Source file core.ml
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(** This module implements all the core functionalities. It contains also the low
level Rustzcash type equalities and should be used in its Raw form only for
testing.
For all other uses refer to its Client or Validator interfaces. *)
module Raw = struct
module R = Rustzcash
let init_params = R.init_params
module Spending_key = struct
(** Authorisation spending key: secret key used to sign once randomized. *)
type ask = R.ask
(** Nullifier secret key. Used to compute nullifier. *)
type nsk = R.nsk
type ovk = R.ovk
type expanded_spending_key = R.expanded_spending_key = {
ask : ask;
nsk : nsk;
ovk : ovk;
}
let _to_expanded_spending_key = R.to_expanded_spending_key
let expsk_encoding =
let open Data_encoding in
def "sapling.wallet.expanded_spending_key"
@@ conv
(fun t -> (t.ask, t.nsk, t.ovk))
(fun (ask, nsk, ovk) -> {ask; nsk; ovk})
(obj3
(req "ask" (conv R.of_ask R.to_ask (Fixed.bytes 32)))
(req "nsk" (conv R.of_nsk R.to_nsk (Fixed.bytes 32)))
(req "ovk" (conv R.of_ovk R.to_ovk (Fixed.bytes 32))))
(** Type t contains ask, nsk, ovk and zip-32 related info. *)
type t = R.zip32_expanded_spending_key = {
depth : Bytes.t;
parent_fvk_tag : Bytes.t;
child_index : Bytes.t;
chain_code : Bytes.t;
expsk : expanded_spending_key;
dk : Bytes.t;
}
let of_bytes b = Option.catch (fun () -> R.to_zip32_expanded_spending_key b)
let to_bytes = R.of_zip32_expanded_spending_key
let encoding =
let open Data_encoding in
def "sapling.wallet.spending_key"
@@ conv
(fun t ->
( t.depth,
t.parent_fvk_tag,
t.child_index,
t.chain_code,
t.expsk,
t.dk ))
(fun (depth, parent_fvk_tag, child_index, chain_code, expsk, dk) ->
{depth; parent_fvk_tag; child_index; chain_code; expsk; dk})
(obj6
(req "depth" (Fixed.bytes 1))
(req "parent_fvk_tag" (Fixed.bytes 4))
(req "child_index" (Fixed.bytes 4))
(req "chain_code" (Fixed.bytes 32))
(req "expsk" expsk_encoding)
(req "dk" (Fixed.bytes 32)))
type Tezos_crypto.Base58.data += Data of t
let b58check_encoding =
let to_raw sk = Bytes.to_string @@ to_bytes sk in
let of_raw str = of_bytes (Bytes.of_string str) in
Tezos_crypto.Base58.register_encoding
~prefix:Tezos_crypto.Base58.Prefix.sapling_spending_key
~length:169
~to_raw
~of_raw
~wrap:(fun x -> Data x)
let () =
Tezos_crypto.Base58.check_encoded_prefix b58check_encoding "sask" 241
let of_seed = R.zip32_xsk_master
let derive_key = R.zip32_xsk_derive
let child_index sk = Bytes.get_int32_be sk.child_index 0
end
module Viewing_key = struct
(** Public signature key.
Note: if this key is exposed there is privacy loss! Only randomised
version of it (rk) are published. *)
type ak = R.ak
(** Public nullifier key.
