This partially fixes a bug where, on x86_64, BN_mod_exp_mont_consttime
would sometimes return m, the modulus, when it should have returned
zero. Thanks to Guido Vranken for reporting it. It is only a partial fix
because the same bug also exists in the "rsaz" codepath.
The bug only affects zero outputs (with non-zero inputs), so we believe
it has no security impact on our cryptographic functions.
The fx is to delete lowercase bn_from_montgomery altogether, and have the
mont5 path use the same BN_from_montgomery ending as the non-mont5 path.
This only impacts the final step of the whole exponentiation and has no
measurable perf impact.
See the original BoringSSL commit
https://boringssl.googlesource.com/boringssl/+/13c9d5c69d04485a7a8840c12185c832026c8315
for further analysis.
Original-author: David Benjamin <davidben@google.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18510)
It uses AVX512_IFMA + AVX512_VL (with 256-bit wide registers) ISA to
keep lower power license.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14908)
Remove unused -DCONF_DEBUG and -DBN_CTX_DEBUG.
Rename REF_PRINT to REF_DEBUG for consistency, and add a new
tracing category and use it for printing reference counts.
Rename -DDEBUG_UNUSED to -DUNUSED_RESULT_DEBUG
Fix BN_DEBUG_RAND so it compiles and, when set, force DEBUG_RAND to
be set also.
Rename engine_debug_ref to be ENGINE_REF_PRINT also for consistency.
Fixes#15357
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15353)
The symbols renamed are:
RSAZ_amm52x20_x1_256
RSAZ_amm52x20_x2_256
rsaz_avx512ifma_eligible
RSAZ_mod_exp_avx512_x2
Additionally, RSAZ_exp52x20_x2_256 was made static
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/15445)
with AVX512_IFMA + AVX512_VL instructions, primarily for RSA CRT private key
operations. It uses 256-bit registers to avoid CPU frequency scaling issues.
The performance speedup for RSA2k signature on ICL is ~2x.
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/13750)
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)
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)
A number intended to treat the base as secret should not be branching on
whether it is zero. Test-wise, this is covered by existing tests in bnmod.txt.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6733)
Note that exported functions maintain original behaviour, so that
external callers won't observe difference. While internally we can
now perform Montogomery multiplication on fixed-length vectors, fixed
at modulus size. The new functions, bn_to_mont_fixed_top and
bn_mul_mont_fixed_top, are declared in bn_int.h, because one can use
them even outside bn, e.g. in RSA, DSA, ECDSA...
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: David Benjamin <davidben@google.com>
(Merged from https://github.com/openssl/openssl/pull/6662)
848113a30b added mitigation for a
side-channel attack. This commit extends approach to all code
paths for consistency.
[It also removes redundant white spaces introduced in last commit.]
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6480)
The One&Done attack, which is described in a paper to appear in the
USENIX Security'18 conference, uses EM emanations to recover the values
of the bits that are obtained using BN_is_bit_set while constructing
the value of the window in BN_mod_exp_consttime. The EM signal changes
slightly depending on the value of the bit, and since the lookup of a
bit is surrounded by highly regular execution (constant-time Montgomery
multiplications) the attack is able to isolate the (very brief) part of
the signal that changes depending on the bit. Although the change is
slight, the attack recovers it successfully >90% of the time on several
phones and IoT devices (all with ARM processors with clock rates around
1GHz), so after only one RSA decryption more than 90% of the bits in
d_p and d_q are recovered correctly, which enables rapid recovery of
the full RSA key using an algorithm (also described in the paper) that
modifies the branch-and-prune approach for a situation in which the
exponents' bits are recovered with errors, i.e. where we do not know
a priori which bits are correctly recovered.
The mitigation for the attack is relatively simple - all the bits of
the window are obtained at once, along with other bits so that an
entire integer's worth of bits are obtained together using masking and
shifts, without unnecessarily considering each bit in isolation. This
improves performance somewhat (one call to bn_get_bits is faster than
several calls to BN_is_bit_set), so the attacker now gets one signal
snippet per window (rather than one per bit) in which the signal is
affected by all bits in the integer (rather than just the one bit).
