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d0d71d818c
At a basic level, remove assumptions about the underlying algorithm (such as output block size and reseeding requirements) from the algorithm-independent logic in randomdev.c. Chacha20 does not have many of the restrictions that AES-ICM does as a PRF (Pseudo-Random Function), because it has a cipher block size of 512 bits. The motivation is that by generalizing the API, Chacha is not penalized by the limitations of AES. In READ_RANDOM_UIO, first attempt to NOWAIT allocate a large enough buffer for the entire user request, or the maximal input we'll accept between signal checking, whichever is smaller. The idea is that the implementation of any randomdev algorithm is then free to divide up large requests in whatever fashion it sees fit. As part of this, two responsibilities from the "algorithm-generic" randomdev code are pushed down into the Fortuna ra_read implementation (and any other future or out-of-tree ra_read implementations): 1. If an algorithm needs to rekey every N bytes, it is responsible for handling that in ra_read(). (I.e., Fortuna's 1MB rekey interval for AES block generation.) 2. If an algorithm uses a block cipher that doesn't tolerate partial-block requests (again, e.g., AES), it is also responsible for handling that in ra_read(). Several APIs are changed from u_int buffer length to the more canonical size_t. Several APIs are changed from taking a blockcount to a bytecount, to permit PRFs like Chacha20 to directly generate quantities of output that are not multiples of RANDOM_BLOCKSIZE (AES block size). The Fortuna algorithm is changed to NOT rekey every 1MiB when in Chacha20 mode (kern.random.use_chacha20_cipher="1"). This is explicitly supported by the math in FS&K §9.4 (Ferguson, Schneier, and Kohno; "Cryptography Engineering"), as well as by their conclusion: "If we had a block cipher with a 256-bit [or greater] block size, then the collisions would not have been an issue at all." For now, continue to break up reads into PAGE_SIZE chunks, as they were before. So, no functional change, mostly. Reviewed by: markm Approved by: secteam(delphij) Differential Revision: https://reviews.freebsd.org/D20312 |
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| etc | ||
| freebsd_test_suite | ||
| sys | ||
| Kyuafile | ||
| Makefile | ||
| Makefile.depend | ||
| Makefile.inc0 | ||
| README | ||
src/tests: The FreeBSD test suite
=================================
To run the FreeBSD test suite:
(1) Make sure that kyua is installed:
pkg install kyua
(2) To run the tests:
kyua test -k /usr/tests/Kyuafile
(3) To see the test results:
kyua report
For further information on using the test suite, read tests(7):
man tests
Description of FreeBSD test suite
=================================
The build of the test suite is organized in the following manner:
* The build of all test artifacts is protected by the MK_TESTS knob.
The user can disable these with the WITHOUT_TESTS setting in
src.conf(5).
* The goal for /usr/tests/ (the installed test programs) is to follow
the same hierarchy as /usr/src/ wherever possible, which in turn drives
several of the design decisions described below. This simplifies the
discoverability of tests. We want a mapping such as:
/usr/src/bin/cp/ -> /usr/tests/bin/cp/
/usr/src/lib/libc/ -> /usr/tests/lib/libc/
/usr/src/usr.bin/cut/ -> /usr/tests/usr.bin/cut/
... and many more ...
* Test programs for specific utilities and libraries are located next
to the source code of such programs. For example, the tests for the
src/lib/libcrypt/ library live in src/lib/libcrypt/tests/. The tests/
subdirectory is optional and should, in general, be avoided.
* The src/tests/ hierarchy (this directory) provides generic test
infrastructure and glue code to join all test programs together into
a single test suite definition.
* The src/tests/ hierarchy also includes cross-functional test programs:
i.e. test programs that cover more than a single utility or library
and thus don't fit anywhere else in the tree. Consider this to follow
the same rationale as src/share/man/: this directory contains generic
manual pages while the manual pages that are specific to individual
tools or libraries live next to the source code.
In order to keep the src/tests/ hierarchy decoupled from the actual test
programs being installed --which is a worthy goal because it simplifies
the addition of new test programs and simplifies the maintenance of the
tree-- the top-level Kyuafile does not know which subdirectories may
exist upfront. Instead, such Kyuafile automatically detects, at
run-time, which */Kyuafile files exist and uses those directly.
Similarly, every directory in src/ that wants to install a Kyuafile to
just recurse into other subdirectories reuses this Kyuafile with
auto-discovery features. As an example, take a look at src/lib/tests/
whose sole purpose is to install a Kyuafile into /usr/tests/lib/.
The goal in this specific case is for /usr/tests/lib/ to be generated
entirely from src/lib/.
--
$FreeBSD$