Note: if this key is exposed there is privacy loss! Only randomised
version of it (rk) are published. *)
type nk = R.nk
type ivk = R.ivk
type pkd = R.pkd
type ovk = R.ovk
(** Used to create an address from a viewing key. *)
type diversifier = R.diversifier
let diversifier_encoding =
let open Data_encoding in
def "sapling.wallet.diversifier"
@@ conv
R.of_diversifier
(fun b ->
match R.to_diversifier b with
| Some diversifier -> diversifier
| None -> raise (Invalid_argument "diversifier_encoding: decoding"))
(Fixed.bytes 11)
(** Full viewing key contains ak, nsk, ovk *)
type full_viewing_key = R.full_viewing_key = {ak : ak; nk : nk; ovk : ovk}
let fvk_encoding =
let open Data_encoding in
def "sapling.wallet.full_viewing_key"
@@ conv
(fun t -> (R.of_ak t.ak, R.of_nk t.nk, R.of_ovk t.ovk))
(fun (ak, nk, ovk) ->
{ak = R.to_ak ak; nk = R.to_nk nk; ovk = R.to_ovk ovk})
(obj3
(req "ak" (Fixed.bytes 32))
(req "nk" (Fixed.bytes 32))
(req "ovk" (Fixed.bytes 32)))
let of_expsk expsk =
{
ak = R.ask_to_ak Spending_key.(expsk.ask);
nk = R.nsk_to_nk Spending_key.(expsk.nsk);
ovk = expsk.ovk;
}
(** Type t additionally contains zip-32 related info *)
type t = R.zip32_full_viewing_key = {
depth : Bytes.t;
parent_fvk_tag : Bytes.t;
child_index : Bytes.t;
chain_code : Bytes.t;
fvk : full_viewing_key;
dk : Bytes.t;
}
let ovk_of_xfvk xfvk = xfvk.fvk.ovk
let encoding : t Data_encoding.t =
let open Data_encoding in
def "sapling.wallet.viewing_key"
@@ conv
(fun t ->
( t.depth,
t.parent_fvk_tag,
t.child_index,
t.chain_code,
t.fvk,
t.dk ))
(fun (depth, parent_fvk_tag, child_index, chain_code, fvk, dk) ->
{depth; parent_fvk_tag; child_index; chain_code; fvk; dk})
(obj6
(req "depth" (Fixed.bytes 1))
(req "parent_fvk_tag" (Fixed.bytes 4))
(req "child_index" (Fixed.bytes 4))
(req "chain_code" (Fixed.bytes 32))
(req "expsk" fvk_encoding)
(req "dk" (Fixed.bytes 32)))
let to_bytes = R.of_zip32_full_viewing_key
let of_bytes b = Option.catch (fun () -> R.to_zip32_full_viewing_key b)
let of_sk (sk : Spending_key.t) =
Spending_key.
{
depth = sk.depth;
parent_fvk_tag = sk.parent_fvk_tag;
child_index = sk.child_index;
chain_code = sk.chain_code;
fvk = of_expsk sk.expsk;
dk = sk.dk;
}
type index = R.diversifier_index
let compare_index = R.compare_diversifier_index
let index_to_int64 idx =
let b = R.of_diversifier_index idx in
assert (
Bytes.get b 8 = '\000'
&& Bytes.get b 9 = '\000'
&& Bytes.get b 10 = '\000') ;
Bytes.get_int64_le b 0
let index_of_int64 i =
let b = Bytes.make 11 '\000' in
Bytes.set_int64_le b 0 i ;
R.to_diversifier_index b
let index_encoding =
let open Data_encoding in
def "sapling.transaction.diversifier_index"
@@ conv index_to_int64 index_of_int64 int64
let default_index = index_of_int64 0L
let index_succ b = index_to_int64 b |> Int64.succ |> index_of_int64
type address = {diversifier : diversifier; pkd : pkd}
let address_encoding =
let open Data_encoding in
def "sapling.wallet.address"
@@ conv
(fun i -> (i.diversifier, R.of_pkd i.pkd))
(fun (diversifier, pkd) -> {diversifier; pkd = R.to_pkd pkd})
(obj2
(req "diversifier" diversifier_encoding)
(req "pkd" (Fixed.bytes 32)))
type Tezos_crypto.Base58.data += Data of address
let address_b58check_encoding =
let to_raw address =
Data_encoding.Binary.to_string_exn address_encoding address
in
let of_raw str =
Data_encoding.Binary.of_string_opt address_encoding str
in
Tezos_crypto.Base58.register_encoding
~prefix:Tezos_crypto.Base58.Prefix.sapling_address
~length:43
~to_raw
~of_raw
~wrap:(fun x -> Data x)
let () =
Tezos_crypto.Base58.check_encoded_prefix
address_b58check_encoding
"zet1"
69
let new_address vk j =
match R.zip32_xfvk_address vk j with
| None -> failwith "Exhausted available indices for the sapling key."
