Commit Graph

14 Commits

Author SHA1 Message Date
Vitaly Chikunov
0d7a78643f crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm
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>
2019-04-18 22:15:02 +08:00
Vitaly Chikunov
4a2289dae0 crypto: ecc - make ecc into separate module
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>
2019-04-18 22:15:02 +08:00
Vitaly Chikunov
3da2c1dfdb crypto: ecc - regularize scalar for scalar multiplication
ecc_point_mult is supposed to be used with a regularized scalar,
otherwise, it's possible to deduce the position of the top bit of the
scalar with timing attack. This is important when the scalar is a
private key.

ecc_point_mult is already using a regular algorithm (i.e. having an
operation flow independent of the input scalar) but regularization step
is not implemented.

Arrange scalar to always have fixed top bit by adding a multiple of the
curve order (n).

References:
The constant time regularization step is based on micro-ecc by Kenneth
MacKay and also referenced in the literature (Bernstein, D. J., & Lange,
T. (2017). Montgomery curves and the Montgomery ladder. (Cryptology
ePrint Archive; Vol. 2017/293). s.l.: IACR. Chapter 4.6.2.)

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Cc: kernel-hardening@lists.openwall.com
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-11-16 14:11:04 +08:00
Vitaly Chikunov
2eb4942b66 crypto: ecc - check for invalid values in the key verification test
Currently used scalar multiplication algorithm (Matthieu Rivain, 2011)
have invalid values for scalar == 1, n-1, and for regularized version
n-2, which was previously not checked. Verify that they are not used as
private keys.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-11-16 14:09:39 +08:00
Stephan Mueller
ea169a30a6 crypto: ecdh - add public key verification test
According to SP800-56A section 5.6.2.1, the public key to be processed
for the ECDH operation shall be checked for appropriateness. When the
public key is considered to be an ephemeral key, the partial validation
test as defined in SP800-56A section 5.6.2.3.4 can be applied.

The partial verification test requires the presence of the field
elements of a and b. For the implemented NIST curves, b is defined in
FIPS 186-4 appendix D.1.2. The element a is implicitly given with the
Weierstrass equation given in D.1.2 where a = p - 3.

Without the test, the NIST ACVP testing fails. After adding this check,
the NIST ACVP testing passes.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-07-09 00:26:19 +08:00
Kees Cook
d5c3b17898 crypto: ecc - Actually remove stack VLA usage
On the quest to remove all VLAs from the kernel[1], this avoids VLAs
by just using the maximum allocation size (4 bytes) for stack arrays.
All the VLAs in ecc were either 3 or 4 bytes (or a multiple), so just
make it 4 bytes all the time. Initialization routines are adjusted to
check that ndigits does not end up larger than the arrays.

This includes a removal of the earlier attempt at this fix from
commit a963834b4742 ("crypto/ecc: Remove stack VLA usage")

[1] https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-04-21 00:58:29 +08:00
Kees Cook
14de52112e crypto: ecc - Remove stack VLA usage
On the quest to remove all VLAs from the kernel[1], this switches to
a pair of kmalloc regions instead of using the stack. This also moves
the get_random_bytes() after all allocations (and drops the needless
"nbytes" variable).

[1] https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-03-16 23:35:53 +08:00
Pierre
4c0e22c905 crypto: ecc - Fix NULL pointer deref. on no default_rng
If crypto_get_default_rng returns an error, the
function ecc_gen_privkey should return an error.
Instead, it currently tries to use the default_rng
nevertheless, thus creating a kernel panic with a
NULL pointer dereference.
Returning the error directly, as was supposedly
intended when looking at the code, fixes this.

Signed-off-by: Pierre Ducroquet <pinaraf@pinaraf.info>
Reviewed-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29 17:33:24 +11:00
Tudor-Dan Ambarus
6755fd269d crypto: ecdh - add privkey generation support
Add support for generating ecc private keys.

Generation of ecc private keys is helpful in a user-space to kernel
ecdh offload because the keys are not revealed to user-space. Private
key generation is also helpful to implement forward secrecy.

If the user provides a NULL ecc private key, the kernel will generate it
and further use it for ecdh.

Move ecdh's object files below drbg's. drbg must be present in the kernel
at the time of calling.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-06-10 12:04:35 +08:00
Tudor-Dan Ambarus
7380c56d2f crypto: ecc - rename ecdh_make_pub_key()
Rename ecdh_make_pub_key() to ecc_make_pub_key().
ecdh_make_pub_key() is not dh specific and the reference
to dh is wrong.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-06-10 12:04:26 +08:00
Tudor-Dan Ambarus
ad26959710 crypto: ecc - remove unnecessary casts
ecc software implementation works with chunks of u64 data. There were some
unnecessary casts to u8 and then back to u64 for the ecc keys. This patch
removes the unnecessary casts.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-06-10 12:04:26 +08:00
Tudor-Dan Ambarus
099054d735 crypto: ecc - remove unused function arguments
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-06-10 12:04:25 +08:00
Stephen Rothwell
8f44df154d crypto: ecdh - make ecdh_shared_secret unique
There is another ecdh_shared_secret in net/bluetooth/ecc.c

Fixes: 3c4b23901a ("crypto: ecdh - Add ECDH software support")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-06-24 21:24:59 +08:00
Salvatore Benedetto
3c4b23901a crypto: ecdh - Add ECDH software support
* Implement ECDH under kpp API
 * Provide ECC software support for curve P-192 and
   P-256.
 * Add kpp test for ECDH with data generated by OpenSSL

Signed-off-by: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-06-23 18:29:57 +08:00