schmite

Estou com o mesmo problema de:
SSL certificate problem: unable to get local issuer certificate

Já atualizei o openssl:

# openssl version
OpenSSL 1.0.2e 3 Dec 2015

E o curl:

# curl --version
curl 7.38.0 (x86_64-unknown-linux-gnu) libcurl/7.38.0 OpenSSL/1.0.1e zlib/1.2.3 libidn/1.18
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp smtp smtps telnet tftp
Features: IDN Largefile NTLM NTLM_WB SSL libz

Mesmo assim o erro persiste:

[http_request_failed] => Array
                (
                    [0] => SSL certificate problem: unable to get local issuer certificate
                )

Fiz o seguinte trecho de código para efeito de teste:

<?php
    $ch = curl_init();
    $options = array(
                CURLOPT_URL => 'https://qasecommerce.cielo.com.br/servicos/ecommwsec.do',
                CURLOPT_POST => 1,
                CURLOPT_VERBOSE => 1,
                CURLOPT_POSTFIELDS => $postvals,
                CURLOPT_RETURNTRANSFER => 1,
                CURLOPT_CAINFO => './wp-content/plugins/cielo-woocommerce/includes/certificates/VeriSignClass3PublicPrimaryCertificationAuthority-G5.crt',
                CURLOPT_SSLVERSION => 4
    );
    curl_setopt_array($ch, $options);
    $response = curl_exec($ch);
    echo curl_error($ch);
?>

Execu??o:

# php teste.php
* Hostname was NOT found in DNS cache
*   Trying 201.18.41.183...
* Connected to qasecommerce.cielo.com.br (201.18.41.183) port 443 (#0)
* successfully set certificate verify locations:
*   CAfile: ./wp-content/plugins/cielo-woocommerce/includes/certificates/VeriSignClass3PublicPrimaryCertificationAuthority-G5.crt
  CApath: none
* SSL certificate problem: unable to get local issuer certificate
* Closing connection 0

Eu defini o CURLOPT_CAINFO pois é a configura??o que é a mesma setada através ‘sslcertificates’. Se eu n?o setar, ele pega o padr?o do S.O. e consegue validar com sucesso:

# php teste.php
* Hostname was NOT found in DNS cache
*   Trying 201.18.41.183...
* Connected to qasecommerce.cielo.com.br (201.18.41.183) port 443 (#0)
* successfully set certificate verify locations:
*   CAfile: /etc/pki/tls/certs/ca-bundle.crt
  CApath: none
* SSL connection using TLSv1.0 / AES256-SHA
* Server certificate:
* 	 subject: C=BR; ST=Sao Paulo; L=Barueri; O=CIELO S.A.; OU=SI Cielo SS; CN=qasecommerce.cielo.com.br
* 	 start date: 2015-07-16 00:00:00 GMT
* 	 expire date: 2016-07-15 23:59:59 GMT
* 	 subjectAltName: qasecommerce.cielo.com.br matched
* 	 issuer: C=US; O=VeriSign, Inc.; OU=VeriSign Trust Network; OU=Terms of use at https://www.verisign.com/rpa (c)10; CN=VeriSign Class 3 Secure Server CA - G3
* 	 SSL certificate verify ok.
> POST /servicos/ecommwsec.do HTTP/1.1
Host: qasecommerce.cielo.com.br
Accept: */*
Content-Length: 0
Content-Type: application/x-www-form-urlencoded

< HTTP/1.1 200 OK
< Date: Tue, 05 Jan 2016 21:17:27 GMT
* Server Apache/2.2.22 (Unix) mod_ssl/2.2.22 OpenSSL/0.9.8x is not blacklisted
< Server: Apache/2.2.22 (Unix) mod_ssl/2.2.22 OpenSSL/0.9.8x
< Content-Length: 158
< Set-Cookie: JSESSIONID=dxrwWMyGHYyp1fT38tB66csJ2Hw6h2XRjmxPHqYSjM9h2DWYLyPj!1346054325; path=/
< X-Powered-By: Servlet/2.5 JSP/2.1
< Content-Type: text/xml; charset=ISO-8859-1
<
* Connection #0 to host qasecommerce.cielo.com.br left intact

O CA do meu servidor está atualizado. O certificado da CA raíz usado pela Cielo é já está no /etc/pki/tls/certs/ca-bundle.crt.

Inclusive, no próprio WordPress (a partir da vers?o 3.7 se n?o me engano) já inclui e atualiza com as atualiza??es do WP os certificados raízes (/wp-includes/certificates/ca-bundle.crt)
Se eu usar esses certificados funciona perfeitamente.

Estou meio perdido, o que posso fazer?

Thank you for commands. Have been useful even in other situations.
It was not working because I forgot to put: define ('VHP_VARNISH_IP', 'xxxx'); inside the wp-config.php

For me and my colleagues, it would be more obvious if there was a button Varnish HTTP Purge under Settings (similar to WP Super Cache or other plugins) inside that panel the button for Purge Varnish Cache. Also, put a input field to change the IP of the Varnish server inside this panel.