parameter (or (unit %default)
(pair %main
(pair :payload
(nat %counter) # counter, used to prevent replay attacks
(or :action # payload to sign, represents the requested action
(lambda %operation unit (list operation))
(pair %change_keys # change the keys controlling the multisig
(nat %threshold) # new threshold
(list %keys key)))) # new list of keys
(list %sigs (option signature)))); # signatures
storage (pair (nat %stored_counter) (pair (nat %threshold) (list %keys key))) ;
code
{
UNPAIR ;
IF_LEFT
{ # Default entry point: do nothing
# This entry point can be used to send tokens to this contract
DROP ; NIL operation ; PAIR }
{ # Main entry point
# Assert no token was sent:
# to send tokens, the default entry point should be used
PUSH mutez 0 ; AMOUNT ; ASSERT_CMPEQ ;
SWAP ; DUP ; DIP { SWAP } ;
DIP
{
UNPAIR ;
# pair the payload with the current contract address, to ensure signatures
# can't be replayed accross different contracts if a key is reused.
DUP ; SELF ; ADDRESS ; CHAIN_ID ; PAIR ; PAIR ;
PACK ; # form the binary payload that we expect to be signed
DIP { UNPAIR @counter ; DIP { SWAP } } ; SWAP
} ;
# Check that the counters match
UNPAIR @stored_counter; DIP { SWAP };
ASSERT_CMPEQ ;
# Compute the number of valid signatures
DIP { SWAP } ; UNPAIR @threshold @keys;
DIP
{
# Running count of valid signatures
PUSH @valid nat 0; SWAP ;
ITER
{
DIP { SWAP } ; SWAP ;
IF_CONS
{
IF_SOME
{ SWAP ;
DIP
{
SWAP ; DIIP { DUUP } ;
# Checks signatures, fails if invalid
{ DUUUP; DIP {CHECK_SIGNATURE}; SWAP; IF {DROP} {FAILWITH} };
PUSH nat 1 ; ADD @valid } }
{ SWAP ; DROP }
}
{
# There were fewer signatures in the list
# than keys. Not all signatures must be present, but
# they should be marked as absent using the option type.
FAIL
} ;
SWAP
}
} ;
# Assert that the threshold is less than or equal to the
# number of valid signatures.
ASSERT_CMPLE ;
# Assert no unchecked signature remains
IF_CONS {FAIL} {} ;
DROP ;
# Increment counter and place in storage
DIP { UNPAIR ; PUSH nat 1 ; ADD @new_counter ; PAIR} ;
# We have now handled the signature verification part,
# produce the operation requested by the signers.
IF_LEFT
{ # Get operation
UNIT ; EXEC
}
{
# Change set of signatures
DIP { CAR } ; SWAP ; PAIR ; NIL operation
};
PAIR }
}
open SCamltype storage = { stored_counter : nat ; threshold : nat ; keys : key list }type parameter = { payload : payload ; sigs : signature optionlist }and payload = { counter : nat ; action : action }and action = | Transfer of transfer | Delegate of key_hash option | Change_keys of change_keysand transfer = { amount : tz ; dest : unit contract }and change_keys = { threshold : nat ; keys : key list }let main parameter storage =(* pair the payload with the current contract address, to ensure signatures can't be replayed accross different contracts if a key is reused. *)let signature_target = Obj.pack ( parameter.payload , Contract.address Contract.self , (match (Obj.unpack (Obj.pack (Chain_id "NetXdQprcVkpaWU")) : SCaml.chain_id option) withNone -> failwith"failed" | Some x -> x)(* Global.get_chain_id () varies in different networks *) )in(* Check that the counters *)assert (storage.stored_counter = parameter.payload.counter);(* Compute the number of valid signatures *)let nsigs = Loop.left (fun (nsigs, keys, sigs) ->match keys, sigs with | [], [] -> Right nsigs | key::keys, Some sig_::sigs ->(* Checks signatures, fails if invalid *)assert (Crypto.check_signature key sig_ signature_target); Left (nsigs +^ Nat 1, keys, sigs) | key::keys, None::sigs -> Left (nsigs, keys, sigs) | _ ->(* There were fewer signatures in the list than keys. Not all signatures must be present, but they should be marked as absent using the option type. *)assertfalse ) (Nat 0, storage.keys, parameter.sigs)in(* Assert that the threshold is less than or equal to the number of valid signatures. *)assert (storage.threshold <= nsigs);(* Increment counter and place in storage *)let storage = { storage with stored_counter = storage.stored_counter +^ Nat 1 } in(* We have now handled the signature verification part, produce the operation requested by the signers. *)match parameter.payload.action with | Transfer { amount ; dest } -> (* Transfer tokens *) [ Operation.transfer_tokens () amount dest ], storage | Delegate key_hash_opt -> (* Change delegate *) [ Operation.set_delegate key_hash_opt], storage | Change_keys { threshold ; keys } -> (* Change set of signatures *) [], { storage with threshold; keys }
# 匿名アカウント作成
$ tezos-client sapling gen key <zname>
# 使用するスマートコントラクトを指定
$ tezos-client sapling use key <zname> for contract <contract>
# 匿名アドレスを作成
$ tezos-client sapling gen address <zname>
# 通常アカウントから匿名アドレスへの送金 1 tez = 1 shielded tez
$ tezos-client sapling shield <amount> from <name> to <zaddress>
# 匿名アドレスの残高照会
$ tezos-client sapling get balance for <zname> in contract <contract>
# 匿名送金の作成
$ tezos-client sapling forge transaction <amount> from <zname> to <zaddress> \
using <contract>
# 送金命令の送信
$ tezos-client sapling submit <file> from <account> using <contract>
GUIウォレットへの対応が待たれる
Sapling in Michelson
type n sapling_state (* 状態。 n は整数定数 *)type n sapling_transaction (* 状態変更 *)val SAPLING_EMPTY_STATE n : n sapling_state(** 空の状態 *)val SAPLING_VERIFY_UPDATE n : n sapling_transaction -> n sapling_state -> (int * n sapling_state) option(** State の元で transaction が valid であれば、 transaction を適用して新しい state を返す *)
