org.bouncycastle.util.Fingerprint Maven / Gradle / Ivy
package org.bouncycastle.util;
import org.bouncycastle.crypto.digests.SHA512tDigest;
import org.bouncycastle.crypto.digests.SHAKEDigest;
/**
* Basic 20 byte finger print class.
*/
public class Fingerprint
{
private static char[] encodingTable =
{
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
private final byte[] fingerprint;
/**
* Base constructor - use SHAKE-256 (160 bits). This is the recommended one as it is also
* produced by the FIPS API.
*
* @param source original data to calculate the fingerprint from.
*/
public Fingerprint(byte[] source)
{
this(source, 160);
}
/**
* Constructor with length - use SHAKE-256 (bitLength bits). This is the recommended one as it is also
* produced by the FIPS API.
*
* @param source original data to calculate the fingerprint from.
*/
public Fingerprint(byte[] source, int bitLength)
{
this.fingerprint = calculateFingerprint(source, bitLength);
}
/**
* Base constructor - for backwards compatibility.
*
* @param source original data to calculate the fingerprint from.
* @param useSHA512t use the old SHA512/160 calculation.
* @deprecated use the SHAKE only version.
*/
public Fingerprint(byte[] source, boolean useSHA512t)
{
if (useSHA512t)
{
this.fingerprint = calculateFingerprintSHA512_160(source);
}
else
{
this.fingerprint = calculateFingerprint(source);
}
}
public byte[] getFingerprint()
{
return Arrays.clone(fingerprint);
}
public String toString()
{
StringBuffer sb = new StringBuffer();
for (int i = 0; i != fingerprint.length; i++)
{
if (i > 0)
{
sb.append(":");
}
sb.append(encodingTable[(fingerprint[i] >>> 4) & 0xf]);
sb.append(encodingTable[fingerprint[i] & 0x0f]);
}
return sb.toString();
}
public boolean equals(Object o)
{
if (o == this)
{
return true;
}
if (o instanceof Fingerprint)
{
return Arrays.areEqual(((Fingerprint)o).fingerprint, fingerprint);
}
return false;
}
public int hashCode()
{
return Arrays.hashCode(fingerprint);
}
/**
* Return a byte array containing a calculated fingerprint for the passed in input data.
* This calculation is compatible with the BC FIPS API.
*
* @param input data to base the fingerprint on.
* @return a byte array containing a 160 bit fingerprint.
*/
public static byte[] calculateFingerprint(byte[] input)
{
return calculateFingerprint(input, 160);
}
/**
* Return a byte array containing a calculated fingerprint for the passed in input data.
* This calculation is compatible with the BC FIPS API.
*
* @param input data to base the fingerprint on.
* @param bitLength bit length of finger print to be produced.
* @return a byte array containing a 20 byte fingerprint.
*/
public static byte[] calculateFingerprint(byte[] input, int bitLength)
{
if (bitLength % 8 != 0)
{
throw new IllegalArgumentException("bitLength must be a multiple of 8");
}
SHAKEDigest digest = new SHAKEDigest(256);
digest.update(input, 0, input.length);
byte[] rv = new byte[bitLength / 8];
digest.doFinal(rv, 0, bitLength / 8);
return rv;
}
/**
* Return a byte array containing a calculated fingerprint for the passed in input data.
* The fingerprint is based on SHA512/160.
*
* @param input data to base the fingerprint on.
* @return a byte array containing a 20 byte fingerprint.
* @deprecated use the SHAKE based version.
*/
public static byte[] calculateFingerprintSHA512_160(byte[] input)
{
SHA512tDigest digest = new SHA512tDigest(160);
digest.update(input, 0, input.length);
byte[] rv = new byte[digest.getDigestSize()];
digest.doFinal(rv, 0);
return rv;
}
}