Adding upstream version 9.0.3.

Signed-off-by: Daniel Baumann <daniel@debian.org>

17 files changed, 3177 insertions, 0 deletions

diff --git a/models/auth/TestOrphanedOAuth2Applications/oauth2_application.yaml b/models/auth/TestOrphanedOAuth2Applications/oauth2_application.yaml
new file mode 100644
index 0000000..cccb404
--- /dev/null
+++ b/models/auth/TestOrphanedOAuth2Applications/oauth2_application.yaml
@@ -0,0 +1,33 @@
+-
+  id: 1000
+  uid: 0
+  name: "Git Credential Manager"
+  client_id: "e90ee53c-94e2-48ac-9358-a874fb9e0662"
+  redirect_uris: '["http://127.0.0.1", "https://127.0.0.1"]'
+  created_unix: 1712358091
+  updated_unix: 1712358091
+-
+  id: 1001
+  uid: 0
+  name: "git-credential-oauth"
+  client_id: "a4792ccc-144e-407e-86c9-5e7d8d9c3269"
+  redirect_uris: '["http://127.0.0.1", "https://127.0.0.1"]'
+  created_unix: 1712358091
+  updated_unix: 1712358091
+
+-
+  id: 1002
+  uid: 1234567890
+  name: "Should be removed"
+  client_id: "deadc0de-badd-dd11-fee1-deaddecafbad"
+  redirect_uris: '["http://127.0.0.1", "https://127.0.0.1"]'
+  created_unix: 1712358091
+  updated_unix: 1712358091
+-
+  id: 1003
+  uid: 0
+  name: "Global Auth source that should be kept"
+  client_id: "2f3467c1-7b3b-463d-ab04-2ae2b2712826"
+  redirect_uris: '["http://example.com/globalapp", "https://example.com/globalapp"]'
+  created_unix: 1732387292
+  updated_unix: 1732387292
diff --git a/models/auth/access_token.go b/models/auth/access_token.go
new file mode 100644
index 0000000..63331b4
--- /dev/null
+++ b/models/auth/access_token.go
@@ -0,0 +1,236 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"context"
+	"crypto/subtle"
+	"encoding/hex"
+	"fmt"
+	"time"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/util"
+
+	lru "github.com/hashicorp/golang-lru/v2"
+	"xorm.io/builder"
+)
+
+// ErrAccessTokenNotExist represents a "AccessTokenNotExist" kind of error.
+type ErrAccessTokenNotExist struct {
+	Token string
+}
+
+// IsErrAccessTokenNotExist checks if an error is a ErrAccessTokenNotExist.
+func IsErrAccessTokenNotExist(err error) bool {
+	_, ok := err.(ErrAccessTokenNotExist)
+	return ok
+}
+
+func (err ErrAccessTokenNotExist) Error() string {
+	return fmt.Sprintf("access token does not exist [sha: %s]", err.Token)
+}
+
+func (err ErrAccessTokenNotExist) Unwrap() error {
+	return util.ErrNotExist
+}
+
+// ErrAccessTokenEmpty represents a "AccessTokenEmpty" kind of error.
+type ErrAccessTokenEmpty struct{}
+
+// IsErrAccessTokenEmpty checks if an error is a ErrAccessTokenEmpty.
+func IsErrAccessTokenEmpty(err error) bool {
+	_, ok := err.(ErrAccessTokenEmpty)
+	return ok
+}
+
+func (err ErrAccessTokenEmpty) Error() string {
+	return "access token is empty"
+}
+
+func (err ErrAccessTokenEmpty) Unwrap() error {
+	return util.ErrInvalidArgument
+}
+
+var successfulAccessTokenCache *lru.Cache[string, any]
+
+// AccessToken represents a personal access token.
+type AccessToken struct {
+	ID             int64 `xorm:"pk autoincr"`
+	UID            int64 `xorm:"INDEX"`
+	Name           string
+	Token          string `xorm:"-"`
+	TokenHash      string `xorm:"UNIQUE"` // sha256 of token
+	TokenSalt      string
+	TokenLastEight string `xorm:"INDEX token_last_eight"`
+	Scope          AccessTokenScope
+
+	CreatedUnix       timeutil.TimeStamp `xorm:"INDEX created"`
+	UpdatedUnix       timeutil.TimeStamp `xorm:"INDEX updated"`
+	HasRecentActivity bool               `xorm:"-"`
+	HasUsed           bool               `xorm:"-"`
+}
+
+// AfterLoad is invoked from XORM after setting the values of all fields of this object.
+func (t *AccessToken) AfterLoad() {
+	t.HasUsed = t.UpdatedUnix > t.CreatedUnix
+	t.HasRecentActivity = t.UpdatedUnix.AddDuration(7*24*time.Hour) > timeutil.TimeStampNow()
+}
+
+func init() {
+	db.RegisterModel(new(AccessToken), func() error {
+		if setting.SuccessfulTokensCacheSize > 0 {
+			var err error
+			successfulAccessTokenCache, err = lru.New[string, any](setting.SuccessfulTokensCacheSize)
+			if err != nil {
+				return fmt.Errorf("unable to allocate AccessToken cache: %w", err)
+			}
+		} else {
+			successfulAccessTokenCache = nil
+		}
+		return nil
+	})
+}
+
+// NewAccessToken creates new access token.
+func NewAccessToken(ctx context.Context, t *AccessToken) error {
+	salt, err := util.CryptoRandomString(10)
+	if err != nil {
+		return err
+	}
+	token, err := util.CryptoRandomBytes(20)
+	if err != nil {
+		return err
+	}
+	t.TokenSalt = salt
+	t.Token = hex.EncodeToString(token)
+	t.TokenHash = HashToken(t.Token, t.TokenSalt)
+	t.TokenLastEight = t.Token[len(t.Token)-8:]
+	_, err = db.GetEngine(ctx).Insert(t)
+	return err
+}
+
+// DisplayPublicOnly whether to display this as a public-only token.
+func (t *AccessToken) DisplayPublicOnly() bool {
+	publicOnly, err := t.Scope.PublicOnly()
+	if err != nil {
+		return false
+	}
+	return publicOnly
+}
+
+func getAccessTokenIDFromCache(token string) int64 {
+	if successfulAccessTokenCache == nil {
+		return 0
+	}
+	tInterface, ok := successfulAccessTokenCache.Get(token)
+	if !ok {
+		return 0
+	}
+	t, ok := tInterface.(int64)
+	if !ok {
+		return 0
+	}
+	return t
+}
+
+// GetAccessTokenBySHA returns access token by given token value
+func GetAccessTokenBySHA(ctx context.Context, token string) (*AccessToken, error) {
+	if token == "" {
+		return nil, ErrAccessTokenEmpty{}
+	}
+	// A token is defined as being SHA1 sum these are 40 hexadecimal bytes long
+	if len(token) != 40 {
+		return nil, ErrAccessTokenNotExist{token}
+	}
+	for _, x := range []byte(token) {
+		if x < '0' || (x > '9' && x < 'a') || x > 'f' {
+			return nil, ErrAccessTokenNotExist{token}
+		}
+	}
+
+	lastEight := token[len(token)-8:]
+
+	if id := getAccessTokenIDFromCache(token); id > 0 {
+		accessToken := &AccessToken{
+			TokenLastEight: lastEight,
+		}
+		// Re-get the token from the db in case it has been deleted in the intervening period
+		has, err := db.GetEngine(ctx).ID(id).Get(accessToken)
+		if err != nil {
+			return nil, err
+		}
+		if has {
+			return accessToken, nil
+		}
+		successfulAccessTokenCache.Remove(token)
+	}
+
+	var tokens []AccessToken
+	err := db.GetEngine(ctx).Table(&AccessToken{}).Where("token_last_eight = ?", lastEight).Find(&tokens)
+	if err != nil {
+		return nil, err
+	} else if len(tokens) == 0 {
+		return nil, ErrAccessTokenNotExist{token}
+	}
+
+	for _, t := range tokens {
+		tempHash := HashToken(token, t.TokenSalt)
+		if subtle.ConstantTimeCompare([]byte(t.TokenHash), []byte(tempHash)) == 1 {
+			if successfulAccessTokenCache != nil {
+				successfulAccessTokenCache.Add(token, t.ID)
+			}
+			return &t, nil
+		}
+	}
+	return nil, ErrAccessTokenNotExist{token}
+}
+
+// AccessTokenByNameExists checks if a token name has been used already by a user.
+func AccessTokenByNameExists(ctx context.Context, token *AccessToken) (bool, error) {
+	return db.GetEngine(ctx).Table("access_token").Where("name = ?", token.Name).And("uid = ?", token.UID).Exist()
+}
+
+// ListAccessTokensOptions contain filter options
+type ListAccessTokensOptions struct {
+	db.ListOptions
+	Name   string
+	UserID int64
+}
+
+func (opts ListAccessTokensOptions) ToConds() builder.Cond {
+	cond := builder.NewCond()
+	// user id is required, otherwise it will return all result which maybe a possible bug
+	cond = cond.And(builder.Eq{"uid": opts.UserID})
+	if len(opts.Name) > 0 {
+		cond = cond.And(builder.Eq{"name": opts.Name})
+	}
+	return cond
+}
+
+func (opts ListAccessTokensOptions) ToOrders() string {
+	return "created_unix DESC"
+}
+
+// UpdateAccessToken updates information of access token.
+func UpdateAccessToken(ctx context.Context, t *AccessToken) error {
+	_, err := db.GetEngine(ctx).ID(t.ID).AllCols().Update(t)
+	return err
+}
+
+// DeleteAccessTokenByID deletes access token by given ID.
+func DeleteAccessTokenByID(ctx context.Context, id, userID int64) error {
+	cnt, err := db.GetEngine(ctx).ID(id).Delete(&AccessToken{
+		UID: userID,
+	})
+	if err != nil {
+		return err
+	} else if cnt != 1 {
+		return ErrAccessTokenNotExist{}
+	}
+	return nil
+}
diff --git a/models/auth/access_token_scope.go b/models/auth/access_token_scope.go
new file mode 100644
index 0000000..003ca5c
--- /dev/null
+++ b/models/auth/access_token_scope.go
@@ -0,0 +1,350 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/models/perm"
+)
+
+// AccessTokenScopeCategory represents the scope category for an access token
+type AccessTokenScopeCategory int
+
+const (
+	AccessTokenScopeCategoryActivityPub = iota
+	AccessTokenScopeCategoryAdmin
+	AccessTokenScopeCategoryMisc // WARN: this is now just a placeholder, don't remove it which will change the following values
+	AccessTokenScopeCategoryNotification
+	AccessTokenScopeCategoryOrganization
+	AccessTokenScopeCategoryPackage
+	AccessTokenScopeCategoryIssue
+	AccessTokenScopeCategoryRepository
+	AccessTokenScopeCategoryUser
+)
+
+// AllAccessTokenScopeCategories contains all access token scope categories
+var AllAccessTokenScopeCategories = []AccessTokenScopeCategory{
+	AccessTokenScopeCategoryActivityPub,
+	AccessTokenScopeCategoryAdmin,
+	AccessTokenScopeCategoryMisc,
+	AccessTokenScopeCategoryNotification,
+	AccessTokenScopeCategoryOrganization,
+	AccessTokenScopeCategoryPackage,
+	AccessTokenScopeCategoryIssue,
+	AccessTokenScopeCategoryRepository,
+	AccessTokenScopeCategoryUser,
+}
+
+// AccessTokenScopeLevel represents the access levels without a given scope category
+type AccessTokenScopeLevel int
+
+const (
+	NoAccess AccessTokenScopeLevel = iota
+	Read
+	Write
+)
+
+// AccessTokenScope represents the scope for an access token.
+type AccessTokenScope string
+
+// for all categories, write implies read
+const (
+	AccessTokenScopeAll        AccessTokenScope = "all"
+	AccessTokenScopePublicOnly AccessTokenScope = "public-only" // limited to public orgs/repos
+
+	AccessTokenScopeReadActivityPub  AccessTokenScope = "read:activitypub"
+	AccessTokenScopeWriteActivityPub AccessTokenScope = "write:activitypub"
+
+	AccessTokenScopeReadAdmin  AccessTokenScope = "read:admin"
+	AccessTokenScopeWriteAdmin AccessTokenScope = "write:admin"
+
+	AccessTokenScopeReadMisc  AccessTokenScope = "read:misc"
+	AccessTokenScopeWriteMisc AccessTokenScope = "write:misc"
+
+	AccessTokenScopeReadNotification  AccessTokenScope = "read:notification"
+	AccessTokenScopeWriteNotification AccessTokenScope = "write:notification"
+
+	AccessTokenScopeReadOrganization  AccessTokenScope = "read:organization"
+	AccessTokenScopeWriteOrganization AccessTokenScope = "write:organization"
+
+	AccessTokenScopeReadPackage  AccessTokenScope = "read:package"
+	AccessTokenScopeWritePackage AccessTokenScope = "write:package"
+
+	AccessTokenScopeReadIssue  AccessTokenScope = "read:issue"
+	AccessTokenScopeWriteIssue AccessTokenScope = "write:issue"
+
+	AccessTokenScopeReadRepository  AccessTokenScope = "read:repository"
+	AccessTokenScopeWriteRepository AccessTokenScope = "write:repository"
+
+	AccessTokenScopeReadUser  AccessTokenScope = "read:user"
+	AccessTokenScopeWriteUser AccessTokenScope = "write:user"
+)
+
+// accessTokenScopeBitmap represents a bitmap of access token scopes.
+type accessTokenScopeBitmap uint64
+
+// Bitmap of each scope, including the child scopes.
+const (
+	// AccessTokenScopeAllBits is the bitmap of all access token scopes
+	accessTokenScopeAllBits accessTokenScopeBitmap = accessTokenScopeWriteActivityPubBits |
+		accessTokenScopeWriteAdminBits | accessTokenScopeWriteMiscBits | accessTokenScopeWriteNotificationBits |
+		accessTokenScopeWriteOrganizationBits | accessTokenScopeWritePackageBits | accessTokenScopeWriteIssueBits |
+		accessTokenScopeWriteRepositoryBits | accessTokenScopeWriteUserBits
+
+	accessTokenScopePublicOnlyBits accessTokenScopeBitmap = 1 << iota
+
+	accessTokenScopeReadActivityPubBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWriteActivityPubBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadActivityPubBits
+
+	accessTokenScopeReadAdminBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWriteAdminBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadAdminBits
+
+	accessTokenScopeReadMiscBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWriteMiscBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadMiscBits
+
+	accessTokenScopeReadNotificationBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWriteNotificationBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadNotificationBits
+
+	accessTokenScopeReadOrganizationBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWriteOrganizationBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadOrganizationBits
+
+	accessTokenScopeReadPackageBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWritePackageBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadPackageBits
+
+	accessTokenScopeReadIssueBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWriteIssueBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadIssueBits
+
+	accessTokenScopeReadRepositoryBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWriteRepositoryBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadRepositoryBits
+
+	accessTokenScopeReadUserBits  accessTokenScopeBitmap = 1 << iota
+	accessTokenScopeWriteUserBits accessTokenScopeBitmap = 1<<iota | accessTokenScopeReadUserBits
+
+	// The current implementation only supports up to 64 token scopes.
