Another utility function, to free a string containing sensitive data.

[originally from svn r9319]

misc.c

@@ -200,6 +200,14 @@ char *dupcat(const char *s1, ...)
     return p;
 }
 
+void burnstr(char *string)             /* sfree(str), only clear it first */
+{
+    if (string) {
+        memset(string, 0, strlen(string));
+        sfree(string);
+    }
+}
+
 /*
  * Do an sprintf(), but into a custom-allocated buffer.
  * 

misc.h

@@ -28,6 +28,7 @@ char *dupstr(const char *s);
 char *dupcat(const char *s1, ...);
 char *dupprintf(const char *fmt, ...);
 char *dupvprintf(const char *fmt, va_list ap);
+void burnstr(char *string);
 
 char *fgetline(FILE *fp);