com.google.crypto.tink.subtle

Class SubtleUtil

java.lang.Object

com.google.crypto.tink.subtle.SubtleUtil

public final class SubtleUtil
extends Object

Helper methods.

Method Summary

Modifier and Type	Method and Description
static int	androidApiLevel() Deprecated. Please reimplement this method in your code instead. From within Tink, use Util.getAndroidApiLevel directly.
static BigInteger	bytes2Integer(byte[] bs) Converts an unsigned, big-endian encoded byte array to a non-negative integer (https://tools.ietf.org/html/rfc8017#section-4.1).
static byte[]	integer2Bytes(BigInteger num, int intendedLength) Converts a nonnegative integer to a byte array of a specified length (https://tools.ietf.org/html/rfc8017#section-4.2).
static boolean	isAndroid() Best-effort checks that this is Android.
static byte[]	mgf1(byte[] mgfSeed, int maskLen, Enums.HashType mgfHash) Computes MGF1 as defined at https://tools.ietf.org/html/rfc8017#appendix-B.2.1.
static void	putAsUnsigedInt(ByteBuffer buffer, long value) Inserts value as unsigned into into buffer.
static String	toDigestAlgo(Enums.HashType hash) Returns the digest algorithm name corresponding to a hash type.
static String	toEcdsaAlgo(Enums.HashType hash) Returns the Ecdsa algorithm name corresponding to a hash type.
static String	toRsaSsaPkcs1Algo(Enums.HashType hash) Returns the RSA SSA (Signature with Appendix) PKCS1 algorithm name corresponding to a hash type.

Methods inherited from class java.lang.Object

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

Method Detail

toEcdsaAlgo

public static String toEcdsaAlgo(Enums.HashType hash)
                          throws GeneralSecurityException

Returns the Ecdsa algorithm name corresponding to a hash type.

Parameters:

hash - the hash type

Returns:

the JCE's Ecdsa algorithm name for the hash.

Throws:

GeneralSecurityException - if hash is not supported or is not safe for digital signature.

toRsaSsaPkcs1Algo

public static String toRsaSsaPkcs1Algo(Enums.HashType hash)
                                throws GeneralSecurityException

Returns the RSA SSA (Signature with Appendix) PKCS1 algorithm name corresponding to a hash type.

Parameters:

hash - the hash type.

Returns:

the JCE's RSA SSA PKCS1 algorithm name for the hash.

Throws:

GeneralSecurityException - if hash is not supported or is not safe for digital signature.

toDigestAlgo

public static String toDigestAlgo(Enums.HashType hash)
                           throws GeneralSecurityException

Returns the digest algorithm name corresponding to a hash type.

Parameters:

hash - the hash type.

Returns:

theh JCE's hash algorithm name.

Throws:

GeneralSecurityException - if hash is not supported.

isAndroid

public static boolean isAndroid()

Best-effort checks that this is Android.

Returns:

true if running on Android.

androidApiLevel

@Deprecated
public static int androidApiLevel()

Deprecated. Please reimplement this method in your code instead. From within Tink, use Util.getAndroidApiLevel directly.

Returns the Android API level or -1 if Tink isn't running on Android.

bytes2Integer

public static BigInteger bytes2Integer(byte[] bs)

Converts an unsigned, big-endian encoded byte array to a non-negative integer (https://tools.ietf.org/html/rfc8017#section-4.1).

Parameters:

bs - the byte array to be converted to integer.

Returns:

the corresponding integer.

integer2Bytes

public static byte[] integer2Bytes(BigInteger num,
                                   int intendedLength)
                            throws GeneralSecurityException

Converts a nonnegative integer to a byte array of a specified length (https://tools.ietf.org/html/rfc8017#section-4.2).

Parameters:

num - nonnegative integer to be converted.

intendedLength - intended length of the resulting integer.

Returns:

the corresponding byte array of length intendedLength.

Throws:

GeneralSecurityException

mgf1

public static byte[] mgf1(byte[] mgfSeed,
                          int maskLen,
                          Enums.HashType mgfHash)
                   throws GeneralSecurityException

Computes MGF1 as defined at https://tools.ietf.org/html/rfc8017#appendix-B.2.1.

Throws:

GeneralSecurityException

putAsUnsigedInt

public static void putAsUnsigedInt(ByteBuffer buffer,
                                   long value)
                            throws GeneralSecurityException

Inserts value as unsigned into into buffer.

@throws GeneralSecurityException if not 0 <= value < 2^32.

Throws:

GeneralSecurityException