Commit Graph

40 Commits

Author SHA1 Message Date
Stefan Berger
1dcf865d3b crypto: ecc - Fix off-by-one missing to clear most significant digit
Fix an off-by-one error where the most significant digit was not
initialized leading to signature verification failures by the testmgr.

Example: If a curve requires ndigits (=9) and diff (=2) indicates that
2 digits need to be set to zero then start with digit 'ndigits - diff' (=7)
and clear 'diff' digits starting from there, so 7 and 8.

Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
Closes: https://lore.kernel.org/linux-crypto/619bc2de-b18a-4939-a652-9ca886bf6349@linux.ibm.com/T/#m045d8812409ce233c17fcdb8b88b6629c671f9f4
Fixes: 2fd2a82ccb ("crypto: ecdsa - Use ecc_digits_from_bytes to create hash digits array")
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-06-16 13:41:53 +08:00
Jeff Johnson
7c699fe9a5 crypto: Add missing MODULE_DESCRIPTION() macros
Fix the 'make W=1' warnings:
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/cast_common.o
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/af_alg.o
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/algif_hash.o
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/algif_skcipher.o
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/ecc.o
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/curve25519-generic.o
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/xor.o
WARNING: modpost: missing MODULE_DESCRIPTION() in crypto/crypto_simd.o

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-05-31 17:34:56 +08:00
Stefan Berger
c6ab5c915d crypto: ecc - Prevent ecc_digits_from_bytes from reading too many bytes
Prevent ecc_digits_from_bytes from reading too many bytes from the input
byte array in case an insufficient number of bytes is provided to fill the
output digit array of ndigits. Therefore, initialize the most significant
digits with 0 to avoid trying to read too many bytes later on. Convert the
function into a regular function since it is getting too big for an inline
function.

If too many bytes are provided on the input byte array the extra bytes
are ignored since the input variable 'ndigits' limits the number of digits
that will be filled.

Fixes: d67c96fb97 ("crypto: ecdsa - Convert byte arrays with key coordinates to digits")
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-05-17 18:55:07 +08:00
Stefan Berger
01474b70a7 crypto: ecdh - Initialize ctx->private_key in proper byte order
The private key in ctx->private_key is currently initialized in reverse
byte order in ecdh_set_secret and whenever the key is needed in proper
byte order the variable priv is introduced and the bytes from
ctx->private_key are copied into priv while being byte-swapped
(ecc_swap_digits). To get rid of the unnecessary byte swapping initialize
ctx->private_key in proper byte order and clean up all functions that were
previously using priv or were called with ctx->private_key:

- ecc_gen_privkey: Directly initialize the passed ctx->private_key with
  random bytes filling all the digits of the private key. Get rid of the
  priv variable. This function only has ecdh_set_secret as a caller to
  create NIST P192/256/384 private keys.

- crypto_ecdh_shared_secret: Called only from ecdh_compute_value with
  ctx->private_key. Get rid of the priv variable and work with the passed
  private_key directly.

- ecc_make_pub_key: Called only from ecdh_compute_value with
  ctx->private_key. Get rid of the priv variable and work with the passed
  private_key directly.

Cc: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-26 17:26:09 +08:00
Stefan Berger
288b46c57c crypto: ecc - Add NIST P521 curve parameters
Add the parameters for the NIST P521 curve and define a new curve ID
for it. Make the curve available in ecc_get_curve.

Tested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-12 15:07:52 +08:00
Stefan Berger
114e80437e crypto: ecc - Add special case for NIST P521 in ecc_point_mult
In ecc_point_mult use the number of bits of the NIST P521 curve + 2. The
change is required specifically for NIST P521 to pass mathematical tests
on the public key.

Tested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-12 15:07:52 +08:00
Stefan Berger
e7fb062754 crypto: ecc - Implement vli_mmod_fast_521 for NIST p521
Implement vli_mmod_fast_521 following the description for how to calculate
the modulus for NIST P521 in the NIST publication "Recommendations for
Discrete Logarithm-Based Cryptography: Elliptic Curve Domain Parameters"
section G.1.4.

NIST p521 requires 9 64bit digits, so increase the ECC_MAX_DIGITS so that
the vli digit array provides enough elements to fit the larger integers
required by this curve.

