diff options
Diffstat (limited to 'src/Boot/Windows/Decompressor.c')
| -rw-r--r-- | src/Boot/Windows/Decompressor.c | 853 |
1 files changed, 444 insertions, 409 deletions
diff --git a/src/Boot/Windows/Decompressor.c b/src/Boot/Windows/Decompressor.c index efdbed91..a84f2efd 100644 --- a/src/Boot/Windows/Decompressor.c +++ b/src/Boot/Windows/Decompressor.c @@ -1,410 +1,432 @@ -/*
- puff.c
- Copyright (C) 2002-2004 Mark Adler, all rights reserved
- version 1.8, 9 Jan 2004
-
- This software is provided 'as-is', without any express or implied
- warranty. In no event will the author 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.
-
- Mark Adler madler@alumni.caltech.edu
-*/
-
-/* Adapted for TrueCrypt */
-
-
-#define local static /* for local function definitions */
-#define NIL ((unsigned char *)0) /* for no output option */
-
-/*
- * Maximums for allocations and loops. It is not useful to change these --
- * they are fixed by the deflate format.
- */
-#define MAXBITS 15 /* maximum bits in a code */
-#define MAXLCODES 286 /* maximum number of literal/length codes */
-#define MAXDCODES 30 /* maximum number of distance codes */
-#define MAXCODES (MAXLCODES+MAXDCODES) /* maximum codes lengths to read */
-#define FIXLCODES 288 /* number of fixed literal/length codes */
-
-/* input and output state */
-struct state {
- /* output state */
- unsigned char *out; /* output buffer */
- unsigned int outlen; /* available space at out */
- unsigned int outcnt; /* bytes written to out so far */
-
- /* input state */
- unsigned char *in; /* input buffer */
- unsigned int incnt; /* bytes read so far */
- int bitbuf; /* bit buffer */
- int bitcnt; /* number of bits in bit buffer */
-};
-
-
-local int bits(struct state *s, int need)
-{
- long val; /* bit accumulator (can use up to 20 bits) */
-
- /* load at least need bits into val */
- val = s->bitbuf;
- while (s->bitcnt < need) {
- val |= (long)(s->in[s->incnt++]) << s->bitcnt; /* load eight bits */
- s->bitcnt += 8;
- }
-
- /* drop need bits and update buffer, always zero to seven bits left */
- s->bitbuf = (int)(val >> need);
- s->bitcnt -= need;
-
- /* return need bits, zeroing the bits above that */
- return (int)(val & ((1L << need) - 1));
-}
-
-
-local int stored(struct state *s)
-{
- unsigned len; /* length of stored block */
-
- /* discard leftover bits from current byte (assumes s->bitcnt < 8) */
- s->bitbuf = 0;
- s->bitcnt = 0;
-
- /* get length and check against its one's complement */
- len = s->in[s->incnt++];
- len |= s->in[s->incnt++] << 8;
- if (s->in[s->incnt++] != (~len & 0xff) ||
- s->in[s->incnt++] != ((~len >> 8) & 0xff))
- return -2; /* didn't match complement! */
-
- /* copy len bytes from in to out */
- if (s->out != NIL) {
- if (s->outcnt + len > s->outlen)
- return 1; /* not enough output space */
- while (len--)
- s->out[s->outcnt++] = s->in[s->incnt++];
- }
- else { /* just scanning */
- s->outcnt += len;
- s->incnt += len;
- }
-
- /* done with a valid stored block */
- return 0;
-}
-
-
-struct huffman {
- short *count; /* number of symbols of each length */
- short *symbol; /* canonically ordered symbols */
-};
-
-
-#ifdef SLOW
-local int decode(struct state *s, struct huffman *h)
-{
- int len; /* current number of bits in code */
- int code; /* len bits being decoded */
- int first; /* first code of length len */
- int count; /* number of codes of length len */
- int index; /* index of first code of length len in symbol table */
-
- code = first = index = 0;
- for (len = 1; len <= MAXBITS; len++) {
- code |= bits(s, 1); /* get next bit */
- count = h->count[len];
- if (code < first + count) /* if length len, return symbol */
- return h->symbol[index + (code - first)];
- index += count; /* else update for next length */
- first += count;
- first <<= 1;
- code <<= 1;
- }
- return -9; /* ran out of codes */
-}
-
-/*
- * A faster version of decode() for real applications of this code. It's not
- * as readable, but it makes puff() twice as fast. And it only makes the code
- * a few percent larger.
