C# 三元组：指定的密钥是'；三倍体'；不能使用
我正在使用.NET3.0类C# 三元组：指定的密钥是'；三倍体'；不能使用,c#,.net,cryptography,cryptographicexception,C#,.net,Cryptography,Cryptographicexception,我正在使用.NET3.0类System.Security.Cryptography.MACTripleDES类生成MAC值。不幸的是，我使用的硬件设备使用“1111111111”（十六进制）作为单个长度的DES键。System.Security.Cryptography库对密钥执行一些健全性检查，如果尝试使用加密弱密钥，则返回异常 例如： byte[] key = new byte[24]; for (int i = 0; i < key.Length; i++) key[i] = 0
System.Security.Cryptography.MACTripleDES1111111111System.Security.Cryptographybyte[] key = new byte[24];
for (int i = 0; i < key.Length; i++)
key[i] = 0x11;
byte[] data = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
byte[] computedMac = null;
using (MACTripleDES mac = new MACTripleDES(key))
{
computedMac = mac.ComputeHash(data);
}
app.config编辑2：丹尼尔在下面的回答中提供了一些关于黑客攻击.NET的非常好的信息。不幸的是，我无法使用此技术解决我的问题，但仍然有一些有趣的阅读。不幸的是，该行为无法被覆盖。我不推荐使用此技术，但您应该能够使用和外接程序修改检查弱密钥的IL代码 编辑： 对不起，我花了一段时间才把它全部加载到我的虚拟机（运行Ubuntu）中，我不想弄乱Mono
- 安装Reflecil加载项：查看->加载项->添加
- 打开ReflexIL:Tools->ReflexIL v0.9
- 查找IsWeakKey（）函数。（您可以使用搜索：F3）
- 将出现两个函数，双击System.Security.Cryptography.TripleDES中的函数
- 雷科菲尔也应该来。在“说明”选项卡中，向下滚动至第29行（偏移量63）
- 将ldc.i4.1更改为ldc.i4.0，这意味着函数将始终返回false
- 首先备份您的原始程序集！（mscorlib.dll）
- mscorlib.dll是一个已签名的程序集，您需要reflecil的.NET SDK（sn.exe工具）使其跳过验证。我刚刚亲自检查过，您应该已经安装了Visual C。当要求注册时，只需单击“注册以跳过验证（在此计算机上）”
- 我不认为我必须告诉您只在您的开发机器上使用这个：）
我放弃了。我希望有人能回答到底发生了什么事，因为我确实不知道。：） 我不是安全专家，但是用另一个值对您的密钥进行异或不足以满足安全检查吗？您可以对调试版本（使用适当的IFDEF）执行此操作，以便在密钥足够强大的版本或生产版本中执行适当的检查并删除它。不必使用重复DES密钥的MACTripleDES来伪造单个DES CBC-MAC，您可以自己在其上实现CBC-MAC 不是一个弱DES键 这将计算DES CBC-MAC：
public static byte[] CalcDesMac(byte[] key, byte[] data){
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
des.Key = key;
des.IV = new byte[8];
des.Padding = PaddingMode.Zeros;
MemoryStream ms = new MemoryStream();
using(CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write)){
cs.Write(data, 0, data.Length);
}
byte[] encryption = ms.ToArray();
byte[] mac = new byte[8];
Array.Copy(encryption, encryption.Length-8, mac, 0, 8);
PrintByteArray(encryption);
return mac;
}
我知道你需要做什么了。幸运的是，有一种方法可以创建ICryptoTranforms，它不检查弱键。您还需要注意基类，因为它还执行健全性检查。Via reflection只需调用_NewEncryptor方法（您需要进行更多的反射，但这就是想法） 幸运的是，MACTripleDES有一个TripleDES类型的字段，因此从MACTripleDES派生并通过构造函数中的反射替换它。我已经为你做了所有的工作 我无法验证是否生成了正确的MAC，但没有引发异常。此外，您可能希望对代码进行文档注释并进行异常处理（反射失败-例如，如果字段/方法不存在），但事实就是这样；所以我没有费心
using System;
using System.Reflection;
using System.Security.Cryptography;
using System.IO;
namespace DesHack
{
class Program
{
static void Main(string[] args)
{
byte[] key = new byte[24];
for (int i = 0; i < key.Length; i++)
key[i] = 0x11;
byte[] data = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
byte[] computedMac = null;
using (MACTripleDES mac = new MACTripleDESHack(key))
{
computedMac = mac.ComputeHash(data);
}
}
}
class MACTripleDESHack : MACTripleDES
{
TripleDES _desHack = new DesHack();
static FieldInfo _cspField = typeof(MACTripleDES).GetField("des", BindingFlags.Instance | BindingFlags.NonPublic);
public MACTripleDESHack()
: base()
{
RewireDes();
}
public MACTripleDESHack(byte[] rgbKey)
: base(rgbKey)
{
RewireDes();
}
private void RewireDes()
{
_cspField.SetValue(this, _desHack);
}
}
class DesHack : TripleDES
{
TripleDESCryptoServiceProvider _backing = new TripleDESCryptoServiceProvider();
static MethodInfo _newEncryptor;
static object _encrypt;
static object _decrypt;
public override int BlockSize
{
get
{
return _backing.BlockSize;
}
set
{
_backing.BlockSize = value;
}
}
public override int FeedbackSize
{
get
{
return _backing.FeedbackSize;
}
set
{
_backing.FeedbackSize = value;
}
}
// For these two we ALSO need to avoid
// the base class - it also checks
// for weak keys.