Tested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-12 15:07:52 +08:00
Stefan Berger
526d23fc2d crypto: ecc - Use ECC_CURVE_NIST_P192/256/384_DIGITS where possible
Replace hard-coded numbers with ECC_CURVE_NIST_P192/256/384_DIGITS where
possible.

Tested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-12 15:07:51 +08:00
Roman Smirnov
233e750592 crypto: ecc - remove checks in crypto_ecdh_shared_secret() and ecc_make_pub_key()
With the current state of the code, ecc_get_curve() cannot return
NULL in crypto_ecdh_shared_secret() and ecc_make_pub_key(). This is
conditioned by the fact that they are only called from ecdh_compute_value(),
which implements the kpp_alg::{generate_public_key,compute_shared_secret}()
methods. Also ecdh implements the kpp_alg::init() method, which is called
before the other methods and sets ecdh_ctx::curve_id to a valid value.

Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-12 15:07:51 +08:00
Joachim Vandersmissen
dbad7b6969 crypto: ecc - update ecc_gen_privkey for FIPS 186-5
FIPS 186-5 [1] was released approximately 1 year ago. The most
interesting change for ecc_gen_privkey is the removal of curves with
order < 224 bits. This is minimum is now checked in step 1. It is
unlikely that there is still any benefit in generating private keys for
curves with n < 224, as those curves provide less than 112 bits of
security strength and are therefore unsafe for any modern usage.

This patch also updates the documentation for __ecc_is_key_valid and
ecc_gen_privkey to clarify which FIPS 186-5 method is being used to
generate private keys. Previous documentation mentioned that "extra
random bits" was used. However, this did not match the code. Instead,
the code currently uses (and always has used) the "rejection sampling"
("testing candidates" in FIPS 186-4) method.

[1]: https://doi.org/10.6028/NIST.FIPS.186-5

Signed-off-by: Joachim Vandersmissen <git@jvdsn.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-02 10:49:38 +08:00
Herbert Xu
5072b1c211 crypto: ecc - Silence sparse warning
Rewrite the bitwise operations to silence the sparse warnings:

  CHECK   ../crypto/ecc.c
../crypto/ecc.c:1387:39: warning: dubious: !x | y
../crypto/ecc.c:1397:47: warning: dubious: !x | y

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-02-14 13:39:33 +08:00
Daniele Alessandrelli
eaffe377e1 crypto: ecc - Export additional helper functions
Export the following additional ECC helper functions:
- ecc_alloc_point()
- ecc_free_point()
- vli_num_bits()
- ecc_point_is_zero()

This is done to allow future ECC device drivers to re-use existing code,
thus simplifying their implementation.

Functions are exported using EXPORT_SYMBOL() (instead of
EXPORT_SYMBOL_GPL()) to be consistent with the functions already
exported by crypto/ecc.c.

Exported functions are documented in include/crypto/internal/ecc.h.

Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-10-29 21:04:03 +08:00
Daniele Alessandrelli
a745d3ace3 crypto: ecc - Move ecc.h to include/crypto/internal
Move ecc.h header file to 'include/crypto/internal' so that it can be
easily imported from everywhere in the kernel tree.

This change is done to allow crypto device drivers to re-use the symbols
exported by 'crypto/ecc.c', thus avoiding code duplication.

Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-10-29 21:04:03 +08:00
Meng Yu
0193b32f56 crypto: ecc - Correct an error in the comments
Remove repeated word 'bit' in comments.

Signed-off-by: Meng Yu <yumeng18@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-26 20:15:56 +11:00
Herbert Xu
3877869d13 Merge branch 'ecc'
This pulls in the NIST P384/256/192 x509 changes.
2021-03-26 19:55:55 +11:00
Saulo Alessandre
149ca1611d crypto: ecc - Add math to support fast NIST P384
Add the math needed for NIST P384 and adapt certain functions'
parameters so that the ecc_curve is passed to vli_mmod_fast. This
allows to identify the curve by its name prefix and the appropriate
function for fast mmod calculation can be used.

Summary of changes:

* crypto/ecc.c
  - add vli_mmod_fast_384
  - change some routines to pass ecc_curve forward until vli_mmod_fast

* crypto/ecc.h
  - add ECC_CURVE_NIST_P384_DIGITS
  - change ECC_MAX_DIGITS to P384 size

Signed-off-by: Saulo Alessandre <saulo.alessandre@tse.jus.br>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-26 19:41:58 +11:00
Saulo Alessandre
703c748d5f crypto: ecc - Add NIST P384 curve parameters
Add the parameters for the NIST P384 curve and define a new curve ID
for it. Make the curve available in ecc_get_curve.

