return
+		}
+		redirect, err := code.GenerateRedirectURI(form.State)
+		if err != nil {
+			handleServerError(ctx, form.State, form.RedirectURI)
+			return
+		}
+		ctx.Redirect(redirect.String(), 302)
+		return
+	}
+
+	// show authorize page to grant access
+	ctx.Data["Application"] = app
+	ctx.Data["RedirectURI"] = form.RedirectURI
+	ctx.Data["State"] = form.State
+	ctx.Data["ApplicationUserLink"] = "<a href=\"" + setting.LocalURL + app.User.LowerName + "\">@" + app.User.Name + "</a>"
+	ctx.Data["ApplicationRedirectDomainHTML"] = "<strong>" + form.RedirectURI + "</strong>"
+	// TODO document SESSION <=> FORM
+	ctx.Session.Set("client_id", app.ClientID)
+	ctx.Session.Set("redirect_uri", form.RedirectURI)
+	ctx.Session.Set("state", form.State)
+	ctx.HTML(200, tplGrantAccess)
+}
+
+// GrantApplicationOAuth manages the post request submitted when a user grants access to an application
+func GrantApplicationOAuth(ctx *context.Context, form auth.GrantApplicationForm) {
+	if ctx.Session.Get("client_id") != form.ClientID || ctx.Session.Get("state") != form.State ||
+		ctx.Session.Get("redirect_uri") != form.RedirectURI {
+		ctx.Error(400)
+		return
+	}
+	app, err := models.GetOAuth2ApplicationByClientID(form.ClientID)
+	if err != nil {
+		ctx.ServerError("GetOAuth2ApplicationByClientID", err)
+		return
+	}
+	grant, err := app.CreateGrant(ctx.User.ID)
+	if err != nil {
+		handleAuthorizeError(ctx, AuthorizeError{
+			State:            form.State,
+			ErrorDescription: "cannot create grant for user",
+			ErrorCode:        ErrorCodeServerError,
+		}, form.RedirectURI)
+		return
+	}
+
+	var codeChallenge, codeChallengeMethod string
+	codeChallenge, _ = ctx.Session.Get("CodeChallenge").(string)
+	codeChallengeMethod, _ = ctx.Session.Get("CodeChallengeMethod").(string)
+
+	code, err := grant.GenerateNewAuthorizationCode(form.RedirectURI, codeChallenge, codeChallengeMethod)
+	if err != nil {
+		handleServerError(ctx, form.State, form.RedirectURI)
+		return
+	}
+	redirect, err := code.GenerateRedirectURI(form.State)
+	if err != nil {
+		handleServerError(ctx, form.State, form.RedirectURI)
+	}
+	ctx.Redirect(redirect.String(), 302)
+}
+
+// AccessTokenOAuth manages all access token requests by the client
+func AccessTokenOAuth(ctx *context.Context, form auth.AccessTokenForm) {
+	switch form.GrantType {
+	case "refresh_token":
+		handleRefreshToken(ctx, form)
+		return
+	case "authorization_code":
+		handleAuthorizationCode(ctx, form)
+		return
+	default:
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeUnsupportedGrantType,
+			ErrorDescription: "Only refresh_token or authorization_code grant type is supported",
+		})
+	}
+}
+
+func handleRefreshToken(ctx *context.Context, form auth.AccessTokenForm) {
+	token, err := models.ParseOAuth2Token(form.RefreshToken)
+	if err != nil {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeUnauthorizedClient,
+			ErrorDescription: "client is not authorized",
+		})
+		return
+	}
+	// get grant before increasing counter
+	grant, err := models.GetOAuth2GrantByID(token.GrantID)
+	if err != nil || grant == nil {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeInvalidGrant,
+			ErrorDescription: "grant does not exist",
+		})
+		return
+	}
+
+	// check if token got already used
+	if grant.Counter != token.Counter || token.Counter == 0 {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeUnauthorizedClient,
+			ErrorDescription: "token was already used",
+		})
+		log.Warn("A client tried to use a refresh token for grant_id = %d was used twice!", grant.ID)
+		return
+	}
+	accessToken, tokenErr := newAccessTokenResponse(grant)
+	if tokenErr != nil {
+		handleAccessTokenError(ctx, *tokenErr)
+		return
+	}
+	ctx.JSON(200, accessToken)
+}
+
+func handleAuthorizationCode(ctx *context.Context, form auth.AccessTokenForm) {
+	app, err := models.GetOAuth2ApplicationByClientID(form.ClientID)
+	if err != nil {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeInvalidClient,
+			ErrorDescription: "cannot load client",
+		})
+		return
+	}
+	if !app.ValidateClientSecret([]byte(form.ClientSecret)) {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeUnauthorizedClient,
+			ErrorDescription: "client is not authorized",
+		})
+		return
+	}
+	if form.RedirectURI != "" && !app.ContainsRedirectURI(form.RedirectURI) {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeUnauthorizedClient,
+			ErrorDescription: "client is not authorized",
+		})
+		return
+	}
+	authorizationCode, err := models.GetOAuth2AuthorizationByCode(form.Code)
+	if err != nil || authorizationCode == nil {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeUnauthorizedClient,
+			ErrorDescription: "client is not authorized",
+		})
+		return
+	}
+	// check if code verifier authorizes the client, PKCE support
+	if !authorizationCode.ValidateCodeChallenge(form.CodeVerifier) {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeUnauthorizedClient,
+			ErrorDescription: "client is not authorized",
+		})
+		return
+	}
+	// check if granted for this application
+	if authorizationCode.Grant.ApplicationID != app.ID {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeInvalidGrant,
+			ErrorDescription: "invalid grant",
+		})
+		return
+	}
+	// remove token from database to deny duplicate usage
+	if err := authorizationCode.Invalidate(); err != nil {
+		handleAccessTokenError(ctx, AccessTokenError{
+			ErrorCode:        AccessTokenErrorCodeInvalidRequest,
+			ErrorDescription: "cannot proceed your request",
+		})
+	}
+	resp, tokenErr := newAccessTokenResponse(authorizationCode.Grant)
+	if tokenErr != nil {
+		handleAccessTokenError(ctx, *tokenErr)
+		return
+	}
+	// send successful response
+	ctx.JSON(200, resp)
+}
+
+func handleAccessTokenError(ctx *context.Context, acErr AccessTokenError) {
+	ctx.JSON(400, acErr)
+}
+
+func handleServerError(ctx *context.Context, state string, redirectURI string) {
+	handleAuthorizeError(ctx, AuthorizeError{
+		ErrorCode:        ErrorCodeServerError,
+		ErrorDescription: "A server error occurred",
+		State:            state,
+	}, redirectURI)
+}
+
+func handleAuthorizeError(ctx *context.Context, authErr AuthorizeError, redirectURI string) {
+	if redirectURI == "" {
+		log.Warn("Authorization failed: %v", authErr.ErrorDescription)
+		ctx.Data["Error"] = authErr
+		ctx.HTML(400, tplGrantError)
+		return
+	}
+	redirect, err := url.Parse(redirectURI)
+	if err != nil {
+		ctx.ServerError("url.Parse", err)
+		return
+	}
+	q := redirect.Query()
+	q.Set("error", string(authErr.ErrorCode))
+	q.Set("error_description", authErr.ErrorDescription)
+	q.Set("state", authErr.State)
+	redirect.RawQuery = q.Encode()
+	ctx.Redirect(redirect.String(), 302)
+}

routers/user/setting/applications.go

@@ -74,4 +74,12 @@ func loadApplicationsData(ctx *context.Context) {
 		return
 	}
 	ctx.Data["Tokens"] = tokens
+	ctx.Data["EnableOAuth2"] = setting.OAuth2.Enable
+	if setting.OAuth2.Enable {
+		ctx.Data["Applications"], err = models.GetOAuth2ApplicationsByUserID(ctx.User.ID)
+		if err != nil {
+			ctx.ServerError("GetOAuth2ApplicationsByUserID", err)
+			return
+		}
+	}
 }

