I do not remember where I retrieved this code from, but it is available in the public domain....
Has anyone already got a PB version of this code?
If not, does someone have the ability to easily convert this to PB?
It's greek to me for the most part because it does the DOS screen and the encryption...and I can READ ASM but I cant' write it...
Scott
------------------
Scott
mailto:[email protected][email protected]</A>
Has anyone already got a PB version of this code?
If not, does someone have the ability to easily convert this to PB?
It's greek to me for the most part because it does the DOS screen and the encryption...and I can READ ASM but I cant' write it...
Scott
Code:
.radix 16 ; RIJNDAEL cipher program (DOS) Using ; CFB block chaining, supporting 128, ; 192, And 256-Bit blocks And keys And ; UC file Name (repeated) As IV ; This program incorporates a Davies- ; Meyer Type key hash With 00 As IV ; The Input key length is 2*blockbytes, ; which more closely matches entropy ; of user Input To that of cipher ; This version can be assembled On the ; A86 shareware assembler, available ; From [url="http://www.eji.com"]www.eji.com[/url] And runs On Any '86 ; Copyright April 12, 2000 by ; Robert G. Durnal ([email protected]) ; Released For free use by anyone! ; Source posted under 'Unrestricted ; Source Code' license exception to ; EAR regulations ; Block Size In bits = 32 x NCOLS ; Key Size In bits = 32 x NKEYS NCOLS equ 8 ; May be 4, 6, Or 8 NKEYS equ 8 ; May be 4, 6, Or 8 KEYBYTES equ NKEYS*4 BLOCKBYTES equ NCOLS*4 READSIZE equ 0C000 DATABUF equ 1084 ; Value saves 1 Byte PWR_TAB equ 0E00 LOG_TAB equ 0F00 SBOX equ LOG_TAB CFBBUF equ PWR_TAB #If NCOLS GT NKEYS ROUNDS equ 6+NCOLS #Else ROUNDS equ 6+NKEYS #EndIf ; Routines For RIJNDAEL S-box creation ; derived From formulas In Dr. Brian ; Gladman's RIJNDAEL implementation ; First prepare Pwr And Log tables. ; ; For (i=0; p=1; i<256; ++i) ; { ; pwr_tab[i]=p; log_tab[p]=i; ; p=p^(p<<1)^(p&0x80?0x01b:0) ; } MAKETABLES: mov di,pwr_tab mov bp,di ; Save pointer To CFBBUF mov bh,log_tab/100 mov cx,100 inc ax ; DOS starts AX At 0000 MAKETABLOOP: mov bl,al xchg ax,di mov [bx],al ; Store Log value xchg ax,di stosb ; And Pwr value mov ah,al ; Compute Next Pwr Call xtime ; (p<<1)^(p&0x80?0x1b:0) Xor al,ah ; p^(p<<1)^(p&0x80?0x1b:0) Loop maketabloop ; Now use those tables To Create S-box ; OK To overwrite Log table. ; ; For (i=0; i<256; ++i) ; { ; p=(i?(pwr_tab[255-log_tab[i]]):0); ; q=p; ; q=(q>>7) | (q<<1); p^=q; ; q=(q>>7) | (q<<1); p^=q; ; q=(q>>7) | (q<<1); p^=q; ; q=(q>>7) | (q<<1); p^=q^0x63; ; sbx_tab[i]=p; ; } MAKESBOX: ; Starts With CX = 0 mov bx,bp ; --> PWR_TAB For XLAT db 0D6 ; Clears AL To start SBOXLOOP: ; AL = p, AH = q mov ah,al ; q=p mov ch,4 ; CX always 04xx here MAKES1: ; C formula For ROL q,1 rol ah,1 ; q=(q>>7) | (q<<1) Xor al,ah ; p ^= q dec ch jnz makes1 ; 4 times Xor al,63 ; Here CH always 00 stosb ; Store computed value mov al,[di] ; Get Next log_tab[i] Not al ; 255-log_tab[i] xlat ; pwr_tab[255-log_tab[i]] Loop sboxloop CHECKCMD: ; Check cmd Line syntax mov si,80 ; Default DTA location lodsw cmp al,4 ; Check For parameters jc exit1 lodsw Sub al,'+' ; Test for encrypt (+) jz getkey Add b[direction],al Sub al,2 ; Test For decrypt (-) jnz exit1 GETKEY: push si ; SI --> FileName In DTA mov dx,askforkey mov ah,9 ; Solicit via STDOUT Int 21 mov dl,keybuf Mod 100 mov ah,0A Int 21 ; Get key via STDIN mov ax,3 Int 10 ; Clear key From screen xchg si,dx ; SI --> KEYBUF DX = 0084 lodsb lodsb ; SI --> KEYARRAY xchg ax,di ; DI = Length of key Add di,si ; DI = CR In KEYARRAY mov cl,2*keybytes rep movsb ; Move more than enough mov di,bp ; CFBBUF mov cl,2*keybytes PUSHKEY: ; Push All key bytes dec si ; Push In reverse order mov al,[si] push ax ; Only AL will be used db 0D6 ; Zero AL by SALC stosb ; Clear CFBBUF this Loop Loop pushkey ; Sets 00 IV For hash HASHKEY: ; Hash the Input key mov cl,blockbytes mov di,bp POPKEY: ; Pop key Mat'l to CFBBUF pop ax stosb push bx ; BL always 00 here pop bx ; Overwrite key In stack cmp sp,0FFFC ; Restrict POPs ó PUSHs loopnz popkey EXPANDKEY: Call keysched ; Make key And encrypt mov di,bp mov cl,blockbytes/2 mov si,keyarray KEYCRYPT: ; Mix With original key mov ax,[di] Xor [si],ax movsw ; Dup In CFBBUF = New IV cmp si,keyarray+keybytes ; End of key? loopnz keycrypt cmp sp,0FFFC jnc endhash ; No more PUSHed Data inc cx Loop keycrypt-3 ; ð JCXNZ jmp hashkey EXIT1: ; Bad cmd Line Show usage mov si,offset usage Exit: ; Print Error messages via INT29 lodsb Int 29 Or al,al jnz Exit ret ; INT20 Exit via PSP 00 ENDHASH: Call keysched ; Final key schedule pop dx mov si,dx ; DX --> fname In DTA mov di,bp mov cl,blockbytes PARSEFNAME: ; Set into CFBBUF As IV lodsb And al,5F ; Quasi U/C, OK For IV stosb cmp b[si],20 ja parsefname mov [si],ch ; Make Asciiz In DTA mov si,bp ; Finish filling CFBBUF rep movsb ; More than enough bytes OPENFILE: ; Open the Data file mov ax,3D02 ; Read/Write mode Int 21 ; Open Data file xchg ax,bx ; Handle mov dh,databuf/100 REREAD: ; Loop here Until Read = 0 bytes mov si,filerrmsg jc Exit mov ch,readsize/100 mov ah,3F Int 21 jc reread GOODREAD: ; Check On Read length Or ax,ax ; 0 length Read = done jz endprog ; Any RET within ñ 80h push dx ; Databuf address mov si,dx push ax ; Bytes Read push bx ; Handle BLOCK: ; Process block of Data push ax ; # bytes Left In DATABUF push si ; Databuf pointer Call cipher ; Encrypt CFBBUF mov di,bp ; CFBbuf pop si ; Databuf pointer mov cl,blockbytes/2 DATACRYPT: ; Xor CFBBUF & Data mov ax,[si] ; Old Data value xchg [di],ax ; AX = CFB, [DI] = Data Xor [si],ax ; [SI] = newdata DIRECTION: movsw ; CMPSW For decrypt Loop datacrypt pop ax Sub ax,blockbytes ja block PTRSET: ; Decrement file pointer pop bx ; Handle pop dx ; Bytes Read push dx neg dx dec cx ; CX X=-(bytes Read) mov ax,4201 Int 21 ; Back file Ptr by bytes Read WRITEDATA: ; Write # bytes Read pop cx ; Bytes Read pop dx ; Databuf address mov ah,40 Int 21 jmp reread ; Start of subroutines