Commit graph

92 commits

Author SHA1 Message Date
Dr. Matthias St. Pierre
10cb54d75b rand_unix.c: correct include guard comments
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10050)

(cherry picked from commit 2a7e6ed86be20bd472696a3eafe5d20ec9579dab)
2019-10-19 00:08:04 +02:00
Kurt Roeckx
eee565ec4b Add defines for __NR_getrandom for all Linux architectures
Fixes: #10015

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
GH: #10044
(cherry picked from commit 4dcb150ea30f9bbfa7946e6b39c30a86aca5ed02)
2019-09-30 22:29:45 +02:00
Dr. Matthias St. Pierre
b5acbf9148 Reorganize local header files
Apart from public and internal header files, there is a third type called
local header files, which are located next to source files in the source
directory. Currently, they have different suffixes like

  '*_lcl.h', '*_local.h', or '*_int.h'

This commit changes the different suffixes to '*_local.h' uniformly.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9681)
2019-09-27 23:58:06 +02:00
Dr. Matthias St. Pierre
0c994d54af Reorganize private crypto header files
Currently, there are two different directories which contain internal
header files of libcrypto which are meant to be shared internally:

While header files in 'include/internal' are intended to be shared
between libcrypto and libssl, the files in 'crypto/include/internal'
are intended to be shared inside libcrypto only.

To make things complicated, the include search path is set up in such
a way that the directive #include "internal/file.h" could refer to
a file in either of these two directoroes. This makes it necessary
in some cases to add a '_int.h' suffix to some files to resolve this
ambiguity:

  #include "internal/file.h"      # located in 'include/internal'
  #include "internal/file_int.h"  # located in 'crypto/include/internal'

This commit moves the private crypto headers from

  'crypto/include/internal'  to  'include/crypto'

As a result, the include directives become unambiguous

  #include "internal/file.h"       # located in 'include/internal'
  #include "crypto/file.h"         # located in 'include/crypto'

hence the superfluous '_int.h' suffixes can be stripped.

The files 'store_int.h' and 'store.h' need to be treated specially;
they are joined into a single file.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9681)
2019-09-27 23:57:58 +02:00
Bernd Edlinger
1d36536457 Fix a strict warnings error in rand_pool_acquire_entropy
There was a warning about unused variables in this config:
./config --strict-warnings --with-rand-seed=rdcpu

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9687)

(cherry picked from commit e301c147a763f67dcc5ba63eb7e2ae40d83a68aa)
2019-09-10 10:03:04 +01:00
Dr. Matthias St. Pierre
5520695c73 drbg: add fork id to additional data on UNIX systems
Provides a little extra fork-safety on UNIX systems, adding to the
fact that all DRBGs reseed automatically when the fork_id changes.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9802)
2019-09-09 17:09:06 +01:00
Bernd Edlinger
ce1ab24163 Cleanup includes in rand_unix.c
Fixes #9757

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9761)

(cherry picked from commit 41ffd2ab09d24692c71850ccd7d5ff154196fe01)
2019-09-05 08:33:48 +02:00
Bernd Edlinger
aa24cc0195 Remove ifndef FIPS_MODE from rand_unix.c
This will never be the case for 1.1.1 so removed.

Fixes: comment 1 of #9757

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9762)
2019-09-05 08:25:18 +02:00
Pauli
f493bd6f94 Fix NITs in comments and CHANGES for DEVRANDOM seeded check.
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/9734)

(cherry picked from commit 46a9cc9451213039fd53f62733b2ccd04e853bb2)
2019-08-30 07:57:55 +10:00
Pauli
4bdab25717 Avoid overflowing FDSET when using select(2).
There is a problem in the rand_unix.c code when the random seed fd is greater
than or equal to FD_SETSIZE and the FDSET overruns its limit and walks the
stack.

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/9686)

(cherry picked from commit e1f8584d47)
2019-08-24 16:45:53 +10:00
Pauli
3ff98f5581 Start up DEVRANDOM entropy improvement for older Linux devices.
Improve handling of low entropy at start up from /dev/urandom by waiting for
a read(2) call on /dev/random to succeed.  Once one such call has succeeded,
a shared memory segment is created and persisted as an indicator to other
processes that /dev/urandom is properly seeded.

This does not fully prevent against attacks weakening the entropy source.
An attacker who has control of the machine early in its boot sequence
could create the shared memory segment preventing detection of low entropy
conditions.  However, this is no worse than the current situation.

An attacker would also be capable of removing the shared memory segment
and causing seeding to reoccur resulting in a denial of service attack.
This is partially mitigated by keeping the shared memory alive for the
duration of the process's existence.  Thus, an attacker would not only need
to have called call shmctl(2) with the IPC_RMID command but the system
must subsequently enter a state where no instances of libcrypto exist in
any process.  Even one long running process will prevent this attack.

