Merge branch 'security' into 'main'

Security

See merge request etke.cc/postmoogle!34

.golangci.yml

@@ -1,6 +1,6 @@
 run:
   concurrency: 4
-  timeout: 5m
+  timeout: 30m
   issues-exit-code: 1
   tests: true
   build-tags: []

README.md

@@ -246,6 +246,7 @@ If you want to change them - check available options in the help message (`!pm h
 ---
 
 * **!pm nosender** - Get or set `nosender` of the room (`true` - hide email sender; `false` - show email sender)
+* **!pm norecipient** - Get or set `norecipient` of the room (`true` - hide recipient; `false` - show recipient)
 * **!pm nosubject** - Get or set `nosubject` of the room (`true` - hide email subject; `false` - show email subject)
 * **!pm nohtml** - Get or set `nohtml` of the room (`true` - ignore HTML in email; `false` - parse HTML in emails)
 * **!pm nothreads** - Get or set `nothreads` of the room (`true` - ignore email threads; `false` - convert email threads into matrix threads)
@@ -253,6 +254,14 @@ If you want to change them - check available options in the help message (`!pm h
 
 ---
 
+* **!pm spamcheck:mx** - only accept email from servers which seem prepared to receive it (those having valid MX records) (`true` - enable, `false` - disable)
+* **!pm spamcheck:smtp** - only accept email from servers which seem prepared to receive it (those listening on an SMTP port) (`true` - enable, `false` - disable)
+* **!pm spamlist:emails** - Get or set `spamlist:emails` of the room (comma-separated list), eg: `spammer@example.com,sspam@example.org`
+* **!pm spamlist:hosts** - Get or set `spamlist:hosts` of the room (comma-separated list), eg: `spammer.com,scammer.com,morespam.com`
+* **!pm spamlist:mailboxes** - Get or set `spamlist:mailboxes` of the room (comma-separated list), eg: `notspam,noreply,no-reply`
+
+---
+
 * **!pm dkim** - Get DKIM signature
 * **!pm catch-all** - Configure catch-all mailbox
 * **!pm users** - Get or set allowed users patterns

bot/access.go

@@ -5,6 +5,7 @@ import (
 	"regexp"
 	"strings"
 
+	"github.com/getsentry/sentry-go"
 	"github.com/raja/argon2pw"
 	"gitlab.com/etke.cc/go/mxidwc"
 	"maunium.net/go/mautrix/id"
@@ -40,7 +41,7 @@ func (b *Bot) allowOwner(actorID id.UserID, targetRoomID id.RoomID) bool {
 	}
 	cfg, err := b.getRoomSettings(targetRoomID)
 	if err != nil {
-		b.Error(context.Background(), targetRoomID, "failed to retrieve settings: %v", err)
+		b.Error(sentry.SetHubOnContext(context.Background(), sentry.CurrentHub()), targetRoomID, "failed to retrieve settings: %v", err)
 		return false
 	}
 
@@ -63,7 +64,7 @@ func (b *Bot) allowSend(actorID id.UserID, targetRoomID id.RoomID) bool {
 
 	cfg, err := b.getRoomSettings(targetRoomID)
 	if err != nil {
-		b.Error(context.Background(), targetRoomID, "failed to retrieve settings: %v", err)
+		b.Error(sentry.SetHubOnContext(context.Background(), sentry.CurrentHub()), targetRoomID, "failed to retrieve settings: %v", err)
 		return false
 	}
 

bot/bot.go

@@ -73,7 +73,9 @@ func (b *Bot) Error(ctx context.Context, roomID id.RoomID, message string, args
 	b.log.Error(message, args...)
 	err := fmt.Errorf(message, args...)
 
-	sentry.GetHubFromContext(ctx).CaptureException(err)
+	if hub := sentry.GetHubFromContext(ctx); hub != nil {
+		sentry.GetHubFromContext(ctx).CaptureException(err)
+	}
 	if roomID != "" {
 		b.SendError(ctx, roomID, err.Error())
 	}

