[19183] in bugtraq

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Bad PRNGs revisted in FreSSH

daemon@ATHENA.MIT.EDU (Charles M. Hannum)
Tue Feb 13 16:09:18 2001

Message-ID:  <200102130310.f1D3ATa16591@trinity.ihack.net>
Date:         Tue, 13 Feb 2001 03:10:29 GMT
Reply-To: "Charles M. Hannum" <root@IHACK.NET>
From: "Charles M. Hannum" <root@IHACK.NET>
To: BUGTRAQ@SECURITYFOCUS.COM

The newly announced FreSSH, when there is no /dev/urandom available,
uses a `fallback' to seed its PRNG that consists of:

                        int numfs, whichfs = 0;
                        struct statfs *mntbuf;
                        numfs = getmntinfo(&mntbuf, MNT_NOWAIT);
                        while (whichfs < numfs) {
                                ssh_rand_feed((void *) mntbuf,
                                    sizeof(struct statfs));
                                memset(mntbuf, 0, sizeof(struct statfs));
                                mntbuf++;
                                whichfs++;
                        }

I don't think I need to tell people on this list why that's absolutely
horrible; I'm just pointing out that code is still released today with
crap like this.  I would have thought we'd learned this lesson years
ago with the AFS, krb4, Netscape, et al vulnerabilities.

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