Commit Graph

173 Commits

Author SHA1 Message Date
Matt Caswell 69b9a99296 Don't call ossl_assert on the result of bn_wexpand
bn_wexpand can fail as the result of a memory allocation failure. We
should not be calling ossl_assert() on its result because it can fail in
normal operation.

Found via the reproducible error injection in #21668

Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/21725)
2023-08-14 14:32:06 +01:00
Dimitri Papadopoulos 060f370ebc Fix a typo found by codespell in a variable name
The change is limited to a single C file.

CLA: trivial

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20912)
2023-05-11 12:26:00 +10:00
Bernd Edlinger f06ef1657a Alternative fix for CVE-2022-4304
This is about a timing leak in the topmost limb
of the internal result of RSA_private_decrypt,
before the padding check.

There are in fact at least three bugs together that
caused the timing leak:

First and probably most important is the fact that
the blinding did not use the constant time code path
at all when the RSA object was used for a private
decrypt, due to the fact that the Montgomery context
rsa->_method_mod_n was not set up early enough in
rsa_ossl_private_decrypt, when BN_BLINDING_create_param
needed it, and that was persisted as blinding->m_ctx,
although the RSA object creates the Montgomery context
just a bit later.

Then the infamous bn_correct_top was used on the
secret value right after the blinding was removed.

And finally the function BN_bn2binpad did not use
the constant-time code path since the BN_FLG_CONSTTIME
was not set on the secret value.

In order to address the first problem, this patch
makes sure that the rsa->_method_mod_n is initialized
right before the blinding context.

And to fix the second problem, we add a new utility
function bn_correct_top_consttime, a const-time
variant of bn_correct_top.

Together with the fact, that BN_bn2binpad is already
constant time if the flag BN_FLG_CONSTTIME is set,
this should eliminate the timing oracle completely.

In addition the no-asm variant may also have
branches that depend on secret values, because the last
invocation of bn_sub_words in bn_from_montgomery_word
had branches when the function is compiled by certain
gcc compiler versions, due to the clumsy coding style.

So additionally this patch stream-lined the no-asm
C-code in order to avoid branches where possible and
improve the resulting code quality.

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20281)
2023-04-04 12:13:27 +02:00
Richard Levitte c9466f38e0 bn2bin(): Don't accept len < 0
Test included

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20033)
2023-01-20 07:38:40 +00:00
Richard Levitte 1b24b5a1b4 bin2bn(): When len==0, just return a zero BIGNUM
This allows calls with s==NULL and len==0 to be safe.  It probably already
was, but address sanitizers could still complain.

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20033)
2023-01-20 07:38:30 +00:00
Richard Levitte e077455e9e Stop raising ERR_R_MALLOC_FAILURE in most places
Since OPENSSL_malloc() and friends report ERR_R_MALLOC_FAILURE, and
at least handle the file name and line number they are called from,
there's no need to report ERR_R_MALLOC_FAILURE where they are called
directly, or when SSLfatal() and RLAYERfatal() is used, the reason
`ERR_R_MALLOC_FAILURE` is changed to `ERR_R_CRYPTO_LIB`.

There were a number of places where `ERR_R_MALLOC_FAILURE` was reported
even though it was a function from a different sub-system that was
called.  Those places are changed to report ERR_R_{lib}_LIB, where
{lib} is the name of that sub-system.
Some of them are tricky to get right, as we have a lot of functions
that belong in the ASN1 sub-system, and all the `sk_` calls or from
the CRYPTO sub-system.

Some extra adaptation was necessary where there were custom OPENSSL_malloc()
wrappers, and some bugs are fixed alongside these changes.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19301)
2022-10-05 14:02:03 +02:00
Billy Brumley a644cb7c1c [crypto/bn] BN_consttime_swap: remove superfluous early exit
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18518)
2022-06-13 10:50:44 +02:00
Matt Caswell fecb3aae22 Update copyright year
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Release: yes
2022-05-03 13:34:51 +01:00
Kelvin Lee 649999dc57 bn_lib.c: Change Endianess check to as a binary condition.
This prevents VS2022 from mis-identify an uninitialized local pointer
variable.