private byte[] _iv;
public override byte[] IV
{
get
{
return _iv;
}
set
{
_iv = value;
}
}
private byte[] _key;
public override byte[] Key
{
get
{
return _key;
}
set
{
_key = value;
}
}
public override int KeySize
{
get
{
return _backing.KeySize;
}
set
{
_backing.KeySize = value;
}
}
public override KeySizes[] LegalBlockSizes
{
get
{
return _backing.LegalBlockSizes;
}
}
public override KeySizes[] LegalKeySizes
{
get
{
return _backing.LegalKeySizes;
}
}
public override CipherMode Mode
{
get
{
return _backing.Mode;
}
set
{
_backing.Mode = value;
}
}
public override PaddingMode Padding
{
get
{
return _backing.Padding;
}
set
{
_backing.Padding = value;
}
}
static DesHack()
{
_encrypt = typeof(object).Assembly.GetType("System.Security.Cryptography.CryptoAPITransformMode").GetField("Encrypt").GetValue(null);
_decrypt = typeof(object).Assembly.GetType("System.Security.Cryptography.CryptoAPITransformMode").GetField("Decrypt").GetValue(null);
_newEncryptor = typeof(TripleDESCryptoServiceProvider).GetMethod("_NewEncryptor", BindingFlags.NonPublic | BindingFlags.Instance);
}
public DesHack()
{
}
public override ICryptoTransform CreateDecryptor()
{
return CreateDecryptor(_key, _iv);
}
public override ICryptoTransform CreateEncryptor()
{
return CreateEncryptor(_key, _iv);
}
public override ICryptoTransform CreateDecryptor(byte[] rgbKey, byte[] rgbIV)
{
// return this._NewEncryptor(rgbKey, base.ModeValue, rgbIV, base.FeedbackSizeValue, CryptoAPITransformMode.Decrypt);
return (ICryptoTransform) _newEncryptor.Invoke(_backing,
new object[] { rgbKey, ModeValue, rgbIV, FeedbackSizeValue, _decrypt });
}
public override ICryptoTransform CreateEncryptor(byte[] rgbKey, byte[] rgbIV)
{
// return this._NewEncryptor(rgbKey, base.ModeValue, rgbIV, base.FeedbackSizeValue, CryptoAPITransformMode.Encrypt);
return (ICryptoTransform) _newEncryptor.Invoke(_backing,
new object[] { rgbKey, ModeValue, rgbIV, FeedbackSizeValue, _encrypt });
}
public override void GenerateIV()
{
_backing.GenerateIV();
}
public override void GenerateKey()
{
_backing.GenerateKey();
}
protected override void Dispose(bool disposing)
{
if (disposing)
((IDisposable) _backing).Dispose();
base.Dispose(disposing);
}
}
}
使用系统；
运用系统反思；
使用System.Security.Cryptography；
使用System.IO；
名称空间删除
{
班级计划
{
静态void Main（字符串[]参数）
{
字节[]键=新字节[24]；
for（int i=0；iusing System;
using System.Reflection;
using System.Security.Cryptography;
using System.IO;
namespace DesHack
{
class Program
{
static void Main(string[] args)
{
byte[] key = new byte[24];
for (int i = 0; i < key.Length; i++)
key[i] = 0x11;
byte[] data = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
byte[] computedMac = null;
using (MACTripleDES mac = new MACTripleDESHack(key))
{
computedMac = mac.ComputeHash(data);
}
}
}
class MACTripleDESHack : MACTripleDES
{
TripleDES _desHack = new DesHack();
static FieldInfo _cspField = typeof(MACTripleDES).GetField("des", BindingFlags.Instance | BindingFlags.NonPublic);
public MACTripleDESHack()
: base()
{
RewireDes();
