Using Certificates with cURL


The problem: Using Digital Certificates issued by a Certification Authority (CA) with curl.

The situation: I have a .cer (Digital Certificate) file, .pfx (Personal Information Exchange file i.e., the private key for the certificate). I cannot use either of these to authenticate to the web service as curl would not accept these formats.

The solution:
1) Convert it into PEM format (X.509 certificate) using openssl.
openssl pkcs12 -in abcd.pfx -out abcd.pem
Enter a passphrase and a password.
2) Still you cannot use this with curl because you’d get a few errors.
3) Convert this PEM certificate into three different certificates for the client, the private key and the certification authority certificate.
openssl pkcs12 -in abcd.pfx -out ca.pem -cacerts -nokeys
openssl pkcs12 -in abcd.pfx -out client.pem -clcerts -nokeys
openssl pkcs12 -in abcd.pfx -out key.pem -nocerts
4) Use the following command:
curl -k https://www.thesitetoauthenticate.com/test -v –key key.pem –cacert ca.pem –cert client.pem:

This stuff is also mentioned on curl forum at http://curl.haxx.se/mail/archive-2005-09/0138.html


SSL v2.0 on Internet Explorer

Now that Firefox 2.0 does not have option to enable SSL v2.0, there’s one way it can still be activated in Internet Explorer. Goto Tools -> Internet Options -> Advanced as shown in the screenshot and uncheck all other ciphers except SSL 2.0 and you should be able to check if a particular website supports SSL v2.0.

Activating SSL 2.0 in IE