| Some (i, diversifier, pkd) -> (i, {diversifier; pkd})
let to_ivk xfvk = R.crh_ivk xfvk.fvk.ak xfvk.fvk.nk
let dummy_address () =
let rec random_diversifier () =
match R.to_diversifier @@ Tezos_crypto.Hacl.Rand.gen 11 with
| Some diversifier -> diversifier
| None -> random_diversifier ()
in
let diversifier = random_diversifier () in
let rand = Tezos_crypto.Hacl.Rand.gen 32 in
let mask = 0b00000111 in
let int = Char.code @@ Bytes.get rand (32 - 1) in
let int_masked = int land mask in
Bytes.set rand (32 - 1) (Char.chr int_masked) ;
let ivk = R.to_ivk rand in
let pkd = R.ivk_to_pkd ivk diversifier in
{diversifier; pkd}
end
(** See spec section 4.17 *)
module DH = struct
type esk = R.esk
let esk_encoding =
let open Data_encoding in
def "sapling.DH.esk" @@ conv R.of_esk R.to_esk (Fixed.bytes 32)
let esk_random () = R.to_esk @@ R.generate_r ()
type epk = R.epk
let epk_encoding =
let open Data_encoding in
def "sapling.DH.epk" @@ conv R.of_epk R.to_epk (Fixed.bytes 32)
(** Derives the public part of the DH for the sender.
(ie. epk is used for symkey_receiver). *)
let derive_ephemeral address esk =
R.ka_derivepublic Viewing_key.(address.diversifier) esk
let kdf_key = "KDFSaplingForTezosV1"
(** Derives a symmetric key to be used to create the ciphertext on the
sender side. *)
let symkey_sender esk pkd =
let symkey =
Bytes.unsafe_to_string @@ R.of_symkey @@ R.ka_agree_sender pkd esk
in
let hash =
Tezos_crypto.Blake2B.(to_bytes @@ hash_string ~key:kdf_key [symkey])
in
Tezos_crypto.Crypto_box.Secretbox.unsafe_of_bytes hash
let symkey_receiver epk ivk =
let symkey =
Bytes.unsafe_to_string @@ R.of_symkey @@ R.ka_agree_receiver epk ivk
in
let hash =
Tezos_crypto.Blake2B.(to_bytes @@ hash_string ~key:kdf_key [symkey])
in
Tezos_crypto.Crypto_box.Secretbox.unsafe_of_bytes hash
let symkey_out ovk (cv, cm, epk) =
let key = Bytes.of_string "OCK_keystringderivation_TEZOS" in
let ock =
Tezos_crypto.Blake2B.(
to_bytes
(hash_bytes
~key
[R.of_cv cv; R.of_commitment cm; R.of_epk epk; R.of_ovk ovk]))
in
Tezos_crypto.Crypto_box.Secretbox.unsafe_of_bytes ock
end
module Rcm = struct
type t = R.rcm
let random () = R.to_rcm @@ R.generate_r ()
let encoding =
let open Data_encoding in
def "sapling.transaction.rcm" @@ conv R.of_rcm R.to_rcm (Fixed.bytes 32)
let assert_valid =
let zeros = Bytes.make 32 '\000' in
fun rcm ->
assert (rcm = R.to_rcm (R.to_scalar (Bytes.cat (R.of_rcm rcm) zeros)))
end
module Commitment = struct
type t = R.commitment
let to_bytes = R.of_commitment
let of_bytes_exn = R.to_commitment
let encoding =
let open Data_encoding in
def "sapling.transaction.commitment"
@@ conv R.of_commitment R.to_commitment (Fixed.bytes 32)
let compute address ~amount rcm =
let open Viewing_key in
R.compute_cm address.diversifier address.pkd ~amount rcm
let valid_position = R.valid_position
end
module Nullifier = struct
type t = R.nullifier
