如何使用JJWT从用于PS256解析的base64嵌入式字符串创建Java Key对象

Question

我正在使用JJWT来尝试创建JWT密钥，并在稍后进行验证。当我尝试将键转换为字符串时，它不起作用，反之亦然——用于存储以备将来使用。

这个例子很好：

KeyPair keyPair = Keys.keyPairFor(SignatureAlgorithm.PS256);
Key publicKey = keyPair.getPublic();
Key privateKey = keyPair.getPrivate();
Claims claims = Jwts.claims();
claims.setIssuedAt(new Date());
String jws = Jwts.builder().setSubject("Joe").claim("Hello", "World").signWith(privateKey).compact();
boolean result = Jwts.parserBuilder().setSigningKey(publicKey).build().parseClaimsJws(jws).getBody().getSubject().equals("Joe");
System.out.println("Verified:" + result);
return "";

然而，当我将密钥转换为Base64Encoded字符串时：

String base64Public = Encoders.BASE64.encode(publicKey.getEncoded());
String base64Private = Encoders.BASE64.encode(privateKey.getEncoded());

如何将公钥(从字符串(加载回算法中，并使用公钥验证JWS？

String base64Public = Encoders.BASE64.encode(publicKey.getEncoded());
boolean result2 = Jwts.parserBuilder().setSigningKey(base64Public).build().parseClaimsJws(jws).getBody().getSubject().equals("Joe");

失败：

只能为HMAC签名指定密钥字节。请指定PublicKey或PrivateKey实例。

Answer 1

导出的公钥具有X.509/SPKI格式，必须相应导入：

import java.security.KeyFactory;
import java.security.spec.X509EncodedKeySpec;
import java.security.PublicKey;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.io.Encoders;
import io.jsonwebtoken.io.Decoders;
...
// Export
String base64Public = Encoders.BASE64.encode(publicKey.getEncoded());

// Import
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(Decoders.BASE64.decode(base64Public));
PublicKey publicKeyReloaded = (PublicKey)keyFactory.generatePublic(x509EncodedKeySpec);
// Verification 
boolean result = Jwts.parserBuilder().setSigningKey(publicKeyReloaded).build().parseClaimsJws(jws).getBody().getSubject().equals("Joe");
System.out.println("Verified:" + result); // Verified:true

编辑：

私钥具有PKCS#8格式，导入方式如下：

import java.security.KeyFactory;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.PrivateKey;
...
// Export
String base64Private = Encoders.BASE64.encode(privateKey.getEncoded());
// Import
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(base64Private));
PrivateKey privateKeyReloaded = (PrivateKey)keyFactory.generatePrivate(pkcs8EncodedKeySpec);
// Sign
String jws = Jwts.builder().setSubject("Joe").claim("Hello", "World").signWith(privateKeyReloaded).compact();
System.out.println("JWS:" + jws); // e.g. JWS:eyJhbGciOiJSUzI1NiJ9.eyJzdWIiOiJKb2UiLCJIZWxsbyI6IldvcmxkIn0.bk9EtxqRU3cfn7nMyn7MsDSKTlFUUwxjkWXVXqbpjVacEd6lEVG2jmkLSQ2oAoiA8fmKTlSXnULUKhv4XvDbvG2_BIx22JpceuYVdFhbvzkxv3EffPYrsYXftqws0vo-Wg05ubXk7qfeyIs9S-oq_Jf-5w_2oe6GLlcBqnNu-wLy8gAMiKNQPtuE7PmCT9ZEE7ALg_aGMBl2ttOEYN6bQcgxkbJLiS9pWm_RQbPsRCF34Q7alrETQPFltVJOPXd34aMPTaWSkYlyccj-0gVv8p5-BRpsGc3M9XaZWnwLm5CYzZ7tpfcd0BhKtkEO5mSFU7jo4P_T8BWCbEn2jYyzPA