aboutsummaryrefslogtreecommitdiff
path: root/src/cz/crcs/ectester/common/util/ECUtil.java
diff options
context:
space:
mode:
Diffstat (limited to 'src/cz/crcs/ectester/common/util/ECUtil.java')
-rw-r--r--src/cz/crcs/ectester/common/util/ECUtil.java485
1 files changed, 0 insertions, 485 deletions
diff --git a/src/cz/crcs/ectester/common/util/ECUtil.java b/src/cz/crcs/ectester/common/util/ECUtil.java
deleted file mode 100644
index e8c0a11..0000000
--- a/src/cz/crcs/ectester/common/util/ECUtil.java
+++ /dev/null
@@ -1,485 +0,0 @@
-package cz.crcs.ectester.common.util;
-
-import cz.crcs.ectester.applet.EC_Consts;
-import cz.crcs.ectester.common.ec.*;
-import cz.crcs.ectester.data.EC_Store;
-import cz.crcs.ectester.standalone.consts.SignatureIdent;
-import org.bouncycastle.asn1.*;
-import org.bouncycastle.crypto.digests.SHA1Digest;
-import org.bouncycastle.crypto.signers.PlainDSAEncoding;
-import org.bouncycastle.crypto.signers.StandardDSAEncoding;
-
-import java.io.ByteArrayInputStream;
-import java.io.FileInputStream;
-import java.io.IOException;
-import java.math.BigInteger;
-import java.nio.charset.StandardCharsets;
-import java.security.KeyPair;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-import java.security.interfaces.ECKey;
-import java.security.interfaces.ECPrivateKey;
-import java.security.interfaces.ECPublicKey;
-import java.security.spec.*;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Random;
-
-/**
- * @author Jan Jancar johny@neuromancer.sk
- */
-public class ECUtil {
- private static Random rand = new Random();
-
- public static byte[] toByteArray(BigInteger what, int bits) {
- byte[] raw = what.toByteArray();
- int bytes = (bits + 7) / 8;
- if (raw.length < bytes) {
- byte[] result = new byte[bytes];
- System.arraycopy(raw, 0, result, bytes - raw.length, raw.length);
- return result;
- }
- if (bytes < raw.length) {
- byte[] result = new byte[bytes];
- System.arraycopy(raw, raw.length - bytes, result, 0, bytes);
- return result;
- }
- return raw;
- }
-
- public static byte[] toX962Compressed(byte[][] point) {
- if (point.length != 2) {
- return null;
- }
- byte ybit = (byte) (point[1][point[1].length - 1] % 2);
- return ByteUtil.concatenate(new byte[]{(byte) (0x02 | ybit)}, point[0]);
- }
-
- public static byte[] toX962Compressed(ECPoint point, int bits) {
- if (point.equals(ECPoint.POINT_INFINITY)) {
- return new byte[]{0};
- }
- byte[] x = toByteArray(point.getAffineX(), bits);
- byte marker = (byte) (0x02 | point.getAffineY().mod(BigInteger.valueOf(2)).byteValue());
- return ByteUtil.concatenate(new byte[]{marker}, x);
- }
-
- public static byte[] toX962Compressed(ECPoint point, ECParameterSpec spec) {
- return toX962Compressed(point, spec.getOrder().bitLength());
- }
-
- public static byte[] toX962Uncompressed(ECPoint point, int bits) {
- if (point.equals(ECPoint.POINT_INFINITY)) {
- return new byte[]{0};
- }
- byte[] x = toByteArray(point.getAffineX(), bits);
- byte[] y = toByteArray(point.getAffineY(), bits);
- return ByteUtil.concatenate(new byte[]{0x04}, x, y);
- }
-
- public static byte[] toX962Uncompressed(ECPoint point, ECParameterSpec spec) {