+	// If we need to support > 64 scopes,
+	// refactoring the whole implementation in this file (and only this file) is needed.
+)
+
+// allAccessTokenScopes contains all access token scopes.
+// The order is important: parent scope must precede child scopes.
+var allAccessTokenScopes = []AccessTokenScope{
+	AccessTokenScopePublicOnly,
+	AccessTokenScopeWriteActivityPub, AccessTokenScopeReadActivityPub,
+	AccessTokenScopeWriteAdmin, AccessTokenScopeReadAdmin,
+	AccessTokenScopeWriteMisc, AccessTokenScopeReadMisc,
+	AccessTokenScopeWriteNotification, AccessTokenScopeReadNotification,
+	AccessTokenScopeWriteOrganization, AccessTokenScopeReadOrganization,
+	AccessTokenScopeWritePackage, AccessTokenScopeReadPackage,
+	AccessTokenScopeWriteIssue, AccessTokenScopeReadIssue,
+	AccessTokenScopeWriteRepository, AccessTokenScopeReadRepository,
+	AccessTokenScopeWriteUser, AccessTokenScopeReadUser,
+}
+
+// allAccessTokenScopeBits contains all access token scopes.
+var allAccessTokenScopeBits = map[AccessTokenScope]accessTokenScopeBitmap{
+	AccessTokenScopeAll:               accessTokenScopeAllBits,
+	AccessTokenScopePublicOnly:        accessTokenScopePublicOnlyBits,
+	AccessTokenScopeReadActivityPub:   accessTokenScopeReadActivityPubBits,
+	AccessTokenScopeWriteActivityPub:  accessTokenScopeWriteActivityPubBits,
+	AccessTokenScopeReadAdmin:         accessTokenScopeReadAdminBits,
+	AccessTokenScopeWriteAdmin:        accessTokenScopeWriteAdminBits,
+	AccessTokenScopeReadMisc:          accessTokenScopeReadMiscBits,
+	AccessTokenScopeWriteMisc:         accessTokenScopeWriteMiscBits,
+	AccessTokenScopeReadNotification:  accessTokenScopeReadNotificationBits,
+	AccessTokenScopeWriteNotification: accessTokenScopeWriteNotificationBits,
+	AccessTokenScopeReadOrganization:  accessTokenScopeReadOrganizationBits,
+	AccessTokenScopeWriteOrganization: accessTokenScopeWriteOrganizationBits,
+	AccessTokenScopeReadPackage:       accessTokenScopeReadPackageBits,
+	AccessTokenScopeWritePackage:      accessTokenScopeWritePackageBits,
+	AccessTokenScopeReadIssue:         accessTokenScopeReadIssueBits,
+	AccessTokenScopeWriteIssue:        accessTokenScopeWriteIssueBits,
+	AccessTokenScopeReadRepository:    accessTokenScopeReadRepositoryBits,
+	AccessTokenScopeWriteRepository:   accessTokenScopeWriteRepositoryBits,
+	AccessTokenScopeReadUser:          accessTokenScopeReadUserBits,
+	AccessTokenScopeWriteUser:         accessTokenScopeWriteUserBits,
+}
+
+// readAccessTokenScopes maps a scope category to the read permission scope
+var accessTokenScopes = map[AccessTokenScopeLevel]map[AccessTokenScopeCategory]AccessTokenScope{
+	Read: {
+		AccessTokenScopeCategoryActivityPub:  AccessTokenScopeReadActivityPub,
+		AccessTokenScopeCategoryAdmin:        AccessTokenScopeReadAdmin,
+		AccessTokenScopeCategoryMisc:         AccessTokenScopeReadMisc,
+		AccessTokenScopeCategoryNotification: AccessTokenScopeReadNotification,
+		AccessTokenScopeCategoryOrganization: AccessTokenScopeReadOrganization,
+		AccessTokenScopeCategoryPackage:      AccessTokenScopeReadPackage,
+		AccessTokenScopeCategoryIssue:        AccessTokenScopeReadIssue,
+		AccessTokenScopeCategoryRepository:   AccessTokenScopeReadRepository,
+		AccessTokenScopeCategoryUser:         AccessTokenScopeReadUser,
+	},
+	Write: {
+		AccessTokenScopeCategoryActivityPub:  AccessTokenScopeWriteActivityPub,
+		AccessTokenScopeCategoryAdmin:        AccessTokenScopeWriteAdmin,
+		AccessTokenScopeCategoryMisc:         AccessTokenScopeWriteMisc,
+		AccessTokenScopeCategoryNotification: AccessTokenScopeWriteNotification,
+		AccessTokenScopeCategoryOrganization: AccessTokenScopeWriteOrganization,
+		AccessTokenScopeCategoryPackage:      AccessTokenScopeWritePackage,
+		AccessTokenScopeCategoryIssue:        AccessTokenScopeWriteIssue,
+		AccessTokenScopeCategoryRepository:   AccessTokenScopeWriteRepository,
+		AccessTokenScopeCategoryUser:         AccessTokenScopeWriteUser,
+	},
+}
+
+// GetRequiredScopes gets the specific scopes for a given level and categories
+func GetRequiredScopes(level AccessTokenScopeLevel, scopeCategories ...AccessTokenScopeCategory) []AccessTokenScope {
+	scopes := make([]AccessTokenScope, 0, len(scopeCategories))
+	for _, cat := range scopeCategories {
+		scopes = append(scopes, accessTokenScopes[level][cat])
+	}
+	return scopes
+}
+
+// ContainsCategory checks if a list of categories contains a specific category
+func ContainsCategory(categories []AccessTokenScopeCategory, category AccessTokenScopeCategory) bool {
+	for _, c := range categories {
+		if c == category {
+			return true
+		}
+	}
+	return false
+}
+
+// GetScopeLevelFromAccessMode converts permission access mode to scope level
+func GetScopeLevelFromAccessMode(mode perm.AccessMode) AccessTokenScopeLevel {
+	switch mode {
+	case perm.AccessModeNone:
+		return NoAccess
+	case perm.AccessModeRead:
+		return Read
+	case perm.AccessModeWrite:
+		return Write
+	case perm.AccessModeAdmin:
+		return Write
+	case perm.AccessModeOwner:
+		return Write
+	default:
+		return NoAccess
+	}
+}
+
+// parse the scope string into a bitmap, thus removing possible duplicates.
+func (s AccessTokenScope) parse() (accessTokenScopeBitmap, error) {
+	var bitmap accessTokenScopeBitmap
+
+	// The following is the more performant equivalent of 'for _, v := range strings.Split(remainingScope, ",")' as this is hot code
+	remainingScopes := string(s)
+	for len(remainingScopes) > 0 {
+		i := strings.IndexByte(remainingScopes, ',')
+		var v string
+		if i < 0 {
+			v = remainingScopes
+			remainingScopes = ""
+		} else if i+1 >= len(remainingScopes) {
+			v = remainingScopes[:i]
+			remainingScopes = ""
+		} else {
+			v = remainingScopes[:i]
+			remainingScopes = remainingScopes[i+1:]
+		}
+		singleScope := AccessTokenScope(v)
+		if singleScope == "" || singleScope == "sudo" {
+			continue
+		}
+		if singleScope == AccessTokenScopeAll {
+			bitmap |= accessTokenScopeAllBits
+			continue
+		}
+
+		bits, ok := allAccessTokenScopeBits[singleScope]
+		if !ok {
+			return 0, fmt.Errorf("invalid access token scope: %s", singleScope)
+		}
+		bitmap |= bits
+	}
+
+	return bitmap, nil
+}
+
+// StringSlice returns the AccessTokenScope as a []string
+func (s AccessTokenScope) StringSlice() []string {
+	return strings.Split(string(s), ",")
+}
+
+// Normalize returns a normalized scope string without any duplicates.
+func (s AccessTokenScope) Normalize() (AccessTokenScope, error) {
+	bitmap, err := s.parse()
+	if err != nil {
+		return "", err
+	}
+
+	return bitmap.toScope(), nil
+}
+
+// PublicOnly checks if this token scope is limited to public resources
+func (s AccessTokenScope) PublicOnly() (bool, error) {
+	bitmap, err := s.parse()
+	if err != nil {
+		return false, err
+	}
+
+	return bitmap.hasScope(AccessTokenScopePublicOnly)
+}
+
+// HasScope returns true if the string has the given scope
+func (s AccessTokenScope) HasScope(scopes ...AccessTokenScope) (bool, error) {
+	bitmap, err := s.parse()
+	if err != nil {
+		return false, err
+	}
+
+	for _, s := range scopes {
+		if has, err := bitmap.hasScope(s); !has || err != nil {
+			return has, err
+		}
+	}
+
+	return true, nil
+}
+
+// hasScope returns true if the string has the given scope
+func (bitmap accessTokenScopeBitmap) hasScope(scope AccessTokenScope) (bool, error) {
+	expectedBits, ok := allAccessTokenScopeBits[scope]
+	if !ok {
+		return false, fmt.Errorf("invalid access token scope: %s", scope)
+	}
+
+	return bitmap&expectedBits == expectedBits, nil
+}
+
+// toScope returns a normalized scope string without any duplicates.
+func (bitmap accessTokenScopeBitmap) toScope() AccessTokenScope {
+	var scopes []string
+
+	// iterate over all scopes, and reconstruct the bitmap
+	// if the reconstructed bitmap doesn't change, then the scope is already included
+	var reconstruct accessTokenScopeBitmap
+
+	for _, singleScope := range allAccessTokenScopes {
+		// no need for error checking here, since we know the scope is valid
+		if ok, _ := bitmap.hasScope(singleScope); ok {
+			current := reconstruct | allAccessTokenScopeBits[singleScope]
+			if current == reconstruct {
+				continue
+			}
+
+			reconstruct = current
+			scopes = append(scopes, string(singleScope))
+		}
+	}
+
+	scope := AccessTokenScope(strings.Join(scopes, ","))
+	scope = AccessTokenScope(strings.ReplaceAll(
+		string(scope),
+		"write:activitypub,write:admin,write:misc,write:notification,write:organization,write:package,write:issue,write:repository,write:user",
+		"all",
+	))
+	return scope
+}
diff --git a/models/auth/access_token_scope_test.go b/models/auth/access_token_scope_test.go
new file mode 100644
index 0000000..d11c5e6
--- /dev/null
+++ b/models/auth/access_token_scope_test.go
@@ -0,0 +1,90 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type scopeTestNormalize struct {
+	in  AccessTokenScope
+	out AccessTokenScope
+	err error
+}
+
+func TestAccessTokenScope_Normalize(t *testing.T) {
+	tests := []scopeTestNormalize{
+		{"", "", nil},
+		{"write:misc,write:notification,read:package,write:notification,public-only", "public-only,write:misc,write:notification,read:package", nil},
+		{"all,sudo", "all", nil},
+		{"write:activitypub,write:admin,write:misc,write:notification,write:organization,write:package,write:issue,write:repository,write:user", "all", nil},
+		{"write:activitypub,write:admin,write:misc,write:notification,write:organization,write:package,write:issue,write:repository,write:user,public-only", "public-only,all", nil},
+	}
+
+	for _, scope := range []string{"activitypub", "admin", "misc", "notification", "organization", "package", "issue", "repository", "user"} {
+		tests = append(tests,
+			scopeTestNormalize{AccessTokenScope(fmt.Sprintf("read:%s", scope)), AccessTokenScope(fmt.Sprintf("read:%s", scope)), nil},
+			scopeTestNormalize{AccessTokenScope(fmt.Sprintf("write:%s", scope)), AccessTokenScope(fmt.Sprintf("write:%s", scope)), nil},
+			scopeTestNormalize{AccessTokenScope(fmt.Sprintf("write:%[1]s,read:%[1]s", scope)), AccessTokenScope(fmt.Sprintf("write:%s", scope)), nil},
+			scopeTestNormalize{AccessTokenScope(fmt.Sprintf("read:%[1]s,write:%[1]s", scope)), AccessTokenScope(fmt.Sprintf("write:%s", scope)), nil},
+			scopeTestNormalize{AccessTokenScope(fmt.Sprintf("read:%[1]s,write:%[1]s,write:%[1]s", scope)), AccessTokenScope(fmt.Sprintf("write:%s", scope)), nil},
+		)
+	}
+
+	for _, test := range tests {
+		t.Run(string(test.in), func(t *testing.T) {
+			scope, err := test.in.Normalize()
+			assert.Equal(t, test.out, scope)
+			assert.Equal(t, test.err, err)
+		})
+	}
+}
+
+type scopeTestHasScope struct {
+	in    AccessTokenScope
+	scope AccessTokenScope
+	out   bool
+	err   error
+}
+
+func TestAccessTokenScope_HasScope(t *testing.T) {
+	tests := []scopeTestHasScope{
+		{"read:admin", "write:package", false, nil},
+		{"all", "write:package", true, nil},
+		{"write:package", "all", false, nil},
+		{"public-only", "read:issue", false, nil},
+	}
+
+	for _, scope := range []string{"activitypub", "admin", "misc", "notification", "organization", "package", "issue", "repository", "user"} {
+		tests = append(tests,
+			scopeTestHasScope{
+				AccessTokenScope(fmt.Sprintf("read:%s", scope)),
+				AccessTokenScope(fmt.Sprintf("read:%s", scope)), true, nil,
+			},
+			scopeTestHasScope{
+				AccessTokenScope(fmt.Sprintf("write:%s", scope)),
+				AccessTokenScope(fmt.Sprintf("write:%s", scope)), true, nil,
+			},
+			scopeTestHasScope{
+				AccessTokenScope(fmt.Sprintf("write:%s", scope)),
+				AccessTokenScope(fmt.Sprintf("read:%s", scope)), true, nil,
+			},
+			scopeTestHasScope{
+				AccessTokenScope(fmt.Sprintf("read:%s", scope)),
+				AccessTokenScope(fmt.Sprintf("write:%s", scope)), false, nil,
+			},
+		)
+	}
+
+	for _, test := range tests {
+		t.Run(string(test.in), func(t *testing.T) {
+			hasScope, err := test.in.HasScope(test.scope)
+			assert.Equal(t, test.out, hasScope)
+			assert.Equal(t, test.err, err)
+		})
+	}
+}
diff --git a/models/auth/access_token_test.go b/models/auth/access_token_test.go
new file mode 100644
index 0000000..e6ea487
--- /dev/null
+++ b/models/auth/access_token_test.go
@@ -0,0 +1,133 @@
+// Copyright 2016 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth_test
+
+import (
+	"testing"
+
+	auth_model "code.gitea.io/gitea/models/auth"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewAccessToken(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	token := &auth_model.AccessToken{
+		UID:  3,
+		Name: "Token C",
+	}
+	require.NoError(t, auth_model.NewAccessToken(db.DefaultContext, token))
+	unittest.AssertExistsAndLoadBean(t, token)
+
+	invalidToken := &auth_model.AccessToken{
+		ID:   token.ID, // duplicate
+		UID:  2,
+		Name: "Token F",
