lib/classes/Swift/Signers/SMimeSigner.php
public function signMessage(Swift_Message $message)
    {
        if (null === $this->signCertificate && null === $this->encryptCert) {
            return $this;
        }

        if ($this->signThenEncrypt) {
            $this->smimeSignMessage($message);
            $this->smimeEncryptMessage($message);
        } else {
            $this->smimeEncryptMessage($message);
            $this->smimeSignMessage($message);
        }
    }
public function signMessage(Swift_Message $message)
    {
        if (null === $this->signCertificate && null === $this->encryptCert) {
            return $this;
        }

        if ($this->signThenEncrypt) {
            $this->smimeSignMessage($message);
            $this->smimeEncryptMessage($message);
        } else {
            $this->smimeEncryptMessage($message);
            $this->smimeSignMessage($message);
        }
    }
public function signMessage ( Swift_Message $ message ) { if ( null === $ this -> signCertificate && null === $ this -> encryptCert ) { return $ this ; } if ( $ this -> signThenEncrypt ) { $ this -> smimeSignMessage ( $ message ) ; $ this -> smimeEncryptMessage ( $ message ) ; } else { $ this -> smimeEncryptMessage ( $ message ) ; $ this -> smimeSignMessage ( $ message ) ; } }
Change the Swift_Message to apply the signing.

@return $this
Change the Swift_Message to apply the signing .