org.bitcoinj.crypto.ECKey Maven / Gradle / Ivy
/*
* Copyright 2011 Google Inc.
* Copyright 2014 Andreas Schildbach
* Copyright 2014-2016 the libsecp256k1 contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.bitcoinj.crypto;
import com.google.common.base.MoreObjects;
import org.bitcoin.NativeSecp256k1;
import org.bitcoin.NativeSecp256k1Util;
import org.bitcoin.Secp256k1Context;
import org.bitcoinj.base.Address;
import org.bitcoinj.base.BitcoinNetwork;
import org.bitcoinj.base.LegacyAddress;
import org.bitcoinj.base.Network;
import org.bitcoinj.base.ScriptType;
import org.bitcoinj.base.SegwitAddress;
import org.bitcoinj.base.Sha256Hash;
import org.bitcoinj.base.internal.TimeUtils;
import org.bitcoinj.base.internal.ByteUtils;
import org.bitcoinj.core.NetworkParameters;
import org.bitcoinj.base.VarInt;
import org.bitcoinj.crypto.internal.CryptoUtils;
import org.bitcoinj.crypto.utils.MessageVerifyUtils;
import org.bitcoinj.wallet.Protos;
import org.bitcoinj.wallet.Wallet;
import org.bouncycastle.asn1.ASN1InputStream;
import org.bouncycastle.asn1.ASN1Integer;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.BERTags;
import org.bouncycastle.asn1.DERBitString;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.DERSequenceGenerator;
import org.bouncycastle.asn1.DERTaggedObject;
import org.bouncycastle.asn1.DLSequence;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.asn1.x9.X9IntegerConverter;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.ec.CustomNamedCurves;
import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.signers.ECDSASigner;
import org.bouncycastle.crypto.signers.HMacDSAKCalculator;
import org.bouncycastle.math.ec.ECAlgorithms;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.math.ec.FixedPointCombMultiplier;
import org.bouncycastle.math.ec.FixedPointUtil;
import org.bouncycastle.math.ec.custom.sec.SecP256K1Curve;
import org.bouncycastle.util.Properties;
import org.bouncycastle.util.encoders.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.annotation.Nullable;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.nio.charset.StandardCharsets;
import java.security.SecureRandom;
import java.security.SignatureException;
import java.time.Instant;
import java.time.temporal.ChronoUnit;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Objects;
import java.util.Optional;
import static org.bitcoinj.base.internal.Preconditions.checkArgument;
import static org.bitcoinj.base.internal.Preconditions.checkState;
/**
* Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
* Creating a new ECKey with the empty constructor will generate a new random keypair. Other static methods can be used
* when you already have the public or private parts. If you create a key with only the public part, you can check
* signatures but not create them.
*
* ECKey also provides access to Bitcoin Core compatible text message signing, as accessible via the UI or JSON-RPC.
* This is slightly different to signing raw bytes - if you want to sign your own data and it won't be exposed as
* text to people, you don't want to use this. If in doubt, ask on the mailing list.
*
* The ECDSA algorithm supports key recovery in which a signature plus a couple of discriminator bits can
* be reversed to find the public key used to calculate it. This can be convenient when you have a message and a
* signature and want to find out who signed it, rather than requiring the user to provide the expected identity.
*
* This class supports a variety of serialization forms. The methods that accept/return byte arrays serialize
* private keys as raw byte arrays and public keys using the SEC standard byte encoding for public keys. Signatures
* are encoded using ASN.1/DER inside the Bitcoin protocol.
*
* A key can be compressed or uncompressed. This refers to whether the public key is represented
* when encoded into bytes as an (x, y) coordinate on the elliptic curve, or whether it's represented as just an X
* co-ordinate and an extra byte that carries a sign bit. With the latter form the Y coordinate can be calculated
* dynamically, however, because the binary serialization is different the address of a key changes if its
* compression status is changed. If you deviate from the defaults it's important to understand this: money sent
* to a compressed version of the key will have a different address to the same key in uncompressed form. Whether
* a public key is compressed or not is recorded in the SEC binary serialisation format, and preserved in a flag in
* this class so round-tripping preserves state. Unless you're working with old software or doing unusual things, you
* can usually ignore the compressed/uncompressed distinction.
*/
public class ECKey implements EncryptableItem {
private static final Logger log = LoggerFactory.getLogger(ECKey.class);
// Note: this can be replaced with Arrays.compareUnsigned(a, b) once we require Java 9
private static final Comparator LEXICOGRAPHICAL_COMPARATOR = ByteUtils.arrayUnsignedComparator();
/** Sorts oldest keys first, newest last. */
public static final Comparator AGE_COMPARATOR = Comparator.comparing(ecKey -> ecKey.creationTime().orElse(Instant.EPOCH));
/** Compares by extracting pub key as a {@code byte[]} and using a lexicographic comparator */
public static final Comparator PUBKEY_COMPARATOR = Comparator.comparing(ECKey::getPubKey, LEXICOGRAPHICAL_COMPARATOR);
// The parameters of the secp256k1 curve that Bitcoin uses.
private static final X9ECParameters CURVE_PARAMS = CustomNamedCurves.getByName("secp256k1");
/** The parameters of the secp256k1 curve that Bitcoin uses. */
public static final ECDomainParameters CURVE;
/**
* Equal to CURVE.getN().shiftRight(1), used for canonicalising the S value of a signature. If you aren't
* sure what this is about, you can ignore it.
*/
public static final BigInteger HALF_CURVE_ORDER;
private static final SecureRandom secureRandom;
static {
// Tell Bouncy Castle to precompute data that's needed during secp256k1 calculations.
FixedPointUtil.precompute(CURVE_PARAMS.getG());
CURVE = new ECDomainParameters(CURVE_PARAMS.getCurve(), CURVE_PARAMS.getG(), CURVE_PARAMS.getN(),
CURVE_PARAMS.getH());
HALF_CURVE_ORDER = CURVE_PARAMS.getN().shiftRight(1);
secureRandom = new SecureRandom();
}
// The two parts of the key. If "pub" is set but not "priv", we can only verify signatures, not make them.
@Nullable protected final BigInteger priv; // A field element.
protected final LazyECPoint pub;
// Creation time of the key, or null if the key was deserialized from a version that did
// not have this field.
@Nullable protected Instant creationTime = null;
protected KeyCrypter keyCrypter;
protected EncryptedData encryptedPrivateKey;
private byte[] pubKeyHash;
/**
* Generates an entirely new keypair. Point compression is used so the resulting public key will be 33 bytes
* (32 for the co-ordinate and 1 byte to represent the y bit).
*/
public ECKey() {
this(secureRandom);
}
/**
* Generates an entirely new keypair with the given {@link SecureRandom} object. Point compression is used so the
* resulting public key will be 33 bytes (32 for the co-ordinate and 1 byte to represent the y bit).
