This reverts commit ecc8bc81f2
("crypto: aegis128 - provide a SIMD implementation based on NEON
intrinsics") and commit 7cdc0ddbf7
("crypto: aegis128 - add support for SIMD acceleration").
They cause compile errors on platforms other than ARM because
the mechanism to selectively compile the SIMD code is broken.
Repoted-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To help avoid confusion, add a comment to ghash-generic.c which explains
the convention that the kernel's implementation of GHASH uses.
Also update the Kconfig help text and module descriptions to call GHASH
a "hash function" rather than a "message digest", since the latter
normally means a real cryptographic hash function, which GHASH is not.
Cc: Pascal Van Leeuwen <pvanleeuwen@verimatrix.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Pascal Van Leeuwen <pvanleeuwen@verimatrix.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Provide an accelerated implementation of aegis128 by wiring up the
SIMD hooks in the generic driver to an implementation based on NEON
intrinsics, which can be compiled to both ARM and arm64 code.
This results in a performance of 2.2 cycles per byte on Cortex-A53,
which is a performance increase of ~11x compared to the generic
code.
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Three variants of AEGIS were proposed for the CAESAR competition, and
only one was selected for the final portfolio: AEGIS128.
The other variants, AEGIS128L and AEGIS256, are not likely to ever turn
up in networking protocols or other places where interoperability
between Linux and other systems is a concern, nor are they likely to
be subjected to further cryptanalysis. However, uninformed users may
think that AEGIS128L (which is faster) is equally fit for use.
So let's remove them now, before anyone starts using them and we are
forced to support them forever.
Note that there are no known flaws in the algorithms or in any of these
implementations, but they have simply outlived their usefulness.
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
MORUS was not selected as a winner in the CAESAR competition, which
is not surprising since it is considered to be cryptographically
broken [0]. (Note that this is not an implementation defect, but a
flaw in the underlying algorithm). Since it is unlikely to be in use
currently, let's remove it before we're stuck with it.
[0] https://eprint.iacr.org/2019/172.pdf
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Drop aes-generic's version of crypto_aes_expand_key(), and switch to
the key expansion routine provided by the AES library. AES key expansion
is not performance critical, and it is better to have a single version
shared by all AES implementations.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The AES assembler code for x86 isn't actually faster than code
generated by the compiler from aes_generic.c, and considering
the disproportionate maintenance burden of assembler code on
x86, it is better just to drop it entirely. Modern x86 systems
will use AES-NI anyway, and given that the modules being removed
have a dependency on aes_generic already, we can remove them
without running the risk of regressions.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The AES-NI code contains fallbacks for invocations that occur from a
context where the SIMD unit is unavailable, which really only occurs
when running in softirq context that was entered from a hard IRQ that
was taken while running kernel code that was already using the FPU.
That means performance is not really a consideration, and we can just
use the new library code for this use case, which has a smaller
footprint and is believed to be time invariant. This will allow us to
drop the non-SIMD asm routines in a subsequent patch.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Take the existing small footprint and mostly time invariant C code
and turn it into a AES library that can be used for non-performance
critical, casual use of AES, and as a fallback for, e.g., SIMD code
that needs a secondary path that can be taken in contexts where the
SIMD unit is off limits (e.g., in hard interrupts taken from kernel
context)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Refactor the core rc4 handling so we can move most users to a library
interface, permitting us to drop the cipher interface entirely in a
future patch. This is part of an effort to simplify the crypto API
and improve its robustness against incorrect use.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
xxhash is currently implemented as a self-contained module in /lib.
This patch enables that module to be used as part of the generic kernel
crypto framework. It adds a simple wrapper to the 64bit version.
