Java相当于OpenSSL AES CBC加密

Posted 2021-03-28

我不是加密技术专家，特别是由于OpenSSL有很多缺少的文档，我不知道如何解决这个问题。

我有一个外部系统，希望接收加密的消息。提供的唯一示例以这种方式使用OpenSSL：

$ openssl enc -aes-256-cbc -a -in t.txt -k testpass
U2FsdGVkX1/RUdaSJKRXhHv3zUyTsQwu5/ar2ECKDlrNyH5GL4xRR4fgxkiWqkS1
cQstcoSIgWfRPSOFj/5OtdNLeNXiVR6MxSKJ+NvS9LyUD8+Rg6XIcYUvxR4gHi3w
DWT44LAMCpRAh1Q0t4Z2g7rwb0D05T6ygLaWvB5zD/xGZD3brTqSlWmiJb9Imgda
M6soZO7BhbYdqWqEUl5r6+EbkD21f6L3NX3hJFo+BJ+VFctiAlBO8NwT5l4ogo/s
GErm8gqRr57XoX/kvKAimg==

t.txt文件在一行中包含此字符串的位置：

AMOUNT=10&TID=#19:23&CURRENCY=EUR&LANGUAGE=DE&SUCCESS_URL=http://some.url/sucess&ERROR_URL=http://some.url/error&CONFIRMATION_URL=http://some.url/confirm&NAME=customer full name`

我找到了this的其他问题，我已经能够使用以下代码进行加密：

String password = "passPhrase";
String salt = "15charRandomSalt";
int iterations = 100;

/* Derive the key, given password and salt. */
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(password.toCharArray(), salt.getBytes(Charset.forName("UTF8")), iterations, 256);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");

/* Encrypt the message. */
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secret);
AlgorithmParameters params = cipher.getParameters();
byte[] iv = params.getParameterSpec(IvParameterSpec.class).getIV();
byte[] cipherText = cipher.doFinal(toBeEncrypted.getBytes("UTF-8"));
encryptedData = Base64.getEncoder().encodeToString(cipherText);
encryptedData += Base64.getEncoder().encodeToString(iv);

我无法理解的是我应该如何生成与OpenSSL相似的输出（encryptedData）。我有salt，iv和cipherText，是OpenSSL输出的Base64编码结果这些串联吗？或者只有一个？

我在加密之前与其他系统共享的唯一内容是密码短语。如果盐和迭代次数不为他们所知，他们怎么能解密结果呢？

有人可以给出那些未知参数的答案，并告诉我上面的代码是否等同于OpenSSL进程？

答案

以下是解密上述OPENSSL加密的Java程序（它需要Java 8）：

import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.MessageDigest;
import java.util.Arrays;
import java.util.Base64;
import java.util.Base64.Decoder;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class TestAesDecrypt {

    public static void main(final String[] args) throws Exception {
        final byte[] pass = "testpass".getBytes(StandardCharsets.US_ASCII);
        final byte[] magic = "Salted__".getBytes(StandardCharsets.US_ASCII);
        final String inFile = "e:/t/e.txt";

        String source = new String(Files.readAllBytes(Paths.get(inFile)),
                StandardCharsets.US_ASCII);
        source = source.replaceAll("\s", "");
        final Decoder decoder = Base64.getDecoder();
        final byte[] inBytes = decoder.decode(source);

        final byte[] shouldBeMagic = Arrays.copyOfRange(inBytes, 0,
                magic.length);
        if (!Arrays.equals(shouldBeMagic, magic)) {
            System.out.println("Bad magic number");
            return;
        }

        final byte[] salt = Arrays.copyOfRange(inBytes, magic.length,
                magic.length + 8);

        final byte[] passAndSalt = concat(pass, salt);

        byte[] hash = new byte[0];
        byte[] keyAndIv = new byte[0];
        for (int i = 0; i < 3; i++) {
            final byte[] data = concat(hash, passAndSalt);
            final MessageDigest md = MessageDigest.getInstance("MD5");
            hash = md.digest(data);
            keyAndIv = concat(keyAndIv, hash);
        }

        final byte[] keyValue = Arrays.copyOfRange(keyAndIv, 0, 32);
        final byte[] iv = Arrays.copyOfRange(keyAndIv, 32, 48);
        final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        final SecretKeySpec key = new SecretKeySpec(keyValue, "AES");
        cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
        final byte[] clear = cipher.doFinal(inBytes, 16, inBytes.length - 16);
        final String clearText = new String(clear, StandardCharsets.ISO_8859_1);
        System.out.println(clearText);
    }

    private static byte[] concat(final byte[] a, final byte[] b) {
        final byte[] c = new byte[a.length + b.length];
        System.arraycopy(a, 0, c, 0, a.length);
        System.arraycopy(b, 0, c, a.length, b.length);
        return c;
    }
}

另一答案

这个问题有一个已接受的答案，有点旧，但这似乎是一次又一次出现的事情。我有2个项目与第三方进行通信，密码是带有预共享密钥的OpenSSL AES。

我使用了not-yet-common-ssl库。然而它似乎停留在版本0.3.x并且在近两年内没有发布，没有任何邮件列表流量或可见的开发我必须得出结论，这基本上是死的。