CLA: trivial

Reviewed-by: Ben Kaduk <kaduk@mit.edu>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17567)
2022-02-10 15:20:30 +01:00
Dimitris Apostolou 07c5465e98 Fix typos
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17634)
2022-02-07 11:23:28 +11:00
Richard Levitte f5e8050fdc Add signed bn2bin and bin2bn functions
This adds the functions BN_signed_bin2bn(), BN_signed_bn2bin(),
BN_signed_lebin2bn(), BN_signed_bn2lebin(), BN_signed_native2bn(),
and BN_signed_bn2native(), all essentially doing the same job as
BN_bin2bn(), BN_bn2binpad(), BN_lebin2bn(), BN_bn2lebinpad(),
BN_native2bn(), and BN_bn2nativepad(), except that the 'signed'
ones operate on signed number bins in 2's complement form.

Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17139)
2022-01-20 17:58:08 +01:00
Richard Levitte c30de60185 [refactor] BIGNUM: Modify bin2bn() to work from least to most significant chunk
This will make it easier to introduce the possibility for signed input
numbers.

We also refactor the inner loop to simplify the calculation of each
bignum chunk.

Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17139)
2022-01-20 17:57:39 +01:00
Richard Levitte 4e26fe508b [refactor] BIGNUM: Modify bn2binpad()'s setup to be more like bin2bn()'s
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17139)
2022-01-20 17:57:39 +01:00
Richard Levitte c2cab43574 [refactor] BIGNUM: collapse BN_bin2bn() and BN_lebin2bn() into one
BN_lebin2bn() is a block copy of BN_bin2bn() with just a couple of
very minute details changed.  For better maintainability, we collapse
them into the internal function bn2bin(), and change BN_bin2bn() and
BN_lebin2bn() to become simple wrappers.

Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17139)
2022-01-20 17:57:38 +01:00
Tomas Mraz 858d5ac16d bn2binpad: Use memset as the buffer will be used later
Apparently using OPENSSL_cleanse() confuses the fuzzer so it
makes the buffer to appear uninitialized. And memset can be
safely used here and it is also potentially faster.

Fixes #17237

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/17240)
2021-12-13 11:32:39 +01:00
Richard Levitte 9311d0c471 Convert all {NAME}err() in crypto/ to their corresponding ERR_raise() call
This includes error reporting for libcrypto sub-libraries in surprising
places.

This was done using util/err-to-raise

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/13318)
2020-11-13 09:35:02 +01:00
aSoujyuTanaka 7a09fab2b3 Disable optimiization of BN_num_bits_word() for VS2005 ARM compiler due to
its miscompilation of the function.
https://mta.openssl.org/pipermail/openssl-users/2018-August/008465.html

Reviewed-by: Mark J. Cox <mark@awe.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11526)
2020-07-15 23:03:22 +02:00
Richard Levitte 310a0edbd0 BN: Check endianness in run-time, in BN_native2bn() and BN_bn2nativepad()
The code relied on B_ENDIAN being defined on all big-endian platform,
which turned out to not always be the case.

Fixes #12387

Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/12390)
2020-07-11 10:00:33 +02:00
Matt Caswell 33388b44b6 Update copyright year
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11616)
2020-04-23 13:55:52 +01:00
Nicola Tuveri 2d9167ed0b [BN] harden `BN_copy()` against leaks from memory accesses
`BN_copy()` (and indirectly `BN_dup()`) do not propagate the
`BN_FLG_CONSTTIME` flag: the propagation has been turned on and off a
few times in the past years, because in some conditions it has shown
unintended consequences in some code paths.

Without turning the propagation on once more, we can still improve
`BN_copy()` by avoiding to leak `src->top` in case `src` is flagged with
`BN_FLG_CONSTTIME`.
In this case we can instead use `src->dmax` as the number of words
allocated for `dst` and for the `memcpy` operation.

Barring compiler or runtime optimizations, if the caller provides `src`
flagged as const time and preallocated to a public size, no leak should
happen due to the copy operation.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/10631)
2020-02-18 19:11:10 +02:00
Richard Levitte 00db8c60aa Update source files for pre-3.0 deprecation
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10364)
2019-11-07 11:37:25 +01:00
Dr. Matthias St. Pierre 706457b7bd 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/9333)
2019-09-28 20:26:35 +02:00
Nicola Tuveri 1b338abe3a Uniform BN_bn2binpad() and BN_bn2lebinpad() implementations
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/9511)
2019-09-07 02:06:29 +03:00
Nicola Tuveri 8b44198b91 Make BN_num_bits() consttime upon BN_FLG_CONSTTIME
This issue was partially addressed by commit
972c87dfc7, which hardened its callee
BN_num_bits_word() to avoid leaking the most-significant word of its
argument via branching and memory access pattern.
The commit message also reported:
> There are a few places where BN_num_bits is called on an input where
> the bit length is also secret. This does *not* fully resolve those
> cases as we still only look at the top word.