I've also added test vectors (with help from Nick Terrell). The upstream
xxhash code is tested by running hashing operation on random 222 byte
data with seed values of 0 and a prime number. The upstream test
suite can be found at https://github.com/Cyan4973/xxHash/blob/cf46e0c/xxhsum.c#L664
Essentially hashing is run on data of length 0,1,14,222 with the
aforementioned seed values 0 and prime 2654435761. The particular random
222 byte string was provided to me by Nick Terrell by reading
/dev/random and the checksums were calculated by the upstream xxsum
utility with the following bash script:
dd if=/dev/random of=TEST_VECTOR bs=1 count=222
for a in 0 1; do
for l in 0 1 14 222; do
for s in 0 2654435761; do
echo algo $a length $l seed $s;
head -c $l TEST_VECTOR | ~/projects/kernel/xxHash/xxhsum -H$a -s$s
done
done
done
This produces output as follows:
algo 0 length 0 seed 0
02cc5d05 stdin
algo 0 length 0 seed 2654435761
02cc5d05 stdin
algo 0 length 1 seed 0
25201171 stdin
algo 0 length 1 seed 2654435761
25201171 stdin
algo 0 length 14 seed 0
c1d95975 stdin
algo 0 length 14 seed 2654435761
c1d95975 stdin
algo 0 length 222 seed 0
b38662a6 stdin
algo 0 length 222 seed 2654435761
b38662a6 stdin
algo 1 length 0 seed 0
ef46db3751d8e999 stdin
algo 1 length 0 seed 2654435761
ac75fda2929b17ef stdin
algo 1 length 1 seed 0
27c3f04c2881203a stdin
algo 1 length 1 seed 2654435761
4a15ed26415dfe4d stdin
algo 1 length 14 seed 0
3d33dc700231dfad stdin
algo 1 length 14 seed 2654435761
ea5f7ddef9a64f80 stdin
algo 1 length 222 seed 0
5f3d3c08ec2bef34 stdin
algo 1 length 222 seed 2654435761
6a9df59664c7ed62 stdin
algo 1 is xx64 variant, algo 0 is the 32 bit variant which is currently
not hooked up.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
kcrypto_wq is only used by cryptd, so move it into cryptd.c and change
the workqueue name from "crypto" to "cryptd".
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
There's no reason for users to select CONFIG_CRYPTO_GF128MUL, since it's
just some helper functions, and algorithms that need it select it.
Remove the prompt string so that it's not shown to users.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
echainiv is the only algorithm or template in the crypto API that is
enabled by default. But there doesn't seem to be a good reason for it.
And it pulls in a lot of stuff as dependencies, like AEAD support and a
"NIST SP800-90A DRBG" including HMAC-SHA256.
The commit which made it default 'm', commit 3491244c62 ("crypto:
echainiv - Set Kconfig default to m"), mentioned that it's needed for
IPsec. However, later commit 32b6170ca5 ("ipv4+ipv6: Make INET*_ESP
select CRYPTO_ECHAINIV") made the IPsec kconfig options select it.
So, remove the 'default m'.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The "cryptomgr" module is required for templates to be used. Many
templates select it, but others don't. Make all templates select it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The crypto self-tests are part of the "cryptomgr" module, which can
technically be disabled (though it rarely is). If you do so, currently
you can still enable CRYPTO_MANAGER_EXTRA_TESTS, which doesn't make
sense since in that case testmgr.c isn't compiled at all. Fix it by
making it CRYPTO_MANAGER_EXTRA_TESTS depend on CRYPTO_MANAGER2, like
CRYPTO_MANAGER_DISABLE_TESTS already does.
Fixes: 5b2706a4d4 ("crypto: testmgr - introduce CONFIG_CRYPTO_MANAGER_EXTRA_TESTS")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix undefined symbol issue in ecrdsa_generic module when ASN1
or OID_REGISTRY aren't enabled in the config by selecting these
options for CRYPTO_ECRDSA.
ERROR: "asn1_ber_decoder" [crypto/ecrdsa_generic.ko] undefined!
ERROR: "look_up_OID" [crypto/ecrdsa_generic.ko] undefined!
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add Elliptic Curve Russian Digital Signature Algorithm (GOST R
34.10-2012, RFC 7091, ISO/IEC 14888-3) is one of the Russian (and since
2018 the CIS countries) cryptographic standard algorithms (called GOST
algorithms). Only signature verification is supported, with intent to be
used in the IMA.
Summary of the changes:
* crypto/Kconfig:
- EC-RDSA is added into Public-key cryptography section.
* crypto/Makefile:
- ecrdsa objects are added.
* crypto/asymmetric_keys/x509_cert_parser.c:
- Recognize EC-RDSA and Streebog OIDs.
