Merge lp:~yavor-nikolov/pbzip2/bug-807536-excessive-output-permissions into lp:pbzip2/1.1

[Yavor Nikolov]

Merged fix for bug #807536 (excessive output permissions while compress/decompress is in progress)

Fixed excessive output permissions while compress/decompress is in progress (bug #807536)

[lp:~yavor-nikolov/pbzip2/bug-807536-excessive-output-permissions]

24. By Yavor Nikolov on 2011-07-13

Fixed excessive output permissions during compress/decompress in case of output file already existed (additional fix for bug #807536).

=== modified file 'ChangeLog'
--- ChangeLog	2011-07-11 18:20:53 +0000
+++ ChangeLog	2011-07-13 22:04:28 +0000
@@ -1,4 +1,6 @@
 Changes in 1.1.5 (NOT RELEASED YET)
+- Fixed excessive output permissions while compress/decompress
+  is in progress (bug #807536)
 Changes in 1.1.4 (Apr 22, 2011)
 - Fixed hang on decompress with --ignore-trailing-garbage=1 when
   producer is interrupted on trailing garbage (bug #762464)

=== modified file 'pbzip2.cpp'
--- pbzip2.cpp	2011-07-11 18:20:53 +0000
+++ pbzip2.cpp	2011-07-13 22:04:28 +0000
@@ -194,6 +194,9 @@
  *                    - Print trailing garbage errors even when in quiet mode (bug #743635)
  *                    - Fixed hang on decompress with --ignore-trailing-garbage=1 when
  *                      producer is interrupted on trailing garbage (bug #762464)
+ *                    - Fixed excessive output permissions while compress/decompress
+ *                      is in progress (bug #807536)
+ *
  *
  *
  *  Specials thanks for suggestions and testing:  Phillippe Welsh,
@@ -566,6 +569,53 @@
 	return (count - bytesRemaining);
 }
 
+/*
+ * Open output file with least required privileges
+ */
+int safe_open_output(const char *path)
+{
+	return open(path, O_WRONLY | O_CREAT | O_EXCL | O_BINARY, FILE_MODE);
+}
+
+/*
+ * Based on bzip2.c code
+ */
+FILE *safe_fopen_output(const char *path, const char *mode)
+{
+	int fh = safe_open_output(path);
+	if (fh == -1)
+	{
+		return NULL;
+	}
+	
+	FILE *fp = fdopen(fh, mode);
+	if (fp == NULL)
+	{
+		close(fh);
+	}
+
+	return fp;
+}
+
+/**
+ * Check if a given file exists.
+ *
+ * @return true if file exists and false if it doesn't
+ */
+bool check_file_exists( const char * filename )
+{
+	int hOutfile = open( filename, O_RDONLY | O_BINARY );
+	
+	if ( hOutfile == -1 )
+	{
+		return false;
+	}
+	else
+	{
+		close( hOutfile );
+		return true;
+	}
+}
 
 /*
  *********************************************************
@@ -1658,7 +1708,7 @@
 	// write to file instead of stdout
 	if (OutputStdOut == 0)
 	{
-		hOutfile = open(OutFilename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, FILE_MODE);
+		hOutfile = safe_open_output(OutFilename);
 		// check to see if file creation was successful
 		if (hOutfile == -1)
 		{
@@ -1913,7 +1963,7 @@
 	// write to file instead of stdout
 	if (OutputStdOut == 0)
 	{
-		hOutfile = open(OutFilename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, FILE_MODE);
+		hOutfile = safe_open_output(OutFilename);
 		// check to see if file creation was successful
 		if (hOutfile == -1)
 		{
@@ -2156,7 +2206,7 @@
 	// see if we are outputting to stdout
 	if (OutputStdOut == 0)
 	{
-		stream = fopen(OutFilename, "wb");
+		stream = safe_fopen_output(OutFilename, "wb");
 		if (stream == NULL)
 		{
 			handle_error(EF_NOQUIT, -1,
@@ -4040,19 +4090,19 @@
 		}
 
 		// check to see if output file exists
-		if ((force != 1) && (OutputStdOut == 0))
-		{
-			hOutfile = open(outFilename.c_str(), O_RDONLY | O_BINARY);
-			// check to see if file exists before processing
-			if (hOutfile != -1)
+		if ((OutputStdOut == 0) && check_file_exists(outFilename.c_str()))
+		{	
+			if (force != 1)
 			{
 				fprintf(stderr, "pbzip2: *ERROR: Output file [%s] already exists!  Use -f to overwrite...\n", outFilename.c_str());
 				fprintf(stderr, "-------------------------------------------\n");
 				errLevel = 1;
-				close(hOutfile);
-				errLevel = 1;
 				continue;
 			}
+			else
+			{
+				remove(outFilename.c_str());
+			}
 		}
 
 		if (readEntireFile == 1)
@@ -4125,7 +4175,7 @@
 				// write to file instead of stdout
 				if (OutputStdOut == 0)
 				{
-					hOutfile = open(outFilename.c_str(), O_RDWR | O_CREAT | O_TRUNC | O_BINARY, FILE_MODE);
+					hOutfile = safe_open_output(outFilename.c_str());
 					// check to see if file creation was successful
 					if (hOutfile == -1)
 					{

=== modified file 'pbzip2.h'
--- pbzip2.h	2011-02-13 15:00:47 +0000
+++ pbzip2.h	2011-07-13 22:04:28 +0000
@@ -16,11 +16,11 @@
 #include <string>
 #include <cctype>
 
+#define	FILE_MODE	(S_IRUSR | S_IWUSR )
+
 #ifndef WIN32
-#define	FILE_MODE	(S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)
 #define OFF_T		off_t
 #else
-#define	FILE_MODE	(S_IRUSR | S_IWUSR )
 #define OFF_T		__int64
 #endif