Horde_Imap_Client_Socket::_tryLogin PHP Method

    protected function _tryLogin($method)
    {
        $username = $this->getParam('username');
        $password = $this->getParam('password');
        switch ($method) {
            case 'CRAM-MD5':
            case 'CRAM-SHA1':
            case 'CRAM-SHA256':
                // RFC 2195: CRAM-MD5
                // CRAM-SHA1 & CRAM-SHA256 supported by Courier SASL library
                $args = array($username, Horde_String::lower(substr($method, 5)), $password);
                $cmd = $this->_command('AUTHENTICATE')->add(array($method, new Horde_Imap_Client_Interaction_Command_Continuation(function ($ob) use($args) {
                    return new Horde_Imap_Client_Data_Format_List(base64_encode($args[0] . ' ' . hash_hmac($args[1], base64_decode($ob->token->current()), $args[2], false)));
                })));
                $cmd->debug = array(null, sprintf('[AUTHENTICATE response (username: %s)]', $username));
                break;
            case 'DIGEST-MD5':
                // RFC 2831/4422; obsoleted by RFC 6331
                // Need $args because PHP 5.3 doesn't allow access to $this in
                // anonymous functions.
                $args = array($username, $password, $this->getParam('hostspec'));
                $cmd = $this->_command('AUTHENTICATE')->add(array($method, new Horde_Imap_Client_Interaction_Command_Continuation(function ($ob) use($args) {
                    return new Horde_Imap_Client_Data_Format_List(base64_encode(new Horde_Imap_Client_Auth_DigestMD5($args[0], $args[1], base64_decode($ob->token->current()), $args[2], 'imap')));
                }), new Horde_Imap_Client_Interaction_Command_Continuation(function ($ob) {
                    if (strpos(base64_decode($ob->token->current()), 'rspauth=') === false) {
                        throw new Horde_Imap_Client_Exception(Horde_Imap_Client_Translation::r("Unexpected response from server when authenticating."), Horde_Imap_Client_Exception::SERVER_CONNECT);
                    }
                    return new Horde_Imap_Client_Data_Format_List();
                })));
                $cmd->debug = array(null, sprintf('[AUTHENTICATE Response (username: %s)]', $username), null);
                break;
            case 'LOGIN':
                /* See, e.g., RFC 6855 [5] - LOGIN command does not support
                 * non-ASCII characters. If we reach this point, treat as an
                 * authentication failure. */
                try {
                    $username = new Horde_Imap_Client_Data_Format_Astring($username);
                    $password = new Horde_Imap_Client_Data_Format_Astring($password);
                } catch (Horde_Imap_Client_Data_Format_Exception $e) {
                    throw new Horde_Imap_Client_Exception(Horde_Imap_Client_Translation::r("Authentication failed."), Horde_Imap_Client_Exception::LOGIN_AUTHENTICATIONFAILED);
                }
                $cmd = $this->_command('LOGIN')->add(array($username, $password));
                $cmd->debug = array(sprintf('LOGIN %s [PASSWORD]', $username));
                break;
            case 'PLAIN':
                // RFC 2595/4616 - PLAIN SASL mechanism
                $cmd = $this->_authInitialResponse($method, base64_encode(implode("", array($username, $username, $password))), $username);
                break;
            case 'SCRAM-SHA-1':
                $scram = new Horde_Imap_Client_Auth_Scram($username, $password, 'SHA1');
                $cmd = $this->_authInitialResponse($method, base64_encode($scram->getClientFirstMessage()));
                $cmd->add(new Horde_Imap_Client_Interaction_Command_Continuation(function ($ob) use($scram) {
                    $sr1 = base64_decode($ob->token->current());
                    return new Horde_Imap_Client_Data_Format_List($scram->parseServerFirstMessage($sr1) ? base64_encode($scram->getClientFinalMessage()) : '*');
                }));
                $self = $this;
                $cmd->add(new Horde_Imap_Client_Interaction_Command_Continuation(function ($ob) use($scram, $self) {
                    $sr2 = base64_decode($ob->token->current());
                    if (!$scram->parseServerFinalMessage($sr2)) {
                        /* This means authentication passed, according to the
                         * server, but the server signature is incorrect.
                         * This indicates that server verification has failed.
                         * Immediately disconnect from the server, since this
                         * is a possible security issue. */
                        $self->logout();
                        throw new Horde_Imap_Client_Exception(Horde_Imap_Client_Translation::r("Server failed verification check."), Horde_Imap_Client_Exception::LOGIN_SERVER_VERIFICATION_FAILED);
                    }
                    return new Horde_Imap_Client_Data_Format_List();
                }));
                break;
            case 'XOAUTH2':
                // Google XOAUTH2
                $cmd = $this->_authInitialResponse($method, $this->getParam('xoauth2_token'));
                /* This is an optional command continuation. XOAUTH2 will return
                 * error information in continuation response. */
                $error_continuation = new Horde_Imap_Client_Interaction_Command_Continuation(function ($ob) {
                    return new Horde_Imap_Client_Data_Format_List();
                });
                $error_continuation->optional = true;
                $cmd->add($error_continuation);
                break;
            default:
                $e = new Horde_Imap_Client_Exception(Horde_Imap_Client_Translation::r("Unknown authentication method: %s"), Horde_Imap_Client_Exception::SERVER_CONNECT);
                $e->messagePrintf(array($method));
                throw $e;
        }
        return $this->_sendCmd($this->_pipeline($cmd));
    }