* include/linux/oid_registry.h:
- EC-RDSA OIDs are added to the enum. Also, a two currently not
implemented curve OIDs are added for possible extension later (to
not change numbering and grouping).
* crypto/ecc.c:
- Kenneth MacKay copyright date is updated to 2014, because
vli_mmod_slow, ecc_point_add, ecc_point_mult_shamir are based on his
code from micro-ecc.
- Functions needed for ecrdsa are EXPORT_SYMBOL'ed.
- New functions:
vli_is_negative - helper to determine sign of vli;
vli_from_be64 - unpack big-endian array into vli (used for
a signature);
vli_from_le64 - unpack little-endian array into vli (used for
a public key);
vli_uadd, vli_usub - add/sub u64 value to/from vli (used for
increment/decrement);
mul_64_64 - optimized to use __int128 where appropriate, this speeds
up point multiplication (and as a consequence signature
verification) by the factor of 1.5-2;
vli_umult - multiply vli by a small value (speeds up point
multiplication by another factor of 1.5-2, depending on vli sizes);
vli_mmod_special - module reduction for some form of Pseudo-Mersenne
primes (used for the curves A);
vli_mmod_special2 - module reduction for another form of
Pseudo-Mersenne primes (used for the curves B);
vli_mmod_barrett - module reduction using pre-computed value (used
for the curve C);
vli_mmod_slow - more general module reduction which is much slower
(used when the modulus is subgroup order);
vli_mod_mult_slow - modular multiplication;
ecc_point_add - add two points;
ecc_point_mult_shamir - add two points multiplied by scalars in one
combined multiplication (this gives speed up by another factor 2 in
compare to two separate multiplications).
ecc_is_pubkey_valid_partial - additional samity check is added.
- Updated vli_mmod_fast with non-strict heuristic to call optimal
module reduction function depending on the prime value;
- All computations for the previously defined (two NIST) curves should
not unaffected.
* crypto/ecc.h:
- Newly exported functions are documented.
* crypto/ecrdsa_defs.h
- Five curves are defined.
* crypto/ecrdsa.c:
- Signature verification is implemented.
* crypto/ecrdsa_params.asn1, crypto/ecrdsa_pub_key.asn1:
- Templates for BER decoder for EC-RDSA parameters and public key.
Cc: linux-integrity@vger.kernel.org
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
ecc.c have algorithms that could be used togeter by ecdh and ecrdsa.
Make it separate module. Add CRYPTO_ECC into Kconfig. EXPORT_SYMBOL and
document to what seems appropriate. Move structs ecc_point and ecc_curve
from ecc_curve_defs.h into ecc.h.
No code changes.
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Group RSA, DH, and ECDH into Public-key cryptography config section.
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Spotted while reviewind patches from Eric Biggers.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Convert the x86 implementations of MORUS-1280 to use the AEAD SIMD
helpers, rather than hand-rolling the same functionality. This
simplifies the code and also fixes the bug where the user-provided
aead_request is modified.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Convert the x86 implementation of MORUS-640 to use the AEAD SIMD
helpers, rather than hand-rolling the same functionality. This
simplifies the code and also fixes the bug where the user-provided
aead_request is modified.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Convert the x86 implementation of AEGIS-256 to use the AEAD SIMD
helpers, rather than hand-rolling the same functionality. This
simplifies the code and also fixes the bug where the user-provided
aead_request is modified.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Convert the x86 implementation of AEGIS-128L to use the AEAD SIMD
helpers, rather than hand-rolling the same functionality. This
simplifies the code and also fixes the bug where the user-provided
aead_request is modified.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Convert the x86 implementation of AEGIS-128 to use the AEAD SIMD
helpers, rather than hand-rolling the same functionality. This
simplifies the code and also fixes the bug where the user-provided
aead_request is modified.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To achieve more comprehensive crypto test coverage, I'd like to add fuzz
tests that use random data layouts and request flags.
To be most effective these tests should be part of testmgr, so they
automatically run on every algorithm registered with the crypto API.
However, they will take much longer to run than the current tests and
therefore will only really be intended to be run by developers, whereas
the current tests have a wider audience.
Therefore, add a new kconfig option CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
that can be set by developers to enable these extra, expensive tests.
Similar to the regular tests, also add a module parameter
cryptomgr.noextratests to support disabling the tests.
