r6129: - add our own MSZIP decompression implementation

  (taken from cabextract.c from KDE)
  this code maybe need to be rewritten and the
  compression side needs to be done,
  but for now it seems to works

- remove the dependency to zlib

metze
(This used to be commit 5e8558c5b4365a494aa054c3e08d4084b319e6e5)

2 files changed, 711 insertions, 0 deletions

diff --git a/source4/lib/compression/mszip.c b/source4/lib/compression/mszip.c
new file mode 100644
index 0000000000..97b53f56ad
--- /dev/null
+++ b/source4/lib/compression/mszip.c
@@ -0,0 +1,677 @@
+/* mszip decompression - based on cabextract.c code from
+ * Stuart Caie
+ *
+ * adapted for Samba by Andrew Tridgell and Stefan Metzmacher 2005
+ *
+ * (C) 2000-2001 Stuart Caie <kyzer@4u.net>
+ * reaktivate-specifics by Malte Starostik <malte@kde.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "includes.h"
+#include "lib/compression/mszip.h"
+
+/*--------------------------------------------------------------------------*/
+/* our archiver information / state */
+
+/* MSZIP stuff */
+#define ZIPWSIZE 	0x8000  /* window size */
+#define ZIPLBITS	9	/* bits in base literal/length lookup table */
+#define ZIPDBITS	6	/* bits in base distance lookup table */
+#define ZIPBMAX		16      /* maximum bit length of any code */
+#define ZIPN_MAX	288     /* maximum number of codes in any set */
+
+struct Ziphuft {
+  uint8_t e;                /* number of extra bits or operation */
+  uint8_t b;                /* number of bits in this code or subcode */
+  union {
+    uint16_t n;              /* literal, length base, or distance base */
+    struct Ziphuft *t;    /* pointer to next level of table */
+  } v;
+};
+
+struct ZIPstate {
+    uint32_t window_posn;     /* current offset within the window        */
+    uint32_t bb;              /* bit buffer */
+    uint32_t bk;              /* bits in bit buffer */
+    uint32_t ll[288+32];	   /* literal/length and distance code lengths */
+    uint32_t c[ZIPBMAX+1];    /* bit length count table */
+    int32_t  lx[ZIPBMAX+1];   /* memory for l[-1..ZIPBMAX-1] */
+    struct Ziphuft *u[ZIPBMAX];         	/* table stack */
+    uint32_t v[ZIPN_MAX];     /* values in order of bit length */
+    uint32_t x[ZIPBMAX+1];    /* bit offsets, then code stack */
+    uint8_t *inpos;
+};
+
+/* generic stuff */
+#define CAB(x) (decomp_state->x)
+#define ZIP(x) (decomp_state->methods.zip.x)
+
+/* CAB data blocks are <= 32768 bytes in uncompressed form. Uncompressed
+ * blocks have zero growth. MSZIP guarantees that it won't grow above
+ * uncompressed size by more than 12 bytes. LZX guarantees it won't grow
+ * more than 6144 bytes.
