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
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)
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
