从私钥派生 ECDSA Public 密钥
Deriving ECDSA Public Key from Private Key
我试图从私钥生成 public ECDSA 密钥，但我未能在 Internet 上找到太多关于如何执行此操作的帮助。几乎一切都是为了从 public 密钥规范生成 public 密钥，我不知道如何获得它。到目前为止，这是我放在一起的：
public void setPublic() throws GeneralSecurityException {
ECNamedCurveParameterSpec params = ECNamedCurveTable.getParameterSpec("secp256k1");
KeyFactory fact = KeyFactory.getInstance("ECDSA", "BC");
ECCurve curve = params.getCurve();
java.security.spec.EllipticCurve ellipticCurve = EC5Util.convertCurve(curve, params.getSeed());
java.security.spec.ECPoint point = ECPointUtil.decodePoint(ellipticCurve, this.privateKey.getEncoded());
java.security.spec.ECParameterSpec params2=EC5Util.convertSpec(ellipticCurve, params);
java.security.spec.ECPublicKeySpec keySpec = new java.security.spec.ECPublicKeySpec(point,params2);
this.publicKey = fact.generatePublic(keySpec);
}
但是，当 运行ning 时，出现以下错误：
Exception in thread "main" java.lang.IllegalArgumentException: Invalid point encoding 0x30
at org.bouncycastle.math.ec.ECCurve.decodePoint(Unknown Source)
at org.bouncycastle.jce.ECPointUtil.decodePoint(Unknown Source)
at Wallet.Wallet.setPublic(Wallet.java:125)
我做错了什么？有 better/easier 方法吗？
编辑：我设法编译了一些代码，但它无法正常工作：
public void setPublic() throws GeneralSecurityException {
BigInteger privKey = new BigInteger(getHex(privateKey.getEncoded()),16);
X9ECParameters ecp = SECNamedCurves.getByName("secp256k1");
ECPoint curvePt = ecp.getG().multiply(privKey);
BigInteger x = curvePt.getX().toBigInteger();
BigInteger y = curvePt.getY().toBigInteger();
byte[] xBytes = removeSignByte(x.toByteArray());
byte[] yBytes = removeSignByte(y.toByteArray());
byte[] pubKeyBytes = new byte[65];
pubKeyBytes[0] = new Byte("04");
System.arraycopy(xBytes, 0, pubKeyBytes, 1, xBytes.length);
System.arraycopy(yBytes, 0, pubKeyBytes, 33, xBytes.length);
ECNamedCurveParameterSpec params = ECNamedCurveTable.getParameterSpec("secp256k1");
KeyFactory fact = KeyFactory.getInstance("ECDSA", "BC");
ECCurve curve = params.getCurve();
java.security.spec.EllipticCurve ellipticCurve = EC5Util.convertCurve(curve, params.getSeed());
java.security.spec.ECPoint point = ECPointUtil.decodePoint(ellipticCurve, pubKeyBytes);
java.security.spec.ECParameterSpec params2 = EC5Util.convertSpec(ellipticCurve, params);
java.security.spec.ECPublicKeySpec keySpec = new java.security.spec.ECPublicKeySpec(point,params2);
this.publicKey = fact.generatePublic(keySpec);
}
private byte[] removeSignByte(byte[] arr)
{
if(arr.length==33)
{
byte[] newArr = new byte[32];
System.arraycopy(arr, 1, newArr, 0, newArr.length);
return newArr;
}
return arr;
}
当我运行它时，它会生成一个public密钥，但它与私钥对应的不是同一个。
所以过了一会儿，我想出了一个解决方案并决定 post 它以防其他人遇到与我相同的问题：
KeyFactory keyFactory = KeyFactory.getInstance("ECDSA", "BC");
ECParameterSpec ecSpec = ECNamedCurveTable.getParameterSpec("secp256k1");
ECPoint Q = ecSpec.getG().multiply(((org.bouncycastle.jce.interfaces.ECPrivateKey) this.privateKey).getD());
ECPublicKeySpec pubSpec = new ECPublicKeySpec(Q, ecSpec);
PublicKey publicKeyGenerated = keyFactory.generatePublic(pubSpec);
this.publicKey = publicKeyGenerated;
