When I asked about the binding between a key and a scheme, I was not
refering to the scheme used to sign the certificate.
Let's supose that ALICE, running protocol P, want's to send a
PKCS#7 Envelope to BOB, and has a X.509 certificate of BOB's public key
(with rsaEncryption OID on the subjectPublicKeyInfo field). The
certificate was signed with scheme X (eg. DSA) and was correctly verified
by ALICE using that scheme.
Which ENCRYPTION scheme should ALICE use to build the Envelope? (
RSAES-PKCS1-v1_5, RSAES-OAEP , ...)
Probably ALICE would want to use the new RSAES-OAEP, but does BOB support
it?
If I understood you correctly, this binding between the key and the
scheme IS NOT made by a X.509 certificate (except when the retation is
1-1) and has to be built by other means (possibly defined by the protocol P).
I'm I right?
I assume that the source of my initial confusion comes from the fact
that, in PKCS#1, the same OID (rsaEncryption) is used to identify both a
key and a encryption scheme.
Once again, I thank you for your reply
Best regards
- Pedro
Felix