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Add Escrow support:

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Escrow replaces the existing SusPay implementation with improved
code that also adds hashlock support to escrow payments, making
RCL ILP enabled.

The new functionality is under the `Escrow` amendment, which
supersedes and replaces the `SusPay` amendment.

This commit also deprecates the `CryptoConditions` amendment
which is replaced by the `CryptoConditionSuite` amendment which,
once enabled, will allow use of cryptoconditions others than
hashlocks.
This commit is contained in:
Nik Bougalis
2017-02-28 07:45:05 -08:00
committed by seelabs
parent 0c97dda276
commit cfde591ac9
38 changed files with 1267 additions and 3705 deletions
Download Patch File Download Diff File Expand all files Collapse all files

520
src/ripple/app/tx/impl/Escrow.cpp Normal file
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//------------------------------------------------------------------------------
/*
This file is part of rippled: https://github.com/ripple/rippled
Copyright (c) 2012, 2013 Ripple Labs Inc.
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
#include <BeastConfig.h>
#include <ripple/app/tx/impl/Escrow.h>
#include <ripple/app/misc/HashRouter.h>
#include <ripple/basics/chrono.h>
#include <ripple/basics/Log.h>
#include <ripple/conditions/Condition.h>
#include <ripple/conditions/Fulfillment.h>
#include <ripple/protocol/digest.h>
#include <ripple/protocol/st.h>
#include <ripple/protocol/Feature.h>
#include <ripple/protocol/Indexes.h>
#include <ripple/protocol/TxFlags.h>
#include <ripple/protocol/XRPAmount.h>
#include <ripple/ledger/View.h>
// During an EscrowFinish, the transaction must specify both
// a condition and a fulfillment. We track whether that
// fulfillment matches and validates the condition.
#define SF_CF_INVALID SF_PRIVATE5
#define SF_CF_VALID SF_PRIVATE6
namespace ripple {
/*
Escrow allows an account holder to sequester any amount
of XRP in its own ledger entry, until the escrow process
either finishes or is canceled.
If the escrow process finishes successfully, then the
destination account (which must exist) will receives the
sequestered XRP. If the escrow is, instead, canceled,
the account which created the escrow will receive the
sequestered XRP back instead.
EscrowCreate
When an escrow is created, an optional condition may
be attached. If present, that condition must be
fulfilled for the escrow to successfully finish.
At the time of creation, one or both of the fields
sfCancelAfter and sfFinishAfter may be provided. If
neither field is specified, the transaction is
malformed.
Since the escrow eventually becomes a payment, an
optional DestinationTag and an optional SourceTag
are supported in the EscrowCreate transaction.
Validation rules:
sfCondition
If present, specifies a condition; the same
condition along with its matching fulfillment
are required during EscrowFinish.
sfCancelAfter
If present, escrow may be canceled after the
specified time (seconds after the Ripple epoch).
sfFinishAfter
If present, must be prior to sfCancelAfter.
A EscrowFinish succeeds only in ledgers after
sfFinishAfter but before sfCancelAfter.
If absent, same as parentCloseTime
Malformed if both sfCancelAfter, sfFinishAfter
are absent.
Malformed if both sfFinishAfter, sfCancelAfter
specified and sfCancelAfter <= sfFinishAfter
EscrowFinish
Any account may submit a EscrowFinish. If the escrow
ledger entry specifies a condition, the EscrowFinish
must provide the same condition and its associated
fulfillment in the sfCondition and sfFulfillment
fields, or else the EscrowFinish will fail.
If the escrow ledger entry specifies sfFinishAfter, the
transaction will fail if parentCloseTime <= sfFinishAfter.
EscrowFinish transactions must be submitted before
the escrow's sfCancelAfter if present.
If the escrow ledger entry specifies sfCancelAfter, the
transaction will fail if sfCancelAfter <= parentCloseTime.
NOTE: The reason the condition must be specified again
is because it must always be possible to verify
the condition without retrieving the escrow
ledger entry.
EscrowCancel
Any account may submit a EscrowCancel transaction.
If the escrow ledger entry does not specify a
sfCancelAfter, the cancel transaction will fail.
If parentCloseTime <= sfCancelAfter, the transaction
will fail.
When a escrow is canceled, the funds are returned to
the source account.
By careful selection of fields in each transaction,
these operations may be achieved:
* Lock up XRP for a time period
* Execute a payment conditionally
*/
//------------------------------------------------------------------------------
XRPAmount
EscrowCreate::calculateMaxSpend(STTx const& tx)
{
return tx[sfAmount].xrp();
}
TER
EscrowCreate::preflight (PreflightContext const& ctx)
{
if (! ctx.rules.enabled(featureEscrow))
return temDISABLED;
auto const ret = preflight1 (ctx);
