format PE console 4.0
include 'win32a.inc'
jmp a0
data import
;krnlname:
 library kernel32,'KERNEL32.DLL'
 import kernel32,\
    CloseHandle,'CloseHandle',\
    CreateFile,'CreateFileA',\
    FreeEnvironmentStrings,'FreeEnvironmentStringsA',\
    FreeLibrary,'FreeLibrary',\
    GetCurrentProcessId,'GetCurrentProcessId',\
    GetCurrentThreadId,'GetCurrentThreadId',\
    GetDiskFreeSpaceEx,'GetDiskFreeSpaceExA',\
    GetEnvironmentStrings,'GetEnvironmentStringsA',\
    GetProcAddress,'GetProcAddress',\
    GetStdHandle,'GetStdHandle',\
    GetSystemTime,'GetSystemTime',\
    GetSystemTimeAsFileTime,'GetSystemTimeAsFileTime',\
    GetTickCount,'GetTickCount',\
    GlobalMemoryStatus,'GlobalMemoryStatus',\
    LoadLibrary,'LoadLibraryA',\
    ReadFile,'ReadFile',\
    VirtualAlloc,'VirtualAlloc',\
    VirtualFree,'VirtualFree',\
    WriteFile,'WriteFile',\
    ExitProcess,'ExitProcess'
end data

RandSeed    db 20 dup 0
Rand_SysData    db 64 dup 0
Rand_Context    db 104 dup 0
ARC_Context db 258 dup 0
Rand_KRNL   db 'KERNEL32.DLL',0
;krnladdr        dd krnlname
Rand_GMSE   db 'GlobalMemoryStatusEx',0
Rand_HMOD   dd 0
stdout      dd 0
bittable    dd 0
tmptable    dd 0
blocksize   dw 4 ; VERY IMPORTANT - must be divisable by 4
sblocksize  dd 0
powermod    db $01,$AB,$CD,$B7,$39,$A3,$C5,$EF,$F1,$1B,$3D,$A7,$29,$13,$35,$DF ;PowerMod[i*2+1,-1,256]
        db $E1,$8B,$AD,$97,$19,$83,$A5,$CF,$D1,$FB,$1D,$87,$09,$F3,$15,$BF ; i.e. if we want to calculate PowerMod[x,-1,256] where x is odd number between 1 and 255,
        db $C1,$6B,$8D,$77,$F9,$63,$85,$AF,$B1,$DB,$FD,$67,$E9,$D3,$F5,$9F ; shr eax,1
        db $A1,$4B,$6D,$57,$D9,$43,$65,$8F,$91,$BB,$DD,$47,$C9,$B3,$D5,$7F ; mov eax,[powermod+eax]
        db $81,$2B,$4D,$37,$B9,$23,$45,$6F,$71,$9B,$BD,$27,$A9,$93,$B5,$5F
        db $61,$0B,$2D,$17,$99,$03,$25,$4F,$51,$7B,$9D,$07,$89,$73,$95,$3F
        db $41,$EB,$0D,$F7,$79,$E3,$05,$2F,$31,$5B,$7D,$E7,$69,$53,$75,$1F
        db $21,$CB,$ED,$D7,$59,$C3,$E5,$0F,$11,$3B,$5D,$C7,$49,$33,$55,$FF
memerr      db 'Memory allocation error',13,10
memerrl = $-memerr
forwardname db 'forward.bin',0
backwardname    db 'backward.bin',0
;here subs
noconst = 1
include 'sha1.inc'
include 'ISCrypt.inc'