+	}
+	require.Error(t, auth_model.NewAccessToken(db.DefaultContext, invalidToken))
+}
+
+func TestAccessTokenByNameExists(t *testing.T) {
+	name := "Token Gitea"
+
+	require.NoError(t, unittest.PrepareTestDatabase())
+	token := &auth_model.AccessToken{
+		UID:  3,
+		Name: name,
+	}
+
+	// Check to make sure it doesn't exists already
+	exist, err := auth_model.AccessTokenByNameExists(db.DefaultContext, token)
+	require.NoError(t, err)
+	assert.False(t, exist)
+
+	// Save it to the database
+	require.NoError(t, auth_model.NewAccessToken(db.DefaultContext, token))
+	unittest.AssertExistsAndLoadBean(t, token)
+
+	// This token must be found by name in the DB now
+	exist, err = auth_model.AccessTokenByNameExists(db.DefaultContext, token)
+	require.NoError(t, err)
+	assert.True(t, exist)
+
+	user4Token := &auth_model.AccessToken{
+		UID:  4,
+		Name: name,
+	}
+
+	// Name matches but different user ID, this shouldn't exists in the
+	// database
+	exist, err = auth_model.AccessTokenByNameExists(db.DefaultContext, user4Token)
+	require.NoError(t, err)
+	assert.False(t, exist)
+}
+
+func TestGetAccessTokenBySHA(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	token, err := auth_model.GetAccessTokenBySHA(db.DefaultContext, "d2c6c1ba3890b309189a8e618c72a162e4efbf36")
+	require.NoError(t, err)
+	assert.Equal(t, int64(1), token.UID)
+	assert.Equal(t, "Token A", token.Name)
+	assert.Equal(t, "2b3668e11cb82d3af8c6e4524fc7841297668f5008d1626f0ad3417e9fa39af84c268248b78c481daa7e5dc437784003494f", token.TokenHash)
+	assert.Equal(t, "e4efbf36", token.TokenLastEight)
+
+	_, err = auth_model.GetAccessTokenBySHA(db.DefaultContext, "notahash")
+	require.Error(t, err)
+	assert.True(t, auth_model.IsErrAccessTokenNotExist(err))
+
+	_, err = auth_model.GetAccessTokenBySHA(db.DefaultContext, "")
+	require.Error(t, err)
+	assert.True(t, auth_model.IsErrAccessTokenEmpty(err))
+}
+
+func TestListAccessTokens(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	tokens, err := db.Find[auth_model.AccessToken](db.DefaultContext, auth_model.ListAccessTokensOptions{UserID: 1})
+	require.NoError(t, err)
+	if assert.Len(t, tokens, 2) {
+		assert.Equal(t, int64(1), tokens[0].UID)
+		assert.Equal(t, int64(1), tokens[1].UID)
+		assert.Contains(t, []string{tokens[0].Name, tokens[1].Name}, "Token A")
+		assert.Contains(t, []string{tokens[0].Name, tokens[1].Name}, "Token B")
+	}
+
+	tokens, err = db.Find[auth_model.AccessToken](db.DefaultContext, auth_model.ListAccessTokensOptions{UserID: 2})
+	require.NoError(t, err)
+	if assert.Len(t, tokens, 1) {
+		assert.Equal(t, int64(2), tokens[0].UID)
+		assert.Equal(t, "Token A", tokens[0].Name)
+	}
+
+	tokens, err = db.Find[auth_model.AccessToken](db.DefaultContext, auth_model.ListAccessTokensOptions{UserID: 100})
+	require.NoError(t, err)
+	assert.Empty(t, tokens)
+}
+
+func TestUpdateAccessToken(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	token, err := auth_model.GetAccessTokenBySHA(db.DefaultContext, "4c6f36e6cf498e2a448662f915d932c09c5a146c")
+	require.NoError(t, err)
+	token.Name = "Token Z"
+
+	require.NoError(t, auth_model.UpdateAccessToken(db.DefaultContext, token))
+	unittest.AssertExistsAndLoadBean(t, token)
+}
+
+func TestDeleteAccessTokenByID(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+
+	token, err := auth_model.GetAccessTokenBySHA(db.DefaultContext, "4c6f36e6cf498e2a448662f915d932c09c5a146c")
+	require.NoError(t, err)
+	assert.Equal(t, int64(1), token.UID)
+
+	require.NoError(t, auth_model.DeleteAccessTokenByID(db.DefaultContext, token.ID, 1))
+	unittest.AssertNotExistsBean(t, token)
+
+	err = auth_model.DeleteAccessTokenByID(db.DefaultContext, 100, 100)
+	require.Error(t, err)
+	assert.True(t, auth_model.IsErrAccessTokenNotExist(err))
+}
diff --git a/models/auth/auth_token.go b/models/auth/auth_token.go
new file mode 100644
index 0000000..c64af3e
--- /dev/null
+++ b/models/auth/auth_token.go
@@ -0,0 +1,116 @@
+// Copyright 2023 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"time"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/util"
+)
+
+type AuthorizationPurpose string
+
+var (
+	// Used to store long term authorization tokens.
+	LongTermAuthorization AuthorizationPurpose = "long_term_authorization"
+
+	// Used to activate a user account.
+	UserActivation AuthorizationPurpose = "user_activation"
+
+	// Used to reset the password.
+	PasswordReset AuthorizationPurpose = "password_reset"
+)
+
+// Used to activate the specified email address for a user.
+func EmailActivation(email string) AuthorizationPurpose {
+	return AuthorizationPurpose("email_activation:" + email)
+}
+
+// AuthorizationToken represents a authorization token to a user.
+type AuthorizationToken struct {
+	ID              int64  `xorm:"pk autoincr"`
+	UID             int64  `xorm:"INDEX"`
+	LookupKey       string `xorm:"INDEX UNIQUE"`
+	HashedValidator string
+	Purpose         AuthorizationPurpose `xorm:"NOT NULL DEFAULT 'long_term_authorization'"`
+	Expiry          timeutil.TimeStamp
+}
+
+// TableName provides the real table name.
+func (AuthorizationToken) TableName() string {
+	return "forgejo_auth_token"
+}
+
+func init() {
+	db.RegisterModel(new(AuthorizationToken))
+}
+
+// IsExpired returns if the authorization token is expired.
+func (authToken *AuthorizationToken) IsExpired() bool {
+	return authToken.Expiry.AsLocalTime().Before(time.Now())
+}
+
+// GenerateAuthToken generates a new authentication token for the given user.
+// It returns the lookup key and validator values that should be passed to the
+// user via a long-term cookie.
+func GenerateAuthToken(ctx context.Context, userID int64, expiry timeutil.TimeStamp, purpose AuthorizationPurpose) (lookupKey, validator string, err error) {
+	// Request 64 random bytes. The first 32 bytes will be used for the lookupKey
+	// and the other 32 bytes will be used for the validator.
+	rBytes, err := util.CryptoRandomBytes(64)
+	if err != nil {
+		return "", "", err
+	}
+	hexEncoded := hex.EncodeToString(rBytes)
+	validator, lookupKey = hexEncoded[64:], hexEncoded[:64]
+
+	_, err = db.GetEngine(ctx).Insert(&AuthorizationToken{
+		UID:             userID,
+		Expiry:          expiry,
+		LookupKey:       lookupKey,
+		HashedValidator: HashValidator(rBytes[32:]),
+		Purpose:         purpose,
+	})
+	return lookupKey, validator, err
+}
+
+// FindAuthToken will find a authorization token via the lookup key.
+func FindAuthToken(ctx context.Context, lookupKey string, purpose AuthorizationPurpose) (*AuthorizationToken, error) {
+	var authToken AuthorizationToken
+	has, err := db.GetEngine(ctx).Where("lookup_key = ? AND purpose = ?", lookupKey, purpose).Get(&authToken)
+	if err != nil {
+		return nil, err
+	} else if !has {
+		return nil, fmt.Errorf("lookup key %q: %w", lookupKey, util.ErrNotExist)
+	}
+	return &authToken, nil
+}
+
+// DeleteAuthToken will delete the authorization token.
+func DeleteAuthToken(ctx context.Context, authToken *AuthorizationToken) error {
+	_, err := db.DeleteByBean(ctx, authToken)
+	return err
+}
+
+// DeleteAuthTokenByUser will delete all authorization tokens for the user.
+func DeleteAuthTokenByUser(ctx context.Context, userID int64) error {
+	if userID == 0 {
+		return nil
+	}
+
+	_, err := db.DeleteByBean(ctx, &AuthorizationToken{UID: userID})
+	return err
+}
+
+// HashValidator will return a hexified hashed version of the validator.
+func HashValidator(validator []byte) string {
+	h := sha256.New()
+	h.Write(validator)
+	return hex.EncodeToString(h.Sum(nil))
+}
diff --git a/models/auth/main_test.go b/models/auth/main_test.go
new file mode 100644
index 0000000..d772ea6
--- /dev/null
+++ b/models/auth/main_test.go
@@ -0,0 +1,20 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth_test
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/unittest"
+
+	_ "code.gitea.io/gitea/models"
+	_ "code.gitea.io/gitea/models/actions"
+	_ "code.gitea.io/gitea/models/activities"
+	_ "code.gitea.io/gitea/models/auth"
+	_ "code.gitea.io/gitea/models/perm/access"
+)
+
+func TestMain(m *testing.M) {
+	unittest.MainTest(m)
+}
diff --git a/models/auth/oauth2.go b/models/auth/oauth2.go
new file mode 100644
index 0000000..9a78544
--- /dev/null
+++ b/models/auth/oauth2.go
@@ -0,0 +1,678 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/base32"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"net"
+	"net/url"
+	"strings"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/container"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/util"
+
+	uuid "github.com/google/uuid"
+	"golang.org/x/crypto/bcrypt"
+	"xorm.io/builder"
+	"xorm.io/xorm"
+)
+
+// OAuth2Application represents an OAuth2 client (RFC 6749)
+type OAuth2Application struct {
+	ID           int64 `xorm:"pk autoincr"`
+	UID          int64 `xorm:"INDEX"`
+	Name         string
+	ClientID     string `xorm:"unique"`
+	ClientSecret string
+	// OAuth defines both Confidential and Public client types
+	// https://datatracker.ietf.org/doc/html/rfc6749#section-2.1
+	// "Authorization servers MUST record the client type in the client registration details"
+	// https://datatracker.ietf.org/doc/html/rfc8252#section-8.4
+	ConfidentialClient bool               `xorm:"NOT NULL DEFAULT TRUE"`
+	RedirectURIs       []string           `xorm:"redirect_uris JSON TEXT"`
+	CreatedUnix        timeutil.TimeStamp `xorm:"INDEX created"`
+	UpdatedUnix        timeutil.TimeStamp `xorm:"INDEX updated"`
+}
+
+func init() {
+	db.RegisterModel(new(OAuth2Application))
+	db.RegisterModel(new(OAuth2AuthorizationCode))
+	db.RegisterModel(new(OAuth2Grant))
+}
+
+type BuiltinOAuth2Application struct {
+	ConfigName   string
+	DisplayName  string
+	RedirectURIs []string
+}
+
+func BuiltinApplications() map[string]*BuiltinOAuth2Application {
+	m := make(map[string]*BuiltinOAuth2Application)
+	m["a4792ccc-144e-407e-86c9-5e7d8d9c3269"] = &BuiltinOAuth2Application{
+		ConfigName:   "git-credential-oauth",
+		DisplayName:  "git-credential-oauth",
+		RedirectURIs: []string{"http://127.0.0.1", "https://127.0.0.1"},
+	}
+	m["e90ee53c-94e2-48ac-9358-a874fb9e0662"] = &BuiltinOAuth2Application{
+		ConfigName:   "git-credential-manager",
+		DisplayName:  "Git Credential Manager",
+		RedirectURIs: []string{"http://127.0.0.1", "https://127.0.0.1"},
+	}
+	m["d57cb8c4-630c-4168-8324-ec79935e18d4"] = &BuiltinOAuth2Application{
+		ConfigName:   "tea",
+		DisplayName:  "tea",
+		RedirectURIs: []string{"http://127.0.0.1", "https://127.0.0.1"},
+	}
+	return m
+}
+
+func BuiltinApplicationsClientIDs() (clientIDs []string) {
+	for clientID := range BuiltinApplications() {
+		clientIDs = append(clientIDs, clientID)
+	}
+	return clientIDs
+}
+
+func Init(ctx context.Context) error {
+	builtinApps := BuiltinApplications()
+	var builtinAllClientIDs []string
+	for clientID := range builtinApps {
+		builtinAllClientIDs = append(builtinAllClientIDs, clientID)
+	}
+
+	var registeredApps []*OAuth2Application
+	if err := db.GetEngine(ctx).In("client_id", builtinAllClientIDs).Find(&registeredApps); err != nil {
+		return err
+	}
+
+	clientIDsToAdd := container.Set[string]{}
+	for _, configName := range setting.OAuth2.DefaultApplications {
+		found := false
+		for clientID, builtinApp := range builtinApps {
+			if builtinApp.ConfigName == configName {
+				clientIDsToAdd.Add(clientID) // add all user-configured apps to the "add" list
+				found = true
+			}
+		}
+		if !found {
+			return fmt.Errorf("unknown oauth2 application: %q", configName)
+		}
+	}
+	clientIDsToDelete := container.Set[string]{}
+	for _, app := range registeredApps {
+		if !clientIDsToAdd.Contains(app.ClientID) {
+			clientIDsToDelete.Add(app.ClientID) // if a registered app is not in the "add" list, it should be deleted
+		}
+	}
+	for _, app := range registeredApps {
+		clientIDsToAdd.Remove(app.ClientID) // no need to re-add existing (registered) apps, so remove them from the set
+	}
+
+	for _, app := range registeredApps {
+		if clientIDsToDelete.Contains(app.ClientID) {
+			if err := deleteOAuth2Application(ctx, app.ID, 0); err != nil {
+				return err
+			}
+		}
+	}
+	for clientID := range clientIDsToAdd {
+		builtinApp := builtinApps[clientID]
+		if err := db.Insert(ctx, &OAuth2Application{
+			Name:         builtinApp.DisplayName,
+			ClientID:     clientID,
+			RedirectURIs: builtinApp.RedirectURIs,
+		}); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// TableName sets the table name to `oauth2_application`
+func (app *OAuth2Application) TableName() string {
+	return "oauth2_application"
+}
+
+// ContainsRedirectURI checks if redirectURI is allowed for app
+func (app *OAuth2Application) ContainsRedirectURI(redirectURI string) bool {
+	// OAuth2 requires the redirect URI to be an exact match, no dynamic parts are allowed.