Finally, another module parameter cryptomgr.fuzz_iterations is added to
control how many iterations the fuzz tests do. Note: for now setting
this to 0 will be equivalent to cryptomgr.noextratests=1. But I opted
for separate parameters to provide more flexibility to add other types
of tests under the "extra tests" category in the future.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
- support -y option for merge_config.sh to avoid downgrading =y to =m
- remove S_OTHER symbol type, and touch include/config/*.h files correctly
- fix file name and line number in lexer warnings
- fix memory leak when EOF is encountered in quotation
- resolve all shift/reduce conflicts of the parser
- warn no new line at end of file
- make 'source' statement more strict to take only string literal
- rewrite the lexer and remove the keyword lookup table
- convert to SPDX License Identifier
- compile C files independently instead of including them from zconf.y
- fix various warnings of gconfig
- misc cleanups
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Merge tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kconfig updates from Masahiro Yamada:
- support -y option for merge_config.sh to avoid downgrading =y to =m
- remove S_OTHER symbol type, and touch include/config/*.h files correctly
- fix file name and line number in lexer warnings
- fix memory leak when EOF is encountered in quotation
- resolve all shift/reduce conflicts of the parser
- warn no new line at end of file
- make 'source' statement more strict to take only string literal
- rewrite the lexer and remove the keyword lookup table
- convert to SPDX License Identifier
- compile C files independently instead of including them from zconf.y
- fix various warnings of gconfig
- misc cleanups
* tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
kconfig: surround dbg_sym_flags with #ifdef DEBUG to fix gconf warning
kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings
kconfig: add static qualifiers to fix gconf warnings
kconfig: split the lexer out of zconf.y
kconfig: split some C files out of zconf.y
kconfig: convert to SPDX License Identifier
kconfig: remove keyword lookup table entirely
kconfig: update current_pos in the second lexer
kconfig: switch to ASSIGN_VAL state in the second lexer
kconfig: stop associating kconf_id with yylval
kconfig: refactor end token rules
kconfig: stop supporting '.' and '/' in unquoted words
treewide: surround Kconfig file paths with double quotes
microblaze: surround string default in Kconfig with double quotes
kconfig: use T_WORD instead of T_VARIABLE for variables
kconfig: use specific tokens instead of T_ASSIGN for assignments
kconfig: refactor scanning and parsing "option" properties
kconfig: use distinct tokens for type and default properties
kconfig: remove redundant token defines
kconfig: rename depends_list to comment_option_list
...
The Kconfig lexer supports special characters such as '.' and '/' in
the parameter context. In my understanding, the reason is just to
support bare file paths in the source statement.
I do not see a good reason to complicate Kconfig for the room of
ambiguity.
The majority of code already surrounds file paths with double quotes,
and it makes sense since file paths are constant string literals.
Make it treewide consistent now.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Now that the x86_64 SIMD implementations of ChaCha20 and XChaCha20 have
been refactored to support varying the number of rounds, add support for
XChaCha12. This is identical to XChaCha20 except for the number of
rounds, which is 12 instead of 20. This can be used by Adiantum.
Reviewed-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add an XChaCha20 implementation that is hooked up to the x86_64 SIMD
implementations of ChaCha20. This can be used by Adiantum.
An SSSE3 implementation of single-block HChaCha20 is also added so that
XChaCha20 can use it rather than the generic implementation. This
required refactoring the ChaCha permutation into its own function.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a 64-bit AVX2 implementation of NHPoly1305, an ε-almost-∆-universal
hash function used in the Adiantum encryption mode. For now, only the
NH portion is actually AVX2-accelerated; the Poly1305 part is less
performance-critical so is just implemented in C.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a 64-bit SSE2 implementation of NHPoly1305, an ε-almost-∆-universal
hash function used in the Adiantum encryption mode. For now, only the
NH portion is actually SSE2-accelerated; the Poly1305 part is less
performance-critical so is just implemented in C.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
CRYPTO_STATS is using CRYPTO_USER stuff, so it should depends on it.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add support for the Adiantum encryption mode. Adiantum was designed by
Paul Crowley and is specified by our paper:
Adiantum: length-preserving encryption for entry-level processors
(https://eprint.iacr.org/2018/720.pdf)
See our paper for full details; this patch only provides an overview.
