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[英]Java/Kotlin AES-128-CBC encryption produces different result than OpenSSL
[英]Java equivalent of an OpenSSL AES CBC encryption
我不是密码学专家,特别是由于 OpenSSL 缺少很多文档,我不确定如何解决这个问题。
我有一个期望接收加密消息的外部系统。 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==
其中t.txt
文件在一行中包含此字符串:
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`
我发现了另一个问题,并且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 类似的输出(加密数据)。 我有 salt、iv 和 cipherText,OpenSSL 输出 Base64 编码结果是这些连接的结果吗? 还是只有其中一个?
在加密之前,我与其他系统共享的唯一内容是密码短语。 如果他们不知道盐和迭代次数,他们如何解密结果?
有人可以回答那些未知参数,并告诉我上面的代码是否相当于 OpenSSL 进程?
这个问题有一个公认的答案,有点旧,但这似乎是一次又一次出现的问题。 我有 2 个项目,我们与第 3 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 0.3.x 版本,并且在近 2 年内没有发布,没有任何邮件列表流量或可见的开发,我不得不得出结论,这基本上已经死了。
基于一些额外的 stackoverflow 问题,我确实发现Spring Security和Encryptor4j似乎都提供了一些合理打包的文本编码。 然而,试图让 Spring Security 的加密器解码已知编码的文本字符串对我来说失败了,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 C# 和 PHP 实现,我能够想出一个实用程序类,该类目前正在通过我的互操作性测试。 通常我更喜欢使用一个已知的库,但如果有一个我一直无法找到它。 类( 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;
}
}
以下是用于解密上述 OPENSSL 加密的 Java 程序(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;
}
}
您可以查看此讨论,将密钥生成算法指定为两个 MD5 哈希的串联。
关于那里提到的盐, opensssl enc 手册页说:
当使用 salt 时,加密数据的前 8 个字节是为 salt 保留的:它是在加密文件时随机生成的,并在解密时从加密文件中读取。
这时openssl 1.1.0f-3版需要一个摘要函数SHA-256。 没有这个,它就无法解码。
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