+	// https://stackoverflow.com/questions/55524480/should-dynamic-query-parameters-be-present-in-the-redirection-uri-for-an-oauth2
+	// https://www.rfc-editor.org/rfc/rfc6819#section-5.2.3.3
+	// https://openid.net/specs/openid-connect-core-1_0.html#AuthRequest
+	// https://datatracker.ietf.org/doc/html/draft-ietf-oauth-security-topics-12#section-3.1
+	contains := func(s string) bool {
+		s = strings.TrimSuffix(strings.ToLower(s), "/")
+		for _, u := range app.RedirectURIs {
+			if strings.TrimSuffix(strings.ToLower(u), "/") == s {
+				return true
+			}
+		}
+		return false
+	}
+	if !app.ConfidentialClient {
+		uri, err := url.Parse(redirectURI)
+		// ignore port for http loopback uris following https://datatracker.ietf.org/doc/html/rfc8252#section-7.3
+		if err == nil && uri.Scheme == "http" && uri.Port() != "" {
+			ip := net.ParseIP(uri.Hostname())
+			if ip != nil && ip.IsLoopback() {
+				// strip port
+				uri.Host = uri.Hostname()
+				if contains(uri.String()) {
+					return true
+				}
+			}
+		}
+	}
+	return contains(redirectURI)
+}
+
+// Base32 characters, but lowercased.
+const lowerBase32Chars = "abcdefghijklmnopqrstuvwxyz234567"
+
+// base32 encoder that uses lowered characters without padding.
+var base32Lower = base32.NewEncoding(lowerBase32Chars).WithPadding(base32.NoPadding)
+
+// GenerateClientSecret will generate the client secret and returns the plaintext and saves the hash at the database
+func (app *OAuth2Application) GenerateClientSecret(ctx context.Context) (string, error) {
+	rBytes, err := util.CryptoRandomBytes(32)
+	if err != nil {
+		return "", err
+	}
+	// Add a prefix to the base32, this is in order to make it easier
+	// for code scanners to grab sensitive tokens.
+	clientSecret := "gto_" + base32Lower.EncodeToString(rBytes)
+
+	hashedSecret, err := bcrypt.GenerateFromPassword([]byte(clientSecret), bcrypt.DefaultCost)
+	if err != nil {
+		return "", err
+	}
+	app.ClientSecret = string(hashedSecret)
+	if _, err := db.GetEngine(ctx).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(ctx context.Context, userID int64) (grant *OAuth2Grant, err error) {
+	grant = new(OAuth2Grant)
+	if has, err := db.GetEngine(ctx).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(ctx context.Context, userID int64, scope string) (*OAuth2Grant, error) {
+	grant := &OAuth2Grant{
+		ApplicationID: app.ID,
+		UserID:        userID,
+		Scope:         scope,
+	}
+	err := db.Insert(ctx, 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(ctx context.Context, clientID string) (app *OAuth2Application, err error) {
+	app = new(OAuth2Application)
+	has, err := db.GetEngine(ctx).Where("client_id = ?", clientID).Get(app)
+	if !has {
+		return nil, ErrOAuthClientIDInvalid{ClientID: clientID}
+	}
+	return app, err
+}
+
+// GetOAuth2ApplicationByID returns the oauth2 application with the given id. Returns an error if not found.
+func GetOAuth2ApplicationByID(ctx context.Context, id int64) (app *OAuth2Application, err error) {
+	app = new(OAuth2Application)
+	has, err := db.GetEngine(ctx).ID(id).Get(app)
+	if err != nil {
+		return nil, err
+	}
+	if !has {
+		return nil, ErrOAuthApplicationNotFound{ID: id}
+	}
+	return app, nil
+}
+
+// CreateOAuth2ApplicationOptions holds options to create an oauth2 application
+type CreateOAuth2ApplicationOptions struct {
+	Name               string
+	UserID             int64
+	ConfidentialClient bool
+	RedirectURIs       []string
+}
+
+// CreateOAuth2Application inserts a new oauth2 application
+func CreateOAuth2Application(ctx context.Context, opts CreateOAuth2ApplicationOptions) (*OAuth2Application, error) {
+	clientID := uuid.New().String()
+	app := &OAuth2Application{
+		UID:                opts.UserID,
+		Name:               opts.Name,
+		ClientID:           clientID,
+		RedirectURIs:       opts.RedirectURIs,
+		ConfidentialClient: opts.ConfidentialClient,
+	}
+	if err := db.Insert(ctx, 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
+	ConfidentialClient bool
+	RedirectURIs       []string
+}
+
+// UpdateOAuth2Application updates an oauth2 application
+func UpdateOAuth2Application(ctx context.Context, opts UpdateOAuth2ApplicationOptions) (*OAuth2Application, error) {
+	ctx, committer, err := db.TxContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer committer.Close()
+
+	app, err := GetOAuth2ApplicationByID(ctx, opts.ID)
+	if err != nil {
+		return nil, err
+	}
+	if app.UID != opts.UserID {
+		return nil, errors.New("UID mismatch")
+	}
+	builtinApps := BuiltinApplications()
+	if _, builtin := builtinApps[app.ClientID]; builtin {
+		return nil, fmt.Errorf("failed to edit OAuth2 application: application is locked: %s", app.ClientID)
+	}
+
+	app.Name = opts.Name
+	app.RedirectURIs = opts.RedirectURIs
+	app.ConfidentialClient = opts.ConfidentialClient
+
+	if err = updateOAuth2Application(ctx, app); err != nil {
+		return nil, err
+	}
+	app.ClientSecret = ""
+
+	return app, committer.Commit()
+}
+
+func updateOAuth2Application(ctx context.Context, app *OAuth2Application) error {
+	if _, err := db.GetEngine(ctx).ID(app.ID).UseBool("confidential_client").Update(app); err != nil {
+		return err
+	}
+	return nil
+}
+
+func deleteOAuth2Application(ctx context.Context, id, userid int64) error {
+	sess := db.GetEngine(ctx)
+	// the userid could be 0 if the app is instance-wide
+	if deleted, err := sess.Where(builder.Eq{"id": id, "uid": userid}).Delete(&OAuth2Application{}); err != nil {
+		return err
+	} else if deleted == 0 {
+		return ErrOAuthApplicationNotFound{ID: id}
+	}
+	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, len(codes))
+	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(ctx context.Context, id, userid int64) error {
+	ctx, committer, err := db.TxContext(ctx)
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+	app, err := GetOAuth2ApplicationByID(ctx, id)
+	if err != nil {
+		return err
+	}
+	builtinApps := BuiltinApplications()
+	if _, builtin := builtinApps[app.ClientID]; builtin {
+		return fmt.Errorf("failed to delete OAuth2 application: application is locked: %s", app.ClientID)
+	}
+	if err := deleteOAuth2Application(ctx, id, userid); err != nil {
+		return err
+	}
+	return committer.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          timeutil.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) (*url.URL, error) {
+	redirect, err := url.Parse(code.RedirectURI)
+	if err != nil {
+		return nil, err
+	}
+	q := redirect.Query()
+	if state != "" {
+		q.Set("state", state)
+	}
+	q.Set("code", code.Code)
+	redirect.RawQuery = q.Encode()
+	return redirect, err
+}
+
+// Invalidate deletes the auth code from the database to invalidate this code
+func (code *OAuth2AuthorizationCode) Invalidate(ctx context.Context) error {
+	_, err := db.GetEngine(ctx).ID(code.ID).NoAutoCondition().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 {
+	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(ctx context.Context, code string) (auth *OAuth2AuthorizationCode, err error) {
+	auth = new(OAuth2AuthorizationCode)
+	if has, err := db.GetEngine(ctx).Where("code = ?", code).Get(auth); err != nil {
+		return nil, err
+	} else if !has {
+		return nil, nil
+	}
+	auth.Grant = new(OAuth2Grant)
+	if has, err := db.GetEngine(ctx).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 specific application to access resources
+type OAuth2Grant struct {
+	ID            int64              `xorm:"pk autoincr"`
+	UserID        int64              `xorm:"INDEX unique(user_application)"`
+	Application   *OAuth2Application `xorm:"-"`
+	ApplicationID int64              `xorm:"INDEX unique(user_application)"`
+	Counter       int64              `xorm:"NOT NULL DEFAULT 1"`
+	Scope         string             `xorm:"TEXT"`
+	Nonce         string             `xorm:"TEXT"`
+	CreatedUnix   timeutil.TimeStamp `xorm:"created"`
+	UpdatedUnix   timeutil.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 database
+func (grant *OAuth2Grant) GenerateNewAuthorizationCode(ctx context.Context, redirectURI, codeChallenge, codeChallengeMethod string) (code *OAuth2AuthorizationCode, err error) {
+	rBytes, err := util.CryptoRandomBytes(32)
+	if err != nil {
+		return &OAuth2AuthorizationCode{}, err
+	}
+	// Add a prefix to the base32, this is in order to make it easier
+	// for code scanners to grab sensitive tokens.
+	codeSecret := "gta_" + base32Lower.EncodeToString(rBytes)
+
+	code = &OAuth2AuthorizationCode{
+		Grant:               grant,
+		GrantID:             grant.ID,
+		RedirectURI:         redirectURI,
+		Code:                codeSecret,
+		CodeChallenge:       codeChallenge,
+		CodeChallengeMethod: codeChallengeMethod,
+	}
+	if err := db.Insert(ctx, code); err != nil {
+		return nil, err
+	}
+	return code, nil
+}
+
+// IncreaseCounter increases the counter and updates the grant
+func (grant *OAuth2Grant) IncreaseCounter(ctx context.Context) error {
+	_, err := db.GetEngine(ctx).ID(grant.ID).Incr("counter").Update(new(OAuth2Grant))
+	if err != nil {
+		return err
+	}
+	updatedGrant, err := GetOAuth2GrantByID(ctx, grant.ID)
+	if err != nil {
+		return err
+	}
+	grant.Counter = updatedGrant.Counter
+	return nil
+}
+
+// ScopeContains returns true if the grant scope contains the specified scope
+func (grant *OAuth2Grant) ScopeContains(scope string) bool {
+	for _, currentScope := range strings.Split(grant.Scope, " ") {
+		if scope == currentScope {
+			return true
+		}
+	}
+	return false
+}
+
+// SetNonce updates the current nonce value of a grant
+func (grant *OAuth2Grant) SetNonce(ctx context.Context, nonce string) error {
+	grant.Nonce = nonce
+	_, err := db.GetEngine(ctx).ID(grant.ID).Cols("nonce").Update(grant)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// GetOAuth2GrantByID returns the grant with the given ID
+func GetOAuth2GrantByID(ctx context.Context, id int64) (grant *OAuth2Grant, err error) {
+	grant = new(OAuth2Grant)
+	if has, err := db.GetEngine(ctx).ID(id).Get(grant); err != nil {
+		return nil, err
+	} else if !has {
+		return nil, nil
+	}
+	return grant, err
+}
+
+// GetOAuth2GrantsByUserID lists all grants of a certain user
+func GetOAuth2GrantsByUserID(ctx context.Context, uid int64) ([]*OAuth2Grant, error) {
+	type joinedOAuth2Grant struct {
+		Grant       *OAuth2Grant       `xorm:"extends"`
+		Application *OAuth2Application `xorm:"extends"`
+	}
+	var results *xorm.Rows
+	var err error
+	if results, err = db.GetEngine(ctx).
+		Table("oauth2_grant").
+		Where("user_id = ?", uid).
+		Join("INNER", "oauth2_application", "application_id = oauth2_application.id").
+		Rows(new(joinedOAuth2Grant)); err != nil {
+		return nil, err
+	}
+	defer results.Close()
+	grants := make([]*OAuth2Grant, 0)
+	for results.Next() {
+		joinedGrant := new(joinedOAuth2Grant)
+		if err := results.Scan(joinedGrant); err != nil {
+			return nil, err
+		}
+		joinedGrant.Grant.Application = joinedGrant.Application
+		grants = append(grants, joinedGrant.Grant)
+	}
+	return grants, nil
+}
+
+// RevokeOAuth2Grant deletes the grant with grantID and userID
+func RevokeOAuth2Grant(ctx context.Context, grantID, userID int64) error {
+	_, err := db.GetEngine(ctx).Where(builder.Eq{"id": grantID, "user_id": userID}).Delete(&OAuth2Grant{})
+	return err
+}
+
+// ErrOAuthClientIDInvalid will be thrown if client id cannot be found
+type ErrOAuthClientIDInvalid struct {
+	ClientID string
+}
+
+// IsErrOauthClientIDInvalid checks if an error is a ErrOAuthClientIDInvalid.
