CODEWITHSUNDEEP
javasecurityhardware-security-module
Christoph
Christoph

Reputation: 11

ECDH KeyAgreement with KDF solely performed in HSM

I have a question regarding JCE and PKCS#11. My goal is to perform a ECDH KeyAgreement and perform a KDF (SHA-256) in an HSM with JCE. The result of the ECDH KeyAgreement (shared secret) shall not be available outside of the HSM like with the PKCS#11 function: "CKM_ECDH1_DERIVE"

Example JCE Code:

// Derive a shared secret with ECDH 
KeyAgreement keyAgreementA = KeyAgreement.getInstance("ECDH", "Some HSM Provider");
keyAgreementA.init(keyPairA.getPrivate());
keyAgreementA.doPhase(keyPairB.getPublic(), true);
byte[] sharedSecret = keyAgreementA.generateSecret(); // <= I don't want that the shared secret is exposed as byte[] outside of the HSM.

// Derive a key from the shared secret and some shared info
MessageDigest hash = MessageDigest.getInstance("SHA-256");
hash.update(sharedSecret);
byte[] derivedSecret = hash.digest(some shared info);

Is it somehow possible in JCE to have something equivalent to the PKCS#11 function "CKM_ECDH1_DERIVE"? My understanding of "CKM_ECDH1_DERIVE" is that I can use it with an KDF (SHA-256) and the plain shared secret (result of the ECDH) is not returned by the HSM. Only the derived key (after KDF) is returned.

Upvotes: 1

Views: 64

Answers (0)

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