Internet Domain: TCP, UDP, SSL, and TLS
PHP 4, PHP 5. ssl:// & tls:// since PHP 4.3.0 sslv2:// & sslv3:// since PHP 5.0.2
Note: If no transport is specified, tcp:// will be assumed.
- 127.0.0.1
- fe80::1
- www.example.com
- tcp://127.0.0.1
- tcp://fe80::1
- tcp://www.example.com
- udp://www.example.com
- ssl://www.example.com
- sslv2://www.example.com
- sslv3://www.example.com
- tls://www.example.com
Internet Domain sockets expect a port number in addition to a target address. In the case of fsockopen() this is specified in a second parameter and therefore does not impact the formatting of transport URL. With stream_socket_client() and related functions as with traditional URLs however, the port number is specified as a suffix of the transport URL delimited by a colon.
- tcp://127.0.0.1:80
- tcp://[fe80::1]:80
- tcp://www.example.com:80
Note: IPv6 numeric addresses with port numbers
In the second example above, while the IPv4 and hostname examples are left untouched apart from the addition of their colon and portnumber, the IPv6 address is wrapped in square brackets: [fe80::1]. This is to distinguish between the colons used in an IPv6 address and the colon used to delimit the portnumber.
The ssl:// and tls:// transports (available only when openssl support is compiled into PHP) are extensions of the tcp:// transport which include SSL encryption. Since PHP 4.3.0 OpenSSL support must be statically compiled into PHP, since PHP 5.0.0 it may be compiled as a module or statically.
ssl:// will attempt to negotiate an SSL V2, or SSL V3 connection depending on the capabilities and preferences of the remote host. sslv2:// and sslv3:// will select the SSL V2 or SSL V3 protocol explicitly.
Коментарии
Actually, PHP is very able to start with an unencrypted connection and then switch to an encrypted one - refer to http://php.net/stream_socket_enable_crypto .@pablo dot livardo : I think that the problem you found is caused by the difference between the client/server encryption methods used.
The 465 port is used for SMTPS, and the server starts the encryption immediately it receives your connection. So, your code will work.
The 587 port is used for Submission (MSA or Mail Submission Agent) which works like the port 25. The server accepts your connection and doesn't activate the encryption. If you want an encrypted connection on the port 587, you must connect on it without encryption, you must start to dialog with the server (with EHLO) and after that you must ask the server to start the encrypted connection using the STARTTLS command. The server starts the encryption and now you can start as well the encryption on your client.
So, in few words, you can not use :
<?php $fp = fsockopen("tls://mail.example.com", 587, $errno, $errstr); ?>
but you can use:
<?php $fp = stream_socket_client("mail.example.com:587", $errno, $errstr); ?>
and after you send the STARTTLS command, you can enable the crypto:
<?php stream_socket_enable_crypto($fp, true, STREAM_CRYPTO_METHOD_SSLv23_CLIENT); ?>
P.S. My previous note on this page was totally wrong, so I ask the php.net admin to remove it.
:)