1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
(*****************************************************************************)
(* *)
(* Open Source License *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
(* *)
(* Permission is hereby granted, free of charge, to any person obtaining a *)
(* copy of this software and associated documentation files (the "Software"),*)
(* to deal in the Software without restriction, including without limitation *)
(* the rights to use, copy, modify, merge, publish, distribute, sublicense, *)
(* and/or sell copies of the Software, and to permit persons to whom the *)
(* Software is furnished to do so, subject to the following conditions: *)
(* *)
(* The above copyright notice and this permission notice shall be included *)
(* in all copies or substantial portions of the Software. *)
(* *)
(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *)
(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *)
(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *)
(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *)
(* DEALINGS IN THE SOFTWARE. *)
(* *)
(*****************************************************************************)
(* Tezos Protocol Implementation - Random number generation *)
type seed = B of State_hash.t
type t = T of State_hash.t
type sequence = S of State_hash.t
type nonce = MBytes.t
let nonce_encoding = Data_encoding.Fixed.bytes Constants_repr.nonce_length
let init = "Laissez-faire les proprietaires."
let zero_bytes = MBytes.of_string (String.make Nonce_hash.size '\000')
let state_hash_encoding =
let open Data_encoding in
conv
State_hash.to_bytes
State_hash.of_bytes_exn
(Fixed.bytes Nonce_hash.size)
let seed_encoding =
let open Data_encoding in
conv (fun (B b) -> b) (fun b -> B b) state_hash_encoding
let empty = B (State_hash.hash_bytes [MBytes.of_string init])
let nonce (B state) nonce =
B (State_hash.hash_bytes [State_hash.to_bytes state; nonce])
let initialize_new (B state) append =
T (State_hash.hash_bytes (State_hash.to_bytes state :: zero_bytes :: append))
let xor_higher_bits i b =
let higher = MBytes.get_int32 b 0 in
let r = Int32.logxor higher i in
let res = MBytes.copy b in
MBytes.set_int32 res 0 r ; res
let sequence (T state) n =
State_hash.to_bytes state |> xor_higher_bits n
|> fun b -> S (State_hash.hash_bytes [b])
let take (S state) =
let b = State_hash.to_bytes state in
let h = State_hash.hash_bytes [b] in
(State_hash.to_bytes h, S h)
let take_int32 s bound =
if Compare.Int32.(bound <= 0l) then invalid_arg "Seed_repr.take_int32"
(* FIXME *)
else
let rec loop s =
let (bytes, s) = take s in
let r = Int32.abs (MBytes.get_int32 bytes 0) in
let drop_if_over =
Int32.sub Int32.max_int (Int32.rem Int32.max_int bound)
in
if Compare.Int32.(r >= drop_if_over) then loop s
else
let v = Int32.rem r bound in
(v, s)
in
loop s
type error += Unexpected_nonce_length (* `Permanent *)
let () =
register_error_kind
`Permanent
~id:"unexpected_nonce_length"
~title:"Unexpected nonce length"
~description:"Nonce length is incorrect."
~pp:(fun ppf () ->
Format.fprintf
ppf
"Nonce length is not %i bytes long as it should."
Constants_repr.nonce_length)
Data_encoding.empty
(function Unexpected_nonce_length -> Some () | _ -> None)
(fun () -> Unexpected_nonce_length)
let make_nonce nonce =
if Compare.Int.(MBytes.length nonce <> Constants_repr.nonce_length) then
error Unexpected_nonce_length
else ok nonce
let hash nonce = Nonce_hash.hash_bytes [nonce]
let check_hash nonce hash =
Compare.Int.(MBytes.length nonce = Constants_repr.nonce_length)
&& Nonce_hash.equal (Nonce_hash.hash_bytes [nonce]) hash
let nonce_hash_key_part = Nonce_hash.to_path
let initial_nonce_0 = zero_bytes
let initial_nonce_hash_0 = hash initial_nonce_0
let deterministic_seed seed = nonce seed zero_bytes
let initial_seeds n =
let rec loop acc elt i =
if Compare.Int.(i = 1) then List.rev (elt :: acc)
else loop (elt :: acc) (deterministic_seed elt) (i - 1)
in
loop [] (B (State_hash.hash_bytes [])) n