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2025-09-08random: Allow pure entropy sources to provide a min-entropy estimateMark Johnston
The current implementation of the NIST health tests assumes a min-entropy estimate of one bit per sample, which is quite conservative. For so-called "pure" sources (e.g., virtio-random, TPM) it might be nice to support larger estimates so that the tests catch failed devices more quickly. Thus: - let each pure random source provide an estimate, so that downstreams or driver implementors can override defaults if they want to; - increase the default estimate for pure sources; - for pure sources initialize the state machine at source registration time. Reviewed by: cem MFC after: 2 weeks Sponsored by: Stormshield Sponsored by: Klara, Inc. Differential Revision: https://reviews.freebsd.org/D52232
2025-09-08random: Make the entropy source registration interface more uniformMark Johnston
Most pure sources work under a "pull" model wherein a dedicated thread polls the source at regular intervals (every 100ms). A couple of sources, however, will instead call random_harvest_direct() to provide entropy samples. Such sources were not calling random_source_register() and thus weren't in the global random source list. Modify "push" sources to use random_source_register() like other sources do. Such sources omit an implementation of rs_read and are thus skipped by the above-mentioned thread. This makes it easier to allow pure sources to provide a min-entropy estimate in a uniform way. Reviewed by: cem MFC after: 2 weeks Sponsored by: Stormshield Sponsored by: Klara, Inc. Differential Revision: https://reviews.freebsd.org/D52229
2025-08-19random: Make random_source definitions constMark Johnston
We can do so trivially, so make these tables read-only. No functional change intended. Reviewed by: cem, emaste MFC after: 2 weeks Sponsored by: Stormshield Sponsored by: Klara, Inc. Differential Revision: https://reviews.freebsd.org/D52003
2023-08-16sys: Remove $FreeBSD$: two-line .h patternWarner Losh
Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/
2019-12-26random(4): Simplify RANDOM_LOADABLEConrad Meyer
Simplify RANDOM_LOADABLE by removing the ability to unload a LOADABLE random(4) implementation. This allows one-time random module selection at boot, by loader(8). Swapping modules on the fly doesn't seem especially useful. This removes the need to hold a lock over the sleepable module calls read_random and read_random_uio. init/deinit have been pulled out of random_algorithm entirely. Algorithms can run their own sysinits to initialize; deinit is removed entirely, as algorithms can not be unloaded. Algorithms should initialize at SI_SUB_RANDOM:SI_ORDER_SECOND. In LOADABLE systems, algorithms install a pointer to their local random_algorithm context in p_random_alg_context at that time. Go ahead and const'ify random_algorithm objects; there is no need to mutate them at runtime. LOADABLE kernel NULL checks are removed from random_harvestq by ordering random_harvestq initialization at SI_SUB_RANDOM:SI_ORDER_THIRD, after algorithm init. Prior to random_harvestq init, hc_harvest_mask is zero and no events are forwarded to algorithms; after random_harvestq init, the relevant pointers will already have been installed. Remove the bulk of random_infra shim wrappers and instead expose the bare function pointers in sys/random.h. In LOADABLE systems, read_random(9) et al are just thin shim macros around invoking the associated function pointer. We do not provide a registration system but instead expect LOADABLE modules to register themselves at SI_SUB_RANDOM:SI_ORDER_SECOND. An example is provided in randomdev.c, as used in the random_fortuna.ko module. Approved by: csprng(markm) Discussed with: gordon Differential Revision: https://reviews.freebsd.org/D22512 Notes: svn path=/head/; revision=356096
2019-11-22random(4): De-export random_sources listConrad Meyer
The internal datastructures do not need to be visible outside of random_harvestq, and this helps ensure they are not misused. No functional change. Approved by: csprng(delphij, markm) Differential Revision: https://reviews.freebsd.org/D22485 Notes: svn path=/head/; revision=355022
2019-11-22random(4): Remove unused definitionsConrad Meyer
Approved by: csprng(gordon, markm) Differential Revision: https://reviews.freebsd.org/D22481 Notes: svn path=/head/; revision=355017
2019-06-17random(4): Generalize algorithm-independent APIsConrad Meyer
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 Notes: svn path=/head/; revision=349138
2019-04-18random(4): Restore availability tradeoff prior to r346250Conrad Meyer
