glibc has a pretty nice function called crypt_r(3), which is nothing
more than crypt(3), but thread-safe. It accomplishes this by introducing
a 'struct crypt_data' structure that contains a buffer that is large
enough to hold the resulting string.
Let's go ahead and also add this function. It would be a shame if a
useful function like this wouldn't be usable in multithreaded apps.
Refactor crypt.c and all of the backends to no longer declare static
arrays, but write their output in a provided buffer.
There is no need to do any buffer length computation here, as we'll just
need to ensure that 'struct crypt_data' is large enough, which it is.
_PASSWORD_LEN is defined to 128 bytes, but in this case I'm picking 256,
as this is going to be part of the actual ABI.
Differential Revision: https://reviews.freebsd.org/D7306
since they don't have an easily recognizable signature, was if they
were the default. This commit rewrites crypt_set_format(3) etc to
address this:
- Use a pointer instead of an index to identify the default format.
This pointer is initialized at compile time to point to the first
first element in the list of supported formats, eliminating the
need for crypt_setdefault(). Using a pointer also simplifies
iterating through the list.
- Associate DES with the magic string "_", which takes care of the
Extended DES format.
- Finally, as a special case, if the salt does not match any known
magic string but matches ^[./0-9A-Za-z]{13}$, it is assumed to be a
DES password and is passed on to crypt_des().
MFC after: 1 week
hashing scheme used in Microsoft's NT machines. IT IS NOT SECURE!
DON'T USE IT! This is for the use of competent sysadmins only!
Submitted by: Michael Bretterklieber
gratuitous difference between us and our sister project.
This was given to me _ages_ ago. May apologies to Paul for the length
of time its taken me to commit.
Obtained from: Niels Provos <provos@physnet.uni-hamburg.de>/OpenBSD
Submitted by: Paul Herman <pherman@frenchfries.net>
so I am backing it out for now. The problem is that some random program
calling crypt() could be passing a DES salt and the crypt(3) library
would encrypt it in md5 mode and there would be a password mismatch as a
result. I wrote a validater function for the DES code to verify that
a salt is valid for DES, but I realized there were too many strange things
to go wrong. passwd(1), pw(8) etc still generate md5 passwords by default
for /etc/master.passwd, so this is almost academic. It is a big deal for
things that have their own crypt(3)-ed password strings (.htaccess,
etc etc). Those are the things I do not want to break.
My DES salt recognizer basically checked if the salt was either 2 or
13 characters long, or began with '_' (_PASSWORD_EFMT1). I think it
would have worked but I have seen way too much crypt() mishandling
in the past.
one-way hash functions for authentication purposes. There is no more
"set the libcrypt->libXXXcrypt" nightmare.
- Undo the libmd.so hack, use -D to hide the md5c.c internals.
- Remove the symlink hacks in release/Makefile
- the algorthm is set by set_crypt_format() as before. If this is
not called, it tries to heuristically figure out the hash format, and
if all else fails, it uses the optional auth.conf entry to chose the
overall default hash.
- Since source has non-hidden crypto in it there may be some issues with
having the source it in some countries, so preserve the "secure/*"
division. You can still build a des-free libcrypt library if you want
to badly enough. This should not be a problem in the US or exporting
from the US as freebsd.org had notified BXA some time ago. That makes
this stuff re-exportable by anyone.
- For consistancy, the default in absence of any other clues is md5. This
is to try and minimize POLA across buildworld where folk may suddenly
be activating des-crypt()-hash support. Since the des hash may not
always be present, it seemed sensible to make the stronger md5 algorithm
the default.
All things being equal, no functionality is lost.
Reviewed-by: jkh
(flame-proof suit on)
for crypt(3) by now. In any case:
Add crypt_set_format(3) + documentation to -lcrypt.
Add login_setcryptfmt(3) + documentation to -lutil.
Support for switching crypt formats in passwd(8).
Support for switching crypt formats in pw(8).
The simple synopsis is:
edit login.conf; add a passwd_format field set to "des" or "md5"; go nuts :)
Reviewed by: peter
Secure Hashing Algorithm - 1 (SHA-1), along with the further
refinement of what $x$salt$hash means. With this new crypt the
following are all acceptable:
$1$
$MD5$
$SHA1$
Note: $2$ is used by OpenBSD's Blowfish, which I considered adding
as $BF$, but there is no actual need for it with SHA-1. However,
somebody wishing to add OpenBSD password support could easilly add
it in now.
There is also a malloc_crypt() available in the library now, which
behaves exactly the same as crypt(), but it uses a malloced buffer
instead of a static buffer. However, this is not standard so will
likely not be used much (at all).
Also, for those interested I did a brief speed test Pentium 166/MMX,
which shows the DES crypt to do approximately 2640 crypts a CPU second,
MD5 to do about 62 crypts a CPU second and SHA1 to do about 18 crypts
a CPU second.
Reviewed by: Mark Murray
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
This effectively changes the non-DES password algoritm.
If you have the "securedist" installed you will have no problems with this.
(Though you might want to consider using this password-encryption instead
of the DES-based if your system is likely to be hacked)
If you are running a -current system without the "securedist" installed:
YOU WILL NEED TO CHANGE ALL PASSWORDS !! There is no backwards mode.
Suggested procedure is:
Update your sources
cd /usr/src/lib/libcrypt
make clean
make all
make install
passwd root
<set roots new password>
change password for any other users on the system.
This algorithm is expected to be much better than the traditional DES-
based algorithm. It uses the MD5 algorithm at what it is best at, as
opposed to the DES algorithm at something it isn't good at at all. The
algorithm is designed such that it should very hard to shortcut the
calculations needed to build a dictionary, and to make partial knowledge
(Hmm, his password starts with a 'P'...) useless. Of course if somebody
breaks the MD5 algorithm this looses too.
The salt is 48 bits (8 char @ base64).
The encrypted password is 128 bits.
And I am positively delighted to say that it takes 34 msec to crypt() a
password on a Pentium/60Mhz, so building a dictionary is not really an
option for hackers at the moment.
