MFA fix, added IP blacklist, update webmail client

internal/smtpserver/auth.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/emersion/go-sasl"
 	"github.com/emersion/go-smtp"
+	"mailgoserver/internal/abuseguard"
 	"mailgoserver/internal/db"
 )
 
@@ -76,6 +77,7 @@ func (s *Session) authenticate(username, password string) error {
 	if err != nil {
 		s.backend.Logger.Error("Authentication error: %v", err)
 		_ = s.backend.DB.LogAuthAttempt("sender", username, s.peerIP, false, fmt.Sprintf("Authentication error: %v", err))
+		abuseguard.RecordFailureAndMaybeBlacklist(s.backend.DB, s.backend.Cfg, s.backend.Logger, s.peerIP)
 		return s.failAuth(451, "Internal server error")
 	}
 	if sender != nil && db.CheckPassword(password, sender.PasswordHash) {
@@ -91,6 +93,7 @@ func (s *Session) authenticate(username, password string) error {
 		if merr != nil {
 			s.backend.Logger.Error("Mailbox authentication error: %v", merr)
 			_ = s.backend.DB.LogAuthAttempt("mailbox", username, s.peerIP, false, fmt.Sprintf("Authentication error: %v", merr))
+			abuseguard.RecordFailureAndMaybeBlacklist(s.backend.DB, s.backend.Cfg, s.backend.Logger, s.peerIP)
 			return s.failAuth(451, "Internal server error")
 		}
 		if mbox != nil {
@@ -103,6 +106,7 @@ func (s *Session) authenticate(username, password string) error {
 	}
 
 	_ = s.backend.DB.LogAuthAttempt("sender", username, s.peerIP, false, fmt.Sprintf("Invalid credentials for %s", username))
+	abuseguard.RecordFailureAndMaybeBlacklist(s.backend.DB, s.backend.Cfg, s.backend.Logger, s.peerIP)
 	return s.failAuth(535, "Authentication failed")
 }