- return toX962Uncompressed(point, spec.getOrder().bitLength());
- }
-
- public static byte[] toX962Hybrid(ECPoint point, int bits) {
- if (point.equals(ECPoint.POINT_INFINITY)) {
- return new byte[]{0};
- }
- byte[] x = toByteArray(point.getAffineX(), bits);
- byte[] y = toByteArray(point.getAffineY(), bits);
- byte marker = (byte) (0x06 | point.getAffineY().mod(BigInteger.valueOf(2)).byteValue());
- return ByteUtil.concatenate(new byte[]{marker}, x, y);
- }
-
- public static byte[] toX962Hybrid(ECPoint point, EllipticCurve curve) {
- return toX962Hybrid(point, curve.getField().getFieldSize());
- }
-
- public static byte[] toX962Hybrid(ECPoint point, ECParameterSpec spec) {
- return toX962Hybrid(point, spec.getCurve());
- }
-
- private static boolean isResidue(BigInteger a, BigInteger p) {
- BigInteger exponent = p.subtract(BigInteger.ONE).divide(BigInteger.valueOf(2));
- BigInteger result = a.modPow(exponent, p);
- return result.equals(BigInteger.ONE);
- }
-
- private static BigInteger modSqrt(BigInteger a, BigInteger p) {
- BigInteger q = p.subtract(BigInteger.ONE);
- int s = 0;
- while (q.mod(BigInteger.valueOf(2)).equals(BigInteger.ZERO)) {
- q = q.divide(BigInteger.valueOf(2));
- s++;
- }
-
- BigInteger z = BigInteger.ONE;
- do {
- z = z.add(BigInteger.ONE);
- } while (isResidue(z, p));
-
- BigInteger m = BigInteger.valueOf(s);
- BigInteger c = z.modPow(q, p);
- BigInteger t = a.modPow(q, p);
- BigInteger rExponent = q.add(BigInteger.ONE).divide(BigInteger.valueOf(2));
- BigInteger r = a.modPow(rExponent, p);
-
- while (!t.equals(BigInteger.ONE)) {
- int i = 0;
- BigInteger exponent;
- do {
- exponent = BigInteger.valueOf(2).pow(++i);
- } while (!t.modPow(exponent, p).equals(BigInteger.ONE));
-
- BigInteger twoExponent = m.subtract(BigInteger.valueOf(i + 1));
- BigInteger b = c.modPow(BigInteger.valueOf(2).modPow(twoExponent, p), p);
- m = BigInteger.valueOf(i);
- c = b.modPow(BigInteger.valueOf(2), p);
- t = t.multiply(c).mod(p);
- r = r.multiply(b).mod(p);
- }
- return r;
- }
-
- public static ECPoint fromX962(byte[] data, EllipticCurve curve) {
- if (data == null) {
- return null;
- }
- if (data[0] == 0x04 || data[0] == 0x06 || data[0] == 0x07) {
- int len = (data.length - 1) / 2;
- byte[] xbytes = new byte[len];
- System.arraycopy(data, 1, xbytes, 0, len);
- byte[] ybytes = new byte[len];
- System.arraycopy(data, 1 + len, ybytes, 0, len);
- return new ECPoint(new BigInteger(1, xbytes), new BigInteger(1, ybytes));
- } else if (data[0] == 0x02 || data[0] == 0x03) {
- if (curve == null) {
- throw new IllegalArgumentException();
- }
- byte[] xbytes = new byte[data.length - 1];
- System.arraycopy(data, 1, xbytes, 0, data.length - 1);
- BigInteger x = new BigInteger(1, xbytes);
- BigInteger a = curve.getA();
- BigInteger b = curve.getB();
-
- ECField field = curve.getField();
- if (field instanceof ECFieldFp) {
- BigInteger p = ((ECFieldFp) field).getP();
- BigInteger alpha = x.modPow(BigInteger.valueOf(3), p);
- alpha = alpha.add(x.multiply(a));
- alpha = alpha.add(b);
-
- if (!isResidue(alpha, p)) {
- throw new IllegalArgumentException();
- }
-
- BigInteger beta = modSqrt(alpha, p);
- if (beta.getLowestSetBit() == 0) {
