c-win32.asm

老外写的加密库cryptlib(版本3.1)

	; Don't even think of reading this code
	; It was automatically generated by cast-586.pl
	; Which is a perl program used to generate the x86 assember for
	; any of elf, a.out, BSDI, Win32, gaswin (for GNU as on Win32) or Solaris
	; eric <[e-mail]>
	; 
segment .text
extern	_CAST_S_table0
extern	_CAST_S_table1
extern	_CAST_S_table2
extern	_CAST_S_table3
global	_CAST_encrypt
_CAST_encrypt:
	; 
	push	ebp
	push	ebx
	mov	ebx,		[12+esp]
	mov	ebp,		[16+esp]
	push	esi
	push	edi
	; Load the 2 words
	mov	edi,		[ebx]
	mov	esi,		[4+ebx]
	; Get short key flag
	mov	eax,		[128+ebp]
	push	eax
	xor	eax,		eax
	; round 0
	mov	edx,		[ebp]
	mov	ecx,		[4+ebp]
	add	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	add	ecx,		ebx
	xor	edi,		ecx
	; round 1
	mov	edx,		[8+ebp]
	mov	ecx,		[12+ebp]
	xor	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	xor	ecx,		ebx
	xor	esi,		ecx
	; round 2
	mov	edx,		[16+ebp]
	mov	ecx,		[20+ebp]
	sub	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	sub	ecx,		ebx
	xor	edi,		ecx
	; round 3
	mov	edx,		[24+ebp]
	mov	ecx,		[28+ebp]
	add	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	add	ecx,		ebx
	xor	esi,		ecx
	; round 4
	mov	edx,		[32+ebp]
	mov	ecx,		[36+ebp]
	xor	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	xor	ecx,		ebx
	xor	edi,		ecx
	; round 5
	mov	edx,		[40+ebp]
	mov	ecx,		[44+ebp]
	sub	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	sub	ecx,		ebx
	xor	esi,		ecx
	; round 6
	mov	edx,		[48+ebp]
	mov	ecx,		[52+ebp]
	add	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	add	ecx,		ebx
	xor	edi,		ecx
	; round 7
	mov	edx,		[56+ebp]
	mov	ecx,		[60+ebp]
	xor	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	xor	ecx,		ebx
	xor	esi,		ecx
	; round 8
	mov	edx,		[64+ebp]
	mov	ecx,		[68+ebp]
	sub	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	sub	ecx,		ebx
	xor	edi,		ecx
	; round 9
	mov	edx,		[72+ebp]
	mov	ecx,		[76+ebp]
	add	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	add	ecx,		ebx
	xor	esi,		ecx
	; round 10
	mov	edx,		[80+ebp]
	mov	ecx,		[84+ebp]
	xor	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	xor	ecx,		ebx
	xor	edi,		ecx
	; round 11
	mov	edx,		[88+ebp]
	mov	ecx,		[92+ebp]
	sub	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	sub	ecx,		ebx
	xor	esi,		ecx
	; test short key flag
	pop	edx
	or	edx,		edx
	jnz NEAR	$L000cast_enc_done
	; round 12
	mov	edx,		[96+ebp]
	mov	ecx,		[100+ebp]
	add	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	add	ecx,		ebx
	xor	edi,		ecx
	; round 13
	mov	edx,		[104+ebp]
	mov	ecx,		[108+ebp]
	xor	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	xor	ecx,		ebx
	xor	esi,		ecx
	; round 14
	mov	edx,		[112+ebp]
	mov	ecx,		[116+ebp]
	sub	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	sub	ecx,		ebx
	xor	edi,		ecx
	; round 15
	mov	edx,		[120+ebp]
	mov	ecx,		[124+ebp]
	add	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	add	ecx,		ebx
	xor	esi,		ecx
$L000cast_enc_done:
	nop
	mov	eax,		[20+esp]
	mov	[4+eax],	edi
	mov	[eax],		esi
	pop	edi
	pop	esi
	pop	ebx
	pop	ebp
	ret
extern	_CAST_S_table0
extern	_CAST_S_table1
extern	_CAST_S_table2
extern	_CAST_S_table3
global	_CAST_decrypt
_CAST_decrypt:
	; 
	push	ebp
	push	ebx
	mov	ebx,		[12+esp]
	mov	ebp,		[16+esp]
	push	esi
	push	edi
	; Load the 2 words
	mov	edi,		[ebx]
	mov	esi,		[4+ebx]
	; Get short key flag
	mov	eax,		[128+ebp]
	or	eax,		eax
	jnz NEAR	$L001cast_dec_skip
	xor	eax,		eax
	; round 15
	mov	edx,		[120+ebp]
	mov	ecx,		[124+ebp]
	add	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	add	ecx,		ebx
	xor	edi,		ecx
	; round 14
	mov	edx,		[112+ebp]
	mov	ecx,		[116+ebp]
	sub	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	xor	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	sub	ecx,		ebx
	xor	esi,		ecx
	; round 13
	mov	edx,		[104+ebp]
	mov	ecx,		[108+ebp]
	xor	edx,		esi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255
	shr	edx,		16
	xor	eax,		eax
	mov	al,		dh
	and	edx,		255
	mov	ecx,		[_CAST_S_table0+ecx*4]
	mov	ebx,		[_CAST_S_table1+ebx*4]
	sub	ecx,		ebx
	mov	ebx,		[_CAST_S_table2+eax*4]
	add	ecx,		ebx
	mov	ebx,		[_CAST_S_table3+edx*4]
	xor	ecx,		ebx
	xor	edi,		ecx
	; round 12
	mov	edx,		[96+ebp]
	mov	ecx,		[100+ebp]
	add	edx,		edi
	rol	edx,		cl
	mov	ebx,		edx
	xor	ecx,		ecx
	mov	cl,		dh
	and	ebx,		255