字符串转私钥 Ed25519

Question

我有一个字符串形式的私钥，我想将其转换为 PrivateKey

String privateKey = "Y2E3YjYwYzRjMDRjMjk1ZDQ5ZTQzM2RlMTdjZjVkNGE0NGFjYzJmM2IzOWExNWZhMjViNGE4ZWJiZDBiMDVkYTIwNGU4MWE3ZWZmMTQ0NGE2ZmM2NjExNzRmNTY4M2I0YmYyMTk5YTkyY2UzOWRkZjdmMzhkNTFjYTNmM2Q3ZDU";

byte[] pkcs8EncodedBytes = Base64.getDecoder().decode(privateKey);

PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(pkcs8EncodedBytes);

PrivateKey pkey = KeyFactory.getInstance("Ed25519") //NoSuchAlgorithmException
                            .generatePrivate(keySpec);

但是我得到这个错误：

java.security.NoSuchAlgorithmException: Ed25519 KeyFactory not available

在 KeyFactory.getInstance("Ed25519")

我正在使用 Java-10

Answer 1

发布的密钥经过双重编码，首先是十六进制，然后是 Base64。请注意，双重编码不是必需的。如果密钥是 Base64 和十六进制解码，结果是一个 64 字节的密钥。

从这个 64 字节的密钥开始，前 32 个字节是密钥，接下来的 32 个字节是 public 密钥。有关此格式的更多详细信息，请参见 here.

可以使用 Ed25519PrivateKeyParameters、Ed25519PublicKeyParameters 和 Ed25519Signer 使用 BouncyCastle 进行导入、签名和验证类:

import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import org.bouncycastle.crypto.Signer;
import org.bouncycastle.crypto.params.Ed25519PrivateKeyParameters;
import org.bouncycastle.crypto.params.Ed25519PublicKeyParameters;
import org.bouncycastle.crypto.signers.Ed25519Signer;
import org.bouncycastle.util.encoders.Hex;

// Base64, hex decode
String keyHexBase64 ="Y2E3YjYwYzRjMDRjMjk1ZDQ5ZTQzM2RlMTdjZjVkNGE0NGFjYzJmM2IzOWExNWZhMjViNGE4ZWJiZDBiMDVkYTIwNGU4MWE3ZWZmMTQ0NGE2ZmM2NjExNzRmNTY4M2I0YmYyMTk5YTkyY2UzOWRkZjdmMzhkNTFjYTNmM2Q3ZDU";
byte[] key = Hex.decode(new String(Base64.getDecoder().decode(keyHexBase64), StandardCharsets.UTF_8));

// Separate secret and public key
ByteBuffer keyBuffer = ByteBuffer.wrap(key);
byte[] secretKey = new byte[32];
keyBuffer.get(secretKey);
byte[] publicKey = new byte[keyBuffer.remaining()];
keyBuffer.get(publicKey);

// Signing
byte[] message = "The quick brown fox jumps over the lazy dog".getBytes(StandardCharsets.UTF_8);
Ed25519PrivateKeyParameters secretKeyParameters = new Ed25519PrivateKeyParameters(secretKey, 0);
Signer signer = new Ed25519Signer();
signer.init(true, secretKeyParameters);
signer.update(message, 0, message.length);
byte[] signature = signer.generateSignature();
System.out.println("Signature (hex): " + Hex.toHexString(signature));

// Verification
Ed25519PublicKeyParameters publicKeyParameters = new Ed25519PublicKeyParameters(publicKey, 0);
Signer verifier = new Ed25519Signer();
verifier.init(false, publicKeyParameters);
verifier.update(message, 0, message.length);
boolean verified = verifier.verifySignature(signature); // Signature (hex): 2aa31bb14799a00ac1129bdd6773a8481f0fd7e829d59f6fccc81021bf21e397dc5d17362d342615a5500598542586cad8891f984bdb90ec0c80b48eb638df07
System.out.println("Verification: " + verified); // Verification: true

关于BouncyCastle，需要bcprov-jdk15on，可以从Maven repository or from the BouncyCastle website.

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字符串转私钥 Ed25519

String to PrivateKey Ed25519

java

ed25519

private-key