- // rightmost bit is one
- if (data[0] == 0x02) {
- // yp is 0
- beta = p.subtract(beta);
- }
- } else {
- // rightmost bit is zero
- if (data[0] == 0x03) {
- // yp is 1
- beta = p.subtract(beta);
- }
- }
-
- return new ECPoint(x, beta);
- } else if (field instanceof ECFieldF2m) {
- //TODO
- throw new UnsupportedOperationException();
- }
- return null;
- } else {
- throw new IllegalArgumentException();
- }
- }
-
- private static byte[] hashCurve(EC_Curve curve) {
- int bytes = (curve.getBits() + 7) / 8;
- byte[] result = new byte[bytes];
- SHA1Digest digest = new SHA1Digest();
- byte[] curveName = curve.getId().getBytes(StandardCharsets.US_ASCII);
- digest.update(curveName, 0, curveName.length);
- int written = 0;
- while (written < bytes) {
- byte[] dig = new byte[digest.getDigestSize()];
- digest.doFinal(dig, 0);
- int toWrite = Math.min(digest.getDigestSize(), bytes - written);
- System.arraycopy(dig, 0, result, written, toWrite);
- written += toWrite;
- digest.update(dig, 0, dig.length);
- }
- return result;
- }
-
- public static EC_Params fullRandomKey(EC_Curve curve) {
- int bytes = (curve.getBits() + 7) / 8;
- byte[] result = new byte[bytes];
- rand.nextBytes(result);
- BigInteger priv = new BigInteger(1, result);
- BigInteger order = new BigInteger(1, curve.getParam(EC_Consts.PARAMETER_R)[0]);
- priv = priv.mod(order);
- return new EC_Params(EC_Consts.PARAMETER_S, new byte[][]{toByteArray(priv, curve.getBits())});
- }
-
- public static EC_Params fixedRandomKey(EC_Curve curve) {
- byte[] hash = hashCurve(curve);
- BigInteger priv = new BigInteger(1, hash);
- BigInteger order = new BigInteger(1, curve.getParam(EC_Consts.PARAMETER_R)[0]);
- priv = priv.mod(order);
- return new EC_Params(EC_Consts.PARAMETER_S, new byte[][]{toByteArray(priv, curve.getBits())});
- }
-
- private static BigInteger computeRHS(BigInteger x, BigInteger a, BigInteger b, BigInteger p) {
- BigInteger rhs = x.modPow(BigInteger.valueOf(3), p);
- rhs = rhs.add(a.multiply(x)).mod(p);
- rhs = rhs.add(b).mod(p);
- return rhs;
- }
-
- public static EC_Params fullRandomPoint(EC_Curve curve) {
- EllipticCurve ecCurve = curve.toCurve();
-
- BigInteger p;
- if (ecCurve.getField() instanceof ECFieldFp) {
- ECFieldFp fp = (ECFieldFp) ecCurve.getField();
- p = fp.getP();
- if (!p.isProbablePrime(20)) {
- return null;
- }
- } else {
- //TODO
- return null;
- }
- BigInteger x;
- BigInteger rhs;
- do {
- x = new BigInteger(ecCurve.getField().getFieldSize(), rand).mod(p);
- rhs = computeRHS(x, ecCurve.getA(), ecCurve.getB(), p);
- } while (!isResidue(rhs, p));
- BigInteger y = modSqrt(rhs, p);
- if (rand.nextBoolean()) {
- y = p.subtract(y);
- }
-
- byte[] xArr = toByteArray(x, ecCurve.getField().getFieldSize());
- byte[] yArr = toByteArray(y, ecCurve.getField().getFieldSize());
- return new EC_Params(EC_Consts.PARAMETER_W, new byte[][]{xArr, yArr});
- }
-
- public static EC_Params fixedRandomPoint(EC_Curve curve) {
- EllipticCurve ecCurve = curve.toCurve();
-
- BigInteger p;
- if (ecCurve.getField() instanceof ECFieldFp) {
- ECFieldFp fp = (ECFieldFp) ecCurve.getField();
- p = fp.getP();
- if (!p.isProbablePrime(20)) {
- return null;
- }
- } else {
