var (
	ErrImport                     = errors.New("ecies: failed to import key")
	ErrInvalidCurve               = errors.New("ecies: invalid elliptic curve")
	ErrInvalidPublicKey           = errors.New("ecies: invalid public key")
	ErrSharedKeyIsPointAtInfinity = errors.New("ecies: shared key is point at infinity")
	ErrSharedKeyTooBig            = errors.New("ecies: shared key params are too big")
)

var (
	ErrSharedTooLong  = errors.New("ecies: shared secret is too long")
	ErrInvalidMessage = errors.New("ecies: invalid message")
)

var (
	DefaultCurve                  = ethcrypto.S256()
	ErrUnsupportedECDHAlgorithm   = errors.New("ecies: unsupported ECDH algorithm")
	ErrUnsupportedECIESParameters = errors.New("ecies: unsupported ECIES parameters")
	ErrInvalidKeyLen              = fmt.Errorf("ecies: invalid key size (> %d) in ECIESParams", maxKeyLen)
)

var (
	ECIES_AES128_SHA256 = &ECIESParams{
		Hash:      sha256.New,
		hashAlgo:  crypto.SHA256,
		Cipher:    aes.NewCipher,
		BlockSize: aes.BlockSize,
		KeyLen:    16,
	}

	ECIES_AES192_SHA384 = &ECIESParams{
		Hash:      sha512.New384,
		hashAlgo:  crypto.SHA384,
		Cipher:    aes.NewCipher,
		BlockSize: aes.BlockSize,
		KeyLen:    24,
	}

	ECIES_AES256_SHA256 = &ECIESParams{
		Hash:      sha256.New,
		hashAlgo:  crypto.SHA256,
		Cipher:    aes.NewCipher,
		BlockSize: aes.BlockSize,
		KeyLen:    32,
	}

	ECIES_AES256_SHA384 = &ECIESParams{
		Hash:      sha512.New384,
		hashAlgo:  crypto.SHA384,
		Cipher:    aes.NewCipher,
		BlockSize: aes.BlockSize,
		KeyLen:    32,
	}

	ECIES_AES256_SHA512 = &ECIESParams{
		Hash:      sha512.New,
		hashAlgo:  crypto.SHA512,
		Cipher:    aes.NewCipher,
		BlockSize: aes.BlockSize,
		KeyLen:    32,
	}
)

type ECIESParams struct {
	Hash func() hash.Hash // hash function

	Cipher    func([]byte) (cipher.Block, error) // symmetric cipher
	BlockSize int                                // block size of symmetric cipher
	KeyLen    int                                // length of symmetric key
	// contains filtered or unexported fields
}

type PrivateKey struct {
	PublicKey
	D *big.Int
}

type PublicKey struct {
	X *big.Int
	Y *big.Int
	elliptic.Curve
	Params *ECIESParams
}