routers/user/setting/oauth2.go

@@ -0,0 +1,112 @@
+// Copyright 2019 The Gitea 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 setting
+
+import (
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/auth"
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+const (
+	tplSettingsOAuthApplications base.TplName = "user/settings/applications_oauth2_edit"
+)
+
+// OAuthApplicationsPost response for adding a oauth2 application
+func OAuthApplicationsPost(ctx *context.Context, form auth.EditOAuth2ApplicationForm) {
+	ctx.Data["Title"] = ctx.Tr("settings")
+	ctx.Data["PageIsSettingsApplications"] = true
+
+	if ctx.HasError() {
+		loadApplicationsData(ctx)
+
+		ctx.HTML(200, tplSettingsApplications)
+		return
+	}
+	// TODO validate redirect URI
+	app, err := models.CreateOAuth2Application(models.CreateOAuth2ApplicationOptions{
+		Name:         form.Name,
+		RedirectURIs: []string{form.RedirectURI},
+		UserID:       ctx.User.ID,
+	})
+	if err != nil {
+		ctx.ServerError("CreateOAuth2Application", err)
+		return
+	}
+	ctx.Flash.Success(ctx.Tr("settings.create_oauth2_application_success"))
+	ctx.Data["App"] = app
+	ctx.Data["ClientSecret"], err = app.GenerateClientSecret()
+	if err != nil {
+		ctx.ServerError("GenerateClientSecret", err)
+		return
+	}
+	ctx.HTML(200, tplSettingsOAuthApplications)
+}
+
+// OAuthApplicationsEdit response for editing oauth2 application
+func OAuthApplicationsEdit(ctx *context.Context, form auth.EditOAuth2ApplicationForm) {
+	ctx.Data["Title"] = ctx.Tr("settings")
+	ctx.Data["PageIsSettingsApplications"] = true
+
+	if ctx.HasError() {
+		loadApplicationsData(ctx)
+
+		ctx.HTML(200, tplSettingsApplications)
+		return
+	}
+	// TODO validate redirect URI
+	if err := models.UpdateOAuth2Application(models.UpdateOAuth2ApplicationOptions{
+		ID:           ctx.ParamsInt64("id"),
+		Name:         form.Name,
+		RedirectURIs: []string{form.RedirectURI},
+		UserID:       ctx.User.ID,
+	}); err != nil {
+		ctx.ServerError("UpdateOAuth2Application", err)
+		return
+	}
+	var err error
+	if ctx.Data["App"], err = models.GetOAuth2ApplicationByID(ctx.ParamsInt64("id")); err != nil {
+		ctx.ServerError("GetOAuth2ApplicationByID", err)
+		return
+	}
+	ctx.Flash.Success(ctx.Tr("settings.update_oauth2_application_success"))
+	ctx.HTML(200, tplSettingsOAuthApplications)
+}
+
+// OAuth2ApplicationShow displays the given application
+func OAuth2ApplicationShow(ctx *context.Context) {
+	app, err := models.GetOAuth2ApplicationByID(ctx.ParamsInt64("id"))
+	if err != nil {
+		if models.IsErrOAuthApplicationNotFound(err) {
+			ctx.NotFound("Application not found", err)
+			return
+		}
+		ctx.ServerError("GetOAuth2ApplicationByID", err)
+		return
+	}
+	if app.UID != ctx.User.ID {
+		ctx.NotFound("Application not found", nil)
+		return
+	}
+	ctx.Data["App"] = app
+	ctx.HTML(200, tplSettingsOAuthApplications)
+}
+
+// DeleteOAuth2Application deletes the given oauth2 application
+func DeleteOAuth2Application(ctx *context.Context) {
+	if err := models.DeleteOAuth2Application(ctx.QueryInt64("id"), ctx.User.ID); err != nil {
+		ctx.ServerError("DeleteOAuth2Application", err)
+		return
+	}
+	log.Trace("OAuth2 Application deleted: %s", ctx.User.Name)
+
+	ctx.Flash.Success(ctx.Tr("settings.remove_oauth2_application_success"))
+	ctx.JSON(200, map[string]interface{}{
+		"redirect": setting.AppSubURL + "/user/settings/applications",
+	})
+}

templates/user/auth/grant.tmpl

@@ -0,0 +1,31 @@
+{{template "base/head" .}}
+<div class="ui one column stackable center aligned page grid oauth2-authorize-application-box">
+	<div class="column seven wide">
+		<div class="ui middle centered raised segments">
+			<h3 class="ui top attached header">
+				{{.i18n.Tr "auth.authorize_title" .Application.Name}}
+			</h3>
+			<div class="ui attached segment">
+				{{template "base/alert" .}}
+				<p>
+					<b>{{.i18n.Tr "auth.authorize_application_description"}}</b><br/>
+					{{.i18n.Tr "auth.authorize_application_created_by" .ApplicationUserLink | Str2html}}
+				</p>
+			</div>
+			<div class="ui attached segment">
+				<p>{{.i18n.Tr "auth.authroize_redirect_notice" .ApplicationRedirectDomainHTML | Str2html}}</p>
+			</div>
+			<div class="ui attached segment">
+				<form method="post" action="{{.AppSubUrl}}/login/oauth/grant">
+					{{.CsrfTokenHtml}}
+					<input type="hidden" name="client_id" value="{{.Application.ClientID}}">
+					<input type="hidden" name="state" value="{{.State}}">
+					<input type="hidden" name="redirect_uri" value="{{.RedirectURI}}">
+					<input type="submit" id="authorize-app" value="{{.i18n.Tr "auth.authorize_application"}}" class="ui red inline button"/>
+					<a href="{{.RedirectURI}}" class="ui basic primary inline button">Cancel</a>
+				</form>
+			</div>
+		</div>
+	</div>
+</div>
+{{template "base/footer" .}}

templates/user/auth/grant_error.tmpl

@@ -0,0 +1,16 @@
+{{template "base/head" .}}
+{{if .IsRepo}}<div class="repository">{{template "repo/header" .}}</div>{{end}}
+<div class="ui one column stackable center aligned page grid oauth2-authorize-application-box">
+	<div class="column seven wide">
+		<div class="ui middle centered raised segments">
+			<h1 class="ui top attached header">
+				{{.i18n.Tr "auth.authorization_failed" }}
+			</h1>
+			<h3 class="ui attached segment">{{.Error.ErrorDescription}}</h3>
+			<div class="ui attached segment">
+				<p>{{.i18n.Tr "auth.authorization_failed_desc"}}</p>
+			</div>
+		</div>
+	</div>
+</div>
+{{template "base/footer" .}}

templates/user/settings/applications.tmpl

@@ -45,6 +45,10 @@
 				</button>
 			</form>
 		</div>
+
+		{{if .EnableOAuth2}}
+			{{template "user/settings/applications_oauth2" .}}
+		{{end}}
 	</div>
 </div>
 

templates/user/settings/applications_oauth2.tmpl

@@ -0,0 +1,58 @@
+<h4 class="ui top attached header">
+	{{.i18n.Tr "settings.manage_oauth2_applications"}}
+</h4>
+<div class="ui attached segment">
+	<div class="ui key list">
+		<div class="item">
+			{{.i18n.Tr "settings.oauth2_application_create_description"}}
+		</div>
+		{{range $app := .Applications}}
+			<div class="item">
+				<div class="right floated content">
+					<a href="{{$.Link}}/oauth2/{{$app.ID}}" class="ui primary tiny icon button">
+						<i class="pencil alternate icon"></i>
+						{{$.i18n.Tr "settings.oauth2_application_edit"}}
+					</a>
+					<button class="ui red tiny button delete-button" id="remove-gitea-oauth2-application"
+							data-url="{{AppSubUrl}}/user/settings/applications/oauth2/delete"
+							data-id="{{$app.ID}}">
+						{{$.i18n.Tr "settings.delete_key"}}
+					</button>
+				</div>
+				<div class="content">
+					<strong>{{$app.Name}}</strong>
+				</div>
+			</div>
+		{{end}}
+	</div>
+</div>
+<div class="ui attached bottom segment">
+	<h5 class="ui top header">
+		{{.i18n.Tr "settings.create_oauth2_application" }}
+	</h5>
+	<form class="ui form ignore-dirty" action="{{.Link}}/oauth2" method="post">
+		{{.CsrfTokenHtml}}
+		<div class="field {{if .Err_AppName}}error{{end}}">
+			<label for="application-name">{{.i18n.Tr "settings.oauth2_application_name"}}</label>
+			<input id="application-name" name="application_name" value="{{.application_name}}" required>
+		</div>
+		<div class="field {{if .Err_RedirectURI}}error{{end}}">
+			<label for="redirect-uri">{{.i18n.Tr "settings.oauth2_redirect_uri"}}</label>
+			<input type="url" name="redirect_uri" id="redirect-uri">
+		</div>
+		<button class="ui green button">
+			{{.i18n.Tr "settings.create_oauth2_application_button"}}
+		</button>
+	</form>
+</div>
+
+<div class="ui small basic delete modal" id="remove-gitea-oauth2-application">
+	<div class="ui icon header">
+		<i class="trash icon"></i>
+		{{.i18n.Tr "settings.remove_oauth2_application"}}
+	</div>
+	<div class="content">
+		<p>{{.i18n.Tr "settings.oauth2_application_remove_description"}}</p>
+	</div>
+	{{template "base/delete_modal_actions" .}}
+</div>

