3f523e1240
Since we're doing a static inline dispatch here, we normally branch based on whether or not there's an arch implementation. That would have been fine in general, except the crypto Makefile prior used to turn things off -- despite the Kconfig -- resulting in us needing to also hard code various assembler things into the dispatcher too. The horror! Now that the assembler config options are done by Kconfig, we can get rid of the inconsistency. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
72 lines
2 KiB
C
72 lines
2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 OR MIT */
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/*
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* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
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*/
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#ifndef CURVE25519_H
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#define CURVE25519_H
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#include <crypto/algapi.h> // For crypto_memneq.
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#include <linux/types.h>
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#include <linux/random.h>
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enum curve25519_lengths {
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CURVE25519_KEY_SIZE = 32
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};
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extern const u8 curve25519_null_point[];
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extern const u8 curve25519_base_point[];
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void curve25519_generic(u8 out[CURVE25519_KEY_SIZE],
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const u8 scalar[CURVE25519_KEY_SIZE],
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const u8 point[CURVE25519_KEY_SIZE]);
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void curve25519_arch(u8 out[CURVE25519_KEY_SIZE],
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const u8 scalar[CURVE25519_KEY_SIZE],
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const u8 point[CURVE25519_KEY_SIZE]);
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void curve25519_base_arch(u8 pub[CURVE25519_KEY_SIZE],
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const u8 secret[CURVE25519_KEY_SIZE]);
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static inline
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bool __must_check curve25519(u8 mypublic[CURVE25519_KEY_SIZE],
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const u8 secret[CURVE25519_KEY_SIZE],
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const u8 basepoint[CURVE25519_KEY_SIZE])
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{
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if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519))
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curve25519_arch(mypublic, secret, basepoint);
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else
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curve25519_generic(mypublic, secret, basepoint);
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return crypto_memneq(mypublic, curve25519_null_point,
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CURVE25519_KEY_SIZE);
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}
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static inline bool
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__must_check curve25519_generate_public(u8 pub[CURVE25519_KEY_SIZE],
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const u8 secret[CURVE25519_KEY_SIZE])
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{
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if (unlikely(!crypto_memneq(secret, curve25519_null_point,
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CURVE25519_KEY_SIZE)))
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return false;
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if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519))
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curve25519_base_arch(pub, secret);
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else
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curve25519_generic(pub, secret, curve25519_base_point);
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return crypto_memneq(pub, curve25519_null_point, CURVE25519_KEY_SIZE);
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}
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static inline void curve25519_clamp_secret(u8 secret[CURVE25519_KEY_SIZE])
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{
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secret[0] &= 248;
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secret[31] = (secret[31] & 127) | 64;
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}
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static inline void curve25519_generate_secret(u8 secret[CURVE25519_KEY_SIZE])
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{
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get_random_bytes_wait(secret, CURVE25519_KEY_SIZE);
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curve25519_clamp_secret(secret);
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}
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#endif /* CURVE25519_H */
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