bot/command.go

@@ -98,6 +98,15 @@ func (b *Bot) initCommands() commandList {
 			sanitizer: utils.SanitizeBoolString,
 			allowed:   b.allowOwner,
 		},
+		{
+			key: roomOptionNoRecipient,
+			description: fmt.Sprintf(
+				"Get or set `%s` of the room (`true` - hide recipient; `false` - show recipient)",
+				roomOptionNoRecipient,
+			),
+			sanitizer: utils.SanitizeBoolString,
+			allowed:   b.allowOwner,
+		},
 		{
 			key: roomOptionNoSubject,
 			description: fmt.Sprintf(
@@ -134,6 +143,46 @@ func (b *Bot) initCommands() commandList {
 			sanitizer: utils.SanitizeBoolString,
 			allowed:   b.allowOwner,
 		},
+		{allowed: b.allowOwner}, // delimiter
+		{
+			key:         roomOptionSpamcheckMX,
+			description: "only accept email from servers which seem prepared to receive it (those having valid MX records) (`true` - enable, `false` - disable)",
+			sanitizer:   utils.SanitizeBoolString,
+			allowed:     b.allowOwner,
+		},
+		{
+			key:         roomOptionSpamcheckSMTP,
+			description: "only accept email from servers which seem prepared to receive it (those listening on an SMTP port) (`true` - enable, `false` - disable)",
+			sanitizer:   utils.SanitizeBoolString,
+			allowed:     b.allowOwner,
+		},
+		{
+			key: roomOptionSpamlistEmails,
+			description: fmt.Sprintf(
+				"Get or set `%s` of the room (comma-separated list), eg: `spammer@example.com,sspam@example.org`",
+				roomOptionSpamlistEmails,
+			),
+			sanitizer: utils.SanitizeStringSlice,
+			allowed:   b.allowOwner,
+		},
+		{
+			key: roomOptionSpamlistHosts,
+			description: fmt.Sprintf(
+				"Get or set `%s` of the room (comma-separated list), eg: `spammer.com,scammer.com,morespam.com`",
+				roomOptionSpamlistHosts,
+			),
+			sanitizer: utils.SanitizeStringSlice,
+			allowed:   b.allowOwner,
+		},
+		{
+			key: roomOptionSpamlistLocalparts,
+			description: fmt.Sprintf(
+				"Get or set `%s` of the room (comma-separated list), eg: `notspam,noreply,no-reply`",
+				roomOptionSpamlistLocalparts,
+			),
+			sanitizer: utils.SanitizeStringSlice,
+			allowed:   b.allowOwner,
+		},
 		{allowed: b.allowAdmin}, // delimiter
 		{
 			key:         botOptionUsers,

bot/email.go

@@ -59,6 +59,17 @@ func (b *Bot) GetMapping(mailbox string) (id.RoomID, bool) {
 	return roomID, ok
 }
 
+// GetIFOptions returns incoming email filtering options (room settings)
+func (b *Bot) GetIFOptions(roomID id.RoomID) utils.IncomingFilteringOptions {
+	cfg, err := b.getRoomSettings(roomID)
+	if err != nil {
+		b.log.Error("cannot retrieve room settings: %v", err)
+		return roomSettings{}
+	}
+
+	return cfg
+}
+
 // Send email to matrix room
 func (b *Bot) Send2Matrix(ctx context.Context, email *utils.Email, incoming bool) error {
 	roomID, ok := b.GetMapping(email.Mailbox(incoming))

bot/settings_bot.go

@@ -78,6 +78,9 @@ func (b *Bot) getBotSettings() botSettings {
 	if err != nil {
 		b.log.Error("cannot get bot settings: %v", utils.UnwrapError(err))
 	}
+	if config == nil {
+		config = map[string]string{}
+	}
 
 	return config
 }

bot/settings_room.go

@@ -13,15 +13,21 @@ const acRoomSettingsKey = "cc.etke.postmoogle.settings"
 
 // option keys
 const (
-	roomOptionOwner     = "owner"
+	roomOptionOwner              = "owner"
-	roomOptionMailbox   = "mailbox"
+	roomOptionMailbox            = "mailbox"
-	roomOptionNoSend    = "nosend"
+	roomOptionNoSend             = "nosend"
-	roomOptionNoSender  = "nosender"
+	roomOptionNoSender           = "nosender"
-	roomOptionNoSubject = "nosubject"
+	roomOptionNoRecipient        = "norecipient"
-	roomOptionNoHTML    = "nohtml"
+	roomOptionNoSubject          = "nosubject"
-	roomOptionNoThreads = "nothreads"
+	roomOptionNoHTML             = "nohtml"
-	roomOptionNoFiles   = "nofiles"
+	roomOptionNoThreads          = "nothreads"
-	roomOptionPassword  = "password"
+	roomOptionNoFiles            = "nofiles"
+	roomOptionPassword           = "password"
+	roomOptionSpamcheckSMTP      = "spamcheck:smtp"
+	roomOptionSpamcheckMX        = "spamcheck:mx"
+	roomOptionSpamlistEmails     = "spamlist:emails"
+	roomOptionSpamlistHosts      = "spamlist:hosts"
+	roomOptionSpamlistLocalparts = "spamlist:mailboxes"
 )
 
 type roomSettings map[string]string
@@ -56,6 +62,10 @@ func (s roomSettings) NoSender() bool {
 	return utils.Bool(s.Get(roomOptionNoSender))
 }
 