templates/user/settings/applications_oauth2_edit.tmpl

@@ -0,0 +1,66 @@
+{{template "base/head" .}}
+<div class="user settings applications">
+	{{template "user/settings/navbar" .}}
+	<div class="ui container">
+		{{template "base/alert" .}}
+		<h4 class="ui top attached header">
+			{{.i18n.Tr "settings.edit_oauth2_application"}}
+		</h4>
+		<div class="ui attached segment">
+			{{template "base/alert" .}}
+			<p>{{.i18n.Tr "settings.oauth2_application_create_description"}}</p>
+		</div>
+		<div class="ui attached segment form ignore-dirty">
+			{{.CsrfTokenHtml}}
+			<div class="field">
+				<label for="client-id">{{.i18n.Tr "settings.oauth2_client_id"}}</label>
+				<input id="client-id" readonly value="{{.App.ClientID}}">
+			</div>
+			{{if .ClientSecret}}
+				<div class="field">
+					<label for="client-secret">{{.i18n.Tr "settings.oauth2_client_secret"}}</label>
+					<input id="client-secret" type="text" readonly value="{{.ClientSecret}}">
+				</div>
+			{{else}}
+				<div class="field">
+					<label for="client-secret">{{.i18n.Tr "settings.oauth2_client_secret"}}</label>
+					<input id="client-secret" type="password" readonly value="averysecuresecret">
+				</div>
+			{{end}}
+			<div class="item">
+				<!-- TODO add regenerate secret functionality */ -->
+				{{.i18n.Tr "settings.oauth2_regenerate_secret_hint"}}
+				<a onclick="alert('Not yet implemented.')">{{.i18n.Tr "settings.oauth2_regenerate_secret"}}</a>
+			</div>
+		</div>
+		<div class="ui attached bottom segment">
+			<form class="ui form ignore-dirty" action="{{$.AppSubURL}}/user/settings/applications/oauth2/{{.App.ID}}" method="post">
+				{{.CsrfTokenHtml}}
+				<div class="field {{if .Err_AppName}}error{{end}}">
+					<label for="application-name">{{.i18n.Tr "settings.oauth2_application_name"}}</label>
+					<input id="application-name" value="{{.App.Name}}" name="application_name" required>
+				</div>
+				<div class="field {{if .Err_RedirectURI}}error{{end}}">
+					<label for="redirect-uri">{{.i18n.Tr "settings.oauth2_redirect_uri"}}</label>
+					<input type="url" name="redirect_uri" value="{{.App.PrimaryRedirectURI}}" id="redirect-uri">
+				</div>
+				<button class="ui green button">
+					{{.i18n.Tr "settings.save_application"}}
+				</button>
+			</form>
+		</div>
+	</div>
+</div>
+
+<div class="ui small basic delete modal" id="delete-oauth2-application">
+	<div class="ui icon header">
+		<i class="trash icon"></i>
+		{{.i18n.Tr "settings.remove_oauth2_application"}}
+	</div>
+	<div class="content">
+		<p>{{.i18n.Tr "settings.remove_oauth2_application_desc"}}</p>
+	</div>
+	{{template "base/delete_modal_actions" .}}
+</div>
+
+{{template "base/footer" .}}

vendor/golang.org/x/crypto/bcrypt/base64.go

@@ -0,0 +1,35 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bcrypt
+
+import "encoding/base64"
+
+const alphabet = "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+
+var bcEncoding = base64.NewEncoding(alphabet)
+
+func base64Encode(src []byte) []byte {
+	n := bcEncoding.EncodedLen(len(src))
+	dst := make([]byte, n)
+	bcEncoding.Encode(dst, src)
+	for dst[n-1] == '=' {
+		n--
+	}
+	return dst[:n]
+}
+
+func base64Decode(src []byte) ([]byte, error) {
+	numOfEquals := 4 - (len(src) % 4)
+	for i := 0; i < numOfEquals; i++ {
+		src = append(src, '=')
+	}
+
+	dst := make([]byte, bcEncoding.DecodedLen(len(src)))
+	n, err := bcEncoding.Decode(dst, src)
+	if err != nil {
+		return nil, err
+	}
+	return dst[:n], nil
+}

