Java PKCS8EncodedKeySpec & X509EncodedKeySpec

String privateKey = "MIIBVAIBADANBgkqhkiG9w0BAQEFAASCAT4wggE6AgEAAkEApTHMs+zR16SE0v3npoVbMGo70xX5tJ7HF23SvM2rARkJNtRs4xZRQpWQ1JBZnGna9HcVQsrRAORqYhhTrZ9rMQIDAQABAkAFNrlYrasZErJGQEEiIWP9lwHCvZchLTB4j+TahIV+2iLTiLa21QOqQFmpBqw/uqmHsJGtqtHIXdtgCrGtoLVhAiEA4zpbZ52vkCskvZ2eJ34n6dTsiybZLIMYIdp21kd6mpECIQC6HJ2f0R6BwL/ORYhF6tA1YeXZEKyAuTgDkwgmGN/WoQIgPsXrZHeafbB9iOiXPX/LlPyekF6eFn7s1sVcmRvMEhECIBnJDS2vU4K2qdxyVccaGW7L+YRxgvTytIgKPv7IQ3sBAiEAh3XrxyuR3nJhFD5pPcRLmnst9Ag6WQuthc/SgkKJlXk=";
String publicKey = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAKUxzLPs0dekhNL956aFWzBqO9MV+bSexxdt0rzNqwEZCTbUbOMWUUKVkNSQWZxp2vR3FULK0QDkamIYU62fazECAwEAAQ==";

byte[] privateKeyEncoded = Base64.base64ToByteArray(privateKey);
byte[] publicKeyEncoded = Base64.base64ToByteArray(publicKey);

// 加密
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(privateKeyEncoded);
KeyFactory keyFactory = null;
try {
    keyFactory = KeyFactory.getInstance("RSA");
} catch (NoSuchAlgorithmException e) {
    Assert.fail("no such algorithm: " + e.getMessage());
}

PrivateKey privateKey = null;
try {
    privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
} catch (InvalidKeySpecException e) {
    Assert.fail("invalid key spec: " + e.getMessage());
}
System.out.println("private key: " + Base64.byteArrayToBase64(((Key) privateKey).getEncoded()));

// 解密
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(publicKeyEncoded);
try {
    keyFactory = KeyFactory.getInstance("RSA");
} catch (NoSuchAlgorithmException e) {
    Assert.fail("no such algorithm: " + e.getMessage());
}
PublicKey publicKey = null;
try {
    publicKey = keyFactory.generatePublic(x509KeySpec);
} catch (InvalidKeySpecException e) {
    Assert.fail("invalid key spec: " + e.getMessage());
}
System.out.println("public key: " + Base64.byteArrayToBase64(((Key) publicKey).getEncoded()));

完整代码

/**
 * private key: MIIBVAIBADANBgkqhkiG9w0BAQEFAASCAT4wggE6AgEAAkEApTHMs+zR16SE0v3npoVbMGo70xX5tJ7HF23SvM2rARkJNtRs4xZRQpWQ1JBZnGna9HcVQsrRAORqYhhTrZ9rMQIDAQABAkAFNrlYrasZErJGQEEiIWP9lwHCvZchLTB4j+TahIV+2iLTiLa21QOqQFmpBqw/uqmHsJGtqtHIXdtgCrGtoLVhAiEA4zpbZ52vkCskvZ2eJ34n6dTsiybZLIMYIdp21kd6mpECIQC6HJ2f0R6BwL/ORYhF6tA1YeXZEKyAuTgDkwgmGN/WoQIgPsXrZHeafbB9iOiXPX/LlPyekF6eFn7s1sVcmRvMEhECIBnJDS2vU4K2qdxyVccaGW7L+YRxgvTytIgKPv7IQ3sBAiEAh3XrxyuR3nJhFD5pPcRLmnst9Ag6WQuthc/SgkKJlXk=
 * public key: MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAKUxzLPs0dekhNL956aFWzBqO9MV+bSexxdt0rzNqwEZCTbUbOMWUUKVkNSQWZxp2vR3FULK0QDkamIYU62fazECAwEAAQ==
 */
@Test
public void test11() {
    String privateKey = "MIIBVAIBADANBgkqhkiG9w0BAQEFAASCAT4wggE6AgEAAkEApTHMs+zR16SE0v3npoVbMGo70xX5tJ7HF23SvM2rARkJNtRs4xZRQpWQ1JBZnGna9HcVQsrRAORqYhhTrZ9rMQIDAQABAkAFNrlYrasZErJGQEEiIWP9lwHCvZchLTB4j+TahIV+2iLTiLa21QOqQFmpBqw/uqmHsJGtqtHIXdtgCrGtoLVhAiEA4zpbZ52vkCskvZ2eJ34n6dTsiybZLIMYIdp21kd6mpECIQC6HJ2f0R6BwL/ORYhF6tA1YeXZEKyAuTgDkwgmGN/WoQIgPsXrZHeafbB9iOiXPX/LlPyekF6eFn7s1sVcmRvMEhECIBnJDS2vU4K2qdxyVccaGW7L+YRxgvTytIgKPv7IQ3sBAiEAh3XrxyuR3nJhFD5pPcRLmnst9Ag6WQuthc/SgkKJlXk=";
    String publicKey = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAKUxzLPs0dekhNL956aFWzBqO9MV+bSexxdt0rzNqwEZCTbUbOMWUUKVkNSQWZxp2vR3FULK0QDkamIYU62fazECAwEAAQ==";

