using System; /* * $Id: InfCodes.cs,v 1.2 2008-05-10 09:35:40 bouncy 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= 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>=(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)<>=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)<>=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)<>=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 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= 258 && n >= 10 // get literal/length code while(k<(20)){ // max bits for literal/length code n--; b|=(z.next_in[p++]&0xff)<>=(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)<>=(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)<>=(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)>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)>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)>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)>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; } } }