*/
public ECKey(SecureRandom secureRandom) {
ECKeyPairGenerator generator = new ECKeyPairGenerator();
ECKeyGenerationParameters keygenParams = new ECKeyGenerationParameters(CURVE, secureRandom);
generator.init(keygenParams);
AsymmetricCipherKeyPair keypair = generator.generateKeyPair();
ECPrivateKeyParameters privParams = (ECPrivateKeyParameters) keypair.getPrivate();
ECPublicKeyParameters pubParams = (ECPublicKeyParameters) keypair.getPublic();
priv = privParams.getD();
pub = new LazyECPoint(pubParams.getQ(), true);
creationTime = TimeUtils.currentTime().truncatedTo(ChronoUnit.SECONDS);
}
protected ECKey(@Nullable BigInteger priv, ECPoint pub, boolean compressed) {
this(priv, new LazyECPoint(Objects.requireNonNull(pub), compressed));
}
protected ECKey(@Nullable BigInteger priv, LazyECPoint pub) {
if (priv != null) {
checkArgument(priv.bitLength() <= 32 * 8, () ->
"private key exceeds 32 bytes: " + priv.bitLength() + " bits");
// Try and catch buggy callers or bad key imports, etc. Zero and one are special because these are often
// used as sentinel values and because scripting languages have a habit of auto-casting true and false to
// 1 and 0 or vice-versa. Type confusion bugs could therefore result in private keys with these values.
checkArgument(!priv.equals(BigInteger.ZERO));
checkArgument(!priv.equals(BigInteger.ONE));
}
this.priv = priv;
this.pub = Objects.requireNonNull(pub);
}
/**
* Construct an ECKey from an ASN.1 encoded private key. These are produced by OpenSSL and stored by Bitcoin
* Core in its wallet. Note that this is slow because it requires an EC point multiply.
*/
public static ECKey fromASN1(byte[] asn1privkey) {
return extractKeyFromASN1(asn1privkey);
}
/**
* Creates an ECKey given the private key only. The public key is calculated from it (this is slow). The resulting
* public key is compressed.
*/
public static ECKey fromPrivate(BigInteger privKey) {
return fromPrivate(privKey, true);
}
/**
* Creates an ECKey given the private key only. The public key is calculated from it (this is slow).
* @param compressed Determines whether the resulting ECKey will use a compressed encoding for the public key.
*/
public static ECKey fromPrivate(BigInteger privKey, boolean compressed) {
ECPoint point = publicPointFromPrivate(privKey);
return new ECKey(privKey, new LazyECPoint(point, compressed));
}
/**
* Creates an ECKey given the private key only. The public key is calculated from it (this is slow). The resulting
* public key is compressed.
*/
public static ECKey fromPrivate(byte[] privKeyBytes) {
return fromPrivate(ByteUtils.bytesToBigInteger(privKeyBytes));
}
/**
* Creates an ECKey given the private key only. The public key is calculated from it (this is slow).
* @param compressed Determines whether the resulting ECKey will use a compressed encoding for the public key.
*/
public static ECKey fromPrivate(byte[] privKeyBytes, boolean compressed) {
return fromPrivate(ByteUtils.bytesToBigInteger(privKeyBytes), compressed);
}
/**
* Creates an ECKey that simply trusts the caller to ensure that point is really the result of multiplying the
* generator point by the private key. This is used to speed things up when you know you have the right values
* already.
* @param compressed Determines whether the resulting ECKey will use a compressed encoding for the public key.
*/
public static ECKey fromPrivateAndPrecalculatedPublic(BigInteger priv, ECPoint pub, boolean compressed) {
return new ECKey(priv, pub, compressed);
}
/**
* Creates an ECKey that simply trusts the caller to ensure that point is really the result of multiplying the
* generator point by the private key. This is used to speed things up when you know you have the right values
* already. The compression state of the point will be preserved.
*/
public static ECKey fromPrivateAndPrecalculatedPublic(byte[] priv, byte[] pub) {
Objects.requireNonNull(priv);
Objects.requireNonNull(pub);
return new ECKey(ByteUtils.bytesToBigInteger(priv), new LazyECPoint(CURVE.getCurve(), pub));
}
/**
* Creates an ECKey that cannot be used for signing, only verifying signatures, from the given point.
* @param compressed Determines whether the resulting ECKey will use a compressed encoding for the public key.
*/
public static ECKey fromPublicOnly(ECPoint pub, boolean compressed) {
return new ECKey(null, pub, compressed);
}
/**
* Creates an ECKey that cannot be used for signing, only verifying signatures, from the given encoded point.
* The compression state of pub will be preserved.
*/
public static ECKey fromPublicOnly(byte[] pub) {
return new ECKey(null, new LazyECPoint(CURVE.getCurve(), pub));
}
public static ECKey fromPublicOnly(ECKey key) {
return fromPublicOnly(key.getPubKeyPoint(), key.isCompressed());
}
/**
* Returns a copy of this key, but with the public point represented in uncompressed form. Normally you would
* never need this: it's for specialised scenarios or when backwards compatibility in encoded form is necessary.
*/
public ECKey decompress() {
if (!pub.isCompressed())
return this;
else
return new ECKey(priv, new LazyECPoint(pub.get(), false));
}
/**
* Constructs a key that has an encrypted private component. The given object wraps encrypted bytes and an
* initialization vector. Note that the key will not be decrypted during this call: the returned ECKey is
* unusable for signing unless a decryption key is supplied.
*/
public static ECKey fromEncrypted(EncryptedData encryptedPrivateKey, KeyCrypter crypter, byte[] pubKey) {
ECKey key = fromPublicOnly(pubKey);
key.encryptedPrivateKey = Objects.requireNonNull(encryptedPrivateKey);
key.keyCrypter = Objects.requireNonNull(crypter);
return key;
}
/**
* Returns true if this key doesn't have unencrypted access to private key bytes. This may be because it was never
* given any private key bytes to begin with (a watching key), or because the key is encrypted. You can use
* {@link #isEncrypted()} to tell the cases apart.
*/
public boolean isPubKeyOnly() {
return priv == null;
}
/**
* Returns true if this key has unencrypted access to private key bytes. Does the opposite of
* {@link #isPubKeyOnly()}.
*/
public boolean hasPrivKey() {
return priv != null;
}
/** Returns true if this key is watch only, meaning it has a public key but no private key. */
public boolean isWatching() {
return isPubKeyOnly() && !isEncrypted();
}
/**
* Output this ECKey as an ASN.1 encoded private key, as understood by OpenSSL or used by Bitcoin Core
* in its wallet storage format.
* @throws ECKey.MissingPrivateKeyException if the private key is missing or encrypted.
*/
public byte[] toASN1() {
try {
byte[] privKeyBytes = getPrivKeyBytes();
ByteArrayOutputStream baos = new ByteArrayOutputStream(400);
// ASN1_SEQUENCE(EC_PRIVATEKEY) = {
// ASN1_SIMPLE(EC_PRIVATEKEY, version, LONG),
// ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
// ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
// ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1)
// } ASN1_SEQUENCE_END(EC_PRIVATEKEY)
DERSequenceGenerator seq = new DERSequenceGenerator(baos);
seq.addObject(new ASN1Integer(1)); // version
seq.addObject(new DEROctetString(privKeyBytes));
seq.addObject(new DERTaggedObject(0, CURVE_PARAMS.toASN1Primitive()));
seq.addObject(new DERTaggedObject(1, new DERBitString(getPubKey())));
seq.close();
return baos.toByteArray();
} catch (IOException e) {
throw new RuntimeException(e); // Cannot happen, writing to memory stream.
