我正在使用 openssl 使用以下命令对字符串进行编码:
openssl enc -aes-128-cbc -a -salt -pass pass:mypassword <<< "stackoverflow"
结果给我一个编码字符串:U2FsdGVkX187CGv6DbEpqh/L6XRKON7uBGluIU0nT3w=
到现在为止,我只需要使用openssl解码它,所以以下命令返回先前编码的字符串:
openssl enc -aes-128-cbc -a -salt -pass pass:mypassword -d <<< "U2FsdGVkX187CGv6DbEpqh/L6XRKON7uBGluIU0nT3w="
结果:stackoverflow
现在,我需要解码 java应用程序中的编码字符串。
有人能为我提供一个简单的java类来解码用先前给定的openssl命令编码的字符串吗?
非常感谢。
答案 0 :(得分:4)
使用Bouncy Castle图书馆解决它。
以下是代码:
package example;
import java.util.Arrays;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.crypto.BufferedBlockCipher;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.InvalidCipherTextException;
import org.bouncycastle.crypto.engines.AESEngine;
import org.bouncycastle.crypto.generators.OpenSSLPBEParametersGenerator;
import org.bouncycastle.crypto.modes.CBCBlockCipher;
import org.bouncycastle.crypto.paddings.BlockCipherPadding;
import org.bouncycastle.crypto.paddings.PKCS7Padding;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
public class OpenSSLAesDecrypter
{
private static final int AES_NIVBITS = 128; // CBC Initialization Vector (same as cipher block size) [16 bytes]
private final int keyLenBits;
public OpenSSLAesDecrypter(int nKeyBits)
{
this.keyLenBits = nKeyBits;
}
public byte[] decipher(byte[] pwd, byte[] src)
{
// openssl non-standard extension: salt embedded at start of encrypted file
byte[] salt = Arrays.copyOfRange(src, 8, 16); // 0..7 is "SALTED__", 8..15 is the salt
try
{
// Encryption algorithm. Note that the "strength" (bitsize) is controlled by the key object that is used.
// Note that PKCS5 padding and PKCS7 padding are identical.
BlockCipherPadding padding = new PKCS7Padding();
BufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(new AESEngine()), padding);
CipherParameters params = getCipherParameters(pwd, salt);
cipher.reset();
cipher.init(false, params);
int buflen = cipher.getOutputSize(src.length - 16);
byte[] workingBuffer = new byte[buflen];
int len = cipher.processBytes(src, 16, src.length - 16, workingBuffer, 0);
len += cipher.doFinal(workingBuffer, len);
// Note that getOutputSize returns a number which includes space for "padding" bytes to be stored in.
// However we don't want these padding bytes; the "len" variable contains the length of the *real* data
// (which is always less than the return value of getOutputSize.
byte[] bytesDec = new byte[len];
System.arraycopy(workingBuffer, 0, bytesDec, 0, len);
return bytesDec;
}
catch (InvalidCipherTextException e)
{
System.err.println("Error: Decryption failed");
return null;
}
catch (RuntimeException e)
{
System.err.println("Error: Decryption failed");
return null;
}
}
private CipherParameters getCipherParameters(byte[] pwd, byte[] salt)
{
// Use bouncycastle implementation of openssl non-standard (pwd,salt)->(key,iv) algorithm.
// Note that if a "CBC" cipher is selected, then an IV is required as well as a key. When using a password,
// Openssl
// *derives* the IV from the (pwd,salt) pair at the same time as it derives the key.
//
// * PBE = Password Based Encryption
// * CBC = Cipher Block Chaining (ie IV is needed)
//
// Note also that when the IV is derived from (pwd, salt) the salt **must** be different for each message; this is
// the default for openssl - just make sure to NOT explicitly provide a salt, or encryption security is badly
// affected.
OpenSSLPBEParametersGenerator gen = new OpenSSLPBEParametersGenerator();
gen.init(pwd, salt);
CipherParameters cp = gen.generateDerivedParameters(keyLenBits, AES_NIVBITS);
return cp;
}
public static void main(String[] args)
{
OpenSSLAesDecrypter d = new OpenSSLAesDecrypter(128);
String r = new String(d.decipher("mypassword".getBytes(),
Base64.decodeBase64("U2FsdGVkX187CGv6DbEpqh/L6XRKON7uBGluIU0nT3w=")));
System.out.println(r);
}
}
使用以下依赖项来编译/运行它:
答案 1 :(得分:0)
openssl enc
使用(适度)非标准的基于密码的加密算法,以及自定义但简单的数据格式。
openssl enc
以十六进制表示-K
和-iv
,而Java加密表将它们作为字节;必要时转换。既然/如果您使用64-ed的密文,则首先取消de base64;这是在java8中提供的,并且有许多库可用于早期的Java版本。 否则您需要解压缩文件格式。在de-base64之后,丢弃前8个字节,将接下来的8个字节作为salt,将剩余的字节作为密文。
如果您需要特定算法AES128-CBC或192或256 和的PBE,您可以使用第三方加密库http://www.BouncyCastle.org,它为这三个实现openssl PBE算法。为SecretKeyFactory
实例化PBEWITHMD5AND128BITAES-CBC-OPENSSL
- 或192或256,但仅在安装了无限强度策略(更新:或Oracle版本&gt; = 8u161或OpenJDK)时 - 并为其指定PBEKeySpec
将键作为chars,salt和count为1,并将结果用于同一算法的Cipher
。
否则你必须自己做PBE。幸运的是(?)它非常简单。无论如何,请使用以下方法:
public static /*or as appropriate */ void opensslBytesToKey (
byte[] pass, byte[] salt /*or null*/, // inputs
int iter, String hashname, // PBKDF1-ish
byte[] key, byte[] iv /*or null*/ // outputs
) throws NoSuchAlgorithmException
{
MessageDigest md = MessageDigest.getInstance (hashname);
byte[] temp = null, out = new byte[key.length+(iv!=null?iv.length:0)];
int outidx = 0;
while(outidx < out.length){
if(temp!=null) md.update(temp);
md.update(pass);
if(salt!=null) md.update(salt);
temp = md.digest();
for(int i=1; i<iter; i++) temp = md.digest (temp);
int use = Math.min (out.length-outidx, temp.length);
System.arraycopy (temp,0, out,outidx, use);
outidx += use;
}
System.arraycopy (out,0, key,0, key.length);
if(iv!=null) System.arraycopy (out,key.length, iv,0, iv.length);
}
并使用密码作为字节,盐,迭代计数1,&#34; MD5&#34;以及输出数组(AES密钥的正确大小(16,24或32字节))和AES IV(总是16字节)。分别在SecretKeySpec
和IvParameterSpec
中使用Cipher
进行(更正)AES/CBC/PKCS5Padding
。
除此之外:您无法对字符串进行加密,只能字节(或更准确地说八位字节)。几乎所有系统上的C程序(包括openssl)都隐式地将字符串/字符以ASCII 方式转换为字节,但是使用ASCII集之外的任何字符可能会产生不一致和不可用的结果。 Java将字符串/字符视为 Unicode (或者更确切地说是UTF-16),将转换为字节,这些字节主要是显式的;对于ASCII,此转换是可靠的(并且与C一致),但对于非ASCII字符可能会有所不同。
更新:OpenSSL 1.1.0(2016-08)将enc
PBE的默认哈希值从MD5更改为SHA256。根据用于加密的OpenSSL版本,或者是否使用(以前未记录的)-md
选项,更改我的选项3中的调用。有关详细信息,请参阅(我的)https://crypto.stackexchange.com/questions/3298/is-there-a-standard-for-openssl-interoperable-aes-encryption/#35614