com.google.crypto.tink.signature.internal

Class SigUtil

java.lang.Object

com.google.crypto.tink.signature.internal.SigUtil

public final class SigUtil
extends Object

Utility functions to convert to and from signature-related proto.

Method Summary

Modifier and Type	Method and Description
static EllipticCurves.CurveType	toCurveType(com.google.crypto.tink.proto.EllipticCurveType type) Converts protobuf enum EllipticCurveType to raw Java enum {code CurveType}.
static EllipticCurves.EcdsaEncoding	toEcdsaEncoding(com.google.crypto.tink.proto.EcdsaSignatureEncoding encoding) Converts protobuf enum EcdsaSignatureEncoding to raw Java enum {code EllipticCurves.EcdsaEncoding}.
static Enums.HashType	toHashType(com.google.crypto.tink.proto.HashType hash) Converts protobuf enum HashType to raw Java enum Enums.HashType.
static void	validateEcdsaParams(com.google.crypto.tink.proto.EcdsaParams params) Validates Ecdsa's parameters.
static void	validateRsaSsaPkcs1Params(com.google.crypto.tink.proto.RsaSsaPkcs1Params params) Validates RsaSsaPkcs1's parameters.
static void	validateRsaSsaPssParams(com.google.crypto.tink.proto.RsaSsaPssParams params) Validates RsaSsaPss's parameters.

Methods inherited from class java.lang.Object

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

Method Detail

validateEcdsaParams

public static void validateEcdsaParams(com.google.crypto.tink.proto.EcdsaParams params)
                                throws GeneralSecurityException

Validates Ecdsa's parameters. The hash's strength must not be weaker than the curve's strength.

Parameters:

params - the Ecdsa's parameters protocol buffer.

Throws:

GeneralSecurityException - iff it's invalid.

validateRsaSsaPkcs1Params

public static void validateRsaSsaPkcs1Params(com.google.crypto.tink.proto.RsaSsaPkcs1Params params)
                                      throws GeneralSecurityException

Validates RsaSsaPkcs1's parameters. As SHA1 is unsafe, we will only support SHA256 and SHA512 for digital signature.

Parameters:

params - the RsaSsaPkcs1Params protocol buffer.

Throws:

GeneralSecurityException - iff it's invalid.

validateRsaSsaPssParams

public static void validateRsaSsaPssParams(com.google.crypto.tink.proto.RsaSsaPssParams params)
                                    throws GeneralSecurityException

Validates RsaSsaPss's parameters.

• The MGF1 hash function must be the same as the signature hash function.
• The hash function used must be either SHA256, SHA384, or SHA512.
• The salt length must be non-zero.

Parameters:

params - the RsaSsaPssParams protocol buffer.

Throws:

GeneralSecurityException - iff it's invalid.

toHashType

public static Enums.HashType toHashType(com.google.crypto.tink.proto.HashType hash)
                                 throws GeneralSecurityException

Converts protobuf enum HashType to raw Java enum Enums.HashType.

Throws:

GeneralSecurityException - if the HashType is not SHA256, SHA384, or SHA512.

toCurveType

public static EllipticCurves.CurveType toCurveType(com.google.crypto.tink.proto.EllipticCurveType type)
                                            throws GeneralSecurityException

Converts protobuf enum EllipticCurveType to raw Java enum {code CurveType}.

Throws:

GeneralSecurityException

toEcdsaEncoding

public static EllipticCurves.EcdsaEncoding toEcdsaEncoding(com.google.crypto.tink.proto.EcdsaSignatureEncoding encoding)
                                                    throws GeneralSecurityException

Converts protobuf enum EcdsaSignatureEncoding to raw Java enum {code EllipticCurves.EcdsaEncoding}.

Throws:

GeneralSecurityException