curl error 35 : unknown SSL protocol error in connection

Question

$ curl -I https://9.185.173.135
curl: (35) Unknown SSL protocol error in connection to 9.185.173.135:443

This is an secured page that I need to access.

Answer 1

To Rudi : Thanks for the hint, that tells me a hell lot of info.

Somehow the admin of the secured page "refreshes" the state of certifications every day. So although I got blocked from accessing it yesterday, it generously lets me to grab another certificate and add it to the exception list of Firefox.

So everything is working, and I really learn something from yesterday's experience.

Answer 2

I got the same error when running curl/httpie against a Tomcat server on my localhost deployed from Eclipse. It turns out that default server.xml deployed by Eclipse disables https. Specifically, the section below is commented out in server.xml.

<Connector port="8443" protocol="org.apache.coyote.http11.Http11NioProtocol"
           maxThreads="150" SSLEnabled="true" scheme="https" secure="true"
           clientAuth="false" sslProtocol="TLS" />

After uncommenting it out and adding the two keystore parameters, the curl command starts working (with --insecure option if the certificate is self-signed).

<Connector port="8443" protocol="org.apache.coyote.http11.Http11NioProtocol"
           maxThreads="150" SSLEnabled="true" scheme="https" secure="true"
           clientAuth="false" sslProtocol="TLS" />
           keystoreFile="/path/to/your/keystore"
           keystorePass="yourpass" />

Answer 3

try this

curl_setopt($ch, CURLOPT_SSLVERSION, CURL_SSLVERSION_SSLv3); // Force SSLv3 to fix Unknown SSL Protocol error

Answer 4

i have some solutions that fix the issue for me:

1] try update your curl/php/apache [ yum update ]

2] restart apache

Those worked for me!

Answer 5

You can use --tlsv1 option to solve the issue in case the curl version is below 7.34

 curl -I --tlsv1 https://9.185.173.135

Answer 6

I had the same error after updating my SSL certificate on the target SSL site. My source OS was Centos 6 and updating to a new curl version solved it. *Note I was already using the curl -k (insecure option) but I would still get that error. Essentially this error is caused by nss or openssl being out of date. yum -y install curl nss openssl Remember if you have a web application like PHP calling curl you will need to restart Apache to make the update take effect.

I've updated based on this guide: http://realtechtalk.com/curl_35_Unknown_SSL_protocol_error_in_connection_Solution_Centos-1988-articles