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>
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>
For NIST P192/256/384 the public key's x and y parameters could be copied
directly from a given array since both parameters filled 'ndigits' of
digits (a 'digit' is a u64). For support of NIST P521 the key parameters
need to have leading zeros prepended to the most significant digit since
only 2 bytes of the most significant digit are provided.
Therefore, implement ecc_digits_from_bytes to convert a byte array into an
array of digits and use this function in ecdsa_set_pub_key where an input
byte array needs to be converted into digits.
Suggested-by: Lukas Wunner <lukas@wunner.de>
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>
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>
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>
