using System;
/*
* $Id: InfCodes.cs,v 1.2 2008/05/12 15:24:47 psoares33 Exp $
*
Copyright (c) 2000,2001,2002,2003 ymnk, JCraft,Inc. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the distribution.
3. The names of the authors may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This program is based on zlib-1.1.3, so all credit should go authors
* Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
* and contributors of zlib.
*/
namespace Org.BouncyCastle.Utilities.Zlib{
internal sealed class InfCodes{
private static readonly int[] inflate_mask = {
0x00000000, 0x00000001, 0x00000003, 0x00000007, 0x0000000f,
0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 0x000001ff,
0x000003ff, 0x000007ff, 0x00000fff, 0x00001fff, 0x00003fff,
0x00007fff, 0x0000ffff
};
private const int Z_OK=0;
private const int Z_STREAM_END=1;
private const int Z_NEED_DICT=2;
private const int Z_ERRNO=-1;
private const int Z_STREAM_ERROR=-2;
private const int Z_DATA_ERROR=-3;
private const int Z_MEM_ERROR=-4;
private const int Z_BUF_ERROR=-5;
private const int Z_VERSION_ERROR=-6;
// waiting for "i:"=input,
// "o:"=output,
// "x:"=nothing
private const int START=0; // x: set up for LEN
private const int LEN=1; // i: get length/literal/eob next
private const int LENEXT=2; // i: getting length extra (have base)
private const int DIST=3; // i: get distance next
private const int DISTEXT=4;// i: getting distance extra
private const int COPY=5; // o: copying bytes in window, waiting for space
private const int LIT=6; // o: got literal, waiting for output space
private const int WASH=7; // o: got eob, possibly still output waiting
private const int END=8; // x: got eob and all data flushed
private const int BADCODE=9;// x: got error
int mode; // current inflate_codes mode
// mode dependent information
int len;
int[] tree; // pointer into tree
int tree_index=0;
int need; // bits needed
int lit;
// if EXT or COPY, where and how much
int get; // bits to get for extra
int dist; // distance back to copy from
byte lbits; // ltree bits decoded per branch
byte dbits; // dtree bits decoder per branch
int[] ltree; // literal/length/eob tree
int ltree_index; // literal/length/eob tree
int[] dtree; // distance tree
int dtree_index; // distance tree
internal InfCodes(){
}
internal void init(int bl, int bd,
int[] tl, int tl_index,
int[] td, int td_index, ZStream z){
mode=START;
lbits=(byte)bl;
dbits=(byte)bd;
ltree=tl;
ltree_index=tl_index;
dtree = td;
dtree_index=td_index;
tree=null;
}
internal int proc(InfBlocks s, ZStream z, int r){
int j; // temporary storage
int tindex; // temporary pointer
int e; // extra bits or operation
int b=0; // bit buffer
int k=0; // bits in bit buffer
int p=0; // input data pointer
int n; // bytes available there
int q; // output window write pointer
int m; // bytes to end of window or read pointer
int f; // pointer to copy strings from
// copy input/output information to locals (UPDATE macro restores)
p=z.next_in_index;n=z.avail_in;b=s.bitb;k=s.bitk;
q=s.write;m=q<s.read?s.read-q-1:s.end-q;
// process input and output based on current state
while (true){
switch (mode){
// waiting for "i:"=input, "o:"=output, "x:"=nothing
case START: // x: set up for LEN
if (m >= 258 && n >= 10){
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
r = inflate_fast(lbits, dbits,
ltree, ltree_index,
dtree, dtree_index,
s, z);
p=z.next_in_index;n=z.avail_in;b=s.bitb;k=s.bitk;
q=s.write;m=q<s.read?s.read-q-1:s.end-q;
if (r != Z_OK){
mode = r == Z_STREAM_END ? WASH : BADCODE;
break;
}
}
need = lbits;
tree = ltree;
tree_index=ltree_index;
mode = LEN;
goto case LEN;
case LEN: // i: get length/literal/eob next
j = need;
while(k<(j)){
if(n!=0)r=Z_OK;
else{