BN_num_bits() is called directly or indirectly (e.g., through
BN_num_bytes() or BN_bn2binpad() ) in various parts of the `crypto/ec`
code, notably in all the currently supported implementations of scalar
multiplication (in the generic path through ec_scalar_mul_ladder() as
well as in dedicated methods like ecp_nistp{224,256,521}.c and
ecp_nistz256.c).

Under the right conditions, a motivated SCA attacker could retrieve the
secret bitlength of a secret nonce through this vulnerability,
potentially leading, ultimately, to recover a long-term secret key.

With this commit, exclusively for BIGNUMs that are flagged with
BN_FLG_CONSTTIME, instead of accessing only bn->top, all the limbs of
the BIGNUM are accessed up to bn->dmax and bitwise masking is used to
avoid branching.

Memory access pattern still leaks bn->dmax, the size of the lazily
allocated buffer for representing the BIGNUM, which is inevitable with
the current BIGNUM architecture: reading past bn->dmax would be an
out-of-bound read.
As such, it's the caller responsibility to ensure that bn->dmax does not
leak secret information, by explicitly expanding the internal BIGNUM
buffer to a public value sufficient to avoid any lazy reallocation
while manipulating it: this should be already done at the top level
alongside setting the BN_FLG_CONSTTIME.

Thanks to David Schrammel and Samuel Weiser for reporting this issue
through responsible disclosure.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/9511)
2019-09-07 02:06:29 +03:00
Pauli 82925f9dd0 Avoid double clearing some BIGNUMs
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9438)
2019-07-23 16:54:52 +10:00
Shane Lontis ce1415ed2c Added NULL check to BN_clear() & BN_CTX_end()
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8518)
2019-03-19 07:25:48 +01:00
Richard Levitte fa4d419c25 Add BN_native2bn and BN_bn2nativepad, for native BIGNUM import/export
These are a couple of utility functions, to make import and export of
BIGNUMs to byte strings in platform native for (little-endian or
big-endian) easier.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8346)
2019-02-26 22:44:48 +01:00
Matt Caswell 576129cd72 Ensure bn_cmp_words can handle the case where n == 0
Thanks to David Benjamin who reported this, performed the analysis and
suggested the patch. I have incorporated some of his analysis in the
comments below.

This issue can cause an out-of-bounds read. It is believed that this was
not reachable until the recent "fixed top" changes. Analysis has so far
only identified one code path that can encounter this - although it is
possible that others may be found. The one code path only impacts 1.0.2 in
certain builds. The fuzzer found a path in RSA where iqmp is too large. If
the input is all zeros, the RSA CRT logic will multiply a padded zero by
iqmp. Two mitigating factors:

- Private keys which trip this are invalid (iqmp is not reduced mod p).
Only systems which take untrusted private keys care.
- In OpenSSL 1.1.x, there is a check which rejects the oversize iqmp,
so the bug is only reproducible in 1.0.2 so far.

Fortunately, the bug appears to be relatively harmless. The consequences of
bn_cmp_word's misbehavior are:

- OpenSSL may crash if the buffers are page-aligned and the previous page is
non-existent.
- OpenSSL will incorrectly treat two BN_ULONG buffers as not equal when they
are equal.
- Side channel concerns.

The first is indeed a concern and is a DoS bug. The second is fine in this
context. bn_cmp_word and bn_cmp_part_words are used to compute abs(a0 - a1)
in Karatsuba. If a0 = a1, it does not matter whether we use a0 - a1 or
a1 - a0. The third would be worth thinking about, but it is overshadowed
by the entire Karatsuba implementation not being constant time.

