解密与Java的OpenSSL的PEM编码RSA私钥？解密与Java的OpenSSL的PEM编码RS

我有一个加密私钥和我知道密码。

我需要使用Java库对其进行解密。

我宁愿不使用，虽然BouncyCastle的，除非没有其他选择。 根据以往的经验，有太多的变化，并没有足够的文档。

私钥是这种形式：

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,56F3A98D9CFFA77A

X5h7SUDStF1tL16lRM+AfZb1UBDQ0D1YbQ6vmIlXiK....
.....
/KK5CZmIGw==
-----END RSA PRIVATE KEY-----

我认为关键数据是Base64编码的，因为我看到\r\n后64个字符。

我尝试了以下解密的关键：

import java.security.Key;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.spec.PKCS8EncodedKeySpec;
import javax.crypto.EncryptedPrivateKeyInfo;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;

public String decrypt(String keyDataStr, String passwordStr){
  // This key data start from "X5... to ==" 
  char [] password=passwordStr.toCharArray();
  byte [] keyDataBytes=com.sun.jersey.core.util.Base64.decode(keyDataStr);

  PBEKeySpec pbeSpec = new PBEKeySpec(password);
  EncryptedPrivateKeyInfo pkinfo = new EncryptedPrivateKeyInfo(keyDataBytes);
  SecretKeyFactory skf = SecretKeyFactory.getInstance(pkinfo.getAlgName());
  Key secret = skf.generateSecret(pbeSpec);
  PKCS8EncodedKeySpec keySpec = pkinfo.getKeySpec(secret);
  KeyFactory kf = KeyFactory.getInstance("RSA");
  PrivateKey pk=kf.generatePrivate(keySpec);
  return pk.toString();
}

我得到这个异常

java.io.IOException: DerInputStream.getLength(): lengthTag=50, too big.
    at sun.security.util.DerInputStream.getLength(DerInputStream.java:561)
    at sun.security.util.DerValue.init(DerValue.java:365)
    at sun.security.util.DerValue.<init>(DerValue.java:294)
    at javax.crypto.EncryptedPrivateKeyInfo.<init> (EncryptedPrivateKeyInfo.java:84)

我是不是传递给正确的参数EncryptedPrivateKeyInfo构造？

我怎样才能使这项工作？

我试了一下Ericsonn建议，用一个小的变化，因为我的工作Java 7的，我无法使用Base64.getMimeCoder（），而不是我用Base64.decode和我得到这个错误，我越来越喜欢这个输入长度的误差必须多在com.sun.crypto.provider.CipherCore.doFinal（CipherCore.java:750）与填充加密解密时的8

static RSAPrivateKey decrypt(String keyDataStr, String ivHex, String password)
            throws GeneralSecurityException, UnsupportedEncodingException
          {
            byte[] pw = password.getBytes(StandardCharsets.UTF_8);
            byte[] iv = h2b(ivHex);
            SecretKey secret = opensslKDF(pw, iv);
            Cipher cipher = Cipher.getInstance("DESede/CBC/NoPadding");
            cipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(iv));
            byte [] keyBytes=Base64.decode(keyDataStr.getBytes("UTF-8"));
            byte[] pkcs1 = cipher.doFinal(keyBytes);
            /* See note for definition of "decodeRSAPrivatePKCS1" */
            RSAPrivateCrtKeySpec spec = decodeRSAPrivatePKCS1(pkcs1);
            KeyFactory rsa = KeyFactory.getInstance("RSA");
            return (RSAPrivateKey) rsa.generatePrivate(spec);
          }

          private static SecretKey opensslKDF(byte[] pw, byte[] iv)
            throws NoSuchAlgorithmException
          {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            md5.update(pw);
            md5.update(iv);
            byte[] d0 = md5.digest();
            md5.update(d0);
            md5.update(pw);
            md5.update(iv);
            byte[] d1 = md5.digest();
            byte[] key = new byte[24];
            System.arraycopy(d0, 0, key, 0, 16);
            System.arraycopy(d1, 0, key, 16, 8);
            return new SecretKeySpec(key, "DESede");
          }

