projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 0ed42a6f JD |
1 | /* SPDX-License-Identifier: GPL-2.0 OR MIT */ |
| 2 | /* | |
| 3 | * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. | |
| 4 | */ | |
| 5 | ||
| 6 | #ifndef CURVE25519_H | |
| 7 | #define CURVE25519_H | |
| 8 | ||
| 9 | #include <crypto/algapi.h> // For crypto_memneq. | |
| 10 | #include <linux/types.h> | |
| 11 | #include <linux/random.h> | |
| 12 | ||
| 13 | enum curve25519_lengths { | |
| 14 | CURVE25519_KEY_SIZE = 32 | |
| 15 | }; | |
| 16 | ||
| 17 | extern const u8 curve25519_null_point[]; | |
| 18 | extern const u8 curve25519_base_point[]; | |
| 19 | ||
| 20 | void curve25519_generic(u8 out[CURVE25519_KEY_SIZE], | |
| 21 | const u8 scalar[CURVE25519_KEY_SIZE], | |
| 22 | const u8 point[CURVE25519_KEY_SIZE]); | |
| 23 | ||
| 24 | void curve25519_arch(u8 out[CURVE25519_KEY_SIZE], | |
| 25 | const u8 scalar[CURVE25519_KEY_SIZE], | |
| 26 | const u8 point[CURVE25519_KEY_SIZE]); | |
| 27 | ||
| 28 | void curve25519_base_arch(u8 pub[CURVE25519_KEY_SIZE], | |
| 29 | const u8 secret[CURVE25519_KEY_SIZE]); | |
| 30 | ||
| 31 | static inline | |
| 32 | bool __must_check curve25519(u8 mypublic[CURVE25519_KEY_SIZE], | |
| 33 | const u8 secret[CURVE25519_KEY_SIZE], | |
| 34 | const u8 basepoint[CURVE25519_KEY_SIZE]) | |
| 35 | { | |
| 36 | if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519)) | |
| 37 | curve25519_arch(mypublic, secret, basepoint); | |
| 38 | else | |
| 39 | curve25519_generic(mypublic, secret, basepoint); | |
| 40 | return crypto_memneq(mypublic, curve25519_null_point, | |
| 41 | CURVE25519_KEY_SIZE); | |
| 42 | } | |
| 43 | ||
| 44 | static inline bool | |
| 45 | __must_check curve25519_generate_public(u8 pub[CURVE25519_KEY_SIZE], | |
| 46 | const u8 secret[CURVE25519_KEY_SIZE]) | |
| 47 | { | |
| 48 | if (unlikely(!crypto_memneq(secret, curve25519_null_point, | |
| 49 | CURVE25519_KEY_SIZE))) | |
| 50 | return false; | |
| 51 | ||
| 52 | if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CURVE25519)) | |
| 53 | curve25519_base_arch(pub, secret); | |
| 54 | else | |
| 55 | curve25519_generic(pub, secret, curve25519_base_point); | |
| 56 | return crypto_memneq(pub, curve25519_null_point, CURVE25519_KEY_SIZE); | |
| 57 | } | |
| 58 | ||
| 59 | static inline void curve25519_clamp_secret(u8 secret[CURVE25519_KEY_SIZE]) | |
| 60 | { | |
| 61 | secret[0] &= 248; | |
| 62 | secret[31] = (secret[31] & 127) | 64; | |
| 63 | } | |
| 64 | ||
| 65 | static inline void curve25519_generate_secret(u8 secret[CURVE25519_KEY_SIZE]) | |
| 66 | { | |
| 67 | get_random_bytes_wait(secret, CURVE25519_KEY_SIZE); | |
| 68 | curve25519_clamp_secret(secret); | |
| 69 | } | |
| 70 | ||
| 71 | #endif /* CURVE25519_H */ |