读取DER格式的私钥

Question

我有以下代码来读取PKCS#8格式的私钥

public void encryptHash(String hashToEncrypt, String pathOfKey, String Algorithm) {
    FileInputStream fis = null;
    byte[] encodedKey = null;
    try {

        File f = new File(pathOfKey);
        encodedKey = new byte[(int)f.length()];

        fis = new FileInputStream(f);
        fis.read(encodedKey);
        fis.close();

        KeyFactory kf = KeyFactory.getInstance("RSA");
        PrivateKey privateKey = kf.generatePrivate(new PKCS8EncodedKeySpec(encodedKey));

        Signature rsaSigner = Signature.getInstance("SHA1withRSA");
        rsaSigner.initSign(privateKey);

        fis = new FileInputStream(hashToEncrypt);
        BufferedInputStream bis = new BufferedInputStream(fis);
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = bis.read(buffer)) >= 0) {
            try {
                rsaSigner.update(buffer, 0, len);
            } catch (SignatureException ex) {
                Logger.getLogger(DataEncryptor.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
        bis.close();

        byte[] signature = rsaSigner.sign();

        System.out.println(new String(signature));

    } catch (SignatureException ex) {
        Logger.getLogger(DataEncryptor.class.getName()).log(Level.SEVERE, null, ex);
    } catch (InvalidKeyException ex) {
        Logger.getLogger(DataEncryptor.class.getName()).log(Level.SEVERE, null, ex);
    } catch (InvalidKeySpecException ex) {
        Logger.getLogger(DataEncryptor.class.getName()).log(Level.SEVERE, null, ex);
    } catch (FileNotFoundException ex) {
        Logger.getLogger(DataEncryptor.class.getName()).log(Level.SEVERE, null, ex);
    } catch (IOException ex) {
        Logger.getLogger(DataEncryptor.class.getName()).log(Level.SEVERE, null, ex);
    } catch (NoSuchAlgorithmException ex) {
        Logger.getLogger(DataEncryptor.class.getName()).log(Level.SEVERE, null, ex);
    } finally {
        try {
            fis.close();
        } catch (IOException ex) {
            Logger.getLogger(DataEncryptor.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}

但是我得到了下面的异常。

dic 09, 2011 1:59:59 PM firmaelectronica.DataEncryptor encryptHash
Grave: null
java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: IOException : DER input, Integer tag error
    at sun.security.rsa.RSAKeyFactory.engineGeneratePrivate(RSAKeyFactory.java:217)
    at java.security.KeyFactory.generatePrivate(KeyFactory.java:372)
    at firmaelectronica.DataEncryptor.encryptHash(DataEncryptor.java:40)
    at firmaelectronica.FirmaElectronica.main(FirmaElectronica.java:39)
Caused by: java.security.InvalidKeyException: IOException : DER input, Integer tag error
    at sun.security.pkcs.PKCS8Key.decode(PKCS8Key.java:361)
    at sun.security.pkcs.PKCS8Key.decode(PKCS8Key.java:367)
    at sun.security.rsa.RSAPrivateCrtKeyImpl.<init>(RSAPrivateCrtKeyImpl.java:91)
    at sun.security.rsa.RSAPrivateCrtKeyImpl.newKey(RSAPrivateCrtKeyImpl.java:75)
    at sun.security.rsa.RSAKeyFactory.generatePrivate(RSAKeyFactory.java:316)
    at sun.security.rsa.RSAKeyFactory.engineGeneratePrivate(RSAKeyFactory.java:213)
    ... 3 more

你知道哪里出问题了吗？我在OpenSSL openssl pkcs8 -inform DER -in aaa010101aaa_FIEL.key -out aaa010101aaa_FIEL_key.pem上尝试过，它可以工作，但是当我想以DER格式读取密钥时，它会直接发送异常。

Answer 1

最后，看着这个帖子，Encrypting with RSA private key in Java找到了答案。

首先，我必须解开密钥，如下所示

openssl pkcs8 -inform DER -in myDERPassProtectedPrivate.key -outform PEM -out myPEMPrivate.key

它要求我输入密码，然后我让文件myPEMPrivate.key完成以下操作，删除保护密钥的密码，如下所示

openssl pkcs8 -topk8 -nocrypt -in myPEMPrivate.key -outform DER -out myNotAnyMoreProtectedPrivate.key

这样，我就可以用上面的代码加载密钥了。如果我们想在java中有一个受传递保护的密钥，强烈建议使用keystore。

附言:我试图避免2个步骤来摆脱用openssl pkcs8 -topk8 -nocrypt -inform der -in myDERPassProtectedPrivate.key -outform der -out myDERNoPassProtectedPrivate.key保护密钥的密码，但我不知道为什么我有错误错误解密密钥我使用WinOpenSSL，也许这就是我得到这个错误的原因。

Answer 2

使用以下命令：

-passin参数

输入文件密码源。有关arg格式的更多信息，请参阅openssl(1)中的密码短语参数部分。

命令应如下所示：

openssl pkcs8 -inform DER -in myDERPassProtectedPrivate.key -outform PEM -passin pass:12345678a -out myPEMPrivate.key

OpenSSL网站https://www.openssl.org/docs/apps/pkcs8.html