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Diffstat (limited to 'src/noise.h')
| -rw-r--r-- | src/noise.h | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/src/noise.h b/src/noise.h new file mode 100644 index 0000000..65ca9d8 --- /dev/null +++ b/src/noise.h @@ -0,0 +1,153 @@ +/* + * Copyright 2015-2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + * + * See doc/protocol.md and https://github.com/trevp/noise/blob/master/noise.md for more info + */ + +#ifndef NOISE_H +#define NOISE_H + +#include "crypto/curve25519.h" +#include "crypto/chacha20poly1305.h" +#include "crypto/blake2s.h" +#include <linux/types.h> +#include <linux/spinlock.h> +#include <linux/atomic.h> +#include <linux/rwsem.h> +#include <linux/mutex.h> +#include <linux/jiffies.h> + +enum index_hashtable_type { + INDEX_HASHTABLE_HANDSHAKE = (1 << 0), + INDEX_HASHTABLE_KEYPAIR = (1 << 1) +}; + +struct index_hashtable_entry { + struct wireguard_peer *peer; + struct hlist_node index_hash; + enum index_hashtable_type type; + __le32 index; +}; + +enum noise_lengths { + NOISE_PUBLIC_KEY_LEN = CURVE25519_POINT_SIZE, + NOISE_SYMMETRIC_KEY_LEN = CHACHA20POLY1305_KEYLEN, + NOISE_TIMESTAMP_LEN = sizeof(u64) + sizeof(u32), + NOISE_AUTHTAG_LEN = CHACHA20POLY1305_AUTHTAGLEN, + NOISE_HASH_LEN = BLAKE2S_OUTBYTES +}; + +enum wireguard_limits { + REKEY_AFTER_MESSAGES = U64_MAX - 0xffff, + REJECT_AFTER_MESSAGES = U64_MAX - 0xf, /* It's important that this value is always at *least* one less than U64_MAX. */ + REKEY_TIMEOUT = 5 * HZ, + REKEY_AFTER_TIME = 120 * HZ, + REJECT_AFTER_TIME = 180 * HZ, + INITIATIONS_PER_SECOND = HZ / 50, + MAX_PEERS_PER_DEVICE = U16_MAX +}; + +union noise_counter { + struct { + u64 counter; + unsigned long backtrack; + spinlock_t lock; + } receive; + atomic64_t counter; +}; + +struct noise_symmetric_key { + u8 key[NOISE_SYMMETRIC_KEY_LEN]; + union noise_counter counter; + uint64_t birthdate; + bool is_valid; +}; + +struct noise_keypair { + struct index_hashtable_entry entry; + struct noise_symmetric_key sending; + struct noise_symmetric_key receiving; + __le32 remote_index; + bool i_am_the_initiator; + struct kref refcount; + struct rcu_head rcu; + uint64_t internal_id; +}; + +struct noise_keypairs { + struct noise_keypair __rcu *current_keypair; + struct noise_keypair __rcu *previous_keypair; + struct noise_keypair __rcu *next_keypair; + struct mutex keypair_update_lock; +}; + +struct noise_static_identity { + bool has_identity, has_psk; + u8 static_public[NOISE_PUBLIC_KEY_LEN]; + u8 static_private[NOISE_PUBLIC_KEY_LEN]; + u8 preshared_key[NOISE_SYMMETRIC_KEY_LEN]; + struct rw_semaphore lock; +}; + +enum noise_handshake_state { + HANDSHAKE_ZEROED, + HANDSHAKE_CREATED_INITIATION, + HANDSHAKE_CONSUMED_INITIATION, + HANDSHAKE_CREATED_RESPONSE, + HANDSHAKE_CONSUMED_RESPONSE +}; + +struct noise_handshake { + struct index_hashtable_entry entry; + + enum noise_handshake_state state; + uint64_t last_initiation_consumption; + + struct noise_static_identity *static_identity; + + u8 ephemeral_public[NOISE_PUBLIC_KEY_LEN]; + u8 ephemeral_private[NOISE_PUBLIC_KEY_LEN]; + + u8 remote_static[NOISE_PUBLIC_KEY_LEN]; + u8 remote_ephemeral[NOISE_PUBLIC_KEY_LEN]; + + u8 key[NOISE_SYMMETRIC_KEY_LEN]; + u8 hash[NOISE_HASH_LEN]; + u8 chaining_key[NOISE_HASH_LEN]; + + u8 latest_timestamp[NOISE_TIMESTAMP_LEN]; + __le32 remote_index; + + /* Protects all members except the immutable (after noise_peer_init): remote_static, static_identity */ + struct rw_semaphore lock; +}; + +#define noise_encrypted_len(plain_len) (plain_len + NOISE_AUTHTAG_LEN) + +struct wireguard_peer; +struct wireguard_device; +struct message_header; +struct message_handshake_initiation; +struct message_handshake_response; +struct message_data; +struct message_handshake_cookie; + +void noise_init(void); +void noise_handshake_init(struct noise_handshake *handshake, struct noise_static_identity *static_identity, const u8 peer_public_key[NOISE_PUBLIC_KEY_LEN], struct wireguard_peer *peer); +void noise_handshake_clear(struct noise_handshake *handshake); +void noise_keypair_put(struct noise_keypair *keypair); +void noise_keypairs_clear(struct noise_keypairs *keypairs); +bool noise_received_with_keypair(struct noise_keypairs *keypairs, struct noise_keypair *received_keypair); + +void noise_set_static_identity_private_key(struct noise_static_identity *static_identity, const u8 private_key[NOISE_PUBLIC_KEY_LEN]); +void noise_set_static_identity_preshared_key(struct noise_static_identity *static_identity, const u8 preshared_key[NOISE_SYMMETRIC_KEY_LEN]); + +bool noise_handshake_create_initiation(struct message_handshake_initiation *dst, struct noise_handshake *handshake); +struct wireguard_peer *noise_handshake_consume_initiation(struct message_handshake_initiation *src, struct wireguard_device *wg); + +bool noise_handshake_create_response(struct message_handshake_response *dst, struct noise_handshake *peer); +struct wireguard_peer *noise_handshake_consume_response(struct message_handshake_response *src, struct wireguard_device *wg); + +bool noise_handshake_begin_session(struct noise_handshake *handshake, struct noise_keypairs *keypairs, bool i_am_the_initiator); + +#endif |