a0:
    mov ax,[blocksize]
    mul ax
    xchg    dx,ax
    shl eax,16
    mov ax,dx
    mov [sblocksize],eax
    stdcall SHA1Reset,Rand_Context
    invoke  GetCurrentProcessId
    mov dword[Rand_SysData],eax
    stdcall SHA1Input,Rand_Context,Rand_SysData,4
    invoke  GetCurrentThreadId
    mov dword[Rand_SysData],eax
    stdcall SHA1Input,Rand_Context,Rand_SysData,4
    invoke  GetDiskFreeSpaceEx,0,Rand_SysData,Rand_SysData+8,Rand_SysData+16
    stdcall SHA1Input,Rand_Context,Rand_SysData,24
    invoke  GetEnvironmentStrings
    mov dword[Rand_SysData],eax
    Rand_for1begin:
    cmp byte[eax],0
    jz  Rand_for1end
    @@:
    cmp byte[eax],0
    jz  @f
    inc eax
    jmp @b
    @@:
    inc eax
    jmp Rand_for1begin
    Rand_for1end:
    sub eax,dword[Rand_SysData]
    stdcall SHA1Input,Rand_Context,dword[Rand_SysData],eax
    invoke  FreeEnvironmentStrings,dword[Rand_SysData]
    invoke  GetSystemTime,Rand_SysData
    stdcall SHA1Input,Rand_Context,Rand_SysData,16
    invoke  GetSystemTimeAsFileTime,Rand_SysData
    stdcall SHA1Input,Rand_Context,Rand_SysData,8
    invoke  GetTickCount
    mov dword[Rand_SysData],eax
    stdcall SHA1Input,Rand_Context,Rand_SysData,4
    invoke  LoadLibrary,Rand_KRNL
    ;invoke  LoadLibrary,krnlname+$28
    or  eax,eax
    jz  Rand_nolib
    mov [Rand_HMOD],eax
    invoke  GetProcAddress,[Rand_HMOD],Rand_GMSE
    or  eax,eax
    jz  Rand_noproc
    mov dword[Rand_SysData],64
    stdcall eax,Rand_SysData
    stdcall SHA1Input,Rand_Context,Rand_SysData,64
    jmp @f
    Rand_noproc:
    invoke  FreeLibrary,[Rand_HMOD]
    Rand_nolib:
    mov dword[Rand_SysData],32
    invoke  GlobalMemoryStatus,Rand_SysData
    stdcall SHA1Input,Rand_Context,Rand_SysData,32
@@:
    stdcall SHA1Result,Rand_Context,RandSeed
    stdcall ArcFourInit,ARC_Context,RandSeed,20
    stdcall ArcFourCrypt,ARC_Context,0,0,1000
    ; now RandSeed is initialised
    invoke  GetStdHandle,$FFFFFFF5
    mov [stdout],eax

    invoke  VirtualAlloc,0,[sblocksize],MEM_COMMIT,PAGE_READWRITE
    mov [bittable],eax
    or  eax,eax
    jnz @f
pmemerr:
    invoke  WriteFile,[stdout],memerr,memerrl,RandSeed,0
    jmp exit
@@:
    invoke  VirtualAlloc,0,[sblocksize],MEM_COMMIT,PAGE_READWRITE
    mov [tmptable],eax
    or  eax,eax
    jz  pmemerr