let encoding =
let open Data_encoding in
def "sapling.transaction.nullifier"
@@ conv R.of_nullifier R.to_nullifier (Fixed.bytes 32)
let compare nf1 nf2 =
Bytes.compare (R.of_nullifier nf1) (R.of_nullifier nf2)
let compute address xfvk ~amount rcm ~position =
let open Viewing_key in
let pkd = R.ivk_to_pkd (to_ivk xfvk) address.diversifier in
R.compute_nf
address.diversifier
pkd
~amount
rcm
xfvk.fvk.ak
xfvk.fvk.nk
~position
end
module CV = struct
type t = R.cv
let of_bytes b = Option.catch (fun () -> R.to_cv b)
let encoding =
let open Data_encoding in
def "sapling.transaction.commitment_value"
@@ conv R.of_cv R.to_cv (Fixed.bytes 32)
end
module Ciphertext = struct
type t = {
cv : CV.t;
epk : DH.epk;
payload_enc : Bytes.t;
nonce_enc : Tezos_crypto.Crypto_box.nonce;
payload_out : Bytes.t;
nonce_out : Tezos_crypto.Crypto_box.nonce;
}
let encoding =
let open Data_encoding in
let payload_out_size =
Binary.(
(WithExceptions.Option.get ~loc:__LOC__
@@ fixed_length DH.esk_encoding)
+ (WithExceptions.Option.get ~loc:__LOC__
@@ fixed_length DH.epk_encoding)
+ Tezos_crypto.Crypto_box.tag_length)
in
def "sapling.transaction.ciphertext"
@@ conv
(fun o ->
( o.cv,
o.epk,
o.payload_enc,
o.nonce_enc,
o.payload_out,
o.nonce_out ))
(fun (cv, epk, payload_enc, nonce_enc, payload_out, nonce_out) ->
{cv; epk; payload_enc; nonce_enc; payload_out; nonce_out})
(obj6
(req "cv" CV.encoding)
(req "epk" DH.epk_encoding)
(req "payload_enc" bytes)
(req "nonce_enc" Tezos_crypto.Crypto_box.nonce_encoding)
(req "payload_out" (Fixed.bytes payload_out_size))
(req "nonce_out" Tezos_crypto.Crypto_box.nonce_encoding))
type plaintext = {
diversifier : Viewing_key.diversifier;
amount : int64;
rcm : Rcm.t;
memo : Bytes.t;
}
let plaintext_encoding =
let open Data_encoding in
def "sapling.transaction.plaintext"
@@ conv
(fun o ->
assert (R.valid_amount o.amount) ;
(o.diversifier, o.amount, o.rcm, o.memo))
(fun (diversifier, amount, rcm, memo) ->
assert (R.valid_amount amount) ;
{diversifier; amount; rcm; memo})
(obj4
(req "diversifier" Viewing_key.diversifier_encoding)
(req "amount" int64)
(req "rcm" Rcm.encoding)
(req "memo" bytes))
let get_memo_size ciphertext =
let payload_size = Bytes.length ciphertext.payload_enc in
let size_besides_memo =
let open Data_encoding in
(WithExceptions.Option.get ~loc:__LOC__
@@ Binary.fixed_length Viewing_key.diversifier_encoding)
+ (WithExceptions.Option.get ~loc:__LOC__ @@ Binary.fixed_length int64)
+ (WithExceptions.Option.get ~loc:__LOC__
@@ Binary.fixed_length Rcm.encoding)
+ Tezos_crypto.Crypto_box.tag_length + 4
in
payload_size - size_besides_memo
let decompose_plaintext_out plaintext =
assert (Bytes.length plaintext = 32 + 32) ;
let pkd = Bytes.create 32 in
let esk = Bytes.create 32 in
let () = Bytes.blit plaintext 0 pkd 0 32 in
let () = Bytes.blit plaintext 32 esk 0 32 in
(R.to_pkd pkd, R.to_esk esk)