          private static byte[] h2b(CharSequence s)
          {
            int len = s.length();
            byte[] b = new byte[len / 2];
            for (int src = 0, dst = 0; src < len; ++dst) {
              int hi = Character.digit(s.charAt(src++), 16);
              int lo = Character.digit(s.charAt(src++), 16);
              b[dst] = (byte) (hi << 4 | lo);
            }
            return b;
          }
          static RSAPrivateCrtKeySpec decodeRSAPrivatePKCS1(byte[] encoded)
          {
            ByteBuffer input = ByteBuffer.wrap(encoded);
            if (der(input, 0x30) != input.remaining())
              throw new IllegalArgumentException("Excess data");
            if (!BigInteger.ZERO.equals(derint(input)))
              throw new IllegalArgumentException("Unsupported version");
            BigInteger n = derint(input);
            BigInteger e = derint(input);
            BigInteger d = derint(input);
            BigInteger p = derint(input);
            BigInteger q = derint(input);
            BigInteger ep = derint(input);
            BigInteger eq = derint(input);
            BigInteger c = derint(input);
            return new RSAPrivateCrtKeySpec(n, e, d, p, q, ep, eq, c);
          }

          private static BigInteger derint(ByteBuffer input)
          {
            byte[] value = new byte[der(input, 0x02)];
            input.get(value);
            return new BigInteger(+1, value);
          }


          private static int der(ByteBuffer input, int exp)
          {
            int tag = input.get() & 0xFF;
            if (tag != exp)
              throw new IllegalArgumentException("Unexpected tag");
            int n = input.get() & 0xFF;
            if (n < 128)
              return n;
            n &= 0x7F;
            if ((n < 1) || (n > 2))
              throw new IllegalArgumentException("Invalid length");
            int len = 0;
            while (n-- > 0) {
              len <<= 8;
              len |= input.get() & 0xFF;
            }
            return len;
          }

1640是keyDataStr.length（）和1228是keyBytes.length

Answer 1:

你需要使用一个非标准的，OpenSSL的方法推导出解密密钥。 然后用它来解密PKCS-＃1编码的关键是什么，你正在使用的不是 PKCS＃8信封。 您还需要从标题输入到这些过程IV。

它看起来是这样的：

  static RSAPrivateKey decrypt(String keyDataStr, String ivHex, String password)
    throws GeneralSecurityException
  {
    byte[] pw = password.getBytes(StandardCharsets.UTF_8);
    byte[] iv = h2b(ivHex);
    SecretKey secret = opensslKDF(pw, iv);
    Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
    cipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(iv));
    byte[] pkcs1 = cipher.doFinal(Base64.getMimeDecoder().decode(keyDataStr));
    /* See note for definition of "decodeRSAPrivatePKCS1" */
    RSAPrivateCrtKeySpec spec = decodeRSAPrivatePKCS1(pkcs1);
    KeyFactory rsa = KeyFactory.getInstance("RSA");
    return (RSAPrivateKey) rsa.generatePrivate(spec);
  }

  private static SecretKey opensslKDF(byte[] pw, byte[] iv)
    throws NoSuchAlgorithmException
  {
    MessageDigest md5 = MessageDigest.getInstance("MD5");
    md5.update(pw);
    md5.update(iv);
    byte[] d0 = md5.digest();
    md5.update(d0);
    md5.update(pw);
    md5.update(iv);
    byte[] d1 = md5.digest();
    byte[] key = new byte[24];
    System.arraycopy(d0, 0, key, 0, 16);
    System.arraycopy(d1, 0, key, 16, 8);
    return new SecretKeySpec(key, "DESede");
  }

  private static byte[] h2b(CharSequence s)
  {
    int len = s.length();
    byte[] b = new byte[len / 2];
    for (int src = 0, dst = 0; src < len; ++dst) {
      int hi = Character.digit(s.charAt(src++), 16);
      int lo = Character.digit(s.charAt(src++), 16);
      b[dst] = (byte) (hi << 4 | lo);
    }
    return b;
  }

这已经是一个很大的代码，所以我会链接到另一个答案的定义的decodeRSAPrivatePKCS1()方法。

Answer 2:

下面Java代码示例说明如何构建解密密钥，以获得从使用openssl 1.0.x的genrsa命令而建立的加密私钥底层RSA密钥; 特别是从可能已经利用了以下genrsa选项：

-des加密与DES CBC模式的生成的密钥

-des3埃德CBC模式用DES加密所生成的密钥（168位密钥）

与CBC AES -aes128，-aes192，-aes256加密PEM输出

上面的选项导致形式的加密的RSA私钥...

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AAA,BBB
...

