snapshot of https://github.com/mattermost/mattermost.git (master, 2026-09-16; blobs > 131072B omitted)

server/channels/app/plugin_file_download_hook_test.go

@@ -0,0 +1,529 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package app
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+
+	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/plugin"
+	"github.com/mattermost/mattermost/server/public/plugin/plugintest"
+)
+
+func TestHookFileWillBeDownloaded(t *testing.T) {
+	mainHelper.Parallel(t)
+
+	t.Run("rejected", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		var mockAPI plugintest.API
+		mockAPI.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		// Allow any logging calls (not verified in this test)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+
+		tearDown, _, _ := SetAppEnvironmentWithPlugins(t, []string{
+			`
+			package main
+
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				p.API.LogInfo("Rejecting file download", "file_id", info.Id, "user_id", userID)
+				return "Download blocked by security policy"
+			}
+
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+		}, th.App, func(*model.Manifest) plugin.API { return &mockAPI })
+		defer tearDown()
+
+		// Upload a file first
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+		require.NotNil(t, fileInfo)
+
+		// Get the file info to pass to the hook
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		// Call the hook through the app method
+		rejectionReason := th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeFile)
+
+		// Verify the file download was rejected
+		assert.NotEmpty(t, rejectionReason)
+		assert.Contains(t, rejectionReason, "blocked by security policy")
+		mockAPI.AssertExpectations(t)
+	})
+
+	t.Run("allowed", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		var mockAPI plugintest.API
+		mockAPI.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		// Allow any logging calls (not verified in this test)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+
+		tearDown, _, _ := SetAppEnvironmentWithPlugins(t, []string{
+			`
+			package main
+
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				p.API.LogInfo("Allowing file download", "file_id", info.Id, "user_id", userID)
+				// Return empty string to allow download
+				return ""
+			}
+
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+		}, th.App, func(*model.Manifest) plugin.API { return &mockAPI })
+		defer tearDown()
+
+		// Upload a file
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+		require.NotNil(t, fileInfo)
+
+		// Get the file info
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		// Call the hook through the app method
+		rejectionReason := th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeFile)
+
+		// Verify the file download was allowed
+		assert.Empty(t, rejectionReason)
+		mockAPI.AssertExpectations(t)
+	})
+
+	t.Run("multiple plugins - first rejects", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		var mockAPI1 plugintest.API
+		mockAPI1.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		// Allow any logging calls (not verified in this test)
+		mockAPI1.On("LogInfo", mock.Anything).Maybe().Return(nil)
+		mockAPI1.On("LogInfo", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI1.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI1.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI1.On("LogWarn", mock.Anything).Maybe().Return(nil)
+		mockAPI1.On("LogWarn", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI1.On("LogWarn", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI1.On("LogWarn", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+
+		var mockAPI2 plugintest.API
+		mockAPI2.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		// This plugin should NOT be called because first one rejects
+
+		tearDown, _, _ := SetAppEnvironmentWithPlugins(t, []string{
+			// First plugin - rejects
+			`
+			package main
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				p.API.LogWarn("First plugin rejecting", "file_id", info.Id)
+				return "Rejected by first plugin"
+			}
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+			// Second plugin - should not be called
+			`
+			package main
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				p.API.LogInfo("Second plugin should not be called")
+				return ""
+			}
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+		}, th.App, func(*model.Manifest) plugin.API {
+			// Alternate between the two mock APIs
+			return &mockAPI1
+		})
+		defer tearDown()
+
+		// Upload a file
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		// Call hooks - first one should reject, second should not be called
+		rejectionReason := th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeFile)
+
+		assert.NotEmpty(t, rejectionReason)
+		assert.Contains(t, rejectionReason, "Rejected by first plugin")
+
+		// Only first mock API should have been called
+		mockAPI1.AssertExpectations(t)
+		// mockAPI2 should not have been called (no expectations set)
+	})
+
+	t.Run("no plugins installed", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		// No plugins - hook should return empty
+
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		rejectionReason := th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeFile)
+
+		// No plugins means no rejection
+		assert.Empty(t, rejectionReason)
+	})
+}
+
+// TestHookFileWillBeDownloadedHeadRequests tests that HEAD requests trigger the FileWillBeDownloaded hook
+func TestHookFileWillBeDownloadedHeadRequests(t *testing.T) {
+	mainHelper.Parallel(t)
+
+	t.Run("HEAD request to file endpoint triggers hook - rejection", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		var mockAPI plugintest.API
+		mockAPI.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+
+		tearDown, _, _ := SetAppEnvironmentWithPlugins(t, []string{
+			`
+			package main
+
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				p.API.LogInfo("Blocking file download", "file_id", info.Id, "download_type", string(downloadType))
+				return "File download blocked by security policy"
+			}
+
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+		}, th.App, func(*model.Manifest) plugin.API { return &mockAPI })
+		defer tearDown()
+
+		// Upload a file first
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+		require.NotNil(t, fileInfo)
+
+		// Get the file info to pass to the hook
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		// Call the hook through the app method
