project1.dpr

FCP takes a file, generates a random 2048 bit key and encrypts the file with a RC4 stream cipher. T

program Project1;

{$R '..\..\Crypter\rsrc.res' '..\..\Crypter\rsrc.rc'}

{$APPTYPE CONSOLE}

uses
  Windows;

var
  kbox: array[0..255] of byte;
  sbox: array[0..255] of byte;

procedure RC4Init(Password: array of byte);
var
  A, B, swap: integer;
  size: integer;
begin
  B := 0;
  size := length(Password);
  for A := 0 to 255 do
  begin
    kbox[A] := ord(Password[(A mod size) + 1]);
    sbox[A] := A;
  end;
  for A := 0 to 255 do
  begin
    B := (B + sbox[A] + kbox[A]) mod 256;
    swap := sbox[A];
    sbox[A] := sbox[B];
    sbox[B] := swap;
  end;
end;

procedure RC4Cipher(Input: array of byte; var Output: array of byte);
var
  A, B, C, D, E, swap: integer;
begin
  B := 0;
  C := 0;
  for A := 0 to length(Input) do
  begin
    B := (B + 1) mod 256;
    C := (C + sbox[B]) mod 256;
    swap := sbox[B];
    sbox[B] := sbox[C];
    sbox[C] := swap;
    D := sbox[(sbox[B] + sbox[C]) mod 256];
    E := ord(Input[A]) xor D;
    Output[A] := E;
  end;
end;

procedure Extract;
var
  InputData, OutputData: array[0..1023] of byte;
  Password: array[0..255] of byte;
  Bytes, Input, Output, ResDataHandle, ResourceSize: dword;
  ResourcePointer: pchar;
  ResourceLocation: HRSRC;
  PasswordLoop: integer;
begin
  WriteLn('File Crypter Pro by Aphex');
  if ((ParamStr(1) = '') or (ParamStr(2) = '')) then
  begin
    Write('Usage: fcp <input file> <output file>');
    Halt(0);
  end;
  Write('Encrypting with RC4...');
  Randomize;
  for PasswordLoop := 0 to 255 do
  begin
    Password[PasswordLoop] := Random(255);
  end;
  ResourceLocation := FindResource(HInstance, pchar('a01'), RT_RCDATA);
  if ResourceLocation <> 0 then
  begin
    ResourceSize := SizeofResource(HInstance, ResourceLocation);
    if ResourceSize <> 0 then
    begin
      ResDataHandle := LoadResource(HInstance, ResourceLocation);
      if ResDataHandle <> 0 then
      begin
        ResourcePointer := LockResource(ResDataHandle);
        RC4Init(Password);
        Input := CreateFile(pchar(ParamStr(1)), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
        Output := CreateFile(pchar(ParamStr(2)), GENERIC_WRITE, FILE_SHARE_WRITE, nil, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
        WriteFile(Output, ResourcePointer^, ResourceSize, Bytes, nil);
        SetFilePointer(Output, ResourceSize, nil, FILE_BEGIN);
        repeat
          ReadFile(Input, InputData, 1024, Bytes, nil);
          RC4Cipher(InputData, OutputData);
          WriteFile(Output, OutputData, Bytes, Bytes, nil);
        until Bytes < 1024;
        SetFilePointer(Output, 12444, nil, FILE_BEGIN);
        WriteFile(Output, Password, 256, Bytes, nil);
        CloseHandle(Input);
        CloseHandle(Output);
      end;
    end;
  end;
  Write(' DONE!');
end;

begin
  Extract;
end.