这里AAA是之一：

DES-CBC，DES-EDE3-CBC，AES-128-CBC，AES-192-CBC，AES-256-CBC

AND BBB是十六进制编码的IV值

KeyFactory factory = KeyFactory.getInstance("RSA");
KeySpec keySpec = null;
RSAPrivateKey privateKey = null;

Matcher matcher = OPENSSL_ENCRYPTED_RSA_PRIVATEKEY_PATTERN.matcher(pemContents);
if (matcher.matches())
{
    String encryptionDetails = matcher.group(1).trim(); // e.g. AES-256-CBC,XXXXXXX
    String encryptedKey = matcher.group(2).replaceAll("\\s", ""); // remove tabs / spaces / newlines / carriage return etc

    System.out.println("PEM appears to be OpenSSL Encrypted RSA Private Key; Encryption details : "
        + encryptionDetails + "; Key : " + encryptedKey);

    byte[] encryptedBinaryKey = java.util.Base64.getDecoder().decode(encryptedKey);

    String[] encryptionDetailsParts = encryptionDetails.split(",");
    if (encryptionDetailsParts.length == 2)
    {
        String encryptionAlgorithm = encryptionDetailsParts[0];
        String encryptedAlgorithmParams = encryptionDetailsParts[1]; // i.e. the initialization vector in hex

        byte[] pw = new String(password).getBytes(StandardCharsets.UTF_8);
        byte[] iv = fromHex(encryptedAlgorithmParams);

        MessageDigest digest = MessageDigest.getInstance("MD5");

        // we need to come up with the encryption key

        // first round digest based on password and first 8-bytes of IV ..
        digest.update(pw);
        digest.update(iv, 0, 8);

        byte[] round1Digest = digest.digest(); // The digest is reset after this call is made.

        // second round digest based on first round digest, password, and first 8-bytes of IV ...
        digest.update(round1Digest);
        digest.update(pw);
        digest.update(iv, 0, 8);

        byte[] round2Digest = digest.digest();

        Cipher cipher = null;
        SecretKey secretKey = null;
        byte[] key = null;
        byte[] pkcs1 = null;

        if ("AES-256-CBC".equals(encryptionAlgorithm))
        {
            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");

            key = new byte[32]; // 256 bit key  (block size still 128-bit)
            System.arraycopy(round1Digest, 0, key, 0, 16);
            System.arraycopy(round2Digest, 0, key, 16, 16);

            secretKey = new SecretKeySpec(key, "AES");
        }
        else if ("AES-192-CBC".equals(encryptionAlgorithm))
        {
            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");

            key = new byte[24]; // key size of 24 bytes
            System.arraycopy(round1Digest, 0, key, 0, 16);
            System.arraycopy(round2Digest, 0, key, 16, 8);

            secretKey = new SecretKeySpec(key, "AES");
        }
        else if ("AES-128-CBC".equals(encryptionAlgorithm))
        {
            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");

            key = new byte[16]; // 128 bit key
            System.arraycopy(round1Digest, 0, key, 0, 16);

            secretKey = new SecretKeySpec(key, "AES");
        }
        else if ("DES-EDE3-CBC".equals(encryptionAlgorithm))
        {
            cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");

            key = new byte[24]; // key size of 24 bytes
            System.arraycopy(round1Digest, 0, key, 0, 16);
            System.arraycopy(round2Digest, 0, key, 16, 8);

            secretKey = new SecretKeySpec(key, "DESede");
        }
        else if ("DES-CBC".equals(encryptionAlgorithm))
        {
            cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

            key = new byte[8]; // key size of 8 bytes
            System.arraycopy(round1Digest, 0, key, 0, 8);

            secretKey = new SecretKeySpec(key, "DES");
        }

        cipher.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(iv));

        pkcs1 = cipher.doFinal(encryptedBinaryKey);

        keySpec = pkcs1ParsePrivateKey(pkcs1);

        privateKey = (RSAPrivateKey) factory.generatePrivate(keySpec);
    }
}

正则表达式...

static final String OPENSSL_ENCRYPTED_RSA_PRIVATEKEY_REGEX = "\\s*" 
+ "-----BEGIN RSA PUBLIC KEY-----" + "\\s*"
+ "Proc-Type: 4,ENCRYPTED" + "\\s*"
+ "DEK-Info:" + "\\s*([^\\s]+)" + "\\s+"
+ "([\\s\\S]*)"
+ "-----END RSA PUBLIC KEY-----" + "\\s*";

static final Pattern OPENSSL_ENCRYPTED_RSA_PRIVATEKEY_PATTERN = Pattern.compile(OPENSSL_ENCRYPTED_RSA_PRIVATEKEY_REGEX);

在fromHex（...）方法...

public static byte[] fromHex(String hexString)
{
    byte[] bytes = new byte[hexString.length() / 2];
    for (int i = 0; i < hexString.length(); i += 2)
    {
        bytes[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4)
            + Character.digit(hexString.charAt(i + 1), 16));
    }
    return bytes;
}

文章来源: Decrypting an OpenSSL PEM Encoded RSA private key with Java?