How to get SSL certificate info with CURL in PHP?

You will get the certificate as a resource using stream_context_get_params. Plug that resource into $certinfo = openssl_x509_parse($cert['options']['ssl']['peer_certificate']); to get more certificate information.

$url = "http://www.google.com";
$orignal_parse = parse_url($url, PHP_URL_HOST);
$get = stream_context_create(array("ssl" => array("capture_peer_cert" => TRUE)));
$read = stream_socket_client("ssl://".$orignal_parse.":443", $errno, $errstr, 30, STREAM_CLIENT_CONNECT, $get);
$cert = stream_context_get_params($read);
$certinfo = openssl_x509_parse($cert['options']['ssl']['peer_certificate']);
print_r($certinfo);

Example result

Array
(
    [name] => /C=US/ST=California/L=Mountain View/O=Google Inc/CN=www.google.com
    [subject] => Array
        (
            [C] => US
            [ST] => California
            [L] => Mountain View
            [O] => Google Inc
            [CN] => www.google.com
        )

    [hash] => dcdd9741
    [issuer] => Array
        (
            [C] => US
            [O] => Google Inc
            [CN] => Google Internet Authority G2
        )

    [version] => 2
    [serialNumber] => 3007864570594926146
    [validFrom] => 150408141631Z
    [validTo] => 150707000000Z
    [validFrom_time_t] => 1428498991
    [validTo_time_t] => 1436223600
    [purposes] => Array
        (
            [1] => Array
                (
                    [0] => 1
                    [1] => 
                    [2] => sslclient
                )

            [2] => Array
                (
                    [0] => 1
                    [1] => 
                    [2] => sslserver
                )

            [3] => Array
                (
                    [0] => 1
                    [1] => 
                    [2] => nssslserver
                )

            [4] => Array
                (
                    [0] => 
                    [1] => 
                    [2] => smimesign
                )

            [5] => Array
                (
                    [0] => 
                    [1] => 
                    [2] => smimeencrypt
                )

            [6] => Array
                (
                    [0] => 1
                    [1] => 
                    [2] => crlsign
                )

            [7] => Array
                (
                    [0] => 1
                    [1] => 1
                    [2] => any
                )

            [8] => Array
                (
                    [0] => 1
                    [1] => 
                    [2] => ocsphelper
                )

        )

    [extensions] => Array
        (
            [extendedKeyUsage] => TLS Web Server Authentication, TLS Web Client Authentication
            [subjectAltName] => DNS:www.google.com
            [authorityInfoAccess] => CA Issuers - URI:http://pki.google.com/GIAG2.crt
OCSP - URI:http://clients1.google.com/ocsp

            [subjectKeyIdentifier] => FD:1B:28:50:FD:58:F2:8C:12:26:D7:80:E4:94:E7:CD:BA:A2:6A:45
            [basicConstraints] => CA:FALSE
            [authorityKeyIdentifier] => keyid:4A:DD:06:16:1B:BC:F6:68:B5:76:F5:81:B6:BB:62:1A:BA:5A:81:2F

            [certificatePolicies] => Policy: 1.3.6.1.4.1.11129.2.5.1

            [crlDistributionPoints] => URI:http://pki.google.com/GIAG2.crl

        )

)

No. EDIT: A CURLINFO_CERTINFO option has been added to PHP 5.3.2. See http://bugs.php.net/49253

Apparently, that information is being given to you by your proxy in the response headers. If you want to rely on that, you can use curl's CURLOPT_HEADER option to trueto include the headers in the output.

However, to retrieve the certificate without relying on some proxy, you must do

<?php
$g = stream_context_create (array("ssl" => array("capture_peer_cert" => true)));
$r = fopen("https://www.google.com/", "rb", false, $g);
$cont = stream_context_get_params($r);
var_dump($cont["options"]["ssl"]["peer_certificate"]);

You can manipulate the value of $cont["options"]["ssl"]["peer_certificate"] with the OpenSSL extension.

EDIT: This option is better since it doesn't actually make the HTTP request and does not require allow_url_fopen:

<?php
$g = stream_context_create (array("ssl" => array("capture_peer_cert" => true)));
$r = stream_socket_client("ssl://www.google.com:443", $errno, $errstr, 30,
    STREAM_CLIENT_CONNECT, $g);
$cont = stream_context_get_params($r);
var_dump($cont["options"]["ssl"]["peer_certificate"]);

To do this in php and curl:

<?php
if($fp = tmpfile())
{
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL,"https://www.digicert.com/");
    curl_setopt($ch, CURLOPT_STDERR, $fp);
    curl_setopt($ch, CURLOPT_CERTINFO, 1);
    curl_setopt($ch, CURLOPT_VERBOSE, 1);
    curl_setopt($ch, CURLOPT_HEADER, 1);
    curl_setopt($ch, CURLOPT_NOBODY, 1);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST,  2);
    $result = curl_exec($ch);
    curl_errno($ch)==0 or die("Error:".curl_errno($ch)." ".curl_error($ch));
    fseek($fp, 0);//rewind
    $str='';
    while(strlen($str.=fread($fp,8192))==8192);
    echo $str;
    fclose($fp);
}
?>