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|
;;
;; tinfzlib - tiny zlib uncompress
;;
;; Copyright (c) 2003 by Joergen Ibsen / Jibz
;; All Rights Reserved
;;
;; http://www.ibsensoftware.com/
;;
;; This software is provided 'as-is', without any express
;; or implied warranty. In no event will the authors be
;; held liable for any damages arising from the use of
;; this software.
;;
;; Permission is granted to anyone to use this software
;; for any purpose, including commercial applications,
;; and to alter it and redistribute it freely, subject to
;; the following restrictions:
;;
;; 1. The origin of this software must not be
;; misrepresented; you must not claim that you
;; wrote the original software. If you use this
;; software in a product, an acknowledgment in
;; the product documentation would be appreciated
;; but is not required.
;;
;; 2. Altered source versions must be plainly marked
;; as such, and must not be misrepresented as
;; being the original software.
;;
;; 3. This notice may not be removed or altered from
;; any source distribution.
;;
TINF_OK equ 0
TINF_DATA_ERROR equ (-3)
cpu 386
bits 32
%include "nasmlcm.inc"
section lcmtext
lcmglobal tinf_zlib_uncompress,16
lcmexport tinf_zlib_uncompress,16
lcmextern tinf_uncompress,16
lcmextern tinf_adler32,8
; =============================================================
lcmlabel tinf_zlib_uncompress,16
; tinf_zlib_uncompress(void *dest,
; unsigned int *destLen,
; const void *source,
; unsigned int sourceLen)
.slen$ equ 2*4 + 4 + 12
.src$ equ 2*4 + 4 + 8
.dlen$ equ 2*4 + 4 + 4
.dst$ equ 2*4 + 4
push esi
push ebx
mov esi, [esp + .src$] ; esi -> source
; -- get header bytes --
movzx eax, word [esi] ; al = cmf, ah = flg,
; -- check format --
; check method is deflate
; if ((cmf & 0x0f) != 8) return TINF_DATA_ERROR;
mov cl, 0x0f
and cl, al
cmp cl, 8
jne short .return_error
; check window size is valid
; if ((cmf >> 4) > 7) return TINF_DATA_ERROR;
mov ch, al
shr ch, 4
cmp ch, cl ; cl = 8 from above
jae short .return_error
; check there is no preset dictionary
; if (flg & 0x20) return TINF_DATA_ERROR;
test ah, 0x20
jnz short .return_error
; check checksum
; if ((256*cmf + flg) % 31) return TINF_DATA_ERROR;
xchg al, ah
xor edx, edx
lea ebx, [edx + 31]
div ebx
test edx, edx
jnz short .return_error
; -- get adler32 checksum --
mov ecx, [esp + .slen$] ; ecx = sourceLen
mov ebx, [esi + ecx - 4]
%ifdef BSWAP_OK
bswap ebx
%else ; BSWAP_OK
xchg bl, bh
rol ebx, 16
xchg bl, bh
%endif ; BSWAP_OK
; -- inflate --
; res = tinf_uncompress(dst, destLen, src + 2, sourceLen - 6);
lea eax, [ecx - 6]
push eax
lea eax, [esi + 2]
push eax
push dword [esp + 8 + .dlen$]
push dword [esp + 12 + .dst$]
call tinf_uncompress
add esp, byte 16
; if (res != TINF_OK) return TINF_DATA_ERROR;
test eax, eax
jnz short .return_error
; -- check adler32 checksum --
; if (a32 != tinf_adler32(dst, *destLen)) return TINF_DATA_ERROR;
mov eax, [esp + .dlen$];
push dword [eax]
push dword [esp + 4 + .dst$]
call tinf_adler32
add esp, byte 8
sub eax, ebx
jz short .return_eax
.return_error:
mov eax, TINF_DATA_ERROR
.return_eax:
pop ebx
pop esi
lcmret 16
; =============================================================
%ifdef _OBJ_
section lcmdata
%endif
; =============================================================
|
