I am having a problem with the Paypal IPN postback verification. The problem came up a month ago, I believe when Paypal updated their security standards and their certificates.
My website is running Magento 1.8.1.0 that uses php-curl under the hood. It runs openSUSE 12.3 and:
PHP 5.3.17
Apache 2.2.29
mysql Ver 14.14 Distrib 5.5.33
OpenSSL 1.0.1j
The curl version installed is:
curl -V
curl 7.28.1 (x86_64-suse-linux-gnu) libcurl/7.28.1 OpenSSL/1.0.1j zlib/1.2.7 libidn/1.25 libssh2/1.4.3
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp scp sftp smtp smtps telnet tftp
Features: AsynchDNS GSS-Negotiate IDN IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP
I enabled curl logs and it seems that the Paypal IPN endpoint (https://www.paypal.com/cgi-bin/webscr) is answering me with a HTTP 500 error:
< HTTP/1.1 500 Internal Server Error
< Date: Fri, 14 Oct 2016 09:44:18 GMT
< Server: Apache/2.2.29 (Linux/SUSE)
< Vary: accept-language,accept-charset
< Accept-Ranges: bytes
< Connection: close
< Content-Type: text/html; charset=iso-8859-1
< Content-Language: en
< X-Pad: avoid browser bug
<
* Closing connection #0
* About to connect() to www.paypal.com port 443 (#0)
* Trying 23.223.77.167...
* connected
* Connected to www.paypal.com (23.223.77.167) port 443 (#0)
* successfully set certificate verify locations:
* CAfile: none
CApath: /etc/ssl/certs/
* error:14077458:SSL routines:SSL23_GET_SERVER_HELLO:tlsv1 unrecognized name
* Closing connection #0
I tried to test the issue from the command line (I don't know if this output is meaningful):
openssl s_client -connect paypal.com:443
CONNECTED(00000003)
depth=1 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert SHA2 High Assurance Server CA
verify error:num=20:unable to get local issuer certificate
verify return:0
---
Certificate chain
0 s:/C=US/ST=California/L=San Jose/O=PayPal, Inc./OU=PayPal Production/CN=paypal.com
i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=/C=US/ST=California/L=San Jose/O=PayPal, Inc./OU=PayPal Production/CN=paypal.com
issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
---
No client certificate CA names sent
---
SSL handshake has read 2791 bytes and written 663 bytes
---
New, TLSv1/SSLv3, Cipher is AES256-SHA256
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
SSL-Session:
Protocol : TLSv1.2
Cipher : AES256-SHA256
Session-ID: 53D6D36E366DBA89D458ABABFB9A08E5A6C470A61DFF00C908B3C8EAB320DB3F
Session-ID-ctx:
Master-Key: 782AB9DDB7319512EFAA3F1843D1E70013E3E8BD384C20584537878DA09B0D9F0E1D6CD39624DD0CDC2BC0DD96616469
Key-Arg : None
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1476950153
Timeout : 300 (sec)
Verify return code: 20 (unable to get local issuer certificate)
---
This is the PHP code that is using php-curl:
/**
* Post back to PayPal to check whether this request is a valid one
*
* @param Zend_Http_Client_Adapter_Interface $httpAdapter
*/
protected function _postBack(Zend_Http_Client_Adapter_Interface $httpAdapter)
{
$sReq = '';
foreach ($this->_request as $k => $v) {
$sReq .= '&'.$k.'='.urlencode($v);
}
$sReq .= "&cmd=_notify-validate";
$sReq = substr($sReq, 1);
$this->_debugData['postback'] = $sReq;
$this->_debugData['postback_to'] = $this->_config->getPaypalUrl();
$httpAdapter->setConfig(array('verifypeer' => $this->_config->verifyPeer));
$httpAdapter->addOption(CURLOPT_SSLVERSION,6);//CURL_SSLVERSION_TLSv1_2
$httpAdapter->write(Zend_Http_Client::POST, $this->_config->getPaypalUrl(), '1.1', array(
'Connection: close', 'User-Agent: XXXXXXXX'
), $sReq);
try {
$response = $httpAdapter->read();
} catch (Exception $e) {
$this->_debugData['http_error'] = array('error' => $e->getMessage(), 'code' => $e->getCode());
throw $e;
}
$this->_debugData['postback_result'] = $response;
$response = preg_split('/^\r?$/m', $response, 2);
$response = trim($response[1]);
if ($response != 'VERIFIED') {
throw new Exception('PayPal IPN postback failure. See ' . self::DEFAULT_LOG_FILE . ' for details.');
}
unset($this->_debugData['postback'], $this->_debugData['postback_result']);
}
And:
/**
* Array of CURL options
*
* @var array
*/
protected $_options = array();
/**
* Apply current configuration array to transport resource
*
* @return Varien_Http_Adapter_Curl
*/
protected function _applyConfig()
{
if (empty($this->_config)) {
return $this;
}
// apply additional options to cURL
foreach ($this->_options as $option => $value) {
