1 files changed, 99 insertions, 0 deletions
diff --git a/common/mkdtemp.c b/common/mkdtemp.c
new file mode 100644
index 000000000..9b76f8957
--- /dev/null
+++ b/common/mkdtemp.c
@@ -0,0 +1,99 @@
+/* mkdtemp.c - libc replacement function
+ * Copyright (C) 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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.
+ *
+ * GnuPG 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+/* This is a replacement function for mkdtemp in case the platform
+   we're building on (like mine!) doesn't have it. */
+
+#include <config.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <gcrypt.h>
+
+#ifdef MKDIR_TAKES_ONE_ARG
+# undef mkdir
+# define mkdir(a,b) mkdir(a)
+#endif
+
+char *mkdtemp(char *template)
+{
+  int attempts,idx,count=0;
+  byte *ch;
+
+  idx=strlen(template);
+
+  /* Walk backwards to count all the Xes */
+  while(idx>0 && template[idx-1]=='X')
+    {
+      count++;
+      idx--;
+    }
+
+  if(count==0)
+    {
+      errno=EINVAL;
+      return NULL;
+    }
+
+  ch=&template[idx];
+
+  /* Try 4 times to make the temp directory */
+  for(attempts=0;attempts<4;attempts++)
+    {
+      int remaining=count;
+      char *marker=ch;
+      byte *randombits;
+
+      idx=0;
+
+      /* Using really random bits is probably overkill here.  The
+	 worst thing that can happen with a directory name collision
+	 is that the function will return an error. */
+
+      randombits = gcry_random_bytes (4*remaining, GCRY_WEAK_RANDOM);
+
+      while(remaining>1)
+	{
+	  sprintf(marker,"%02X",randombits[idx++]);
+	  marker+=2;
+	  remaining-=2;
+	}
+
+      /* Any leftover Xes?  get_random_bits rounds up to full bytes,
+         so this is safe. */
+      if(remaining>0)
+	sprintf(marker,"%X",randombits[idx]&0xF);
+
+      gcry_free (randombits);
+
+      if(mkdir(template,0700)==0)
+	break;
+    }
+
+  if(attempts==4)
+    return NULL; /* keeps the errno from mkdir, whatever it is */
+
+  return template;
+}
+
+