2016 "Anheng Cup" National University Network Information Security management operation and maintenance Challenge competition _re200
64 bits. NET Program
Run:
Parameter Check Reflector analysis: f= "incorrect"----loc.2i= "parameter error"----loc.3p= "? #?? # #? #?? #?##? ?# ?#?#?#? #?# ?#?? # #?# "l_0005 ... l_000a stloc.0 l_0046 ldloc.0l_0047 .... l_004c ldc.i4.8l_004d beq.s l_0056 Check whether the number of parameters is 8, equal skip output "parameter error" STR6 hold numeric characters, reverse conversion to digital type = =0x145d526db9faad8, sequential decimal conversion = =00011110303731719str6= "00011110303731719" by If (srt3!= str5.reverse ()) jmp L_015ASTR5 str3 in reverse order str5= " Nttdffcttrcvrhrghfa "p="? #?? # #??? #?##? ?# ?#?#?#? #?# ?#?? # #?# "?-> character #-> Digital input: n0t T00 d1ff1c11t t0 r3c0v3r 7h3 r1gh7 f1a9
Get flag:eis{n0t_t00_d1ff1c11t_t0_r3c0v3r_7h3_r1gh7_f1a9} Il compilation notes:. Method PublicStaticvoid
Main() CIL managed
{
. Custominstancevoid [Mscorlib]system.stathreadattribute::.ctor ()
. EntryPoint
. Maxstack5
. LocalsInit(
[0]class[mscorlib] System.Collections.ObjectModel.ReadOnlyCollection ' 1<string>
Onlys,
[1] UInt64
Num,
[2] String
Str,
[3] String
str2,
[4] String
STR3,
[5] string[]
Strarray,
[6] String
STR4,
[7] String
STR5,
[8] String
STR6,
[9] Int32
num2,
[Ten] Int32
num3,
[ One] Int32
num4,
[ A] Int32
NUM5,
[ -] Char
CH)
L_0000:callclassChkflag. My.myapplication Chkflag. My.myproject::get_application () L_0005:callvirtinstanceclass[mscorlib] System.Collections.ObjectModel.ReadOnlyCollection ' 1<string> [Microsoft.VisualBasic] Microsoft.visualbasic.applicationservices.consoleapplicationbase::get_commandlineargs () l_000a:stloc.0 Onlys Storage Parameters L_000b:ldc.i80x145d526db9faad8L_0014:stloc.1//num=0x145d526db9faad8 L_0015:callclass[mscorlib] System.Resources.ResourceManager Chkflag. My.resources.resources::get_resourcemanager ()
L_001a:ldstr"F"L_001f:callvirtinstancestring [Mscorlib]system.resources.resourcemanager::getstring (String) l_0024:stloc.2 Str= "Incorrect" L_0025:callclass[mscorlib] System.Resources.ResourceManager Chkflag. My.resources.resources::get_resourcemanager ()
L_002a:ldstr$id
L_002f:callvirtinstancestring [Mscorlib]system.resources.resourcemanager::getstring (String)
L_0034:STLOC.3//str2= "Parameter Error"
L_0035:callclassChkflag. My.myapplication Chkflag. My.myproject::get_application ()
L_003a:callvirtinstanceclass[Microsoft.VisualBasic] Microsoft.VisualBasic.ApplicationServices.AssemblyInfo [Microsoft.VisualBasic] Microsoft.visualbasic.applicationservices.applicationbase::get_info ()
L_003f:callvirtinstancestring [Microsoft.visualbasic]microsoft.visualbasic.applicationservices.assemblyinfo::get_description () L_0044: Stloc.s STR3//STR3 Storage description Information//.custom instance void [Mscorlib]system.reflection.assemb Lydescriptionattribute::.ctor (String) = {string (' Afhgrhrvcrttcffdttn ')}//str3= "Afhgrhrvcrttcffdttn" l_0046: ldloc.0 L_0047:callvirtinstanceInt32 [Mscorlib]system.collections.objectmodel.readonlycollection ' 1<string>::get_count () l_004c:ldc.i4.8 L_ 004d:beq.s l_0056//if (count==8) jmp l_0056 l_004f:ldloc.3 L_0050:call vo ID [Mscorlib]system.console::writeline (string)//print "parameter Error" L_0055:ret
L_0056:callclass[mscorlib] System.Resources.ResourceManager Chkflag. My.resources.resources::get_resourcemanager ()
L_005b:ldstr"P"
L_0060:callvirtinstancestring [Mscorlib]system.resources.resourcemanager::getstring (String) l_0065:ldc.i4.1 L_0066:newarr Char L_006b:dup
l_006c:ldc.i4.0 L_006D:LDC.I4.S0x20L_006f:stelem.i2 L_0070:callvirtinstanceString[] [Mscorlib]system.string::split (char[]) l_0075:stloc.s strarray//char strarray[]=p l_0077:ldloc.0
