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解密使用OpenSSL生成的“ der”文件时发生异常:使用填充密码解密时,输入长度必须是8的倍数

蒯硕
2023-03-14
问题内容

首先,我使用OpenSSL生成一个私有RSA密钥文件,然后将其转换为加密的“ der”文件:

$ openssl pkcs8 -topk8 -inform PEM -outform DER -in private_key.pem -out private_key.der

接下来,我尝试使用以下代码从Java解密此文件(在此阶段,我已经byte[] key使用本文底部的代码将文件读入数组):

public static byte[] decryptPrivateKey(byte[] key) throws IOException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
    PBEKeySpec passKeySpec = new PBEKeySpec("p".toCharArray()); //my password

    EncryptedPrivateKeyInfo encryptedKey = new EncryptedPrivateKeyInfo(key);
    System.out.println(encryptedKey.getAlgName());
    //PBEWithMD5AndDES
    System.out.println("key length: " + key.length);
    //key length: 677
    SecretKeyFactory keyFac = SecretKeyFactory.getInstance(encryptedKey.getAlgName());
    SecretKey passKey = keyFac.generateSecret(passKeySpec);

     // Create PBE Cipher
    Cipher pbeCipher = Cipher.getInstance(encryptedKey.getAlgName());
    // Initialize PBE Cipher with key and parameters
    pbeCipher.init(Cipher.DECRYPT_MODE, passKey, encryptedKey.getAlgParameters());

    // Decrypt the private key(throws the exception)
    return pbeCipher.doFinal(key);
}

我在上面的return语句上获得了以下堆栈跟踪:

Exception in thread "main" javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
    at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:750)
    at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:676)
    at com.sun.crypto.provider.PBECipherCore.doFinal(PBECipherCore.java:422)
    at com.sun.crypto.provider.PBEWithMD5AndDESCipher.engineDoFinal(PBEWithMD5AndDESCipher.java:316)
    at javax.crypto.Cipher.doFinal(Cipher.java:2087)
    at roland.test.crypto.Test.decryptPrivateKey(Test.java:96)
    at roland.test.crypto.Test.getPrivateKey(Test.java:74)
    at roland.test.crypto.Test.test(Test.java:58)
    at roland.test.crypto.Test.main(Test.java:30)

从“ der”文件中读取密钥作为字节数组:

public static PrivateKey getPrivateKey() throws Exception {
    byte[] key = null;
    try(final InputStream resourceStream = getMyClass().getResourceAsStream("private_key.der")) { //$NON-NLS-1$\r
        key = ByteStreams.toByteArray(resourceStream);
    } catch (IOException e) {
        e.printStackTrace();
    }

    key = decryptPrivateKey(key);
}

问题答案:

解决方案是:

return pbeCipher.doFinal(encryptedKey.getEncryptedData());


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