+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)
+}
+
+// Unwrap unwraps this as a ErrNotExist err
+func (err ErrOAuthClientIDInvalid) Unwrap() error {
+	return util.ErrNotExist
+}
+
+// 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)
+}
+
+// Unwrap unwraps this as a ErrNotExist err
+func (err ErrOAuthApplicationNotFound) Unwrap() error {
+	return util.ErrNotExist
+}
+
+// GetActiveOAuth2SourceByName returns a OAuth2 AuthSource based on the given name
+func GetActiveOAuth2SourceByName(ctx context.Context, name string) (*Source, error) {
+	authSource := new(Source)
+	has, err := db.GetEngine(ctx).Where("name = ? and type = ? and is_active = ?", name, OAuth2, true).Get(authSource)
+	if err != nil {
+		return nil, err
+	}
+
+	if !has {
+		return nil, fmt.Errorf("oauth2 source not found, name: %q", name)
+	}
+
+	return authSource, nil
+}
+
+func DeleteOAuth2RelictsByUserID(ctx context.Context, userID int64) error {
+	deleteCond := builder.Select("id").From("oauth2_grant").Where(builder.Eq{"oauth2_grant.user_id": userID})
+
+	if _, err := db.GetEngine(ctx).In("grant_id", deleteCond).
+		Delete(&OAuth2AuthorizationCode{}); err != nil {
+		return err
+	}
+
+	if err := db.DeleteBeans(ctx,
+		&OAuth2Application{UID: userID},
+		&OAuth2Grant{UserID: userID},
+	); err != nil {
+		return fmt.Errorf("DeleteBeans: %w", err)
+	}
+
+	return nil
+}
+
+// CountOrphanedOAuth2Applications returns the amount of orphaned OAuth2 applications.
+func CountOrphanedOAuth2Applications(ctx context.Context) (int64, error) {
+	return db.GetEngine(ctx).
+		Table("`oauth2_application`").
+		Join("LEFT", "`user`", "`oauth2_application`.`uid` = `user`.`id`").
+		Where(builder.IsNull{"`user`.id"}).
+		Where(builder.Neq{"uid": 0}). // exclude instance-wide admin applications
+		Where(builder.NotIn("`oauth2_application`.`client_id`", BuiltinApplicationsClientIDs())).
+		Select("COUNT(`oauth2_application`.`id`)").
+		Count()
+}
+
+// DeleteOrphanedOAuth2Applications deletes orphaned OAuth2 applications.
+func DeleteOrphanedOAuth2Applications(ctx context.Context) (int64, error) {
+	subQuery := builder.Select("`oauth2_application`.id").
+		From("`oauth2_application`").
+		Join("LEFT", "`user`", "`oauth2_application`.`uid` = `user`.`id`").
+		Where(builder.IsNull{"`user`.id"}).
+		Where(builder.Neq{"uid": 0}). // exclude instance-wide admin applications
+		Where(builder.NotIn("`oauth2_application`.`client_id`", BuiltinApplicationsClientIDs()))
+
+	b := builder.Delete(builder.In("id", subQuery)).From("`oauth2_application`")
+	_, err := db.GetEngine(ctx).Exec(b)
+	return -1, err
+}
diff --git a/models/auth/oauth2_list.go b/models/auth/oauth2_list.go
new file mode 100644
index 0000000..c55f10b
--- /dev/null
+++ b/models/auth/oauth2_list.go
@@ -0,0 +1,32 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"code.gitea.io/gitea/models/db"
+
+	"xorm.io/builder"
+)
+
+type FindOAuth2ApplicationsOptions struct {
+	db.ListOptions
+	// OwnerID is the user id or org id of the owner of the application
+	OwnerID int64
+	// find global applications, if true, then OwnerID will be igonred
+	IsGlobal bool
+}
+
+func (opts FindOAuth2ApplicationsOptions) ToConds() builder.Cond {
+	conds := builder.NewCond()
+	if opts.IsGlobal {
+		conds = conds.And(builder.Eq{"uid": 0})
+	} else if opts.OwnerID != 0 {
+		conds = conds.And(builder.Eq{"uid": opts.OwnerID})
+	}
+	return conds
+}
+
+func (opts FindOAuth2ApplicationsOptions) ToOrders() string {
+	return "id DESC"
+}
diff --git a/models/auth/oauth2_test.go b/models/auth/oauth2_test.go
new file mode 100644
index 0000000..9b562c8
--- /dev/null
+++ b/models/auth/oauth2_test.go
@@ -0,0 +1,300 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth_test
+
+import (
+	"path/filepath"
+	"slices"
+	"testing"
+
+	auth_model "code.gitea.io/gitea/models/auth"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestOAuth2Application_GenerateClientSecret(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	app := unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Application{ID: 1})
+	secret, err := app.GenerateClientSecret(db.DefaultContext)
+	require.NoError(t, err)
+	assert.NotEmpty(t, secret)
+	unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Application{ID: 1, ClientSecret: app.ClientSecret})
+}
+
+func BenchmarkOAuth2Application_GenerateClientSecret(b *testing.B) {
+	require.NoError(b, unittest.PrepareTestDatabase())
+	app := unittest.AssertExistsAndLoadBean(b, &auth_model.OAuth2Application{ID: 1})
+	for i := 0; i < b.N; i++ {
+		_, _ = app.GenerateClientSecret(db.DefaultContext)
+	}
+}
+
+func TestOAuth2Application_ContainsRedirectURI(t *testing.T) {
+	app := &auth_model.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_ContainsRedirectURI_WithPort(t *testing.T) {
+	app := &auth_model.OAuth2Application{
+		RedirectURIs:       []string{"http://127.0.0.1/", "http://::1/", "http://192.168.0.1/", "http://intranet/", "https://127.0.0.1/"},
+		ConfidentialClient: false,
+	}
+
+	// http loopback uris should ignore port
+	// https://datatracker.ietf.org/doc/html/rfc8252#section-7.3
+	assert.True(t, app.ContainsRedirectURI("http://127.0.0.1:3456/"))
+	assert.True(t, app.ContainsRedirectURI("http://127.0.0.1/"))
+	assert.True(t, app.ContainsRedirectURI("http://[::1]:3456/"))
+
+	// not http
+	assert.False(t, app.ContainsRedirectURI("https://127.0.0.1:3456/"))
+	// not loopback
+	assert.False(t, app.ContainsRedirectURI("http://192.168.0.1:9954/"))
+	assert.False(t, app.ContainsRedirectURI("http://intranet:3456/"))
+	// unparsable
+	assert.False(t, app.ContainsRedirectURI(":"))
+}
+
+func TestOAuth2Application_ContainsRedirect_Slash(t *testing.T) {
+	app := &auth_model.OAuth2Application{RedirectURIs: []string{"http://127.0.0.1"}}
+	assert.True(t, app.ContainsRedirectURI("http://127.0.0.1"))
+	assert.True(t, app.ContainsRedirectURI("http://127.0.0.1/"))
+	assert.False(t, app.ContainsRedirectURI("http://127.0.0.1/other"))
+
+	app = &auth_model.OAuth2Application{RedirectURIs: []string{"http://127.0.0.1/"}}
+	assert.True(t, app.ContainsRedirectURI("http://127.0.0.1"))
+	assert.True(t, app.ContainsRedirectURI("http://127.0.0.1/"))
+	assert.False(t, app.ContainsRedirectURI("http://127.0.0.1/other"))
+}
+
+func TestOAuth2Application_ValidateClientSecret(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	app := unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Application{ID: 1})
+	secret, err := app.GenerateClientSecret(db.DefaultContext)
+	require.NoError(t, err)
+	assert.True(t, app.ValidateClientSecret([]byte(secret)))
+	assert.False(t, app.ValidateClientSecret([]byte("fewijfowejgfiowjeoifew")))
+}
+
+func TestGetOAuth2ApplicationByClientID(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	app, err := auth_model.GetOAuth2ApplicationByClientID(db.DefaultContext, "da7da3ba-9a13-4167-856f-3899de0b0138")
+	require.NoError(t, err)
+	assert.Equal(t, "da7da3ba-9a13-4167-856f-3899de0b0138", app.ClientID)
+
+	app, err = auth_model.GetOAuth2ApplicationByClientID(db.DefaultContext, "invalid client id")
+	require.Error(t, err)
+	assert.Nil(t, app)
+}
+
+func TestCreateOAuth2Application(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	app, err := auth_model.CreateOAuth2Application(db.DefaultContext, auth_model.CreateOAuth2ApplicationOptions{Name: "newapp", UserID: 1})
+	require.NoError(t, err)
+	assert.Equal(t, "newapp", app.Name)
+	assert.Len(t, app.ClientID, 36)
+	unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Application{Name: "newapp"})
+}
+
+func TestOAuth2Application_TableName(t *testing.T) {
+	assert.Equal(t, "oauth2_application", new(auth_model.OAuth2Application).TableName())
+}
+
+func TestOAuth2Application_GetGrantByUserID(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	app := unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Application{ID: 1})
+	grant, err := app.GetGrantByUserID(db.DefaultContext, 1)
+	require.NoError(t, err)
+	assert.Equal(t, int64(1), grant.UserID)
+
+	grant, err = app.GetGrantByUserID(db.DefaultContext, 34923458)
+	require.NoError(t, err)
+	assert.Nil(t, grant)
+}
+
+func TestOAuth2Application_CreateGrant(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	app := unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Application{ID: 1})
+	grant, err := app.CreateGrant(db.DefaultContext, 2, "")
+	require.NoError(t, err)
+	assert.NotNil(t, grant)
+	assert.Equal(t, int64(2), grant.UserID)
+	assert.Equal(t, int64(1), grant.ApplicationID)
+	assert.Equal(t, "", grant.Scope)
+}
+
+//////////////////// Grant
+
+func TestGetOAuth2GrantByID(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	grant, err := auth_model.GetOAuth2GrantByID(db.DefaultContext, 1)
+	require.NoError(t, err)
+	assert.Equal(t, int64(1), grant.ID)
+
+	grant, err = auth_model.GetOAuth2GrantByID(db.DefaultContext, 34923458)
+	require.NoError(t, err)
+	assert.Nil(t, grant)
+}
+
+func TestOAuth2Grant_IncreaseCounter(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	grant := unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Grant{ID: 1, Counter: 1})
+	require.NoError(t, grant.IncreaseCounter(db.DefaultContext))
+	assert.Equal(t, int64(2), grant.Counter)
+	unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Grant{ID: 1, Counter: 2})
+}
+
+func TestOAuth2Grant_ScopeContains(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	grant := unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Grant{ID: 1, Scope: "openid profile"})
+	assert.True(t, grant.ScopeContains("openid"))
+	assert.True(t, grant.ScopeContains("profile"))
+	assert.False(t, grant.ScopeContains("profil"))
+	assert.False(t, grant.ScopeContains("profile2"))
+}
+
+func TestOAuth2Grant_GenerateNewAuthorizationCode(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	grant := unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2Grant{ID: 1})
+	code, err := grant.GenerateNewAuthorizationCode(db.DefaultContext, "https://example2.com/callback", "CjvyTLSdR47G5zYenDA-eDWW4lRrO8yvjcWwbD_deOg", "S256")
+	require.NoError(t, err)
+	assert.NotNil(t, code)
+	assert.Greater(t, len(code.Code), 32) // secret length > 32
+}
+
+func TestOAuth2Grant_TableName(t *testing.T) {
+	assert.Equal(t, "oauth2_grant", new(auth_model.OAuth2Grant).TableName())
+}
+
+func TestGetOAuth2GrantsByUserID(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	result, err := auth_model.GetOAuth2GrantsByUserID(db.DefaultContext, 1)
+	require.NoError(t, err)
+	assert.Len(t, result, 1)
+	assert.Equal(t, int64(1), result[0].ID)
+	assert.Equal(t, result[0].ApplicationID, result[0].Application.ID)
+
+	result, err = auth_model.GetOAuth2GrantsByUserID(db.DefaultContext, 34134)
+	require.NoError(t, err)
+	assert.Empty(t, result)
+}
+
+func TestRevokeOAuth2Grant(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	require.NoError(t, auth_model.RevokeOAuth2Grant(db.DefaultContext, 1, 1))
+	unittest.AssertNotExistsBean(t, &auth_model.OAuth2Grant{ID: 1, UserID: 1})
+}
+
+//////////////////// Authorization Code
+
+func TestGetOAuth2AuthorizationByCode(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	code, err := auth_model.GetOAuth2AuthorizationByCode(db.DefaultContext, "authcode")
+	require.NoError(t, err)
+	assert.NotNil(t, code)
+	assert.Equal(t, "authcode", code.Code)
+	assert.Equal(t, int64(1), code.ID)
+
+	code, err = auth_model.GetOAuth2AuthorizationByCode(db.DefaultContext, "does not exist")
+	require.NoError(t, err)
+	assert.Nil(t, code)
+}
+
+func TestOAuth2AuthorizationCode_ValidateCodeChallenge(t *testing.T) {
+	// test plain
+	code := &auth_model.OAuth2AuthorizationCode{
+		CodeChallengeMethod: "plain",
+		CodeChallenge:       "test123",
+	}
+	assert.True(t, code.ValidateCodeChallenge("test123"))
+	assert.False(t, code.ValidateCodeChallenge("ierwgjoergjio"))
+
+	// test S256
+	code = &auth_model.OAuth2AuthorizationCode{
+		CodeChallengeMethod: "S256",
+		CodeChallenge:       "CjvyTLSdR47G5zYenDA-eDWW4lRrO8yvjcWwbD_deOg",
+	}
+	assert.True(t, code.ValidateCodeChallenge("N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt"))
+	assert.False(t, code.ValidateCodeChallenge("wiogjerogorewngoenrgoiuenorg"))
+
+	// test unknown
+	code = &auth_model.OAuth2AuthorizationCode{
+		CodeChallengeMethod: "monkey",
+		CodeChallenge:       "foiwgjioriogeiogjerger",
+	}
+	assert.False(t, code.ValidateCodeChallenge("foiwgjioriogeiogjerger"))
+
+	// test no code challenge
+	code = &auth_model.OAuth2AuthorizationCode{
+		CodeChallengeMethod: "",
+		CodeChallenge:       "foierjiogerogerg",
+	}
+	assert.True(t, code.ValidateCodeChallenge(""))
+}
+
+func TestOAuth2AuthorizationCode_GenerateRedirectURI(t *testing.T) {
+	code := &auth_model.OAuth2AuthorizationCode{
+		RedirectURI: "https://example.com/callback",
+		Code:        "thecode",
+	}
+
+	redirect, err := code.GenerateRedirectURI("thestate")
+	require.NoError(t, err)
+	assert.Equal(t, "https://example.com/callback?code=thecode&state=thestate", redirect.String())
+