vendor/golang.org/x/crypto/bcrypt/bcrypt.go

@@ -0,0 +1,295 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package bcrypt implements Provos and Mazières's bcrypt adaptive hashing
+// algorithm. See http://www.usenix.org/event/usenix99/provos/provos.pdf
+package bcrypt // import "golang.org/x/crypto/bcrypt"
+
+// The code is a port of Provos and Mazières's C implementation.
+import (
+	"crypto/rand"
+	"crypto/subtle"
+	"errors"
+	"fmt"
+	"io"
+	"strconv"
+
+	"golang.org/x/crypto/blowfish"
+)
+
+const (
+	MinCost     int = 4  // the minimum allowable cost as passed in to GenerateFromPassword
+	MaxCost     int = 31 // the maximum allowable cost as passed in to GenerateFromPassword
+	DefaultCost int = 10 // the cost that will actually be set if a cost below MinCost is passed into GenerateFromPassword
+)
+
+// The error returned from CompareHashAndPassword when a password and hash do
+// not match.
+var ErrMismatchedHashAndPassword = errors.New("crypto/bcrypt: hashedPassword is not the hash of the given password")
+
+// The error returned from CompareHashAndPassword when a hash is too short to
+// be a bcrypt hash.
+var ErrHashTooShort = errors.New("crypto/bcrypt: hashedSecret too short to be a bcrypted password")
+
+// The error returned from CompareHashAndPassword when a hash was created with
+// a bcrypt algorithm newer than this implementation.
+type HashVersionTooNewError byte
+
+func (hv HashVersionTooNewError) Error() string {
+	return fmt.Sprintf("crypto/bcrypt: bcrypt algorithm version '%c' requested is newer than current version '%c'", byte(hv), majorVersion)
+}
+
+// The error returned from CompareHashAndPassword when a hash starts with something other than '$'
+type InvalidHashPrefixError byte
+
+func (ih InvalidHashPrefixError) Error() string {
+	return fmt.Sprintf("crypto/bcrypt: bcrypt hashes must start with '$', but hashedSecret started with '%c'", byte(ih))
+}
+
+type InvalidCostError int
+
+func (ic InvalidCostError) Error() string {
+	return fmt.Sprintf("crypto/bcrypt: cost %d is outside allowed range (%d,%d)", int(ic), int(MinCost), int(MaxCost))
+}
+
+const (
+	majorVersion       = '2'
+	minorVersion       = 'a'
+	maxSaltSize        = 16
+	maxCryptedHashSize = 23
+	encodedSaltSize    = 22
+	encodedHashSize    = 31
+	minHashSize        = 59
+)
+
+// magicCipherData is an IV for the 64 Blowfish encryption calls in
+// bcrypt(). It's the string "OrpheanBeholderScryDoubt" in big-endian bytes.
+var magicCipherData = []byte{
+	0x4f, 0x72, 0x70, 0x68,
+	0x65, 0x61, 0x6e, 0x42,
+	0x65, 0x68, 0x6f, 0x6c,
+	0x64, 0x65, 0x72, 0x53,
+	0x63, 0x72, 0x79, 0x44,
+	0x6f, 0x75, 0x62, 0x74,
+}
+
+type hashed struct {
+	hash  []byte
+	salt  []byte
+	cost  int // allowed range is MinCost to MaxCost
+	major byte
+	minor byte
+}
+
+// GenerateFromPassword returns the bcrypt hash of the password at the given
+// cost. If the cost given is less than MinCost, the cost will be set to
+// DefaultCost, instead. Use CompareHashAndPassword, as defined in this package,
+// to compare the returned hashed password with its cleartext version.
+func GenerateFromPassword(password []byte, cost int) ([]byte, error) {
+	p, err := newFromPassword(password, cost)
+	if err != nil {
+		return nil, err
+	}
+	return p.Hash(), nil
+}
+
+// CompareHashAndPassword compares a bcrypt hashed password with its possible
+// plaintext equivalent. Returns nil on success, or an error on failure.
+func CompareHashAndPassword(hashedPassword, password []byte) error {
+	p, err := newFromHash(hashedPassword)
+	if err != nil {
+		return err
+	}
+
+	otherHash, err := bcrypt(password, p.cost, p.salt)
+	if err != nil {
+		return err
+	}
+
+	otherP := &hashed{otherHash, p.salt, p.cost, p.major, p.minor}
+	if subtle.ConstantTimeCompare(p.Hash(), otherP.Hash()) == 1 {
+		return nil
+	}
+
+	return ErrMismatchedHashAndPassword
+}
+
+// Cost returns the hashing cost used to create the given hashed
+// password. When, in the future, the hashing cost of a password system needs
+// to be increased in order to adjust for greater computational power, this
+// function allows one to establish which passwords need to be updated.
+func Cost(hashedPassword []byte) (int, error) {
+	p, err := newFromHash(hashedPassword)
+	if err != nil {
+		return 0, err
+	}
+	return p.cost, nil
+}
+
+func newFromPassword(password []byte, cost int) (*hashed, error) {
+	if cost < MinCost {
+		cost = DefaultCost
+	}
+	p := new(hashed)
+	p.major = majorVersion
+	p.minor = minorVersion
+
+	err := checkCost(cost)
+	if err != nil {
+		return nil, err
+	}
+	p.cost = cost
+
+	unencodedSalt := make([]byte, maxSaltSize)
+	_, err = io.ReadFull(rand.Reader, unencodedSalt)
+	if err != nil {
+		return nil, err
+	}
+
+	p.salt = base64Encode(unencodedSalt)
+	hash, err := bcrypt(password, p.cost, p.salt)
+	if err != nil {
+		return nil, err
+	}
+	p.hash = hash
+	return p, err
+}
+
+func newFromHash(hashedSecret []byte) (*hashed, error) {
+	if len(hashedSecret) < minHashSize {
+		return nil, ErrHashTooShort
+	}
+	p := new(hashed)
+	n, err := p.decodeVersion(hashedSecret)
+	if err != nil {
+		return nil, err
+	}
+	hashedSecret = hashedSecret[n:]
+	n, err = p.decodeCost(hashedSecret)
+	if err != nil {
+		return nil, err
+	}
+	hashedSecret = hashedSecret[n:]
+
+	// The "+2" is here because we'll have to append at most 2 '=' to the salt
+	// when base64 decoding it in expensiveBlowfishSetup().
+	p.salt = make([]byte, encodedSaltSize, encodedSaltSize+2)
+	copy(p.salt, hashedSecret[:encodedSaltSize])
+
+	hashedSecret = hashedSecret[encodedSaltSize:]
+	p.hash = make([]byte, len(hashedSecret))
+	copy(p.hash, hashedSecret)
+
+	return p, nil
+}
+
+func bcrypt(password []byte, cost int, salt []byte) ([]byte, error) {
+	cipherData := make([]byte, len(magicCipherData))
+	copy(cipherData, magicCipherData)
+
+	c, err := expensiveBlowfishSetup(password, uint32(cost), salt)
+	if err != nil {
+		return nil, err
+	}
+
+	for i := 0; i < 24; i += 8 {
+		for j := 0; j < 64; j++ {
+			c.Encrypt(cipherData[i:i+8], cipherData[i:i+8])
+		}
+	}
+
+	// Bug compatibility with C bcrypt implementations. We only encode 23 of
+	// the 24 bytes encrypted.
+	hsh := base64Encode(cipherData[:maxCryptedHashSize])
+	return hsh, nil
+}
+
+func expensiveBlowfishSetup(key []byte, cost uint32, salt []byte) (*blowfish.Cipher, error) {
+	csalt, err := base64Decode(salt)
+	if err != nil {
+		return nil, err
+	}
+
+	// Bug compatibility with C bcrypt implementations. They use the trailing
+	// NULL in the key string during expansion.
+	// We copy the key to prevent changing the underlying array.
+	ckey := append(key[:len(key):len(key)], 0)
+
+	c, err := blowfish.NewSaltedCipher(ckey, csalt)
+	if err != nil {
+		return nil, err
+	}
+
+	var i, rounds uint64
+	rounds = 1 << cost
+	for i = 0; i < rounds; i++ {
+		blowfish.ExpandKey(ckey, c)
+		blowfish.ExpandKey(csalt, c)
+	}
+
+	return c, nil
+}
+
+func (p *hashed) Hash() []byte {
+	arr := make([]byte, 60)
+	arr[0] = '$'
+	arr[1] = p.major
+	n := 2
+	if p.minor != 0 {
+		arr[2] = p.minor
+		n = 3
+	}
+	arr[n] = '$'
+	n++
+	copy(arr[n:], []byte(fmt.Sprintf("%02d", p.cost)))
+	n += 2
+	arr[n] = '$'
+	n++
+	copy(arr[n:], p.salt)
+	n += encodedSaltSize
+	copy(arr[n:], p.hash)
+	n += encodedHashSize
+	return arr[:n]
+}
+
+func (p *hashed) decodeVersion(sbytes []byte) (int, error) {
+	if sbytes[0] != '$' {
+		return -1, InvalidHashPrefixError(sbytes[0])
+	}
+	if sbytes[1] > majorVersion {
+		return -1, HashVersionTooNewError(sbytes[1])
+	}
+	p.major = sbytes[1]
+	n := 3
+	if sbytes[2] != '$' {
+		p.minor = sbytes[2]
+		n++
+	}
+	return n, nil
+}
+
+// sbytes should begin where decodeVersion left off.
+func (p *hashed) decodeCost(sbytes []byte) (int, error) {
+	cost, err := strconv.Atoi(string(sbytes[0:2]))
+	if err != nil {
+		return -1, err
+	}
+	err = checkCost(cost)
+	if err != nil {
+		return -1, err
+	}
+	p.cost = cost
+	return 3, nil
+}
+
+func (p *hashed) String() string {
+	return fmt.Sprintf("&{hash: %#v, salt: %#v, cost: %d, major: %c, minor: %c}", string(p.hash), p.salt, p.cost, p.major, p.minor)
+}
+
+func checkCost(cost int) error {
+	if cost < MinCost || cost > MaxCost {
+		return InvalidCostError(cost)
+	}
+	return nil
+}