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
}
n--;
b|=(z.next_in[p++]&0xff)<<k;
k+=8;
}
tindex=(tree_index+(b&inflate_mask[j]))*3;
b>>=(tree[tindex+1]);
k-=(tree[tindex+1]);
e=tree[tindex];
if(e == 0){ // literal
lit = tree[tindex+2];
mode = LIT;
break;
}
if((e & 16)!=0 ){ // length
get = e & 15;
len = tree[tindex+2];
mode = LENEXT;
break;
}
if ((e & 64) == 0){ // next table
need = e;
tree_index = tindex/3+tree[tindex+2];
break;
}
if ((e & 32)!=0){ // end of block
mode = WASH;
break;
}
mode = BADCODE; // invalid code
z.msg = "invalid literal/length code";
r = Z_DATA_ERROR;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
case LENEXT: // i: getting length extra (have base)
j = get;
while(k<(j)){
if(n!=0)r=Z_OK;
else{
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
}
n--; b|=(z.next_in[p++]&0xff)<<k;
k+=8;
}
len += (b & inflate_mask[j]);
b>>=j;
k-=j;
need = dbits;
tree = dtree;
tree_index=dtree_index;
mode = DIST;
goto case DIST;
case DIST: // i: get distance next
j = need;
while(k<(j)){
if(n!=0)r=Z_OK;
else{
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
}
n--; b|=(z.next_in[p++]&0xff)<<k;
k+=8;
}
tindex=(tree_index+(b & inflate_mask[j]))*3;
b>>=tree[tindex+1];
k-=tree[tindex+1];
e = (tree[tindex]);
if((e & 16)!=0){ // distance
get = e & 15;
dist = tree[tindex+2];
mode = DISTEXT;
break;
}
if ((e & 64) == 0){ // next table
need = e;
tree_index = tindex/3 + tree[tindex+2];
break;
}
mode = BADCODE; // invalid code
z.msg = "invalid distance code";
r = Z_DATA_ERROR;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
case DISTEXT: // i: getting distance extra
j = get;
while(k<(j)){
if(n!=0)r=Z_OK;
else{
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
}
n--; b|=(z.next_in[p++]&0xff)<<k;
k+=8;
}
dist += (b & inflate_mask[j]);
b>>=j;
k-=j;
mode = COPY;
goto case COPY;
case COPY: // o: copying bytes in window, waiting for space
f = q - dist;
while(f < 0){ // modulo window size-"while" instead
f += s.end; // of "if" handles invalid distances
}
while (len!=0){
if(m==0){
if(q==s.end&&s.read!=0){q=0;m=q<s.read?s.read-q-1:s.end-q;}
if(m==0){
s.write=q; r=s.inflate_flush(z,r);
q=s.write;m=q<s.read?s.read-q-1:s.end-q;
if(q==s.end&&s.read!=0){q=0;m=q<s.read?s.read-q-1:s.end-q;}
if(m==0){
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
}
}
}
s.window[q++]=s.window[f++]; m--;
if (f == s.end)
f = 0;
len--;
}
mode = START;
break;
case LIT: // o: got literal, waiting for output space
if(m==0){
if(q==s.end&&s.read!=0){q=0;m=q<s.read?s.read-q-1:s.end-q;}
if(m==0){
s.write=q; r=s.inflate_flush(z,r);
q=s.write;m=q<s.read?s.read-q-1:s.end-q;
if(q==s.end&&s.read!=0){q=0;m=q<s.read?s.read-q-1:s.end-q;}
if(m==0){
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
}
}
}
r=Z_OK;
s.window[q++]=(byte)lit; m--;
mode = START;
break;
case WASH: // o: got eob, possibly more output
if (k > 7){ // return unused byte, if any
k -= 8;
n++;
p--; // can always return one
}
s.write=q; r=s.inflate_flush(z,r);
q=s.write;m=q<s.read?s.read-q-1:s.end-q;
if (s.read != s.write){
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
}
mode = END;
goto case END;
case END:
r = Z_STREAM_END;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
case BADCODE: // x: got error
r = Z_DATA_ERROR;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
default:
r = Z_STREAM_ERROR;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return s.inflate_flush(z,r);
}
}
}
internal void free(ZStream z){
// ZFREE(z, c);
}
// Called with number of bytes left to write in window at least 258
// (the maximum string length) and number of input bytes available
// at least ten. The ten bytes are six bytes for the longest length/
// distance pair plus four bytes for overloading the bit buffer.