+ */
+#define CAB_BLOCKMAX (32768)
+#define CAB_INPUTMAX (CAB_BLOCKMAX+6144)
+
+struct decomp_state {
+  struct folder *current; /* current folder we're extracting from  */
+  uint32_t offset;           /* uncompressed offset within folder     */
+  uint8_t *outpos;          /* (high level) start of data to use up  */
+  uint16_t outlen;           /* (high level) amount of data to use up */
+  uint16_t split;            /* at which split in current folder?     */
+  int (*decompress)(int, int); /* the chosen compression func      */
+  uint8_t inbuf[CAB_INPUTMAX+2]; /* +2 for lzx bitbuffer overflows!  */
+  uint8_t outbuf[CAB_BLOCKMAX];
+  union {
+    struct ZIPstate zip;
+  } methods;
+};
+
+
+/* MSZIP decruncher */
+
+/* Dirk Stoecker wrote the ZIP decoder, based on the InfoZip deflate code */
+
+/* Tables for deflate from PKZIP's appnote.txt. */
+static const uint8_t Zipborder[] = /* Order of the bit length code lengths */
+{ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+static const uint16_t Zipcplens[] = /* Copy lengths for literal 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, 0, 0};
+static const uint16_t Zipcplext[] = /* Extra bits for literal 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, 99, 99}; /* 99==invalid */
+static const uint16_t Zipcpdist[] = /* Copy offsets 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 uint16_t Zipcpdext[] = /* Extra bits for distance codes */
+{ 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};
+
+/* And'ing with Zipmask[n] masks the lower n bits */
+static const uint16_t Zipmask[17] = {
+ 0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+ 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
+};
+
+#define ZIPNEEDBITS(n) {while(k<(n)){int32_t c=*(ZIP(inpos)++);\
+    b|=((uint32_t)c)<<k;k+=8;}}
+#define ZIPDUMPBITS(n) {b>>=(n);k-=(n);}
+
+static void Ziphuft_free(struct Ziphuft *t)
+{
+  register struct Ziphuft *p, *q;
+
+  /* Go through linked list, freeing from the allocated (t[-1]) address. */
+  p = t;
+  while (p != (struct Ziphuft *)NULL)
+  {
+    q = (--p)->v.t;
+    free(p);
+    p = q;
+  } 
+}
+
+static int32_t Ziphuft_build(struct decomp_state *decomp_state,
+			  uint32_t *b, uint32_t n, uint32_t s, const uint16_t *d, const uint16_t *e,
+			  struct Ziphuft **t, int32_t *m)
+{
+  uint32_t a;                   	/* counter for codes of length k */
+  uint32_t el;                  	/* length of EOB code (value 256) */
+  uint32_t f;                   	/* i repeats in table every f entries */
+  int32_t g;                    	/* maximum code length */
+  int32_t h;                    	/* table level */
+  register uint32_t i;          	/* counter, current code */
+  register uint32_t j;          	/* counter */
+  register int32_t k;           	/* number of bits in current code */
+  int32_t *l;               	/* stack of bits per table */
+  register uint32_t *p;         	/* pointer into ZIP(c)[],ZIP(b)[],ZIP(v)[] */
+  register struct Ziphuft *q;   /* points to current table */
+  struct Ziphuft r;             /* table entry for structure assignment */
+  register int32_t w;              /* bits before this table == (l * h) */
+  uint32_t *xp;                 	/* pointer into x */
+  int32_t y;                       /* number of dummy codes added */
+  uint32_t z;                   	/* number of entries in current table */