编辑：根据@MaartenBodewes 评论删除了解码 ECPoint 的代码。
在前面的答案的基础上，可以将其扩展到所有给出的是满足 BCECPrivateKey 接口的私钥的情况：
DerivePubKeyFromPrivKey(BCECPrivateKey definingKey, Provider provider) {
KeyFactory keyFactory = KeyFactory.getInstance("EC", provider);
BigInteger d = definingKey.getD();
org.bouncycastle.jce.spec.ECParameterSpec ecSpec =
definingKey.getParameters();
ECPoint Q = definingKey.getParameters().getG().multiply(d);
org.bouncycastle.jce.spec.ECPublicKeySpec pubSpec = new
org.bouncycastle.jce.spec.ECPublicKeySpec(Q, ecSpec);
PublicKey publicKeyGenerated = keyFactory.generatePublic(pubSpec);
return publicKeyGenerated;
}
我来到这里时遇到了 Kotlin 中的同样问题，因此，如果它对任何人有帮助，下面是我如何从 Kotlin 中的 ECDSA PrivateKey 中导出 PublicKey。此代码基于，然后反复试验直到成功。
在我的例子中，我知道我的密钥使用了 secp256k1 曲线，所以我可以对该部分进行硬编码。我没有费心去学习如何将它推广到其他曲线。
import java.security.KeyFactory
import java.security.KeyPair
import java.security.PrivateKey
import java.security.PublicKey
import org.bouncycastle.asn1.pkcs.PrivateKeyInfo
import org.bouncycastle.jce.ECNamedCurveTable
import org.bouncycastle.jce.interfaces.ECPrivateKey
import org.bouncycastle.jce.spec.ECNamedCurveParameterSpec
import org.bouncycastle.jce.spec.ECPublicKeySpec
import org.bouncycastle.math.ec.ECPoint
import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter
import org.bouncycastle.openssl.PEMParser
fun getECPrivateKeyFromPEM(privatePem: String): ECPrivateKey {
val pemParser = PEMParser(privatePem.reader())
val privateKeyInfo = pemParser.readObject() as PrivateKeyInfo
return JcaPEMKeyConverter().getPrivateKey(privateKeyInfo) as ECPrivateKey
}
fun getKeyPairFromECPrivateKey(privateKey: ECPrivateKey): KeyPair {
val keyFactory: KeyFactory = KeyFactory.getInstance("ECDSA", "BC")
val spec: ECNamedCurveParameterSpec = ECNamedCurveTable.getParameterSpec("secp256k1")
val Q: ECPoint = spec.getG().multiply(privateKey.getD())
val publicKey: PublicKey = keyFactory.generatePublic(ECPublicKeySpec(Q, spec))
return KeyPair(publicKey, privateKey)
}
这是我的测试工具：
import java.io.StringWriter
import org.bouncycastle.openssl.jcajce.JcaPEMWriter
fun main() {
val privatePem = """
|-----BEGIN PRIVATE KEY-----
|MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQg55EMdhNJX+YN/bjN
|Eof91oKqEqD0QidEsRMhHBwSRjShRANCAARnSFpE0LDugORBWlSJz0Zf9e0mR9s6
|tlxSeo1Nbd2vv9LDedm+l/CfZpbyYvPm49DAKDhkUHFIVDd2SsiPrRa7
|-----END PRIVATE KEY-----
""".trimMargin()
val privateKey: ECPrivateKey = getECPrivateKeyFromPEM(privatePem)
val pair: KeyPair = getKeyPairFromECPrivateKey(privateKey)
val pems: String = StringWriter().use {
val pemWriter = JcaPEMWriter(it)
pemWriter.writeObject(pair.getPublic())
pemWriter.writeObject(pair.getPrivate())
pemWriter.flush()
it.toString()
}
println(pems)
}
打印出来：
-----BEGIN PUBLIC KEY-----
MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAEcE4HMAHLDvPr6xHKsjhPXJzTdxLlRRR8
BfYnI2TGb0QLTFyyXm13CeYiLnxbkGhSvz9ZRo0zGQygKPVpgiThSw==
-----END PUBLIC KEY-----
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIOeRDHYTSV/mDf24zRKH/daCqhKg9EInRLETIRwcEkY0oAoGCCqGSM49
AwEHoUQDQgAEZ0haRNCw7oDkQVpUic9GX/XtJkfbOrZcUnqNTW3dr7/Sw3nZvpfw
n2aW8mLz5uPQwCg4ZFBxSFQ3dkrIj60Wuw==
