/*

* java-tron is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

* java-tron is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program. If not, see <http://www.gnu.org/licenses/>.

*/

package org.tron.crypto;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.tron.crypto.jce.TronCastleProvider;

import org.tron.trie.TrieImpl;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.security.Provider;

import java.security.Security;

import static java.util.Arrays.copyOfRange;

import static org.tron.utils.ByteUtil.EMPTY_BYTE_ARRAY;

public class Hash {

private static final Logger LOG = LoggerFactory.getLogger(Hash.class);

public static final byte[] EMPTY_TRIE_HASH;

private static final Provider CRYPTO_PROVIDER;

private static final String HASH_256_ALGORITHM_NAME;

private static final String HASH_512_ALGORITHM_NAME;

private static final MessageDigest sha256digest;

static {

Security.addProvider(TronCastleProvider.getInstance());

CRYPTO_PROVIDER = Security.getProvider("SC");

HASH_256_ALGORITHM_NAME = "TRON-KECCAK-256";

HASH_512_ALGORITHM_NAME = "TRON-KECCAK-512";

try {

sha256digest = MessageDigest.getInstance("SHA-256");

} catch (NoSuchAlgorithmException e) {

LOG.error("Can't initialize HashUtils", e);

throw new RuntimeException(e); // Can't happen.

}

TrieImpl impl = new TrieImpl();

EMPTY_TRIE_HASH = sha3(impl.encodeElement(EMPTY_BYTE_ARRAY));

}

/**

* @param input - data for hashing

* @return - sha256 hash of the data

*/

public static byte[] sha256(byte[] input) {

return sha256digest.digest(input);

}

public static byte[] sha3(byte[] input) {

MessageDigest digest;

try {

digest = MessageDigest.getInstance(HASH_256_ALGORITHM_NAME,

CRYPTO_PROVIDER);

digest.update(input);

return digest.digest();

} catch (NoSuchAlgorithmException e) {

LOG.error("Can't find such algorithm", e);

throw new RuntimeException(e);

}

}

public static byte[] sha3(byte[] input1, byte[] input2) {

MessageDigest digest;

try {

digest = MessageDigest.getInstance(HASH_256_ALGORITHM_NAME,

CRYPTO_PROVIDER);

digest.update(input1, 0, input1.length);

digest.update(input2, 0, input2.length);

return digest.digest();

} catch (NoSuchAlgorithmException e) {

LOG.error("Can't find such algorithm", e);

throw new RuntimeException(e);

}

}

/**

* hashing chunk of the data

*

* @param input - data for hash

* @param start - start of hashing chunk

* @param length - length of hashing chunk

* @return - keccak hash of the chunk

*/

public static byte[] sha3(byte[] input, int start, int length) {

MessageDigest digest;

try {

digest = MessageDigest.getInstance(HASH_256_ALGORITHM_NAME,

CRYPTO_PROVIDER);

digest.update(input, start, length);

return digest.digest();

} catch (NoSuchAlgorithmException e) {

LOG.error("Can't find such algorithm", e);

throw new RuntimeException(e);

}

}

public static byte[] sha512(byte[] input) {

MessageDigest digest;

try {

digest = MessageDigest.getInstance(HASH_512_ALGORITHM_NAME,

CRYPTO_PROVIDER);

digest.update(input);

return digest.digest();

} catch (NoSuchAlgorithmException e) {

LOG.error("Can't find such algorithm", e);

throw new RuntimeException(e);

}

}

/**

* Calculates RIGTMOST160(SHA3(input)). This is used in address

* calculations. *

*

* @param input - data

* @return - 20 right bytes of the hash keccak of the data

*/

public static byte[] sha3omit12(byte[] input) {

byte[] hash = sha3(input);

return copyOfRange(hash, 12, hash.length);

}

}