The additional data allocates 12K per DRBG instance in the
secure memory, which is not necessary. Also nonces are not
considered secret.

[extended tests]
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9424)

and remove duplicate rand_drbg_seedlen() implementation again.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7462)

(cherry picked from commit 1c615e4ce97715ae3af9255bc57be32a49687966)

... to make the intended use more clear and differentiate
it from the data member "adin_pool".
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7575)

(cherry picked from commit 31f32abb8eb2a3ebd8500e6e0460b4a6791e5ed7)

Reviewed-by: NMatthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7518)

Fixes #7394
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7399)

(cherry picked from commit a83dc59afa2e0207180d7218efed19b20d48de95)

In commit 8bf366519661 some renamings andd typo fixes were made
while adding back the DRBG-HMAC and DRBG-HASH implementation.
Since the commit could not be backported, a lot of unnecessary
differences between master and 1.1.1 were introduced.

These differences result in tiresome merge conflicts when
cherry-picking. To minimize these merge-conflicts, this patch
ports all 'non-feature' changes of commit 8bf366519661
(e.g., renamings of private variables, fixes of typographical
errors, comment changes) manually back to 1.1.1.

The commits a83dc59afa2e (#7399) and 8817215d5c52 (#7456)
failed to cherry-pick previously to 1.1.1, with this patch
they both cherry-pick without conflicts.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NBernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/7505)

This value is used to set DRBG_MAX_LENGTH
Reviewed-by: NMatthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/7467)

(cherry picked from commit f81b043ad856d8b9af5239a4978f8bd4b965dab9)

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: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7382)

(cherry picked from commit 3064b55134434a0b2850f07eff57120f35bb269a)

If a nonce is required and the get_nonce callback is NULL, request 50%
more entropy following NIST SP800-90Ar1 section 9.1.
Reviewed-by: NDr. Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
GH: #5503

Add some more exposition on why unlocked access to the global rand_fork_count
is safe, and provide a comment for the struct rand_drbg_st fork_count field.
Reviewed-by: NMatt Caswell <matt@openssl.org>
Reviewed-by: NMatthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/4110)

Reviewed-by: NRich Salz <rsalz@openssl.org>
GH: #5580

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: NRichard 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: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5462)

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: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5375)

The functions drbg_setup() and drbg_cleanup() used to duplicate a lot of
code from RAND_DRBG_new() and RAND_DRBG_free(). This duplication has been
removed, which simplifies drbg_setup() and makes drbg_cleanup() obsolete.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5294)

Reviewed-by: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NMatthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/4752)

Reviewed-by: NTim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5038)

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: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NTim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4998)

Every DRBG now supports automatic reseeding not only after a given
number of generate requests, but also after a specified time interval.
Signed-off-by: NDr. Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NKurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/4402)

A third shared DRBG is added, the so called master DRBG. Its sole purpose
is to reseed the two other shared DRBGs, the public and the private DRBG.
The randomness for the master DRBG is either pulled from the os entropy
sources, or added by the application using the RAND_add() call.

The master DRBG reseeds itself automatically after a given number of generate
requests, but can also be reseeded using RAND_seed() or RAND_add().
A reseeding of the master DRBG is automatically propagated to the public
and private DRBG. This construction fixes the problem, that up to now
the randomness provided by RAND_add() was added only to the public and
not to the private DRBG.
Signed-off-by: NDr. Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NKurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/4402)

The DRBG_RESEED state plays an analogue role to the |reseed_required_flag| in
Appendix B.3.4 of [NIST SP 800-90A Rev. 1]. The latter is a local variable,
the scope of which is limited to the RAND_DRBG_generate() function. Hence there
is no need for a DRBG_RESEED state outside of the generate function. This state
was removed and replaced by a local variable |reseed_required|.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NBen Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/4328)

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: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NBen Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/4328)

Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
GH: #4268

The DRBG callbacks 'get_entropy()' and 'cleanup_entropy()' are designed
in such a way that the randomness buffer does not have to be allocated
by the calling function. It receives the address of a dynamically
allocated buffer from get_entropy() and returns this address to
cleanup_entropy(), where it is freed. If these two calls are properly
paired, the address can be stored in a stack local variable of the
calling function, so there is no need for having a 'randomness' member
(and a 'filled' member) in 'RAND_DRBG'.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4266)

With the introduction of RAND_poll_ex(), the `RAND_add()` calls were
replaced by meaningless cb(...). This commit changes the 'cb(...)'
calls back to 'rand_add(...)' calls by changing the signature as follows:

-int RAND_poll_ex(RAND_poll_fn cb, void *arg);
+int RAND_poll_ex(RAND_poll_cb rand_add, void *arg);

Changed the function typedef name to 'RAND_poll_cb' to emphasize the fact
that the function type represents a callback function.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4266)

Unlike the NIST DRBG standard, entropy counts are in bits and
buffer lengths are in bytes. This has lead to some confusion and
errors in the past, see my comment on PR 3789.