internal int inflate_fast(int bl, int bd,
int[] tl, int tl_index,
int[] td, int td_index,
InfBlocks s, ZStream z){
int t; // temporary pointer
int[] tp; // temporary pointer
int tp_index; // temporary pointer
int e; // extra bits or operation
int b; // bit buffer
int k; // bits in bit buffer
int p; // input data pointer
int n; // bytes available there
int q; // output window write pointer
int m; // bytes to end of window or read pointer
int ml; // mask for literal/length tree
int md; // mask for distance tree
int c; // bytes to copy
int d; // distance back to copy from
int r; // copy source pointer
int tp_index_t_3; // (tp_index+t)*3
// load input, output, bit values
p=z.next_in_index;n=z.avail_in;b=s.bitb;k=s.bitk;
q=s.write;m=q<s.read?s.read-q-1:s.end-q;
// initialize masks
ml = inflate_mask[bl];
md = inflate_mask[bd];
// do until not enough input or output space for fast loop
do { // assume called with m >= 258 && n >= 10
// get literal/length code
while(k<(20)){ // max bits for literal/length code
n--;
b|=(z.next_in[p++]&0xff)<<k;k+=8;
}
t= b&ml;
tp=tl;
tp_index=tl_index;
tp_index_t_3=(tp_index+t)*3;
if ((e = tp[tp_index_t_3]) == 0){
b>>=(tp[tp_index_t_3+1]); k-=(tp[tp_index_t_3+1]);
s.window[q++] = (byte)tp[tp_index_t_3+2];
m--;
continue;
}
do {
b>>=(tp[tp_index_t_3+1]); k-=(tp[tp_index_t_3+1]);
if((e&16)!=0){
e &= 15;
c = tp[tp_index_t_3+2] + ((int)b & inflate_mask[e]);
b>>=e; k-=e;
// decode distance base of block to copy
while(k<(15)){ // max bits for distance code
n--;
b|=(z.next_in[p++]&0xff)<<k;k+=8;
}
t= b&md;
tp=td;
tp_index=td_index;
tp_index_t_3=(tp_index+t)*3;
e = tp[tp_index_t_3];
do {
b>>=(tp[tp_index_t_3+1]); k-=(tp[tp_index_t_3+1]);
if((e&16)!=0){
// get extra bits to add to distance base
e &= 15;
while(k<(e)){ // get extra bits (up to 13)
n--;
b|=(z.next_in[p++]&0xff)<<k;k+=8;
}
d = tp[tp_index_t_3+2] + (b&inflate_mask[e]);
b>>=(e); k-=(e);
// do the copy
m -= c;
if (q >= d){ // offset before dest
// just copy
r=q-d;
if(q-r>0 && 2>(q-r)){
s.window[q++]=s.window[r++]; // minimum count is three,
s.window[q++]=s.window[r++]; // so unroll loop a little
c-=2;
}
else{
System.Array.Copy(s.window, r, s.window, q, 2);
q+=2; r+=2; c-=2;
}
}
else{ // else offset after destination
r=q-d;
do{
r+=s.end; // force pointer in window
}while(r<0); // covers invalid distances
e=s.end-r;
if(c>e){ // if source crosses,
c-=e; // wrapped copy
if(q-r>0 && e>(q-r)){
do{s.window[q++] = s.window[r++];}
while(--e!=0);
}
else{
System.Array.Copy(s.window, r, s.window, q, e);
q+=e; r+=e; e=0;
}
r = 0; // copy rest from start of window
}
}
// copy all or what's left
if(q-r>0 && c>(q-r)){
do{s.window[q++] = s.window[r++];}
while(--c!=0);
}
else{
System.Array.Copy(s.window, r, s.window, q, c);
q+=c; r+=c; c=0;
}
break;
}
else if((e&64)==0){
t+=tp[tp_index_t_3+2];
t+=(b&inflate_mask[e]);
tp_index_t_3=(tp_index+t)*3;
e=tp[tp_index_t_3];
}
else{
z.msg = "invalid distance code";
c=z.avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return Z_DATA_ERROR;
}
}
while(true);
break;
}
if((e&64)==0){
t+=tp[tp_index_t_3+2];
t+=(b&inflate_mask[e]);
tp_index_t_3=(tp_index+t)*3;
if((e=tp[tp_index_t_3])==0){
b>>=(tp[tp_index_t_3+1]); k-=(tp[tp_index_t_3+1]);
s.window[q++]=(byte)tp[tp_index_t_3+2];
m--;
break;
}
}
else if((e&32)!=0){
c=z.avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return Z_STREAM_END;
}
else{
z.msg="invalid literal/length code";
c=z.avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return Z_DATA_ERROR;
}
}
while(true);
}
while(m>=258 && n>= 10);
// not enough input or output--restore pointers and return
c=z.avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;
s.bitb=b;s.bitk=k;
z.avail_in=n;z.total_in+=p-z.next_in_index;z.next_in_index=p;
s.write=q;
return Z_OK;
}
}
}
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