let encrypt_aux key_agreed_out amount address rcm memo esk cv =
let epk = DH.derive_ephemeral address esk in
let nonce_enc = Tezos_crypto.Crypto_box.random_nonce () in
let payload_enc =
let key_agreed_enc = DH.symkey_sender esk address.pkd in
let plaintext_enc =
Data_encoding.Binary.to_bytes_exn
plaintext_encoding
{diversifier = Viewing_key.(address.diversifier); amount; rcm; memo}
in
Tezos_crypto.Crypto_box.Secretbox.secretbox
key_agreed_enc
plaintext_enc
nonce_enc
in
let nonce_out = Tezos_crypto.Crypto_box.random_nonce () in
let payload_out =
let plaintext_out =
Bytes.cat (R.of_pkd Viewing_key.(address.pkd)) (R.of_esk esk)
in
Tezos_crypto.Crypto_box.Secretbox.secretbox
key_agreed_out
plaintext_out
nonce_out
in
{epk; payload_enc; nonce_enc; payload_out; nonce_out; cv}
let encrypt amount address vk rcm memo (cv, cm, epk) esk =
let key_agreed_out =
DH.symkey_out Viewing_key.(vk.fvk.ovk) (cv, cm, epk)
in
encrypt_aux key_agreed_out amount address rcm memo esk cv
let encrypt_without_ovk amount address rcm memo esk cv =
let key_agreed_out =
Tezos_crypto.Crypto_box.Secretbox.unsafe_of_bytes
@@ Tezos_crypto.Hacl.Rand.gen 32
in
encrypt_aux key_agreed_out amount address rcm memo esk cv
let decrypt ciphertext xfvk =
let ivk = Viewing_key.to_ivk xfvk in
let symkey = DH.symkey_receiver ciphertext.epk ivk in
let ( >?? ) = Option.bind in
Tezos_crypto.Crypto_box.Secretbox.secretbox_open
symkey
ciphertext.payload_enc
ciphertext.nonce_enc
>?? fun plaintext ->
let {diversifier; amount; rcm; memo} =
Data_encoding.Binary.of_bytes_exn plaintext_encoding plaintext
in
let pkd = R.ivk_to_pkd ivk diversifier in
Some (Viewing_key.{pkd; diversifier}, amount, rcm, memo)
let decrypt_ovk ciphertext ovk (cm, epk) =
let symkey = DH.symkey_out ovk (ciphertext.cv, cm, epk) in
let ( >?? ) = Option.bind in
Tezos_crypto.Crypto_box.Secretbox.secretbox_open
symkey
ciphertext.payload_out
ciphertext.nonce_out
>?? fun plaintext ->
let pkd, esk = decompose_plaintext_out plaintext in
let symkey = DH.symkey_sender esk pkd in
Tezos_crypto.Crypto_box.Secretbox.secretbox_open
symkey
ciphertext.payload_enc
ciphertext.nonce_enc
>?? fun plaintext ->
let {diversifier; amount; rcm; memo} =
Data_encoding.Binary.of_bytes_exn plaintext_encoding plaintext
in
Some (Viewing_key.{pkd; diversifier}, amount, rcm, memo)
end
module Hash = struct
type t = R.hash
let compare = R.hash_compare
let encoding =
let open Data_encoding in
def "sapling.transaction.commitment_hash"
@@ conv R.of_hash R.to_hash (Fixed.bytes 32)
let merkle_hash = R.merkle_hash
let uncommitted_hashes =
lazy
(let max_height = 32 in
let res = Array.make (max_height + 1) R.tree_uncommitted in
for height = 0 to max_height - 1 do
let h = res.(height) in
res.(height + 1) <- R.merkle_hash ~height h h
done ;
res)
let uncommitted ~height = (Lazy.force uncommitted_hashes).(height)
let of_bytes_exn = R.to_hash
