In pull request #4328 the seeding of the DRBG via RAND_add()/RAND_seed()
was implemented by buffering the data in a random pool where it is
picked up later by the rand_drbg_get_entropy() callback. This buffer
was limited to the size of 4096 bytes.
When a larger input was added via RAND_add() or RAND_seed() to the DRBG,
the reseeding failed, but the error returned by the DRBG was ignored
by the two calling functions, which both don't return an error code.
As a consequence, the data provided by the application was effectively
ignored.
This commit fixes the problem by a more efficient implementation which
does not copy the data in memory and by raising the buffer the size limit
to INT32_MAX (2 gigabytes). This is less than the NIST limit of 2^35 bits
but it was chosen intentionally to avoid platform dependent problems
like integer sizes and/or signed/unsigned conversion.
Additionally, the DRBG is now less permissive on errors: In addition to
pushing a message to the openssl error stack, it enters the error state,
which forces a reinstantiation on next call.
Thanks go to Dr. Falko Strenzke for reporting this issue to the
openssl-security mailing list. After internal discussion the issue
has been categorized as not being security relevant, because the DRBG
reseeds automatically and is fully functional even without additional
randomness provided by the application.
Fixes#7381
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7382)
Fail harshly (in debug builds) when rand_pool_acquire_entropy isn't
delivering the required amount of entropy. In release builds, this
produces an error with details.
We also take the opportunity to modernise the types used.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5857)
There is a requirements of having access to a live entropy source
which we can't do with the default callbacks. If you need prediction
resistance you need to set up your own callbacks that follow the
requirements of NIST SP 800-90C.
Reviewed-by: Dr. Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
GH: #5402
This commit adds a new api RAND_DRBG_set_defaults() which sets the
default type and flags for new DRBG instances. See also #5576.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5632)
Fixes#4403
This commit moves the internal header file "internal/rand.h" to
<openssl/rand_drbg.h>, making the RAND_DRBG API public.
The RAND_POOL API remains private, its function prototypes were
moved to "internal/rand_int.h" and converted to lowercase.
Documentation for the new API is work in progress on GitHub #5461.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5462)
We currently don't support the algorithm from NIST SP 800-90C
10.1.2 to use a weaker DRBG as source
Reviewed-by: Dr. Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
GH: #5506
In PR #5295 it was decided that the locking api should remain private
and used only inside libcrypto. However, the locking functions were added
back to `libcrypto.num` by `mkdef.pl`, because the function prototypes
were still listed in `internal/rand.h`. (This header contains functions
which are internal, but shared between libcrypto and libssl.)
This commit moves the prototypes to `rand_lcl.h` and changes the names
to lowercase, following the convention therein. It also corrects an
outdated documenting comment.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5375)
This commit adds three new accessors to the internal DRBG lock
int RAND_DRBG_lock(RAND_DRBG *drbg)
int RAND_DRBG_unlock(RAND_DRBG *drbg)
int RAND_DRBG_enable_locking(RAND_DRBG *drbg)
The three shared DRBGs are intended to be used concurrently, so they
have locking enabled by default. It is the callers responsibility to
guard access to the shared DRBGs by calls to RAND_DRBG_lock() and
RAND_DRBG_unlock().
All other DRBG instances don't have locking enabled by default, because
they are intendended to be used by a single thread. If it is desired,
locking can be enabled by using RAND_DRBG_enable_locking().
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5294)
The DRGB concept described in NIST SP 800-90A provides for having different
algorithms to generate random output. In fact, the FIPS object module used to
implement three of them, CTR DRBG, HASH DRBG and HMAC DRBG.
When the FIPS code was ported to master in #4019, two of the three algorithms
were dropped, and together with those the entire code that made RAND_DRBG
generic was removed, since only one concrete implementation was left.
This commit restores the original generic implementation of the DRBG, making it
possible again to add additional implementations using different algorithms
(like RAND_DRBG_CHACHA20) in the future.
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4998)
Reseeding is handled very differently by the classic RAND_METHOD API
and the new RAND_DRBG api. These differences led to some problems when
the new RAND_DRBG was made the default OpenSSL RNG. In particular,
RAND_add() did not work as expected anymore. These issues are discussed
on the thread '[openssl-dev] Plea for a new public OpenSSL RNG API'
and in Pull Request #4328. This commit fixes the mentioned issues,
introducing the following changes:
- Replace the fixed size RAND_BYTES_BUFFER by a new RAND_POOL API which
facilitates collecting entropy by the get_entropy() callback.
- Don't use RAND_poll()/RAND_add() for collecting entropy from the
get_entropy() callback anymore. Instead, replace RAND_poll() by
RAND_POOL_acquire_entropy().
- Add a new function rand_drbg_restart() which tries to get the DRBG
in an instantiated state by all means, regardless of the current
state (uninstantiated, error, ...) the DRBG is in. If the caller
provides entropy or additional input, it will be used for reseeding.
- Restore the original documented behaviour of RAND_add() and RAND_poll()
(namely to reseed the DRBG immediately) by a new implementation based
on rand_drbg_restart().
- Add automatic error recovery from temporary failures of the entropy
source to RAND_DRBG_generate() using the rand_drbg_restart() function.
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/4328)
Ported from the last FIPS release, with DUAL_EC and SHA1 and the
self-tests removed. Since only AES-CTR is supported, other code
simplifications were done. Removed the "entropy blocklen" concept.
Moved internal functions to new include/internal/rand.h.
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/3789)
Document an internal assumption that these are only for use with files,
and return an error if not. That made the code much simpler.
Leave it as writing 1024 bytes, even though we don't need more than 256
from a security perspective. But the amount isn't specified, now, so we
can change it later if we want.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3864)
Run perltidy on util/mkerr
Change some mkerr flags, write some doc comments
Make generated tables "const" when genearting lib-internal ones.
Add "state" file for mkerr
Renerate error tables and headers
Rationalize declaration of ERR_load_XXX_strings
Fix out-of-tree build
Add -static; sort flags/vars for options.
Also tweak code output
Moved engines/afalg to engines (from master)
Use -static flag
Standard engine #include's of errors
Don't linewrap err string tables unless necessary
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3392)
This was done by the following
find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
print unless $. == 1 && m@/\* .*\.[ch] \*/@;
close ARGV if eof; # Close file to reset $.
And then some hand-editing of other files.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
now use an internal RAND_METHOD. All dependencies to OpenSSL standard
PRNG are now removed: it is the applications resposibility to setup
the FIPS PRNG and initalise it.
Initial OpenSSL RAND_init_fips() function that will setup the DRBG
for the "FIPS capable OpenSSL".
sure they are available in opensslconf.h, by giving them names starting
with "OPENSSL_" to avoid conflicts with other packages and by making
sure e_os2.h will cover all platform-specific cases together with
opensslconf.h.
I've checked fairly well that nothing breaks with this (apart from
external software that will adapt if they have used something like
NO_KRB5), but I can't guarantee it completely, so a review of this
change would be a good thing.
returns int (1 = ok, 0 = not seeded). New function RAND_add() is the
same as RAND_seed() but takes an estimate of the entropy as an additional
argument.
