crypto

func ConstantTimeByteCompare ¶

func ConstantTimeByteCompare(x, y []byte) (int, error)

ConstantTimeByteCompare is a constant-time byte comparison of x and y. This function performs an absolute comparison if the two byte slices assuming they represent a big-endian number.

	 error if len(x) != len(y)
  -1 if x <  y
   0 if x == y
  +1 if x >  y

func ECDSAKey ¶

func ECDSAKey(curve elliptic.Curve, d []byte) *ecdsa.PrivateKey

ECDSAKey takes the given elliptic curve, and private key (d) byte slice and returns the private ECDSA key.

func ECDSAKeyFromPoint ¶

func ECDSAKeyFromPoint(curve elliptic.Curve, d *big.Int) *ecdsa.PrivateKey

ECDSAKeyFromPoint takes the given elliptic curve and point and returns the private and public keypair

func ECDSAPublicKey ¶

func ECDSAPublicKey(curve elliptic.Curve, x, y []byte) (*ecdsa.PublicKey, error)

ECDSAPublicKey takes the provide curve and (x, y) coordinates and returns *ecdsa.PublicKey. Returns an error if the given points are not on the curve.

func HMACKeyDerivation ¶

func HMACKeyDerivation(hash func() hash.Hash, bitLen int, key []byte, label, context []byte) ([]byte, error)

HMACKeyDerivation provides an implementation of a NIST-800-108 of a KDF (Key Derivation Function) in Counter Mode. For the purposes of this implantation HMAC is used as the PRF (Pseudorandom function), where the value of `r` is defined as a 4 byte counter.

func VerifySignature ¶

func VerifySignature(key *ecdsa.PublicKey, hash []byte, signature []byte) (bool, error)

VerifySignature takes the provided public key, hash, and asn1 encoded signature and returns whether the given signature is valid.