Digitally sign token with RSA-SHA1 Base64 encryption

I am trying to interface with Google Services using AuthSub: AuthSub Authentication

In the documentation it states this:

The signature for the secure token. This value must be a signature made 
by the private key corresponding to the certificate provided during 
registration. It must be encoded in BASE64, and must use the SHA-1 
with RSA using PKCS#1 padding algorithm.

I have used openssl to create public/private keys and have successfully uploaded (I think) my certificate to google. What component can I use to accomplish the digitally signing of the token?

Thanks.

From stackoverflow

• http://stackoverflow.com/questions/1402380/encryption-library-for-delphi ?

  M Schenkel : Thanks, I will check this out.

• I've recently implemented some of the OpenSSL API in Delphi based on the work by Marco Ferrante at http://www.disi.unige.it/person/FerranteM/delphiopenssl/. There are some good samples on the site too. Take a look at the EVP_Sign... functions.

  M Schenkel : Thanks - I will check this out. I think most of my problems at this point are a lack of understanding how encryptition works.

  shunty : I was in the same situation about a month ago. After a lot of Googling and reading the OpenSSL docs I think I know a lot more than I did! If you're using a unicode Delphi version then you need to change the PChar definitions for something like PAnsiChar or PByte - I found PByte to be preferable once I'd learned how to use TEncoding and TBytes. However for the Base64 bit I'd just use the Jedi JCL (or DCPCrypt).