}
}
/**
* Returns public key bytes from the given private key. To convert a byte array into a BigInteger,
* use {@link ByteUtils#bytesToBigInteger(byte[])}
*/
public static byte[] publicKeyFromPrivate(BigInteger privKey, boolean compressed) {
ECPoint point = publicPointFromPrivate(privKey);
return point.getEncoded(compressed);
}
/**
* Returns public key point from the given private key. To convert a byte array into a BigInteger,
* use {@link ByteUtils#bytesToBigInteger(byte[])}
*/
public static ECPoint publicPointFromPrivate(BigInteger privKey) {
/*
* TODO: FixedPointCombMultiplier currently doesn't support scalars longer than the group order,
* but that could change in future versions.
*/
if (privKey.bitLength() > CURVE.getN().bitLength()) {
privKey = privKey.mod(CURVE.getN());
}
return new FixedPointCombMultiplier().multiply(CURVE.getG(), privKey);
}
/** Gets the hash160 form of the public key (as seen in addresses). */
public byte[] getPubKeyHash() {
if (pubKeyHash == null)
pubKeyHash = CryptoUtils.sha256hash160(this.pub.getEncoded());
return pubKeyHash;
}
/**
* Gets the raw public key value. This appears in transaction scriptSigs. Note that this is not the same
* as the pubKeyHash/address.
*/
public byte[] getPubKey() {
return pub.getEncoded();
}
/** Gets the public key in the form of an elliptic curve point object from Bouncy Castle. */
public ECPoint getPubKeyPoint() {
return pub.get();
}
/**
* Gets the private key in the form of an integer field element. The public key is derived by performing EC
* point addition this number of times (i.e. point multiplying).
*
* @throws java.lang.IllegalStateException if the private key bytes are not available.
*/
public BigInteger getPrivKey() {
if (priv == null)
throw new MissingPrivateKeyException();
return priv;
}
/**
* Returns whether this key is using the compressed form or not. Compressed pubkeys are only 33 bytes, not 64.
*/
public boolean isCompressed() {
return pub.isCompressed();
}
public Address toAddress(ScriptType scriptType, Network network) {
if (scriptType == ScriptType.P2PKH) {
return LegacyAddress.fromPubKeyHash(network, this.getPubKeyHash());
} else if (scriptType == ScriptType.P2WPKH) {
checkArgument(this.isCompressed(), () ->
"only compressed keys allowed");
return SegwitAddress.fromHash(network, this.getPubKeyHash());
} else {
throw new IllegalArgumentException(scriptType.toString());
}
}
/**
* Groups the two components that make up a signature, and provides a way to encode to DER form, which is
* how ECDSA signatures are represented when embedded in other data structures in the Bitcoin protocol. The raw
* components can be useful for doing further EC maths on them.
*/
public static class ECDSASignature {
/** The two components of the signature. */
public final BigInteger r, s;
/**
* Constructs a signature with the given components. Does NOT automatically canonicalise the signature.
*/
public ECDSASignature(BigInteger r, BigInteger s) {
this.r = r;
this.s = s;
}
/**
* Returns true if the S component is "low", that means it is below {@link ECKey#HALF_CURVE_ORDER}. See BIP62.
*/
public boolean isCanonical() {
return s.compareTo(HALF_CURVE_ORDER) <= 0;
}
/**
* Will automatically adjust the S component to be less than or equal to half the curve order, if necessary.
* This is required because for every signature (r,s) the signature (r, -s (mod N)) is a valid signature of
* the same message. However, we dislike the ability to modify the bits of a Bitcoin transaction after it's
* been signed, as that violates various assumed invariants. Thus in future only one of those forms will be
* considered legal and the other will be banned.
*/
public ECDSASignature toCanonicalised() {
if (!isCanonical()) {
// The order of the curve is the number of valid points that exist on that curve. If S is in the upper
// half of the number of valid points, then bring it back to the lower half. Otherwise, imagine that
// N = 10
// s = 8, so (-8 % 10 == 2) thus both (r, 8) and (r, 2) are valid solutions.
// 10 - 8 == 2, giving us always the latter solution, which is canonical.
return new ECDSASignature(r, CURVE.getN().subtract(s));
} else {
return this;
}
}
/**
* DER is an international standard for serializing data structures which is widely used in cryptography.
* It's somewhat like protocol buffers but less convenient. This method returns a standard DER encoding
* of the signature, as recognized by OpenSSL and other libraries.
*/
public byte[] encodeToDER() {
try {
return derByteStream().toByteArray();
} catch (IOException e) {
throw new RuntimeException(e); // Cannot happen.
}
}
/**
* @throws SignatureDecodeException if the signature is unparseable in some way.
*/
public static ECDSASignature decodeFromDER(byte[] bytes) throws SignatureDecodeException {
ASN1InputStream decoder = null;
try {
// BouncyCastle by default is strict about parsing ASN.1 integers. We relax this check, because some
// Bitcoin signatures would not parse.
Properties.setThreadOverride("org.bouncycastle.asn1.allow_unsafe_integer", true);
decoder = new ASN1InputStream(bytes);
final ASN1Primitive seqObj = decoder.readObject();
if (seqObj == null)
throw new SignatureDecodeException("Reached past end of ASN.1 stream.");
if (!(seqObj instanceof DLSequence))
throw new SignatureDecodeException("Read unexpected class: " + seqObj.getClass().getName());
final DLSequence seq = (DLSequence) seqObj;
ASN1Integer r, s;
try {
r = (ASN1Integer) seq.getObjectAt(0);
s = (ASN1Integer) seq.getObjectAt(1);
} catch (ClassCastException e) {
throw new SignatureDecodeException(e);
}
// OpenSSL deviates from the DER spec by interpreting these values as unsigned, though they should not be
// Thus, we always use the positive versions. See: http://r6.ca/blog/20111119T211504Z.html
return new ECDSASignature(r.getPositiveValue(), s.getPositiveValue());
} catch (IOException e) {
throw new SignatureDecodeException(e);
} finally {
if (decoder != null)
try { decoder.close(); } catch (IOException x) {}
Properties.removeThreadOverride("org.bouncycastle.asn1.allow_unsafe_integer");
}
}
protected ByteArrayOutputStream derByteStream() throws IOException {
// Usually 70-72 bytes.
ByteArrayOutputStream bos = new ByteArrayOutputStream(72);
DERSequenceGenerator seq = new DERSequenceGenerator(bos);
seq.addObject(new ASN1Integer(r));
seq.addObject(new ASN1Integer(s));
seq.close();
return bos;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ECDSASignature other = (ECDSASignature) o;
return r.equals(other.r) && s.equals(other.s);
}
@Override
public int hashCode() {
return Objects.hash(r, s);
}
}
/**
* Signs the given hash and returns the R and S components as BigIntegers. In the Bitcoin protocol, they are
* usually encoded using ASN.1 format, so you want {@link ECKey.ECDSASignature#toASN1()}
* instead. However sometimes the independent components can be useful, for instance, if you're going to do
* further EC maths on them.
* @throws KeyCrypterException if this ECKey doesn't have a private part.
*/
public ECDSASignature sign(Sha256Hash input) throws KeyCrypterException {
return sign(input, null);
}
/**
* Signs the given hash and returns the R and S components as BigIntegers. In the Bitcoin protocol, they are
* usually encoded using DER format, so you want {@link ECKey.ECDSASignature#encodeToDER()}
* instead. However sometimes the independent components can be useful, for instance, if you're doing to do further
* EC maths on them.
