Fix uncompress() to work on lengths more than a maximum unsigned.

1 files changed, 41 insertions, 20 deletions

diff --git a/uncompr.c b/uncompr.c
index 242e949..2ec3eba 100644
--- a/uncompr.c
+++ b/uncompr.c
@@ -1,5 +1,5 @@
 /* uncompr.c -- decompress a memory buffer
- * Copyright (C) 1995-2003, 2010 Jean-loup Gailly.
+ * Copyright (C) 1995-2003, 2010, 2014 Jean-loup Gailly, Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -19,7 +19,8 @@
 
      uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
    enough memory, Z_BUF_ERROR if there was not enough room in the output
-   buffer, or Z_DATA_ERROR if the input data was corrupted.
+   buffer, or Z_DATA_ERROR if the input data was corrupted, including if the
+   input data is an incomplete zlib stream.
 */
 int ZEXPORT uncompress (dest, destLen, source, sourceLen)
     Bytef *dest;
@@ -29,31 +30,51 @@ int ZEXPORT uncompress (dest, destLen, source, sourceLen)
 {
     z_stream stream;
     int err;
+    const uInt max = -1;
+    uLong left;
+    Byte buf[1];    /* for detection of incomplete stream when *destLen == 0 */
 
-    stream.next_in = (z_const Bytef *)source;
-    stream.avail_in = (uInt)sourceLen;
-    /* Check for source > 64K on 16-bit machine: */
-    if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
-
-    stream.next_out = dest;
-    stream.avail_out = (uInt)*destLen;
-    if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
+    if (*destLen) {
+        left = *destLen;
+        *destLen = 0;
+    }
+    else {
+        left = 1;
+        dest = buf;
+    }
 
+    stream.next_in = (z_const Bytef *)source;
+    stream.avail_in = 0;
     stream.zalloc = (alloc_func)0;
     stream.zfree = (free_func)0;
+    stream.opaque = (voidpf)0;
 
     err = inflateInit(&stream);
     if (err != Z_OK) return err;
 
-    err = inflate(&stream, Z_FINISH);
-    if (err != Z_STREAM_END) {
-        inflateEnd(&stream);
-        if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0))
-            return Z_DATA_ERROR;
-        return err;
-    }
-    *destLen = stream.total_out;
+    stream.next_out = dest;
+    stream.avail_out = 0;
+
+    do {
+        if (stream.avail_out == 0) {
+            stream.avail_out = left > (uLong)max ? max : (uInt)left;
+            left -= stream.avail_out;
+        }
+        if (stream.avail_in == 0) {
+            stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen;
+            sourceLen -= stream.avail_in;
+        }
+        err = inflate(&stream, Z_NO_FLUSH);
+    } while (err == Z_OK);
+
+    if (dest != buf)
+        *destLen = stream.total_out;
+    else if (stream.total_out && err == Z_BUF_ERROR)
+        left = 1;
 
-    err = inflateEnd(&stream);
-    return err;
+    inflateEnd(&stream);
+    return err == Z_STREAM_END ? Z_OK :
+           err == Z_NEED_DICT ? Z_DATA_ERROR  :
+           err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
+           err;
 }