100 lines
4.3 KiB
OCaml
100 lines
4.3 KiB
OCaml
(*****************************************************************************)
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(* *)
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(* Open Source License *)
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(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
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(* *)
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(* Permission is hereby granted, free of charge, to any person obtaining a *)
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(* copy of this software and associated documentation files (the "Software"),*)
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(* to deal in the Software without restriction, including without limitation *)
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(* the rights to use, copy, modify, merge, publish, distribute, sublicense, *)
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(* and/or sell copies of the Software, and to permit persons to whom the *)
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(* Software is furnished to do so, subject to the following conditions: *)
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(* *)
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(* The above copyright notice and this permission notice shall be included *)
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(* in all copies or substantial portions of the Software. *)
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(* *)
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(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
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(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *)
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(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *)
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(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
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(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *)
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(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *)
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(* DEALINGS IN THE SOFTWARE. *)
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(* *)
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(*****************************************************************************)
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(** Tezos Protocol Implementation - Random number generation
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This is not expected to be a good cryptographic random number
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generator. In particular this is supposed to be used in situations
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where the seed is a globaly known information.
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The only expected property is: It should be difficult to find a
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seed such that the generated sequence is a given one. *)
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(** {2 Random Generation} ****************************************************)
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(** The state of the random number generator *)
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type t
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(** A random seed, to derive random sequences from *)
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type seed
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(** A random sequence, to derive random values from *)
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type sequence
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(** [initialize_new state ident] returns a new generator *)
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val initialize_new : seed -> MBytes.t list -> t
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(** [sequence state n] prepares the n-th sequence of a state *)
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val sequence : t -> int32 -> sequence
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(** Generates the next random value in the sequence *)
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val take : sequence -> MBytes.t * sequence
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(** Generates the next random value as a bounded [int32] *)
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val take_int32 : sequence -> int32 -> int32 * sequence
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(** {2 Predefined seeds} *****************************************************)
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val empty : seed
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(** Returns a new seed by hashing the one passed with a constant. *)
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val deterministic_seed : seed -> seed
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(** [intial_seeds n] generates the first [n] seeds for which there are no nonces.
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The first seed is a constant value. The kth seed is the hash of seed (k-1)
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concatenated with a constant. *)
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val initial_seeds : int -> seed list
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(** {2 Entropy} **************************************************************)
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(** A nonce for adding entropy to the generator *)
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type nonce
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(** Add entropy to the seed generator *)
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val nonce : seed -> nonce -> seed
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(** Use a byte sequence as a nonce *)
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val make_nonce : MBytes.t -> nonce tzresult
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(** Compute the has of a nonce *)
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val hash : nonce -> Nonce_hash.t
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(** [check_hash nonce hash] is true if the nonce correspond to the hash *)
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val check_hash : nonce -> Nonce_hash.t -> bool
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(** For using nonce hashes as keys in the hierarchical database *)
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val nonce_hash_key_part : Nonce_hash.t -> string list -> string list
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(** {2 Predefined nonce} *****************************************************)
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val initial_nonce_0 : nonce
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val initial_nonce_hash_0 : Nonce_hash.t
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(** {2 Serializers} **********************************************************)
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val nonce_encoding : nonce Data_encoding.t
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val seed_encoding : seed Data_encoding.t
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