fix(GODT-2617): Validate user can send from the SMTP sender address

https://github.com/ProtonMail/go-proton-api/pull/126

internal/services/smtp/errors.go

@@ -17,9 +17,24 @@
 
 package smtp
 
-import "errors"
+import (
+	"errors"
+	"fmt"
+)
 
 var ErrInvalidRecipient = errors.New("invalid recipient")
 var ErrInvalidReturnPath = errors.New("invalid return path")
 var ErrNoSuchUser = errors.New("no such user")
 var ErrTooManyErrors = errors.New("too many failed requests, please try again later")
+
+type ErrCanNotSendOnAddress struct {
+	address string
+}
+
+func NewErrCanNotSendOnAddress(address string) *ErrCanNotSendOnAddress {
+	return &ErrCanNotSendOnAddress{address: address}
+}
+
+func (e ErrCanNotSendOnAddress) Error() string {
+	return fmt.Sprintf("can't send on address: %v", e.address)
+}

internal/services/smtp/smtp.go

@@ -97,11 +97,16 @@ func (s *Service) smtpSendMail(ctx context.Context, authID string, from string,
 		from = sender
 		fromAddr, err = s.identityState.GetAddr(from)
 		if err != nil {
-			logrus.WithError(err).Errorf("Failed to get identity from sender address %v", sender)
+			logrus.WithError(err).Errorf("Failed to get identity for from address %v", sender)
 			return ErrInvalidReturnPath
 		}
 	}
 
+	if !fromAddr.Send {
+		s.log.Errorf("Can't send emails on address: %v", fromAddr.Email)
+		return &ErrCanNotSendOnAddress{address: fromAddr.Email}
+	}
+
 	// Load the user's mail settings.
 	settings, err := s.client.GetMailSettings(ctx)
 	if err != nil {