- //TODO
- return null;
- }
-
- BigInteger x = new BigInteger(1, hashCurve(curve)).mod(p);
- BigInteger rhs = computeRHS(x, ecCurve.getA(), ecCurve.getB(), p);
- while (!isResidue(rhs, p)) {
- x = x.add(BigInteger.ONE).mod(p);
- rhs = computeRHS(x, ecCurve.getA(), ecCurve.getB(), p);
- }
- BigInteger y = modSqrt(rhs, p);
- if (y.bitCount() % 2 == 0) {
- y = p.subtract(y);
- }
-
- byte[] xArr = toByteArray(x, ecCurve.getField().getFieldSize());
- byte[] yArr = toByteArray(y, ecCurve.getField().getFieldSize());
- return new EC_Params(EC_Consts.PARAMETER_W, new byte[][]{xArr, yArr});
- }
-
- public static ECPoint toPoint(EC_Params params) {
- return new ECPoint(
- new BigInteger(1, params.getParam(EC_Consts.PARAMETER_W)[0]),
- new BigInteger(1, params.getParam(EC_Consts.PARAMETER_W)[1]));
- }
-
- public static BigInteger toScalar(EC_Params params) {
- return new BigInteger(1, params.getParam(EC_Consts.PARAMETER_S)[0]);
- }
-
- public static ECPublicKey toPublicKey(EC_Key.Public pubkey) {
- if (pubkey == null) {
- return null;
- }
- EC_Curve curve = EC_Store.getInstance().getObject(EC_Curve.class, pubkey.getCurve());
- if (curve == null) {
- throw new IllegalArgumentException("pubkey curve not found: " + pubkey.getCurve());
- }
- return new RawECPublicKey(toPoint(pubkey), curve.toSpec());
- }
-
- public static ECPrivateKey toPrivateKey(EC_Key.Private privkey) {
- if (privkey == null) {
- return null;
- }
- EC_Curve curve = EC_Store.getInstance().getObject(EC_Curve.class, privkey.getCurve());
- if (curve == null) {
- throw new IllegalArgumentException("privkey curve not found: " + privkey.getCurve());
- }
- return new RawECPrivateKey(toScalar(privkey), curve.toSpec());
- }
-
- public static KeyPair toKeyPair(EC_Keypair kp) {
- if (kp == null) {
- return null;
- }
- EC_Curve curve = EC_Store.getInstance().getObject(EC_Curve.class, kp.getCurve());
- if (curve == null) {
- throw new IllegalArgumentException("keypair curve not found: " + kp.getCurve());
- }
- ECPublicKey pubkey = new RawECPublicKey(toPoint(kp), curve.toSpec());
- ECPrivateKey privkey = new RawECPrivateKey(toScalar(kp), curve.toSpec());
- return new KeyPair(pubkey, privkey);
- }
-
- public static BigInteger recoverSignatureNonce(byte[] signature, byte[] data, BigInteger privkey, ECParameterSpec params, String hashAlgo, String sigType) {
- SignatureIdent sigIdent = SignatureIdent.get(hashAlgo + "with" + sigType);
- if (sigIdent == null) {
- return null;
- }
- return recoverSignatureNonce(signature, data, privkey, params, sigIdent);
- }
-
- public static BigInteger recoverSignatureNonce(byte[] signature, byte[] data, BigInteger privkey, ECParameterSpec params, SignatureIdent sigIdent) {
- // Parse the types out of SignatureIdent.
- String hashAlgo = sigIdent.getHashAlgo();
- String sigType = sigIdent.getSigType();
- if (sigType == null) {
- sigType = sigIdent.toString();
- }
- // We do not know how to reconstruct those nonces so far.
- // sigType.contains("ECKCDSA") || sigType.contains("ECNR") || sigType.contains("SM2")
- if (!sigType.contains("ECDSA")) {
- return null;
- }
- try {
- int bitSize = params.getOrder().bitLength();
- // Hash the data.