+func (s roomSettings) NoRecipient() bool {
+	return utils.Bool(s.Get(roomOptionNoRecipient))
+}
+
 func (s roomSettings) NoSubject() bool {
 	return utils.Bool(s.Get(roomOptionNoSubject))
 }
@@ -72,13 +82,34 @@ func (s roomSettings) NoFiles() bool {
 	return utils.Bool(s.Get(roomOptionNoFiles))
 }
 
+func (s roomSettings) SpamcheckSMTP() bool {
+	return utils.Bool(s.Get(roomOptionSpamcheckSMTP))
+}
+
+func (s roomSettings) SpamcheckMX() bool {
+	return utils.Bool(s.Get(roomOptionSpamcheckMX))
+}
+
+func (s roomSettings) SpamlistEmails() []string {
+	return utils.StringSlice(s.Get(roomOptionSpamlistEmails))
+}
+
+func (s roomSettings) SpamlistHosts() []string {
+	return utils.StringSlice(s.Get(roomOptionSpamlistHosts))
+}
+
+func (s roomSettings) SpamlistLocalparts() []string {
+	return utils.StringSlice(s.Get(roomOptionSpamlistLocalparts))
+}
+
 // ContentOptions converts room display settings to content options
 func (s roomSettings) ContentOptions() *utils.ContentOptions {
 	return &utils.ContentOptions{
-		HTML:    !s.NoHTML(),
+		HTML:      !s.NoHTML(),
-		Sender:  !s.NoSender(),
+		Sender:    !s.NoSender(),
-		Subject: !s.NoSubject(),
+		Recipient: !s.NoRecipient(),
-		Threads: !s.NoThreads(),
+		Subject:   !s.NoSubject(),
+		Threads:   !s.NoThreads(),
 
 		FromKey:      eventFromKey,
 		SubjectKey:   eventSubjectKey,
@@ -89,6 +120,10 @@ func (s roomSettings) ContentOptions() *utils.ContentOptions {
 
 func (b *Bot) getRoomSettings(roomID id.RoomID) (roomSettings, error) {
 	config, err := b.lp.GetRoomAccountData(roomID, acRoomSettingsKey)
+	if config == nil {
+		config = map[string]string{}
+	}
+
 	return config, utils.UnwrapError(err)
 }
 

go.mod

@@ -19,8 +19,9 @@ require (
 	gitlab.com/etke.cc/go/mxidwc v1.0.0
 	gitlab.com/etke.cc/go/secgen v1.1.1
 	gitlab.com/etke.cc/go/trysmtp v1.0.0
-	gitlab.com/etke.cc/linkpearl v0.0.0-20221002171411-bb783f7e50f0
+	gitlab.com/etke.cc/go/validator v1.0.1
-	golang.org/x/net v0.0.0-20221002022538-bcab6841153b
+	gitlab.com/etke.cc/linkpearl v0.0.0-20221008191655-865ae3362a01
+	golang.org/x/net v0.0.0-20221004154528-8021a29435af
 	maunium.net/go/mautrix v0.12.1
 )
 
@@ -46,8 +47,8 @@ require (
 	github.com/tidwall/pretty v1.2.1 // indirect
 	github.com/tidwall/sjson v1.2.5 // indirect
 	github.com/yuin/goldmark v1.4.13 // indirect
-	golang.org/x/crypto v0.0.0-20220926161630-eccd6366d1be // indirect
+	golang.org/x/crypto v0.0.0-20221005025214-4161e89ecf1b // indirect
-	golang.org/x/sys v0.0.0-20220928140112-f11e5e49a4ec // indirect
+	golang.org/x/sys v0.0.0-20221006211917-84dc82d7e875 // indirect
 	golang.org/x/text v0.3.7 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	maunium.net/go/maulogger/v2 v2.3.2 // indirect

