Commit 2143d622 authored by Eric Biggers's avatar Eric Biggers
Browse files

lib/crypto: curve25519: Add at_least decoration to fixed-size array params 



Add the at_least (i.e. 'static') decoration to the fixed-size array
parameters of the curve25519 library functions.  This causes clang to
warn when a too-small array of known size is passed.

Acked-by: default avatarArd Biesheuvel <ardb@kernel.org>
Acked-by: default avatar"Jason A. Donenfeld" <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20251122194206.31822-3-ebiggers@kernel.org


Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
parent 1b31b43b

include/crypto/curve25519.h

+14 −10
Original line number Diff line number Diff line
@@ -13,24 +13,28 @@ enum curve25519_lengths { 
	CURVE25519_KEY_SIZE = 32

};



void curve25519_generic(u8 out[CURVE25519_KEY_SIZE],

			const u8 scalar[CURVE25519_KEY_SIZE],

			const u8 point[CURVE25519_KEY_SIZE]);

void curve25519_generic(u8 out[at_least CURVE25519_KEY_SIZE],

			const u8 scalar[at_least CURVE25519_KEY_SIZE],

			const u8 point[at_least CURVE25519_KEY_SIZE]);



bool __must_check curve25519(u8 mypublic[CURVE25519_KEY_SIZE],

			     const u8 secret[CURVE25519_KEY_SIZE],

			     const u8 basepoint[CURVE25519_KEY_SIZE]);

bool __must_check

curve25519(u8 mypublic[at_least CURVE25519_KEY_SIZE],

	   const u8 secret[at_least CURVE25519_KEY_SIZE],

	   const u8 basepoint[at_least CURVE25519_KEY_SIZE]);



bool __must_check curve25519_generate_public(u8 pub[CURVE25519_KEY_SIZE],

					     const u8 secret[CURVE25519_KEY_SIZE]);

bool __must_check

curve25519_generate_public(u8 pub[at_least CURVE25519_KEY_SIZE],

			   const u8 secret[at_least CURVE25519_KEY_SIZE]);



static inline void curve25519_clamp_secret(u8 secret[CURVE25519_KEY_SIZE])

static inline void

curve25519_clamp_secret(u8 secret[at_least CURVE25519_KEY_SIZE])

{

	secret[0] &= 248;

	secret[31] = (secret[31] & 127) | 64;

}



static inline void curve25519_generate_secret(u8 secret[CURVE25519_KEY_SIZE])

static inline void

curve25519_generate_secret(u8 secret[at_least CURVE25519_KEY_SIZE])

{

	get_random_bytes_wait(secret, CURVE25519_KEY_SIZE);

	curve25519_clamp_secret(secret);