+
+  l = ZIP(lx)+1;
+
+  /* Generate counts for each bit length */
+  el = n > 256 ? b[256] : ZIPBMAX; /* set length of EOB code, if any */
+
+  for(i = 0; i < ZIPBMAX+1; ++i)
+    ZIP(c)[i] = 0;
+  p = b;  i = n;
+  do
+  {
+    ZIP(c)[*p]++; p++;               /* assume all entries <= ZIPBMAX */
+  } while (--i);
+  if (ZIP(c)[0] == n)                /* null input--all zero length codes */
+  {
+    *t = (struct Ziphuft *)NULL;
+    *m = 0;
+    return 0;
+  }
+
+  /* Find minimum and maximum length, bound *m by those */
+  for (j = 1; j <= ZIPBMAX; j++)
+    if (ZIP(c)[j])
+      break;
+  k = j;                        /* minimum code length */
+  if ((uint32_t)*m < j)
+    *m = j;
+  for (i = ZIPBMAX; i; i--)
+    if (ZIP(c)[i])
+      break;
+  g = i;                        /* maximum code length */
+  if ((uint32_t)*m > i)
+    *m = i;
+
+  /* Adjust last length count to fill out codes, if needed */
+  for (y = 1 << j; j < i; j++, y <<= 1)
+    if ((y -= ZIP(c)[j]) < 0)
+      return 2;                 /* bad input: more codes than bits */
+  if ((y -= ZIP(c)[i]) < 0)
+    return 2;
+  ZIP(c)[i] += y;
+
+  /* Generate starting offsets int32_to the value table for each length */
+  ZIP(x)[1] = j = 0;
+  p = ZIP(c) + 1;  xp = ZIP(x) + 2;
+  while (--i)
+  {                 /* note that i == g from above */
+    *xp++ = (j += *p++);
+  }
+
+  /* Make a table of values in order of bit lengths */
+  p = b;  i = 0;
+  do{
+    if ((j = *p++) != 0)
+      ZIP(v)[ZIP(x)[j]++] = i;
+  } while (++i < n);
+
+
+  /* Generate the Huffman codes and for each, make the table entries */
+  ZIP(x)[0] = i = 0;                 /* first Huffman code is zero */
+  p = ZIP(v);                        /* grab values in bit order */
+  h = -1;                       /* no tables yet--level -1 */
+  w = l[-1] = 0;                /* no bits decoded yet */
+  ZIP(u)[0] = (struct Ziphuft *)NULL;   /* just to keep compilers happy */
+  q = (struct Ziphuft *)NULL;      /* ditto */
+  z = 0;                        /* ditto */
+
+  /* go through the bit lengths (k already is bits in shortest code) */
+  for (; k <= g; k++)
+  {
+    a = ZIP(c)[k];
+    while (a--)
+    {
+      /* here i is the Huffman code of length k bits for value *p */
+      /* make tables up to required level */
+      while (k > w + l[h])
+      {
+        w += l[h++];            /* add bits already decoded */
+
+        /* compute minimum size table less than or equal to *m bits */
+        z = (z = g - w) > (uint32_t)*m ? *m : z;        /* upper limit */
+        if ((f = 1 << (j = k - w)) > a + 1)     /* try a k-w bit table */
+        {                       /* too few codes for k-w bit table */
+          f -= a + 1;           /* deduct codes from patterns left */
+          xp = ZIP(c) + k;
+          while (++j < z)       /* try smaller tables up to z bits */
+          {
+            if ((f <<= 1) <= *++xp)
+              break;            /* enough codes to use up j bits */
+            f -= *xp;           /* else deduct codes from patterns */
+          }
+        }
+        if ((uint32_t)w + j > el && (uint32_t)w < el)
+          j = el - w;           /* make EOB code end at table */
+        z = 1 << j;             /* table entries for j-bit table */
+        l[h] = j;               /* set table size in stack */
+
+        /* allocate and link in new table */