- */
-#else /* !SLOW */
-local int decode(struct state *s, struct huffman *h)
-{
- int len; /* current number of bits in code */
- int code; /* len bits being decoded */
- int first; /* first code of length len */
- int count; /* number of codes of length len */
- int index; /* index of first code of length len in symbol table */
- int bitbuf; /* bits from stream */
- int left; /* bits left in next or left to process */
- short *next; /* next number of codes */
-
- bitbuf = s->bitbuf;
- left = s->bitcnt;
- code = first = index = 0;
- len = 1;
- next = h->count + 1;
- while (1) {
- while (left--) {
- code |= bitbuf & 1;
- bitbuf >>= 1;
- count = *next++;
- if (code < first + count) { /* if length len, return symbol */
- s->bitbuf = bitbuf;
- s->bitcnt = (s->bitcnt - len) & 7;
- return h->symbol[index + (code - first)];
- }
- index += count; /* else update for next length */
- first += count;
- first <<= 1;
- code <<= 1;
- len++;
- }
- left = (MAXBITS+1) - len;
- if (left == 0) break;
- bitbuf = s->in[s->incnt++];
- if (left > 8) left = 8;
- }
- return -9; /* ran out of codes */
-}
-#endif /* SLOW */
-
-
-local int construct(struct huffman *h, short *length, int n)
-{
- int symbol; /* current symbol when stepping through length[] */
- int len; /* current length when stepping through h->count[] */
- int left; /* number of possible codes left of current length */
- short offs[MAXBITS+1]; /* offsets in symbol table for each length */
-
- /* count number of codes of each length */
- for (len = 0; len <= MAXBITS; len++)
- h->count[len] = 0;
- for (symbol = 0; symbol < n; symbol++)
- (h->count[length[symbol]])++; /* assumes lengths are within bounds */
- if (h->count[0] == n) /* no codes! */
- return 0; /* complete, but decode() will fail */
-
- /* check for an over-subscribed or incomplete set of lengths */
- left = 1; /* one possible code of zero length */
- for (len = 1; len <= MAXBITS; len++) {
- left <<= 1; /* one more bit, double codes left */
- left -= h->count[len]; /* deduct count from possible codes */
- if (left < 0) return left; /* over-subscribed--return negative */
- } /* left > 0 means incomplete */
-
- /* generate offsets into symbol table for each length for sorting */
- offs[1] = 0;
- for (len = 1; len < MAXBITS; len++)
- offs[len + 1] = offs[len] + h->count[len];
-
- /*
- * put symbols in table sorted by length, by symbol order within each
- * length
- */
- for (symbol = 0; symbol < n; symbol++)
- if (length[symbol] != 0)
- h->symbol[offs[length[symbol]]++] = symbol;
-
- /* return zero for complete set, positive for incomplete set */
- return left;
-}
-
-
-local int codes(struct state *s,
- struct huffman *lencode,
- struct huffman *distcode)
-{
- int symbol; /* decoded symbol */
- int len; /* length for copy */
- unsigned dist; /* distance for copy */
- static const short lens[29] = { /* Size base for length codes 257..285 */
- 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
- 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258};
- static const short lext[29] = { /* Extra bits for length codes 257..285 */
- 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
- 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0};
- static const short dists[30] = { /* Offset base for distance codes 0..29 */
- 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
- 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
- 8193, 12289, 16385, 24577};
- static const short dext[30] = { /* Extra bits for distance codes 0..29 */
- 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
- 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
- 12, 12, 13, 13};
-
- /* decode literals and length/distance pairs */
- do {
