MM-67108: Auto-generate Encryption Key on upgrade if missing

server/plugin.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"crypto/rand"
+	"encoding/base64"
 	"fmt"
 	"html/template"
 	"net/http"
@@ -101,6 +103,21 @@ func (p *Plugin) OnConfigurationChange() error {
 		return err
 	}
 
+	if len(configuration.EncryptionKey) != 32 {
+		newKey, err := generateRandomKey(32)
+		if err != nil {
+			config.Mattermost.LogError("Error generating encryption key.", "Error", err.Error())
+			return err
+		}
+		configuration.EncryptionKey = newKey
+		config.Mattermost.LogInfo("Auto-generated missing Encryption Key.")
+
+		if err := p.savePluginConfig(&configuration); err != nil {
+			config.Mattermost.LogError("Error saving auto-generated encryption key.", "Error", err.Error())
+			return err
+		}
+	}
+
 	if err := configuration.IsValid(); err != nil {
 		config.Mattermost.LogError("Error in Validating Configuration.", "Error", err.Error())
 		return err
@@ -110,6 +127,29 @@ func (p *Plugin) OnConfigurationChange() error {
 	return nil
 }
 
+func generateRandomKey(length int) (string, error) {
+	// We need more bytes because base64 encoding expands the size
+	bytes := make([]byte, length)
+	if _, err := rand.Read(bytes); err != nil {
+		return "", err
+	}
+	encoded := base64.URLEncoding.EncodeToString(bytes)
+	return encoded[:length], nil
+}
+
+func (p *Plugin) savePluginConfig(configuration *config.Configuration) error {
+	configMap, err := configuration.ToMap()
+	if err != nil {
+		return errors.Wrap(err, "failed to convert config to map")
+	}
+
+	if appErr := p.API.SavePluginConfig(configMap); appErr != nil {
+		return errors.Wrap(appErr, "failed to save plugin config")
+	}
+
+	return nil
+}
+
 func (p *Plugin) setUpBotUser() error {
 	botUserID, err := p.client.Bot.EnsureBot(&model.Bot{
 		Username:    botUserName,

server/plugin_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/mattermost/mattermost/server/public/plugin/plugintest"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
 
 	"github.com/mattermost/mattermost-plugin-confluence/server/config"
 )
@@ -58,3 +59,79 @@ func TestExecuteCommand(t *testing.T) {
 		})
 	}
 }
+
+func TestGenerateRandomKey(t *testing.T) {
+	t.Run("generates key of correct length", func(t *testing.T) {
+		key, err := generateRandomKey(32)
+		require.NoError(t, err)
+		assert.Len(t, key, 32)
+	})
+
+	t.Run("generates unique keys", func(t *testing.T) {
+		key1, err := generateRandomKey(32)
+		require.NoError(t, err)
+
+		key2, err := generateRandomKey(32)
+		require.NoError(t, err)
+
+		assert.NotEqual(t, key1, key2, "Generated keys should be unique")
+	})
+
+	t.Run("generates different lengths", func(t *testing.T) {
+		key16, err := generateRandomKey(16)
+		require.NoError(t, err)
+		assert.Len(t, key16, 16)
+
+		key64, err := generateRandomKey(64)
+		require.NoError(t, err)
+		assert.Len(t, key64, 64)
+	})
+}
+
+func TestOnConfigurationChange_AutoGenerateEncryptionKey(t *testing.T) {
+	t.Run("auto-generates encryption key when missing", func(t *testing.T) {
+		mockAPI := &plugintest.API{}
+		config.Mattermost = mockAPI
+
+		p := &Plugin{}
+		p.SetAPI(mockAPI)
+
+		// Configuration with valid secret but missing encryption key
+		mockAPI.On("LoadPluginConfiguration", mock.AnythingOfType("*config.Configuration")).Run(func(args mock.Arguments) {
+			cfg := args.Get(0).(*config.Configuration)
+			cfg.Secret = "12345678901234567890123456789012" // 32 chars
+			cfg.EncryptionKey = ""                          // Empty - should be auto-generated
+		}).Return(nil)
+
+		mockAPI.On("LogInfo", "Auto-generated missing Encryption Key.").Return()
+		mockAPI.On("SavePluginConfig", mock.AnythingOfType("map[string]interface {}")).Return(nil)
+
+		err := p.OnConfigurationChange()
+		require.NoError(t, err)
+
+		// Verify SavePluginConfig was called (meaning key was generated and saved)
+		mockAPI.AssertCalled(t, "SavePluginConfig", mock.AnythingOfType("map[string]interface {}"))
+	})
+
+	t.Run("does not overwrite existing valid encryption key", func(t *testing.T) {
+		mockAPI := &plugintest.API{}
+		config.Mattermost = mockAPI
+
+		p := &Plugin{}
+		p.SetAPI(mockAPI)
+
+		existingKey := "abcdefghijklmnopqrstuvwxyz123456" // 32 chars
+
+		mockAPI.On("LoadPluginConfiguration", mock.AnythingOfType("*config.Configuration")).Run(func(args mock.Arguments) {
+			cfg := args.Get(0).(*config.Configuration)
+			cfg.Secret = "12345678901234567890123456789012"
+			cfg.EncryptionKey = existingKey
+		}).Return(nil)
+
+		err := p.OnConfigurationChange()
+		require.NoError(t, err)
+
+		// SavePluginConfig should NOT be called since key is valid
+		mockAPI.AssertNotCalled(t, "SavePluginConfig", mock.Anything)
+	})
+}