As discussed in that commit message, it is a dangerous default. But the safe default causes enough pain on a variety of platforms that for now, restore the prior default. Some of this is self-induced pain we should/could do better about; for example, programmatic CI systems and VM managers should introduce entropy from the host for individual VM instances. This is considered a future work item. On modern x86 and Power9 systems, this may be wholly unnecessary after D19928 lands (even in the non-ideal case where early /boot/entropy is unavailable), because they have fast hardware random sources available early in boot. But D19928 is not yet landed and we have a host of architectures which do not provide fast random sources. This change adds several tunables and diagnostic sysctls, documented thoroughly in UPDATING and sys/dev/random/random_infra.c. PR: 230875 (reopens) Reported by: adrian, jhb, imp, and probably others Reviewed by: delphij, imp (earlier version), markm (earlier version) Discussed with: adrian Approved by: secteam(delphij) Relnotes: yeah Security: related Differential Revision: https://reviews.freebsd.org/D19944 Notes: svn path=/head/; revision=346358
2019-04-16random(4): Add is_random_seeded(9) KPIConrad Meyer
The imagined use is for early boot consumers of random to be able to make decisions based on whether random is available yet or not. One such consumer seems to be __stack_chk_init(), which runs immediately after random is initialized. A follow-up patch will attempt to address that. Reported by: many Reviewed by: delphij (except man page) Approved by: secteam(delphij) Differential Revision: https://reviews.freebsd.org/D19926 Notes: svn path=/head/; revision=346282
2019-04-15random(4): Block read_random(9) on initial seedingConrad Meyer
read_random() is/was used, mostly without error checking, in a lot of very sensitive places in the kernel -- including seeding the widely used arc4random(9). Most uses, especially arc4random(9), should block until the device is seeded rather than proceeding with a bogus or empty seed. I did not spy any obvious kernel consumers where blocking would be inappropriate (in the sense that lack of entropy would be ok -- I did not investigate locking angle thoroughly). In many instances, arc4random_buf(9) or that family of APIs would be more appropriate anyway; that work was done in r345865. A minor cleanup was made to the implementation of the READ_RANDOM function: instead of using a variable-length array on the stack to temporarily store all full random blocks sufficient to satisfy the requested 'len', only store a single block on the stack. This has some benefit in terms of reducing stack usage, reducing memcpy overhead and reducing devrandom output leakage via the stack. Additionally, the stack block is now safely zeroed if it was used. One caveat of this change is that the kern.arandom sysctl no longer returns zero bytes immediately if the random device is not seeded. This means that FreeBSD-specific userspace applications which attempted to handle an unseeded random device may be broken by this change. If such behavior is needed, it can be replaced by the more portable getrandom(2) GRND_NONBLOCK option. On any typical FreeBSD system, entropy is persisted on read/write media and used to seed the random device very early in boot, and blocking is never a problem. This change primarily impacts the behavior of /dev/random on embedded systems with read-only media that do not configure "nodevice random". We toggle the default from 'charge on blindly with no entropy' to 'block indefinitely.' This default is safer, but may cause frustration. Embedded system designers using FreeBSD have several options. The most obvious is to plan to have a small writable NVRAM or NAND to persist entropy, like larger systems. Early entropy can be fed from any loader, or by writing directly to /dev/random during boot. Some embedded SoCs now provide a fast hardware entropy source; this would also work for quickly seeding Fortuna. A 3rd option would be creating an embedded-specific, more simplistic random module, like that designed by DJB in [1] (this design still requires a small rewritable media for forward secrecy). Finally, the least preferred option might be "nodevice random", although I plan to remove this in a subsequent revision. To help developers emulate the behavior of these embedded systems on ordinary workstations, the tunable kern.random.block_seeded_status was added. When set to 1, it blocks the random device. I attempted to document this change in random.4 and random.9 and ran into a bunch of out-of-date or irrelevant or inaccurate content and ended up rototilling those documents more than I intended to. Sorry. I think they're in a better state now. PR: 230875 Reviewed by: delphij, markm (earlier version) Approved by: secteam(delphij), devrandom(markm) Relnotes: yes Differential Revision: https://reviews.freebsd.org/D19744 Notes: svn path=/head/; revision=346250