The System V shared memory calls used here go back at least as far as
Linux kernel 2.0.  Linux kernels 4.8 and later, don't have a reliable way
to detect that /dev/urandom has been properly seeded, so a failure is raised
for this case (i.e. the getentropy(2) call has already failed).

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/9595)

[manual merge]
2019-08-20 16:19:20 +10:00
Bernd Edlinger
84814f7734 Add a fallback definition for __NR_getrandom for x86 linux
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9639)

(cherry picked from commit 038b381ecf)
2019-08-19 16:06:39 +02:00
Bernd Edlinger
31dd6414a0 Add a fallback definition for __NR_getrandom for ARM linux
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9619)

(cherry picked from commit 24d932ec84)
2019-08-19 07:06:56 +02:00
Rebecca Cran
444ec8d5e7 Fix UEFI build on FreeBSD by not including system headers
CLA: trivial

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Ben Kaduk <kaduk@mit.edu>
Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/9149)
2019-06-19 14:39:45 +02:00
Dr. Matthias St. Pierre
ad416c8058 Revert the DEVRANDOM_WAIT feature
The DEVRANDOM_WAIT feature added a select() call to wait for the
`/dev/random` device to become readable before reading from the
`/dev/urandom` device. It was introduced in commit 38023b87f0
in order to mitigate the fact that the `/dev/urandom` device
does not block until the initial seeding of the kernel CSPRNG
has completed, contrary to the behaviour of the `getrandom()`
system call.

It turned out that this change had negative side effects on
performance which were not acceptable. After some discussion it
was decided to revert this feature and leave it up to the OS
resp. the platform maintainer to ensure a proper initialization
during early boot time.

Fixes #9078

This partially reverts commit 38023b87f0.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>

(cherry picked from commit a08714e181)

(Merged from https://github.com/openssl/openssl/pull/9118)
2019-06-09 09:53:39 +02:00
Bernd Edlinger
c352bd07ed Fix seeding from random device w/o getrandom syscall
Use select to wait for /dev/random in readable state,
but do not actually read anything from /dev/random,
use /dev/urandom first.

Use linux define __NR_getrandom instead of the
glibc define SYS_getrandom, in case the kernel headers
are more current than the glibc headers.

Fixes #8215

Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/8251)

(cherry picked from commit 38023b87f0)
2019-03-01 18:29:56 +01:00
Matt Caswell
72a7a7021f Update copyright year
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8347)
2019-02-26 14:05:09 +00:00
Klotz, Tobias
b6d41ff733 Cleanup vxworks support to be able to compile for VxWorks 7
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/7569)

(cherry picked from commit 5c8b7b4caa)
2019-01-24 17:58:27 +01:00
Dr. Matthias St. Pierre
abf58ed319 rand_unix.c: open random devices on first use only
Commit c7504aeb64 (pr #6432) fixed a regression for applications in
chroot environments, which compensated the fact that the new OpenSSL CSPRNG
(based on the NIST DRBG) now reseeds periodically, which the previous
one didn't. Now the reseeding could fail in the chroot environment if the
DEVRANDOM devices were not present anymore and no other entropy source
(e.g. getrandom()) was available.

The solution was to keep the file handles for the DEVRANDOM devices open
by default. In fact, the fix did more than this, it opened the DEVRANDOM
devices early and unconditionally in rand_pool_init(), which had the
unwanted side effect that the devices were opened (and kept open) even
in cases when they were not used at all, for example when the getrandom()
system call was available. Due  to a bug (issue #7419) this even happened
when the feature was disabled by the application.

This commit removes the unconditional opening of all DEVRANDOM devices.
They will now only be opened (and kept open) on first use. In particular,
if getrandom() is available, the handles will not be opened unnecessarily.

This change does not introduce a regression for applications compiled for
libcrypto 1.1.0, because the SSLEAY RNG also seeds on first use. So in the
above constellation the CSPRNG will only be properly seeded if it is happens
before the forking and chrooting.

Fixes #7419

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7437)

(cherry picked from commit 8cfc19716c)
2018-11-08 16:41:24 +01:00
Dr. Matthias St. Pierre
35a34508ef Backport some DRBG renamings and typo fixes
In commit 8bf3665196 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 8bf3665196
(e.g., renamings of private variables, fixes of typographical
errors, comment changes) manually back to 1.1.1.

