java - 生成并读取 Base64 私钥以从 java 签署 JWT token

Question

1-从命令行生成私钥:

openssl genrsa -aes256 -out private.key 2048

来自java，阅读它:

String privateKey = IOUtils.toString(TestJwtSecurityUtil.class.getResourceAsStream("/private.key"));
privateKey = privateKey.replace("-----BEGIN RSA PRIVATE KEY-----", "");
privateKey = privateKey.replace("-----END RSA PRIVATE KEY-----", "");
privateKey = privateKey.replaceAll("\\s+","");

byte[] encodedKey = DatatypeConverter.parseBase64Binary( privateKey );


PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(encodedKey);

KeyFactory kf = KeyFactory.getInstance("RSA");
PrivateKey pKey = kf.generatePrivate(keySpec); // fails

遇到异常:

Exception in thread "main" java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: IOException : DerInputStream.getLength(): lengthTag=58, too big.

我尝试转换为 base64:

byte[] encodedKey = DatatypeConverter.parseBase64Binary( encodedString );
 PrivateKey pKey = kf.generatePrivate(keySpec); // fails

得到:

Exception in thread "main" java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: invalid key format
    at java.base/sun.security.rsa.RSAKeyFactory.engineGeneratePrivate(RSAKeyFactory.java:251)

问:如何通过这个？为了让私钥被读取，最终我可以使用 JWT token :

final JwtBuilder builder = Jwts.builder().setId("id1")
                ....
                .signWith(signatureAlgorithm, pKey);

Answer 1

是的，它是重复的。但因为我花了 1 个多小时在 SO 网站上寻找它。基于此 reply 和 bouncycastle 的 PEMParser。谢谢，@dave_thompson_085

1. 创建私钥-公钥:

   • openssl genrsa -out private.key 4096
   • openssl rsa -pubout -in private.key -out public.key

2. 然后来自java

--

         final PrivateKey pKey = getPrivateKey();

         final SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.RS256; // private key to sign / public to confrim a sign
     final JwtBuilder builder = Jwts.builder().setId("id1")
                    .setIssuedAt(now)
                    .setSubject(subject)
                    .setIssuer(issuer)
                    .setAudience("api")
                    .addClaims(Map.of(
                            "user_name", "test user",
                            "authorities", List.of("ROLE_USER"),
                            "scope", List.of("read", "write"),
                            "client_id", "test-client"
                            )
                    )                     .signWith(signatureAlgorithm, pKey);

<小时/>

String jwt = builder.compact();

地点:

private static PrivateKey getPrivateKey() throws Exception {

        val path = TestUtils.class.getResource("/").getPath();

        final PEMParser pemParser = new PEMParser(new FileReader(path + "/private.key"));
        final JcaPEMKeyConverter converter = new JcaPEMKeyConverter().setProvider("BC");
        final PEMKeyPair object = (PEMKeyPair) pemParser.readObject();
        final KeyPair kp = converter.getKeyPair(object);
        final PrivateKey pKey = kp.getPrivate();

        return pKey;
    }

然后要检查，请将生成的 jwt 粘贴到 https://jwt.io/(或任何其他工具)以查看/检查内容。

将 public.key 内容放在那里以检查签名。看到一切都是绿色的。