He estado tratando de pasar a un FTP remoto con un servidor TLS / SSL explícito y la conexión se agota. Se está conectando pero no sé dónde se está deteniendo, pero supongo que es algo que tiene que ver con el canal de control FTP / TLS / SSL. Cualquier ayuda sería muy apreciada.

A través de FileZilla puedo conectarme sin problemas pero no a través de curl. Probablemente me estoy perdiendo algo y espero que alguien aquí conozca la mejor manera de recrear la sesión usando curl. Aquí está la salida de depuración de FileZilla y el código de muestra en el que he estado trabajando en PHP / curl. Aquí está el código PHP y debajo hay una copia de una sesión exitosa de FileZilla.

Aquí están las versiones, pero lo he probado en diferentes sistemas con los mismos resultados.

Curl: v7.43.0

└─(08:04:00 on master ✹)──> php -v                                          ──(Thu,Sep10)─┘
PHP 5.5.27 (cli) (built: Jul 14 2015 17:04:01)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2015 Zend Technologies
    with Xdebug v2.3.3, Copyright (c) 2002-2015, by Derick Rethans

Aquí está el código real.

<?php

$server_data = array(
   'transfer_id' => 123456789,
   'post_url' => "ftps://ftps.widgetsltd.com",
   'port' => 21,
   'username' => 'widgetsftp',
   'password' => 'password',
);

$filename = sprintf("%s-%s-%s.csv",
                    $server_data['transfer_id'],
                    microtime(TRUE),
                    rand(1000, 9999));

$temp_filename = sprintf("/tmp/%s", $filename);
$ftp_data = "This is a test";

$fp = fopen($temp_filename, 'w');
fprintf($fp, "%s", $ftp_data);
fclose($fp);

$fp = fopen($temp_filename, 'r');

$ch = curl_init();

curl_setopt($ch, CURLOPT_VERBOSE, TRUE);    
curl_setopt($ch, CURLOPT_URL, sprintf("%s/%s", $server_data['post_url'], $filename));
curl_setopt($ch, CURLOPT_PORT, 21);    
curl_setopt($ch, CURLOPT_USERPWD, sprintf("%s:%s", $server_data['username'], $server_data['password']));

curl_setopt($ch, CURLOPT_UPLOAD, TRUE);
curl_setopt($ch, CURLOPT_INFILE, $fp);
curl_setopt($ch, CURLOPT_INFILESIZE, filesize($temp_filename));

curl_setopt($ch, CURLOPT_USE_SSL, TRUE);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
curl_setopt($ch, CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1_0);
curl_setopt($ch, CURLOPT_SSL_CIPHER_LIST, 'AES-128-CBC');

curl_setopt($ch, CURLOPT_FTP_SSL, CURLOPT_FTPSSLAUTH);
curl_setopt($ch, CURLOPT_FTPSSLAUTH, CURLFTPAUTH_TLS);
curl_setopt($ch, CURLOPT_TIMEOUT, 5);

print_r(array('curl_exec' => curl_exec($ch)));
print_r(array(
           'curl_errno' => curl_errno($ch),
           'curl_error' => curl_error($ch),
        ));

Esta es la sesión de FileZilla.

Status:        Resolving address of ftps.widgetsltd.com
Status:        Connecting to 123.123.123.123:21...
Status:        Connection established, waiting for welcome message...
Trace:         CFtpControlSocket::OnReceive()
Response:  220-Microsoft FTP Service
Response:  220 Widgets, LTD FTP server
Trace:         CFtpControlSocket::SendNextCommand()
Command:   AUTH TLS
Trace:         CFtpControlSocket::OnReceive()
Response:  234 AUTH command ok. Expecting TLS Negotiation.
Status:        Initializing TLS...
Trace:         CTlsSocket::Handshake()
Trace:         CTlsSocket::ContinueHandshake()
Trace:         CTlsSocket::OnSend()
Trace:         CTlsSocket::OnRead()
Trace:         CTlsSocket::ContinueHandshake()
Trace:         CTlsSocket::OnRead()
Trace:         CTlsSocket::ContinueHandshake()
Trace:         TLS Handshake successful
Trace:         Protocol: TLS1.0, Key exchange: RSA, Cipher: AES-128-CBC, MAC: SHA1
Status:        Verifying certificate...
Status:        TLS connection established.
Trace:         CFtpControlSocket::SendNextCommand()
Command:   USER s-rokfri
Trace:         CTlsSocket::OnRead()
Trace:         CFtpControlSocket::OnReceive()
Response:  331 Password required for s-rokfri.
Trace:         CFtpControlSocket::SendNextCommand()
Command:   PASS ********
Trace:         CTlsSocket::OnRead()
Trace:         CFtpControlSocket::OnReceive()
Response:  230-This service and information contained therein belong to Widgets, LTD.
Response:  230 User logged in.
Trace:         CFtpControlSocket::SendNextCommand()
Command:   OPTS UTF8 ON
Trace:         CTlsSocket::OnRead()
Trace:         CFtpControlSocket::OnReceive()
Response:  200 OPTS UTF8 command successful - UTF8 encoding now ON.
Trace:         CFtpControlSocket::SendNextCommand()
Command:   PBSZ 0
Trace:         CTlsSocket::OnRead()
Trace:         CFtpControlSocket::OnReceive()
Response:  200 PBSZ command successful.
Trace:         CFtpControlSocket::SendNextCommand()
Command:   PROT P
Trace:         CTlsSocket::OnRead()
Trace:         CFtpControlSocket::OnReceive()
Response:  200 PROT command successful.
Status:        Connected
Trace:         CFtpControlSocket::ResetOperation(0)
Trace:         CControlSocket::ResetOperation(0)
Trace:         CFileZillaEnginePrivate::ResetOperation(0)
Trace:         Measured latency of 141 ms
Status:        Retrieving directory listing...
Trace:         CFtpControlSocket::SendNextCommand()
Trace:         CFtpControlSocket::ChangeDirSend()
Command:   PWD
Trace:         CTlsSocket::OnRead()
Trace:         CFtpControlSocket::OnReceive()
Response:  257 "/" is current directory.
Trace:         CFtpControlSocket::ResetOperation(0)
Trace:         CControlSocket::ResetOperation(0)
Trace:         CFtpControlSocket::ParseSubcommandResult(0)
Trace:         CFtpControlSocket::ListSubcommandResult()
Trace:           state = 1
Trace:         CFtpControlSocket::ResetOperation(0)
Trace:         CControlSocket::ResetOperation(0)
Status:        Directory listing of "/" successful
Trace:         CFileZillaEnginePrivate::ResetOperation(0)

Aquí está la salida del rizo.

*   Trying 123.123.123.123...
* Connected to ftps.widgetsltd.com (123.123.123.123) port 21 (#0)
* SSL connection timeout
* Closing connection 0
Array
(
    [curl_exec] =>
)
Array
(
    [curl_errno] => 28
    [curl_error] => SSL connection timeout
)