go.sum

@@ -97,16 +97,18 @@ gitlab.com/etke.cc/go/secgen v1.1.1 h1:RmKOki725HIhWJHzPtAc9X4YvBneczndchpMgoDkE
 gitlab.com/etke.cc/go/secgen v1.1.1/go.mod h1:3pJqRGeWApzx7qXjABqz2o2SMCNpKSZao/gXVdasqE8=
 gitlab.com/etke.cc/go/trysmtp v1.0.0 h1:f/7gSmzohKniVeLSLevI+ZsySYcPUGkT9cRlOTwjOr8=
 gitlab.com/etke.cc/go/trysmtp v1.0.0/go.mod h1:KqRuIB2IPElEEbAxXmFyKtm7S5YiuEb4lxwWthccqyE=
-gitlab.com/etke.cc/linkpearl v0.0.0-20221002171411-bb783f7e50f0 h1:B5YV62XKsLb9sCu9jW4Pnc5HDNRzdR1FswtRBMw1sR0=
+gitlab.com/etke.cc/go/validator v1.0.1 h1:xp1tAzgCu9A1pga8rFUo7hODaEcCR1nkkodw96+dYuA=
-gitlab.com/etke.cc/linkpearl v0.0.0-20221002171411-bb783f7e50f0/go.mod h1:hjn0SVswej+Jo3+MycLm+lTsAVFy047Df+adX6MoXoE=
+gitlab.com/etke.cc/go/validator v1.0.1/go.mod h1:3vdssRG4LwgdTr9IHz9MjGSEO+3/FO9hXPGMuSeweJ8=
+gitlab.com/etke.cc/linkpearl v0.0.0-20221008191655-865ae3362a01 h1:rlcxjSCCG18sbNT2CsCRKjtwQ2UjkuTutkRHSCGhhxs=
+gitlab.com/etke.cc/linkpearl v0.0.0-20221008191655-865ae3362a01/go.mod h1:HkUHUkhbkDueEJVc7h/zBfz2hjhl4xxjQKv9Itrdf9k=
 golang.org/x/crypto v0.0.0-20220518034528-6f7dac969898/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
-golang.org/x/crypto v0.0.0-20220926161630-eccd6366d1be h1:fmw3UbQh+nxngCAHrDCCztao/kbYFnWjoqop8dHx05A=
+golang.org/x/crypto v0.0.0-20221005025214-4161e89ecf1b h1:huxqepDufQpLLIRXiVkTvnxrzJlpwmIWAObmcCcUFr0=
-golang.org/x/crypto v0.0.0-20220926161630-eccd6366d1be/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
+golang.org/x/crypto v0.0.0-20221005025214-4161e89ecf1b/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/net v0.0.0-20210501142056-aec3718b3fa0/go.mod h1:OJAsFXCWl8Ukc7SiCT/9KSuxbyM7479/AVlXFRxuMCk=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20220624214902-1bab6f366d9e/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/net v0.0.0-20221002022538-bcab6841153b h1:6e93nYa3hNqAvLr0pD4PN1fFS+gKzp2zAXqrnTCstqU=
+golang.org/x/net v0.0.0-20221004154528-8021a29435af h1:wv66FM3rLZGPdxpYL+ApnDe2HzHcTFta3z5nsc13wI4=
-golang.org/x/net v0.0.0-20221002022538-bcab6841153b/go.mod h1:YDH+HFinaLZZlnHAfSS6ZXJJ9M9t4Dl22yv3iI2vPwk=
+golang.org/x/net v0.0.0-20221004154528-8021a29435af/go.mod h1:YDH+HFinaLZZlnHAfSS6ZXJJ9M9t4Dl22yv3iI2vPwk=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -114,8 +116,8 @@ golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220928140112-f11e5e49a4ec h1:BkDtF2Ih9xZ7le9ndzTA7KJow28VbQW3odyk/8drmuI=
+golang.org/x/sys v0.0.0-20221006211917-84dc82d7e875 h1:AzgQNqF+FKwyQ5LbVrVqOcuuFB67N47F9+htZYH0wFM=
-golang.org/x/sys v0.0.0-20220928140112-f11e5e49a4ec/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20221006211917-84dc82d7e875/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 h1:JGgROgKl9N8DuW20oFS5gxc+lE67/N3FcwmBPMe7ArY=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=

smtp/msasession.go

@@ -9,6 +9,7 @@ import (
 	"github.com/getsentry/sentry-go"
 	"github.com/jhillyerd/enmime"
 	"gitlab.com/etke.cc/go/logger"
+	"gitlab.com/etke.cc/go/validator"
 