+        if (!(q = (struct Ziphuft *) malloc((z + 1)*sizeof(struct Ziphuft))))
+        {
+          if(h)
+            Ziphuft_free(ZIP(u)[0]);
+          return 3;             /* not enough memory */
+        }
+        *t = q + 1;             /* link to list for Ziphuft_free() */
+        *(t = &(q->v.t)) = (struct Ziphuft *)NULL;
+        ZIP(u)[h] = ++q;             /* table starts after link */
+
+        /* connect to last table, if there is one */
+        if (h)
+        {
+          ZIP(x)[h] = i;             /* save pattern for backing up */
+          r.b = (uint8_t)l[h-1];    /* bits to dump before this table */
+          r.e = (uint8_t)(16 + j);  /* bits in this table */
+          r.v.t = q;            /* pointer to this table */
+          j = (i & ((1 << w) - 1)) >> (w - l[h-1]);
+          ZIP(u)[h-1][j] = r;        /* connect to last table */
+        }
+      }
+
+      /* set up table entry in r */
+      r.b = (uint8_t)(k - w);
+      if (p >= ZIP(v) + n)
+        r.e = 99;               /* out of values--invalid code */
+      else if (*p < s)
+      {
+        r.e = (uint8_t)(*p < 256 ? 16 : 15);    /* 256 is end-of-block code */
+        r.v.n = *p++;           /* simple code is just the value */
+      }
+      else
+      {
+        r.e = (uint8_t)e[*p - s];   /* non-simple--look up in lists */
+        r.v.n = d[*p++ - s];
+      }
+
+      /* fill code-like entries with r */
+      f = 1 << (k - w);
+      for (j = i >> w; j < z; j += f)
+        q[j] = r;
+
+      /* backwards increment the k-bit code i */
+      for (j = 1 << (k - 1); i & j; j >>= 1)
+        i ^= j;
+      i ^= j;
+
+      /* backup over finished tables */
+      while ((i & ((1 << w) - 1)) != ZIP(x)[h])
+        w -= l[--h];            /* don't need to update q */
+    }
+  }
+
+  /* return actual size of base table */
+  *m = l[0];
+
+  /* Return true (1) if we were given an incomplete table */
+  return y != 0 && g != 1;
+}
+
+static int32_t Zipinflate_codes(struct decomp_state *decomp_state,
+			     struct Ziphuft *tl, struct Ziphuft *td,
+			     int32_t bl, int32_t bd)
+{
+  register uint32_t e;  /* table entry flag/number of extra bits */
+  uint32_t n, d;        /* length and index for copy */
+  uint32_t w;           /* current window position */
+  struct Ziphuft *t; /* pointer to table entry */
+  uint32_t ml, md;      /* masks for bl and bd bits */
+  register uint32_t b;  /* bit buffer */
+  register uint32_t k;  /* number of bits in bit buffer */
+
+  DEBUG(10,("Zipinflate_codes\n"));
+
+  /* make local copies of globals */
+  b = ZIP(bb);                       /* initialize bit buffer */
+  k = ZIP(bk);
+  w = ZIP(window_posn);                       /* initialize window position */
+
+  /* inflate the coded data */
+  ml = Zipmask[bl];           	/* precompute masks for speed */
+  md = Zipmask[bd];
+
+  for(;;)
+  {
+    ZIPNEEDBITS((uint32_t)bl)
+    if((e = (t = tl + ((uint32_t)b & ml))->e) > 16)
+      do
+      {
+        if (e == 99)
+          return 1;
+        ZIPDUMPBITS(t->b)
+        e -= 16;
+        ZIPNEEDBITS(e)
+      } while ((e = (t = t->v.t + ((uint32_t)b & Zipmask[e]))->e) > 16);
+    ZIPDUMPBITS(t->b)
+    if (w >= 32768) break;
+    if (e == 16)                /* then it's a literal */
+      CAB(outbuf)[w++] = (uint8_t)t->v.n;