Due to the difficulty of tripping this and the low impact no CVE is felt
necessary for this issue.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8326)
2019-02-25 16:26:56 +00:00
Richard Levitte 367ace6870 Following the license change, modify the boilerplates in crypto/bn/
[skip ci]

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7777)
2018-12-06 14:31:21 +01:00
Richard Levitte fcd2d5a612 Refactor the computation of API version limits
Previously, the API version limit was indicated with a numeric version
number.  This was "natural" in the pre-3.0.0 because the version was
this simple number.

With 3.0.0, the version is divided into three separate numbers, and
it's only the major number that counts, but we still need to be able
to support pre-3.0.0 version limits.

Therefore, we allow OPENSSL_API_COMPAT to be defined with a pre-3.0.0
style numeric version number or with a simple major number, i.e. can
be defined like this for any application:

    -D OPENSSL_API_COMPAT=0x10100000L
    -D OPENSSL_API_COMPAT=3

Since the pre-3.0.0 numerical version numbers are high, it's easy to
distinguish between a simple major number and a pre-3.0.0 numerical
version number and to thereby support both forms at the same time.

Internally, we define the following macros depending on the value of
OPENSSL_API_COMPAT:

    OPENSSL_API_0_9_8
    OPENSSL_API_1_0_0
    OPENSSL_API_1_1_0
    OPENSSL_API_3

They indicate that functions marked for deprecation in the
corresponding major release shall not be built if defined.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7724)
2018-12-06 12:24:48 +01:00
Billy Brumley 900fd8f375 Clean up BN_consttime_swap.
Updated "condition" logic lifted from Theo Buehler's LibreSSL commit 517358603b

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/7619)
2018-11-26 17:52:33 +02:00
Billy Brumley dd41956d80 [crypto/bn] swap BN_FLG_FIXED_TOP too
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/7599)
2018-11-10 04:08:09 +02:00
Andy Polyakov 324b956052 bn/bn_lib.c: conceal even memmory access pattern in bn2binpad.
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/6915)
2018-08-23 22:20:35 +02:00
Andy Polyakov 83e034379f bn/bn_lib.c address Coverity nit in bn2binpad.
It was false positive, but one can as well view it as readability issue.
Switch even to unsigned indices because % BN_BYTES takes 4-6 instructions
with signed dividend vs. 1 (one) with unsigned.

Reviewed-by: Rich Salz <rsalz@openssl.org>
2018-07-18 16:04:24 +02:00
Andy Polyakov 89d8aade5f bn/bn_lib.c: make BN_bn2binpad computationally constant-time.
"Computationally constant-time" means that it might still leak
information about input's length, but only in cases when input
is missing complete BN_ULONG limbs. But even then leak is possible
only if attacker can observe memory access pattern with limb
granularity.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5254)
2018-07-14 13:36:35 +02:00
Andy Polyakov 305b68f1a2 bn/bn_lib.c: add BN_FLG_FIXED_TOP flag.
The new flag marks vectors that were not treated with bn_correct_top,
in other words such vectors are permitted to be zero padded. For now
it's BN_DEBUG-only flag, as initial use case for zero-padded vectors
would be controlled Montgomery multiplication/exponentiation, not
general purpose. For general purpose use another type might be more
appropriate. Advantage of this suggestion is that it's possible to
back-port it...

bn/bn_div.c: fix memory sanitizer problem.
bn/bn_sqr.c: harmonize with BN_mul.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: David Benjamin <davidben@google.com>
(Merged from https://github.com/openssl/openssl/pull/6662)
2018-07-12 14:52:05 +02:00
Andy Polyakov e42395e637 bn/bn_lib.c: remove bn_check_top from bn_expand2.
Trouble is that addition is postponing expansion till carry is
calculated, and if addition carries, top word can be zero, which
triggers assertion in bn_check_top.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: David Benjamin <davidben@google.com>
(Merged from https://github.com/openssl/openssl/pull/6662)
2018-07-12 14:50:54 +02:00
Billy Brumley 9e5b50b54d fix: BN_swap mishandles flags
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6099)
2018-04-27 09:54:37 +01:00
Billy Brumley 39df51522b Remove superfluous NULL checks. Add Andy's BN_FLG comment.
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6009)
2018-04-23 19:14:25 +01:00
Billy Brumley 40e48e5458 Elliptic curve scalar multiplication with timing attack defenses
Co-authored-by: Nicola Tuveri <nic.tuv@gmail.com>
Co-authored-by: Cesar Pereida Garcia <cesar.pereidagarcia@tut.fi>
Co-authored-by: Sohaib ul Hassan <soh.19.hassan@gmail.com>

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6009)
2018-04-23 19:14:25 +01:00
David Benjamin 972c87dfc7 Make BN_num_bits_word constant-time.
(This patch was written by Andy Polyakov. I only wrote the commit
message. Mistakes in the analysis are my fault.)

