1 files changed, 66 insertions, 47 deletions

diff --git a/lzip_index.c b/lzip_index.c
index 44c7b17..ca4df8d 100644
--- a/lzip_index.c
+++ b/lzip_index.c
@@ -1,28 +1,28 @@
-/*  Lunzip - Decompressor for the lzip format
-    Copyright (C) 2010-2019 Antonio Diaz Diaz.
+/* Lunzip - Decompressor for the lzip format
+   Copyright (C) 2010-2021 Antonio Diaz Diaz.
 
-    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 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.
+   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, see <http://www.gnu.org/licenses/>.
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #define _FILE_OFFSET_BITS 64
 
 #include <errno.h>
 #include <stdbool.h>
-#include <stdio.h>
-#include <string.h>
 #include <stdint.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "lzip.h"
@@ -58,8 +58,7 @@ static bool push_back_member( struct Lzip_index * const li,
   struct Member * p;
   void * tmp = resize_buffer( li->member_vector,
                ( li->members + 1 ) * sizeof li->member_vector[0] );
-  if( !tmp )
-    { add_error( li, "Not enough memory." ); li->retval = 1; return false; }
+  if( !tmp ) { add_error( li, mem_msg ); li->retval = 1; return false; }
   li->member_vector = (struct Member *)tmp;
   p = &(li->member_vector[li->members]);
   init_member( p, dp, ds, mp, ms, dict_size );
@@ -89,6 +88,19 @@ static void Li_reverse_member_vector( struct Lzip_index * const li )
   }
 
 
+static bool Li_check_header_error( struct Lzip_index * const li,
+                                   const Lzip_header header )
+  {
+  if( !Lh_verify_magic( header ) )
+    { add_error( li, bad_magic_msg ); li->retval = 2; return true; }
+  if( !Lh_verify_version( header ) )
+    { add_error( li, bad_version( Lh_version( header ) ) ); li->retval = 2;
+      return true; }
+  if( !isvalid_ds( Lh_get_dictionary_size( header ) ) )
+    { add_error( li, bad_dict_msg ); li->retval = 2; return true; }
+  return false;
+  }
+
 static void Li_set_errno_error( struct Lzip_index * const li,
                                 const char * const msg )
   {
@@ -106,9 +118,18 @@ static void Li_set_num_error( struct Lzip_index * const li,
   }
 
 
+static bool Li_read_header( struct Lzip_index * const li, const int fd,
+                            Lzip_header header, const long long pos )
+  {
+  if( seek_read( fd, header, Lh_size, pos ) != Lh_size )
+    { Li_set_errno_error( li, "Error reading member header: " ); return false; }
+  return true;
+  }
+
+
 /* If successful, push last member and set pos to member header. */
-static bool Li_skip_trailing_data( struct Lzip_index * const li,
-                                   const int fd, long long * const pos,
+static bool Li_skip_trailing_data( struct Lzip_index * const li, const int fd,
+                                   unsigned long long * const pos,
                                    const bool ignore_trailing,
                                    const bool loose_trailing )
   {
@@ -135,36 +156,40 @@ static bool Li_skip_trailing_data( struct Lzip_index * const li,
       if( buffer[i-1] <= max_msb )	/* most significant byte of member_size */
         {
         Lzip_header header;
+        const Lzip_header * header2;
         const Lzip_trailer * const trailer =
           (const Lzip_trailer *)( buffer + i - Lt_size );
         const unsigned long long member_size = Lt_get_member_size( *trailer );
         unsigned dictionary_size;
+        bool full_h2;
         if( member_size == 0 )			/* skip trailing zeros */
           { while( i > Lt_size && buffer[i-9] == 0 ) --i; continue; }
         if( member_size > ipos + i || !Lt_verify_consistency( *trailer ) )
           continue;
-        if( seek_read( fd, header, Lh_size,
-                       ipos + i - member_size ) != Lh_size )
-          { Li_set_errno_error( li, "Error reading member header: " );
-            return false; }
-        dictionary_size = Lh_get_dictionary_size( header );
-        if( !Lh_verify_magic( header ) || !Lh_verify_version( header ) ||
-            !isvalid_ds( dictionary_size ) ) continue;
-        if( Lh_verify_prefix( buffer + i, bsize - i ) )
+        if( !Li_read_header( li, fd, header, ipos + i - member_size ) )
+          return false;
+        if( !Lh_verify( header ) ) continue;
+        header2 = (const Lzip_header *)( buffer + i );
+        full_h2 = bsize - i >= Lh_size;
+        if( Lh_verify_prefix( *header2, bsize - i ) )	/* last member */
           {
-          add_error( li, "Last member in input file is truncated or corrupt." );
+          if( !full_h2 ) add_error( li, "Last member in input file is truncated." );
+          else if( !Li_check_header_error( li, *header2 ) )
+            add_error( li, "Last member in input file is truncated or corrupt." );
           li->retval = 2; return false;
           }
-        if( !loose_trailing && bsize - i >= Lh_size &&
-            Lh_verify_corrupt( buffer + i ) )
+        if( !loose_trailing && full_h2 && Lh_verify_corrupt( *header2 ) )
           { add_error( li, corrupt_mm_msg ); li->retval = 2; return false; }
         if( !ignore_trailing )
           { add_error( li, trailing_msg ); li->retval = 2; return false; }
         *pos = ipos + i - member_size;
+        dictionary_size = Lh_get_dictionary_size( header );
+        if( li->dictionary_size < dictionary_size )
+          li->dictionary_size = dictionary_size;
         return push_back_member( li, 0, Lt_get_data_size( *trailer ), *pos,
                                  member_size, dictionary_size );
         }
-    if( ipos <= 0 )
+    if( ipos == 0 )
       { Li_set_num_error( li, "Bad trailer at pos ", *pos - Lt_size );
         return false; }
     bsize = buffer_size;
@@ -180,7 +205,7 @@ bool Li_init( struct Lzip_index * const li, const int infd,
               const bool ignore_trailing, const bool loose_trailing )
   {
   Lzip_header header;
-  long long pos;
+  unsigned long long pos;
   long i;
   li->member_vector = 0;
   li->error = 0;
@@ -188,6 +213,7 @@ bool Li_init( struct Lzip_index * const li, const int infd,
   li->members = 0;
   li->error_size = 0;
   li->retval = 0;
+  li->dictionary_size = 0;
   if( li->insize < 0 )
     { Li_set_errno_error( li, "Input file is not seekable: " ); return false; }
   if( li->insize < min_member_size )
@@ -197,15 +223,8 @@ bool Li_init( struct Lzip_index * const li, const int infd,
     { add_error( li, "Input file is too long (2^63 bytes or more)." );
       li->retval = 2; return false; }
 