+    else                        /* it's an EOB or a length */
+    {
+      /* exit if end of block */
+      if(e == 15)
+        break;
+
+      /* get length of block to copy */
+      ZIPNEEDBITS(e)
+      n = t->v.n + ((uint32_t)b & Zipmask[e]);
+      ZIPDUMPBITS(e);
+
+      /* decode distance of block to copy */
+      ZIPNEEDBITS((uint32_t)bd)
+      if ((e = (t = td + ((uint32_t)b & md))->e) > 16)
+        do {
+          if (e == 99)
+            return 1;
+          ZIPDUMPBITS(t->b)
+          e -= 16;
+          ZIPNEEDBITS(e)
+        } while ((e = (t = t->v.t + ((uint32_t)b & Zipmask[e]))->e) > 16);
+      ZIPDUMPBITS(t->b)
+      ZIPNEEDBITS(e)
+      d = w - t->v.n - ((uint32_t)b & Zipmask[e]);
+      ZIPDUMPBITS(e)
+      do
+      {
+        n -= (e = (e = ZIPWSIZE - ((d &= ZIPWSIZE-1) > w ? d : w)) > n ?n:e);
+        do
+        {
+          CAB(outbuf)[w++] = CAB(outbuf)[d++];
+        } while (--e);
+      } while (n);
+    }
+  }
+
+  /* restore the globals from the locals */
+  ZIP(window_posn) = w;              /* restore global window pointer */
+  ZIP(bb) = b;                       /* restore global bit buffer */
+  ZIP(bk) = k;
+
+  /* done */
+  return 0;
+}
+
+/* "decompress" an inflated type 0 (stored) block. */
+static int32_t Zipinflate_stored(struct decomp_state *decomp_state)
+{
+  uint32_t n;           /* number of bytes in block */
+  uint32_t w;           /* current window position */
+  register uint32_t b;  /* bit buffer */
+  register uint32_t k;  /* number of bits in bit buffer */
+
+  /* make local copies of globals */
+  b = ZIP(bb);                       /* initialize bit buffer */
+  k = ZIP(bk);
+  w = ZIP(window_posn);              /* initialize window position */
+
+  /* go to byte boundary */
+  n = k & 7;
+  ZIPDUMPBITS(n);
+
+  /* get the length and its complement */
+  ZIPNEEDBITS(16)
+  n = ((uint32_t)b & 0xffff);
+  ZIPDUMPBITS(16)
+  ZIPNEEDBITS(16)
+  if (n != (uint32_t)((~b) & 0xffff))
+    return 1;                   /* error in compressed data */
+  ZIPDUMPBITS(16)
+
+  /* read and output the compressed data */
+  while(n--)
+  {
+    ZIPNEEDBITS(8)
+    CAB(outbuf)[w++] = (uint8_t)b;
+    ZIPDUMPBITS(8)
+  }
+
+  /* restore the globals from the locals */
+  ZIP(window_posn) = w;              /* restore global window pointer */
+  ZIP(bb) = b;                       /* restore global bit buffer */
+  ZIP(bk) = k;
+  return 0;
+}
+
+static int32_t Zipinflate_fixed(struct decomp_state *decomp_state)
+{
+  struct Ziphuft *fixed_tl;
+  struct Ziphuft *fixed_td;
+  int32_t fixed_bl, fixed_bd;
+  int32_t i;                /* temporary variable */
+  uint32_t *l;
+
+  l = ZIP(ll);
+
+  /* literal table */
+  for(i = 0; i < 144; i++)
+    l[i] = 8;
+  for(; i < 256; i++)
+    l[i] = 9;
+  for(; i < 280; i++)
+    l[i] = 7;
+  for(; i < 288; i++)          /* make a complete, but wrong code set */
+    l[i] = 8;
+  fixed_bl = 7;
+  if((i = Ziphuft_build(decomp_state, l, 288, 257, Zipcplens, Zipcplext, &fixed_tl, &fixed_bl)))
+    return i;
+
+  /* distance table */
+  for(i = 0; i < 30; i++)      /* make an incomplete code set */
+    l[i] = 5;
+  fixed_bd = 5;
+  if((i = Ziphuft_build(decomp_state, l, 30, 0, Zipcpdist, Zipcpdext, &fixed_td, &fixed_bd)) > 1)
+  {
+    Ziphuft_free(fixed_tl);
+    return i;
+  }
+
+  /* decompress until an end-of-block code */