-----END EC PRIVATE KEY-----
我试图从私钥生成 public ECDSA 密钥，但我未能在 Internet 上找到太多关于如何执行此操作的帮助。几乎一切都是为了从 public 密钥规范生成 public 密钥，我不知道如何获得它。到目前为止，这是我放在一起的：
public void setPublic() throws GeneralSecurityException {
ECNamedCurveParameterSpec params = ECNamedCurveTable.getParameterSpec("secp256k1");
KeyFactory fact = KeyFactory.getInstance("ECDSA", "BC");
ECCurve curve = params.getCurve();
java.security.spec.EllipticCurve ellipticCurve = EC5Util.convertCurve(curve, params.getSeed());
java.security.spec.ECPoint point = ECPointUtil.decodePoint(ellipticCurve, this.privateKey.getEncoded());
java.security.spec.ECParameterSpec params2=EC5Util.convertSpec(ellipticCurve, params);
java.security.spec.ECPublicKeySpec keySpec = new java.security.spec.ECPublicKeySpec(point,params2);
this.publicKey = fact.generatePublic(keySpec);
}
但是，当 运行ning 时，出现以下错误：
Exception in thread "main" java.lang.IllegalArgumentException: Invalid point encoding 0x30
at org.bouncycastle.math.ec.ECCurve.decodePoint(Unknown Source)
at org.bouncycastle.jce.ECPointUtil.decodePoint(Unknown Source)
at Wallet.Wallet.setPublic(Wallet.java:125)
我做错了什么？有 better/easier 方法吗？
编辑：我设法编译了一些代码，但它无法正常工作：
public void setPublic() throws GeneralSecurityException {
BigInteger privKey = new BigInteger(getHex(privateKey.getEncoded()),16);
X9ECParameters ecp = SECNamedCurves.getByName("secp256k1");
ECPoint curvePt = ecp.getG().multiply(privKey);
BigInteger x = curvePt.getX().toBigInteger();
BigInteger y = curvePt.getY().toBigInteger();
byte[] xBytes = removeSignByte(x.toByteArray());
byte[] yBytes = removeSignByte(y.toByteArray());
byte[] pubKeyBytes = new byte[65];
pubKeyBytes[0] = new Byte("04");
System.arraycopy(xBytes, 0, pubKeyBytes, 1, xBytes.length);
System.arraycopy(yBytes, 0, pubKeyBytes, 33, xBytes.length);
ECNamedCurveParameterSpec params = ECNamedCurveTable.getParameterSpec("secp256k1");
KeyFactory fact = KeyFactory.getInstance("ECDSA", "BC");
ECCurve curve = params.getCurve();
java.security.spec.EllipticCurve ellipticCurve = EC5Util.convertCurve(curve, params.getSeed());
java.security.spec.ECPoint point = ECPointUtil.decodePoint(ellipticCurve, pubKeyBytes);
java.security.spec.ECParameterSpec params2 = EC5Util.convertSpec(ellipticCurve, params);
java.security.spec.ECPublicKeySpec keySpec = new java.security.spec.ECPublicKeySpec(point,params2);
this.publicKey = fact.generatePublic(keySpec);
}
private byte[] removeSignByte(byte[] arr)
{
if(arr.length==33)
{
byte[] newArr = new byte[32];
System.arraycopy(arr, 1, newArr, 0, newArr.length);
return newArr;
}
return arr;
}
当我运行它时，它会生成一个public密钥，但它与私钥对应的不是同一个。
所以过了一会儿，我想出了一个解决方案并决定 post 它以防其他人遇到与我相同的问题：
KeyFactory keyFactory = KeyFactory.getInstance("ECDSA", "BC");
ECParameterSpec ecSpec = ECNamedCurveTable.getParameterSpec("secp256k1");
ECPoint Q = ecSpec.getG().multiply(((org.bouncycastle.jce.interfaces.ECPrivateKey) this.privateKey).getD());
ECPublicKeySpec pubSpec = new ECPublicKeySpec(Q, ecSpec);
PublicKey publicKeyGenerated = keyFactory.generatePublic(pubSpec);
this.publicKey = publicKeyGenerated;