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6276)
The exponent here is one of d, dmp1, or dmq1 for RSA. This value and its
bit length are both secret. The only public upper bound is the bit width
of the corresponding modulus (RSA n, p, and q, respectively).
Although BN_num_bits is constant-time (sort of; see bn_correct_top notes
in preceding patch), this does not fix the root problem, which is that
the windows are based on the minimal bit width, not the upper bound. We
could use BN_num_bits(m), but BN_mod_exp_mont_consttime is public API
and may be called with larger exponents. Instead, use all top*BN_BITS2
bits in the BIGNUM. This is still sensitive to the long-standing
bn_correct_top leak, but we need to fix that regardless.
This may cause us to do a handful of extra multiplications for RSA keys
which are just above a whole number of words, but that is not a standard
RSA key size.
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5154)
All exponentiation subroutines but BN_mod_exp_mont_consttime produce
non-negative result for negative input, which is confusing for fuzzer.
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/4676)
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)
RSA_setup_blinding() calls BN_BLINDING_create_param() which later calls
BN_mod_exp() as follows:
BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx)
ret->mod will have BN_FLG_CONSTTIME set, but ret->e does not. In
BN_mod_exp() we only test the third param for the existence of this flag.
We should test all the inputs.
Thanks to Samuel Weiser (samuel.weiser@iaik.tugraz.at) for reporting this
issue.
This typically only happens once at key load, so this is unlikely to be
exploitable in any real scenario.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4477)
To make it consistent in the code base
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/3749)
Factorise multiple bn_get_top(group->field) calls
Add missing checks on some conditional BN_copy return value
Add missing checks on some BN_copy return value
Add missing checks on a few bn_wexpand return value
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1626)
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1264)
At the same time remove miniscule bias in final subtraction.
Performance penalty varies from platform to platform, and even with
key length. For rsa2048 sign it was observed to be 4% for Sandy
Bridge and 7% on Broadwell.
CVE-2016-0702
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Performance penalty varies from platform to platform, and even
key length. For rsa2048 sign it was observed to reach almost 10%.
CVE-2016-0702
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@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: Viktor Dukhovni <viktor@openssl.org>
Some URLs in the source code ended up getting mangled by indent. This fixes
it. Based on a patch supplied by Arnaud Lacombe <al@aerilon.ca>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Commit 2b0180c37f attempted to do this but
only hit one of many BN_mod_exp codepaths. Fix remaining variants and add
a test for each method.
Thanks to Hanno Boeck for reporting this issue.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
Don't dereference |d| when |top| is zero. Also test that various BIGNUM methods behave correctly on zero/even inputs.
Follow-up to b11980d79a
Reviewed-by: Rich Salz <rsalz@openssl.org>
A small rearrangement so the inclusion of rsaz_exp.h would be
unconditional, but what that header defines becomes conditional.
This solves the weirdness where rsaz_exp.h gets in and out of the
dependency list for bn_exp.c, depending on the present architecture.
Reviewed-by: Rich Salz <rsalz@openssl.org>
There are header files in crypto/ that are used by a number of crypto/
submodules. Move those to crypto/include/internal and adapt the
affected source code and Makefiles.
The header files that got moved are:
crypto/cryptolib.h
crypto/md32_common.h
Reviewed-by: Rich Salz <rsalz@openssl.org>
This gets BN_.*free:
BN_BLINDING_free BN_CTX_free BN_FLG_FREE BN_GENCB_free
BN_MONT_CTX_free BN_RECP_CTX_free BN_clear_free BN_free BUF_MEM_free
Also fix a call to DSA_SIG_free to ccgost engine and remove some #ifdef'd
dead code in engines/e_ubsec.
Reviewed-by: Richard Levitte <levitte@openssl.org>
In the event of an error |rr| could be NULL. Therefore don't assume you can
use |rr| in the error handling code.
Reviewed-by: Andy Polyakov <appro@openssl.org>
