I have a signed public key. I wanted to view all the signatures in this OpenPGP public key.
I've got the signature list, and when I tried to get the user IDs of the signers, nothing is returned.
So my doubt is whether an OpenPGP signature contains the signer's user IDs or not.
I used Thunderbird to view signatures, but it also show user ID not found for signature and when I imported the public key corresponing to the private key from that I signed, It showes the user ID of the signer.
My conclusion is OpenPGP signatures don't contain the signer's user IDs. They only contain the key ID. If you also have public key of signer, then it tries to get the user ID from that public key and show you.
Note: I am using the bouncy castle API.