*
* @param aesKey The AES key to use for decryption of the private key. If null then no decryption is required.
* @throws KeyCrypterException if there's something wrong with aesKey.
* @throws ECKey.MissingPrivateKeyException if this key cannot sign because it's pubkey only.
*/
public ECDSASignature sign(Sha256Hash input, @Nullable AesKey aesKey) throws KeyCrypterException {
KeyCrypter crypter = getKeyCrypter();
if (crypter != null) {
if (aesKey == null)
throw new KeyIsEncryptedException();
return decrypt(aesKey).sign(input);
} else {
// No decryption of private key required.
if (priv == null)
throw new MissingPrivateKeyException();
}
return doSign(input, priv);
}
protected ECDSASignature doSign(Sha256Hash input, BigInteger privateKeyForSigning) {
if (Secp256k1Context.isEnabled()) {
try {
byte[] signature = NativeSecp256k1.sign(
input.getBytes(),
ByteUtils.bigIntegerToBytes(privateKeyForSigning, 32)
);
return ECDSASignature.decodeFromDER(signature);
} catch (NativeSecp256k1Util.AssertFailException e) {
log.error("Caught AssertFailException inside secp256k1", e);
throw new RuntimeException(e);
} catch (SignatureDecodeException e) {
throw new RuntimeException(e); // cannot happen
}
}
Objects.requireNonNull(privateKeyForSigning);
ECDSASigner signer = new ECDSASigner(new HMacDSAKCalculator(new SHA256Digest()));
ECPrivateKeyParameters privKey = new ECPrivateKeyParameters(privateKeyForSigning, CURVE);
signer.init(true, privKey);
BigInteger[] components = signer.generateSignature(input.getBytes());
return new ECDSASignature(components[0], components[1]).toCanonicalised();
}
/**
* Verifies the given ECDSA signature against the message bytes using the public key bytes.
*
* When using native ECDSA verification, data must be 32 bytes, and no element may be
* larger than 520 bytes.
*
* @param data Hash of the data to verify.
* @param signature ASN.1 encoded signature.
* @param pub The public key bytes to use.
*/
public static boolean verify(byte[] data, ECDSASignature signature, byte[] pub) {
if (Secp256k1Context.isEnabled()) {
try {
return NativeSecp256k1.verify(data, signature.encodeToDER(), pub);
} catch (NativeSecp256k1Util.AssertFailException e) {
log.error("Caught AssertFailException inside secp256k1", e);
return false;
}
}
ECDSASigner signer = new ECDSASigner();
ECPublicKeyParameters params = new ECPublicKeyParameters(CURVE.getCurve().decodePoint(pub), CURVE);
signer.init(false, params);
try {
return signer.verifySignature(data, signature.r, signature.s);
} catch (NullPointerException e) {
// Bouncy Castle contains a bug that can cause NPEs given specially crafted signatures. Those signatures
// are inherently invalid/attack sigs so we just fail them here rather than crash the thread.
log.error("Caught NPE inside bouncy castle", e);
return false;
}
}
/**
* Verifies the given ASN.1 encoded ECDSA signature against a hash using the public key.
*
* @param data Hash of the data to verify.
* @param signature ASN.1 encoded signature.
* @param pub The public key bytes to use.
* @throws SignatureDecodeException if the signature is unparseable in some way.
*/
public static boolean verify(byte[] data, byte[] signature, byte[] pub) throws SignatureDecodeException {
if (Secp256k1Context.isEnabled()) {
try {
return NativeSecp256k1.verify(data, signature, pub);
} catch (NativeSecp256k1Util.AssertFailException e) {
log.error("Caught AssertFailException inside secp256k1", e);
return false;
}
}
return verify(data, ECDSASignature.decodeFromDER(signature), pub);
}
/**
* Verifies the given ASN.1 encoded ECDSA signature against a hash using the public key.
*
* @param hash Hash of the data to verify.
* @param signature ASN.1 encoded signature.
* @throws SignatureDecodeException if the signature is unparseable in some way.
*/
public boolean verify(byte[] hash, byte[] signature) throws SignatureDecodeException {
return ECKey.verify(hash, signature, getPubKey());
}
/**
* Verifies the given R/S pair (signature) against a hash using the public key.
*/
public boolean verify(Sha256Hash sigHash, ECDSASignature signature) {
return ECKey.verify(sigHash.getBytes(), signature, getPubKey());
}
/**
* Verifies the given ASN.1 encoded ECDSA signature against a hash using the public key, and throws an exception
* if the signature doesn't match
* @throws SignatureDecodeException if the signature is unparseable in some way.
* @throws java.security.SignatureException if the signature does not match.
*/
public void verifyOrThrow(byte[] hash, byte[] signature) throws SignatureDecodeException, SignatureException {
if (!verify(hash, signature))
throw new SignatureException();
}
/**
* Verifies the given R/S pair (signature) against a hash using the public key, and throws an exception
* if the signature doesn't match
* @throws java.security.SignatureException if the signature does not match.
*/
public void verifyOrThrow(Sha256Hash sigHash, ECDSASignature signature) throws SignatureException {
if (!ECKey.verify(sigHash.getBytes(), signature, getPubKey()))
throw new SignatureException();
}
/**
* Returns true if the given pubkey is canonical, i.e. the correct length taking into account compression.
*/
public static boolean isPubKeyCanonical(byte[] pubkey) {
if (pubkey.length < 33)
return false;
if (pubkey[0] == 0x04) {
// Uncompressed pubkey
if (pubkey.length != 65)
return false;
} else if (pubkey[0] == 0x02 || pubkey[0] == 0x03) {
// Compressed pubkey
if (pubkey.length != 33)
return false;
} else
return false;
return true;
}
/**
* Returns true if the given pubkey is in its compressed form.
*/
public static boolean isPubKeyCompressed(byte[] encoded) {
if (encoded.length == 33 && (encoded[0] == 0x02 || encoded[0] == 0x03))
return true;
else if (encoded.length == 65 && encoded[0] == 0x04)
return false;
else
throw new IllegalArgumentException(ByteUtils.formatHex(encoded));
}
private static ECKey extractKeyFromASN1(byte[] asn1privkey) {
// To understand this code, see the definition of the ASN.1 format for EC private keys in the OpenSSL source
// code in ec_asn1.c:
//
// ASN1_SEQUENCE(EC_PRIVATEKEY) = {
// ASN1_SIMPLE(EC_PRIVATEKEY, version, LONG),
// ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
// ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
// ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1)
// } ASN1_SEQUENCE_END(EC_PRIVATEKEY)
//
try {
ASN1InputStream decoder = new ASN1InputStream(asn1privkey);
DLSequence seq = (DLSequence) decoder.readObject();
checkArgument(decoder.readObject() == null, () ->
"input contains extra bytes");
decoder.close();
checkArgument(seq.size() == 4, () ->
"input does not appear to be an ASN.1 OpenSSL EC private key");
checkArgument(((ASN1Integer) seq.getObjectAt(0)).getValue().equals(BigInteger.ONE), () ->
"input is of wrong version");
byte[] privbits = ((ASN1OctetString) seq.getObjectAt(1)).getOctets();
BigInteger privkey = ByteUtils.bytesToBigInteger(privbits);
ASN1TaggedObject pubkey = (ASN1TaggedObject) seq.getObjectAt(3);
checkArgument(pubkey.getTagNo() == 1, () ->
"input has 'publicKey' with bad tag number");
checkArgument(pubkey.getTagClass() == BERTags.CONTEXT_SPECIFIC, () ->
"input has 'publicKey' with bad tag class");
byte[] pubbits = ((DERBitString) pubkey.getBaseObject()).getBytes();
checkArgument(pubbits.length == 33 || pubbits.length == 65, () ->
"input has 'publicKey' with invalid length");
int encoding = pubbits[0] & 0xFF;
// Only allow compressed(2,3) and uncompressed(4), not infinity(0) or hybrid(6,7)
checkArgument(encoding >= 2 && encoding <= 4, () ->
"input has 'publicKey' with invalid encoding");
// Now sanity check to ensure the pubkey bytes match the privkey.