+	redirect, err = code.GenerateRedirectURI("")
+	require.NoError(t, err)
+	assert.Equal(t, "https://example.com/callback?code=thecode", redirect.String())
+}
+
+func TestOAuth2AuthorizationCode_Invalidate(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	code := unittest.AssertExistsAndLoadBean(t, &auth_model.OAuth2AuthorizationCode{Code: "authcode"})
+	require.NoError(t, code.Invalidate(db.DefaultContext))
+	unittest.AssertNotExistsBean(t, &auth_model.OAuth2AuthorizationCode{Code: "authcode"})
+}
+
+func TestOAuth2AuthorizationCode_TableName(t *testing.T) {
+	assert.Equal(t, "oauth2_authorization_code", new(auth_model.OAuth2AuthorizationCode).TableName())
+}
+
+func TestBuiltinApplicationsClientIDs(t *testing.T) {
+	clientIDs := auth_model.BuiltinApplicationsClientIDs()
+	slices.Sort(clientIDs)
+	assert.EqualValues(t, []string{"a4792ccc-144e-407e-86c9-5e7d8d9c3269", "d57cb8c4-630c-4168-8324-ec79935e18d4", "e90ee53c-94e2-48ac-9358-a874fb9e0662"}, clientIDs)
+}
+
+func TestOrphanedOAuth2Applications(t *testing.T) {
+	defer unittest.OverrideFixtures(
+		unittest.FixturesOptions{
+			Dir:  filepath.Join(setting.AppWorkPath, "models/fixtures/"),
+			Base: setting.AppWorkPath,
+			Dirs: []string{"models/auth/TestOrphanedOAuth2Applications/"},
+		},
+	)()
+	require.NoError(t, unittest.PrepareTestDatabase())
+
+	count, err := auth_model.CountOrphanedOAuth2Applications(db.DefaultContext)
+	require.NoError(t, err)
+	assert.EqualValues(t, 1, count)
+	unittest.AssertExistsIf(t, true, &auth_model.OAuth2Application{ID: 1002})
+
+	_, err = auth_model.DeleteOrphanedOAuth2Applications(db.DefaultContext)
+	require.NoError(t, err)
+
+	count, err = auth_model.CountOrphanedOAuth2Applications(db.DefaultContext)
+	require.NoError(t, err)
+	assert.EqualValues(t, 0, count)
+	unittest.AssertExistsIf(t, false, &auth_model.OAuth2Application{ID: 1002})
+	unittest.AssertExistsIf(t, true, &auth_model.OAuth2Application{ID: 1003})
+}
diff --git a/models/auth/session.go b/models/auth/session.go
new file mode 100644
index 0000000..75a205f
--- /dev/null
+++ b/models/auth/session.go
@@ -0,0 +1,120 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"context"
+	"fmt"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/builder"
+)
+
+// Session represents a session compatible for go-chi session
+type Session struct {
+	Key    string             `xorm:"pk CHAR(16)"` // has to be Key to match with go-chi/session
+	Data   []byte             `xorm:"BLOB"`        // on MySQL this has a maximum size of 64Kb - this may need to be increased
+	Expiry timeutil.TimeStamp // has to be Expiry to match with go-chi/session
+}
+
+func init() {
+	db.RegisterModel(new(Session))
+}
+
+// UpdateSession updates the session with provided id
+func UpdateSession(ctx context.Context, key string, data []byte) error {
+	_, err := db.GetEngine(ctx).ID(key).Update(&Session{
+		Data:   data,
+		Expiry: timeutil.TimeStampNow(),
+	})
+	return err
+}
+
+// ReadSession reads the data for the provided session
+func ReadSession(ctx context.Context, key string) (*Session, error) {
+	ctx, committer, err := db.TxContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer committer.Close()
+
+	session, exist, err := db.Get[Session](ctx, builder.Eq{"`key`": key})
+	if err != nil {
+		return nil, err
+	} else if !exist {
+		session = &Session{
+			Key:    key,
+			Expiry: timeutil.TimeStampNow(),
+		}
+		if err := db.Insert(ctx, session); err != nil {
+			return nil, err
+		}
+	}
+
+	return session, committer.Commit()
+}
+
+// ExistSession checks if a session exists
+func ExistSession(ctx context.Context, key string) (bool, error) {
+	return db.Exist[Session](ctx, builder.Eq{"`key`": key})
+}
+
+// DestroySession destroys a session
+func DestroySession(ctx context.Context, key string) error {
+	_, err := db.GetEngine(ctx).Delete(&Session{
+		Key: key,
+	})
+	return err
+}
+
+// RegenerateSession regenerates a session from the old id
+func RegenerateSession(ctx context.Context, oldKey, newKey string) (*Session, error) {
+	ctx, committer, err := db.TxContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer committer.Close()
+
+	if has, err := db.Exist[Session](ctx, builder.Eq{"`key`": newKey}); err != nil {
+		return nil, err
+	} else if has {
+		return nil, fmt.Errorf("session Key: %s already exists", newKey)
+	}
+
+	if has, err := db.Exist[Session](ctx, builder.Eq{"`key`": oldKey}); err != nil {
+		return nil, err
+	} else if !has {
+		if err := db.Insert(ctx, &Session{
+			Key:    oldKey,
+			Expiry: timeutil.TimeStampNow(),
+		}); err != nil {
+			return nil, err
+		}
+	}
+
+	if _, err := db.Exec(ctx, "UPDATE "+db.TableName(&Session{})+" SET `key` = ? WHERE `key`=?", newKey, oldKey); err != nil {
+		return nil, err
+	}
+
+	s, _, err := db.Get[Session](ctx, builder.Eq{"`key`": newKey})
+	if err != nil {
+		// is not exist, it should be impossible
+		return nil, err
+	}
+
+	return s, committer.Commit()
+}
+
+// CountSessions returns the number of sessions
+func CountSessions(ctx context.Context) (int64, error) {
+	return db.GetEngine(ctx).Count(&Session{})
+}
+
+// CleanupSessions cleans up expired sessions
+func CleanupSessions(ctx context.Context, maxLifetime int64) error {
+	_, err := db.GetEngine(ctx).Where("expiry <= ?", timeutil.TimeStampNow().Add(-maxLifetime)).Delete(&Session{})
+	return err
+}
diff --git a/models/auth/session_test.go b/models/auth/session_test.go
new file mode 100644
index 0000000..3b57239
--- /dev/null
+++ b/models/auth/session_test.go
@@ -0,0 +1,143 @@
+// Copyright 2023 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth_test
+
+import (
+	"testing"
+	"time"
+
+	"code.gitea.io/gitea/models/auth"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestAuthSession(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	defer timeutil.MockUnset()
+
+	key := "I-Like-Free-Software"
+
+	t.Run("Create Session", func(t *testing.T) {
+		// Ensure it doesn't exist.
+		ok, err := auth.ExistSession(db.DefaultContext, key)
+		require.NoError(t, err)
+		assert.False(t, ok)
+
+		preCount, err := auth.CountSessions(db.DefaultContext)
+		require.NoError(t, err)
+
+		now := time.Date(2021, 1, 1, 0, 0, 0, 0, time.UTC)
+		timeutil.MockSet(now)
+
+		// New session is created.
+		sess, err := auth.ReadSession(db.DefaultContext, key)
+		require.NoError(t, err)
+		assert.EqualValues(t, key, sess.Key)
+		assert.Empty(t, sess.Data)
+		assert.EqualValues(t, now.Unix(), sess.Expiry)
+
+		// Ensure it exists.
+		ok, err = auth.ExistSession(db.DefaultContext, key)
+		require.NoError(t, err)
+		assert.True(t, ok)
+
+		// Ensure the session is taken into account for count..
+		postCount, err := auth.CountSessions(db.DefaultContext)
+		require.NoError(t, err)
+		assert.Greater(t, postCount, preCount)
+	})
+
+	t.Run("Update session", func(t *testing.T) {
+		data := []byte{0xba, 0xdd, 0xc0, 0xde}
+		now := time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+		timeutil.MockSet(now)
+
+		// Update session.
+		err := auth.UpdateSession(db.DefaultContext, key, data)
+		require.NoError(t, err)
+
+		timeutil.MockSet(time.Date(2021, 1, 1, 0, 0, 0, 0, time.UTC))
+
+		// Read updated session.
+		// Ensure data is updated and expiry is set from the update session call.
+		sess, err := auth.ReadSession(db.DefaultContext, key)
+		require.NoError(t, err)
+		assert.EqualValues(t, key, sess.Key)
+		assert.EqualValues(t, data, sess.Data)
+		assert.EqualValues(t, now.Unix(), sess.Expiry)
+
+		timeutil.MockSet(now)
+	})
+
+	t.Run("Delete session", func(t *testing.T) {
+		// Ensure it't exist.
+		ok, err := auth.ExistSession(db.DefaultContext, key)
+		require.NoError(t, err)
+		assert.True(t, ok)
+
+		preCount, err := auth.CountSessions(db.DefaultContext)
+		require.NoError(t, err)
+
+		err = auth.DestroySession(db.DefaultContext, key)
+		require.NoError(t, err)
+
+		// Ensure it doesn't exists.
+		ok, err = auth.ExistSession(db.DefaultContext, key)
+		require.NoError(t, err)
+		assert.False(t, ok)
+
+		// Ensure the session is taken into account for count..
+		postCount, err := auth.CountSessions(db.DefaultContext)
+		require.NoError(t, err)
+		assert.Less(t, postCount, preCount)
+	})
+
+	t.Run("Cleanup sessions", func(t *testing.T) {
+		timeutil.MockSet(time.Date(2023, 1, 1, 0, 0, 0, 0, time.UTC))
+
+		_, err := auth.ReadSession(db.DefaultContext, "sess-1")
+		require.NoError(t, err)
+
+		// One minute later.
+		timeutil.MockSet(time.Date(2023, 1, 1, 0, 1, 0, 0, time.UTC))
+		_, err = auth.ReadSession(db.DefaultContext, "sess-2")
+		require.NoError(t, err)
+
+		// 5 minutes, shouldn't clean up anything.
+		err = auth.CleanupSessions(db.DefaultContext, 5*60)
+		require.NoError(t, err)
+
+		ok, err := auth.ExistSession(db.DefaultContext, "sess-1")
+		require.NoError(t, err)
+		assert.True(t, ok)
+
+		ok, err = auth.ExistSession(db.DefaultContext, "sess-2")
+		require.NoError(t, err)
+		assert.True(t, ok)
+
+		// 1 minute, should clean up sess-1.
+		err = auth.CleanupSessions(db.DefaultContext, 60)
+		require.NoError(t, err)
+
+		ok, err = auth.ExistSession(db.DefaultContext, "sess-1")
+		require.NoError(t, err)
+		assert.False(t, ok)
+
+		ok, err = auth.ExistSession(db.DefaultContext, "sess-2")
+		require.NoError(t, err)
+		assert.True(t, ok)
+
+		// Now, should clean up sess-2.
+		err = auth.CleanupSessions(db.DefaultContext, 0)
+		require.NoError(t, err)
+
+		ok, err = auth.ExistSession(db.DefaultContext, "sess-2")
+		require.NoError(t, err)
+		assert.False(t, ok)
+	})
+}
diff --git a/models/auth/source.go b/models/auth/source.go
new file mode 100644
index 0000000..d03d497
--- /dev/null
+++ b/models/auth/source.go
@@ -0,0 +1,412 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/optional"
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/util"
+
+	"xorm.io/builder"
+	"xorm.io/xorm"
+	"xorm.io/xorm/convert"
+)
+
+// Type represents an login type.
+type Type int
+
+// Note: new type must append to the end of list to maintain compatibility.
+const (
+	NoType Type = iota
+	Plain       // 1
+	LDAP        // 2
+	SMTP        // 3
+	PAM         // 4
+	DLDAP       // 5
+	OAuth2      // 6
+	SSPI        // 7
+	Remote      // 8
+)
+
+// String returns the string name of the LoginType
+func (typ Type) String() string {
+	return Names[typ]
+}
+
+// Int returns the int value of the LoginType
+func (typ Type) Int() int {
+	return int(typ)
+}
+
+// Names contains the name of LoginType values.
+var Names = map[Type]string{
+	LDAP:   "LDAP (via BindDN)",
+	DLDAP:  "LDAP (simple auth)", // Via direct bind
+	SMTP:   "SMTP",
+	PAM:    "PAM",
+	OAuth2: "OAuth2",
+	SSPI:   "SPNEGO with SSPI",
+	Remote: "Remote",
+}
+
+// Config represents login config as far as the db is concerned
+type Config interface {
+	convert.Conversion
+}
+
+// SkipVerifiable configurations provide a IsSkipVerify to check if SkipVerify is set
+type SkipVerifiable interface {
+	IsSkipVerify() bool
+}
+
+// HasTLSer configurations provide a HasTLS to check if TLS can be enabled
+type HasTLSer interface {
+	HasTLS() bool
+}
+
+// UseTLSer configurations provide a HasTLS to check if TLS is enabled
+type UseTLSer interface {
+	UseTLS() bool
+}
+
+// SSHKeyProvider configurations provide ProvidesSSHKeys to check if they provide SSHKeys
+type SSHKeyProvider interface {
+	ProvidesSSHKeys() bool
+}
+
+// RegisterableSource configurations provide RegisterSource which needs to be run on creation
+type RegisterableSource interface {
+	RegisterSource() error
+	UnregisterSource() error
+}
+
+var registeredConfigs = map[Type]func() Config{}
+
+// RegisterTypeConfig register a config for a provided type
+func RegisterTypeConfig(typ Type, exemplar Config) {
+	if reflect.TypeOf(exemplar).Kind() == reflect.Ptr {
+		// Pointer:
+		registeredConfigs[typ] = func() Config {
+			return reflect.New(reflect.ValueOf(exemplar).Elem().Type()).Interface().(Config)
+		}
+		return
+	}
+
+	// Not a Pointer
+	registeredConfigs[typ] = func() Config {
+		return reflect.New(reflect.TypeOf(exemplar)).Elem().Interface().(Config)
+	}
+}
+
+// SourceSettable configurations can have their authSource set on them
+type SourceSettable interface {
+	SetAuthSource(*Source)
+}
+
+// Source represents an external way for authorizing users.
+type Source struct {
+	ID            int64 `xorm:"pk autoincr"`
+	Type          Type
+	Name          string             `xorm:"UNIQUE"`
+	IsActive      bool               `xorm:"INDEX NOT NULL DEFAULT false"`
+	IsSyncEnabled bool               `xorm:"INDEX NOT NULL DEFAULT false"`
+	Cfg           convert.Conversion `xorm:"TEXT"`
+
+	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
+	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
+}
+
+// TableName xorm will read the table name from this method
+func (Source) TableName() string {
+	return "login_source"
+}
+
+func init() {
+	db.RegisterModel(new(Source))
+}
+
+// BeforeSet is invoked from XORM before setting the value of a field of this object.
