Notice: Undefined property: stdClass::$data in DrupalMailchimp

Hi Leucocepha. I'd like to help you out. What URL are you viewing when you see the error?

What happens if you execute this code somewhere within your Drupal site?

$result = drupal_http_request('https://us10.api.mailchimp.com/2.0/');

$result should be an array containing the key 'code' with the value '200'. If not, there's an issue making HTTP requests from Drupal that needs to be tracked down.

It's possible that MailChimp is using a different version/configuration of SSL than Facebook and other services you're able to connect to. I don't have access to an instance of IIS to test with.

What I recommend is contacting MailChimp's API support team and asking them about connecting to their API from IIS. They may be aware of an issue or at least be willing to monitor connections from your IP address to see what the problem is.

Looks like you're going to need to create your own SSL certificate if you don't already have one (the .pem file.)

I found a couple of resources here and here that look promising, but my experience is entirely with Linux-based servers so I can't provide any personal insight.

Once you have that, it should just be a case of informing cURL of the file's location: http://stackoverflow.com/a/17409437

I've spent some time investigating this, and the problem seems to be over at mailchimp's api server. This script will fail:

$errno = 0;
$errstr = 0;
stream_socket_client('ssl://us8.api.mailchimp.com:443', $errno, $errstr);

Nesting down, the problem still exists on the command line (Curl 7.38):

~$ curl --head https://us8.api.mailchimp.com/
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: http://curl.haxx.se/docs/sslcerts.html
…

So turning validation off works:

$ curl --head -k https://us8.api.mailchimp.com/
HTTP/1.1 302 Moved Temporarily
…

Using any of the certificate bundles either provided by debian (/etc/ssl/certs/ca-certificates.crt) or the one generated from mozilla.org over at http://curl.haxx.se/docs/caextract.html fails:

~$ curl --head --cacert /etc/ssl/certs/ca-certificates.crt https://us8.api.mailchimp.com/
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: http://curl.haxx.se/docs/sslcerts.html
…

Trying the trick mentioned in the above error message with creating a trusted certificate based on the output from the openssl command fails:

~$ openssl s_client -connect us8.api.mailchimp.com:443 
# Copy paste the content between and including
# -----BEGIN CERTIFICATE-----
# …
# -----END CERTIFICATE-----
# to mailchimp.pem
~$ curl --head --cacert /home/kaare/tmp/mailchimp.pem https://us8.api.mailchimp.com/
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: http://curl.haxx.se/docs/sslcerts.html

And there is no php.ini directive to turn of curl certificate validation, it has to be done when you have the curl handler:

curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);

Which we don't have. Not even in drupal_http_request(). No way to hack around this. Except implementing your own HTTP request function and point the variable drupal_http_request_function to it.

This is a result of increased security in Curl, which are not followed up by MailChimp. I've sent a new support message with pretty much the same debugging info. Waiting for reply.

From Mailchimp support:

After some research, the issue is stemming from the root cert no longer being included in the ca cert package. I'd recommend adding the root CA to the list of certs as mentioned in this StackOverflow article: http://stackoverflow.com/questions/24611640/curl-60-ssl-certificate-unab..., which is shown in the second bullet point in the stackoverflow page.

I'm using Debian 8. For fun I tried to use a replacement /etc/ssl/certs/ca-certificates.crt from Debian 7 and it worked. Trying to manually add the certificates missing in Debian 8 from Debian 7 failed. Further experimentation lead me to /etc/ca-certificates.conf which had some certs disabled, and it is also auto-generated.

A simple

dpkg-reconfigure ca-certificates

Fixed the SSL problem. This should fix it in Ubuntu 15.04 as well.

A possible workaround is to use cURL HTTP Request.

1. Install the module
2. Add this line to your settings.php
   

   // Use curl for drupal_http_request
   $conf['drupal_http_request_function'] = 'chr_curl_http_request';

3. Profit! cURL HTTP Request as of now has the ssl host / peer check disabled by default.

It looks like both proposed fixes work and both are outside the code base of the module. Hopefully, this will improve on the API side in the near future for Debian server administrators.

I'm using xampp localhost on Windows 10 and php 5.6. In php.ini the line "extension=php_openssl.dll" is uncommented.

When refreshing lists i encountered the same error:
"Notice: Undefined property: stdClass::$data in DrupalMailchimp".

Checking "Recent log messages" i got:
"An error occurred requesting list information from Mailchimp. "MailChimp API call to lists/list failed: Error opening socket ssl://us11.api.mailchimp.com:443: "".

#14 fixed the problem for me and now lists are loading in perfectly. Thank you.

I had the same error :
Mailchimp_HttpError: MailChimp API call to templates/list failed: Error opening socket ssl://us7.api.mailchimp.com:443: in DrupalMailchimp->call() (line 89 of xxxxxxx\modules\mailchimp\includes\mailchimp.inc).

I tried the solution #14 and it worked for me ! Thanks !

As of early January 2016, this problem is back for any Linux distributions that use Mozilla's NSS CA-Certificates bundle. This includes Debian 8 Jessie, as well as probably Ubuntu and possibly RHEL/Fedora as well.