ECKey key = ECKey.fromPrivate(privkey, isPubKeyCompressed(pubbits));
checkArgument (Arrays.equals(key.getPubKey(), pubbits), () ->
"public key in ASN.1 structure does not match private key.");
return key;
} catch (IOException e) {
throw new RuntimeException(e); // Cannot happen, reading from memory stream.
}
}
/**
* Signs a text message using the standard Bitcoin messaging signing format and returns the signature as a base64
* encoded string.
*
* @throws IllegalStateException if this ECKey does not have the private part.
* @throws KeyCrypterException if this ECKey is encrypted and no AESKey is provided or it does not decrypt the ECKey.
* @deprecated use {@link #signMessage(String, ScriptType)} instead and specify the correct script type
*/
@Deprecated
public String signMessage(String message) throws KeyCrypterException {
return signMessage(message, null, ScriptType.P2PKH);
}
/**
* Signs a text message using the standard Bitcoin messaging signing format and returns the signature as a base64
* encoded string.
*
* @throws IllegalStateException if this ECKey does not have the private part.
* @throws KeyCrypterException if this ECKey is encrypted and no AESKey is provided or it does not decrypt the ECKey.
*/
public String signMessage(String message, ScriptType scriptType) throws KeyCrypterException {
return signMessage(message, null, scriptType);
}
/**
* Signs a text message using the standard Bitcoin messaging signing format and returns the signature as a base64
* encoded string.
*
* @throws IllegalStateException if this ECKey does not have the private part.
* @throws KeyCrypterException if this ECKey is encrypted and no AESKey is provided or it does not decrypt the ECKey.
* @deprecated use {@link #signMessage(String, AesKey, ScriptType)} instead and specify the correct script type
*/
@Deprecated
public String signMessage(String message, @Nullable AesKey aesKey) throws KeyCrypterException {
return signMessage(message, aesKey, ScriptType.P2PKH);
}
/**
* Signs a text message using the standard Bitcoin messaging signing format and returns the signature as a base64
* encoded string.
*
* @throws IllegalArgumentException if uncompressed key is used for Segwit scriptType, or unsupported script type is specified
* @throws IllegalStateException if this ECKey does not have the private part.
* @throws KeyCrypterException if this ECKey is encrypted and no AESKey is provided or it does not decrypt the ECKey.
*/
public String signMessage(String message, @Nullable AesKey aesKey, ScriptType scriptType) throws KeyCrypterException {
if (!isCompressed() && (scriptType == ScriptType.P2WPKH || scriptType == ScriptType.P2SH)) {
throw new IllegalArgumentException("Segwit P2WPKH and P2SH-P2WPKH script types only can be used with compressed keys. See BIP 141.");
}
byte[] data = formatMessageForSigning(message);
Sha256Hash hash = Sha256Hash.twiceOf(data);
ECDSASignature sig = sign(hash, aesKey);
byte recId = findRecoveryId(hash, sig);
// Meaning of header byte ranges:
// * 27-30: P2PKH uncompressed, recId 0-3
// * 31-34: P2PKH compressed, recId 0-3
// * 35-38: Segwit P2SH (always compressed), recId 0-3
// * 39-42: Segwit Bech32 (always compressed), recId 0-3
// as defined in https://github.com/bitcoin/bips/blob/master/bip-0137.mediawiki#procedure-for-signingverifying-a-signature
int headerByte;
switch (scriptType) {
case P2PKH:
headerByte = recId + 27 + (isCompressed() ? 4 : 0);
break;
case P2SH: // P2SH-P2WPKH ("legacy-segwit")
headerByte = recId + 35;
break;
case P2WPKH:
headerByte = recId + 39;
break;
default:
throw new IllegalArgumentException("Unsupported script type for message signing.");
}
byte[] sigData = new byte[65]; // 1 header + 32 bytes for R + 32 bytes for S
sigData[0] = (byte)headerByte;
System.arraycopy(ByteUtils.bigIntegerToBytes(sig.r, 32), 0, sigData, 1, 32);
System.arraycopy(ByteUtils.bigIntegerToBytes(sig.s, 32), 0, sigData, 33, 32);
return new String(Base64.encode(sigData), StandardCharsets.UTF_8);
}
/**
* Given an arbitrary piece of text and a Bitcoin-format message signature encoded in base64, returns an ECKey
* containing the public key that was used to sign it. This can then be compared to the expected public key to
* determine if the signature was correct. These sorts of signatures are compatible with the Bitcoin-Qt/bitcoind
* format generated by signmessage/verifymessage RPCs and GUI menu options. They are intended for humans to verify
* their communications with each other, hence the base64 format and the fact that the input is text.
*
* @param message Some piece of human readable text.
* @param signatureBase64 The Bitcoin-format message signature in base64
* @throws SignatureException If the public key could not be recovered or if there was a signature format error.
*/
public static ECKey signedMessageToKey(String message, String signatureBase64) throws SignatureException {
byte[] signatureEncoded;
try {
signatureEncoded = Base64.decode(signatureBase64);
} catch (RuntimeException e) {
// This is what you get back from Bouncy Castle if base64 doesn't decode :(
throw new SignatureException("Could not decode base64", e);
}
// Parse the signature bytes into r/s and the selector value.
if (signatureEncoded.length < 65)
throw new SignatureException("Signature truncated, expected 65 bytes and got " + signatureEncoded.length);
int header = signatureEncoded[0] & 0xFF;
// allowed range of valid header byte values as defined in BIP 137:
if (header < 27 || header > 42)
throw new SignatureException("Header byte out of range: " + header);
BigInteger r = ByteUtils.bytesToBigInteger(Arrays.copyOfRange(signatureEncoded, 1, 33));
BigInteger s = ByteUtils.bytesToBigInteger(Arrays.copyOfRange(signatureEncoded, 33, 65));
ECDSASignature sig = new ECDSASignature(r, s);
byte[] messageBytes = formatMessageForSigning(message);
// Note that the C++ code doesn't actually seem to specify any character encoding. Presumably it's whatever
// JSON-SPIRIT hands back. Assume UTF-8 for now.
