Dear all, I'm currently working on a digital signature project based on RSASSA-PKCS1-v1.5. As far as I understand I "just" need to create an SHA1 digest of what I should sign and encryt it with an RSA private key to get the digital signature. I've made some test with openssl, python and java and I effectively get the same digital signature for my content that can be verified with my RSA public key. Now I'm totally stopped by the need to provide the key id for my RSA keypair. Can someone here can point me to a good reading concerning what is the "key id" for an RSA priv+pub keypair (if it makes sens to talk about for a key id without further information)? Or explain briefly what it is and in what context I can have one associated with a RSA keypair? (maybe I need to create a minimalistic PKI to get such an information? All of this is absolutely unclear to me).
If it's another RTFM question, feel free to shout and please point me to it, I definitely can't find what I'm looking for. Thanks and best regards, any help to the crypto-novice I am would be much appreciated, Raphaël P.S. Here is how I generate my keypair and how I use it to create my digital signature: private key generation: openssl genrsa -out testkey.pem 2048 public key extraction: openssl rsa -in testkey.pem -pubout -out testkey.pub SHA1+RSA signature: openssl dgst -sha1 -sign testkey.pem -out test.txt.sha1 test.txt Sig verification: openssl dgst -sha1 -verify testkey.pub -signature test.txt.sha1 test.txt