vendor/golang.org/x/crypto/blowfish/block.go

@@ -0,0 +1,159 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package blowfish
+
+// getNextWord returns the next big-endian uint32 value from the byte slice
+// at the given position in a circular manner, updating the position.
+func getNextWord(b []byte, pos *int) uint32 {
+	var w uint32
+	j := *pos
+	for i := 0; i < 4; i++ {
+		w = w<<8 | uint32(b[j])
+		j++
+		if j >= len(b) {
+			j = 0
+		}
+	}
+	*pos = j
+	return w
+}
+
+// ExpandKey performs a key expansion on the given *Cipher. Specifically, it
+// performs the Blowfish algorithm's key schedule which sets up the *Cipher's
+// pi and substitution tables for calls to Encrypt. This is used, primarily,
+// by the bcrypt package to reuse the Blowfish key schedule during its
+// set up. It's unlikely that you need to use this directly.
+func ExpandKey(key []byte, c *Cipher) {
+	j := 0
+	for i := 0; i < 18; i++ {
+		// Using inlined getNextWord for performance.
+		var d uint32
+		for k := 0; k < 4; k++ {
+			d = d<<8 | uint32(key[j])
+			j++
+			if j >= len(key) {
+				j = 0
+			}
+		}
+		c.p[i] ^= d
+	}
+
+	var l, r uint32
+	for i := 0; i < 18; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.p[i], c.p[i+1] = l, r
+	}
+
+	for i := 0; i < 256; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.s0[i], c.s0[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.s1[i], c.s1[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.s2[i], c.s2[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.s3[i], c.s3[i+1] = l, r
+	}
+}
+
+// This is similar to ExpandKey, but folds the salt during the key
+// schedule. While ExpandKey is essentially expandKeyWithSalt with an all-zero
+// salt passed in, reusing ExpandKey turns out to be a place of inefficiency
+// and specializing it here is useful.
+func expandKeyWithSalt(key []byte, salt []byte, c *Cipher) {
+	j := 0
+	for i := 0; i < 18; i++ {
+		c.p[i] ^= getNextWord(key, &j)
+	}
+
+	j = 0
+	var l, r uint32
+	for i := 0; i < 18; i += 2 {
+		l ^= getNextWord(salt, &j)
+		r ^= getNextWord(salt, &j)
+		l, r = encryptBlock(l, r, c)
+		c.p[i], c.p[i+1] = l, r
+	}
+
+	for i := 0; i < 256; i += 2 {
+		l ^= getNextWord(salt, &j)
+		r ^= getNextWord(salt, &j)
+		l, r = encryptBlock(l, r, c)
+		c.s0[i], c.s0[i+1] = l, r
+	}
+
+	for i := 0; i < 256; i += 2 {
+		l ^= getNextWord(salt, &j)
+		r ^= getNextWord(salt, &j)
+		l, r = encryptBlock(l, r, c)
+		c.s1[i], c.s1[i+1] = l, r
+	}
+
+	for i := 0; i < 256; i += 2 {
+		l ^= getNextWord(salt, &j)
+		r ^= getNextWord(salt, &j)
+		l, r = encryptBlock(l, r, c)
+		c.s2[i], c.s2[i+1] = l, r
+	}
+
+	for i := 0; i < 256; i += 2 {
+		l ^= getNextWord(salt, &j)
+		r ^= getNextWord(salt, &j)
+		l, r = encryptBlock(l, r, c)
+		c.s3[i], c.s3[i+1] = l, r
+	}
+}
+
+func encryptBlock(l, r uint32, c *Cipher) (uint32, uint32) {
+	xl, xr := l, r
+	xl ^= c.p[0]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[1]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[2]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[3]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[4]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[5]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[6]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[7]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[8]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[9]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[10]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[11]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[12]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[13]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[14]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[15]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[16]
+	xr ^= c.p[17]
+	return xr, xl
+}
+
+func decryptBlock(l, r uint32, c *Cipher) (uint32, uint32) {
+	xl, xr := l, r
+	xl ^= c.p[17]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[16]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[15]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[14]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[13]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[12]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[11]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[10]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[9]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[8]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[7]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[6]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[5]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[4]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[3]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[2]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[1]
+	xr ^= c.p[0]
+	return xr, xl
+}

vendor/golang.org/x/crypto/blowfish/cipher.go

@@ -0,0 +1,91 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package blowfish implements Bruce Schneier's Blowfish encryption algorithm.
+package blowfish // import "golang.org/x/crypto/blowfish"
+
+// The code is a port of Bruce Schneier's C implementation.
+// See https://www.schneier.com/blowfish.html.
+
+import "strconv"
+
+// The Blowfish block size in bytes.
+const BlockSize = 8
+
+// A Cipher is an instance of Blowfish encryption using a particular key.
+type Cipher struct {
+	p              [18]uint32
+	s0, s1, s2, s3 [256]uint32
+}
+
+type KeySizeError int
+
+func (k KeySizeError) Error() string {
+	return "crypto/blowfish: invalid key size " + strconv.Itoa(int(k))
+}
+
+// NewCipher creates and returns a Cipher.
+// The key argument should be the Blowfish key, from 1 to 56 bytes.
+func NewCipher(key []byte) (*Cipher, error) {
+	var result Cipher
+	if k := len(key); k < 1 || k > 56 {
+		return nil, KeySizeError(k)
+	}
+	initCipher(&result)
+	ExpandKey(key, &result)
+	return &result, nil
+}
+
+// NewSaltedCipher creates a returns a Cipher that folds a salt into its key
+// schedule. For most purposes, NewCipher, instead of NewSaltedCipher, is
+// sufficient and desirable. For bcrypt compatibility, the key can be over 56
+// bytes.
+func NewSaltedCipher(key, salt []byte) (*Cipher, error) {
+	if len(salt) == 0 {
+		return NewCipher(key)
+	}
+	var result Cipher
+	if k := len(key); k < 1 {
+		return nil, KeySizeError(k)
+	}
+	initCipher(&result)
+	expandKeyWithSalt(key, salt, &result)
+	return &result, nil
+}
+
+// BlockSize returns the Blowfish block size, 8 bytes.
+// It is necessary to satisfy the Block interface in the
+// package "crypto/cipher".
+func (c *Cipher) BlockSize() int { return BlockSize }
+
+// Encrypt encrypts the 8-byte buffer src using the key k
+// and stores the result in dst.
+// Note that for amounts of data larger than a block,
+// it is not safe to just call Encrypt on successive blocks;
+// instead, use an encryption mode like CBC (see crypto/cipher/cbc.go).
+func (c *Cipher) Encrypt(dst, src []byte) {
+	l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
+	r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
+	l, r = encryptBlock(l, r, c)
+	dst[0], dst[1], dst[2], dst[3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
+	dst[4], dst[5], dst[6], dst[7] = byte(r>>24), byte(r>>16), byte(r>>8), byte(r)
+}
+
+// Decrypt decrypts the 8-byte buffer src using the key k
+// and stores the result in dst.
+func (c *Cipher) Decrypt(dst, src []byte) {
+	l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
+	r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
+	l, r = decryptBlock(l, r, c)
+	dst[0], dst[1], dst[2], dst[3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
+	dst[4], dst[5], dst[6], dst[7] = byte(r>>24), byte(r>>16), byte(r>>8), byte(r)
+}
+
+func initCipher(c *Cipher) {
+	copy(c.p[0:], p[0:])
+	copy(c.s0[0:], s0[0:])
+	copy(c.s1[0:], s1[0:])
+	copy(c.s2[0:], s2[0:])
+	copy(c.s3[0:], s3[0:])
+}