- symbol = decode(s, lencode);
- if (symbol < 0) return symbol; /* invalid symbol */
- if (symbol < 256) { /* literal: symbol is the byte */
- /* write out the literal */
- if (s->out != NIL) {
- if (s->outcnt == s->outlen) return 1;
- s->out[s->outcnt] = symbol;
- }
- s->outcnt++;
- }
- else if (symbol > 256) { /* length */
- /* get and compute length */
- symbol -= 257;
- if (symbol >= 29) return -9; /* invalid fixed code */
- len = lens[symbol] + bits(s, lext[symbol]);
-
- /* get and check distance */
- symbol = decode(s, distcode);
- if (symbol < 0) return symbol; /* invalid symbol */
- dist = dists[symbol] + bits(s, dext[symbol]);
- if (dist > s->outcnt)
- return -10; /* distance too far back */
-
- /* copy length bytes from distance bytes back */
- if (s->out != NIL) {
- if (s->outcnt + len > s->outlen) return 1;
- while (len--) {
- s->out[s->outcnt] = s->out[s->outcnt - dist];
- s->outcnt++;
- }
- }
- else
- s->outcnt += len;
- }
- } while (symbol != 256); /* end of block symbol */
-
- /* done with a valid fixed or dynamic block */
- return 0;
-}
-
-
-local int fixed(struct state *s)
-{
- static int virgin = 1;
- static short lencnt[MAXBITS+1], lensym[FIXLCODES];
- static short distcnt[MAXBITS+1], distsym[MAXDCODES];
- static struct huffman lencode = {lencnt, lensym};
- static struct huffman distcode = {distcnt, distsym};
-
- /* build fixed huffman tables if first call (may not be thread safe) */
- if (virgin) {
- int symbol;
- short lengths[FIXLCODES];
-
- /* literal/length table */
- for (symbol = 0; symbol < 144; symbol++)
- lengths[symbol] = 8;
- for (; symbol < 256; symbol++)
- lengths[symbol] = 9;
- for (; symbol < 280; symbol++)
- lengths[symbol] = 7;
- for (; symbol < FIXLCODES; symbol++)
- lengths[symbol] = 8;
- construct(&lencode, lengths, FIXLCODES);
-
- /* distance table */
- for (symbol = 0; symbol < MAXDCODES; symbol++)
- lengths[symbol] = 5;
- construct(&distcode, lengths, MAXDCODES);
-
- /* do this just once */
- virgin = 0;
- }
-
- /* decode data until end-of-block code */
- return codes(s, &lencode, &distcode);
-}
-
-
-local int dynamic(struct state *s)
-{
- int nlen, ndist, ncode; /* number of lengths in descriptor */
- int index; /* index of lengths[] */
- int err; /* construct() return value */
- short lengths[MAXCODES]; /* descriptor code lengths */
- short lencnt[MAXBITS+1], lensym[MAXLCODES]; /* lencode memory */
- short distcnt[MAXBITS+1], distsym[MAXDCODES]; /* distcode memory */
- struct huffman lencode = {lencnt, lensym}; /* length code */
- struct huffman distcode = {distcnt, distsym}; /* distance code */
- static const short order[19] = /* permutation of code length codes */
- {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
-
- /* get number of lengths in each table, check lengths */
- nlen = bits(s, 5) + 257;
- ndist = bits(s, 5) + 1;
- ncode = bits(s, 4) + 4;
- if (nlen > MAXLCODES || ndist > MAXDCODES)
- return -3; /* bad counts */
-
- /* read code length code lengths (really), missing lengths are zero */
- for (index = 0; index < ncode; index++)
- lengths[order[index]] = bits(s, 3);
- for (; index < 19; index++)
- lengths[order[index]] = 0;
-
- /* build huffman table for code lengths codes (use lencode temporarily) */
- err = construct(&lencode, lengths, 19);
- if (err != 0) return -4; /* require complete code set here */
-
- /* read length/literal and distance code length tables */
- index = 0;
- while (index < nlen + ndist) {
- int symbol; /* decoded value */
- int len; /* last length to repeat */
-
- symbol = decode(s, &lencode);
- if (symbol < 16) /* length in 0..15 */
- lengths[index++] = symbol;
- else { /* repeat instruction */
- len = 0; /* assume repeating zeros */
