Algorithm Identifiers for the HMAC-based Extract-and-Expand Key Derivation Function (HKDF)
Extracted elements (8)
Algorithm identifiers are needed to use HKDF in security protocols such as CMS (RFC 5652) that rely on ASN.1 AlgorithmIdentifier to negotiate or signal key derivation algorithms; this document exists solely to provide those identifiers.
When any of the three HKDF OIDs appear within an ASN.1 AlgorithmIdentifier, the parameters component of that type SHALL be absent.
The ASN.1 module HKDF-OID-2019 defines three KEY-DERIVATION objects (kda-hkdf-with-sha256, kda-hkdf-with-sha384, kda-hkdf-with-sha512), each specifying PARAMS ARE absent and S/MIME capabilities.
Three OIDs are assigned for HKDF used with SHA-256, SHA-384, and SHA-512: id-alg-hkdf-with-sha256 (alg(3) 28), id-alg-hkdf-with-sha384 (alg(3) 29), and id-alg-hkdf-with-sha512 (alg(3) 30), all under the S/MIME algorithm arc (1.2.840.113549.1.9.16.3).
One OID (id-mod-hkdf-oid-2019, value 68) was assigned in the 'SMI Security for S/MIME Module Identifiers (1.2.840.113549.1.9.16.0)' registry for the ASN.1 module defined in this document.
Three OIDs were assigned in the 'SMI Security for S/MIME Algorithms (1.2.840.113549.1.9.16.3)' registry: id-alg-hkdf-with-sha256 (28), id-alg-hkdf-with-sha384 (29), and id-alg-hkdf-with-sha512 (30).
Despite HKDF's apparent simplicity, many security considerations informed its design and analysis; implementers are referred to the HKDF paper (Krawczyk, CRYPTO 2010) for detailed rationale and security analysis beyond this document's scope.
HKDF algorithm identifiers are encoded using ASN.1 AlgorithmIdentifier with BER and DER. The parameters field is absent; only the OID is present for each of the three SHA-based variants.