+  i = Zipinflate_codes(decomp_state, fixed_tl, fixed_td, fixed_bl, fixed_bd);
+
+  Ziphuft_free(fixed_td);
+  Ziphuft_free(fixed_tl);
+  return i;
+}
+
+/* decompress an inflated type 2 (dynamic Huffman codes) block. */
+static int32_t Zipinflate_dynamic(struct decomp_state *decomp_state)
+{
+  int32_t i;          	/* temporary variables */
+  uint32_t j;
+  uint32_t *ll;
+  uint32_t l;           	/* last length */
+  uint32_t m;           	/* mask for bit lengths table */
+  uint32_t n;           	/* number of lengths to get */
+  struct Ziphuft *tl;      /* literal/length code table */
+  struct Ziphuft *td;      /* distance code table */
+  int32_t bl;              /* lookup bits for tl */
+  int32_t bd;              /* lookup bits for td */
+  uint32_t nb;          	/* number of bit length codes */
+  uint32_t nl;          	/* number of literal/length codes */
+  uint32_t nd;          	/* number of distance codes */
+  register uint32_t b;     /* bit buffer */
+  register uint32_t k;	/* number of bits in bit buffer */
+
+  /* make local bit buffer */
+  b = ZIP(bb);
+  k = ZIP(bk);
+  ll = ZIP(ll);
+
+  /* read in table lengths */
+  ZIPNEEDBITS(5)
+  nl = 257 + ((uint32_t)b & 0x1f);      /* number of literal/length codes */
+  ZIPDUMPBITS(5)
+  ZIPNEEDBITS(5)
+  nd = 1 + ((uint32_t)b & 0x1f);        /* number of distance codes */
+  ZIPDUMPBITS(5)
+  ZIPNEEDBITS(4)
+  nb = 4 + ((uint32_t)b & 0xf);         /* number of bit length codes */
+  ZIPDUMPBITS(4)
+  if(nl > 288 || nd > 32)
+    return 1;                   /* bad lengths */
+
+  /* read in bit-length-code lengths */
+  for(j = 0; j < nb; j++)
+  {
+    ZIPNEEDBITS(3)
+    ll[Zipborder[j]] = (uint32_t)b & 7;
+    ZIPDUMPBITS(3)
+  }
+  for(; j < 19; j++)
+    ll[Zipborder[j]] = 0;
+
+  /* build decoding table for trees--single level, 7 bit lookup */
+  bl = 7;
+  if((i = Ziphuft_build(decomp_state, ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
+  {
+    if(i == 1)
+      Ziphuft_free(tl);
+    return i;                   /* incomplete code set */
+  }
+
+  /* read in literal and distance code lengths */
+  n = nl + nd;
+  m = Zipmask[bl];
+  i = l = 0;
+  while((uint32_t)i < n)
+  {
+    ZIPNEEDBITS((uint32_t)bl)
+    j = (td = tl + ((uint32_t)b & m))->b;
+    ZIPDUMPBITS(j)
+    j = td->v.n;
+    if (j < 16)                 /* length of code in bits (0..15) */
+      ll[i++] = l = j;          /* save last length in l */
+    else if (j == 16)           /* repeat last length 3 to 6 times */
+    {
+      ZIPNEEDBITS(2)
+      j = 3 + ((uint32_t)b & 3);
+      ZIPDUMPBITS(2)
+      if((uint32_t)i + j > n)
+        return 1;
+      while (j--)
+        ll[i++] = l;
+    }
+    else if (j == 17)           /* 3 to 10 zero length codes */
+    {
+      ZIPNEEDBITS(3)
+      j = 3 + ((uint32_t)b & 7);
+      ZIPDUMPBITS(3)
+      if ((uint32_t)i + j > n)
+        return 1;
+      while (j--)
+        ll[i++] = 0;
+      l = 0;
+    }
+    else                        /* j == 18: 11 to 138 zero length codes */
+    {
+      ZIPNEEDBITS(7)
+      j = 11 + ((uint32_t)b & 0x7f);
+      ZIPDUMPBITS(7)
+      if ((uint32_t)i + j > n)
+        return 1;
+      while (j--)
+        ll[i++] = 0;
+      l = 0;
+    }
+  }
+
+  /* free decoding table for trees */
+  Ziphuft_free(tl);
+
+  /* restore the global bit buffer */
+  ZIP(bb) = b;
+  ZIP(bk) = k;
+
