Differential D26137 Diff 85673 head/sys/dev/if_wg/include/sys/wg_noise.h

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head/sys/dev/if_wg/include/sys/wg_noise.h

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				/*
				* Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
				* Copyright (C) 2019-2020 Matt Dunwoodie <ncon@noconroy.net>
				*
				* Permission to use, copy, modify, and distribute this software for any
				* purpose with or without fee is hereby granted, provided that the above
				* copyright notice and this permission notice appear in all copies.
				*
				* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
				* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
				* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
				* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
				* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
				* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
				* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
				*
				* ======== wg_noise.h ========
				*
				* This file provides a thread safe interface to the Noise protocol as used in
				* WireGuard. The three user facing components are:
				*
				* * noise_local
				* Stores the local state for a noise peer.
				* * noise_remote
				* Stores the remote state for a noise peer.
				* * noise_upcall
				* Stores callback routines for index and peers
				*
				* Additionally a noise_counter, which is invsible to the user is used to track
				* message nonces, to prevent message replay.
				*
				* This module uses Curve25519 for asymmetric crypto, and ChaCha20Poly1305 for
				* symmetric crypto. The handshake uses ephemeral keys, which provide perfect
				* forward secrecy. Keys are NOISE_KEY_SIZE (32) bytes long and can be
				* generated with a CSRNG. While this module will clamp the key to form a valid
				* Curve25519 key, it is recommended that keys are stored in Curve25519 form to
				* preserve interoperability with other systems. Additionally, there is an
				* optional PresharedKey of length NOISE_PSK_SIZE (also 32 bytes), which when
				* used, will provide protection against known quantum attacks. Without it,
				* Curve25519 is broken by Shor's algorithm.
				*
				* -------- noise_local --------
				*
				* void noise_local_init(noise_local , noise_upcall )
				* - Initialise noise_local, should only be called once and before use.
				*
				* int noise_local_set_private(noise_local , uint8_t private)
				* - Set the local private key. This will also calculate the corresponding
				* public key.
				*
				* int noise_local_keys(noise_local , uint8_t public, uint8_t *private)
				* - Get the local keys. It will ensure that a key has been set and if
				* not, will return ENXIO.
				*
				* -------- noise_remote --------
				*
				* void noise_remote_init(noise_remote , uint8_t public)
				* - Initialise noise_local, should only be called once and before use. Key
				* must be provided and it cannot be changed once set.
				*
				* void noise_remote_set_psk(noise_remote , uint8_t psk)
				* - Set the shared key. To remove the shared key, set a key of all 0x00.
				*
				* void noise_remote_keys(noise_remote , uint8_t public, uint8_t *psk)
				* - Get the remote keys.
				*
				* -------- noise_upcall --------
				*
				* The noise_upcall struct is used to lookup incoming public keys, as well as
				* allocate and deallocate index for a remote. The allocation and deallocation
				* are serialised per noise_remote and guaranteed to only have 3 allocated
				* indexes at once.
				*
				* u_arg - passed to callback functions as void *
				* u_get_remote - lookup noise_remote based on public key.
				* u_set_index - allocate index for noise_remote. any further packets that
				* arrive with this index should be passed to noise_* functions
				* with the corresponding noise_remote.
				* u_drop_index - dealloate index passed to callback.
				*
				* -------- crypto --------
				*
				* The following functions are used for the crypto side of things:
				*
				* int noise_create_initiation(noise_remote , noise_initiation )
				* int noise_consume_initiation(noise_local , noise_remote , noise_initiation )
				* int noise_create_response(noise_remote , noise_response )
				* int noise_consume_response(noise_remote , noise_response )
				*
				* int noise_remote_promote(noise_remote *)
				* void noise_remote_clear(noise_remote *)
				* void noise_remote_expire_current(noise_remote *)
				* int noise_remote_encrypt(noise_remote , noise_data , size_t)
				* int noise_remote_decrypt(noise_remote , noise_data , size_t)
				*
				* $FreeBSD$
				*/

				#ifndef __NOISE_H__
				#define __NOISE_H__

				#include <sys/types.h>
				#include <sys/time.h>
				#include <sys/rwlock.h>
				#include <sys/support.h>

				#include <crypto/blake2s.h>
				#include <zinc/chacha20poly1305.h>
				#include <crypto/curve25519.h>

				#define NOISE_KEY_SIZE CURVE25519_KEY_SIZE
				#define NOISE_PSK_SIZE 32
				#define NOISE_MAC_SIZE CHACHA20POLY1305_AUTHTAG_SIZE
				#define NOISE_HASH_SIZE BLAKE2S_HASH_SIZE
				#define NOISE_SYMMETRIC_SIZE CHACHA20POLY1305_KEY_SIZE
				#define NOISE_TIMESTAMP_SIZE 12

				/* Protocol string constants */
				#define NOISE_HANDSHAKE_NAME "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s"
				#define NOISE_IDENTIFIER_NAME "WireGuard v1 zx2c4 Jason@zx2c4.com"

				/* Constants for the counter */
				#define COUNTER_TYPE size_t
				#define COUNTER_BITS_TOTAL 512
				#define COUNTER_TYPE_BITS (sizeof(COUNTER_TYPE) * 8)
				#define COUNTER_TYPE_NUM (COUNTER_BITS_TOTAL / COUNTER_TYPE_BITS)
				#define COUNTER_WINDOW_SIZE (COUNTER_BITS_TOTAL - COUNTER_TYPE_BITS)