    ; now memory is allocated
    cld
    mov ebp,[tmptable]
    movzx   edx,[blocksize]
mainloop:   ;ok=ebx, n=edx, i=esi, j=edi,
    mov ecx,[sblocksize]
    stdcall ArcFourCrypt,ARC_Context,0,[bittable],ecx   ;bittable = Table[RandomInteger[], {i, n}, {j, n}];
    ; now matrix is filled, check - it's det must be odd
    shr ecx,2
    mov esi,[bittable]
    mov edi,ebp
    rep movsd   ;tmptable = bittable;
    xor ebx,ebx
    inc ebx ;ok = True;
    xor esi,esi ;i = 1; because 0..n-1
lab2:
    lea eax,[edx-1] ; because 0..n-1
    cmp esi,eax
    je  lab3    ;If[i == n, Goto[lab3]];
    mov ecx,edx
    mov eax,esi
    mul cx
    xchg    dx,ax
    shl eax,16
    mov ax,dx
    mov edx,ecx
    add eax,ebp
    mov al,byte[eax+esi]
    bt  eax,0
    jc  lab4    ;If[tmptable[[i, i]] != 0, Goto[lab4]];
    xor ebx,ebx ;ok = False;
    mov edi,esi
    inc edi ;j = i + 1;
lab6:
    cmp edi,edx
    je  lab5    ;If[j > n, Goto[lab5]];
    mov ecx,edx
    mov eax,edi
    mul cx
    xchg    dx,ax
    shl eax,16
    mov ax,dx
    mov edx,ecx
    add eax,ebp
    mov al,byte[eax+esi]
    bt  eax,0
    jnc lab7    ;If[tmptable[[j, i]] != 1, Goto[lab7]];
    push    esi
    push    edi
    mov ecx,edx
    mov eax,esi
    mul cx
    xchg    dx,ax
    shl eax,16
    mov ax,dx
    mov esi,eax ;now esi=i*n
    mov eax,edi
    mul cx
    xchg    dx,ax
    shl eax,16
    mov ax,dx
    mov edi,eax ;now edi=j*n
    mov edx,ecx
    shr edx,2
    xor ecx,ecx
@@:
    xchg    eax,[ebp+esi]
    xchg    eax,[ebp+edi]
    xchg    eax,[ebp+esi]
    inc ecx
    add ebp,4
    cmp ecx,edx
    jne @b
    mov ebp,[tmptable]
    movzx   edx,[blocksize]
    pop edi
    pop esi  ;tmpline = tmptable[[i]];tmptable[[i]] = tmptable[[j]];tmptable[[j]] = tmpline;
    xor ebx,ebx
    inc ebx ;ok = True;
    jmp lab5
lab7:
    inc edi ;j++;
    jmp lab6
lab5:
    or  ebx,ebx
    jz  lab3    ;If[! ok, Goto[lab3]];
lab4:
    mov edi,esi
    inc edi ;j = i + 1;
lab8:
    cmp edi,edx
    je  lab9    ;If[j > n, Goto[lab9]];
    mov ecx,edx
    mov eax,edi
    mul cx
    xchg    dx,ax
    shl eax,16
    mov ax,dx
    mov edx,ecx
    add eax,ebp
    mov al,byte[eax+esi]
    bt  eax,0
    jnc lab10    ;If[tmptable[[j, i]] != 1, Goto[lab10]];
    push    esi
    push    edi
    mov ecx,edx
    mov eax,esi
    mul cx
    xchg    dx,ax
    shl eax,16
    mov ax,dx
    mov esi,eax ;now esi=i*n
    mov eax,edi
    mul cx
    xchg    dx,ax
    shl eax,16
    mov ax,dx
    mov edi,eax ;now edi=j*n
    mov edx,ecx
    shr edx,2
    xor ecx,ecx
@@:
    mov eax,[edi+ebp]
    xor eax,[esi+ebp]
    mov [edi+ebp],eax
    inc ecx
    add ebp,4
    cmp ecx,edx
    jne @b
    mov ebp,[tmptable]
    movzx   edx,[blocksize]
    pop edi
    pop esi  ;tmptable[[j]] = BitXor[tmptable[[i]], tmptable[[j]]];
lab10:
    inc edi ;j++;
    jmp lab8
lab9:
    inc esi ;i++;
    jmp lab2
lab3:
    or  ebx,ebx
    jz  mainloop    ;If[! ok, Goto[lab1]];
    mov eax,[sblocksize]
    dec eax
    movzx   eax,byte[ebp+eax]
    bt  eax,0
    jnc mainloop
    ;now we must check bittable for zeros and if there any, change them to random even number
    mov esi,[bittable]
    xor ecx,ecx
    mov edx,[sblocksize]
dezero_loop:
    movzx   eax,byte[esi]
    or  eax,eax
    jnz @f
    stdcall ArcFourCrypt,ARC_Context,eax,esi,1
    and byte[esi],$FE
    jmp dezero_loop
@@:
    inc esi
    inc ecx
    cmp ecx,edx
    jnz dezero_loop
    invoke  CreateFile,forwardname,GENERIC_WRITE,0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL
    mov [Rand_HMOD],eax
    invoke  WriteFile,eax,[bittable],[sblocksize],RandSeed,NULL
    invoke  CloseHandle,[Rand_HMOD]
    ;calculate inverse matrix
    ;bittable contains keytable, there will be identity matrix
    ;tmptable will contain inverse matrix
    mov ecx,[sblocksize]
    xor eax,eax
    mov edi,[tmptable]
    rep stosd



    invoke  CreateFile,backwardname,GENERIC_WRITE,0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL
    mov [Rand_HMOD],eax
    invoke  WriteFile,eax,[tmptable],[sblocksize],RandSeed,NULL
    invoke  CloseHandle,[Rand_HMOD]
exit:   invoke  ExitProcess,0