+  /* build the decoding tables for literal/length and distance codes */
+  bl = ZIPLBITS;
+  if((i = Ziphuft_build(decomp_state, ll, nl, 257, Zipcplens, Zipcplext, &tl, &bl)) != 0)
+  {
+    if(i == 1)
+      Ziphuft_free(tl);
+    return i;                   /* incomplete code set */
+  }
+  bd = ZIPDBITS;
+  Ziphuft_build(decomp_state, ll + nl, nd, 0, Zipcpdist, Zipcpdext, &td, &bd);
+
+  /* decompress until an end-of-block code */
+  if(Zipinflate_codes(decomp_state, tl, td, bl, bd))
+    return 1;
+
+  /* free the decoding tables, return */
+  Ziphuft_free(tl);
+  Ziphuft_free(td);
+  return 0;
+}
+
+/* e == last block flag */
+static int32_t Zipinflate_block(struct decomp_state *decomp_state, int32_t *e)
+{ /* decompress an inflated block */
+  uint32_t t;           	/* block type */
+  register uint32_t b;     /* bit buffer */
+  register uint32_t k;     /* number of bits in bit buffer */
+
+  DEBUG(10,("Zipinflate_block\n"));
+
+  /* make local bit buffer */
+  b = ZIP(bb);
+  k = ZIP(bk);
+
+  /* read in last block bit */
+  ZIPNEEDBITS(1)
+  *e = (int32_t)b & 1;
+  ZIPDUMPBITS(1)
+
+  /* read in block type */
+  ZIPNEEDBITS(2)
+  t = (uint32_t)b & 3;
+  ZIPDUMPBITS(2)
+
+  /* restore the global bit buffer */
+  ZIP(bb) = b;
+  ZIP(bk) = k;
+
+  DEBUG(10,("inflate type %d\n", t));
+
+  /* inflate that block type */
+  if(t == 2)
+    return Zipinflate_dynamic(decomp_state);
+  if(t == 0)
+    return Zipinflate_stored(decomp_state);
+  if(t == 1)
+    return Zipinflate_fixed(decomp_state);
+  /* bad block type */
+  return 2;
+}
+
+struct decomp_state *ZIPdecomp_state(TALLOC_CTX *mem_ctx)
+{
+	return talloc_zero(mem_ctx, struct decomp_state);
+}
+
+int ZIPdecompress(struct decomp_state *decomp_state, DATA_BLOB *inbuf, DATA_BLOB *outbuf)
+{
+	int32_t e = 0;/* last block flag */
+
+	ZIP(inpos) = CAB(inbuf);
+	ZIP(bb) = ZIP(bk) = ZIP(window_posn) = 0;
+
+	if (inbuf->length > sizeof(decomp_state->inbuf)) return DECR_INPUT;
+
+	if (outbuf->length > sizeof(decomp_state->outbuf)) return DECR_OUTPUT;
+
+	if (outbuf->length > ZIPWSIZE) return DECR_DATAFORMAT;
+
+	memcpy(decomp_state->inbuf, inbuf->data, inbuf->length);
+
+	/* CK = Chris Kirmse, official Microsoft purloiner */
+	if (ZIP(inpos)[0] != 'C' || ZIP(inpos)[1] != 'K') return DECR_ILLEGALDATA;
+	ZIP(inpos) += 2;
+
+	while (!e) {
+		if (Zipinflate_block(decomp_state, &e)) {
+			return DECR_ILLEGALDATA;
+		}
+	}
+
+	memcpy(outbuf->data, decomp_state->outbuf, outbuf->length);
+
+	return DECR_OK;
+}
diff --git a/source4/lib/compression/mszip.h b/source4/lib/compression/mszip.h
new file mode 100644
index 0000000000..cc9769f73a
--- /dev/null
+++ b/source4/lib/compression/mszip.h
@@ -0,0 +1,34 @@
+/* mszip decompression - based on cabextract.c code from
+ * Stuart Caie
+ *
+ * adapted for Samba by Andrew Tridgell and Stefan Metzmacher 2005
+ *
+ * (C) 2000-2001 Stuart Caie <kyzer@4u.net>
+ * reaktivate-specifics by Malte Starostik <malte@kde.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+struct decomp_state;
+struct decomp_state *ZIPdecomp_state(TALLOC_CTX *mem_ctx);
+
+#define DECR_OK           (0)
+#define DECR_DATAFORMAT   (1)
+#define DECR_ILLEGALDATA  (2)
+#define DECR_NOMEMORY     (3)
+#define DECR_CHECKSUM     (4)
+#define DECR_INPUT        (5)
+#define DECR_OUTPUT       (6)
+int ZIPdecompress(struct decomp_state *decomp_state, DATA_BLOB *inbuf, DATA_BLOB *outbuf);