2015-08-17Add DEV_RANDOM pseudo-option and use it to "include out" random(4)Mark Murray
if desired. Retire randomdev_none.c and introduce random_infra.c for resident infrastructure. Completely stub out random(4) calls in the "without DEV_RANDOM" case. Add RANDOM_LOADABLE option to allow loadable Yarrow/Fortuna/LocallyWritten algorithm. Add a skeleton "other" algorithm framework for folks to add their own processing code. NIST, anyone? Retire the RANDOM_DUMMY option. Build modules for Yarrow, Fortuna and "other". Use atomics for the live entropy rate-tracking. Convert ints to bools for the 'seeded' logic. Move _write() function from the algorithm-specific areas to randomdev.c Get rid of reseed() function - it is unused. Tidy up the opt_*.h includes. Update documentation for random(4) modules. Fix test program (reviewers, please leave this). Differential Revision: https://reviews.freebsd.org/D3354 Reviewed by: wblock,delphij,jmg,bjk Approved by: so (/dev/random blanket) Notes: svn path=/head/; revision=286839
2015-07-12* Address review (and add a bit myself).Mark Murray
- Tweek man page. - Remove all mention of RANDOM_FORTUNA. If the system owner wants YARROW or DUMMY, they ask for it, otherwise they get FORTUNA. - Tidy up headers a bit. - Tidy up declarations a bit. - Make static in a couple of places where needed. - Move Yarrow/Fortuna SYSINIT/SYSUNINIT to randomdev.c, moving us towards a single file where the algorithm context is used. - Get rid of random_*_process_buffer() functions. They were only used in one place each, and are better subsumed into those places. - Remove *_post_read() functions as they are stubs everywhere. - Assert against buffer size illegalities. - Clean up some silly code in the randomdev_read() routine. - Make the harvesting more consistent. - Make some requested argument name changes. - Tidy up and clarify a few comments. - Make some requested comment changes. - Make some requested macro changes. * NOTE: the thing calling itself a 'unit test' is not yet a proper unit test, but it helps me ensure things work. It may be a proper unit test at some time in the future, but for now please don't make any assumptions or hold any expectations. Differential Revision: https://reviews.freebsd.org/D2025 Approved by: so (/dev/random blanket) Notes: svn path=/head/; revision=285422
2015-06-30Huge cleanup of random(4) code.Mark Murray
* GENERAL - Update copyright. - Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set neither to ON, which means we want Fortuna - If there is no 'device random' in the kernel, there will be NO random(4) device in the kernel, and the KERN_ARND sysctl will return nothing. With RANDOM_DUMMY there will be a random(4) that always blocks. - Repair kern.arandom (KERN_ARND sysctl). The old version went through arc4random(9) and was a bit weird. - Adjust arc4random stirring a bit - the existing code looks a little suspect. - Fix the nasty pre- and post-read overloading by providing explictit functions to do these tasks. - Redo read_random(9) so as to duplicate random(4)'s read internals. This makes it a first-class citizen rather than a hack. - Move stuff out of locked regions when it does not need to be there. - Trim RANDOM_DEBUG printfs. Some are excess to requirement, some behind boot verbose. - Use SYSINIT to sequence the startup. - Fix init/deinit sysctl stuff. - Make relevant sysctls also tunables. - Add different harvesting "styles" to allow for different requirements (direct, queue, fast). - Add harvesting of FFS atime events. This needs to be checked for weighing down the FS code. - Add harvesting of slab allocator events. This needs to be checked for weighing down the allocator code. - Fix the random(9) manpage. - Loadable modules are not present for now. These will be re-engineered when the dust settles. - Use macros for locks. - Fix comments. * src/share/man/... - Update the man pages. * src/etc/... - The startup/shutdown work is done in D2924. * src/UPDATING - Add UPDATING announcement. * src/sys/dev/random/build.sh - Add copyright. - Add libz for unit tests. * src/sys/dev/random/dummy.c - Remove; no longer needed. Functionality incorporated into randomdev.*. * live_entropy_sources.c live_entropy_sources.h - Remove; content moved. - move content to randomdev.