vendor/golang.org/x/crypto/blowfish/const.go

@@ -0,0 +1,199 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The startup permutation array and substitution boxes.
+// They are the hexadecimal digits of PI; see:
+// https://www.schneier.com/code/constants.txt.
+
+package blowfish
+
+var s0 = [256]uint32{
+	0xd1310ba6, 0x98dfb5ac, 0x2ffd72db, 0xd01adfb7, 0xb8e1afed, 0x6a267e96,
+	0xba7c9045, 0xf12c7f99, 0x24a19947, 0xb3916cf7, 0x0801f2e2, 0x858efc16,
+	0x636920d8, 0x71574e69, 0xa458fea3, 0xf4933d7e, 0x0d95748f, 0x728eb658,
+	0x718bcd58, 0x82154aee, 0x7b54a41d, 0xc25a59b5, 0x9c30d539, 0x2af26013,
+	0xc5d1b023, 0x286085f0, 0xca417918, 0xb8db38ef, 0x8e79dcb0, 0x603a180e,
+	0x6c9e0e8b, 0xb01e8a3e, 0xd71577c1, 0xbd314b27, 0x78af2fda, 0x55605c60,
+	0xe65525f3, 0xaa55ab94, 0x57489862, 0x63e81440, 0x55ca396a, 0x2aab10b6,
+	0xb4cc5c34, 0x1141e8ce, 0xa15486af, 0x7c72e993, 0xb3ee1411, 0x636fbc2a,
+	0x2ba9c55d, 0x741831f6, 0xce5c3e16, 0x9b87931e, 0xafd6ba33, 0x6c24cf5c,
+	0x7a325381, 0x28958677, 0x3b8f4898, 0x6b4bb9af, 0xc4bfe81b, 0x66282193,
+	0x61d809cc, 0xfb21a991, 0x487cac60, 0x5dec8032, 0xef845d5d, 0xe98575b1,
+	0xdc262302, 0xeb651b88, 0x23893e81, 0xd396acc5, 0x0f6d6ff3, 0x83f44239,
+	0x2e0b4482, 0xa4842004, 0x69c8f04a, 0x9e1f9b5e, 0x21c66842, 0xf6e96c9a,
+	0x670c9c61, 0xabd388f0, 0x6a51a0d2, 0xd8542f68, 0x960fa728, 0xab5133a3,
+	0x6eef0b6c, 0x137a3be4, 0xba3bf050, 0x7efb2a98, 0xa1f1651d, 0x39af0176,
+	0x66ca593e, 0x82430e88, 0x8cee8619, 0x456f9fb4, 0x7d84a5c3, 0x3b8b5ebe,
+	0xe06f75d8, 0x85c12073, 0x401a449f, 0x56c16aa6, 0x4ed3aa62, 0x363f7706,
+	0x1bfedf72, 0x429b023d, 0x37d0d724, 0xd00a1248, 0xdb0fead3, 0x49f1c09b,
+	0x075372c9, 0x80991b7b, 0x25d479d8, 0xf6e8def7, 0xe3fe501a, 0xb6794c3b,
+	0x976ce0bd, 0x04c006ba, 0xc1a94fb6, 0x409f60c4, 0x5e5c9ec2, 0x196a2463,
+	0x68fb6faf, 0x3e6c53b5, 0x1339b2eb, 0x3b52ec6f, 0x6dfc511f, 0x9b30952c,
+	0xcc814544, 0xaf5ebd09, 0xbee3d004, 0xde334afd, 0x660f2807, 0x192e4bb3,
+	0xc0cba857, 0x45c8740f, 0xd20b5f39, 0xb9d3fbdb, 0x5579c0bd, 0x1a60320a,
+	0xd6a100c6, 0x402c7279, 0x679f25fe, 0xfb1fa3cc, 0x8ea5e9f8, 0xdb3222f8,
+	0x3c7516df, 0xfd616b15, 0x2f501ec8, 0xad0552ab, 0x323db5fa, 0xfd238760,
+	0x53317b48, 0x3e00df82, 0x9e5c57bb, 0xca6f8ca0, 0x1a87562e, 0xdf1769db,
+	0xd542a8f6, 0x287effc3, 0xac6732c6, 0x8c4f5573, 0x695b27b0, 0xbbca58c8,
+	0xe1ffa35d, 0xb8f011a0, 0x10fa3d98, 0xfd2183b8, 0x4afcb56c, 0x2dd1d35b,
+	0x9a53e479, 0xb6f84565, 0xd28e49bc, 0x4bfb9790, 0xe1ddf2da, 0xa4cb7e33,
+	0x62fb1341, 0xcee4c6e8, 0xef20cada, 0x36774c01, 0xd07e9efe, 0x2bf11fb4,
+	0x95dbda4d, 0xae909198, 0xeaad8e71, 0x6b93d5a0, 0xd08ed1d0, 0xafc725e0,
+	0x8e3c5b2f, 0x8e7594b7, 0x8ff6e2fb, 0xf2122b64, 0x8888b812, 0x900df01c,
+	0x4fad5ea0, 0x688fc31c, 0xd1cff191, 0xb3a8c1ad, 0x2f2f2218, 0xbe0e1777,
+	0xea752dfe, 0x8b021fa1, 0xe5a0cc0f, 0xb56f74e8, 0x18acf3d6, 0xce89e299,
+	0xb4a84fe0, 0xfd13e0b7, 0x7cc43b81, 0xd2ada8d9, 0x165fa266, 0x80957705,
+	0x93cc7314, 0x211a1477, 0xe6ad2065, 0x77b5fa86, 0xc75442f5, 0xfb9d35cf,
+	0xebcdaf0c, 0x7b3e89a0, 0xd6411bd3, 0xae1e7e49, 0x00250e2d, 0x2071b35e,
+	0x226800bb, 0x57b8e0af, 0x2464369b, 0xf009b91e, 0x5563911d, 0x59dfa6aa,
+	0x78c14389, 0xd95a537f, 0x207d5ba2, 0x02e5b9c5, 0x83260376, 0x6295cfa9,
+	0x11c81968, 0x4e734a41, 0xb3472dca, 0x7b14a94a, 0x1b510052, 0x9a532915,
+	0xd60f573f, 0xbc9bc6e4, 0x2b60a476, 0x81e67400, 0x08ba6fb5, 0x571be91f,
+	0xf296ec6b, 0x2a0dd915, 0xb6636521, 0xe7b9f9b6, 0xff34052e, 0xc5855664,
+	0x53b02d5d, 0xa99f8fa1, 0x08ba4799, 0x6e85076a,
+}
+
+var s1 = [256]uint32{
+	0x4b7a70e9, 0xb5b32944, 0xdb75092e, 0xc4192623, 0xad6ea6b0, 0x49a7df7d,
+	0x9cee60b8, 0x8fedb266, 0xecaa8c71, 0x699a17ff, 0x5664526c, 0xc2b19ee1,
+	0x193602a5, 0x75094c29, 0xa0591340, 0xe4183a3e, 0x3f54989a, 0x5b429d65,
+	0x6b8fe4d6, 0x99f73fd6, 0xa1d29c07, 0xefe830f5, 0x4d2d38e6, 0xf0255dc1,
+	0x4cdd2086, 0x8470eb26, 0x6382e9c6, 0x021ecc5e, 0x09686b3f, 0x3ebaefc9,
+	0x3c971814, 0x6b6a70a1, 0x687f3584, 0x52a0e286, 0xb79c5305, 0xaa500737,
+	0x3e07841c, 0x7fdeae5c, 0x8e7d44ec, 0x5716f2b8, 0xb03ada37, 0xf0500c0d,
+	0xf01c1f04, 0x0200b3ff, 0xae0cf51a, 0x3cb574b2, 0x25837a58, 0xdc0921bd,
+	0xd19113f9, 0x7ca92ff6, 0x94324773, 0x22f54701, 0x3ae5e581, 0x37c2dadc,
+	0xc8b57634, 0x9af3dda7, 0xa9446146, 0x0fd0030e, 0xecc8c73e, 0xa4751e41,
+	0xe238cd99, 0x3bea0e2f, 0x3280bba1, 0x183eb331, 0x4e548b38, 0x4f6db908,
+	0x6f420d03, 0xf60a04bf, 0x2cb81290, 0x24977c79, 0x5679b072, 0xbcaf89af,
+	0xde9a771f, 0xd9930810, 0xb38bae12, 0xdccf3f2e, 0x5512721f, 0x2e6b7124,