 	"gitlab.com/etke.cc/postmoogle/utils"
 )
@@ -43,6 +44,7 @@ func (s *msasession) Mail(from string, opts smtp.MailOptions) error {
 
 func (s *msasession) Rcpt(to string) error {
 	sentry.GetHubFromContext(s.ctx).Scope().SetTag("to", to)
+	s.to = to
 
 	if s.incoming {
 		if utils.Hostname(to) != s.domain {
@@ -50,14 +52,18 @@ func (s *msasession) Rcpt(to string) error {
 			return smtp.ErrAuthRequired
 		}
 
-		_, ok := s.bot.GetMapping(utils.Mailbox(to))
+		roomID, ok := s.bot.GetMapping(utils.Mailbox(to))
 		if !ok {
 			s.log.Debug("mapping for %s not found", to)
 			return smtp.ErrAuthRequired
 		}
+
+		validations := s.bot.GetIFOptions(roomID)
+		if !s.validate(validations) {
+			return smtp.ErrAuthRequired
+		}
 	}
 
-	s.to = to
 	s.log.Debug("mail to %s", to)
 	return nil
 }
@@ -75,6 +81,21 @@ func (s *msasession) parseAttachments(parts []*enmime.Part) []*utils.File {
 	return files
 }
 
+func (s *msasession) validate(options utils.IncomingFilteringOptions) bool {
+	spam := validator.Spam{
+		Emails:     options.SpamlistEmails(),
+		Hosts:      options.SpamlistHosts(),
+		Localparts: options.SpamlistLocalparts(),
+	}
+	enforce := validator.Enforce{
+		MX:   options.SpamcheckMX(),
+		SMTP: options.SpamcheckMX(),
+	}
+	v := validator.New(spam, enforce, s.to, s.log)
+
+	return v.Email(s.from)
+}
+
 func (s *msasession) Data(r io.Reader) error {
 	parser := enmime.NewParser()
 	eml, err := parser.ReadEnvelope(r)

smtp/mta.go

@@ -16,6 +16,7 @@ import (
 type Bot interface {
 	AllowAuth(string, string) bool
 	GetMapping(string) (id.RoomID, bool)
+	GetIFOptions(id.RoomID) utils.IncomingFilteringOptions
 	Send2Matrix(ctx context.Context, email *utils.Email, incoming bool) error
 	SetMTA(mta utils.MTA)
 }

utils/email.go

@@ -19,6 +19,15 @@ type MTA interface {
 	Send(from, to, data string) error
 }
 
+// IncomingFilteringOptions for incoming mail
+type IncomingFilteringOptions interface {
+	SpamcheckSMTP() bool
+	SpamcheckMX() bool
+	SpamlistEmails() []string
+	SpamlistHosts() []string
+	SpamlistLocalparts() []string
+}
+
 // Email object
 type Email struct {
 	Date      string
@@ -35,10 +44,11 @@ type Email struct {
 // ContentOptions represents settings that specify how an email is to be converted to a Matrix message
 type ContentOptions struct {
 	// On/Off
-	Sender  bool
+	Sender    bool
-	Subject bool
+	Recipient bool
-	HTML    bool
+	Subject   bool
-	Threads bool
+	HTML      bool
+	Threads   bool
 
 	// Keys
 	MessageIDKey string
@@ -92,7 +102,12 @@ func (e *Email) Content(threadID id.EventID, options *ContentOptions) *event.Con
 	if options.Sender {
 		text.WriteString("From: ")
 		text.WriteString(e.From)
-		text.WriteString("\n\n")
+		text.WriteString("\n")
+	}
+	if options.Recipient {
+		text.WriteString("To: ")
+		text.WriteString(e.To)
+		text.WriteString("\n")
 	}
 	if options.Subject {
 		text.WriteString("# ")

utils/utils.go

@@ -33,3 +33,31 @@ func Bool(str string) bool {
 func SanitizeBoolString(str string) string {
 	return strconv.FormatBool(Bool(str))
 }
+
+// StringSlice converts comma-separated string to slice
+func StringSlice(str string) []string {
+	if str == "" {
+		return nil
+	}
+
+	str = strings.TrimSpace(str)
+	if strings.IndexByte(str, ',') == -1 {
+		return []string{str}
+	}
+
+	return strings.Split(str, ",")
+}
+
+// SanitizeBoolString converts string to slice and back to string
+func SanitizeStringSlice(str string) string {
+	parts := StringSlice(str)
+	if len(parts) == 0 {
+		return str
+	}
+
+	for i, part := range parts {
+		parts[i] = strings.TrimSpace(part)
+	}
+
+	return strings.Join(parts, ",")
+}