Adiantum is a tweakable, length-preserving encryption mode designed for
fast and secure disk encryption, especially on CPUs without dedicated
crypto instructions. Adiantum encrypts each sector using the XChaCha12
stream cipher, two passes of an ε-almost-∆-universal (εA∆U) hash
function, and an invocation of the AES-256 block cipher on a single
16-byte block. On CPUs without AES instructions, Adiantum is much
faster than AES-XTS; for example, on ARM Cortex-A7, on 4096-byte sectors
Adiantum encryption is about 4 times faster than AES-256-XTS encryption,
and decryption about 5 times faster.
Adiantum is a specialization of the more general HBSH construction. Our
earlier proposal, HPolyC, was also a HBSH specialization, but it used a
different εA∆U hash function, one based on Poly1305 only. Adiantum's
εA∆U hash function, which is based primarily on the "NH" hash function
like that used in UMAC (RFC4418), is about twice as fast as HPolyC's;
consequently, Adiantum is about 20% faster than HPolyC.
This speed comes with no loss of security: Adiantum is provably just as
secure as HPolyC, in fact slightly *more* secure. Like HPolyC,
Adiantum's security is reducible to that of XChaCha12 and AES-256,
subject to a security bound. XChaCha12 itself has a security reduction
to ChaCha12. Therefore, one need not "trust" Adiantum; one need only
trust ChaCha12 and AES-256. Note that the εA∆U hash function is only
used for its proven combinatorical properties so cannot be "broken".
Adiantum is also a true wide-block encryption mode, so flipping any
plaintext bit in the sector scrambles the entire ciphertext, and vice
versa. No other such mode is available in the kernel currently; doing
the same with XTS scrambles only 16 bytes. Adiantum also supports
arbitrary-length tweaks and naturally supports any length input >= 16
bytes without needing "ciphertext stealing".
For the stream cipher, Adiantum uses XChaCha12 rather than XChaCha20 in
order to make encryption feasible on the widest range of devices.
Although the 20-round variant is quite popular, the best known attacks
on ChaCha are on only 7 rounds, so ChaCha12 still has a substantial
security margin; in fact, larger than AES-256's. 12-round Salsa20 is
also the eSTREAM recommendation. For the block cipher, Adiantum uses
AES-256, despite it having a lower security margin than XChaCha12 and
needing table lookups, due to AES's extensive adoption and analysis
making it the obvious first choice. Nevertheless, for flexibility this
patch also permits the "adiantum" template to be instantiated with
XChaCha20 and/or with an alternate block cipher.
We need Adiantum support in the kernel for use in dm-crypt and fscrypt,
where currently the only other suitable options are block cipher modes
such as AES-XTS. A big problem with this is that many low-end mobile
devices (e.g. Android Go phones sold primarily in developing countries,
as well as some smartwatches) still have CPUs that lack AES
instructions, e.g. ARM Cortex-A7. Sadly, AES-XTS encryption is much too
slow to be viable on these devices. We did find that some "lightweight"
block ciphers are fast enough, but these suffer from problems such as
not having much cryptanalysis or being too controversial.
The ChaCha stream cipher has excellent performance but is insecure to
use directly for disk encryption, since each sector's IV is reused each
time it is overwritten. Even restricting the threat model to offline
attacks only isn't enough, since modern flash storage devices don't
guarantee that "overwrites" are really overwrites, due to wear-leveling.
Adiantum avoids this problem by constructing a
"tweakable super-pseudorandom permutation"; this is the strongest
possible security model for length-preserving encryption.
Of course, storing random nonces along with the ciphertext would be the
ideal solution. But doing that with existing hardware and filesystems
runs into major practical problems; in most cases it would require data
journaling (like dm-integrity) which severely degrades performance.
Thus, for now length-preserving encryption is still needed.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a generic implementation of NHPoly1305, an ε-almost-∆-universal hash
function used in the Adiantum encryption mode.