- if (symbol == 16) { /* repeat last length 3..6 times */
- if (index == 0) return -5; /* no last length! */
- len = lengths[index - 1]; /* last length */
- symbol = 3 + bits(s, 2);
- }
- else if (symbol == 17) /* repeat zero 3..10 times */
- symbol = 3 + bits(s, 3);
- else /* == 18, repeat zero 11..138 times */
- symbol = 11 + bits(s, 7);
- if (index + symbol > nlen + ndist)
- return -6; /* too many lengths! */
- while (symbol--) /* repeat last or zero symbol times */
- lengths[index++] = len;
- }
- }
-
- /* build huffman table for literal/length codes */
- err = construct(&lencode, lengths, nlen);
- if (err < 0 || (err > 0 && nlen - lencode.count[0] != 1))
- return -7; /* only allow incomplete codes if just one code */
-
- /* build huffman table for distance codes */
- err = construct(&distcode, lengths + nlen, ndist);
- if (err < 0 || (err > 0 && ndist - distcode.count[0] != 1))
- return -8; /* only allow incomplete codes if just one code */
-
- /* decode data until end-of-block code */
- return codes(s, &lencode, &distcode);
-}
-
-
-void _acrtused () { }
-
-// Decompress deflated data
+/* + puff.c + Copyright (C) 2002-2004 Mark Adler, all rights reserved + version 1.8, 9 Jan 2004 + + This software is provided 'as-is', without any express or implied + warranty. In no event will the author 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. + + Mark Adler madler@alumni.caltech.edu +*/ + +/* Adapted for TrueCrypt */ + + +#define local static /* for local function definitions */ +#define NIL ((unsigned char *)0) /* for no output option */ + +/* + * Maximums for allocations and loops. It is not useful to change these -- + * they are fixed by the deflate format. + */ +#define MAXBITS 15 /* maximum bits in a code */ +#define MAXLCODES 286 /* maximum number of literal/length codes */ +#define MAXDCODES 30 /* maximum number of distance codes */ +#define MAXCODES (MAXLCODES+MAXDCODES) /* maximum codes lengths to read */ +#define FIXLCODES 288 /* number of fixed literal/length codes */ + +/* input and output state */ +struct state { + /* output state */ + unsigned char *out; /* output buffer */ + unsigned int outlen; /* available space at out */ + unsigned int outcnt; /* bytes written to out so far */ + + /* input state */ + unsigned char *in; /* input buffer */ + unsigned int inlen; /* available input at in */ + unsigned int incnt; /* bytes read so far */ + int bitbuf; /* bit buffer */ + int bitcnt; /* number of bits in bit buffer */ +}; + + +local int bits(struct state *s, int need) +{ + long val; /* bit accumulator (can use up to 20 bits) */ + + /* load at least need bits into val */ + val = s->bitbuf; + while (s->bitcnt < need) { + val |= (long)(s->in[s->incnt++]) << s->bitcnt; /* load eight bits */ + s->bitcnt += 8; + } + + /* drop need bits and update buffer, always zero to seven bits left */ + s->bitbuf = (int)(val >> need); + s->bitcnt -= need; + + /* return need bits, zeroing the bits above that */ + return (int)(val & ((1L << need) - 1)); +} + + +local int stored(struct state *s) +{ + unsigned len; /* length of stored block */ + + /* discard leftover bits from current byte (assumes s->bitcnt < 8) */ + s->bitbuf = 0; + s->bitcnt = 0; + + if (s->incnt + 4 > s->inlen)
+ return 2; /* not enough input */ + + /* get length and check against its one's complement */ + len = s->in[s->incnt++]; + len |= s->in[s->incnt++] << 8; + if (s->in[s->incnt++] != (~len & 0xff) || + s->in[s->incnt++] != ((~len >> 8) & 0xff)) + return -2; /* didn't match complement! */ + + if (s->incnt + len > s->inlen)