I've posted the solution at the end of this comment. Here is why the problem has occurred.

Mailchimp uses a certificate for *.api.mailchimp.com, which is signed with a Root CA that has been removed from Mozilla's trusted bundle (and thereby Debian Linux). This bad root CA is called "GTE_CyberTrust_Global_Root.crt". The reason that this root CA cert was finally removed is that it is insecure - it uses MD5 (not even SHA1!) for a signature algorithm and it is only a 1024 bit RSA key (which is WAY too weak for a Root CA) Mozilla has been trying to get this cert removed since 2014 and it's finally happened and now has trickled down to the "ca-certificates" package in Debian, which was updated earlier this month.

More info here:
Mozilla bug that started it all: https://bugzilla.mozilla.org/show_bug.cgi?id=1047011
Debian bug for Debian to update its certificates: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=806239
Debian package changelog where you can see it being removed last version: http://metadata.ftp-master.debian.org/changelogs/main/c/ca-certificates/...
Official announcement from Mozilla on the removal of weak keys: https://blog.mozilla.org/security/2015/01/28/phase-2-phasing-out-certifi...

So, if you've installed Linux updates (which most everybody responsible did, after last week's unrelated Linux kernel privilege escalation bug), then you should have the new ca-certificates, and your Mailchimp API calls will have stopped working with an error like this:
"MailChimp API call to <em class="placeholder">lists/list</em> failed: Error opening socket ssl://us9.api.mailchimp.com:443: "

Solution

The solution is simple enough - add the missing certificate back into the trusted CA certificates. For Debian or Ubuntu, you can do that with the following steps:

1. Become root: sudo su
2. Add the missing .crt file back into /usr/share/ca-certificates:
   

   cd /usr/share/ca-certificates
   cat > GTE_CyberTrust_Global_Root.crt << __EOF__
   -----BEGIN CERTIFICATE-----
   MIICWjCCAcMCAgGlMA0GCSqGSIb3DQEBBAUAMHUxCzAJBgNVBAYTAlVTMRgwFgYD
   VQQKEw9HVEUgQ29ycG9yYXRpb24xJzAlBgNVBAsTHkdURSBDeWJlclRydXN0IFNv
   bHV0aW9ucywgSW5jLjEjMCEGA1UEAxMaR1RFIEN5YmVyVHJ1c3QgR2xvYmFsIFJv
   b3QwHhcNOTgwODEzMDAyOTAwWhcNMTgwODEzMjM1OTAwWjB1MQswCQYDVQQGEwJV
   UzEYMBYGA1UEChMPR1RFIENvcnBvcmF0aW9uMScwJQYDVQQLEx5HVEUgQ3liZXJU
   cnVzdCBTb2x1dGlvbnMsIEluYy4xIzAhBgNVBAMTGkdURSBDeWJlclRydXN0IEds
   b2JhbCBSb290MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCVD6C28FCc6HrH
   iM3dFw4usJTQGz0O9pTAipTHBsiQl8i4ZBp6fmw8U+E3KHNgf7KXUwefU/ltWJTS
   r41tiGeA5u2ylc9yMcqlHHK6XALnZELn+aks1joNrI1CqiQBOeacPwGFVw1Yh0X4
   04Wqk2kmhXBIgD8SFcd5tB8FLztimQIDAQABMA0GCSqGSIb3DQEBBAUAA4GBAG3r
   GwnpXtlR22ciYaQqPEh346B8pt5zohQDhT37qw4wxYMWM4ETCJ57NE7fQMh017l9
   3PR2VX2bY1QY6fDq81yx2YtCHrnAlU66+tXifPVoYb+O7AWXX1uw16OFNMQkpw0P
   lZPvy5TYnh+dXIVtx6quTx8itc2VrbqnzPmrC3p/
   -----END CERTIFICATE-----
   __EOF__
   

3. Now: dpkg-reconfigure ca-certificates and choose ask to Trust new certificates from certificate authorities? in the first dialog.
4. A second screen appears with a list of all the CA certificates. You should see the GTE_CyberTrust_Global_Root.crt cert we just added at the very top of the list. Press Space Bar and it should toggle the certificate on with an asterisk showing. Now hit Tab and Enter on the OK.
5. You should see output similar to this:
   

   root@yourserver:/usr/share/ca-certificates# dpkg-reconfigure ca-certificates
   Processing triggers for ca-certificates (20141019+deb8u1) ...
   Updating certificates in /etc/ssl/certs... 
   1 added, 0 removed; done.
   Running hooks in /etc/ca-certificates/update.d....done.
   

6. That's it! Test again and it should be working.

I have updated the issue description with this solution so that it's up to date.

#19 fixed it. Thank you very much @damien_vancouver

#14 works for me.

Please note: #14 may cause other problems where drupal_http_request is needed. In my case Services stopped working.

I'm using Debian 8 and PHP7 and was getting
An error occurred requesting list information from MailChimp. "MailChimp API call to lists/list failed: Error opening socket ssl://us7.api.mailchimp.com:443: "

#19 worked for me. Thank you.