The commits a83dc59afa (#7399) and 8817215d5c (#7456)
failed to cherry-pick previously to 1.1.1, with this patch
they both cherry-pick without conflicts.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/7505)
2018-10-26 23:04:23 +02:00
Dr. Matthias St. Pierre
dbf0a49625 DRBG: fix reseeding via RAND_add()/RAND_seed() with large input
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)

(cherry picked from commit 3064b55134)
2018-10-16 22:32:42 +02:00
Dr. Matthias St. Pierre
b99f047f3f rand_unix.c: fix --with-rand-seed=none build
Fixes a compiler warning about an unused syscall_random()
and cleans up the OPENSSL_RAND_SEED preprocessor logic.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/779)

(cherry picked from commit d90e128be6)
2018-10-10 12:40:52 +02:00
Dr. Matthias St. Pierre
cca9962178 rand_unix.c: don't discard entropy bytes from /dev/*random
Don't discard partial reads from /dev/*random and retry instead.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6990)
2018-08-19 12:44:05 +02:00
Dr. Matthias St. Pierre
630ce41e83 rand_unix.c: don't discard entropy bytes from syscall_random()
Fixes #6978

Don't discard partial reads from syscall_random() and retry instead.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6990)
2018-08-19 12:44:05 +02:00
Dr. Matthias St. Pierre
9b5f1c8fd8 rand_unix.c: assimilate syscall_random() with getrandom(2)
Change return value type to ssize_t and ensure that a negative value
is returned only if a corresponding errno is set.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6990)
2018-08-19 12:44:05 +02:00
Andy Polyakov
a0e53000a8 rand/rand_unix.c: address macro redifinition warning.
Occasionally, e.g. when compiling for elderly glibc, you end up passing
-D_GNU_SOURCE on command line, and doing so triggered warning...

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6616)
2018-07-01 12:05:54 +02:00
Pauli
c7504aeb64 Modify the DEVRANDOM source so that the files are kept open persistently.
This allows operation inside a chroot environment without having the
random device present.

A new call, RAND_keep_random_devices_open(), has been introduced that can
be used to control file descriptor use by the random seed sources. Some
seed sources maintain open file descriptors by default, which allows
such sources to operate in a chroot(2) jail without the associated device
nodes being available.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/6432)
2018-06-27 07:15:36 +10:00
Andy Polyakov
8d58f0171e rand/rand_unix.c: mask getentropy ELF detection on HP-UX.
Unlike other ELF systems, HP-UX run-time linker fails to detect symbol
availability through weak declaration.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6583)
2018-06-25 16:45:09 +02:00
Dr. Matthias St. Pierre
748eb991f4 RAND_POOL: Add missing implementations for djgpp
Calling the functions rand_pool_add_{additional,nonce}_data()
in crypto/rand/rand_lib.c with no implementation for djgpp/MSDOS
causees unresolved symbols when linking with djgpp.

Reported and fixed by Gisle Vanem

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6421)
2018-06-15 08:13:03 +02:00
Andy Polyakov
913cebc8f4 rand/rand_unix.c: bypass DSO_global_lookup on ELF systems.
If built with no-dso, syscall_random remains "blind" to getentropy.
Since it's possible to detect symbol availability on ELF-based systems
without involving DSO module, bypass it.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/6436)
2018-06-09 14:45:05 +02:00
Andy Polyakov
46ceca3c91 rand/rand_unix.c: omit error from DSO_global_lookup.
If built with no-dso, DSO_global_lookup leaves "unsupported" message
in error queue. Since there is a fall-back code, it's unnecessary
distraction.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/6436)
2018-06-09 14:43:33 +02:00
Kurt Roeckx
1e653d0ff7 Fix checking the return value of getentropy()
Reviewed-by: Andy Polyakov <appro@openssl.org>
GH: #6405
2018-06-03 12:14:32 +02:00
Kurt Roeckx
2545f9446e Remove support for calling getrandom(), we now always call getentropy()
Only Linux and FreeBSD provide getrandom(), but they both also provide
getentropy() since the same version and we already tried to call that.

Reviewed-by: Andy Polyakov <appro@openssl.org>
GH: #6405
2018-06-03 12:14:26 +02:00
Kurt Roeckx
cf0891b8f1 Look up availability of getentropy() at runtime.
This will actually support most OSs, and at least adds support for
Solaris and OSX

Fixes: #6403
Reviewed-by: Andy Polyakov <appro@openssl.org>
GH: #6405
2018-06-03 12:14:20 +02:00
Kurt Roeckx
8f57662771 Add support for KERN_ARND to get random bytes on NetBSD
Reviewed-by: Andy Polyakov <appro@openssl.org>
GH: #6405
2018-06-03 12:14:12 +02:00
Richard Levitte
6ebb49f3f9 Change rand_pool_bytes_needed to handle less entropy than 1 per 8 bits
rand_pool_bytes_needed() was constructed in such a way that the
smallest acceptable entropy factor was 1 entropy bits per 8 bits of
data.  At the same time, we have a DRBG_MINMAX_FACTOR that allows
weaker source, as small as 1 bit of entropy per 128 bits of data.
The conclusion is that rand_pool_bytes_needed() needs to change to
support weaker entropy sources.  We therefore change the input of
entropy per byte to be an entropy factor instead.  This entropy factor
expresses how many bits of data it takes (on average) to get 1 bit of
entropy.