[ch] and optimise. * src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h - Remove; plugability is no longer used. Compile-time algorithm selection is the way to go. * src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h - Add early (re)boot-time randomness caching. * src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h - Remove; no longer needed. * src/sys/dev/random/uint128.h - Provide a fake uint128_t; if a real one ever arrived, we can use that instead. All that is needed here is N=0, N++, N==0, and some localised trickery is used to manufacture a 128-bit 0ULLL. * src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h - Improve unit tests; previously the testing human needed clairvoyance; now the test will do a basic check of compressibility. Clairvoyant talent is still a good idea. - This is still a long way off a proper unit test. * src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h - Improve messy union to just uint128_t. - Remove unneeded 'static struct fortuna_start_cache'. - Tighten up up arithmetic. - Provide a method to allow eternal junk to be introduced; harden it against blatant by compress/hashing. - Assert that locks are held correctly. - Fix the nasty pre- and post-read overloading by providing explictit functions to do these tasks. - Turn into self-sufficient module (no longer requires randomdev_soft.[ch]) * src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h - Improve messy union to just uint128_t. - Remove unneeded 'staic struct start_cache'. - Tighten up up arithmetic. - Provide a method to allow eternal junk to be introduced; harden it against blatant by compress/hashing. - Assert that locks are held correctly. - Fix the nasty pre- and post-read overloading by providing explictit functions to do these tasks. - Turn into self-sufficient module (no longer requires randomdev_soft.[ch]) - Fix some magic numbers elsewhere used as FAST and SLOW. Differential Revision: https://reviews.freebsd.org/D2025 Reviewed by: vsevolod,delphij,rwatson,trasz,jmg Approved by: so (delphij) Notes: svn path=/head/; revision=284959
2015-02-17When the new random adaptor code was brought it in r273872, a call toJohn-Mark Gurney
randomdev_init_reader to change read_random over to the newly installed adaptor was missed. This means both read_random and arc4random (seeded from read_random) were not returning very random data. This also effects userland arc4random as it is seeded from kernel arc4random. The random devices are uneffected and have returned good randomness since the change. All keys generated with a kernel of r273872 must be regenerated with a kernel with this patch. Keys generated may be predictable. Remove the warning as log is too early to print anything, and it would always get printed due to early use of arc4random... Reviewed by: delphij, markm Approved by: so (delphij) Notes: svn path=/head/; revision=278907
2014-10-30This is the much-discussed major upgrade to the random(4) device, known to ↵Mark Murray
you all as /dev/random. This code has had an extensive rewrite and a good series of reviews, both by the author and other parties. This means a lot of code has been simplified. Pluggable structures for high-rate entropy generators are available, and it is most definitely not the case that /dev/random can be driven by only a hardware souce any more. This has been designed out of the device. Hardware sources are stirred into the CSPRNG (Yarrow, Fortuna) like any other entropy source. Pluggable modules may be written by third parties for additional sources. The harvesting structures and consequently the locking have been simplified. Entropy harvesting is done in a more general way (the documentation for this will follow). There is some GREAT entropy to be had in the UMA allocator, but it is disabled for now as messing with that is likely to annoy many people. The venerable (but effective) Yarrow algorithm, which is no longer supported by its authors now has an alternative, Fortuna. For now, Yarrow is retained as the default algorithm, but this may be changed using a kernel option. It is intended to make Fortuna the default algorithm for 11.0. Interested parties are encouraged to read ISBN 978-0-470-47424-2 "Cryptography Engineering" By Ferguson, Schneier and Kohno for Fortuna's gory details. Heck, read it anyway. Many thanks to Arthur Mesh who did early grunt work, and who got caught in the crossfire rather more than he deserved to. My thanks also to folks who helped me thresh this out on whiteboards and in the odd "Hallway track", or otherwise. My Nomex pants are on. Let the feedback commence! Reviewed by: trasz,des(partial),imp(partial?),rwatson(partial?) Approved by: so(des) Notes: svn path=/head/; revision=273872
2013-10-12Fix a problem where the priority order of yarrow,dummy can get reversedMark Murray
to dummy,yarrow and break the usability of /dev/random. Fix the name of the tunable to something logical that 'sysctl kern.random' emits. Submitted by: des@ (the idea, code by me) Notes: svn path=/projects/random_number_generator/; revision=256399