XTIME: ; Subroutine For multiplication ; In GF(2^8) modulo x^8+x^4+x^3+x+1 shl al,1 jnc endprog Xor al,1B ENDPROG: ; Int 20 via PSP 00 ret KEYSCHED: ; Run key schedule On key ; RIJNDAEL key schedule expands first ; KEYBYTES of key into sufficient key ; material For ROUNDS+1 key mixing ; Rounds+2 avoids roundoff Error mov di,keyarray+keybytes ; Fall thru RJ mov dl,1 ; Initialize RCON mov cl,(rounds+2)*ncols/nkeys KEYSCHEDLOOP: push cx ; On entry CH = 0, saved mov bx,-4 ; Effective rotation of key cmp ch,3 ; material achieved by jnz $+4 ; index manipulation rcl bl,1 adc bl,0 ; BX = -3, -4, Or -7 mov al,[di+bx] test ch,-(ncols/8*10+4) jnz keycont ; TEST With 0EC Or 0FC KEYSUB: mov bx,sbox ; Bytesub xlat Or ch,ch jnz keycont Xor al,dl ; CH = 0, mix With RCON xchg ax,dx Call xtime ; Update RCON xchg ax,dx KEYCONT: ; Final Step For All keys Xor al,[di-keybytes] stosb inc ch cmp ch,keybytes jb keyschedloop+1 pop cx Loop keyschedloop CIPHER: ; The RIJNDAEL encryption cipher ; The 'state' of the cipher is located ; In CFBBUF And is treated As a Byte ; matrix of 4 rows by NCOLS columns ; For purpuses of SHIFTROW And ; MIXCOLUMN routines. BP is pointer ; To CFBBUF throughout, SI is pointer ; To Next Byte of key material. ; This routine automatically follows ; the KEYSCHED routine, Or is called ; directly From the BLOCK sequence. mov si,keyarray mov cx,rounds ; CH non-zero after Read push cx RIJNLOOP: ; Encrypt CFBBUF mov di,bp ; CFBBUF mov cl,blockbytes mov bx,sbox ADDKEYLOOP: lodsb ; Next key Byte Xor al,[di] xlat ; Do the BYTESUB here stosb Loop addkeyloop SHIFTROW: mov cl,3 ; CX is row # Base 0 std ; Move Right To Left SR_OUTER: mov bx,cx #If ncols EQ 8 cmp bx,2 jc $+3 inc bx ; 1,2,3 --> 1,3,4 #EndIf mov di,cfbbuf+blockbytes-4 Add di,cx ; Add row number SR_INNER: mov ch,ncols-1 push di mov al,[di] SHIFTER: ; Shift row 1 space <-- scasw scasw ; Move DI <-- 1 col xchg al,[di] dec ch jnz shifter pop di mov [di],al dec bx jnz sr_inner Loop sr_outer ENDSR: cld pop ax ; Round counter dec ax jz lastaddkey ; Skip last MIXCOLUMN push ax ; Restack Round counter MIXCOLUMN: ; Matrix mult In GF(2^8) mov di,bp ; CFBBUF mov cl,ncols NEXTCOL: ; Multiplier matrix is mov ch,4 ; º 2 3 1 1 º mov dx,[di] ; º 1 2 3 1 º mov bx,[di+2] ; º 1 1 2 3 º COLUMNLOOP: ; º 3 1 1 2 º mov ax,dx Call xtime ; 2x Byte 0 xchg ah,al Call xtime ; 2x Byte 1 Xor al,dh ; 3x Byte 1 Xor ax,bx ; Add In bytes 2 And 3 Xor al,ah ; AL=matrix product Byte stosb ; Store In original Byte xchg dh,dl ; Proceed To Next Byte xchg bl,dh ; 3 XCHGs equivalent To xchg bh,bl ; ROL 8 On 32-Bit reg dec ch jnz columnloop Loop nextcol jmp rijnloop LASTADDKEY: mov cl,blockbytes/2 mov di,bp LASTKEYLOOP: lodsw Xor [di],ax scasw Loop lastkeyloop ret USAGE db 'TINYRIJN ñ file',0 ASKFORKEY: db 'Key:',0,24 FILERRMSG: db 'File error',0 KEYBUF: db 2*keybytes+1 KEYARRAY equ $+1 ; Leave space For count FILESIZE equ $-100
Scott
mailto:[email protected][email protected]</A>
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