+	0x501adde6, 0x9f84cd87, 0x7a584718, 0x7408da17, 0xbc9f9abc, 0xe94b7d8c,
+	0xec7aec3a, 0xdb851dfa, 0x63094366, 0xc464c3d2, 0xef1c1847, 0x3215d908,
+	0xdd433b37, 0x24c2ba16, 0x12a14d43, 0x2a65c451, 0x50940002, 0x133ae4dd,
+	0x71dff89e, 0x10314e55, 0x81ac77d6, 0x5f11199b, 0x043556f1, 0xd7a3c76b,
+	0x3c11183b, 0x5924a509, 0xf28fe6ed, 0x97f1fbfa, 0x9ebabf2c, 0x1e153c6e,
+	0x86e34570, 0xeae96fb1, 0x860e5e0a, 0x5a3e2ab3, 0x771fe71c, 0x4e3d06fa,
+	0x2965dcb9, 0x99e71d0f, 0x803e89d6, 0x5266c825, 0x2e4cc978, 0x9c10b36a,
+	0xc6150eba, 0x94e2ea78, 0xa5fc3c53, 0x1e0a2df4, 0xf2f74ea7, 0x361d2b3d,
+	0x1939260f, 0x19c27960, 0x5223a708, 0xf71312b6, 0xebadfe6e, 0xeac31f66,
+	0xe3bc4595, 0xa67bc883, 0xb17f37d1, 0x018cff28, 0xc332ddef, 0xbe6c5aa5,
+	0x65582185, 0x68ab9802, 0xeecea50f, 0xdb2f953b, 0x2aef7dad, 0x5b6e2f84,
+	0x1521b628, 0x29076170, 0xecdd4775, 0x619f1510, 0x13cca830, 0xeb61bd96,
+	0x0334fe1e, 0xaa0363cf, 0xb5735c90, 0x4c70a239, 0xd59e9e0b, 0xcbaade14,
+	0xeecc86bc, 0x60622ca7, 0x9cab5cab, 0xb2f3846e, 0x648b1eaf, 0x19bdf0ca,
+	0xa02369b9, 0x655abb50, 0x40685a32, 0x3c2ab4b3, 0x319ee9d5, 0xc021b8f7,
+	0x9b540b19, 0x875fa099, 0x95f7997e, 0x623d7da8, 0xf837889a, 0x97e32d77,
+	0x11ed935f, 0x16681281, 0x0e358829, 0xc7e61fd6, 0x96dedfa1, 0x7858ba99,
+	0x57f584a5, 0x1b227263, 0x9b83c3ff, 0x1ac24696, 0xcdb30aeb, 0x532e3054,
+	0x8fd948e4, 0x6dbc3128, 0x58ebf2ef, 0x34c6ffea, 0xfe28ed61, 0xee7c3c73,
+	0x5d4a14d9, 0xe864b7e3, 0x42105d14, 0x203e13e0, 0x45eee2b6, 0xa3aaabea,
+	0xdb6c4f15, 0xfacb4fd0, 0xc742f442, 0xef6abbb5, 0x654f3b1d, 0x41cd2105,
+	0xd81e799e, 0x86854dc7, 0xe44b476a, 0x3d816250, 0xcf62a1f2, 0x5b8d2646,
+	0xfc8883a0, 0xc1c7b6a3, 0x7f1524c3, 0x69cb7492, 0x47848a0b, 0x5692b285,
+	0x095bbf00, 0xad19489d, 0x1462b174, 0x23820e00, 0x58428d2a, 0x0c55f5ea,
+	0x1dadf43e, 0x233f7061, 0x3372f092, 0x8d937e41, 0xd65fecf1, 0x6c223bdb,
+	0x7cde3759, 0xcbee7460, 0x4085f2a7, 0xce77326e, 0xa6078084, 0x19f8509e,
+	0xe8efd855, 0x61d99735, 0xa969a7aa, 0xc50c06c2, 0x5a04abfc, 0x800bcadc,
+	0x9e447a2e, 0xc3453484, 0xfdd56705, 0x0e1e9ec9, 0xdb73dbd3, 0x105588cd,
+	0x675fda79, 0xe3674340, 0xc5c43465, 0x713e38d8, 0x3d28f89e, 0xf16dff20,
+	0x153e21e7, 0x8fb03d4a, 0xe6e39f2b, 0xdb83adf7,
+}
+
+var s2 = [256]uint32{
+	0xe93d5a68, 0x948140f7, 0xf64c261c, 0x94692934, 0x411520f7, 0x7602d4f7,
+	0xbcf46b2e, 0xd4a20068, 0xd4082471, 0x3320f46a, 0x43b7d4b7, 0x500061af,
+	0x1e39f62e, 0x97244546, 0x14214f74, 0xbf8b8840, 0x4d95fc1d, 0x96b591af,
+	0x70f4ddd3, 0x66a02f45, 0xbfbc09ec, 0x03bd9785, 0x7fac6dd0, 0x31cb8504,
+	0x96eb27b3, 0x55fd3941, 0xda2547e6, 0xabca0a9a, 0x28507825, 0x530429f4,
+	0x0a2c86da, 0xe9b66dfb, 0x68dc1462, 0xd7486900, 0x680ec0a4, 0x27a18dee,
+	0x4f3ffea2, 0xe887ad8c, 0xb58ce006, 0x7af4d6b6, 0xaace1e7c, 0xd3375fec,
+	0xce78a399, 0x406b2a42, 0x20fe9e35, 0xd9f385b9, 0xee39d7ab, 0x3b124e8b,
+	0x1dc9faf7, 0x4b6d1856, 0x26a36631, 0xeae397b2, 0x3a6efa74, 0xdd5b4332,
+	0x6841e7f7, 0xca7820fb, 0xfb0af54e, 0xd8feb397, 0x454056ac, 0xba489527,
+	0x55533a3a, 0x20838d87, 0xfe6ba9b7, 0xd096954b, 0x55a867bc, 0xa1159a58,
+	0xcca92963, 0x99e1db33, 0xa62a4a56, 0x3f3125f9, 0x5ef47e1c, 0x9029317c,
+	0xfdf8e802, 0x04272f70, 0x80bb155c, 0x05282ce3, 0x95c11548, 0xe4c66d22,
+	0x48c1133f, 0xc70f86dc, 0x07f9c9ee, 0x41041f0f, 0x404779a4, 0x5d886e17,
+	0x325f51eb, 0xd59bc0d1, 0xf2bcc18f, 0x41113564, 0x257b7834, 0x602a9c60,
+	0xdff8e8a3, 0x1f636c1b, 0x0e12b4c2, 0x02e1329e, 0xaf664fd1, 0xcad18115,
+	0x6b2395e0, 0x333e92e1, 0x3b240b62, 0xeebeb922, 0x85b2a20e, 0xe6ba0d99,
+	0xde720c8c, 0x2da2f728, 0xd0127845, 0x95b794fd, 0x647d0862, 0xe7ccf5f0,
+	0x5449a36f, 0x877d48fa, 0xc39dfd27, 0xf33e8d1e, 0x0a476341, 0x992eff74,
+	0x3a6f6eab, 0xf4f8fd37, 0xa812dc60, 0xa1ebddf8, 0x991be14c, 0xdb6e6b0d,
+	0xc67b5510, 0x6d672c37, 0x2765d43b, 0xdcd0e804, 0xf1290dc7, 0xcc00ffa3,
+	0xb5390f92, 0x690fed0b, 0x667b9ffb, 0xcedb7d9c, 0xa091cf0b, 0xd9155ea3,
+	0xbb132f88, 0x515bad24, 0x7b9479bf, 0x763bd6eb, 0x37392eb3, 0xcc115979,
+	0x8026e297, 0xf42e312d, 0x6842ada7, 0xc66a2b3b, 0x12754ccc, 0x782ef11c,
+	0x6a124237, 0xb79251e7, 0x06a1bbe6, 0x4bfb6350, 0x1a6b1018, 0x11caedfa,
+	0x3d25bdd8, 0xe2e1c3c9, 0x44421659, 0x0a121386, 0xd90cec6e, 0xd5abea2a,
+	0x64af674e, 0xda86a85f, 0xbebfe988, 0x64e4c3fe, 0x9dbc8057, 0xf0f7c086,
+	0x60787bf8, 0x6003604d, 0xd1fd8346, 0xf6381fb0, 0x7745ae04, 0xd736fccc,
+	0x83426b33, 0xf01eab71, 0xb0804187, 0x3c005e5f, 0x77a057be, 0xbde8ae24,