+ return 2; /* not enough input */ + + /* copy len bytes from in to out */ + if (s->out != NIL) { + if (s->outcnt + len > s->outlen) + return 1; /* not enough output space */ + while (len--) + s->out[s->outcnt++] = s->in[s->incnt++]; + } + else { /* just scanning */ + s->outcnt += len; + s->incnt += len; + } + + /* done with a valid stored block */ + return 0; +} + + +struct huffman { + short *count; /* number of symbols of each length */ + short *symbol; /* canonically ordered symbols */ +}; + +/* reduce code size by using slow version of the decompressor */ +#define SLOW + +#ifdef SLOW +local int decode(struct state *s, struct huffman *h) +{ + int len; /* current number of bits in code */ + int code; /* len bits being decoded */ + int first; /* first code of length len */ + int count; /* number of codes of length len */ + int index; /* index of first code of length len in symbol table */ + + code = first = index = 0; + for (len = 1; len <= MAXBITS; len++) { + code |= bits(s, 1); /* get next bit */ + count = h->count[len]; + if (code < first + count) /* if length len, return symbol */ + return h->symbol[index + (code - first)]; + index += count; /* else update for next length */ + first += count; + first <<= 1; + code <<= 1; + } + return -9; /* ran out of codes */ +} + +/* + * A faster version of decode() for real applications of this code. It's not + * as readable, but it makes puff() twice as fast. And it only makes the code + * a few percent larger. + */ +#else /* !SLOW */ +local int decode(struct state *s, struct huffman *h) +{ + int len; /* current number of bits in code */ + int code; /* len bits being decoded */ + int first; /* first code of length len */ + int count; /* number of codes of length len */ + int index; /* index of first code of length len in symbol table */ + int bitbuf; /* bits from stream */ + int left; /* bits left in next or left to process */ + short *next; /* next number of codes */ + + bitbuf = s->bitbuf; + left = s->bitcnt; + code = first = index = 0; + len = 1; + next = h->count + 1; + while (1) { + while (left--) { + code |= bitbuf & 1; + bitbuf >>= 1; + count = *next++; + if (code < first + count) { /* if length len, return symbol */ + s->bitbuf = bitbuf; + s->bitcnt = (s->bitcnt - len) & 7; + return h->symbol[index + (code - first)]; + } + index += count; /* else update for next length */ + first += count; + first <<= 1; + code <<= 1; + len++; + } + left = (MAXBITS+1) - len; + if (left == 0) break; + bitbuf = s->in[s->incnt++]; + if (left > 8) left = 8; + } + return -9; /* ran out of codes */ +} +#endif /* SLOW */ + + +local int construct(struct huffman *h, short *length, int n) +{ + int symbol; /* current symbol when stepping through length[] */ + int len; /* current length when stepping through h->count[] */ + int left; /* number of possible codes left of current length */ + short offs[MAXBITS+1]; /* offsets in symbol table for each length */ + + /* count number of codes of each length */ + for (len = 0; len <= MAXBITS; len++) + h->count[len] = 0; + for (symbol = 0; symbol < n; symbol++) + (h->count[length[symbol]])++; /* assumes lengths are within bounds */ + if (h->count[0] == n) /* no codes! */ + return 0; /* complete, but decode() will fail */ + + /* check for an over-subscribed or incomplete set of lengths */ + left = 1; /* one possible code of zero length */ + for (len = 1; len <= MAXBITS; len++) { + left <<= 1; /* one more bit, double codes left */ + left -= h->count[len]; /* deduct count from possible codes */ + if (left < 0) return left; /* over-subscribed--return negative */ + } /* left > 0 means incomplete */ + + /* generate offsets into symbol table for each length for sorting */ + offs[1] = 0; + for (len = 1; len < MAXBITS; len++) + offs[len + 1] = offs[len] + h->count[len]; + + /* + * put symbols