				/* Constants for the keypair */
				#define REKEY_AFTER_MESSAGES (1ull << 60)
				#define REJECT_AFTER_MESSAGES (UINT64_MAX - COUNTER_WINDOW_SIZE - 1)
				#define REKEY_AFTER_TIME 120
				#define REKEY_AFTER_TIME_RECV 165
				#define REJECT_AFTER_TIME 180
				#define REJECT_INTERVAL (1000000000 / 50) /* fifty times per sec */
				/* 24 = floor(log2(REJECT_INTERVAL)) */
				#define REJECT_INTERVAL_MASK (~((1ull<<24)-1))

				enum noise_state_hs {
				HS_ZEROED = 0,
				CREATED_INITIATION,
				CONSUMED_INITIATION,
				CREATED_RESPONSE,
				CONSUMED_RESPONSE,
				};

				struct noise_handshake {
				enum noise_state_hs hs_state;
				uint32_t hs_local_index;
				uint32_t hs_remote_index;
				uint8_t hs_e[NOISE_KEY_SIZE];
				uint8_t hs_hash[NOISE_HASH_SIZE];
				uint8_t hs_ck[NOISE_HASH_SIZE];
				};

				struct noise_counter {
				struct rwlock c_lock;
				uint64_t c_send;
				uint64_t c_recv;
				COUNTER_TYPE c_backtrack[COUNTER_TYPE_NUM];
				};

				enum noise_state_kp {
				KP_ZEROED = 0,
				INITIATOR,
				RESPONDER,
				};

				struct noise_keypair {
				SLIST_ENTRY(noise_keypair) kp_entry;
				int kp_valid;
				int kp_is_initiator;
				uint32_t kp_local_index;
				uint32_t kp_remote_index;
				uint8_t kp_send[NOISE_SYMMETRIC_SIZE];
				uint8_t kp_recv[NOISE_SYMMETRIC_SIZE];
				struct timespec kp_birthdate; /* nanouptime */
				struct noise_counter kp_ctr;
				};

				struct noise_remote {
				uint8_t r_public[NOISE_KEY_SIZE];
				struct noise_local *r_local;
				uint8_t r_ss[NOISE_KEY_SIZE];

				struct rwlock r_handshake_lock;
				struct noise_handshake r_handshake;
				uint8_t r_psk[NOISE_PSK_SIZE];
				uint8_t r_timestamp[NOISE_TIMESTAMP_SIZE];
				struct timespec r_last_init; /* nanouptime */

				struct rwlock r_keypair_lock;
				SLIST_HEAD(,noise_keypair) r_unused_keypairs;
				struct noise_keypair r_next, r_current, *r_previous;
				struct noise_keypair r_keypair[3]; /* 3: next, current, previous. */

				};

				struct noise_local {
				struct rwlock l_identity_lock;
				int l_has_identity;
				uint8_t l_public[NOISE_KEY_SIZE];
				uint8_t l_private[NOISE_KEY_SIZE];

				struct noise_upcall {
				void *u_arg;
				struct noise_remote *
				(u_remote_get)(void , uint8_t[NOISE_KEY_SIZE]);
				uint32_t
				(u_index_set)(void , struct noise_remote *);
				void (u_index_drop)(void , uint32_t);
				} l_upcall;
				};

				struct noise_initiation {
				uint32_t s_idx;
				uint8_t ue[NOISE_KEY_SIZE];
				uint8_t es[NOISE_KEY_SIZE + NOISE_MAC_SIZE];
				uint8_t ets[NOISE_TIMESTAMP_SIZE + NOISE_MAC_SIZE];
				} __packed;

				struct noise_response {
				uint32_t s_idx;
				uint32_t r_idx;
				uint8_t ue[NOISE_KEY_SIZE];
				uint8_t en[0 + NOISE_MAC_SIZE];
				} __packed;

				struct noise_data {
				uint32_t r_idx;
				uint64_t nonce;
				uint8_t buf[];
				} __packed;


				/* Set/Get noise parameters */
				void noise_local_init(struct noise_local , struct noise_upcall );
				void noise_local_lock_identity(struct noise_local *);
				void noise_local_unlock_identity(struct noise_local *);
				int noise_local_set_private(struct noise_local *, uint8_t[NOISE_KEY_SIZE]);
				int noise_local_keys(struct noise_local *, uint8_t[NOISE_KEY_SIZE],
				uint8_t[NOISE_KEY_SIZE]);

				void noise_remote_init(struct noise_remote *, const uint8_t[NOISE_KEY_SIZE],
				struct noise_local *);
				int noise_remote_set_psk(struct noise_remote *, const uint8_t[NOISE_PSK_SIZE]);
				int noise_remote_keys(struct noise_remote *, uint8_t[NOISE_KEY_SIZE],
				uint8_t[NOISE_PSK_SIZE]);

				/* Should be called anytime noise_local_set_private is called */
				void noise_remote_precompute(struct noise_remote *);

				/* Cryptographic functions */
				int noise_create_initiation(
				struct noise_remote *,
				struct noise_initiation *);

				int noise_consume_initiation(
				struct noise_local *,
				struct noise_remote **,
				struct noise_initiation *);

				int noise_create_response(
				struct noise_remote *,
				struct noise_response *);

				int noise_consume_response(
				struct noise_remote *,
				struct noise_response *);

				int noise_remote_begin_session(struct noise_remote *);
				void noise_remote_clear(struct noise_remote *);
				void noise_remote_expire_current(struct noise_remote *);

				int noise_remote_ready(struct noise_remote *);

				int noise_remote_encrypt(
				struct noise_remote *,
				struct noise_data *,
				size_t);
				int noise_remote_decrypt(
				struct noise_remote *,
				struct noise_data *,
				size_t);

				#endif /* __NOISE_H__ */