To clarify the destinction between entropy counts and buffer lengths,
a 'len' suffix has been added to all member names of RAND_DRBG which
represent buffer lengths:

-   {min,max}_{entropy,adin,nonce,pers}
+   {min,max}_{entropy,adin,nonce,pers}len

This change makes naming also more consistent, as can be seen in the
diffs, for example:

-    else if (adinlen > drbg->max_adin) {
+    else if (adinlen > drbg->max_adinlen) {

Also replaced all 'ent's by 'entropy's, following a suggestion of Paul Dale.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4266)

Try to put DRBG and rand_bytes buffers in secure heap
Read the TSC fewer times (but it's still not enabled).
Short-circuit return in win RAND_poll_ex; other minor tweaks and
format-fixes.
Use the _bytes version of rdrand/rdseed
Fix ia32cap checks.
Reviewed-by: NBernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/4100)

Use atfork to count child forks, and reseed DRBG when the counts don't
match.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/4101)

Add a new global DRBG for private keys used by RAND_priv_bytes.

Add BN_priv_rand() and BN_priv_rand_range() which use RAND_priv_bytes().
Change callers to use the appropriate BN_priv... function.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/4076)

If RAND_add wraps around, XOR with existing. Add test to drbgtest that
does the wrap-around.

Re-order seeding and stop after first success.

Add RAND_poll_ex()

Use the DF and therefore lower RANDOMNESS_NEEDED.  Also, for child DRBG's,
mix in the address as the personalization bits.

Centralize the entropy callbacks, from drbg_lib to rand_lib.
(Conceptually, entropy is part of the enclosing application.)
Thanks to Dr. Matthias St Pierre for the suggestion.

Various code cleanups:
    -Make state an enum; inline RANDerr calls.
    -Add RAND_POLL_RETRIES (thanks Pauli for the idea)
    -Remove most RAND_seed calls from rest of library
    -Rename DRBG_CTX to RAND_DRBG, etc.
    -Move some code from drbg_lib to drbg_rand; drbg_lib is now only the
     implementation of NIST DRBG.
    -Remove blocklength
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/4019)

Add a new config param to specify how the CSPRNG should be seeded.
Illegal values or nonsensical combinations (e.g., anything other
than "os" on VMS or HP VOS etc) result in build failures.
Add RDSEED support.
Add RDTSC but leave it disabled for now pending more investigation.

Refactor and reorganization all seeding files (rand_unix/win/vms) so
that they are simpler.

Only require 128 bits of seeding material.

Many document improvements, including why to not use RAND_add() and the
limitations around using load_file/write_file.
Document RAND_poll().

Cleanup Windows RAND_poll and return correct status

More completely initialize the default DRBG.
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/3965)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3971)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3974)

As suggested by Kurt.
Reviewed-by: NBernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/3970)

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: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/3789)

Remove unused rand_hw_xor, MD/EVP indirection
Make rand_pseudo same as rand.
Cleanup formatting and ifdef control
Rename some things:
    - rand_meth to openssl_rand_meth; make it global
    - source file
    - lock/init functions, start per-thread state
    - ossl_meth_init to ossl_rand_init
Put state into RAND_STATE structure
And put OSSL_RAND_STATE into ossl_typ.h
Use "randomness" instead of "entropy"
Reviewed-by: NBen Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/3758)

Reviewed-by: NRichard Levitte <levitte@openssl.org>

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: NViktor Dukhovni <viktor@openssl.org>

Remove support for SHA0 and DSS0 (they were broken), and remove
the ability to attempt to build without SHA (it didn't work).
For simplicity, remove the option of not building various SHA algorithms;
you could argue that SHA_224/256/384/512 should be kept, since they're
like crypto algorithms, but I decided to go the other way.
So these options are gone:
	GENUINE_DSA         OPENSSL_NO_SHA0
	OPENSSL_NO_SHA      OPENSSL_NO_SHA1
	OPENSSL_NO_SHA224   OPENSSL_NO_SHA256
	OPENSSL_NO_SHA384   OPENSSL_NO_SHA512
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>