-  if( seek_read( infd, header, Lh_size, 0 ) != Lh_size )
-    { Li_set_errno_error( li, "Error reading member header: " ); return false; }
-  if( !Lh_verify_magic( header ) )
-    { add_error( li, bad_magic_msg ); li->retval = 2; return false; }
-  if( !Lh_verify_version( header ) )
-    { add_error( li, bad_version( Lh_version( header ) ) ); li->retval = 2;
-      return false; }
-  if( !isvalid_ds( Lh_get_dictionary_size( header ) ) )
-    { add_error( li, bad_dict_msg ); li->retval = 2; return false; }
+  if( !Li_read_header( li, infd, header, 0 ) ) return false;
+  if( Li_check_header_error( li, header ) ) return false;
 
   pos = li->insize;		/* always points to a header or to EOF */
   while( pos >= min_member_size )
@@ -216,19 +235,16 @@ bool Li_init( struct Lzip_index * const li, const int infd,
     if( seek_read( infd, trailer, Lt_size, pos - Lt_size ) != Lt_size )
       { Li_set_errno_error( li, "Error reading member trailer: " ); break; }
     member_size = Lt_get_member_size( trailer );
-    if( member_size > (unsigned long long)pos || !Lt_verify_consistency( trailer ) )
-      {
+    if( member_size > pos || !Lt_verify_consistency( trailer ) )
+      {							/* bad trailer */
       if( li->members <= 0 )
         { if( Li_skip_trailing_data( li, infd, &pos, ignore_trailing,
               loose_trailing ) ) continue; else return false; }
       Li_set_num_error( li, "Bad trailer at pos ", pos - Lt_size );
       break;
       }
-    if( seek_read( infd, header, Lh_size, pos - member_size ) != Lh_size )
-      { Li_set_errno_error( li, "Error reading member header: " ); break; }
-    dictionary_size = Lh_get_dictionary_size( header );
-    if( !Lh_verify_magic( header ) || !Lh_verify_version( header ) ||
-        !isvalid_ds( dictionary_size ) )
+    if( !Li_read_header( li, infd, header, pos - member_size ) ) break;
+    if( !Lh_verify( header ) )				/* bad header */
       {
       if( li->members <= 0 )
         { if( Li_skip_trailing_data( li, infd, &pos, ignore_trailing,
@@ -237,6 +253,9 @@ bool Li_init( struct Lzip_index * const li, const int infd,
       break;
       }
     pos -= member_size;
+    dictionary_size = Lh_get_dictionary_size( header );
+    if( li->dictionary_size < dictionary_size )
+      li->dictionary_size = dictionary_size;
     if( !push_back_member( li, 0, Lt_get_data_size( trailer ), pos,
                            member_size, dictionary_size ) )
       return false;