2013-10-09Add missing include guards and move the existing ones out of theDag-Erling Smørgrav
implementation namespace. Notes: svn path=/projects/random_number_generator/; revision=256182
2013-10-08Fix some just-noticed problems:Mark Murray
o Allow this to work with "nodevice random" by fixing where the MALLOC pool is defined. o Fix the explicit reseed code. This was correct as submitted, but in the project branch doesn't need to set the "seeded" bit as this is done correctly in the "unblock" function. o Remove some debug ifdeffing. o Adjust comments. Notes: svn path=/projects/random_number_generator/; revision=256168
2013-10-06SNAPSHOT.Mark Murray
Simplify the malloc pools; We only need one for this device. Simplify the harvest queue. Marginally improve the entropy pool hashing, making it a bit faster in the process. Connect up the hardware "live" source harvesting. This is simplistic for now, and will need to be made rate-adaptive. All of the above passes a compile test but needs to be debugged. Notes: svn path=/projects/random_number_generator/; revision=256081
2013-10-04Snapshot. This passes the build test, but has not yet been finished or debugged.Mark Murray
Contains: * Refactor the hardware RNG CPU instruction sources to feed into the software mixer. This is unfinished. The actual harvesting needs to be sorted out. Modified by me (see below). * Remove 'frac' parameter from random_harvest(). This was never used and adds extra code for no good reason. * Remove device write entropy harvesting. This provided a weak attack vector, was not very good at bootstrapping the device. To follow will be a replacement explicit reseed knob. * Separate out all the RANDOM_PURE sources into separate harvest entities. This adds some secuity in the case where more than one is present. * Review all the code and fix anything obviously messy or inconsistent. Address som review concerns while I'm here, like rename the pseudo-rng to 'dummy'. Submitted by: Arthur Mesh <arthurmesh@gmail.com> (the first item) Notes: svn path=/projects/random_number_generator/; revision=256042
2013-08-241) example (partially humorous random_adaptor, that I call "EXAMPLE")Mark Murray
* It's not meant to be used in a real system, it's there to show how the basics of how to create interfaces for random_adaptors. Perhaps it should belong in a manual page 2) Move probe.c's functionality in to random_adaptors.c * rename random_ident_hardware() to random_adaptor_choose() 3) Introduce a new way to choose (or select) random_adaptors via tunable "rngs_want" It's a list of comma separated names of adaptors, ordered by preferences. I.e.: rngs_want="yarrow,rdrand" Such setting would cause yarrow to be preferred to rdrand. If neither of them are available (or registered), then system will default to something reasonable (currently yarrow). If yarrow is not present, then we fall back to the adaptor that's first on the list of registered adaptors. 4) Introduce a way where RNGs can play a role of entropy source. This is mostly useful for HW rngs. The way I envision this is that every HW RNG will use this functionality by default. Functionality to disable this is also present. I have an example of how to use this in random_adaptor_example.c (see modload event, and init function) 5) fix kern.random.adaptors from kern.random.adaptors: yarrowpanicblock to kern.random.adaptors: yarrow,panic,block 6) add kern.random.active_adaptor to indicate currently selected adaptor: root@freebsd04:~ # sysctl kern.random.active_adaptor kern.random.active_adaptor: yarrow Submitted by: Arthur Mesh <arthurmesh@gmail.com> Notes: svn path=/projects/random_number_generator/; revision=254784
2013-08-09* Add random_adaptors.[ch] which is basically a store of random_adaptor's.David E. O'Brien
random_adaptor is basically an adapter that plugs in to random(4). random_adaptor can only be plugged in to random(4) very early in bootup. Unplugging random_adaptor from random(4) is not supported, and is probably a bad idea anyway, due to potential loss of entropy pools. We currently have 3 random_adaptors: + yarrow + rdrand (ivy.c) + nehemeiah * Remove platform dependent logic from probe.c, and move it into corresponding registration routines of each random_adaptor provider. probe.c doesn't do anything other than picking a specific random_adaptor from a list of registered ones. * If the kernel doesn't have any random_adaptor adapters present then the creation of /dev/random is postponed until next random_adaptor is kldload'ed. * Fix randomdev_soft.c to refer to its own random_adaptor, instead of a system wide one. Submitted by: arthurmesh@gmail.com, obrien Obtained from: Juniper Networks Reviewed by: so (des) Notes: svn path=/head/; revision=254147