in table sorted by length, by symbol order within each + * length + */ + for (symbol = 0; symbol < n; symbol++) + if (length[symbol] != 0) + h->symbol[offs[length[symbol]]++] = symbol; + + /* return zero for complete set, positive for incomplete set */ + return left; +} + + +local int codes(struct state *s, + struct huffman *lencode, + struct huffman *distcode) +{ + int symbol; /* decoded symbol */ + int len; /* length for copy */ + unsigned dist; /* distance for copy */ + static const short lens[29] = { /* Size base for length codes 257..285 */ + 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, + 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258}; + static const short lext[29] = { /* Extra bits for length codes 257..285 */ + 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, + 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0}; + static const short dists[30] = { /* Offset base for distance codes 0..29 */ + 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, + 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, + 8193, 12289, 16385, 24577}; + static const short dext[30] = { /* Extra bits for distance codes 0..29 */ + 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, + 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, + 12, 12, 13, 13}; + + /* decode literals and length/distance pairs */ + do { + symbol = decode(s, lencode); + if (symbol < 0) return symbol; /* invalid symbol */ + if (symbol < 256) { /* literal: symbol is the byte */ + /* write out the literal */ + if (s->out != NIL) { + if (s->outcnt == s->outlen) return 1; + s->out[s->outcnt] = symbol; + } + s->outcnt++; + } + else if (symbol > 256) { /* length */ + /* get and compute length */ + symbol -= 257; + if (symbol >= 29) return -9; /* invalid fixed code */ + len = lens[symbol] + bits(s, lext[symbol]); + + /* get and check distance */ + symbol = decode(s, distcode); + if (symbol < 0) return symbol; /* invalid symbol */ + dist = dists[symbol] + bits(s, dext[symbol]); + if (dist > s->outcnt) + return -10; /* distance too far back */ + + /* copy length bytes from distance bytes back */ + if (s->out != NIL) { + if (s->outcnt + len > s->outlen) return 1; + while (len--) { + s->out[s->outcnt] = s->out[s->outcnt - dist]; + s->outcnt++; + } + } + else + s->outcnt += len; + } + } while (symbol != 256); /* end of block symbol */ + + /* done with a valid fixed or dynamic block */ + return 0; +} + + +local int fixed(struct state *s) +{ + static int virgin = 1; + static short lencnt[MAXBITS+1], lensym[FIXLCODES]; + static short distcnt[MAXBITS+1], distsym[MAXDCODES]; + static struct huffman lencode = {lencnt, lensym}; + static struct huffman distcode = {distcnt, distsym}; + + /* build fixed huffman tables if first call (may not be thread safe) */ + if (virgin) { + int symbol; + short lengths[FIXLCODES]; + + /* literal/length table */ + for (symbol = 0; symbol < 144; symbol++) + lengths[symbol] = 8; + for (; symbol < 256; symbol++) + lengths[symbol] = 9; + for (; symbol < 280; symbol++) + lengths[symbol] = 7; + for (; symbol < FIXLCODES; symbol++) + lengths[symbol] = 8; + construct(&lencode, lengths, FIXLCODES); + + /* distance table */ + for (symbol = 0; symbol < MAXDCODES; symbol++) + lengths[symbol] = 5; + construct(&distcode, lengths, MAXDCODES); + + /* do this just once */ + virgin = 0; + } + + /* decode data until end-of-block code */ + return codes(s, &lencode, &distcode); +} + + +local int dynamic(struct state *s) +{ + int nlen, ndist, ncode; /* number of lengths in descriptor */ + int index; /* index of lengths[] */ + int err; /* construct() return value */ + short lengths[MAXCODES]; /* descriptor code lengths */ + short