let to_bytes = R.of_hash
let of_commitment = R.hash_of_commitment
let to_commitment = R.commitment_of_hash
end
module UTXO = struct
type rk = R.rk
type spend_proof = R.spend_proof
(** What gets signed. Has to be a hash of an input plus anti-replay string. *)
type sighash = R.sighash
let hash_input cv nf rk proof key_string =
let key = Bytes.of_string key_string in
let h =
Tezos_crypto.Blake2B.(
to_bytes
(hash_bytes
~key
[
R.of_cv cv;
R.of_nullifier nf;
R.of_rk rk;
R.of_spend_proof proof;
]))
in
R.to_sighash h
type spend_sig = R.spend_sig
type input = {
cv : CV.t;
nf : Nullifier.t;
rk : rk;
proof_i : spend_proof;
signature : spend_sig;
}
let input_encoding =
let open Data_encoding in
let open R in
def "sapling.transaction.input" ~description:"Input of a transaction"
@@ conv
(fun i ->
( i.cv,
i.nf,
of_rk i.rk,
of_spend_proof i.proof_i,
of_spend_sig i.signature ))
(fun (cv, nf, rk, proof_i, signature) ->
{
cv;
nf;
rk = to_rk rk;
proof_i = to_spend_proof proof_i;
signature = to_spend_sig signature;
})
(obj5
(req "cv" CV.encoding)
(req "nf" Nullifier.encoding)
(req "rk" (Fixed.bytes 32))
(req "proof_i" (Fixed.bytes (48 + 96 + 48)))
(req "signature" (Fixed.bytes 64)))
type output_proof = R.output_proof
type output = {
cm : Commitment.t;
proof_o : output_proof;
ciphertext : Ciphertext.t;
}
let output_encoding =
let open Data_encoding in
let open R in
def "sapling.transaction.output" ~description:"Output of a transaction"
@@ conv
(fun o -> (o.cm, of_output_proof o.proof_o, o.ciphertext))
(fun (cm, proof_o, ciphertext) ->
{cm; proof_o = to_output_proof proof_o; ciphertext})
(obj3
(req "cm" Commitment.encoding)
(req "proof_o" (Fixed.bytes (48 + 96 + 48)))
(req "ciphertext" Ciphertext.encoding))
type binding_sig = R.binding_sig
let binding_sig_encoding =
let open Data_encoding in
def
"sapling.transaction.binding_sig"
~description:"Binding signature of a transaction"
@@ conv R.of_binding_sig R.to_binding_sig (Fixed.bytes 64)
let hash_transaction inputs outputs ~bound_data key =
let input_bytes =
List.map (Data_encoding.Binary.to_string_exn input_encoding) inputs
in
let output_bytes =
List.map (Data_encoding.Binary.to_string_exn output_encoding) outputs
in
let h =
Tezos_crypto.Blake2B.(
to_bytes
(hash_string ~key (input_bytes @ output_bytes @ [bound_data])))
in
R.to_sighash h
type transaction = {
inputs : input list;
outputs : output list;
binding_sig : binding_sig;
balance : int64;
root : Hash.t;
bound_data : string;
}
let transaction_encoding =
let open Data_encoding in
let check_memo_size outputs =
let size =
match outputs with
| o :: _ -> Ciphertext.get_memo_size o.ciphertext
| _ ->
-1
in
List.iter
(fun output ->
assert (Ciphertext.get_memo_size output.ciphertext = size))
outputs
in
def
"sapling.transaction"
~description:
"A Sapling transaction with inputs, outputs, balance, root, \
bound_data and binding sig."
