Merge branch 'rs/ban-mktemp'

Rewrite the only use of "mktemp()" that is subject to TOCTOU race
and Stop using the insecure "mktemp()" function.

* rs/ban-mktemp:
  compat: remove gitmkdtemp()
  banned.h: ban mktemp(3)
  compat: remove mingw_mktemp()
  compat: use git_mkdtemp()
  wrapper: add git_mkdtemp()

Author: gitster

Makefile

@@ -1919,7 +1919,6 @@ ifdef NO_SETENV
 endif
 ifdef NO_MKDTEMP
 	COMPAT_CFLAGS += -DNO_MKDTEMP
-	COMPAT_OBJS += compat/mkdtemp.o
 endif
 ifdef MKDIR_WO_TRAILING_SLASH
 	COMPAT_CFLAGS += -DMKDIR_WO_TRAILING_SLASH

banned.h

@@ -41,4 +41,7 @@
 #undef asctime_r
 #define asctime_r(t, buf) BANNED(asctime_r)
 
+#undef mktemp
+#define mktemp(x) BANNED(mktemp)
+
 #endif /* BANNED_H */

compat/mingw-posix.h

@@ -241,9 +241,6 @@ int mingw_chdir(const char *dirname);
 int mingw_chmod(const char *filename, int mode);
 #define chmod mingw_chmod
 
-char *mingw_mktemp(char *template);
-#define mktemp mingw_mktemp
-
 char *mingw_getcwd(char *pointer, int len);
 #define getcwd mingw_getcwd
 

compat/mingw.c

@@ -1164,18 +1164,6 @@ unsigned int sleep (unsigned int seconds)
 	return 0;
 }
 
-char *mingw_mktemp(char *template)
-{
-	wchar_t wtemplate[MAX_PATH];
-	if (xutftowcs_path(wtemplate, template) < 0)
-		return NULL;
-	if (!_wmktemp(wtemplate))
-		return NULL;
-	if (xwcstoutf(template, wtemplate, strlen(template) + 1) < 0)
-		return NULL;
-	return template;
-}
-
 int mkstemp(char *template)
 {
 	return git_mkstemp_mode(template, 0600);

compat/mkdtemp.c

@@ -329,8 +329,7 @@ int gitsetenv(const char *, const char *, int);
 #endif
 
 #ifdef NO_MKDTEMP
-#define mkdtemp gitmkdtemp
-char *gitmkdtemp(char *);
+#define mkdtemp git_mkdtemp
 #endif
 
 #ifdef NO_UNSETENV

compat/posix.h

@@ -411,10 +411,6 @@ if(NOT HAVE_SETENV)
 	list(APPEND compat_SOURCES compat/setenv.c)
 endif()
 
-if(NOT HAVE_MKDTEMP)
-	list(APPEND compat_SOURCES compat/mkdtemp.c)
-endif()
-
 if(NOT HAVE_PREAD)
 	list(APPEND compat_SOURCES compat/pread.c)
 endif()

contrib/buildsystems/CMakeLists.txt

@@ -1401,7 +1401,7 @@ checkfuncs = {
   'strlcpy' : ['strlcpy.c'],
   'strtoull' : [],
   'setenv' : ['setenv.c'],
-  'mkdtemp' : ['mkdtemp.c'],
+  'mkdtemp' : [],
   'initgroups' : [],
   'strtoumax' : ['strtoumax.c', 'strtoimax.c'],
   'pread' : ['pread.c'],

meson.build

@@ -429,7 +429,11 @@ int xmkstemp(char *filename_template)
 #undef TMP_MAX
 #define TMP_MAX 16384
 
-int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
+/*
+ * Returns -1 on error, 0 if it created a directory, or an open file
+ * descriptor to the created regular file.
+ */
+static int git_mkdstemps_mode(char *pattern, int suffix_len, int mode, bool dir)
 {
 	static const char letters[] =
 		"abcdefghijklmnopqrstuvwxyz"
@@ -471,7 +475,10 @@ int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
 			v /= num_letters;
 		}
 
-		fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
+		if (dir)
+			fd = mkdir(pattern, mode);
+		else
+			fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
 		if (fd >= 0)
 			return fd;
 		/*
@@ -486,6 +493,16 @@ int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
 	return -1;
 }
 
+char *git_mkdtemp(char *pattern)
+{
+	return git_mkdstemps_mode(pattern, 0, 0700, true) ? NULL : pattern;
+}
+
+int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
+{
+	return git_mkdstemps_mode(pattern, suffix_len, mode, false);
+}
+
 int git_mkstemp_mode(char *pattern, int mode)
 {
 	/* mkstemp is just mkstemps with no suffix */

wrapper.c

@@ -37,6 +37,8 @@ int xsnprintf(char *dst, size_t max, const char *fmt, ...);
 
 int xgethostname(char *buf, size_t len);
 
+char *git_mkdtemp(char *pattern);
+
 /* set default permissions by passing mode arguments to open(2) */
 int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
 int git_mkstemp_mode(char *pattern, int mode);