public final class PrfBasedKeyDerivationKey extends KeyDerivationKey
An object of this class represents the map which 1) uses the given PRF (as specified by getPrfKey()) to get sufficient key material from the salt, then 2) creates a key for the
parameters as specified in getParameters().getDerivedKeyParameters().
| Modifier and Type | Method and Description |
|---|---|
static PrfBasedKeyDerivationKey |
create(PrfBasedKeyDerivationParameters parameters,
PrfKey prfKey,
Integer idRequirement) |
boolean |
equalsKey(Key other)
Returns true if the key is guaranteed to be equal to
other. |
Integer |
getIdRequirementOrNull()
Returns null if this key has no id requirement, otherwise the required id.
|
PrfBasedKeyDerivationParameters |
getParameters()
Returns a
Parameters object containing all the information about the key which is not
randomly chosen. |
PrfKey |
getPrfKey() |
public static PrfBasedKeyDerivationKey create(PrfBasedKeyDerivationParameters parameters, PrfKey prfKey, @Nullable Integer idRequirement) throws GeneralSecurityException
GeneralSecurityExceptionpublic PrfKey getPrfKey()
public PrfBasedKeyDerivationParameters getParameters()
KeyParameters object containing all the information about the key which is not
randomly chosen.
Implementations need to ensure that getParameters().hasIdRequirement() returns true
if and only if getIdRequirementOrNull is non-null.
getParameters in class KeyDerivationKey@Nullable public Integer getIdRequirementOrNull()
KeySome 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.
getIdRequirementOrNull in class Keypublic boolean equalsKey(Key other)
Keyother.
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.