I am looking for a RSA-SHA1 method. Chilkat support HMAC SHA1 in crypt2 but I do not see an equivalent one for RSA SHA1. I needs this for a Delphi REST OAuth to talk to Xero as a Private Application.
You would use the "Chilkat RSA" object/class, not "Chilkat Crypt2". The Crypt2 object deals with PKCS7 messages (among other things) and not bare RSA encryption/decryption/signatures.