编辑：根据@MaartenBodewes 评论删除了解码 ECPoint 的代码。
在前面的答案的基础上，可以将其扩展到所有给出的是满足 BCECPrivateKey 接口的私钥的情况：
DerivePubKeyFromPrivKey(BCECPrivateKey definingKey, Provider provider) {
KeyFactory keyFactory = KeyFactory.getInstance("EC", provider);
BigInteger d = definingKey.getD();
org.bouncycastle.jce.spec.ECParameterSpec ecSpec =
definingKey.getParameters();
ECPoint Q = definingKey.getParameters().getG().multiply(d);
org.bouncycastle.jce.spec.ECPublicKeySpec pubSpec = new
org.bouncycastle.jce.spec.ECPublicKeySpec(Q, ecSpec);
PublicKey publicKeyGenerated = keyFactory.generatePublic(pubSpec);
return publicKeyGenerated;
}
我来到这里时遇到了 Kotlin 中的同样问题，因此，如果它对任何人有帮助，下面是我如何从 Kotlin 中的 ECDSA PrivateKey 中导出 PublicKey。此代码基于
在我的例子中，我知道我的密钥使用了 secp256k1 曲线，所以我可以对该部分进行硬编码。我没有费心去学习如何将它推广到其他曲线。
import java.security.KeyFactory
import java.security.KeyPair
import java.security.PrivateKey
import java.security.PublicKey
import org.bouncycastle.asn1.pkcs.PrivateKeyInfo
import org.bouncycastle.jce.ECNamedCurveTable
import org.bouncycastle.jce.interfaces.ECPrivateKey
import org.bouncycastle.jce.spec.ECNamedCurveParameterSpec
import org.bouncycastle.jce.spec.ECPublicKeySpec
import org.bouncycastle.math.ec.ECPoint
import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter
import org.bouncycastle.openssl.PEMParser
fun getECPrivateKeyFromPEM(privatePem: String): ECPrivateKey {
val pemParser = PEMParser(privatePem.reader())
val privateKeyInfo = pemParser.readObject() as PrivateKeyInfo
return JcaPEMKeyConverter().getPrivateKey(privateKeyInfo) as ECPrivateKey
}
fun getKeyPairFromECPrivateKey(privateKey: ECPrivateKey): KeyPair {
val keyFactory: KeyFactory = KeyFactory.getInstance("ECDSA", "BC")
val spec: ECNamedCurveParameterSpec = ECNamedCurveTable.getParameterSpec("secp256k1")
val Q: ECPoint = spec.getG().multiply(privateKey.getD())
val publicKey: PublicKey = keyFactory.generatePublic(ECPublicKeySpec(Q, spec))
return KeyPair(publicKey, privateKey)
}
这是我的测试工具：
import java.io.StringWriter
import org.bouncycastle.openssl.jcajce.JcaPEMWriter
fun main() {
val privatePem = """
|-----BEGIN PRIVATE KEY-----
|MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQg55EMdhNJX+YN/bjN
|Eof91oKqEqD0QidEsRMhHBwSRjShRANCAARnSFpE0LDugORBWlSJz0Zf9e0mR9s6
|tlxSeo1Nbd2vv9LDedm+l/CfZpbyYvPm49DAKDhkUHFIVDd2SsiPrRa7
|-----END PRIVATE KEY-----
""".trimMargin()
val privateKey: ECPrivateKey = getECPrivateKeyFromPEM(privatePem)
val pair: KeyPair = getKeyPairFromECPrivateKey(privateKey)
val pems: String = StringWriter().use {
val pemWriter = JcaPEMWriter(it)
pemWriter.writeObject(pair.getPublic())
pemWriter.writeObject(pair.getPrivate())
pemWriter.flush()
it.toString()
}
println(pems)
}
打印出来：
-----BEGIN PUBLIC KEY-----
MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAEcE4HMAHLDvPr6xHKsjhPXJzTdxLlRRR8
BfYnI2TGb0QLTFyyXm13CeYiLnxbkGhSvz9ZRo0zGQygKPVpgiThSw==
-----END PUBLIC KEY-----
-----BEGIN EC PRIVATE KEY-----
MHcCAQEEIOeRDHYTSV/mDf24zRKH/daCqhKg9EInRLETIRwcEkY0oAoGCCqGSM49
AwEHoUQDQgAEZ0haRNCw7oDkQVpUic9GX/XtJkfbOrZcUnqNTW3dr7/Sw3nZvpfw
n2aW8mLz5uPQwCg4ZFBxSFQ3dkrIj60Wuw==
-----END EC PRIVATE KEY-----