lencnt[MAXBITS+1], lensym[MAXLCODES]; /* lencode memory */ + short distcnt[MAXBITS+1], distsym[MAXDCODES]; /* distcode memory */ + struct huffman lencode = {lencnt, lensym}; /* length code */ + struct huffman distcode = {distcnt, distsym}; /* distance code */ + static const short order[19] = /* permutation of code length codes */ + {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; + + /* get number of lengths in each table, check lengths */ + nlen = bits(s, 5) + 257; + ndist = bits(s, 5) + 1; + ncode = bits(s, 4) + 4; + if (nlen > MAXLCODES || ndist > MAXDCODES) + return -3; /* bad counts */ + + /* read code length code lengths (really), missing lengths are zero */ + for (index = 0; index < ncode; index++) + lengths[order[index]] = bits(s, 3); + for (; index < 19; index++) + lengths[order[index]] = 0; + + /* build huffman table for code lengths codes (use lencode temporarily) */ + err = construct(&lencode, lengths, 19); + if (err != 0) return -4; /* require complete code set here */ + + /* read length/literal and distance code length tables */ + index = 0; + while (index < nlen + ndist) { + int symbol; /* decoded value */ + int len; /* last length to repeat */ + + symbol = decode(s, &lencode); + if (symbol < 0) + return symbol; /* invalid symbol */ + if (symbol < 16) /* length in 0..15 */ + lengths[index++] = symbol; + else { /* repeat instruction */ + len = 0; /* assume repeating zeros */ + switch(symbol)
+ {
+ case 16: { /* repeat last length 3..6 times */
+ if (index == 0) return -5; /* no last length! */
+ len = lengths[index - 1]; /* last length */
+ symbol = 3 + bits(s, 2);
+ break;
+ }
+ case 17: /* repeat zero 3..10 times */
+ symbol = 3 + bits(s, 3);
+ break;
+ default: /* == 18, repeat zero 11..138 times */
+ symbol = 11 + bits(s, 7);
+ break;
+ }
+ if ((index + symbol > nlen + ndist)) + return -6; /* too many lengths! */ + while (symbol--) /* repeat last or zero symbol times */ + lengths[index++] = len; + } + } + + /* check for end-of-block code -- there better be one! */
+ if (lengths[256] == 0)
+ return -9; + + /* build huffman table for literal/length codes */ + err = construct(&lencode, lengths, nlen); + if (err < 0 || (err > 0 && nlen - lencode.count[0] != 1)) + return -7; /* only allow incomplete codes if just one code */ + + /* build huffman table for distance codes */ + err = construct(&distcode, lengths + nlen, ndist); + if (err < 0 || (err > 0 && ndist - distcode.count[0] != 1)) + return -8; /* only allow incomplete codes if just one code */ + + /* decode data until end-of-block code */ + return codes(s, &lencode, &distcode); +} + + +void _acrtused () { } + +// Decompress deflated data int far main (
unsigned char *dest, /* pointer to destination pointer */
unsigned int destlen, /* amount of output space */
- unsigned char *source) /* pointer to source data pointer */
+ unsigned char *source, /* pointer to source data pointer */
+ unsigned int sourcelen)
{
struct state s; /* input/output state */
int last, type; /* block information */
@@ -417,6 +439,7 @@ int far main ( /* initialize input state */
s.in = source;
+ s.inlen = sourcelen;
s.incnt = 0;
s.bitbuf = 0;
s.bitcnt = 0;
@@ -425,12 +448,24 @@ int far main ( do {
last = bits(&s, 1); /* one if last block */
type = bits(&s, 2); /* block type 0..3 */
- err = type == 0 ? stored(&s) :
- (type == 1 ? fixed(&s) :
- (type == 2 ? dynamic(&s) :
- -1)); /* type == 3, invalid */
+ switch(type)
+ {
+ case 0:
+ err = stored(&s);
+ break;
+ case 1:
+ err = fixed(&s);
+ break;
+ case 2:
+ err = dynamic(&s);
+ break;
+ default:
+ err = -1; /* type == 3, invalid */
+ break;
+ }
+
if (err != 0) break; /* return with error */
} while (!last);
return err;
-}
+} |