+func (source *Source) BeforeSet(colName string, val xorm.Cell) {
+	if colName == "type" {
+		typ := Type(db.Cell2Int64(val))
+		constructor, ok := registeredConfigs[typ]
+		if !ok {
+			return
+		}
+		source.Cfg = constructor()
+		if settable, ok := source.Cfg.(SourceSettable); ok {
+			settable.SetAuthSource(source)
+		}
+	}
+}
+
+// TypeName return name of this login source type.
+func (source *Source) TypeName() string {
+	return Names[source.Type]
+}
+
+// IsLDAP returns true of this source is of the LDAP type.
+func (source *Source) IsLDAP() bool {
+	return source.Type == LDAP
+}
+
+// IsDLDAP returns true of this source is of the DLDAP type.
+func (source *Source) IsDLDAP() bool {
+	return source.Type == DLDAP
+}
+
+// IsSMTP returns true of this source is of the SMTP type.
+func (source *Source) IsSMTP() bool {
+	return source.Type == SMTP
+}
+
+// IsPAM returns true of this source is of the PAM type.
+func (source *Source) IsPAM() bool {
+	return source.Type == PAM
+}
+
+// IsOAuth2 returns true of this source is of the OAuth2 type.
+func (source *Source) IsOAuth2() bool {
+	return source.Type == OAuth2
+}
+
+// IsSSPI returns true of this source is of the SSPI type.
+func (source *Source) IsSSPI() bool {
+	return source.Type == SSPI
+}
+
+func (source *Source) IsRemote() bool {
+	return source.Type == Remote
+}
+
+// HasTLS returns true of this source supports TLS.
+func (source *Source) HasTLS() bool {
+	hasTLSer, ok := source.Cfg.(HasTLSer)
+	return ok && hasTLSer.HasTLS()
+}
+
+// UseTLS returns true of this source is configured to use TLS.
+func (source *Source) UseTLS() bool {
+	useTLSer, ok := source.Cfg.(UseTLSer)
+	return ok && useTLSer.UseTLS()
+}
+
+// SkipVerify returns true if this source is configured to skip SSL
+// verification.
+func (source *Source) SkipVerify() bool {
+	skipVerifiable, ok := source.Cfg.(SkipVerifiable)
+	return ok && skipVerifiable.IsSkipVerify()
+}
+
+// CreateSource inserts a AuthSource in the DB if not already
+// existing with the given name.
+func CreateSource(ctx context.Context, source *Source) error {
+	has, err := db.GetEngine(ctx).Where("name=?", source.Name).Exist(new(Source))
+	if err != nil {
+		return err
+	} else if has {
+		return ErrSourceAlreadyExist{source.Name}
+	}
+	// Synchronization is only available with LDAP for now
+	if !source.IsLDAP() {
+		source.IsSyncEnabled = false
+	}
+
+	_, err = db.GetEngine(ctx).Insert(source)
+	if err != nil {
+		return err
+	}
+
+	if !source.IsActive {
+		return nil
+	}
+
+	if settable, ok := source.Cfg.(SourceSettable); ok {
+		settable.SetAuthSource(source)
+	}
+
+	registerableSource, ok := source.Cfg.(RegisterableSource)
+	if !ok {
+		return nil
+	}
+
+	err = registerableSource.RegisterSource()
+	if err != nil {
+		// remove the AuthSource in case of errors while registering configuration
+		if _, err := db.GetEngine(ctx).ID(source.ID).Delete(new(Source)); err != nil {
+			log.Error("CreateSource: Error while wrapOpenIDConnectInitializeError: %v", err)
+		}
+	}
+	return err
+}
+
+type FindSourcesOptions struct {
+	db.ListOptions
+	IsActive  optional.Option[bool]
+	LoginType Type
+}
+
+func (opts FindSourcesOptions) ToConds() builder.Cond {
+	conds := builder.NewCond()
+	if opts.IsActive.Has() {
+		conds = conds.And(builder.Eq{"is_active": opts.IsActive.Value()})
+	}
+	if opts.LoginType != NoType {
+		conds = conds.And(builder.Eq{"`type`": opts.LoginType})
+	}
+	return conds
+}
+
+// IsSSPIEnabled returns true if there is at least one activated login
+// source of type LoginSSPI
+func IsSSPIEnabled(ctx context.Context) bool {
+	exist, err := db.Exist[Source](ctx, FindSourcesOptions{
+		IsActive:  optional.Some(true),
+		LoginType: SSPI,
+	}.ToConds())
+	if err != nil {
+		log.Error("IsSSPIEnabled: failed to query active SSPI sources: %v", err)
+		return false
+	}
+	return exist
+}
+
+// GetSourceByID returns login source by given ID.
+func GetSourceByID(ctx context.Context, id int64) (*Source, error) {
+	source := new(Source)
+	if id == 0 {
+		source.Cfg = registeredConfigs[NoType]()
+		// Set this source to active
+		// FIXME: allow disabling of db based password authentication in future
+		source.IsActive = true
+		return source, nil
+	}
+
+	has, err := db.GetEngine(ctx).ID(id).Get(source)
+	if err != nil {
+		return nil, err
+	} else if !has {
+		return nil, ErrSourceNotExist{id}
+	}
+	return source, nil
+}
+
+func GetSourceByName(ctx context.Context, name string) (*Source, error) {
+	source := &Source{}
+	has, err := db.GetEngine(ctx).Where("name = ?", name).Get(source)
+	if err != nil {
+		return nil, err
+	} else if !has {
+		return nil, ErrSourceNotExist{}
+	}
+	return source, nil
+}
+
+// UpdateSource updates a Source record in DB.
+func UpdateSource(ctx context.Context, source *Source) error {
+	var originalSource *Source
+	if source.IsOAuth2() {
+		// keep track of the original values so we can restore in case of errors while registering OAuth2 providers
+		var err error
+		if originalSource, err = GetSourceByID(ctx, source.ID); err != nil {
+			return err
+		}
+	}
+
+	has, err := db.GetEngine(ctx).Where("name=? AND id!=?", source.Name, source.ID).Exist(new(Source))
+	if err != nil {
+		return err
+	} else if has {
+		return ErrSourceAlreadyExist{source.Name}
+	}
+
+	_, err = db.GetEngine(ctx).ID(source.ID).AllCols().Update(source)
+	if err != nil {
+		return err
+	}
+
+	if !source.IsActive {
+		return nil
+	}
+
+	if settable, ok := source.Cfg.(SourceSettable); ok {
+		settable.SetAuthSource(source)
+	}
+
+	registerableSource, ok := source.Cfg.(RegisterableSource)
+	if !ok {
+		return nil
+	}
+
+	err = registerableSource.RegisterSource()
+	if err != nil {
+		// restore original values since we cannot update the provider it self
+		if _, err := db.GetEngine(ctx).ID(source.ID).AllCols().Update(originalSource); err != nil {
+			log.Error("UpdateSource: Error while wrapOpenIDConnectInitializeError: %v", err)
+		}
+	}
+	return err
+}
+
+// ErrSourceNotExist represents a "SourceNotExist" kind of error.
+type ErrSourceNotExist struct {
+	ID int64
+}
+
+// IsErrSourceNotExist checks if an error is a ErrSourceNotExist.
+func IsErrSourceNotExist(err error) bool {
+	_, ok := err.(ErrSourceNotExist)
+	return ok
+}
+
+func (err ErrSourceNotExist) Error() string {
+	return fmt.Sprintf("login source does not exist [id: %d]", err.ID)
+}
+
+// Unwrap unwraps this as a ErrNotExist err
+func (err ErrSourceNotExist) Unwrap() error {
+	return util.ErrNotExist
+}
+
+// ErrSourceAlreadyExist represents a "SourceAlreadyExist" kind of error.
+type ErrSourceAlreadyExist struct {
+	Name string
+}
+
+// IsErrSourceAlreadyExist checks if an error is a ErrSourceAlreadyExist.
+func IsErrSourceAlreadyExist(err error) bool {
+	_, ok := err.(ErrSourceAlreadyExist)
+	return ok
+}
+
+func (err ErrSourceAlreadyExist) Error() string {
+	return fmt.Sprintf("login source already exists [name: %s]", err.Name)
+}
+
+// Unwrap unwraps this as a ErrExist err
+func (err ErrSourceAlreadyExist) Unwrap() error {
+	return util.ErrAlreadyExist
+}
+
+// ErrSourceInUse represents a "SourceInUse" kind of error.
+type ErrSourceInUse struct {
+	ID int64
+}
+
+// IsErrSourceInUse checks if an error is a ErrSourceInUse.
+func IsErrSourceInUse(err error) bool {
+	_, ok := err.(ErrSourceInUse)
+	return ok
+}
+
+func (err ErrSourceInUse) Error() string {
+	return fmt.Sprintf("login source is still used by some users [id: %d]", err.ID)
+}
diff --git a/models/auth/source_test.go b/models/auth/source_test.go
new file mode 100644
index 0000000..522fecc
--- /dev/null
+++ b/models/auth/source_test.go
@@ -0,0 +1,61 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth_test
+
+import (
+	"strings"
+	"testing"
+
+	auth_model "code.gitea.io/gitea/models/auth"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/modules/json"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"xorm.io/xorm/schemas"
+)
+
+type TestSource struct {
+	Provider                      string
+	ClientID                      string
+	ClientSecret                  string
+	OpenIDConnectAutoDiscoveryURL string
+	IconURL                       string
+}
+
+// FromDB fills up a LDAPConfig from serialized format.
+func (source *TestSource) FromDB(bs []byte) error {
+	return json.Unmarshal(bs, &source)
+}
+
+// ToDB exports a LDAPConfig to a serialized format.
+func (source *TestSource) ToDB() ([]byte, error) {
+	return json.Marshal(source)
+}
+
+func TestDumpAuthSource(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+
+	authSourceSchema, err := db.TableInfo(new(auth_model.Source))
+	require.NoError(t, err)
+
+	auth_model.RegisterTypeConfig(auth_model.OAuth2, new(TestSource))
+
+	auth_model.CreateSource(db.DefaultContext, &auth_model.Source{
+		Type:     auth_model.OAuth2,
+		Name:     "TestSource",
+		IsActive: false,
+		Cfg: &TestSource{
+			Provider: "ConvertibleSourceName",
+			ClientID: "42",
+		},
+	})
+
+	sb := new(strings.Builder)
+
+	db.DumpTables([]*schemas.Table{authSourceSchema}, sb)
+
+	assert.Contains(t, sb.String(), `"Provider":"ConvertibleSourceName"`)
+}
diff --git a/models/auth/twofactor.go b/models/auth/twofactor.go
new file mode 100644
index 0000000..d0c341a
--- /dev/null
+++ b/models/auth/twofactor.go
@@ -0,0 +1,166 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"context"
+	"crypto/md5"
+	"crypto/sha256"
+	"crypto/subtle"
+	"encoding/base32"
+	"encoding/base64"
+	"encoding/hex"
+	"fmt"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/secret"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/pquerna/otp/totp"
+	"golang.org/x/crypto/pbkdf2"
+)
+
+//
+// Two-factor authentication
+//
+
+// ErrTwoFactorNotEnrolled indicates that a user is not enrolled in two-factor authentication.
+type ErrTwoFactorNotEnrolled struct {
+	UID int64
+}
+
+// IsErrTwoFactorNotEnrolled checks if an error is a ErrTwoFactorNotEnrolled.
+func IsErrTwoFactorNotEnrolled(err error) bool {
+	_, ok := err.(ErrTwoFactorNotEnrolled)
+	return ok
+}
+
+func (err ErrTwoFactorNotEnrolled) Error() string {
+	return fmt.Sprintf("user not enrolled in 2FA [uid: %d]", err.UID)
+}
+
+// Unwrap unwraps this as a ErrNotExist err
+func (err ErrTwoFactorNotEnrolled) Unwrap() error {
+	return util.ErrNotExist
+}
+
+// TwoFactor represents a two-factor authentication token.
+type TwoFactor struct {
+	ID               int64 `xorm:"pk autoincr"`
+	UID              int64 `xorm:"UNIQUE"`
+	Secret           string
+	ScratchSalt      string
+	ScratchHash      string
+	LastUsedPasscode string             `xorm:"VARCHAR(10)"`
+	CreatedUnix      timeutil.TimeStamp `xorm:"INDEX created"`
+	UpdatedUnix      timeutil.TimeStamp `xorm:"INDEX updated"`
+}
+
+func init() {
+	db.RegisterModel(new(TwoFactor))
+}
+
+// GenerateScratchToken recreates the scratch token the user is using.
+func (t *TwoFactor) GenerateScratchToken() (string, error) {
+	tokenBytes, err := util.CryptoRandomBytes(6)
+	if err != nil {
+		return "", err
+	}
+	// these chars are specially chosen, avoid ambiguous chars like `0`, `O`, `1`, `I`.
+	const base32Chars = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789"
+	token := base32.NewEncoding(base32Chars).WithPadding(base32.NoPadding).EncodeToString(tokenBytes)
+	t.ScratchSalt, _ = util.CryptoRandomString(10)
+	t.ScratchHash = HashToken(token, t.ScratchSalt)
+	return token, nil
+}
+
+// HashToken return the hashable salt
+func HashToken(token, salt string) string {
+	tempHash := pbkdf2.Key([]byte(token), []byte(salt), 10000, 50, sha256.New)
+	return hex.EncodeToString(tempHash)
+}
+
+// VerifyScratchToken verifies if the specified scratch token is valid.
+func (t *TwoFactor) VerifyScratchToken(token string) bool {
+	if len(token) == 0 {
+		return false
+	}
+	tempHash := HashToken(token, t.ScratchSalt)
+	return subtle.ConstantTimeCompare([]byte(t.ScratchHash), []byte(tempHash)) == 1
+}
+
+func (t *TwoFactor) getEncryptionKey() []byte {
+	k := md5.Sum([]byte(setting.SecretKey))
+	return k[:]
+}
+
+// SetSecret sets the 2FA secret.
+func (t *TwoFactor) SetSecret(secretString string) error {
+	secretBytes, err := secret.AesEncrypt(t.getEncryptionKey(), []byte(secretString))
+	if err != nil {
+		return err
+	}
+	t.Secret = base64.StdEncoding.EncodeToString(secretBytes)
+	return nil
+}
+
+// ValidateTOTP validates the provided passcode.
