1 files changed, 152 insertions, 0 deletions
diff --git a/routers/api/shared/middleware.go b/routers/api/shared/middleware.go
new file mode 100644
index 0000000..e2ff004
--- /dev/null
+++ b/routers/api/shared/middleware.go
@@ -0,0 +1,152 @@
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package shared
+
+import (
+	"net/http"
+
+	auth_model "code.gitea.io/gitea/models/auth"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/routers/common"
+	"code.gitea.io/gitea/services/auth"
+	"code.gitea.io/gitea/services/context"
+
+	"github.com/go-chi/cors"
+)
+
+func Middlewares() (stack []any) {
+	stack = append(stack, securityHeaders())
+
+	if setting.CORSConfig.Enabled {
+		stack = append(stack, cors.Handler(cors.Options{
+			AllowedOrigins:   setting.CORSConfig.AllowDomain,
+			AllowedMethods:   setting.CORSConfig.Methods,
+			AllowCredentials: setting.CORSConfig.AllowCredentials,
+			AllowedHeaders:   append([]string{"Authorization", "X-Gitea-OTP", "X-Forgejo-OTP"}, setting.CORSConfig.Headers...),
+			MaxAge:           int(setting.CORSConfig.MaxAge.Seconds()),
+		}))
+	}
+	return append(stack,
+		context.APIContexter(),
+
+		checkDeprecatedAuthMethods,
+		// Get user from session if logged in.
+		apiAuth(buildAuthGroup()),
+		verifyAuthWithOptions(&common.VerifyOptions{
+			SignInRequired: setting.Service.RequireSignInView,
+		}),
+	)
+}
+
+func buildAuthGroup() *auth.Group {
+	group := auth.NewGroup(
+		&auth.OAuth2{},
+		&auth.HTTPSign{},
+		&auth.Basic{}, // FIXME: this should be removed once we don't allow basic auth in API
+	)
+	if setting.Service.EnableReverseProxyAuthAPI {
+		group.Add(&auth.ReverseProxy{})
+	}
+
+	if setting.IsWindows && auth_model.IsSSPIEnabled(db.DefaultContext) {
+		group.Add(&auth.SSPI{}) // it MUST be the last, see the comment of SSPI
+	}
+
+	return group
+}
+
+func apiAuth(authMethod auth.Method) func(*context.APIContext) {
+	return func(ctx *context.APIContext) {
+		ar, err := common.AuthShared(ctx.Base, nil, authMethod)
+		if err != nil {
+			ctx.Error(http.StatusUnauthorized, "APIAuth", err)
+			return
+		}
+		ctx.Doer = ar.Doer
+		ctx.IsSigned = ar.Doer != nil
+		ctx.IsBasicAuth = ar.IsBasicAuth
+	}
+}
+
+// verifyAuthWithOptions checks authentication according to options
+func verifyAuthWithOptions(options *common.VerifyOptions) func(ctx *context.APIContext) {
+	return func(ctx *context.APIContext) {
+		// Check prohibit login users.
+		if ctx.IsSigned {
+			if !ctx.Doer.IsActive && setting.Service.RegisterEmailConfirm {
+				ctx.Data["Title"] = ctx.Tr("auth.active_your_account")
+				ctx.JSON(http.StatusForbidden, map[string]string{
+					"message": "This account is not activated.",
+				})
+				return
+			}
+			if !ctx.Doer.IsActive || ctx.Doer.ProhibitLogin {
+				log.Info("Failed authentication attempt for %s from %s", ctx.Doer.Name, ctx.RemoteAddr())
+				ctx.Data["Title"] = ctx.Tr("auth.prohibit_login")
+				ctx.JSON(http.StatusForbidden, map[string]string{
+					"message": "This account is prohibited from signing in, please contact your site administrator.",
+				})
+				return
+			}
+
+			if ctx.Doer.MustChangePassword {
+				ctx.JSON(http.StatusForbidden, map[string]string{
+					"message": "You must change your password. Change it at: " + setting.AppURL + "/user/change_password",
+				})
+				return
+			}
+		}
+
+		// Redirect to dashboard if user tries to visit any non-login page.
+		if options.SignOutRequired && ctx.IsSigned && ctx.Req.URL.RequestURI() != "/" {
+			ctx.Redirect(setting.AppSubURL + "/")
+			return
+		}
+
+		if options.SignInRequired {
+			if !ctx.IsSigned {
+				// Restrict API calls with error message.
+				ctx.JSON(http.StatusForbidden, map[string]string{
+					"message": "Only signed in user is allowed to call APIs.",
+				})
+				return
+			} else if !ctx.Doer.IsActive && setting.Service.RegisterEmailConfirm {
+				ctx.Data["Title"] = ctx.Tr("auth.active_your_account")
+				ctx.JSON(http.StatusForbidden, map[string]string{
+					"message": "This account is not activated.",
+				})
+				return
+			}
+		}
+
+		if options.AdminRequired {
+			if !ctx.Doer.IsAdmin {
+				ctx.JSON(http.StatusForbidden, map[string]string{
+					"message": "You have no permission to request for this.",
+				})
+				return
+			}
+		}
+	}
+}
+
+// check for and warn against deprecated authentication options
+func checkDeprecatedAuthMethods(ctx *context.APIContext) {
+	if ctx.FormString("token") != "" || ctx.FormString("access_token") != "" {
+		ctx.Resp.Header().Set("Warning", "token and access_token API authentication is deprecated and will be removed in gitea 1.23. Please use AuthorizationHeaderToken instead. Existing queries will continue to work but without authorization.")
+	}
+}
+
+func securityHeaders() func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
+			// CORB: https://www.chromium.org/Home/chromium-security/corb-for-developers
+			// http://stackoverflow.com/a/3146618/244009
+			resp.Header().Set("x-content-type-options", "nosniff")
+			next.ServeHTTP(resp, req)
+		})
+	}
+}