- byte[] hash;
- if (hashAlgo == null || hashAlgo.equals("NONE")) {
- hash = data;
- } else {
- MessageDigest md = MessageDigest.getInstance(hashAlgo);
- hash = md.digest(data);
- }
- // Trim bitSize of rightmost bits.
- BigInteger hashInt = new BigInteger(1, hash);
- int hashBits = hashInt.bitLength();
- if (hashBits > bitSize) {
- hashInt = hashInt.shiftRight(hashBits - bitSize);
- }
-
- // Parse signature
- BigInteger[] sigPair;
- if (sigType.contains("CVC") || sigType.contains("PLAIN")) {
- sigPair = PlainDSAEncoding.INSTANCE.decode(params.getOrder(), signature);
- } else {
- sigPair = StandardDSAEncoding.INSTANCE.decode(params.getOrder(), signature);
- }
- BigInteger r = sigPair[0];
- BigInteger s = sigPair[1];
-
- BigInteger rd = privkey.multiply(r).mod(params.getOrder());
- BigInteger hrd = hashInt.add(rd).mod(params.getOrder());
- return s.modInverse(params.getOrder()).multiply(hrd).mod(params.getOrder());
- } catch (NoSuchAlgorithmException | IOException | ArithmeticException ex) {
- ex.printStackTrace();
- return null;
- }
- }
-
- public static EC_Params joinParams(EC_Params... params) {
- List<EC_Params> paramList = new LinkedList<>();
- short paramMask = 0;
- int len = 0;
- for (EC_Params param : params) {
- if (param == null) {
- continue;
- }
- int i = 0;
- for (; i + 1 < paramList.size(); ++i) {
- if (paramList.get(i + 1).getParams() == param.getParams()) {
- throw new IllegalArgumentException();
- }
- if (paramList.get(i + 1).getParams() < param.getParams()) {
- break;
- }
- }
- paramList.add(i, param);
- paramMask |= param.getParams();
- len += param.numParams();
- }
-
- byte[][] res = new byte[len][];
- int i = 0;
- for (EC_Params param : params) {
- for (byte[] data : param.getData()) {
- res[i++] = data.clone();
- }
- }
- return new EC_Params(paramMask, res);
- }
-
- public static EC_Params loadParams(short params, String named, String file) throws IOException {
- EC_Params result = null;
- if (file != null) {
- result = new EC_Params(params);
-
- FileInputStream in = new FileInputStream(file);
- result.readCSV(in);
- in.close();
- } else if (named != null) {
- if (params == EC_Consts.PARAMETER_W) {
- result = EC_Store.getInstance().getObject(EC_Key.Public.class, named);
- } else if (params == EC_Consts.PARAMETER_S) {
- result = EC_Store.getInstance().getObject(EC_Key.Private.class, named);
- }
-
- if (result == null) {
- result = EC_Store.getInstance().getObject(EC_Keypair.class, named);
- }
- }
- return result;
- }
-
- public static ECKey loadKey(short params, String named, String file, AlgorithmParameterSpec spec) throws IOException {
- if (params == EC_Consts.PARAMETERS_KEYPAIR) {
- throw new IllegalArgumentException();
- }
- EC_Params param = loadParams(params, named, file);
- if (param != null) {
- if (params == EC_Consts.PARAMETER_W) {
- return new RawECPublicKey(toPoint(param), (ECParameterSpec) spec);
- } else if (params == EC_Consts.PARAMETER_S) {
- return new RawECPrivateKey(toScalar(param), (ECParameterSpec) spec);
- }
- }
- return null;
- }
-
- public static boolean equalKeyPairParameters(ECPrivateKey priv, ECPublicKey pub) {
- if(priv == null || pub == null) {
- return false;
- }
- return priv.getParams().getCurve().equals(pub.getParams().getCurve()) &&
- priv.getParams().getCofactor() == pub.getParams().getCofactor() &&
- priv.getParams().getGenerator().equals(pub.getParams().getGenerator()) &&
- priv.getParams().getOrder().equals(pub.getParams().getOrder());
- }
-}
generated by cgit v1.2.3-70-g09d2 (git 2.52.0) at 2026-01-03 11:53:00 +0000