@@ conv
(fun t ->
check_memo_size t.outputs ;
( t.inputs,
t.outputs,
t.binding_sig,
t.balance,
t.root,
t.bound_data ))
(fun (inputs, outputs, binding_sig, balance, root, bound_data) ->
check_memo_size outputs ;
{inputs; outputs; binding_sig; balance; root; bound_data})
(obj6
(req "inputs" (list ~max_length:5208 input_encoding))
(req "outputs" (list ~max_length:2019 output_encoding))
(req "binding_sig" binding_sig_encoding)
(req "balance" int64)
(req "root" Hash.encoding)
(req "bound_data" string))
let max_amount = R.max_amount
let valid_amount = R.valid_amount
module Legacy = struct
type transaction_new = transaction
type transaction = {
inputs : input list;
outputs : output list;
binding_sig : binding_sig;
balance : int64;
root : Hash.t;
}
let transaction_encoding =
let open Data_encoding in
let check_memo_size outputs =
let size =
match outputs with
| o :: _ -> Ciphertext.get_memo_size o.ciphertext
| _ ->
-1
in
List.iter
(fun output ->
assert (Ciphertext.get_memo_size output.ciphertext = size))
outputs
in
def
"sapling.transaction_legacy"
~description:
"A Sapling legacy transaction with inputs, outputs, balance, root \
and binding sig."
@@ conv
(fun t ->
check_memo_size t.outputs ;
(t.inputs, t.outputs, t.binding_sig, t.balance, t.root))
(fun (inputs, outputs, binding_sig, balance, root) ->
check_memo_size outputs ;
{inputs; outputs; binding_sig; balance; root})
(obj5
(req "inputs" (list ~max_length:5208 input_encoding))
(req "outputs" (list ~max_length:2019 output_encoding))
(req "binding_sig" binding_sig_encoding)
(req "balance" int64)
(req "root" Hash.encoding))
let cast : transaction -> transaction_new =
fun t ->
{
inputs = t.inputs;
outputs = t.outputs;
root = t.root;
binding_sig = t.binding_sig;
balance = t.balance;
bound_data = "";
}
end
end
module Proving = struct
type t = R.proving_ctx
type ar = R.ar
let with_proving_ctx = R.with_proving_ctx
let ar_random () = R.to_ar @@ R.generate_r ()
let spend_proof ctx xfvk xsp address rcm ar ~amount ~root ~witness =
let open Viewing_key in
R.spend_proof
ctx
xfvk.fvk.ak
Spending_key.(xsp.expsk.nsk)
address.diversifier
rcm
ar
~amount
~root
~witness
let spend_sig xsp ar cv nf rk proof key_string =
let sighash = UTXO.hash_input cv nf rk proof key_string in
R.spend_sig Spending_key.(xsp.expsk.ask) ar sighash
let output_proof ctx esk address rcm ~amount =
R.output_proof
ctx
esk
Viewing_key.(address.diversifier)
address.pkd
rcm
~amount
let make_binding_sig ctx inputs outputs ~balance ~bound_data key =
let sighash = UTXO.hash_transaction inputs outputs ~bound_data key in
R.make_binding_sig ctx ~balance sighash
end
module Verification = struct
type t = R.verification_ctx
let with_verification_ctx = R.with_verification_ctx
let check_spend ctx input root key =
let open UTXO in
let sighash = hash_input input.cv input.nf input.rk input.proof_i key in
R.check_spend
ctx
input.cv
root
input.nf
input.rk
input.proof_i
input.signature
sighash
let check_output ctx output =
let open UTXO in
R.check_output
ctx
output.ciphertext.cv
output.cm
output.ciphertext.epk
output.proof_o
let final_check ctx transaction key =
let open UTXO in
let hash =
hash_transaction
transaction.inputs
transaction.outputs
~bound_data:transaction.bound_data
key
in
R.final_check ctx transaction.balance transaction.binding_sig hash
end
module Forge = struct
module Input = struct
type t = {
rcm : Rcm.t;
pos : int64;
amount : int64;
address : Viewing_key.address;
}
let encoding =
let open Data_encoding in
def
"sapling.forge.input"