L_0078:callvirtinstanceInt32 [Mscorlib]system.collections.objectmodel.readonlycollection ' 1<string>::get_count ()
l_007d:ldc.i4.1 L_007e:sub.ovf L_007f:stloc.s num2//num2=len ((onlys)-1 l_0081: ldc.i4.0
L_0082:stloc.s num3//num3=0
L_0084:BR.S l_00a8//jmp l_00a8
l_0086:ldloc.0 L_0087:ldloc.s num3 L_0089:callvirtinstance!0 [Mscorlib]system.collections.objectmodel.readonlycollection ' 1<string>::get_item (Int32)//onlys[num3] L_ 008e:ldloc.s Strarray
L_0090:ldloc.s num3
L_0092:ldelem.ref
l_0093:ldc.i4.0 l_0094:call bool [microsoft.visualbasic]microsoft.visualbasic.compilerservices.likeoperator:: Likestring (String, String,ValueType[Microsoft.VisualBasic] Microsoft.VisualBasic.CompareMethod)//comparison type l_0099:brtrue.s l_00a2 l_009b:ldloc.2 l_009c:call void [Mscorli B]system.console::writeline (String)//print "Incorrect" L_00a1:ret
L_00a2:ldloc.s num3
l_00a4:ldc.i4.1 L_00a5:add.ovf l_00a6:stloc.s num3//num3+=1 l_00a8:ldloc.s num3
L_00aa:ldloc.s num2
L_00AC:BLE.S l_0086 if (num3<=num2) jmp l_0086
L_00ae:ldstr""
l_00b3:ldloc.0
L_00b4:call string [Mscorlib]system.string::join (String,class[mscorlib] System.Collections.Generic.IEnumerable ' 1<string>)
L_00b9:stloc.s STR4
L_00bb:ldstr""
L_00c0:stloc.s STR5
L_00c2:ldstr""
L_00c7:stloc.s STR6
L_00c9:ldloc.s STR4
L_00cb:callvirtinstanceInt32 [Mscorlib]system.string::get_length ()
l_00d0:ldc.i4.1 L_00d1:sub.ovf l_00d2:stloc.s num4//num4=len (STR4) l_00d4:ldc.i4.0 L_00d5:stl Oc.s num5//num5=0 l_00d7:br.s l_0115//jmp l_0115 l_00d9:ldloc.s STR4
L_00db:ldloc.s NUM5
L_00dd:callvirtinstanceChar [Mscorlib]system.string::get_chars (Int32)
L_00e2:stloc.s CH//CH=STR4[NUM5]
L_00E4:LDLOC.S CH l_00e6:call bool [Mscorlib]system.char::isdigit (Char) l_00eb:brfalse.s l_00ff//if ch not decimal Digital JMP l_00ff L_00ed:ldloc.s STR6
L_00ef:ldloc.s CH
L_00f1:call string [microsoft.visualbasic]microsoft.visualbasic.compilerservices.conversions::tostring (char)
L_00f6:call string [Mscorlib]system.string::concat (String, String)
L_00FB:STLOC.S STR6//STR6 Storing digital elements
L_00FD:BR.S l_010f
L_00ff:ldloc.s STR5
L_0101:ldloc.s CH
L_0103:call string [microsoft.visualbasic]microsoft.visualbasic.compilerservices.conversions::tostring (char)
L_0108:call string [Mscorlib]system.string::concat (String, String) L_010d:stloc.s STR5//STR5 holds character elements L_010f:ldloc.s NUM5
l_0111:ldc.i4.1
L_0112:add.ovf
L_0113:stloc.s NUM5
l_0115: ldloc.s num5 l_0117: ldloc.s num4 l_0119: BLE.S&NBSP;L_00D9 //if (NUM5<=NUM4) jmp l_00 d9 l_011b: ldloc.s str6 l_011d: call string [ Microsoft.visualbasic]microsoft.visualbasic.strings::strreverse (String) l_0122: call Uint64 [mscorlib]system.uint64::P Arse (String) //convert character data string to digital l_0127: ldloc.1 l_0128: bne.un.s l_015a //if (Num!=int (STR6)) & nbsp num=91713730301111000 l_012a: ldloc.s str5 L_012c: call string [microsoft.visualbasic]microsoft.visualbasic.strings:: StrReverse (String) str5.reverse () l_0131: ldloc.s str3 L_0133: callvirt instancebool [Mscorlib]system.string::equals (String) l_0138:brfalse.s l_015a//if (srt3!= str5.reverse ()) jmp l_015a L_013a:ldstr"eis{"
L_013f:ldstr"_"
l_0144:ldloc.0
L_0145:call string [Mscorlib]system.string::join (String,class[mscorlib] System.Collections.Generic.IEnumerable ' 1<string>)
L_014a:ldstr"}"
L_014f:call string [Mscorlib]system.string::concat (String, String, String)
L_0154:call void [Mscorlib]system.console::writeline (String)
L_0159:ret
L_015a:ldloc.2
L_015b:call void [Mscorlib]system.console::writeline (String)
L_0160:ret} 00011110303731719 NTTDFFCTTRCVRHRGHFA
The first one. NET program Reverse