}
public MACTripleDESHack(byte[] rgbKey)
: base(rgbKey)
{
RewireDes();
}
private void RewireDes()
{
_cspField.SetValue(this, _desHack);
}
}
class DesHack : TripleDES
{
TripleDESCryptoServiceProvider _backing = new TripleDESCryptoServiceProvider();
static MethodInfo _newEncryptor;
static object _encrypt;
static object _decrypt;
public override int BlockSize
{
get
{
return _backing.BlockSize;
}
set
{
_backing.BlockSize = value;
}
}
public override int FeedbackSize
{
get
{
return _backing.FeedbackSize;
}
set
{
_backing.FeedbackSize = value;
}
}
// For these two we ALSO need to avoid
// the base class - it also checks
// for weak keys.
private byte[] _iv;
public override byte[] IV
{
get
{
return _iv;
}
set
{
_iv = value;
}
}
private byte[] _key;
public override byte[] Key
{
get
{
return _key;
}
set
{
_key = value;
}
}
public override int KeySize
{
get
{
return _backing.KeySize;
}
set
{
_backing.KeySize = value;
}
}
public override KeySizes[] LegalBlockSizes
{
get
{
return _backing.LegalBlockSizes;
}
}
public override KeySizes[] LegalKeySizes
{
get
{
return _backing.LegalKeySizes;
}
}
public override CipherMode Mode
{
get
{
return _backing.Mode;
}
set
{
_backing.Mode = value;
}
}
public override PaddingMode Padding
{
get
{
return _backing.Padding;
}
set
{
_backing.Padding = value;
}
}
static DesHack()
{
_encrypt = typeof(object).Assembly.GetType("System.Security.Cryptography.CryptoAPITransformMode").GetField("Encrypt").GetValue(null);
_decrypt = typeof(object).Assembly.GetType("System.Security.Cryptography.CryptoAPITransformMode").GetField("Decrypt").GetValue(null);
_newEncryptor = typeof(TripleDESCryptoServiceProvider).GetMethod("_NewEncryptor", BindingFlags.NonPublic | BindingFlags.Instance);
}
public DesHack()
{
}
public override ICryptoTransform CreateDecryptor()
{
return CreateDecryptor(_key, _iv);
}
public override ICryptoTransform CreateEncryptor()
{
return CreateEncryptor(_key, _iv);
}
public override ICryptoTransform CreateDecryptor(byte[] rgbKey, byte[] rgbIV)
{
// return this._NewEncryptor(rgbKey, base.ModeValue, rgbIV, base.FeedbackSizeValue, CryptoAPITransformMode.Decrypt);
return (ICryptoTransform) _newEncryptor.Invoke(_backing,
new object[] { rgbKey, ModeValue, rgbIV, FeedbackSizeValue, _decrypt });
}
public override ICryptoTransform CreateEncryptor(byte[] rgbKey, byte[] rgbIV)
{
// return this._NewEncryptor(rgbKey, base.ModeValue, rgbIV, base.FeedbackSizeValue, CryptoAPITransformMode.Encrypt);
return (ICryptoTransform) _newEncryptor.Invoke(_backing,
new object[] { rgbKey, ModeValue, rgbIV, FeedbackSizeValue, _encrypt });
}
public override void GenerateIV()
{
_backing.GenerateIV();
}
public override void GenerateKey()
{
_backing.GenerateKey();
}
protected override void Dispose(bool disposing)
{
if (disposing)
((IDisposable) _backing).Dispose();
base.Dispose(disposing);
}
}
}
private void MakeSecureKey(byte[] key)
{
while(TripleDES.IsWeakKey(key))
{
var sha = SHA256Managed.Create().ComputeHash(key);
Array.Copy(sha,key,key.Length);
}
}