curl_setopt($this->_getResource(), $option, $value);
}
$verifyPeer = isset($this->_config['verifypeer']) ? $this->_config['verifypeer'] : 0;
curl_setopt($this->_getResource(), CURLOPT_SSL_VERIFYPEER, $verifyPeer);
$verifyHost = isset($this->_config['verifyhost']) ? $this->_config['verifyhost'] : 0;
curl_setopt($this->_getResource(), CURLOPT_SSL_VERIFYHOST, $verifyHost);
foreach ($this->_config as $param => $curlOption) {
if (array_key_exists($param, $this->_allowedParams)) {
curl_setopt($this->_getResource(), $this->_allowedParams[$param], $this->_config[$param]);
}
}
return $this;
}
/**
* Set array of additional cURL options
*
* @param array $options
* @return Varien_Http_Adapter_Curl
*/
public function setOptions(array $options = array())
{
$this->_options = $options;
return $this;
}
/**
* Add additional option to cURL
*
* @param int $option the CURLOPT_* constants
* @param mixed $value
* @return Varien_Http_Adapter_Curl
*/
public function addOption($option, $value)
{
$this->_options[$option] = $value;
return $this;
}
/**
* Set the configuration array for the adapter
*
* @param array $config
* @return Varien_Http_Adapter_Curl
*/
public function setConfig($config = array())
{
$this->_config = $config;
return $this;
}
/**
* Connect to the remote server
*
* @deprecated since 1.4.0.0-rc1
* @param string $host
* @param int $port
* @param boolean $secure
* @return Varien_Http_Adapter_Curl
*/
public function connect($host, $port = 80, $secure = false)
{
return $this->_applyConfig();
}
/**
* Send request to the remote server
*
* @param string $method
* @param Zend_Uri_Http $url
* @param string $http_ver
* @param array $headers
* @param string $body
* @return string Request as text
*/
public function write($method, $url, $http_ver = '1.1', $headers = array(), $body = '')
{
if ($url instanceof Zend_Uri_Http) {
$url = $url->getUri();
}
$this->_applyConfig();
curl_setopt($this->_getResource(), CURLOPT_VERBOSE, true);
$handle = fopen('/srv/www/htdocs/MascagniB2C/var/log/curl.log', 'a+');
curl_setopt($this->_getResource(), CURLOPT_STDERR, $handle);
// set url to post to
curl_setopt($this->_getResource(), CURLOPT_URL, $url);
curl_setopt($this->_getResource(), CURLOPT_RETURNTRANSFER, true);
if ($method == Zend_Http_Client::POST) {
curl_setopt($this->_getResource(), CURLOPT_POST, true);
curl_setopt($this->_getResource(), CURLOPT_POSTFIELDS, $body);
}
elseif ($method == Zend_Http_Client::GET) {
curl_setopt($this->_getResource(), CURLOPT_HTTPGET, true);
}
if (is_array($headers)) {
curl_setopt($this->_getResource(), CURLOPT_HTTPHEADER, $headers);
}
/**
* @internal Curl options setter have to be re-factored
*/
$header = isset($this->_config['header']) ? $this->_config['header'] : true;
curl_setopt($this->_getResource(), CURLOPT_HEADER, $header);
return $body;
}
Can you please guide me understanding where the problem lies in my openssl configuration (or am I looking in the wrong direction)? Am I missing a certificate?
UPDATE
A suggested I tried running:
openssl s_client -CApath /etc/ssl/certs/ -connect paypal.com:443
CONNECTED(00000003)
depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert High Assurance EV Root CA
verify return:1
depth=1 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert SHA2 High Assurance Server CA
verify return:1
depth=0 C = US, ST = California, L = San Jose, O = "PayPal, Inc.", OU = PayPal Production, CN = paypal.com
verify return:1
---
Certificate chain
0 s:/C=US/ST=California/L=San Jose/O=PayPal, Inc./OU=PayPal Production/CN=paypal.com
i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=/C=US/ST=California/L=San Jose/O=PayPal, Inc./OU=PayPal Production/CN=paypal.com
issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
---
No client certificate CA names sent
---
SSL handshake has read 2791 bytes and written 663 bytes
---
New, TLSv1/SSLv3, Cipher is AES256-SHA256
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
SSL-Session:
Protocol : TLSv1.2
Cipher : AES256-SHA256
Session-ID: 78A62BA404C7656931D4FA5658820B4000CD69DBB82BAEB8E725ADBBE2B3E9C0
Session-ID-ctx:
Master-Key: 725C7887E3F5BABC6BF878DDD4C2F9A246A08382BB259C700E8D74C95FF75D6E98FF2979BBB8661C7525D36956397179
Key-Arg : None
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1476950900
Timeout : 300 (sec)
Verify return code: 0 (ok)
---
openssl s_client -CApath /etc/ssl/certs/ -connect paypal.com:443and let's see if the verify return code isn't 20.