+		rejectionReason := th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeFile)
+
+		// Verify the file download was rejected
+		assert.NotEmpty(t, rejectionReason)
+		assert.Contains(t, rejectionReason, "blocked by security policy")
+		mockAPI.AssertExpectations(t)
+	})
+
+	t.Run("HEAD request to thumbnail endpoint triggers hook - rejection", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		var mockAPI plugintest.API
+		mockAPI.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+
+		tearDown, _, _ := SetAppEnvironmentWithPlugins(t, []string{
+			`
+			package main
+
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				// Only block thumbnail requests
+				if downloadType == model.FileDownloadTypeThumbnail {
+					p.API.LogInfo("Blocking thumbnail download", "file_id", info.Id)
+					return "Thumbnail download blocked"
+				}
+				return ""
+			}
+
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+		}, th.App, func(*model.Manifest) plugin.API { return &mockAPI })
+		defer tearDown()
+
+		// Upload a file
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+		require.NotNil(t, fileInfo)
+
+		// Get the file info
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		// Call the hook for thumbnail download type through the app method
+		rejectionReason := th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeThumbnail)
+
+		// Verify the thumbnail download was rejected
+		assert.NotEmpty(t, rejectionReason)
+		assert.Contains(t, rejectionReason, "Thumbnail download blocked")
+		mockAPI.AssertExpectations(t)
+	})
+
+	t.Run("HEAD request to preview endpoint triggers hook - rejection", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		var mockAPI plugintest.API
+		mockAPI.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogWarn", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+
+		tearDown, _, _ := SetAppEnvironmentWithPlugins(t, []string{
+			`
+			package main
+
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				// Only block preview requests
+				if downloadType == model.FileDownloadTypePreview {
+					p.API.LogInfo("Blocking preview download", "file_id", info.Id)
+					return "Preview download blocked"
+				}
+				return ""
+			}
+
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+		}, th.App, func(*model.Manifest) plugin.API { return &mockAPI })
+		defer tearDown()
+
+		// Upload a file
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+		require.NotNil(t, fileInfo)
+
+		// Get the file info
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		// Create plugin context
+		// Call the hook for preview download type through the app method
+		rejectionReason := th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypePreview)
+
+		// Verify the preview download was rejected
+		assert.NotEmpty(t, rejectionReason)
+		assert.Contains(t, rejectionReason, "Preview download blocked")
+		mockAPI.AssertExpectations(t)
+	})
+
+	t.Run("HEAD request to file endpoint triggers hook - allowed", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		var mockAPI plugintest.API
+		mockAPI.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+
+		tearDown, _, _ := SetAppEnvironmentWithPlugins(t, []string{
+			`
+			package main
+
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				p.API.LogInfo("Allowing file download", "file_id", info.Id, "download_type", string(downloadType))
+				return "" // Allow download
+			}
+
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+		}, th.App, func(*model.Manifest) plugin.API { return &mockAPI })
+		defer tearDown()
+
+		// Upload a file
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+		require.NotNil(t, fileInfo)
+
+		// Get the file info
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		// Call the hook through the app method
+		rejectionReason := th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeFile)
+
+		// Verify the file download was allowed
+		assert.Empty(t, rejectionReason)
+		mockAPI.AssertExpectations(t)
+	})
+
+	t.Run("HEAD and GET with different download types", func(t *testing.T) {
+		mainHelper.Parallel(t)
+		th := Setup(t).InitBasic(t)
+
+		downloadTypesReceived := []model.FileDownloadType{}
+
+		var mockAPI plugintest.API
+		mockAPI.On("LoadPluginConfiguration", mock.Anything).Return(nil).Maybe()
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything).Run(func(args mock.Arguments) {
+			if args.String(0) == "Hook called" {
+				downloadType := args.String(2)
+				downloadTypesReceived = append(downloadTypesReceived, model.FileDownloadType(downloadType))
+			}
+		}).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+		mockAPI.On("LogInfo", mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything, mock.Anything).Maybe().Return(nil)
+
+		tearDown, _, _ := SetAppEnvironmentWithPlugins(t, []string{
+			`
+			package main
+
+			import (
+				"github.com/mattermost/mattermost/server/public/plugin"
+				"github.com/mattermost/mattermost/server/public/model"
+			)
+
+			type MyPlugin struct {
+				plugin.MattermostPlugin
+			}
+
+			func (p *MyPlugin) FileWillBeDownloaded(c *plugin.Context, info *model.FileInfo, userID string, downloadType model.FileDownloadType) string {
+				p.API.LogInfo("Hook called", "download_type", string(downloadType))
+				return "" // Allow download
+			}
+
+			func main() {
+				plugin.ClientMain(&MyPlugin{})
+			}
+			`,
+		}, th.App, func(*model.Manifest) plugin.API { return &mockAPI })
+		defer tearDown()
+
+		// Upload a file
+		fileInfo, appErr := th.App.UploadFile(th.Context, []byte("test content"), th.BasicChannel.Id, "test.txt")
+		require.Nil(t, appErr)
+
+		info, appErr := th.App.GetFileInfo(th.Context, fileInfo.Id)
+		require.Nil(t, appErr)
+
+		// Test File download type
+		th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeFile)
+
+		// Test Thumbnail download type
+		th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypeThumbnail)
+
+		// Test Preview download type
+		th.App.RunFileWillBeDownloadedHook(th.Context, info, th.BasicUser.Id, "", model.FileDownloadTypePreview)
+
+		// Verify all three download types were received
+		assert.Len(t, downloadTypesReceived, 3)
+		assert.Contains(t, downloadTypesReceived, model.FileDownloadTypeFile)
+		assert.Contains(t, downloadTypesReceived, model.FileDownloadTypeThumbnail)
+		assert.Contains(t, downloadTypesReceived, model.FileDownloadTypePreview)
+
+		mockAPI.AssertExpectations(t)
+	})
+}