+func (t *TwoFactor) ValidateTOTP(passcode string) (bool, error) {
+	decodedStoredSecret, err := base64.StdEncoding.DecodeString(t.Secret)
+	if err != nil {
+		return false, err
+	}
+	secretBytes, err := secret.AesDecrypt(t.getEncryptionKey(), decodedStoredSecret)
+	if err != nil {
+		return false, err
+	}
+	secretStr := string(secretBytes)
+	return totp.Validate(passcode, secretStr), nil
+}
+
+// NewTwoFactor creates a new two-factor authentication token.
+func NewTwoFactor(ctx context.Context, t *TwoFactor) error {
+	_, err := db.GetEngine(ctx).Insert(t)
+	return err
+}
+
+// UpdateTwoFactor updates a two-factor authentication token.
+func UpdateTwoFactor(ctx context.Context, t *TwoFactor) error {
+	_, err := db.GetEngine(ctx).ID(t.ID).AllCols().Update(t)
+	return err
+}
+
+// GetTwoFactorByUID returns the two-factor authentication token associated with
+// the user, if any.
+func GetTwoFactorByUID(ctx context.Context, uid int64) (*TwoFactor, error) {
+	twofa := &TwoFactor{}
+	has, err := db.GetEngine(ctx).Where("uid=?", uid).Get(twofa)
+	if err != nil {
+		return nil, err
+	} else if !has {
+		return nil, ErrTwoFactorNotEnrolled{uid}
+	}
+	return twofa, nil
+}
+
+// HasTwoFactorByUID returns the two-factor authentication token associated with
+// the user, if any.
+func HasTwoFactorByUID(ctx context.Context, uid int64) (bool, error) {
+	return db.GetEngine(ctx).Where("uid=?", uid).Exist(&TwoFactor{})
+}
+
+// DeleteTwoFactorByID deletes two-factor authentication token by given ID.
+func DeleteTwoFactorByID(ctx context.Context, id, userID int64) error {
+	cnt, err := db.GetEngine(ctx).ID(id).Delete(&TwoFactor{
+		UID: userID,
+	})
+	if err != nil {
+		return err
+	} else if cnt != 1 {
+		return ErrTwoFactorNotEnrolled{userID}
+	}
+	return nil
+}
diff --git a/models/auth/webauthn.go b/models/auth/webauthn.go
new file mode 100644
index 0000000..aa13cf6
--- /dev/null
+++ b/models/auth/webauthn.go
@@ -0,0 +1,209 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/go-webauthn/webauthn/webauthn"
+)
+
+// ErrWebAuthnCredentialNotExist represents a "ErrWebAuthnCRedentialNotExist" kind of error.
+type ErrWebAuthnCredentialNotExist struct {
+	ID           int64
+	CredentialID []byte
+}
+
+func (err ErrWebAuthnCredentialNotExist) Error() string {
+	if len(err.CredentialID) == 0 {
+		return fmt.Sprintf("WebAuthn credential does not exist [id: %d]", err.ID)
+	}
+	return fmt.Sprintf("WebAuthn credential does not exist [credential_id: %x]", err.CredentialID)
+}
+
+// Unwrap unwraps this as a ErrNotExist err
+func (err ErrWebAuthnCredentialNotExist) Unwrap() error {
+	return util.ErrNotExist
+}
+
+// IsErrWebAuthnCredentialNotExist checks if an error is a ErrWebAuthnCredentialNotExist.
+func IsErrWebAuthnCredentialNotExist(err error) bool {
+	_, ok := err.(ErrWebAuthnCredentialNotExist)
+	return ok
+}
+
+// WebAuthnCredential represents the WebAuthn credential data for a public-key
+// credential conformant to WebAuthn Level 3
+type WebAuthnCredential struct {
+	ID              int64 `xorm:"pk autoincr"`
+	Name            string
+	LowerName       string `xorm:"unique(s)"`
+	UserID          int64  `xorm:"INDEX unique(s)"`
+	CredentialID    []byte `xorm:"INDEX VARBINARY(1024)"`
+	PublicKey       []byte
+	AttestationType string
+	AAGUID          []byte
+	SignCount       uint32 `xorm:"BIGINT"`
+	CloneWarning    bool
+	BackupEligible  bool `XORM:"NOT NULL DEFAULT false"`
+	BackupState     bool `XORM:"NOT NULL DEFAULT false"`
+	// If legacy is set to true, backup_eligible and backup_state isn't set.
+	Legacy      bool               `XORM:"NOT NULL DEFAULT true"`
+	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
+	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
+}
+
+func init() {
+	db.RegisterModel(new(WebAuthnCredential))
+}
+
+// TableName returns a better table name for WebAuthnCredential
+func (cred WebAuthnCredential) TableName() string {
+	return "webauthn_credential"
+}
+
+// UpdateSignCount will update the database value of SignCount
+func (cred *WebAuthnCredential) UpdateSignCount(ctx context.Context) error {
+	_, err := db.GetEngine(ctx).ID(cred.ID).Cols("sign_count").Update(cred)
+	return err
+}
+
+// UpdateFromLegacy update the values that aren't present on legacy credentials.
+func (cred *WebAuthnCredential) UpdateFromLegacy(ctx context.Context) error {
+	_, err := db.GetEngine(ctx).ID(cred.ID).Cols("legacy", "backup_eligible", "backup_state").Update(cred)
+	return err
+}
+
+// BeforeInsert will be invoked by XORM before updating a record
+func (cred *WebAuthnCredential) BeforeInsert() {
+	cred.LowerName = strings.ToLower(cred.Name)
+}
+
+// BeforeUpdate will be invoked by XORM before updating a record
+func (cred *WebAuthnCredential) BeforeUpdate() {
+	cred.LowerName = strings.ToLower(cred.Name)
+}
+
+// AfterLoad is invoked from XORM after setting the values of all fields of this object.
+func (cred *WebAuthnCredential) AfterLoad() {
+	cred.LowerName = strings.ToLower(cred.Name)
+}
+
+// WebAuthnCredentialList is a list of *WebAuthnCredential
+type WebAuthnCredentialList []*WebAuthnCredential
+
+// ToCredentials will convert all WebAuthnCredentials to webauthn.Credentials
+func (list WebAuthnCredentialList) ToCredentials() []webauthn.Credential {
+	creds := make([]webauthn.Credential, 0, len(list))
+	for _, cred := range list {
+		creds = append(creds, webauthn.Credential{
+			ID:              cred.CredentialID,
+			PublicKey:       cred.PublicKey,
+			AttestationType: cred.AttestationType,
+			Flags: webauthn.CredentialFlags{
+				BackupEligible: cred.BackupEligible,
+				BackupState:    cred.BackupState,
+			},
+			Authenticator: webauthn.Authenticator{
+				AAGUID:       cred.AAGUID,
+				SignCount:    cred.SignCount,
+				CloneWarning: cred.CloneWarning,
+			},
+		})
+	}
+	return creds
+}
+
+// GetWebAuthnCredentialsByUID returns all WebAuthn credentials of the given user
+func GetWebAuthnCredentialsByUID(ctx context.Context, uid int64) (WebAuthnCredentialList, error) {
+	creds := make(WebAuthnCredentialList, 0)
+	return creds, db.GetEngine(ctx).Where("user_id = ?", uid).Find(&creds)
+}
+
+// ExistsWebAuthnCredentialsForUID returns if the given user has credentials
+func ExistsWebAuthnCredentialsForUID(ctx context.Context, uid int64) (bool, error) {
+	return db.GetEngine(ctx).Where("user_id = ?", uid).Exist(&WebAuthnCredential{})
+}
+
+// GetWebAuthnCredentialByName returns WebAuthn credential by id
+func GetWebAuthnCredentialByName(ctx context.Context, uid int64, name string) (*WebAuthnCredential, error) {
+	cred := new(WebAuthnCredential)
+	if found, err := db.GetEngine(ctx).Where("user_id = ? AND lower_name = ?", uid, strings.ToLower(name)).Get(cred); err != nil {
+		return nil, err
+	} else if !found {
+		return nil, ErrWebAuthnCredentialNotExist{}
+	}
+	return cred, nil
+}
+
+// GetWebAuthnCredentialByID returns WebAuthn credential by id
+func GetWebAuthnCredentialByID(ctx context.Context, id int64) (*WebAuthnCredential, error) {
+	cred := new(WebAuthnCredential)
+	if found, err := db.GetEngine(ctx).ID(id).Get(cred); err != nil {
+		return nil, err
+	} else if !found {
+		return nil, ErrWebAuthnCredentialNotExist{ID: id}
+	}
+	return cred, nil
+}
+
+// HasWebAuthnRegistrationsByUID returns whether a given user has WebAuthn registrations
+func HasWebAuthnRegistrationsByUID(ctx context.Context, uid int64) (bool, error) {
+	return db.GetEngine(ctx).Where("user_id = ?", uid).Exist(&WebAuthnCredential{})
+}
+
+// GetWebAuthnCredentialByCredID returns WebAuthn credential by credential ID
+func GetWebAuthnCredentialByCredID(ctx context.Context, userID int64, credID []byte) (*WebAuthnCredential, error) {
+	cred := new(WebAuthnCredential)
+	if found, err := db.GetEngine(ctx).Where("user_id = ? AND credential_id = ?", userID, credID).Get(cred); err != nil {
+		return nil, err
+	} else if !found {
+		return nil, ErrWebAuthnCredentialNotExist{CredentialID: credID}
+	}
+	return cred, nil
+}
+
+// CreateCredential will create a new WebAuthnCredential from the given Credential
+func CreateCredential(ctx context.Context, userID int64, name string, cred *webauthn.Credential) (*WebAuthnCredential, error) {
+	c := &WebAuthnCredential{
+		UserID:          userID,
+		Name:            name,
+		CredentialID:    cred.ID,
+		PublicKey:       cred.PublicKey,
+		AttestationType: cred.AttestationType,
+		AAGUID:          cred.Authenticator.AAGUID,
+		SignCount:       cred.Authenticator.SignCount,
+		CloneWarning:    false,
+		BackupEligible:  cred.Flags.BackupEligible,
+		BackupState:     cred.Flags.BackupState,
+		Legacy:          false,
+	}
+
+	if err := db.Insert(ctx, c); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+// DeleteCredential will delete WebAuthnCredential
+func DeleteCredential(ctx context.Context, id, userID int64) (bool, error) {
+	had, err := db.GetEngine(ctx).ID(id).Where("user_id = ?", userID).Delete(&WebAuthnCredential{})
+	return had > 0, err
+}
+
+// WebAuthnCredentials implementns the webauthn.User interface
+func WebAuthnCredentials(ctx context.Context, userID int64) ([]webauthn.Credential, error) {
+	dbCreds, err := GetWebAuthnCredentialsByUID(ctx, userID)
+	if err != nil {
+		return nil, err
+	}
+
+	return dbCreds.ToCredentials(), nil
+}
diff --git a/models/auth/webauthn_test.go b/models/auth/webauthn_test.go
new file mode 100644
index 0000000..e1cd652
--- /dev/null
+++ b/models/auth/webauthn_test.go
@@ -0,0 +1,78 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth_test
+
+import (
+	"testing"
+
+	auth_model "code.gitea.io/gitea/models/auth"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+
+	"github.com/go-webauthn/webauthn/webauthn"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetWebAuthnCredentialByID(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+
+	res, err := auth_model.GetWebAuthnCredentialByID(db.DefaultContext, 1)
+	require.NoError(t, err)
+	assert.Equal(t, "WebAuthn credential", res.Name)
+
+	_, err = auth_model.GetWebAuthnCredentialByID(db.DefaultContext, 342432)
+	require.Error(t, err)
+	assert.True(t, auth_model.IsErrWebAuthnCredentialNotExist(err))
+}
+
+func TestGetWebAuthnCredentialsByUID(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+
+	res, err := auth_model.GetWebAuthnCredentialsByUID(db.DefaultContext, 32)
+	require.NoError(t, err)
+	assert.Len(t, res, 1)
+	assert.Equal(t, "WebAuthn credential", res[0].Name)
+}
+
+func TestWebAuthnCredential_TableName(t *testing.T) {
+	assert.Equal(t, "webauthn_credential", auth_model.WebAuthnCredential{}.TableName())
+}
+
+func TestWebAuthnCredential_UpdateSignCount(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	cred := unittest.AssertExistsAndLoadBean(t, &auth_model.WebAuthnCredential{ID: 1})
+	cred.SignCount = 1
+	require.NoError(t, cred.UpdateSignCount(db.DefaultContext))
+	unittest.AssertExistsIf(t, true, &auth_model.WebAuthnCredential{ID: 1, SignCount: 1})
+}
+
+func TestWebAuthnCredential_UpdateLargeCounter(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	cred := unittest.AssertExistsAndLoadBean(t, &auth_model.WebAuthnCredential{ID: 1})
+	cred.SignCount = 0xffffffff
+	require.NoError(t, cred.UpdateSignCount(db.DefaultContext))
+	unittest.AssertExistsIf(t, true, &auth_model.WebAuthnCredential{ID: 1, SignCount: 0xffffffff})
+}
+
+func TestWebAuthenCredential_UpdateFromLegacy(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+	cred := unittest.AssertExistsAndLoadBean(t, &auth_model.WebAuthnCredential{ID: 1, Legacy: true})
+	cred.Legacy = false
+	cred.BackupEligible = true
+	cred.BackupState = true
+	require.NoError(t, cred.UpdateFromLegacy(db.DefaultContext))
+	unittest.AssertExistsIf(t, true, &auth_model.WebAuthnCredential{ID: 1, BackupEligible: true, BackupState: true}, "legacy = false")
+}
+
+func TestCreateCredential(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
+
+	res, err := auth_model.CreateCredential(db.DefaultContext, 1, "WebAuthn Created Credential", &webauthn.Credential{ID: []byte("Test"), Flags: webauthn.CredentialFlags{BackupEligible: true, BackupState: true}})
+	require.NoError(t, err)
+	assert.Equal(t, "WebAuthn Created Credential", res.Name)
+	assert.Equal(t, []byte("Test"), res.CredentialID)
+
+	unittest.AssertExistsIf(t, true, &auth_model.WebAuthnCredential{Name: "WebAuthn Created Credential", UserID: 1, BackupEligible: true, BackupState: true}, "legacy = false")
+}