+	0x55464299, 0xbf582e61, 0x4e58f48f, 0xf2ddfda2, 0xf474ef38, 0x8789bdc2,
+	0x5366f9c3, 0xc8b38e74, 0xb475f255, 0x46fcd9b9, 0x7aeb2661, 0x8b1ddf84,
+	0x846a0e79, 0x915f95e2, 0x466e598e, 0x20b45770, 0x8cd55591, 0xc902de4c,
+	0xb90bace1, 0xbb8205d0, 0x11a86248, 0x7574a99e, 0xb77f19b6, 0xe0a9dc09,
+	0x662d09a1, 0xc4324633, 0xe85a1f02, 0x09f0be8c, 0x4a99a025, 0x1d6efe10,
+	0x1ab93d1d, 0x0ba5a4df, 0xa186f20f, 0x2868f169, 0xdcb7da83, 0x573906fe,
+	0xa1e2ce9b, 0x4fcd7f52, 0x50115e01, 0xa70683fa, 0xa002b5c4, 0x0de6d027,
+	0x9af88c27, 0x773f8641, 0xc3604c06, 0x61a806b5, 0xf0177a28, 0xc0f586e0,
+	0x006058aa, 0x30dc7d62, 0x11e69ed7, 0x2338ea63, 0x53c2dd94, 0xc2c21634,
+	0xbbcbee56, 0x90bcb6de, 0xebfc7da1, 0xce591d76, 0x6f05e409, 0x4b7c0188,
+	0x39720a3d, 0x7c927c24, 0x86e3725f, 0x724d9db9, 0x1ac15bb4, 0xd39eb8fc,
+	0xed545578, 0x08fca5b5, 0xd83d7cd3, 0x4dad0fc4, 0x1e50ef5e, 0xb161e6f8,
+	0xa28514d9, 0x6c51133c, 0x6fd5c7e7, 0x56e14ec4, 0x362abfce, 0xddc6c837,
+	0xd79a3234, 0x92638212, 0x670efa8e, 0x406000e0,
+}
+
+var s3 = [256]uint32{
+	0x3a39ce37, 0xd3faf5cf, 0xabc27737, 0x5ac52d1b, 0x5cb0679e, 0x4fa33742,
+	0xd3822740, 0x99bc9bbe, 0xd5118e9d, 0xbf0f7315, 0xd62d1c7e, 0xc700c47b,
+	0xb78c1b6b, 0x21a19045, 0xb26eb1be, 0x6a366eb4, 0x5748ab2f, 0xbc946e79,
+	0xc6a376d2, 0x6549c2c8, 0x530ff8ee, 0x468dde7d, 0xd5730a1d, 0x4cd04dc6,
+	0x2939bbdb, 0xa9ba4650, 0xac9526e8, 0xbe5ee304, 0xa1fad5f0, 0x6a2d519a,
+	0x63ef8ce2, 0x9a86ee22, 0xc089c2b8, 0x43242ef6, 0xa51e03aa, 0x9cf2d0a4,
+	0x83c061ba, 0x9be96a4d, 0x8fe51550, 0xba645bd6, 0x2826a2f9, 0xa73a3ae1,
+	0x4ba99586, 0xef5562e9, 0xc72fefd3, 0xf752f7da, 0x3f046f69, 0x77fa0a59,
+	0x80e4a915, 0x87b08601, 0x9b09e6ad, 0x3b3ee593, 0xe990fd5a, 0x9e34d797,
+	0x2cf0b7d9, 0x022b8b51, 0x96d5ac3a, 0x017da67d, 0xd1cf3ed6, 0x7c7d2d28,
+	0x1f9f25cf, 0xadf2b89b, 0x5ad6b472, 0x5a88f54c, 0xe029ac71, 0xe019a5e6,
+	0x47b0acfd, 0xed93fa9b, 0xe8d3c48d, 0x283b57cc, 0xf8d56629, 0x79132e28,
+	0x785f0191, 0xed756055, 0xf7960e44, 0xe3d35e8c, 0x15056dd4, 0x88f46dba,
+	0x03a16125, 0x0564f0bd, 0xc3eb9e15, 0x3c9057a2, 0x97271aec, 0xa93a072a,
+	0x1b3f6d9b, 0x1e6321f5, 0xf59c66fb, 0x26dcf319, 0x7533d928, 0xb155fdf5,
+	0x03563482, 0x8aba3cbb, 0x28517711, 0xc20ad9f8, 0xabcc5167, 0xccad925f,
+	0x4de81751, 0x3830dc8e, 0x379d5862, 0x9320f991, 0xea7a90c2, 0xfb3e7bce,
+	0x5121ce64, 0x774fbe32, 0xa8b6e37e, 0xc3293d46, 0x48de5369, 0x6413e680,
+	0xa2ae0810, 0xdd6db224, 0x69852dfd, 0x09072166, 0xb39a460a, 0x6445c0dd,
+	0x586cdecf, 0x1c20c8ae, 0x5bbef7dd, 0x1b588d40, 0xccd2017f, 0x6bb4e3bb,
+	0xdda26a7e, 0x3a59ff45, 0x3e350a44, 0xbcb4cdd5, 0x72eacea8, 0xfa6484bb,
+	0x8d6612ae, 0xbf3c6f47, 0xd29be463, 0x542f5d9e, 0xaec2771b, 0xf64e6370,
+	0x740e0d8d, 0xe75b1357, 0xf8721671, 0xaf537d5d, 0x4040cb08, 0x4eb4e2cc,
+	0x34d2466a, 0x0115af84, 0xe1b00428, 0x95983a1d, 0x06b89fb4, 0xce6ea048,
+	0x6f3f3b82, 0x3520ab82, 0x011a1d4b, 0x277227f8, 0x611560b1, 0xe7933fdc,
+	0xbb3a792b, 0x344525bd, 0xa08839e1, 0x51ce794b, 0x2f32c9b7, 0xa01fbac9,
+	0xe01cc87e, 0xbcc7d1f6, 0xcf0111c3, 0xa1e8aac7, 0x1a908749, 0xd44fbd9a,
+	0xd0dadecb, 0xd50ada38, 0x0339c32a, 0xc6913667, 0x8df9317c, 0xe0b12b4f,
+	0xf79e59b7, 0x43f5bb3a, 0xf2d519ff, 0x27d9459c, 0xbf97222c, 0x15e6fc2a,
+	0x0f91fc71, 0x9b941525, 0xfae59361, 0xceb69ceb, 0xc2a86459, 0x12baa8d1,
+	0xb6c1075e, 0xe3056a0c, 0x10d25065, 0xcb03a442, 0xe0ec6e0e, 0x1698db3b,
+	0x4c98a0be, 0x3278e964, 0x9f1f9532, 0xe0d392df, 0xd3a0342b, 0x8971f21e,
+	0x1b0a7441, 0x4ba3348c, 0xc5be7120, 0xc37632d8, 0xdf359f8d, 0x9b992f2e,
+	0xe60b6f47, 0x0fe3f11d, 0xe54cda54, 0x1edad891, 0xce6279cf, 0xcd3e7e6f,
+	0x1618b166, 0xfd2c1d05, 0x848fd2c5, 0xf6fb2299, 0xf523f357, 0xa6327623,
+	0x93a83531, 0x56cccd02, 0xacf08162, 0x5a75ebb5, 0x6e163697, 0x88d273cc,
+	0xde966292, 0x81b949d0, 0x4c50901b, 0x71c65614, 0xe6c6c7bd, 0x327a140a,
+	0x45e1d006, 0xc3f27b9a, 0xc9aa53fd, 0x62a80f00, 0xbb25bfe2, 0x35bdd2f6,
+	0x71126905, 0xb2040222, 0xb6cbcf7c, 0xcd769c2b, 0x53113ec0, 0x1640e3d3,
+	0x38abbd60, 0x2547adf0, 0xba38209c, 0xf746ce76, 0x77afa1c5, 0x20756060,
+	0x85cbfe4e, 0x8ae88dd8, 0x7aaaf9b0, 0x4cf9aa7e, 0x1948c25c, 0x02fb8a8c,
+	0x01c36ae4, 0xd6ebe1f9, 0x90d4f869, 0xa65cdea0, 0x3f09252d, 0xc208e69f,
+	0xb74e6132, 0xce77e25b, 0x578fdfe3, 0x3ac372e6,
+}
+
+var p = [18]uint32{
+	0x243f6a88, 0x85a308d3, 0x13198a2e, 0x03707344, 0xa4093822, 0x299f31d0,
+	0x082efa98, 0xec4e6c89, 0x452821e6, 0x38d01377, 0xbe5466cf, 0x34e90c6c,
+	0xc0ac29b7, 0xc97c50dd, 0x3f84d5b5, 0xb5470917, 0x9216d5d9, 0x8979fb1b,
+}