00 - Java常见的逆向代码以及python实现 | Java | Python | App逆向

3.逆向常见

3.1 接口中的方法

根据调用关系，最终找到接口中的方法了。

interface IRequest {
    public void send(String url);
}

class Context {

    public IRequest req;

    public Context(IRequest req) {
        this.req = req;
    }

    public void doRequest() {
        String url = "/click/android2/";
        this.req.send(url);
    }
}


public class Hello {

    public static void main(String[] args) {

    }
}

• 思路1：寻找实现了 IRequest 接口的类。
• 思路2：谁传入的req？找他的调用栈。

3.2 隐藏的字节

String v4 = new String(new byte[]{-26, -83, -90, -26, -78, -101, -23, -67, -112});

3.3 UUID

import java.util.UUID;

public class Hello {

    public static void main(String[] args){
        String uid = UUID.randomUUID().toString();
        System.out.println(uid);
    }
}

3.4 随机值

import java.math.BigInteger;
import java.security.SecureRandom;

public class Hello {

    public static void main(String[] args) {
        // 随机生成80位，10个字节
        BigInteger v4 = new BigInteger(80, new SecureRandom());
        // 让字节以16进制展示
        String res = v4.toString(16);
        System.out.println(res);

    }
}

import random

open_udid = "".join([hex(i)[2:] for i in random.randbytes(10)])
print(open_udid)

3.5 时间戳

public class Hello {

    public static void main(String[] args) {
        String t1 = String.valueOf(System.currentTimeMillis() / 1000);
        String t2 = String.valueOf(System.currentTimeMillis());

        System.out.println(t1);
        System.out.println(t2);
    }
}

3.6 十六进制字符串

import java.util.Arrays;

public class Hello {

    public static void main(String[] args) {

        String name = "\n武沛齐";
        byte[] nameBytes =name.getBytes();

        // [10, -26, -83, -90, -26, -78, -101, -23, -67, -112]
        //  0a   e6    ad   a6
        System.out.println(Arrays.toString(nameBytes));
        StringBuilder sb = new StringBuilder();
        for(int i=0;i<nameBytes.length;i++){
            int val = nameBytes[i] & 255;  // 负数转换为正数（byte，正数、负数）
            if (val<16){
                sb.append("0");
            }
            sb.append(Integer.toHexString(val));
        }
        String res = sb.toString();
        System.out.println(res); // e6ada6e6b29be9bd90

    }
}

name = "武沛齐"

data_list = []
for item in name.encode('utf-8'):
    val = hex(item)
    data = val[2:].zfill(2)
    data_list.append(data)

result = ''.join(data_list)
print(result) # e6ada6e6b29be9bd90

3.7 base64处理

import java.util.Base64;

public class Hello {

    public static void main(String[] args) {
        String name = "武沛齐";
        Base64.Encoder encoder  = Base64.getEncoder();
        String res = encoder.encodeToString(name.getBytes());
        System.out.println(res); // 5q2m5rKb6b2Q

        Base64.Decoder decoder  = Base64.getDecoder();
        byte[] origin = decoder.decode(res);
        String data = new String(origin);
        System.out.println(data); // 武沛齐

    }
}

import base64

name = "武沛齐"

res = base64.b64encode(name.encode('utf-8'))
print(res) # b'5q2m5rKb6b2Q'


data = base64.b64decode(res)
print(data.decode('utf-8'))

3.8 md5加密

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Base64;

public class Hello {

    public static void main(String[] args) throws NoSuchAlgorithmException {
        String name = "武沛齐";
        MessageDigest instance = MessageDigest.getInstance("MD5");
        byte[] nameBytes = instance.digest(name.getBytes());
        System.out.println(Arrays.toString(nameBytes));

        String res = new String(nameBytes);
        System.out.println(res);

        // 十六进制展示
        StringBuilder sb = new StringBuilder();
        for(int i=0;i<nameBytes.length;i++){
            int val = nameBytes[i] & 255;  // 负数转换为正数
            if (val<16){
                sb.append("0");
            }
            sb.append(Integer.toHexString(val));
        }
        String hexData = sb.toString();
        System.out.println(hexData); // e6ada6e6b29be9bd90
    }
}

import hashlib

m = hashlib.md5()
m.update("武沛齐".encode("utf-8"))
v1 = m.digest()
print(v1) # b'\x175\x10\x12G$)\xd5-\x0c\r#\xd4h\x17='
v2 = m.hexdigest()
print(v2) # 17351012472429d52d0c0d23d468173d

md5加盐

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Base64;

public class Hello {

    public static void main(String[] args) throws NoSuchAlgorithmException {
        String name = "武沛齐";
        MessageDigest instance = MessageDigest.getInstance("MD5");
        instance.update("xxxxxx".getBytes());
        byte[] nameBytes = instance.digest(name.getBytes());
        System.out.println(Arrays.toString(nameBytes));