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/6150)
2018-05-02 10:18:29 +02:00
Kurt Roeckx
5b820d785d Fix usage of ossl_assert()
Reviewed-by: Andy Polyakov <appro@openssl.org>
GH: #6044
2018-04-23 18:45:53 +02:00
Kurt Roeckx
148796291e Add support for getrandom() or equivalent system calls and use them by default
Reviewed-by: Dr. Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
GH: #5910
2018-04-22 20:16:02 +02:00
Dr. Matthias St. Pierre
5bc6bcf82d DRBG: implement a get_nonce() callback
Fixes #5849

In pull request #5503 a fallback was added which adds a random nonce of
security_strength/2 bits if no nonce callback is provided. This change raised
the entropy requirements form 256 to 384 bit, which can cause problems on some
platforms (e.g. VMS, see issue #5849).

The requirements for the nonce are given in section 8.6.7 of NIST SP 800-90Ar1:

  A nonce may be required in the construction of a seed during instantiation
  in order to provide a security cushion to block certain attacks.
  The nonce shall be either:

  a) A value with at least (security_strength/2) bits of entropy, or

  b) A value that is expected to repeat no more often than a
     (security_strength/2)-bit random string would be expected to repeat.

  Each nonce shall be unique to the cryptographic module in which instantiation
  is performed, but need not be secret. When used, the nonce shall be considered
  to be a critical security parameter.

This commit implements a nonce of type b) in order to lower the entropy
requirements during instantiation back to 256 bits.

The formulation "shall be unique to the cryptographic module" above implies
that the nonce needs to be unique among (with high probability) among all
DRBG instances in "space" and "time". We try to achieve this goal by creating a
nonce of the following form

    nonce = app-specific-data || high-resolution-utc-timestamp || counter

Where || denotes concatenation. The application specific data can be something
like the process or group id of the application. A utc timestamp is used because
it increases monotonically, provided the system time is synchronized. This approach
may not be perfect yet for a FIPS evaluation, but it should be good enough for the
moment.

This commit also harmonizes the implementation of the get_nonce() and the
get_additional_data() callbacks and moves the platform specific parts from
rand_lib.c into rand_unix.c, rand_win.c, and rand_vms.c.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5920)
2018-04-13 20:49:28 +02:00
Richard Levitte
8e2bec9b8a Remove ambiguity in rand_pool_add[_end] return value
When these two functions returned zero, it could mean:

1. that an error occured.  In their case, the error is an overflow of
   the pool, i.e. the correct response from the caller would be to
   stop trying to fill the pool.
2. that there isn't enought entropy acquired yet, i.e. the correct
   response from the caller would be to try and add more entropy to
   the pool.

Because of this ambiguity, the returned zero turns out to be useless.
This change makes the returned value more consistent.  1 means the
addition of new entropy was successful, 0 means it wasn't.  To know if
the pool has been filled enough, the caller will have to call some
other function, such as rand_pool_entropy_available().

Fixes #5846

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/5876)
2018-04-04 20:14:51 +02:00
Dr. Matthias St. Pierre
6decf9436f Publish the RAND_DRBG API
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)
2018-03-15 18:58:38 +01:00
Matt Caswell
0d66475908 Update copyright year
Reviewed-by: Richard Levitte <levitte@openssl.org>
2018-02-27 13:59:42 +00:00
Kurt Roeckx
7296027956 Use both getrandom() and /dev/urandom by default on Linux.
getrandom() is now used on Linux by default when using Linux >= 3.17
and glibc >= 2.25

Reviewed-by: Rich Salz <rsalz@openssl.org>
GH: #5314
2018-02-13 21:15:30 +01:00
Dr. Matthias St. Pierre
c16de9d832 Fix reseeding issues of the public RAND_DRBG
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)
2017-10-18 08:39:20 -05:00
Pauli
07016a8a31 Move e_os.h to be the very first include.
cryptilib.h is the second.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4188)
2017-08-30 07:20:44 +10:00
Dr. Matthias St. Pierre
6969a3f49a DRBG: Remove 'randomness' buffer from 'RAND_DRBG'
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: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4266)
2017-08-28 08:58:50 -04:00
Dr. Matthias St. Pierre
4871fa49cd RAND: Rename the RAND_poll_ex() callback and its typedef
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: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4266)
2017-08-28 08:52:02 -04:00
Rich Salz
75e2c87765 Switch from ossl_rand to DRBG rand
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: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/4019)
2017-08-03 09:23:28 -04:00
Rich Salz
8389ec4b49 Add --with-rand-seed
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: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/3965)
2017-07-22 14:00:07 -04:00
Rich Salz
da8fc25a98 Start to overhaul RAND API
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: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/3758)
2017-07-15 01:51:34 -04:00