Sha256Hash messageHash = Sha256Hash.twiceOf(messageBytes);
boolean compressed = false;
// Meaning of header byte ranges:
// * 27-30: P2PKH uncompressed, recId 0-3
// * 31-34: P2PKH compressed, recId 0-3
// * 35-38: Segwit P2SH (always compressed), recId 0-3
// * 39-42: Segwit Bech32 (always compressed), recId 0-3
// as defined in https://github.com/bitcoin/bips/blob/master/bip-0137.mediawiki#procedure-for-signingverifying-a-signature
// this is a signature created with a Segwit bech32 address
if (header >= 39) {
header -= 12;
compressed = true; // by definition in BIP 141
}
// this is a signature created with a Segwit p2sh (p2sh-p2wpkh) address
else if (header >= 35) {
header -= 8;
compressed = true; // by definition in BIP 141
}
// this is a signature created with a compressed p2pkh address
else if (header >= 31) {
compressed = true;
header -= 4;
}
// else: signature created with an uncompressed p2pkh address
// As the recovery of a pubkey from an ECDSA signature will recover several possible
// public keys, the header byte is used to carry information, which of the possible
// keys was the key used to create the signature (see also BIP 137):
// header byte: 27 = first key with even y, 28 = first key with odd y,
// 29 = second key with even y, 30 = second key with odd y
int recId = header - 27;
ECKey key = ECKey.recoverFromSignature(recId, sig, messageHash, compressed);
if (key == null)
throw new SignatureException("Could not recover public key from signature");
return key;
}
/**
* Convenience wrapper around {@link ECKey#signedMessageToKey(String, String)}. If the key derived from the
* signature is not the same as this one, throws a SignatureException.
* @deprecated Use {@link MessageVerifyUtils#verifyMessage(Address, String, String)} instead,
* which works with different address types, which works also with legacy segwit (P2SH-P2WPKH, 3…)
* and native segwit addresses (P2WPKH, bc1…).
*/
@Deprecated
public void verifyMessage(String message, String signatureBase64) throws SignatureException {
ECKey key = ECKey.signedMessageToKey(message, signatureBase64);
if (!key.pub.equals(pub))
throw new SignatureException("Signature did not match for message");
}
/**
* Returns the recovery ID, a byte with value between 0 and 3, inclusive, that specifies which of 4 possible
* curve points was used to sign a message. This value is also referred to as "v".
*
* @throws RuntimeException if no recovery ID can be found.
*/
public byte findRecoveryId(Sha256Hash hash, ECDSASignature sig) {
byte recId = -1;
for (byte i = 0; i < 4; i++) {
ECKey k = ECKey.recoverFromSignature(i, sig, hash, isCompressed());
if (k != null && k.pub.equals(pub)) {
recId = i;
break;
}
}
if (recId == -1)
throw new RuntimeException("Could not construct a recoverable key. This should never happen.");
return recId;
}
/**
* Given the components of a signature and a selector value, recover and return the public key
* that generated the signature according to the algorithm in SEC1v2 section 4.1.6.
*
* The recId is an index from 0 to 3 which indicates which of the 4 possible keys is the correct one. Because
* the key recovery operation yields multiple potential keys, the correct key must either be stored alongside the
* signature, or you must be willing to try each recId in turn until you find one that outputs the key you are
* expecting.
*
* If this method returns null it means recovery was not possible and recId should be iterated.
*
* Given the above two points, a correct usage of this method is inside a for loop from 0 to 3, and if the
* output is null OR a key that is not the one you expect, you try again with the next recId.
*
* @param recId Which possible key to recover.
* @param sig the R and S components of the signature, wrapped.
* @param message Hash of the data that was signed.
* @param compressed Whether or not the original pubkey was compressed.
* @return An ECKey containing only the public part, or null if recovery wasn't possible.
*/
@Nullable
public static ECKey recoverFromSignature(int recId, ECDSASignature sig, Sha256Hash message, boolean compressed) {
checkArgument(recId >= 0, () -> "recId must be positive");
checkArgument(sig.r.signum() >= 0, () -> "r must be positive");
checkArgument(sig.s.signum() >= 0, () -> "s must be positive");
Objects.requireNonNull(message);
// see https://www.secg.org/sec1-v2.pdf, section 4.1.6
// 1.0 For j from 0 to h (h == recId here and the loop is outside this function)
// 1.1 Let x = r + jn
BigInteger n = CURVE.getN(); // Curve order.
BigInteger i = BigInteger.valueOf((long) recId / 2);
BigInteger x = sig.r.add(i.multiply(n));
// 1.2. Convert the integer x to an octet string X of length mlen using the conversion routine
// specified in Section 2.3.7, where mlen = ⌈(log2 p)/8⌉ or mlen = ⌈m/8⌉.
// 1.3. Convert the octet string (16 set binary digits)||X to an elliptic curve point R using the
// conversion routine specified in Section 2.3.4. If this conversion routine outputs "invalid", then
// do another iteration of Step 1.
//
// More concisely, what these points mean is to use X as a compressed public key.
BigInteger prime = SecP256K1Curve.q;
if (x.compareTo(prime) >= 0) {
// Cannot have point co-ordinates larger than this as everything takes place modulo Q.
return null;
}
// Compressed keys require you to know an extra bit of data about the y-coord as there are two possibilities.
// So it's encoded in the recId.
ECPoint R = decompressKey(x, (recId & 1) == 1);
// 1.4. If nR != point at infinity, then do another iteration of Step 1 (callers responsibility).
if (!R.multiply(n).isInfinity())
return null;
// 1.5. Compute e from M using Steps 2 and 3 of ECDSA signature verification.
BigInteger e = message.toBigInteger();
// 1.6. For k from 1 to 2 do the following. (loop is outside this function via iterating recId)
// 1.6.1. Compute a candidate public key as:
// Q = mi(r) * (sR - eG)
//
// Where mi(x) is the modular multiplicative inverse. We transform this into the following:
// Q = (mi(r) * s ** R) + (mi(r) * -e ** G)
// Where -e is the modular additive inverse of e, that is z such that z + e = 0 (mod n). In the above equation
// ** is point multiplication and + is point addition (the EC group operator).
//
// We can find the additive inverse by subtracting e from zero then taking the mod. For example the additive
// inverse of 3 modulo 11 is 8 because 3 + 8 mod 11 = 0, and -3 mod 11 = 8.
BigInteger eInv = BigInteger.ZERO.subtract(e).mod(n);
BigInteger rInv = sig.r.modInverse(n);
BigInteger srInv = rInv.multiply(sig.s).mod(n);
BigInteger eInvrInv = rInv.multiply(eInv).mod(n);
ECPoint q = ECAlgorithms.sumOfTwoMultiplies(CURVE.getG(), eInvrInv, R, srInv);
return ECKey.fromPublicOnly(q, compressed);
}
/** Decompress a compressed public key (x co-ord and low-bit of y-coord). */
private static ECPoint decompressKey(BigInteger xBN, boolean yBit) {
X9IntegerConverter x9 = new X9IntegerConverter();
byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(CURVE.getCurve()));
compEnc[0] = (byte)(yBit ? 0x03 : 0x02);
return CURVE.getCurve().decodePoint(compEnc);
}
/**
* Returns a 32 byte array containing the private key.
* @throws ECKey.MissingPrivateKeyException if the private key bytes are missing/encrypted.
