kernel/linux.git/crypto/ecc.c, branch v6.6.131

crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP()

2025-07-17T16:35:22+00:00

commit b16510a530d1e6ab9683f04f8fb34f2e0f538275 upstream. Herbert notes that DIV_ROUND_UP() may overflow unnecessarily if an ecdsa implementation's ->key_size() callback returns an unusually large value. Herbert instead suggests (for a division by 8): X / 8 + !!(X & 7) Based on this formula, introduce a generic DIV_ROUND_UP_POW2() macro and use it in lieu of DIV_ROUND_UP() for ->key_size() return values. Additionally, use the macro in ecc_digits_from_bytes(), whose "nbytes" parameter is a ->key_size() return value in some instances, or a user-specified ASN.1 length in the case of ecdsa_get_signature_rs(). Link: https://lore.kernel.org/r/Z3iElsILmoSu6FuC@gondor.apana.org.au/ Signed-off-by: Lukas Wunner Signed-off-by: Lukas Wunner Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: ecc - Prevent ecc_digits_from_bytes from reading too many bytes

2025-01-09T12:31:52+00:00

[ Upstream commit c6ab5c915da460c0397960af3c308386c3f3247b ] 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: d67c96fb97b5 ("crypto: ecdsa - Convert byte arrays with key coordinates to digits") Reviewed-by: Jarkko Sakkinen Signed-off-by: Stefan Berger Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

crypto: ecc - Silence sparse warning

2023-02-14T05:39:33+00:00

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 Reviewed-by: Vitaly Chikunov Signed-off-by: Herbert Xu

crypto: ecc - Export additional helper functions

2021-10-29T13:04:03+00:00

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 Signed-off-by: Herbert Xu

crypto: ecc - Move ecc.h to include/crypto/internal

2021-10-29T13:04:03+00:00

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 Signed-off-by: Herbert Xu

crypto: ecc - Correct an error in the comments

2021-03-26T09:15:56+00:00

Remove repeated word 'bit' in comments. Signed-off-by: Meng Yu Signed-off-by: Herbert Xu

Merge branch 'ecc'

2021-03-26T08:55:55+00:00

This pulls in the NIST P384/256/192 x509 changes.

crypto: ecc - Add math to support fast NIST P384

2021-03-26T08:41:58+00:00

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 Tested-by: Stefan Berger Signed-off-by: Herbert Xu

crypto: ecc - Add NIST P384 curve parameters

2021-03-26T08:41:58+00:00

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 Tested-by: Stefan Berger Acked-by: Jarkko Sakkinen Signed-off-by: Herbert Xu

crypto: ecdsa - Add support for ECDSA signature verification

2021-03-26T08:41:58+00:00

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 Cc: "David S. Miller" Cc: linux-crypto@vger.kernel.org Signed-off-by: Stefan Berger Signed-off-by: Herbert Xu