2013-07-31Back out r253779 & r253786.David E. O'Brien
Notes: svn path=/head/; revision=253845
2013-07-29Decouple yarrow from random(4) device.David E. O'Brien
* Make Yarrow an optional kernel component -- enabled by "YARROW_RNG" option. The files sha2.c, hash.c, randomdev_soft.c and yarrow.c comprise yarrow. * random(4) device doesn't really depend on rijndael-*. Yarrow, however, does. * Add random_adaptors.[ch] which is basically a store of random_adaptor's. random_adaptor is basically an adapter that plugs in to random(4). random_adaptor can only be plugged in to random(4) very early in bootup. Unplugging random_adaptor from random(4) is not supported, and is probably a bad idea anyway, due to potential loss of entropy pools. We currently have 3 random_adaptors: + yarrow + rdrand (ivy.c) + nehemeiah * Remove platform dependent logic from probe.c, and move it into corresponding registration routines of each random_adaptor provider. probe.c doesn't do anything other than picking a specific random_adaptor from a list of registered ones. * If the kernel doesn't have any random_adaptor adapters present then the creation of /dev/random is postponed until next random_adaptor is kldload'ed. * Fix randomdev_soft.c to refer to its own random_adaptor, instead of a system wide one. Submitted by: arthurmesh@gmail.com, obrien Obtained from: Juniper Networks Reviewed by: obrien Notes: svn path=/head/; revision=253779
2013-07-09Refactor random_systat to be a *random_systat. This avoids unnecessaryDavid E. O'Brien
structure copying in random_ident_hardware(). This change will also help further modularization of random(4) subsystem. Submitted by: arthurmesh@gmail.com Reviewed by: obrien Obtained from: Juniper Networks Notes: svn path=/head/; revision=253122
2005-12-20Remove GIANT from device random.Paul Saab
Submitted by: ups Notes: svn path=/head/; revision=153575
2004-04-16Attempts to make this device Giant-free were ill-conceived asMark Murray
uiomove(9) is not properly locked. So, return to NEEDGIANT mode. Later, when uiomove is finely locked, I'll revisit. While I'm here, provide some temporary debugging output to help catch blocking startups. Notes: svn path=/head/; revision=128321
2004-04-09Reorganise the entropy device so that high-yield entropy sourcesMark Murray
can more easily be used INSTEAD OF the hard-working Yarrow. The only hardware source used at this point is the one inside the VIA C3 Nehemiah (Stepping 3 and above) CPU. More sources will be added in due course. Contributions welcome! Notes: svn path=/head/; revision=128059
2003-11-17Overhaul the entropy device:Mark Murray
o Each source gets its own queue, which is a FIFO, not a ring buffer. The FIFOs are implemented with the sys/queue.h macros. The separation is so that a low entropy/high rate source can't swamp the harvester with low-grade entropy and destroy the reseeds. o Each FIFO is limited to 256 (set as a macro, so adjustable) events queueable. Full FIFOs are ignored by the harvester. This is to prevent memory wastage, and helps to keep the kernel thread CPU usage within reasonable limits. o There is no need to break up the event harvesting into ${burst} sized chunks, so retire that feature. o Break the device away from its roots with the memory device, and allow it to get its major number automagically. Notes: svn path=/head/; revision=122871
2002-03-03Massive lint-inspired cleanup.Mark Murray
Remove unneeded includes. Deal with unused function arguments. Resolve a boatload of signed/unsigned imcompatabilities. Etc. Notes: svn path=/head/; revision=91600
2001-09-10Fix a minor buglet/typo here that gcc3 complains about.Peter Wemm
Notes: svn path=/head/; revision=83267
2001-03-10Very large makeover of the /dev/random driver.Mark Murray
o Separate the kernel stuff from the Yarrow algorithm. Yarrow is now well contained in one source file and one header. o Replace the Blowfish-based crypto routines with Rijndael-based ones. (Rijndael is the new AES algorithm). The huge improvement in Rijndael's key-agility over Blowfish means that this is an extremely dramatic improvement in speed, and makes a heck of a difference in its (lack of) CPU load. o Clean up the sysctl's. At BDE's prompting, I have gone back to static sysctls. o Bug fixes. The streamlining of the crypto stuff enabled me to find and fix some bugs. DES also found a bug in the reseed routine which is fixed. o Change the way reseeds clear "used" entropy. Previously, only the source(s) that caused a reseed were cleared. Now all sources in the relevant pool(s) are cleared. o Code tidy-up. Mostly to make it (nearly) 80-column compliant. Notes: svn path=/head/; revision=74072