;One crypto-cycle (Cycle j1):
;In:	i = temp (cycle number)
;	L = @_N1
;	R = @_N2
;Out:	RES = @RES

Crypto:	ldx	MKey
	clr	tempH
	lsl	temp		;temp * 2
	lsl	temp		;temp * 2
	add	XL,temp
	adc	XH,tempH	;X - pointer to MKey

;res = _n1 + MKey[i]

	ldy	Res
	ldz	_n1
	ld	temp,Z+
	ld	tempL,X+
	add	temp,tempL
	st	Y+,temp
	ld	temp,Z+
	ld	tempL,X+
	adc	temp,tempL
	st	Y+,temp
	ld	temp,Z+
	ld	tempL,X+
	adc	temp,tempL
	st	Y+,temp
	ld	temp,Z+
	ld	tempL,X+
	adc	temp,tempL
	st	Y+,temp
	
;for(Cnt = 0; Cnt < 8; Cnt++)

	ldy	Res
	ldi	Cnt,0
	
;temp = res >> (4 * Cnt) & 0x0F
	
XLat:	ld	temp,Y
	sbrc	Cnt,0
	swap	temp
	mov	XL,temp
	andi	temp,0x0F

;temp = RTable[Cnt][temp]

	table	RTable
	mov	tempL,Cnt
	lsl	tempL		;tempL * 2
	lsl	tempL		;tempL * 2
	lsl	tempL		;tempL * 2
	lsl	tempL		;tempL * 2
	add	temp,tempL	;C = 0
	mov	tempL,temp
	ror	temp
	add	ZL,temp
	adc	ZH,tempH
	lpm	temp,Z
	sbrc	tempL,0
	swap	temp
	andi	temp,0x0F

;res = res & (0x0F << (4 * Cnt)) | (temp << (4 * Cnt))

	andi	XL,0xF0
	or	temp,XL
	sbrc	Cnt,0
	swap	temp
	st	Y,temp
	sbrc	Cnt,0
	adiw	YH:YL,1

	inc	Cnt
	cpi	Cnt,8
	brne	XLat

;r7:r6:r5:r4 = res rol 8

	ldy	Res
	ld	r5,Y+
	ld	r6,Y+
	ld	r7,Y+
	ld	r4,Y+

;r7:r6:r5:r4 = r7:r6:r5:r4 rol 3

	ldi	Cnt,3
rol3:	mov	temp,r7
	rol	temp
	rol	r4
	rol	r5
	rol	r6
	rol	r7
	dec	Cnt
	brne	rol3

;res = r7:r6:r5:r4 ^ _n2

	ldx	_n2
	ldy	Res
	ld	temp,X+
	eor	temp,r4
	st	Y+,temp
	ld	temp,X+
	eor	temp,r5
	st	Y+,temp
	ld	temp,X+
	eor	temp,r6
	st	Y+,temp
	ld	temp,X+
	eor	temp,r7
	st	Y+,temp

	ret

;32 crypto cycles (Cycle 32-encryption):
;In:	@_N1
;	@_N2
;Out:	@_N1
;	@_N2

Crypt32:
	clr	Cnt1
Iter1:	mov	temp,Cnt1
	rcall	Crypto
	ldx	_n2
	ldy	_n1
	rcall	Mov32
	ldx	_n1
	ldy	Res
	rcall	Mov32
	inc	Cnt1
	cpi	Cnt1,8
	brne	iter1

	clr	Cnt1
Iter2:	mov	temp,Cnt1
	rcall	Crypto
	ldx	_n2
	ldy	_n1
	rcall	Mov32
	ldx	_n1
	ldy	Res
	rcall	Mov32
	inc	Cnt1
	cpi	Cnt1,8
	brne	iter2

	clr	Cnt1
Iter3:	mov	temp,Cnt1
	rcall	Crypto
	ldx	_n2
	ldy	_n1
	rcall	Mov32
	ldx	_n1
	ldy	Res
	rcall	Mov32
	inc	Cnt1
	cpi	Cnt1,8
	brne	iter3

	ldi	Cnt1,7
Iter4:	mov	temp,Cnt1
	rcall	Crypto
	ldx	_n2
	ldy	_n1
	rcall	Mov32
	ldx	_n1
	ldy	Res
	rcall	Mov32
	dec	Cnt1
	brne	iter4

	clr	temp
	rcall	Crypto
	ldx	_n2
	ldy	Res
	rcall	Mov32
	ret

;Moves 32-bit value
;@X = @Y
;In:	XH:XL - destination
;	YH:YL - source
	
Mov32:	ldi	Cnt,4
Mv:	ld	temp,Y+
	st	X+,temp
	dec	Cnt
	brne	Mv
	ret