    byte[] privateKeyEncoded = Base64.base64ToByteArray(privateKey);
    byte[] publicKeyEncoded = Base64.base64ToByteArray(publicKey);

    String message = "13120983870";
    System.out.println(message);

    encryptAndDecrypt(message, privateKeyEncoded, publicKeyEncoded);
}

private void encryptAndDecrypt(String message, byte[] privateKeyEncoded, byte[] publicKeyEncoded) {
    // 加密
    PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(privateKeyEncoded);
    KeyFactory keyFactory = null;
    try {
        keyFactory = KeyFactory.getInstance("RSA");
    } catch (NoSuchAlgorithmException e) {
        Assert.fail("no such algorithm: " + e.getMessage());
    }

    PrivateKey privateKey = null;
    try {
        privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
    } catch (InvalidKeySpecException e) {
        Assert.fail("invalid key spec: " + e.getMessage());
    }
    System.out.println("private key: " + Base64.byteArrayToBase64(((Key) privateKey).getEncoded()));

    Cipher cipher = null;
    try {
        cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    } catch (NoSuchAlgorithmException e) {
        Assert.fail("no such algorithm: " + e.getMessage());
    } catch (NoSuchPaddingException e) {
        Assert.fail("no such padding: " + e.getMessage());
    }
    try {
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
    } catch (InvalidKeyException e) {
        Assert.fail("invalid key: " + e.getMessage());
    }

    byte[] encryption = null;
    try {
        encryption = cipher.doFinal(message.getBytes());
    } catch (IllegalBlockSizeException e) {
        Assert.fail("illegal block size: " + e.getMessage());
    } catch (BadPaddingException e) {
        Assert.fail("bad padding: " + e.getMessage());
    }
    System.out.println("encryption: " + Base64.byteArrayToBase64(encryption));

    // 解密
    X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(publicKeyEncoded);
    try {
        keyFactory = KeyFactory.getInstance("RSA");
    } catch (NoSuchAlgorithmException e) {
        Assert.fail("no such algorithm: " + e.getMessage());
    }
    PublicKey publicKey = null;
    try {
        publicKey = keyFactory.generatePublic(x509KeySpec);
    } catch (InvalidKeySpecException e) {
        Assert.fail("invalid key spec: " + e.getMessage());
    }
    System.out.println("public key: " + Base64.byteArrayToBase64(((Key) publicKey).getEncoded()));
    try {
        cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    } catch (NoSuchAlgorithmException e) {
        Assert.fail("no such algorithm: " + e.getMessage());
    } catch (NoSuchPaddingException e) {
        Assert.fail("no such padding: " + e.getMessage());
    }
    try {
        cipher.init(Cipher.DECRYPT_MODE, publicKey);
    } catch (InvalidKeyException e) {
        Assert.fail("invalid key: " + e.getMessage());
    }

    byte[] decryption = null;
    try {
        decryption = cipher.doFinal(encryption);
    } catch (IllegalBlockSizeException e) {
        Assert.fail("illegal block size: " + e.getMessage());
    } catch (BadPaddingException e) {
        Assert.fail("bad padding: " + e.getMessage());
    }
    System.out.println("encryption: " + new String(decryption) + ", base64:" + Base64.byteArrayToBase64(decryption));
}