CONFIG_NHPOLY1305 is not selectable by itself since there won't be any
real reason to enable it without also enabling Adiantum support.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that the generic implementation of ChaCha20 has been refactored to
allow varying the number of rounds, add support for XChaCha12, which is
the XSalsa construction applied to ChaCha12. ChaCha12 is one of the
three ciphers specified by the original ChaCha paper
(https://cr.yp.to/chacha/chacha-20080128.pdf: "ChaCha, a variant of
Salsa20"), alongside ChaCha8 and ChaCha20. ChaCha12 is faster than
ChaCha20 but has a lower, but still large, security margin.
We need XChaCha12 support so that it can be used in the Adiantum
encryption mode, which enables disk/file encryption on low-end mobile
devices where AES-XTS is too slow as the CPUs lack AES instructions.
We'd prefer XChaCha20 (the more popular variant), but it's too slow on
some of our target devices, so at least in some cases we do need the
XChaCha12-based version. In more detail, the problem is that Adiantum
is still much slower than we're happy with, and encryption still has a
quite noticeable effect on the feel of low-end devices. Users and
vendors push back hard against encryption that degrades the user
experience, which always risks encryption being disabled entirely. So
we need to choose the fastest option that gives us a solid margin of
security, and here that's XChaCha12. The best known attack on ChaCha
breaks only 7 rounds and has 2^235 time complexity, so ChaCha12's
security margin is still better than AES-256's. Much has been learned
about cryptanalysis of ARX ciphers since Salsa20 was originally designed
in 2005, and it now seems we can be comfortable with a smaller number of
rounds. The eSTREAM project also suggests the 12-round version of
Salsa20 as providing the best balance among the different variants:
combining very good performance with a "comfortable margin of security".
Note that it would be trivial to add vanilla ChaCha12 in addition to
XChaCha12. However, it's unneeded for now and therefore is omitted.
As discussed in the patch that introduced XChaCha20 support, I
considered splitting the code into separate chacha-common, chacha20,
xchacha20, and xchacha12 modules, so that these algorithms could be
enabled/disabled independently. However, since nearly all the code is
shared anyway, I ultimately decided there would have been little benefit
to the added complexity.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add support for the XChaCha20 stream cipher. XChaCha20 is the
application of the XSalsa20 construction
(https://cr.yp.to/snuffle/xsalsa-20081128.pdf) to ChaCha20 rather than
to Salsa20. XChaCha20 extends ChaCha20's nonce length from 64 bits (or
96 bits, depending on convention) to 192 bits, while provably retaining
ChaCha20's security. XChaCha20 uses the ChaCha20 permutation to map the
key and first 128 nonce bits to a 256-bit subkey. Then, it does the
ChaCha20 stream cipher with the subkey and remaining 64 bits of nonce.
We need XChaCha support in order to add support for the Adiantum
encryption mode. Note that to meet our performance requirements, we
actually plan to primarily use the variant XChaCha12. But we believe
it's wise to first add XChaCha20 as a baseline with a higher security
margin, in case there are any situations where it can be used.
Supporting both variants is straightforward.
Since XChaCha20's subkey differs for each request, XChaCha20 can't be a
template that wraps ChaCha20; that would require re-keying the
underlying ChaCha20 for every request, which wouldn't be thread-safe.
Instead, we make XChaCha20 its own top-level algorithm which calls the
ChaCha20 streaming implementation internally.
Similar to the existing ChaCha20 implementation, we define the IV to be
the nonce and stream position concatenated together. This allows users
to seek to any position in the stream.
I considered splitting the code into separate chacha20-common, chacha20,
and xchacha20 modules, so that chacha20 and xchacha20 could be
enabled/disabled independently. However, since nearly all the code is
shared anyway, I ultimately decided there would have been little benefit
to the added complexity of separate modules.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
cts(cbc(aes)) as used in the kernel has been added to NIST
standard as CBC-CS3. Document it as such.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Suggested-by: Stephan Mueller <smueller@chronox.de>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In the "aes-fixed-time" AES implementation, disable interrupts while
accessing the S-box, in order to make cache-timing attacks more
difficult. Previously it was possible for the CPU to be interrupted
while the S-box was loaded into L1 cache, potentially evicting the
cachelines and causing later table lookups to be time-variant.
In tests I did on x86 and ARM, this doesn't affect performance
significantly. Responsiveness is potentially a concern, but interrupts
are only disabled for a single AES block.
