kubernetes/vendor/gopkg.in/square/go-jose.v2/cipher/ecdh_es.go

// DeriveECDHES derives a shared encryption key using ECDH/ConcatKDF as described in JWE/JWA.
// It is an error to call this function with a private/public key that are not on the same
// curve. Callers must ensure that the keys are valid before calling this function. Output
// size may be at most 1<<16 bytes (64 KiB).
func DeriveECDHES(alg string, apuData, apvData []byte, priv *ecdsa.PrivateKey, pub *ecdsa.PublicKey, size int) []byte { … }

// dSize returns the size in octets for a coordinate on a elliptic curve.
func dSize(curve elliptic.Curve) int { … }

func lengthPrefixed(data []byte) []byte { … }