~description:"Data to forge the input of a transaction"
@@ conv
(fun i ->
assert (Commitment.valid_position i.pos) ;
assert (UTXO.valid_amount i.amount) ;
(i.rcm, i.pos, i.amount, i.address))
(fun (rcm, pos, amount, address) ->
assert (Commitment.valid_position pos) ;
assert (UTXO.valid_amount amount) ;
{rcm; pos; amount; address})
(obj4
(req "rcm" Rcm.encoding)
(req "pos" int64)
(req "amount" int64)
(req "addr" Viewing_key.address_encoding))
let compare fi1 fi2 =
let v = Int64.compare fi1.amount fi2.amount in
if v = 0 then Int64.compare fi1.pos fi2.pos else v
let of_ciphertext ~pos cipher vk =
Option.map
(fun (address, amount, rcm, memo) ->
(memo, {rcm; pos; amount; address}))
(Ciphertext.decrypt cipher vk)
let of_ciphertext_out ~pos cipher ovk cm =
let to_be_hashed = (cm, Ciphertext.(cipher.epk)) in
Option.map
(fun (address, amount, rcm, memo) ->
(memo, {rcm; pos; amount; address}))
(Ciphertext.decrypt_ovk cipher ovk to_be_hashed)
let check_cm i existing_cm =
Rcm.assert_valid i.rcm ;
let computed_cm = Commitment.compute i.address ~amount:i.amount i.rcm in
if existing_cm = computed_cm then true else false
end
module Output = struct
type t = {address : Viewing_key.address; amount : int64; memo : Bytes.t}
let to_ciphertext o cv vk rcm esk =
let cm = Commitment.compute o.address ~amount:o.amount rcm in
let epk = DH.derive_ephemeral o.address esk in
let to_be_hashed = (cv, cm, epk) in
let ciphertext =
Ciphertext.encrypt o.amount o.address vk rcm o.memo to_be_hashed esk
in
(ciphertext, cm)
let to_ciphertext_without_ovk o rcm esk cv =
let cm = Commitment.compute o.address ~amount:o.amount rcm in
let ciphertext =
Ciphertext.encrypt_without_ovk o.amount o.address rcm o.memo esk cv
in
(ciphertext, cm)
end
end
end
module Client : Core_sig.Client = Raw
module Validator :
Core_sig.Validator
with type Ciphertext.t = Client.Ciphertext.t
and type Commitment.t = Client.Commitment.t
and type CV.t = Client.CV.t
and type Hash.t = Client.Hash.t
and type Nullifier.t = Client.Nullifier.t
and module UTXO = Client.UTXO =
Client
module Validator_legacy = struct
include Validator
module UTXO = struct
include UTXO
include UTXO.Legacy
end
module Verification = struct
include Verification
let final_check ctx transaction key =
Validator.Verification.final_check
ctx
(Validator.UTXO.Legacy.cast transaction)
key
end
end
module Wallet :
Core_sig.Wallet
with type Spending_key.t = Client.Spending_key.t
and type Viewing_key.t = Client.Viewing_key.t
and type Viewing_key.address = Client.Viewing_key.address =
Client
let () =
Data_encoding.Registration.register Raw.Ciphertext.encoding ;
Data_encoding.Registration.register Raw.Ciphertext.plaintext_encoding ;
Data_encoding.Registration.register Raw.Commitment.encoding ;
Data_encoding.Registration.register Raw.CV.encoding ;
Data_encoding.Registration.register Raw.Hash.encoding ;
Data_encoding.Registration.register Raw.Nullifier.encoding ;
Data_encoding.Registration.register Raw.Rcm.encoding ;
Data_encoding.Registration.register Raw.Spending_key.encoding ;
Data_encoding.Registration.register Raw.UTXO.binding_sig_encoding ;
Data_encoding.Registration.register Raw.UTXO.input_encoding ;
Data_encoding.Registration.register Raw.UTXO.output_encoding ;
Data_encoding.Registration.register Raw.UTXO.transaction_encoding ;
Data_encoding.Registration.register Raw.Viewing_key.address_encoding ;
Data_encoding.Registration.register Raw.Viewing_key.index_encoding ;
Data_encoding.Registration.register Raw.Viewing_key.encoding