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Diffstat (limited to 'src/crypto/zinc/curve25519/curve25519.c')
-rw-r--r-- | src/crypto/zinc/curve25519/curve25519.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/src/crypto/zinc/curve25519/curve25519.c b/src/crypto/zinc/curve25519/curve25519.c new file mode 100644 index 0000000..183eeb5 --- /dev/null +++ b/src/crypto/zinc/curve25519/curve25519.c @@ -0,0 +1,83 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + * + * This is an implementation of the Curve25519 ECDH algorithm, using either + * a 32-bit implementation or a 64-bit implementation with 128-bit integers, + * depending on what is supported by the target compiler. + * + * Information: https://cr.yp.to/ecdh.html + */ + +#include <zinc/curve25519.h> + +#include <asm/unaligned.h> +#include <linux/version.h> +#include <linux/string.h> +#include <linux/random.h> +#include <crypto/algapi.h> + +#ifndef HAVE_CURVE25519_ARCH_IMPLEMENTATION +void __init curve25519_fpu_init(void) +{ +} +static inline bool curve25519_arch(u8 mypublic[CURVE25519_POINT_SIZE], + const u8 secret[CURVE25519_POINT_SIZE], + const u8 basepoint[CURVE25519_POINT_SIZE]) +{ + return false; +} +static inline bool curve25519_base_arch(u8 pub[CURVE25519_POINT_SIZE], + const u8 secret[CURVE25519_POINT_SIZE]) +{ + return false; +} +#endif + +static __always_inline void normalize_secret(u8 secret[CURVE25519_POINT_SIZE]) +{ + secret[0] &= 248; + secret[31] &= 127; + secret[31] |= 64; +} + +#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__) +#include "curve25519-hacl64.h" +#else +#include "curve25519-fiat32.h" +#endif + +static const u8 null_point[CURVE25519_POINT_SIZE] = { 0 }; + +bool curve25519(u8 mypublic[CURVE25519_POINT_SIZE], + const u8 secret[CURVE25519_POINT_SIZE], + const u8 basepoint[CURVE25519_POINT_SIZE]) +{ + if (!curve25519_arch(mypublic, secret, basepoint)) + curve25519_generic(mypublic, secret, basepoint); + return crypto_memneq(mypublic, null_point, CURVE25519_POINT_SIZE); +} +EXPORT_SYMBOL(curve25519); + +bool curve25519_generate_public(u8 pub[CURVE25519_POINT_SIZE], + const u8 secret[CURVE25519_POINT_SIZE]) +{ + static const u8 basepoint[CURVE25519_POINT_SIZE] __aligned(32) = { 9 }; + + if (unlikely(!crypto_memneq(secret, null_point, CURVE25519_POINT_SIZE))) + return false; + + if (curve25519_base_arch(pub, secret)) + return crypto_memneq(pub, null_point, CURVE25519_POINT_SIZE); + return curve25519(pub, secret, basepoint); +} +EXPORT_SYMBOL(curve25519_generate_public); + +void curve25519_generate_secret(u8 secret[CURVE25519_POINT_SIZE]) +{ + get_random_bytes_wait(secret, CURVE25519_POINT_SIZE); + normalize_secret(secret); +} +EXPORT_SYMBOL(curve25519_generate_secret); + +#include "../selftest/curve25519.h" |