Magento error: Unknown cipher in list: TLSv1

On attempt to install some Magento extension via Downloader/Magento Connect it shows the following error message:
Unknown cipher in list: TLSv1

Cause

CURLOPT_SSL_CIPHER_LIST constant is changed to CURLOPT_SSLVERSION with newer curl library.

Solution

Apply the following correction against downloader/lib/Mage/HTTP/Client/Curl.php:

--- downloader/lib/Mage/HTTP/Client/Curl.php
+++ downloader/lib/Mage/HTTP/Client/Curl.php
@@ -374,7 +374,7 @@
         $this->_ch = curl_init();
         $this->curlOption(CURLOPT_URL, $uriModified);
         $this->curlOption(CURLOPT_SSL_VERIFYPEER, true);
-        $this->curlOption(CURLOPT_SSL_CIPHER_LIST, 'TLSv1');
+        $this->curlOption(CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1);
         $this->getCurlMethodSettings($method, $params, $isAuthorizationRequired);
 
         if(count($this->_headers)) {

If you have any difficulties with solving this problem or got a similar one, please let us know in comments below, so we can find the solution together.

Posted in: Magento Connect