aiocoap.util.cryptography_additions module

Workaround for https://github.com/pyca/cryptography/issues/5557

These functions could be methods to cryptography.hazmat.primitives.asymmetric.ed25519.{Ed25519PrivateKey, Ed25519PublicKey}, respectively, and are currently implemented manually or using ge25519.

These conversions are not too critical in that they do not run on data an attacker can send arbitrarily (in the most dynamic situation, the keys are distributed through a KDC aka. group manager).

aiocoap.util.cryptography_additions.sk_to_curve25519(ed: cryptography.hazmat.primitives.asymmetric.ed25519.Ed25519PrivateKey) → cryptography.hazmat.primitives.asymmetric.x25519.X25519PrivateKey

aiocoap.util.cryptography_additions.pk_to_curve25519(ed: cryptography.hazmat.primitives.asymmetric.ed25519.Ed25519PublicKey) → cryptography.hazmat.primitives.asymmetric.x25519.X25519PublicKey