        String res = new String(nameBytes);
        System.out.println(res);

        // 十六进制展示
        StringBuilder sb = new StringBuilder();
        for(int i=0;i<nameBytes.length;i++){
            int val = nameBytes[i] & 255;  // 负数转换为正数
            if (val<16){
                sb.append("0");
            }
            sb.append(Integer.toHexString(val));
        }
        String hexData = sb.toString();
        System.out.println(hexData); // e6ada6e6b29be9bd90
    }
}

import hashlib

m = hashlib.md5("xxxxxx".encode('utf-8'))
m.update("武沛齐".encode("utf-8"))
v1 = m.digest()
print(v1) # b'\x175\x10\x12G$)\xd5-\x0c\r#\xd4h\x17='
v2 = m.hexdigest()
print(v2) # 17351012472429d52d0c0d23d468173d

3.9 sha-256加密

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Base64;

public class Hello {

    public static void main(String[] args) throws NoSuchAlgorithmException {
        String name = "武沛齐";
        MessageDigest instance = MessageDigest.getInstance("SHA-256");
        byte[] nameBytes = instance.digest(name.getBytes());
        System.out.println(Arrays.toString(nameBytes));

        String res = new String(nameBytes);
        System.out.println(res);

        // 十六进制展示
        StringBuilder sb = new StringBuilder();
        for(int i=0;i<nameBytes.length;i++){
            int val = nameBytes[i] & 255;  // 负数转换为正数
            if (val<16){
                sb.append("0");
            }
            sb.append(Integer.toHexString(val));
        }
        String hexData = sb.toString();
        System.out.println(hexData); // e6ada6e6b29be9bd90
    }
}

import hashlib

m = hashlib.sha256()
m.update("武沛齐".encode("utf-8"))
v1 = m.digest()
print(v1)
v2 = m.hexdigest()
print(v2)

3.10 aes加密

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Base64;

public class Hello {

    public static void main(String[] args) throws Exception {
        String data = "武沛齐";
        String key = "fd6b639dbcff0c2a1b03b389ec763c4b";
        String iv = "77b07a672d57d64c";

        // 加密
        byte[] raw = key.getBytes();
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        IvParameterSpec ivSpec = new IvParameterSpec(iv.getBytes());
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, ivSpec);
        byte[] encrypted = cipher.doFinal(data.getBytes());
        System.out.println(Arrays.toString(encrypted));
        
    }
}

from Crypto.Cipher import AES
from Crypto.Util.Padding import pad

KEY = "fd6b639dbcff0c2a1b03b389ec763c4b"
IV = "77b07a672d57d64c"


def aes_encrypt(data_string):
    aes = AES.new(
        key=KEY.encode('utf-8'),
        mode=AES.MODE_CBC,
        iv=IV.encode('utf-8')
    )
    raw = pad(data_string.encode('utf-8'), 16)
    return aes.encrypt(raw)

data = aes_encrypt("武沛齐")
print(data)
print([ i for i in data])

3.11 gzip压缩

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.io.OutputStream;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class Hello {

    public static void main(String[] args) throws IOException {

        // 压缩
        String data = "武沛齐";
        // System.out.println(Arrays.toString(data.getBytes()));
        ByteArrayOutputStream v0_1 = new ByteArrayOutputStream();
        GZIPOutputStream v1 = new GZIPOutputStream((v0_1));
        v1.write(data.getBytes());
        v1.close();
        byte[] arg6 = v0_1.toByteArray();
        System.out.println(Arrays.toString(arg6));

        // 解压缩
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ByteArrayInputStream in = new ByteArrayInputStream(arg6);
        GZIPInputStream ungzip = new GZIPInputStream(in);
        byte[] buffer = new byte[256];
        int n;
        while ((n = ungzip.read(buffer)) >= 0) {
            out.write(buffer, 0, n);
        }
        byte[] res = out.toByteArray();
        // System.out.println(Arrays.toString(res));
        System.out.println(out.toString("UTF-8"));

    }
}

import gzip


# 压缩
"""
s_in = "我是武沛齐".encode('utf-8')
s_out = gzip.compress(s_in)
print([i for i in s_out])
"""

# 解压缩
"""
res = gzip.decompress(s_out)
print(res)
print(res.decode('utf-8'))
"""