请教解密算法

[bensharp]

“123”经过加密之后是“R2AKd+aZ0K4=”

请教高手问怎么样才可以知道是使用什么加密算法的呢？

[jzywh]

貌似是Base64

System.Text.Encoding.Default.GetString(Convert.FromBase64String("R2AKd+aZ0K4="))


也可能是SHA1

如果是SHA1的话就没办法解密了

[bensharp]

楼上说的Base64和SHA1我都试过了，123加密之后都不是那样的密码字符串

[bensharp]

刚才用IL反编译看了一下
那应该是对称加密，在用key加密之后，还来1次base64加密～～

反编译后显示结构
.class public auto ansi
arrDESIV : private unit8[]
arrDESKey : private unit8[]
.ctor : void()
Decrypt : string(string)
Encrypt : string(string)



Encrypt方法具体描述
.method public instance string Encrypt(string m_Need_Encode_String) cil managed
{
// 代码大小 102 (0x66)
.maxstack 4
.locals init (string V_0,
class [mscorlib]System.Security.Cryptography.CryptoStream V_1,
class [mscorlib]System.Security.Cryptography.DESCryptoServiceProvider V_2,
class [mscorlib]System.IO.MemoryStream V_3,
class [mscorlib]System.IO.StreamWriter V_4)
IL_0000: nop
IL_0001: newobj instance void [mscorlib]System.Security.Cryptography.DESCryptoServiceProvider::.ctor()
IL_0006: stloc.2
IL_0007: newobj instance void [mscorlib]System.IO.MemoryStream::.ctor()
IL_000c: stloc.3
IL_000d: ldloc.3
IL_000e: ldloc.2
IL_000f: ldarg.0
IL_0010: ldfld uint8[] PantoSchool.XT.Accounts.Business.DECEncrypt::arrDESKey
IL_0015: ldarg.0
IL_0016: ldfld uint8[] PantoSchool.XT.Accounts.Business.DECEncrypt::arrDESIV
IL_001b: callvirt instance class [mscorlib]System.Security.Cryptography.ICryptoTransform [mscorlib]System.Security.Cryptography.DESCryptoServiceProvider::CreateEncryptor(uint8[],
uint8[])
IL_0020: ldc.i4.1
IL_0021: newobj instance void [mscorlib]System.Security.Cryptography.CryptoStream::.ctor(class [mscorlib]System.IO.Stream,
class [mscorlib]System.Security.Cryptography.ICryptoTransform,
valuetype [mscorlib]System.Security.Cryptography.CryptoStreamMode)
IL_0026: stloc.1
IL_0027: ldloc.1
IL_0028: newobj instance void [mscorlib]System.IO.StreamWriter::.ctor(class [mscorlib]System.IO.Stream)
IL_002d: stloc.s V_4
IL_002f: ldloc.s V_4
IL_0031: ldarg.1
IL_0032: callvirt instance void [mscorlib]System.IO.StreamWriter::Write(string)
IL_0037: nop
IL_0038: ldloc.s V_4
IL_003a: callvirt instance void [mscorlib]System.IO.StreamWriter::Flush()
IL_003f: nop
IL_0040: ldloc.1
IL_0041: callvirt instance void [mscorlib]System.Security.Cryptography.CryptoStream::FlushFinalBlock()
IL_0046: nop
IL_0047: ldloc.3
IL_0048: callvirt instance void [mscorlib]System.IO.MemoryStream::Flush()
IL_004d: nop
IL_004e: ldloc.3
IL_004f: callvirt instance uint8[] [mscorlib]System.IO.MemoryStream::GetBuffer()
IL_0054: ldc.i4.0
IL_0055: ldloc.3
IL_0056: callvirt instance int64 [mscorlib]System.IO.MemoryStream::get_Length()
IL_005b: conv.ovf.i4
IL_005c: call string [mscorlib]System.Convert::ToBase64String(uint8[],
int32,
int32)
IL_0061: stloc.0
IL_0062: br.s IL_0064
IL_0064: ldloc.0
IL_0065: ret
} // end of method DECEncrypt::Encrypt




怎么样能还原到原来的算法呢？怎么样能推出他的key和iv的值呢？

[commandos]

可能是先md5在base64..

[bensharp]

看那IL反编译的内容就知道应该不是md5再base64了，有key跟iv，明显是可逆的加密

[aith1986]

应该是用KEY加密的

[深海之蓝]

你应该到 看雪学院 去问这个问题，那个论坛是专门弄 加密和解密的