Package com.google.crypto.tink.prf

Class HkdfPrfKey

java.lang.Object

com.google.crypto.tink.Key

com.google.crypto.tink.prf.PrfKey

com.google.crypto.tink.prf.HkdfPrfKey

@Immutable
public final class HkdfPrfKey
extends PrfKey

Represents a key computing HKDF PRF.

HKDF PRF is specified in RFC 5869.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	HkdfPrfKey.Builder	Builder for HkdfPrfKey.

Method Summary

Modifier and Type	Method	Description
static HkdfPrfKey.Builder	builder()
boolean	equalsKey(Key o)	Returns true if the key is guaranteed to be equal to other.
java.lang.Integer	getIdRequirementOrNull()	Returns null if this key has no id requirement, otherwise the required id.
SecretBytes	getKeyBytes()
HkdfPrfParameters	getParameters()	Returns the parameters of this key.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

builder

public static HkdfPrfKey.Builder builder()

getKeyBytes

public SecretBytes getKeyBytes()

getParameters

public HkdfPrfParameters getParameters()

Description copied from class: PrfKey

Returns the parameters of this key.

Specified by:

getParameters in class PrfKey

getIdRequirementOrNull

@Nullable
public java.lang.Integer getIdRequirementOrNull()

Description copied from class: Key

Returns null if this key has no id requirement, otherwise the required id.

Some keys, when they are in a keyset, are required to have a certain ID to work properly. This comes from the fact that Tink in some cases prefixes ciphertexts or signatures with the string 0x01<id>, where the ID is encoded in big endian (see the documentation of the key type for details), in which case the key requires a certain ID.

Specified by:

getIdRequirementOrNull in class Key

equalsKey

public boolean equalsKey(Key o)

Description copied from class: Key

Returns true if the key is guaranteed to be equal to other.

Implementations are required to do this in constant time.

Note: this is allowed to return false even if two keys are guaranteed to represent the same function, but are represented differently. For example, a key is allowed to internally store the number of zero-bytes used as padding when a large number is represented as a byte array, and use this in the comparison.

Note: Tink Key objects should typically not override hashCode (because it could risk leaking key material). Hence, they typically also should not override equals.

Specified by:

equalsKey in class Key