zlib 1.2.3.4

contrib/infback9/infback9.c

@@ -1,5 +1,5 @@
 /* infback9.c -- inflate deflate64 data using a call-back interface
- * Copyright (C) 1995-2006 Mark Adler
+ * Copyright (C) 1995-2008 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -433,7 +433,16 @@ void FAR *out_desc;
             /* handle error breaks in while */
             if (mode == BAD) break;
 
-            /* build code tables */
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftree9.h
+               concerning the ENOUGH constants, which depend on those values */
             state->next = state->codes;
             lencode = (code const FAR *)(state->next);
             lenbits = 9;

contrib/infback9/inftree9.c

@@ -1,5 +1,5 @@
 /* inftree9.c -- generate Huffman trees for efficient decoding
- * Copyright (C) 1995-2006 Mark Adler
+ * Copyright (C) 1995-2008 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -9,7 +9,7 @@
 #define MAXBITS 15
 
 const char inflate9_copyright[] =
-   " inflate9 1.2.3.3 Copyright 1995-2006 Mark Adler ";
+   " inflate9 1.2.3.4 Copyright 1995-2008 Mark Adler ";
 /*
   If you use the zlib library in a product, an acknowledgment is welcome
   in the documentation of your product. If for some reason you cannot
@@ -64,7 +64,7 @@ unsigned short FAR *work;
     static const unsigned short lext[31] = { /* Length codes 257..285 extra */
         128, 128, 128, 128, 128, 128, 128, 128, 129, 129, 129, 129,
         130, 130, 130, 130, 131, 131, 131, 131, 132, 132, 132, 132,
-        133, 133, 133, 133, 144, 201, 203};
+        133, 133, 133, 133, 144, 72, 200};
     static const unsigned short dbase[32] = { /* Distance codes 0..31 base */
         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49,
         65, 97, 129, 193, 257, 385, 513, 769, 1025, 1537, 2049, 3073,
@@ -160,11 +160,10 @@ unsigned short FAR *work;
        entered in the tables.
 
        used keeps track of how many table entries have been allocated from the
-       provided *table space.  It is checked when a LENS table is being made
-       against the space in *table, ENOUGH, minus the maximum space needed by
-       the worst case distance code, MAXD.  This should never happen, but the
-       sufficiency of ENOUGH has not been proven exhaustively, hence the check.
-       This assumes that when type == LENS, bits == 9.
+       provided *table space.  It is checked for LENS and DIST tables against
+       the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in
+       the initial root table size constants.  See the comments in inftree9.h
+       for more information.
 
        sym increments through all symbols, and the loop terminates when
        all codes of length max, i.e. all codes, have been processed.  This
@@ -203,7 +202,8 @@ unsigned short FAR *work;
     mask = used - 1;            /* mask for comparing low */
 
     /* check available table space */
-    if (type == LENS && used >= ENOUGH - MAXD)
+    if ((type == LENS && used >= ENOUGH_LENS) ||
+        (type == DISTS && used >= ENOUGH_DISTS))
         return 1;
 
     /* process all codes and make table entries */
@@ -270,7 +270,8 @@ unsigned short FAR *work;
 
             /* check for enough space */
             used += 1U << curr;
-            if (type == LENS && used >= ENOUGH - MAXD)
+            if ((type == LENS && used >= ENOUGH_LENS) ||
+                (type == DISTS && used >= ENOUGH_DISTS))
                 return 1;
 
             /* point entry in root table to sub-table */

contrib/infback9/inftree9.h

@@ -1,5 +1,5 @@
 /* inftree9.h -- header to use inftree9.c
- * Copyright (C) 1995-2003 Mark Adler
+ * Copyright (C) 1995-2008 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -35,15 +35,21 @@ typedef struct {
     01000000 - invalid code
  */
 
-/* Maximum size of dynamic tree.  The maximum found in a long but non-
-   exhaustive search was 1444 code structures (852 for length/literals
-   and 592 for distances, the latter actually the result of an
-   exhaustive search).  The true maximum is not known, but the value
-   below is more than safe. */
-#define ENOUGH 2048
-#define MAXD 592
+/* Maximum size of the dynamic table.  The maximum number of code structures is
+   1446, which is the sum of 852 for literal/length codes and 594 for distance
+   codes.  These values were found by exhaustive searches using the program
+   examples/enough.c found in the zlib distribtution.  The arguments to that
+   program are the number of symbols, the initial root table size, and the
+   maximum bit length of a code.  "enough 286 9 15" for literal/length codes
+   returns returns 852, and "enough 32 6 15" for distance codes returns 594.
+   The initial root table size (9 or 6) is found in the fifth argument of the
+   inflate_table() calls in infback9.c.  If the root table size is changed,
+   then these maximum sizes would be need to be recalculated and updated. */
+#define ENOUGH_LENS 852
+#define ENOUGH_DISTS 594
+#define ENOUGH (ENOUGH_LENS+ENOUGH_DISTS)
 
-/* Type of code to build for inftable() */
+/* Type of code to build for inflate_table9() */
 typedef enum {
     CODES,
     LENS,