BN_num_bits, by way of BN_num_bits_word, currently leaks the
most-significant word of its argument via branching and memory access
pattern.

BN_num_bits is called on RSA prime factors in various places. These have
public bit lengths, but all bits beyond the high bit are secret. This
fully resolves those cases.

There are a few places where BN_num_bits is called on an input where the
bit length is also secret. This does *not* fully resolve those cases as
we still only look at the top word. Today, that is guaranteed to be
non-zero, but only because of the long-standing bn_correct_top timing
leak. Once that is fixed, a constant-time BN_num_bits on such inputs
must count bits on each word.

Instead, those cases should not call BN_num_bits at all. In particular,
BN_mod_exp_mont_consttime uses the exponent bit width to pick windows,
but it should be using the maximum bit width. The next patch will fix
this.

Thanks to Dinghao Wu, Danfeng Zhang, Shuai Wang, Pei Wang, and Xiao Liu
for reporting this issue.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5154)
2018-02-01 21:44:18 +01:00
Richard Levitte 48e5119a6b Copyright update of more files that have changed this year
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/5110)
2018-01-19 13:34:03 +01:00
Matt Caswell 7d461736f7 Revert BN_copy() flag copy semantics change
Commit 9f9442918a changed the semantics of BN_copy() to additionally
copy the BN_FLG_CONSTTIME flag if it is set. This turns out to be
ill advised as it has unintended consequences. For example calling
BN_mod_inverse_no_branch() can sometimes return a result with the flag
set and sometimes not as a result. This can lead to later failures if we
go down code branches that do not support constant time, but check for
the presence of the flag.

The original commit was made due to an issue in BN_MOD_CTX_set(). The
original PR fixed the problem in that function, but it was changed in
review to fix it in BN_copy() instead. The solution seems to be to revert
the BN_copy() change and go back to the originally proposed way.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/5080)
2018-01-16 15:19:01 +00:00
Matt Caswell c9fe362303 Correct value for BN_security_bits()
The function BN_security_bits() uses the values from SP800-57 to assign
security bit values for different FF key sizes. However the value for 192
security bits is wrong. SP800-57 has it as 7680 but the code had it as
7690.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4546)
2017-10-23 14:00:26 +01:00
KaoruToda 26a7d938c9 Remove parentheses of return.
Since return is inconsistent, I removed unnecessary parentheses and
unified them.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4541)
2017-10-18 16:05:06 +01:00
Dr. Stephen Henson 5f2d9c4d26 Support constant BN for DH parameters
If BN_FLG_STATIC_DATA is set don't cleanse a->d as it will reside
in read only memory. If BN_FLG_MALLOCED is not set don't modify the
BIGNUM at all.

This change applies to BN_clear_free() and BN_free(). Now the BIGNUM
structure is opaque applications cannot create a BIGNUM structure
without BN_FLG_MALLOCED being set so they are unaffected.

Update internal DH routines so they only copy pointers for read only
parameters.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4485)
2017-10-12 02:40:30 +01:00
KaoruToda 208fb891e3 Since return is inconsistent, I removed unnecessary parentheses and
unified them.
- return (0); -> return 0;
- return (1); -> return 1;
- return (-1); -> return -1;

Reviewed-by: Stephen Henson <steve@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4500)
2017-10-09 13:17:09 +01:00
Samuel Weiser 9f9442918a BN_copy now propagates BN_FLG_CONSTTIME
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4377)
2017-09-27 10:03:37 +01:00
Matt Caswell d08086645f Ensure we don't call memcpy with a NULL pointer
Commit d5aa14dd simplified the bn_expand_internal() and BN_copy() functions.
Unfortunately it also removed some checks which are still required,
otherwise we call memcpy passing in NULL which is not allowed.

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2836)
2017-03-03 23:49:24 +00:00
Emilia Kasper d5aa14dde5 Remove memcpy unrolling in bn_lib.c
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
2017-02-28 19:47:36 +01:00