1 files changed, 180 insertions, 0 deletions
diff --git a/services/auth/basic.go b/services/auth/basic.go
new file mode 100644
index 0000000..d489164
--- /dev/null
+++ b/services/auth/basic.go
@@ -0,0 +1,180 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package auth
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	actions_model "code.gitea.io/gitea/models/actions"
+	auth_model "code.gitea.io/gitea/models/auth"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/util"
+	"code.gitea.io/gitea/modules/web/middleware"
+)
+
+// Ensure the struct implements the interface.
+var (
+	_ Method = &Basic{}
+)
+
+// BasicMethodName is the constant name of the basic authentication method
+const BasicMethodName = "basic"
+
+// Basic implements the Auth interface and authenticates requests (API requests
+// only) by looking for Basic authentication data or "x-oauth-basic" token in the "Authorization"
+// header.
+type Basic struct{}
+
+// Name represents the name of auth method
+func (b *Basic) Name() string {
+	return BasicMethodName
+}
+
+// Verify extracts and validates Basic data (username and password/token) from the
+// "Authorization" header of the request and returns the corresponding user object for that
+// name/token on successful validation.
+// Returns nil if header is empty or validation fails.
+func (b *Basic) Verify(req *http.Request, w http.ResponseWriter, store DataStore, sess SessionStore) (*user_model.User, error) {
+	// Basic authentication should only fire on API, Download or on Git or LFSPaths
+	if !middleware.IsAPIPath(req) && !isContainerPath(req) && !isAttachmentDownload(req) && !isGitRawOrAttachOrLFSPath(req) {
+		return nil, nil
+	}
+
+	baHead := req.Header.Get("Authorization")
+	if len(baHead) == 0 {
+		return nil, nil
+	}
+
+	auths := strings.SplitN(baHead, " ", 2)
+	if len(auths) != 2 || (strings.ToLower(auths[0]) != "basic") {
+		return nil, nil
+	}
+
+	uname, passwd, _ := base.BasicAuthDecode(auths[1])
+
+	// Check if username or password is a token
+	isUsernameToken := len(passwd) == 0 || passwd == "x-oauth-basic"
+	// Assume username is token
+	authToken := uname
+	if !isUsernameToken {
+		log.Trace("Basic Authorization: Attempting login for: %s", uname)
+		// Assume password is token
+		authToken = passwd
+	} else {
+		log.Trace("Basic Authorization: Attempting login with username as token")
+	}
+
+	// check oauth2 token
+	uid, _ := CheckOAuthAccessToken(req.Context(), authToken)
+	if uid != 0 {
+		log.Trace("Basic Authorization: Valid OAuthAccessToken for user[%d]", uid)
+
+		u, err := user_model.GetUserByID(req.Context(), uid)
+		if err != nil {
+			log.Error("GetUserByID:  %v", err)
+			return nil, err
+		}
+
+		store.GetData()["IsApiToken"] = true
+		return u, nil
+	}
+
+	// check personal access token
+	token, err := auth_model.GetAccessTokenBySHA(req.Context(), authToken)
+	if err == nil {
+		log.Trace("Basic Authorization: Valid AccessToken for user[%d]", uid)
+		u, err := user_model.GetUserByID(req.Context(), token.UID)
+		if err != nil {
+			log.Error("GetUserByID:  %v", err)
+			return nil, err
+		}
+
+		token.UpdatedUnix = timeutil.TimeStampNow()
+		if err = auth_model.UpdateAccessToken(req.Context(), token); err != nil {
+			log.Error("UpdateAccessToken:  %v", err)
+		}
+
+		store.GetData()["IsApiToken"] = true
+		store.GetData()["ApiTokenScope"] = token.Scope
+		return u, nil
+	} else if !auth_model.IsErrAccessTokenNotExist(err) && !auth_model.IsErrAccessTokenEmpty(err) {
+		log.Error("GetAccessTokenBySha: %v", err)
+	}
+
+	// check task token
+	task, err := actions_model.GetRunningTaskByToken(req.Context(), authToken)
+	if err == nil && task != nil {
+		log.Trace("Basic Authorization: Valid AccessToken for task[%d]", task.ID)
+
+		store.GetData()["IsActionsToken"] = true
+		store.GetData()["ActionsTaskID"] = task.ID
+
+		return user_model.NewActionsUser(), nil
+	}
+
+	if !setting.Service.EnableBasicAuth {
+		return nil, nil
+	}
+
+	log.Trace("Basic Authorization: Attempting SignIn for %s", uname)
+	u, source, err := UserSignIn(req.Context(), uname, passwd)
+	if err != nil {
+		if !user_model.IsErrUserNotExist(err) {
+			log.Error("UserSignIn: %v", err)
+		}
+		return nil, err
+	}
+
+	hashWebAuthn, err := auth_model.HasWebAuthnRegistrationsByUID(req.Context(), u.ID)
+	if err != nil {
+		log.Error("HasWebAuthnRegistrationsByUID: %v", err)
+		return nil, err
+	}
+
+	if hashWebAuthn {
+		return nil, errors.New("Basic authorization is not allowed while having security keys enrolled")
+	}
+
+	if skipper, ok := source.Cfg.(LocalTwoFASkipper); !ok || !skipper.IsSkipLocalTwoFA() {
+		if err := validateTOTP(req, u); err != nil {
+			return nil, err
+		}
+	}
+
+	log.Trace("Basic Authorization: Logged in user %-v", u)
+
+	return u, nil
+}
+
+func getOtpHeader(header http.Header) string {
+	otpHeader := header.Get("X-Gitea-OTP")
+	if forgejoHeader := header.Get("X-Forgejo-OTP"); forgejoHeader != "" {
+		otpHeader = forgejoHeader
+	}
+	return otpHeader
+}
+
+func validateTOTP(req *http.Request, u *user_model.User) error {
+	twofa, err := auth_model.GetTwoFactorByUID(req.Context(), u.ID)
+	if err != nil {
+		if auth_model.IsErrTwoFactorNotEnrolled(err) {
+			// No 2FA enrollment for this user
+			return nil
+		}
+		return err
+	}
+	if ok, err := twofa.ValidateTOTP(getOtpHeader(req.Header)); err != nil {
+		return err
+	} else if !ok {
+		return util.NewInvalidArgumentErrorf("invalid provided OTP")
+	}
+	return nil
+}