基于一些额外的stackoverflow问题，我确实找到了Spring Security和Encryptor4j，它们似乎都提供了一些合理打包的文本编码。然而，试图让Spring Security的加密器解码已知的编码文本字符串失败对我来说，我猜测OpenSSL使用的IV和密钥生成在提供的实现中根本不受支持。

通过检查上面的代码，以及已知的工作C＃和php实现，我能够提出一个当前通过我的测试以实现互操作性的实用程序类。一般来说，我更喜欢使用一个已知的库，但如果有一个我无法找到它。班级（https://gist.github.com/rrsIPOV/4d0f6be7c58173c16e9edf9f97c7d7f2）如下：

import groovy.transform.CompileStatic;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.MessageDigest;
import java.security.SecureRandom;
import static java.nio.charset.StandardCharsets.*

/**
* Mimics the OpenSSL AES Cipher options for encrypting and decrypting messages using a shared key (aka password) with symetric ciphers.
*/
@CompileStatic
class OpenSslAes {

/** OpenSSL's magic initial bytes. */
private static final String SALTED_STR = "Salted__";
private static final byte[] SALTED_MAGIC = SALTED_STR.getBytes(US_ASCII);


static String encryptAndURLEncode(String password, String clearText) {
    String encrypted = encrypt(password, clearText);
    return URLEncoder.encode(encrypted, UTF_8.name() );
}

/**
 *
 * @param password  The password / key to encrypt with.
 * @param data      The data to encrypt
 * @return  A base64 encoded string containing the encrypted data.
 */
static String encrypt(String password, String clearText) {
    final byte[] pass = password.getBytes(US_ASCII);
    final byte[] salt = (new SecureRandom()).generateSeed(8);
    final byte[] inBytes = clearText.getBytes(UTF_8);

    final byte[] passAndSalt = array_concat(pass, salt);
    byte[] hash = new byte[0];
    byte[] keyAndIv = new byte[0];
    for (int i = 0; i < 3 && keyAndIv.length < 48; i++) {
        final byte[] hashData = array_concat(hash, passAndSalt);
        final MessageDigest md = MessageDigest.getInstance("MD5");
        hash = md.digest(hashData);
        keyAndIv = array_concat(keyAndIv, hash);
    }

    final byte[] keyValue = Arrays.copyOfRange(keyAndIv, 0, 32);
    final byte[] iv = Arrays.copyOfRange(keyAndIv, 32, 48);
    final SecretKeySpec key = new SecretKeySpec(keyValue, "AES");

    final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(iv));
    byte[] data = cipher.doFinal(inBytes);
    data =  array_concat(array_concat(SALTED_MAGIC, salt), data);
    return Base64.getEncoder().encodeToString( data );
}

/**
 * @see http://stackoverflow.com/questions/32508961/java-equivalent-of-an-openssl-aes-cbc-encryption  for what looks like a useful answer.  The not-yet-commons-ssl also has an implementation
 * @param password
 * @param source The encrypted data
 * @return
 */
static String decrypt(String password, String source) {
    final byte[] pass = password.getBytes(US_ASCII);

    final byte[] inBytes = Base64.getDecoder().decode(source);

    final byte[] shouldBeMagic = Arrays.copyOfRange(inBytes, 0, SALTED_MAGIC.length);
    if (!Arrays.equals(shouldBeMagic, SALTED_MAGIC)) {
        throw new IllegalArgumentException("Initial bytes from input do not match OpenSSL SALTED_MAGIC salt value.");
    }

    final byte[] salt = Arrays.copyOfRange(inBytes, SALTED_MAGIC.length, SALTED_MAGIC.length + 8);

    final byte[] passAndSalt = array_concat(pass, salt);

    byte[] hash = new byte[0];
    byte[] keyAndIv = new byte[0];
    for (int i = 0; i < 3 && keyAndIv.length < 48; i++) {
        final byte[] hashData = array_concat(hash, passAndSalt);
        final MessageDigest md = MessageDigest.getInstance("MD5");
        hash = md.digest(hashData);
        keyAndIv = array_concat(keyAndIv, hash);
    }

    final byte[] keyValue = Arrays.copyOfRange(keyAndIv, 0, 32);
    final SecretKeySpec key = new SecretKeySpec(keyValue, "AES");

    final byte[] iv = Arrays.copyOfRange(keyAndIv, 32, 48);

    final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
    final byte[] clear = cipher.doFinal(inBytes, 16, inBytes.length - 16);
    return new String(clear, UTF_8);
}


private static byte[] array_concat(final byte[] a, final byte[] b) {
    final byte[] c = new byte[a.length + b.length];
    System.arraycopy(a, 0, c, 0, a.length);
    System.arraycopy(b, 0, c, a.length, b.length);
    return c;
}
}

另一答案

您可以查看this discussion，将密钥生成算法指定为两个MD5哈希值的串联。

关于那里提到的盐，opensssl enc man page说：

当使用salt时，加密数据的前八个字节是为salt保留的：它在加密文件时随机生成，在解密时从加密文件中读取。

另一答案

此时openssl版本1.1.0f-3需要摘要功能SHA-256。没有它，它无法解码。