1 files changed, 72 insertions, 0 deletions
diff --git a/g10/mkdtemp.c b/g10/mkdtemp.c
new file mode 100644
index 000000000..6a159c02b
--- /dev/null
+++ b/g10/mkdtemp.c
@@ -0,0 +1,72 @@
+/* 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 "types.h"
+#include "cipher.h"
+
+char *mkdtemp(char *template)
+{
+  int attempts,index,count=0;
+  byte *ch;
+
+  index=strlen(template);
+  ch=&template[index-1];
+
+  /* Walk backwards to count all the Xes */
+  while(*ch=='X' && count<index)
+    {
+      count++;
+      ch--;
+    }
+
+  ch++;
+
+  if(count==0)
+    {
+      errno=EINVAL;
+      return NULL;
+    }
+
+  /* Try 4 times to make the temp directory */
+  for(attempts=0;attempts<4;attempts++)
+    {
+      int index=0,remaining=count;
+      char *marker=ch;
+      byte *randombits;
+
+      /* 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=get_random_bits(4*remaining,0,0);
+
+      while(remaining>1)
+	{
+	  sprintf(marker,"%02X",randombits[index++]);
+	  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[index]&0xF);
+
+      m_free(randombits);
+
+      if(mkdir(template,0700)==0)
+	break;
+    }
+
+  if(attempts==4)
+    return NULL; /* keeps the errno from mkdir, whatever it is */
+
+  return template;
+}