100 lines
3.3 KiB
OCaml
100 lines
3.3 KiB
OCaml
(**************************************************************************)
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(* *)
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(* Copyright (c) 2014 - 2016. *)
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(* Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
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(* *)
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(* All rights reserved. No warranty, explicit or implicit, provided. *)
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(* *)
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(**************************************************************************)
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open Utils
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(** Tezos - X25519/XSalsa20-Poly1305 cryptography *)
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type secret_key = Sodium.Box.secret_key
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type public_key = Sodium.Box.public_key
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type channel_key = Sodium.Box.channel_key
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type nonce = Sodium.Box.nonce
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type target = int64 list (* used as unsigned intergers... *)
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exception TargetNot256Bit
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module Public_key_hash = Hash.Make_Blake2B (Base48) (struct
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let name = "Crypto_box.Public_key_hash"
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let title = "A Cryptobox public key ID"
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let b48check_prefix = Base48.Prefix.cryptobox_public_key_hash
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let size = Some 16
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end)
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let hash pk =
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Public_key_hash.hash_bytes [Sodium.Box.Bigbytes.of_public_key pk]
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let random_keypair () =
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let sk, pk = Sodium.Box.random_keypair () in
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sk, pk, hash pk
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let random_nonce = Sodium.Box.random_nonce
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let increment_nonce = Sodium.Box.increment_nonce
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let box = Sodium.Box.Bigbytes.box
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let box_open sk pk msg nonce =
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try Some (Sodium.Box.Bigbytes.box_open sk pk msg nonce) with
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| Sodium.Verification_failure -> None
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let precompute = Sodium.Box.precompute
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let fast_box = Sodium.Box.Bigbytes.fast_box
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let fast_box_open ck msg nonce =
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try Some (Sodium.Box.Bigbytes.fast_box_open ck msg nonce) with
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| Sodium.Verification_failure -> None
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let make_target target =
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if List.length target > 8 then raise TargetNot256Bit ;
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target
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(* Compare a SHA256 hash to a 256bits-target prefix.
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The prefix is a list of "unsigned" int64. *)
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let compare_target hash target =
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let hash = Hash.Generic_hash.to_string hash in
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let rec check offset = function
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| [] -> true
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| x :: xs ->
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Compare.Uint64.(EndianString.BigEndian.get_int64 hash offset <= x)
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&& check (offset + 8) xs in
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check 0 target
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let default_target =
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(* FIXME we use an easy target until we allow custom configuration. *)
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[ Int64.shift_left 1L 48 ]
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let check_proof_of_work pk nonce target =
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let hash =
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Hash.Generic_hash.hash_bytes [
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Sodium.Box.Bigbytes.of_public_key pk ;
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Sodium.Box.Bigbytes.of_nonce nonce ;
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] in
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compare_target hash target
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let generate_proof_of_work pk target =
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let rec loop nonce =
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if check_proof_of_work pk nonce target then nonce
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else loop (increment_nonce nonce) in
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loop (random_nonce ())
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let public_key_encoding =
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let open Data_encoding in
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conv
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Sodium.Box.Bigbytes.of_public_key
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Sodium.Box.Bigbytes.to_public_key
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(Fixed.bytes Sodium.Box.public_key_size)
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let secret_key_encoding =
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let open Data_encoding in
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conv
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Sodium.Box.Bigbytes.of_secret_key
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Sodium.Box.Bigbytes.to_secret_key
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(Fixed.bytes Sodium.Box.secret_key_size)
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let nonce_encoding =
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let open Data_encoding in
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conv
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Sodium.Box.Bigbytes.of_nonce
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Sodium.Box.Bigbytes.to_nonce
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(Fixed.bytes Sodium.Box.nonce_size)
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