*/
public byte[] getPrivKeyBytes() {
return ByteUtils.bigIntegerToBytes(getPrivKey(), 32);
}
/**
* Exports the private key in the form used by Bitcoin Core's "dumpprivkey" and "importprivkey" commands. Use
* the {@link DumpedPrivateKey#toString()} method to get the string.
*
* @param network The network this key is intended for use on.
* @return Private key bytes as a {@link DumpedPrivateKey}.
* @throws IllegalStateException if the private key is not available.
*/
public DumpedPrivateKey getPrivateKeyEncoded(Network network) {
return new DumpedPrivateKey(network, getPrivKeyBytes(), isCompressed());
}
/**
* Exports the private key in the form used by Bitcoin Core's "dumpprivkey" and "importprivkey" commands. Use
* the {@link DumpedPrivateKey#toString()} method to get the string.
*
* @param params The network this key is intended for use on.
* @return Private key bytes as a {@link DumpedPrivateKey}.
* @throws IllegalStateException if the private key is not available.
* @deprecated Use {@link #getPrivateKeyEncoded(Network)}
*/
@Deprecated
public DumpedPrivateKey getPrivateKeyEncoded(NetworkParameters params) {
return getPrivateKeyEncoded(params.network());
}
/**
* Returns the creation time of this key, or empty if the key was deserialized from a version that did not store
* that data.
*/
@Override
public Optional creationTime() {
return Optional.ofNullable(creationTime);
}
/**
* Sets the creation time of this key. This method can be useful when
* you have a raw key you are importing from somewhere else.
* @param creationTime creation time of this key
*/
public void setCreationTime(Instant creationTime) {
this.creationTime = Objects.requireNonNull(creationTime);
}
/**
* Clears the creation time of this key. This is mainly used deserialization and cloning. Normally you should not
* need to use this, as keys should have proper creation times whenever possible.
*/
public void clearCreationTime() {
this.creationTime = null;
}
/** @deprecated use {@link #setCreationTime(Instant)} */
@Deprecated
public void setCreationTimeSeconds(long creationTimeSecs) {
if (creationTimeSecs > 0)
setCreationTime(Instant.ofEpochSecond(creationTimeSecs));
else if (creationTimeSecs == 0)
clearCreationTime();
else
throw new IllegalArgumentException("Cannot set creation time to negative value: " + creationTimeSecs);
}
/**
* Create an encrypted private key with the keyCrypter and the AES key supplied.
* This method returns a new encrypted key and leaves the original unchanged.
*
* @param keyCrypter The keyCrypter that specifies exactly how the encrypted bytes are created.
* @param aesKey The KeyParameter with the AES encryption key (usually constructed with keyCrypter#deriveKey and cached as it is slow to create).
* @return encryptedKey
*/
public ECKey encrypt(KeyCrypter keyCrypter, AesKey aesKey) throws KeyCrypterException {
Objects.requireNonNull(keyCrypter);
final byte[] privKeyBytes = getPrivKeyBytes();
EncryptedData encryptedPrivateKey = keyCrypter.encrypt(privKeyBytes, aesKey);
ECKey result = ECKey.fromEncrypted(encryptedPrivateKey, keyCrypter, getPubKey());
if (creationTime != null)
result.setCreationTime(creationTime);
else
result.clearCreationTime();
return result;
}
/**
* Create a decrypted private key with the keyCrypter and AES key supplied. Note that if the aesKey is wrong, this
* has some chance of throwing KeyCrypterException due to the corrupted padding that will result, but it can also
* just yield a garbage key.
*
* @param keyCrypter The keyCrypter that specifies exactly how the decrypted bytes are created.
* @param aesKey The KeyParameter with the AES encryption key (usually constructed with keyCrypter#deriveKey and cached).
*/
public ECKey decrypt(KeyCrypter keyCrypter, AesKey aesKey) throws KeyCrypterException {
Objects.requireNonNull(keyCrypter);
// Check that the keyCrypter matches the one used to encrypt the keys, if set.
if (this.keyCrypter != null && !this.keyCrypter.equals(keyCrypter))
throw new KeyCrypterException("The keyCrypter being used to decrypt the key is different to the one that was used to encrypt it");
checkState(encryptedPrivateKey != null, () ->
"this key is not encrypted");
byte[] unencryptedPrivateKey = keyCrypter.decrypt(encryptedPrivateKey, aesKey);
if (unencryptedPrivateKey.length != 32)
throw new KeyCrypterException.InvalidCipherText(
"Decrypted key must be 32 bytes long, but is " + unencryptedPrivateKey.length);
ECKey key = ECKey.fromPrivate(unencryptedPrivateKey, isCompressed());
if (!Arrays.equals(key.getPubKey(), getPubKey()))
throw new KeyCrypterException("Provided AES key is wrong");
if (creationTime != null)
key.setCreationTime(creationTime);
else
key.clearCreationTime();
return key;
}
/**
* Create a decrypted private key with AES key. Note that if the AES key is wrong, this
* has some chance of throwing KeyCrypterException due to the corrupted padding that will result, but it can also
* just yield a garbage key.
*
* @param aesKey The KeyParameter with the AES encryption key (usually constructed with keyCrypter#deriveKey and cached).
*/
public ECKey decrypt(AesKey aesKey) throws KeyCrypterException {
final KeyCrypter crypter = getKeyCrypter();
if (crypter == null)
throw new KeyCrypterException("No key crypter available");
return decrypt(crypter, aesKey);
}
/**
* Creates decrypted private key if needed.
*/
public ECKey maybeDecrypt(@Nullable AesKey aesKey) throws KeyCrypterException {
return isEncrypted() && aesKey != null ? decrypt(aesKey) : this;
}
/**
* Check that it is possible to decrypt the key with the keyCrypter and that the original key is returned.
*
* Because it is a critical failure if the private keys cannot be decrypted successfully (resulting of loss of all
* bitcoins controlled by the private key) you can use this method to check when you *encrypt* a wallet that
* it can definitely be decrypted successfully.
*
* See {@link Wallet#encrypt(KeyCrypter keyCrypter, AesKey aesKey)} for example usage.
*
* @return true if the encrypted key can be decrypted back to the original key successfully.
*/
public static boolean encryptionIsReversible(ECKey originalKey, ECKey encryptedKey, KeyCrypter keyCrypter, AesKey aesKey) {
try {
ECKey rebornUnencryptedKey = encryptedKey.decrypt(keyCrypter, aesKey);
byte[] originalPrivateKeyBytes = originalKey.getPrivKeyBytes();
byte[] rebornKeyBytes = rebornUnencryptedKey.getPrivKeyBytes();
if (!Arrays.equals(originalPrivateKeyBytes, rebornKeyBytes)) {
log.error("The check that encryption could be reversed failed for {}", originalKey);
return false;
}
return true;
} catch (KeyCrypterException kce) {
log.error(kce.getMessage());
return false;
}
}
/**
* Indicates whether the private key is encrypted (true) or not (false).
* A private key is deemed to be encrypted when there is both a KeyCrypter and the encryptedPrivateKey is non-zero.
