Re: make-string uninitialized memory eposure considered harmful

[Mikael Djurfeldt]

Egil Moeller <address@hidden> writes:

> one might think of a situation when one would like to be able to
> create a string (or other object?) that, when garbage-collected, was
> guaranteed to be overwritten with 0's. Is this doable?

(define-module (utils self-destruct)
  #:export (make-self-destructing-string))

(define guard-string (make-guardian))

(define (make-self-destructing-string k)
  (let ((s (make-string k)))
    (guard-string s)
    s))

(define (destroy-strings)
  (cond ((guard-string)
         =>
         (lambda (s)
           (string-fill! s #\nul)
           (destroy-strings)))))

(add-hook! after-gc-hook destroy-strings)

M