Java和Openssl为同一私钥生成不同长度的公钥

Question

我使用Java从私钥中生成公钥，如下所示，

    Security.addProvider(new BouncyCastleProvider());
    KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA", "BC");
    kpg.initialize(2048);
    KeyPair kp = kpg.generateKeyPair();
    PrivateKey priv = kp.getPrivate();
    RSAPrivateCrtKey rsaCrtKey = (RSAPrivateCrtKey) priv;
    RSAPublicKeySpec keyspecPublic =  new RSAPublicKeySpec(rsaCrtKey.getModulus(), rsaCrtKey.getPublicExponent());
    KeyFactory kf = KeyFactory.getInstance("RSA");
    PublicKey  publicKey2 = kf.generatePublic(keyspecPublic);
    String publicString = Base64.getMimeEncoder().encodeToString(publicKey2.getEncoded());
                StringBuilder sb = new StringBuilder("");
    sb.append("\"-----BEGIN PUBLIC KEY-----\\n")
       .append(publicString)
       .append("\\n-----END PUBLIC KEY-----");

然后我使用openssl为相同的私钥生成公钥，

openssl rsa -in private.key -pubout -out public.key

但是以上两种方法生成不同长度的字符串作为公共密钥。我在这里做错什么了吗？

java代码中的公钥：

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA6UkqbaGp7wOx2vrtqxmX/22ixKZcZPfZ
xXAawIst+AsWyNS+99MxnilstLIBKd6BCzJJsAa2I0ks43mnNZbkx1f1um+tQpXuTMbTh5MRprPn
jmX6aF+JXJbXATKhabTIQcCdpnrMi6scp9nWYkFdxVMfvo1gyThzfPwPgCO4eRFo1IkwZuergkl7
e0+U7WonqzFEb0joy5P78U+K8HebDW7nbS8zliq3DH2FI9yvEK3LeEN+Sa5icMWlERGv+7FCJVIH
CjBYfzaRZD9qqld/AnAEkCVt38SfSqWJECsnJYUW90WuFd8IxUVPS0TMfFMQhJFMT3eGweBOUb/b
pDm/hQIDAQAB
-----END PUBLIC KEY-----

来自openssl的公钥：

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA6UkqbaGp7wOx2vrtqxmX
/22ixKZcZPfZxXAawIst+AsWyNS+99MxnilstLIBKd6BCzJJsAa2I0ks43mnNZbk
x1f1um+tQpXuTMbTh5MRprPnjmX6aF+JXJbXATKhabTIQcCdpnrMi6scp9nWYkFd
xVMfvo1gyThzfPwPgCO4eRFo1IkwZuergkl7e0+U7WonqzFEb0joy5P78U+K8Heb
DW7nbS8zliq3DH2FI9yvEK3LeEN+Sa5icMWlERGv+7FCJVIHCjBYfzaRZD9qqld/
AnAEkCVt38SfSqWJECsnJYUW90WuFd8IxUVPS0TMfFMQhJFMT3eGweBOUb/bpDm/
hQIDAQAB
-----END PUBLIC KEY-----

Answer 1

密钥是相同的，并且将解码为相同的字节内容。

从格式上讲，Java封装在76列中，而OpenSSL封装在64列中。

如果要使换行一致，请使用Base64.getMimeEncoder(int lineLength, byte[] lineSeparator)重载方法，该方法可指定行长并将64作为lineLength参数传递。

Base64.getMimeEncoder(64, new byte[] {'\r', '\n'});