*/
@Override
public boolean isEncrypted() {
return keyCrypter != null && encryptedPrivateKey != null && encryptedPrivateKey.encryptedBytes.length > 0;
}
@Nullable
@Override
public Protos.Wallet.EncryptionType getEncryptionType() {
return keyCrypter != null ? keyCrypter.getUnderstoodEncryptionType() : Protos.Wallet.EncryptionType.UNENCRYPTED;
}
/**
* A wrapper for {@link #getPrivKeyBytes()} that returns null if the private key bytes are missing or would have
* to be derived (for the HD key case).
*/
@Override
@Nullable
public byte[] getSecretBytes() {
if (hasPrivKey())
return getPrivKeyBytes();
else
return null;
}
/** An alias for {@link #getEncryptedPrivateKey()} */
@Nullable
@Override
public EncryptedData getEncryptedData() {
return getEncryptedPrivateKey();
}
/**
* Returns the the encrypted private key bytes and initialisation vector for this ECKey, or null if the ECKey
* is not encrypted.
*/
@Nullable
public EncryptedData getEncryptedPrivateKey() {
return encryptedPrivateKey;
}
/**
* Returns the KeyCrypter that was used to encrypt to encrypt this ECKey. You need this to decrypt the ECKey.
*/
@Nullable
public KeyCrypter getKeyCrypter() {
return keyCrypter;
}
public static class MissingPrivateKeyException extends RuntimeException {
}
public static class KeyIsEncryptedException extends MissingPrivateKeyException {
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || !(o instanceof ECKey)) return false;
ECKey other = (ECKey) o;
return Objects.equals(this.priv, other.priv)
&& Objects.equals(this.pub, other.pub)
&& Objects.equals(this.creationTime, other.creationTime)
&& Objects.equals(this.keyCrypter, other.keyCrypter)
&& Objects.equals(this.encryptedPrivateKey, other.encryptedPrivateKey);
}
@Override
public int hashCode() {
return pub.hashCode();
}
@Override
public String toString() {
return toString(false, null, BitcoinNetwork.MAINNET);
}
/**
* Produce a string rendering of the ECKey INCLUDING the private key.
* Unless you absolutely need the private key it is better for security reasons to just use {@link #toString()}.
*/
public String toStringWithPrivate(@Nullable AesKey aesKey, Network network) {
return toString(true, aesKey, network);
}
/**
* Produce a string rendering of the ECKey INCLUDING the private key.
* Unless you absolutely need the private key it is better for security reasons to just use {@link #toString()}.
* @deprecated Use {@link #toStringWithPrivate(AesKey, Network)}
*/
@Deprecated
public String toStringWithPrivate(@Nullable AesKey aesKey, NetworkParameters params) {
return toStringWithPrivate(aesKey, params.network());
}
public String getPrivateKeyAsHex() {
return ByteUtils.formatHex(getPrivKeyBytes());
}
public String getPublicKeyAsHex() {
return ByteUtils.formatHex(pub.getEncoded());
}
public String getPrivateKeyAsWiF(Network network) {
return getPrivateKeyEncoded(network).toString();
}
/**
* @deprecated Use {@link #getPrivateKeyEncoded(Network)}
*/
@Deprecated
public String getPrivateKeyAsWiF(NetworkParameters params) {
return getPrivateKeyAsWiF(params.network());
}
private String toString(boolean includePrivate, @Nullable AesKey aesKey, Network network) {
final MoreObjects.ToStringHelper helper = MoreObjects.toStringHelper(this).omitNullValues();
helper.add("pub HEX", getPublicKeyAsHex());
if (includePrivate) {
ECKey decryptedKey = isEncrypted() ? decrypt(Objects.requireNonNull(aesKey)) : this;
try {
helper.add("priv HEX", decryptedKey.getPrivateKeyAsHex());
helper.add("priv WIF", decryptedKey.getPrivateKeyAsWiF(network));
} catch (IllegalStateException e) {
// TODO: Make hasPrivKey() work for deterministic keys and fix this.
} catch (Exception e) {
final String message = e.getMessage();
helper.add("priv EXCEPTION", e.getClass().getName() + (message != null ? ": " + message : ""));
}
}
if (creationTime != null)
helper.add("creationTime", creationTime);
helper.add("keyCrypter", keyCrypter);
if (includePrivate)
helper.add("encryptedPrivateKey", encryptedPrivateKey);
helper.add("isEncrypted", isEncrypted());
helper.add("isPubKeyOnly", isPubKeyOnly());
return helper.toString();
}
/**
* @deprecated Use {@link #toString(boolean, AesKey, Network)}
*/
@Deprecated
private String toString(boolean includePrivate, @Nullable AesKey aesKey, @Nullable NetworkParameters params) {
Network network = (params != null) ? params.network() : BitcoinNetwork.MAINNET;
return toString(includePrivate, aesKey, network);
}
public void formatKeyWithAddress(boolean includePrivateKeys, @Nullable AesKey aesKey, StringBuilder builder,
Network network, ScriptType outputScriptType, @Nullable String comment) {
builder.append(" addr:");
if (outputScriptType != null) {
builder.append(toAddress(outputScriptType, network));
} else {
builder.append(toAddress(ScriptType.P2PKH, network));
if (isCompressed())
builder.append(',').append(toAddress(ScriptType.P2WPKH, network));
}
if (!isCompressed())
builder.append(" UNCOMPRESSED");
builder.append(" hash160:");
builder.append(ByteUtils.formatHex(getPubKeyHash()));
if (creationTime != null)
builder.append(" creationTime:").append(creationTime).append(" [")
.append(TimeUtils.dateTimeFormat(creationTime)).append("]");
if (comment != null)
builder.append(" (").append(comment).append(")");
builder.append("\n");
if (includePrivateKeys) {
builder.append(" ");
builder.append(toStringWithPrivate(aesKey, network));
builder.append("\n");
}
}
/**
* @deprecated Use {@link #formatKeyWithAddress(boolean, AesKey, StringBuilder, Network, ScriptType, String)}
*/
@Deprecated
public void formatKeyWithAddress(boolean includePrivateKeys, @Nullable AesKey aesKey, StringBuilder builder,
NetworkParameters params, ScriptType outputScriptType, @Nullable String comment) {
formatKeyWithAddress(includePrivateKeys, aesKey, builder, params.network(), outputScriptType, comment);
}
/** The string that prefixes all text messages signed using Bitcoin keys. */
private static final String BITCOIN_SIGNED_MESSAGE_HEADER = "Bitcoin Signed Message:\n";
private static final byte[] BITCOIN_SIGNED_MESSAGE_HEADER_BYTES = BITCOIN_SIGNED_MESSAGE_HEADER.getBytes(StandardCharsets.UTF_8);
/**
* Given a textual message, returns a byte buffer formatted as follows:
* {@code [24] "Bitcoin Signed Message:\n" [message.length as a varint] message}
*/
private static byte[] formatMessageForSigning(String message) {
try {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bos.write(BITCOIN_SIGNED_MESSAGE_HEADER_BYTES.length);
bos.write(BITCOIN_SIGNED_MESSAGE_HEADER_BYTES);
byte[] messageBytes = message.getBytes(StandardCharsets.UTF_8);
VarInt size = VarInt.of(messageBytes.length);
bos.write(size.encode());
bos.write(messageBytes);
return bos.toByteArray();
} catch (IOException e) {
throw new RuntimeException(e); // Cannot happen.
}
}
}
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