qmail starttls patch does not seed the random number generator

From: Felix von Leitner (felix-qmailat_private)
Date: Tue Aug 14 2001 - 17:57:36 PDT

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    openssl-0.9.6b does not allow ssl/tls connections when the random number
    has not been seeded.  This is a good idea, and it exposes that the
    starttls patch for qmail does not seed the random number generator.
    
    Here is a small patch that fixes the problem in qmail-remote for systems
    that support /dev/urandom (the same can be done for qmail-smtpd but I
    can't test it right now).  Not seeding the random number generator is a
    serious bug and it completely compromises the cryptographic privacy of
    TLS encrypted emails.
    
    Felix
    
    --- qmail-1.03/qmail-remote.c	Wed Aug 15 02:52:23 2001
    +++ qmail-1.03-diet/qmail-remote.c	Wed Aug 15 02:43:07 2001
    @@ -431,6 +431,13 @@
           SSL_set_fd(ssl,smtpfd);
     
           alarm(timeout);
    +      {
    +	int randfd=open_read("/dev/urandom");
    +	char buf[64];
    +	int len=read(randfd,buf,64);
    +	close(randfd);
    +	if (len>32) RAND_seed(buf,len);
    +      }
           r = SSL_connect(ssl); saveerrno = errno;
           alarm(0); 
           if (flagtimedout) 
    



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