VeraCrypt
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-rw-r--r--src/Boot/Windows/Decompressor.c436
1 files changed, 436 insertions, 0 deletions
diff --git a/src/Boot/Windows/Decompressor.c b/src/Boot/Windows/Decompressor.c
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+/*
+ 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
+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 */
+{
+ struct state s; /* input/output state */
+ int last, type; /* block information */
+ int err; /* return value */
+
+ /* initialize output state */
+ s.out = dest;
+ s.outlen = destlen; /* ignored if dest is NIL */
+ s.outcnt = 0;
+
+ /* initialize input state */
+ s.in = source;
+ s.incnt = 0;
+ s.bitbuf = 0;
+ s.bitcnt = 0;
+
+ /* process blocks until last block or error */
+ 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 */
+ if (err != 0) break; /* return with error */
+ } while (!last);
+
+ return err;
+}