Summary of changes:

* crypto/ecc_curve_defs.h
  - add nist_p384 params

* include/crypto/ecdh.h
  - add ECC_CURVE_NIST_P384

* crypto/ecc.c
  - change ecc_get_curve to accept nist_p384

Signed-off-by: Saulo Alessandre <saulo.alessandre@tse.jus.br>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-26 19:41:58 +11:00
Stefan Berger
4e6602916b crypto: ecdsa - Add support for ECDSA signature verification
Add support for parsing the parameters of a NIST P256 or NIST P192 key.
Enable signature verification using these keys. The new module is
enabled with CONFIG_ECDSA:
  Elliptic Curve Digital Signature Algorithm (NIST P192, P256 etc.)
  is A NIST cryptographic standard algorithm. Only signature verification
  is implemented.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-26 19:41:58 +11:00
Meng Yu
8fb9340e17 crypto: ecc - add curve25519 params and expose them
1. Add curve 25519 parameters in 'crypto/ecc_curve_defs.h';
2. Add curve25519 interface 'ecc_get_curve25519_param' in
   'include/crypto/ecc_curve.h', to make its parameters be
   exposed to everyone in kernel tree.

Signed-off-by: Meng Yu <yumeng18@huawei.com>
Reviewed-by: Zaibo Xu <xuzaibo@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-13 00:04:04 +11:00
Meng Yu
14bb767682 crypto: ecc - expose ecc curves
Move 'ecc_get_curve' to 'include/crypto/ecc_curve.h', so everyone
in kernel tree can easily get ecc curve params;

Signed-off-by: Meng Yu <yumeng18@huawei.com>
Reviewed-by: Zaibo Xu <xuzaibo@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-03-13 00:04:03 +11:00
Waiman Long
453431a549 mm, treewide: rename kzfree() to kfree_sensitive()
As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:22 -07:00
Stephan Müller
6914dd53eb crypto: ecc - SP800-56A rev 3 local public key validation
After the generation of a local public key, SP800-56A rev 3 section
5.6.2.1.3 mandates a validation of that key with a full validation
compliant to section 5.6.2.3.3.

Only if the full validation passes, the key is allowed to be used.

The patch adds the full key validation compliant to 5.6.2.3.3 and
performs the required check on the generated public key.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-31 18:08:59 +10:00
Stephan Müller
e7d2b41e5c crypto: ecdh - check validity of Z before export
SP800-56A rev3 section 5.7.1.2 step 2 mandates that the validity of the
calculated shared secret is verified before the data is returned to the
caller. Thus, the export function and the validity check functions are
reversed. In addition, the sensitive variables of priv and rand_z are
zeroized.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Reviewed-by: Vitaly Chikunov <vt@altlinux.org>
Acked-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-31 18:08:58 +10:00
Alexander A. Klimov
9332a9e739 crypto: Replace HTTP links with HTTPS ones
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-23 17:34:20 +10:00
Ard Biesheuvel
c12d3362a7 int128: move __uint128_t compiler test to Kconfig
In order to use 128-bit integer arithmetic in C code, the architecture
needs to have declared support for it by setting ARCH_SUPPORTS_INT128,
and it requires a version of the toolchain that supports this at build
time. This is why all existing tests for ARCH_SUPPORTS_INT128 also test
whether __SIZEOF_INT128__ is defined, since this is only the case for
compilers that can support 128-bit integers.

Let's fold this additional test into the Kconfig declaration of
ARCH_SUPPORTS_INT128 so that we can also use the symbol in Makefiles,
e.g., to decide whether a certain object needs to be included in the
first place.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-17 09:02:42 +08:00
Ard Biesheuvel
f398243e9f crypto: ecdh - fix big endian bug in ECC library
The elliptic curve arithmetic library used by the EC-DH KPP implementation
assumes big endian byte order, and unconditionally reverses the byte
and word order of multi-limb quantities. On big endian systems, the byte
reordering is not necessary, while the word ordering needs to be retained.

So replace the __swab64() invocation with a call to be64_to_cpu() which
should do the right thing for both little and big endian builds.

Fixes: 3c4b23901a ("crypto: ecdh - Add ECDH software support")
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-01 13:38:31 +08:00
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