QNX RTOS v4 Knowledge Base
QNX RTOS v4 Knowledge Base
| Title |
QNX Crypt fix posted for Beta |
| Ref. No. |
QNX.000009619 |
| Category(ies) |
Utilities, Configuration |
| Issue |
Is there a fix for the cracked QNX crypt() function? |
| Solution |
Yes, there is a fix for this using the standard Unix DES crypt()methods. The result is this Security Update, which has been tested and is ready for beta customers.
Here is a description of what the crypt() fix archive contains.
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QNX Operating System
Security Update
Release Notes
_________________________________________________________________
Note: To obtain technical support for any QNX product, visit the
Technical Support section in the Support area on our website
(www.qnx.com). You'll find a wide range of support options,
including our free web-based QNX Developer's Network.
_________________________________________________________________
This file contains the following sections:
Components included in this update
Installation issues
History of the problem
Source code
Components included in this update
For this product: These utilities/libs were updated:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
QNX OS v4.25 login
passwd
su
Photon v1.14 phlogin
TCP/IP Runtime v4.25 ftpd
pcnfsd
popper
pppd
rexecd
tn3270
map3270
Watcom v10.6 unix3r.lib
unix3s.lib
unixc.lib
unixg3r.lib
unixh.lib
unixl.lib
unixm.lib
unixs.lib
QNX Windows v4.24 olwm
Installation issues
_________________________________________________________________
Note: Only root users can affect security on your system - normal
users don't have read access to the /etc/shadow file.
You must be root to install the Security Update.
_________________________________________________________________
You must install the QNX Security Update archive before any other
archives. This archive decrypts the current /etc/shadow file and then
encrypts the shadow file again using the standard Unix crypt().
During installation, the install program will first back up all files
that need to be updated. The backup files will be named
filename.qcrypt.
All files that need to be updated must be present during the install
process. This avoids possible version-conflict errors. If some files
are missing during installation, the installer will make you aware of
the problem. If you run into this problem, the best solution would be
to install the affected product again from the original CD, diskset,
or archives.
_________________________________________________________________
Note: The fixes in this Security Update have been tested only with the
latest released software and contain only crypt-related changes.
_________________________________________________________________
History of the problem
In 1990, QNX qcrypt() was written using our own methods of encryption.
Although DES was available at that time, with the export restrictions
in place we would have been unable to ship our products
internationally. This simply was not an option at the time.
Recently, we heard that the QNX 4 crypt() function had been cracked.
Immediately we had a fix for this using the standard Unix DES crypt()
methods. The result is this Security Update, which has been tested and
is ready for beta customers.
Source code
The Security Update archive includes a utility (fix-shadow) that
decrypts the current /etc/shadow file and then encrypts the shadow
file again using the standard Unix crypt().
Under /updates/qnx42/Beta/Security, we've posted the source code for
the files that were used to create the fix-shadow utility:
main.c
Main function
quncrypt.c
Decrypt function
crypt.c
Standard Unix crypt() function
We used this cc command line to build the fix-shadow executable:
cc -l main.c quncrypt.c crypt.c -o fix-shadow
_________________________________________________________________
Caution: The source code used to fix the security problem was
published *for your information*. You don't need to actually build and
run the fix-shadow utility, because installing this Security Update
automatically produces a secure /etc/shadow file for you.
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