Note that even after this change, the implementation still isn't
necessarily guaranteed to be constant-time; see
https://cr.yp.to/antiforgery/cachetiming-20050414.pdf for a discussion
of the many difficulties involved in writing truly constant-time AES
software. But it's valuable to make such attacks more difficult.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
For historical reasons, the AES-NI based implementation of the PCBC
chaining mode uses a special FPU chaining mode wrapper template to
amortize the FPU start/stop overhead over multiple blocks.
When this FPU wrapper was introduced, it supported widely used
chaining modes such as XTS and CTR (as well as LRW), but currently,
PCBC is the only remaining user.
Since there are no known users of pcbc(aes) in the kernel, let's remove
this special driver, and rely on the generic pcbc driver to encapsulate
the AES-NI core cipher.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a generic version of output feedback mode. We already have support of
several hardware based transformations of this mode and the needed test
vectors but we somehow missed adding a generic software one. Fix this now.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch implement a generic way to get statistics about all crypto
usages.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As it turns out, the AVX2 multibuffer SHA routines are currently
broken [0], in a way that would have likely been noticed if this
code were in wide use. Since the code is too complicated to be
maintained by anyone except the original authors, and since the
performance benefits for real-world use cases are debatable to
begin with, it is better to drop it entirely for the moment.
[0] https://marc.info/?l=linux-crypto-vger&m=153476243825350&w=2
Suggested-by: Eric Biggers <ebiggers@google.com>
Cc: Megha Dey <megha.dey@linux.intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
These are unused, undesired, and have never actually been used by
anybody. The original authors of this code have changed their mind about
its inclusion. While originally proposed for disk encryption on low-end
devices, the idea was discarded [1] in favor of something else before
that could really get going. Therefore, this patch removes Speck.
[1] https://marc.info/?l=linux-crypto-vger&m=153359499015659
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Eric Biggers <ebiggers@google.com>
Cc: stable@vger.kernel.org
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The x86 assembly implementations of Salsa20 use the frame base pointer
register (%ebp or %rbp), which breaks frame pointer convention and
breaks stack traces when unwinding from an interrupt in the crypto code.
Recent (v4.10+) kernels will warn about this, e.g.
WARNING: kernel stack regs at 00000000a8291e69 in syzkaller047086:4677 has bad 'bp' value 000000001077994c
[...]
But after looking into it, I believe there's very little reason to still
retain the x86 Salsa20 code. First, these are *not* vectorized
(SSE2/SSSE3/AVX2) implementations, which would be needed to get anywhere
close to the best Salsa20 performance on any remotely modern x86
processor; they're just regular x86 assembly. Second, it's still
unclear that anyone is actually using the kernel's Salsa20 at all,
especially given that now ChaCha20 is supported too, and with much more
efficient SSSE3 and AVX2 implementations. Finally, in benchmarks I did
on both Intel and AMD processors with both gcc 8.1.0 and gcc 4.9.4, the
x86_64 salsa20-asm is actually slightly *slower* than salsa20-generic
(~3% slower on Skylake, ~10% slower on Zen), while the i686 salsa20-asm
is only slightly faster than salsa20-generic (~15% faster on Skylake,
~20% faster on Zen). The gcc version made little difference.
So, the x86_64 salsa20-asm is pretty clearly useless. That leaves just
the i686 salsa20-asm, which based on my tests provides a 15-20% speed
boost. But that's without updating the code to not use %ebp. And given
the maintenance cost, the small speed difference vs. salsa20-generic,
the fact that few people still use i686 kernels, the doubt that anyone
is even using the kernel's Salsa20 at all, and the fact that a SSE2
implementation would almost certainly be much faster on any remotely
modern x86 processor yet no one has cared enough to add one yet, I don't
think it's worthwhile to keep.
Thus, just remove both the x86_64 and i686 salsa20-asm implementations.
Reported-by: syzbot+ffa3a158337bbc01ff09@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Commit 56e8e57fc3 ("crypto: morus - Add common SIMD glue code for
MORUS") accidetally consiedered the glue code to be usable by different
architectures, but it seems to be only usable on x86.
This patch moves it under arch/x86/crypto and adds 'depends on X86' to
the Kconfig options and also removes the prompt to hide these internal
options from the user.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Herbert Xu