if (!isTesSuccess (ret))
return ret;
if (! isXRP(ctx.tx[sfAmount]))
return temBAD_AMOUNT;
if (ctx.tx[sfAmount] <= beast::zero)
return temBAD_AMOUNT;
if (! ctx.tx[~sfCancelAfter] &&
! ctx.tx[~sfFinishAfter])
return temBAD_EXPIRATION;
if (ctx.tx[~sfCancelAfter] && ctx.tx[~sfFinishAfter] &&
ctx.tx[sfCancelAfter] <= ctx.tx[sfFinishAfter])
return temBAD_EXPIRATION;
if (auto const cb = ctx.tx[~sfCondition])
{
using namespace ripple::cryptoconditions;
std::error_code ec;
auto condition = Condition::deserialize(*cb, ec);
if (!condition)
{
JLOG(ctx.j.debug()) <<
"Malformed condition during escrow creation: " << ec.message();
return temMALFORMED;
}
// Conditions other than PrefixSha256 require the
// "CryptoConditionsSuite" amendment:
if (condition->type != Type::preimageSha256 &&
!ctx.rules.enabled(featureCryptoConditionsSuite))
return temDISABLED;
}
return preflight2 (ctx);
}
TER
EscrowCreate::doApply()
{
auto const closeTime = ctx_.view ().info ().parentCloseTime;
if (ctx_.tx[~sfCancelAfter])
{
auto const cancelAfter = ctx_.tx[sfCancelAfter];
if (closeTime.time_since_epoch().count() >= cancelAfter)
return tecNO_PERMISSION;
}
if (ctx_.tx[~sfFinishAfter])
{
auto const finishAfter = ctx_.tx[sfFinishAfter];
if (closeTime.time_since_epoch().count() >= finishAfter)
return tecNO_PERMISSION;
}
auto const account = ctx_.tx[sfAccount];
auto const sle = ctx_.view().peek(
keylet::account(account));
// Check reserve and funds availability
{
auto const balance = STAmount((*sle)[sfBalance]).xrp();
auto const reserve = ctx_.view().fees().accountReserve(
(*sle)[sfOwnerCount] + 1);
if (balance < reserve)
return tecINSUFFICIENT_RESERVE;
if (balance < reserve + STAmount(ctx_.tx[sfAmount]).xrp())
return tecUNFUNDED;
}
// Check destination account
{
auto const sled = ctx_.view().read(
keylet::account(ctx_.tx[sfDestination]));
if (! sled)
return tecNO_DST;
if (((*sled)[sfFlags] & lsfRequireDestTag) &&
! ctx_.tx[~sfDestinationTag])
return tecDST_TAG_NEEDED;
if ((*sled)[sfFlags] & lsfDisallowXRP)
return tecNO_TARGET;
}
// Create escrow in ledger
auto const slep = std::make_shared<SLE>(
keylet::escrow(account, (*sle)[sfSequence] - 1));
(*slep)[sfAmount] = ctx_.tx[sfAmount];
(*slep)[sfAccount] = account;
(*slep)[~sfCondition] = ctx_.tx[~sfCondition];
(*slep)[~sfSourceTag] = ctx_.tx[~sfSourceTag];
(*slep)[sfDestination] = ctx_.tx[sfDestination];
(*slep)[~sfCancelAfter] = ctx_.tx[~sfCancelAfter];
(*slep)[~sfFinishAfter] = ctx_.tx[~sfFinishAfter];
(*slep)[~sfDestinationTag] = ctx_.tx[~sfDestinationTag];
ctx_.view().insert(slep);
// Add escrow to owner directory
{
uint64_t page;
auto result = dirAdd(ctx_.view(), page,
keylet::ownerDir(account), slep->key(),
describeOwnerDir(account), ctx_.app.journal ("View"));
if (! isTesSuccess(result.first))
return result.first;
(*slep)[sfOwnerNode] = page;
}
// Deduct owner's balance, increment owner count
(*sle)[sfBalance] = (*sle)[sfBalance] - ctx_.tx[sfAmount];
(*sle)[sfOwnerCount] = (*sle)[sfOwnerCount] + 1;
ctx_.view().update(sle);
return tesSUCCESS;
}
//------------------------------------------------------------------------------
static
bool
checkCondition (Slice f, Slice c)
{
using namespace ripple::cryptoconditions;
std::error_code ec;
auto condition = Condition::deserialize(c, ec);
if (!condition)
return false;
auto fulfillment = Fulfillment::deserialize(f, ec);
if (!fulfillment)
return false;
return validate (*fulfillment, *condition);
}
TER
EscrowFinish::preflight (PreflightContext const& ctx)
{
if (! ctx.rules.enabled(featureEscrow))
return temDISABLED;
{
auto const ret = preflight1 (ctx);
if (!isTesSuccess (ret))
return ret;
}
auto const cb = ctx.tx[~sfCondition];
auto const fb = ctx.tx[~sfFulfillment];
// If you specify a condition, then you must also specify
// a fulfillment.
if (static_cast<bool>(cb) != static_cast<bool>(fb))
return temMALFORMED;
// Verify the transaction signature. If it doesn't work
// then don't do any more work.
{
auto const ret = preflight2 (ctx);
if (!isTesSuccess (ret))
return ret;
}
if (cb && fb)
{
auto& router = ctx.app.getHashRouter();
auto const id = ctx.tx.getTransactionID();
auto const flags = router.getFlags (id);
// If we haven't checked the condition, check it
// now. Whether it passes or not isn't important
// in preflight.
if (!(flags & (SF_CF_INVALID | SF_CF_VALID)))
{
if (checkCondition (*fb, *cb))
router.setFlags (id, SF_CF_VALID);
else
router.setFlags (id, SF_CF_INVALID);
}
}
return tesSUCCESS;
}
std::uint64_t
EscrowFinish::calculateBaseFee (PreclaimContext const& ctx)
{
std::uint64_t extraFee = 0;
if (auto const fb = ctx.tx[~sfFulfillment])
{
extraFee += ctx.view.fees().units *
(32 + static_cast<std::uint64_t> (fb->size() / 16));
}
return Transactor::calculateBaseFee (ctx) + extraFee;
}
TER
EscrowFinish::doApply()
{
auto const k = keylet::escrow(
ctx_.tx[sfOwner], ctx_.tx[sfOfferSequence]);
auto const slep = ctx_.view().peek(k);
if (! slep)
return tecNO_TARGET;
// Too soon?
if ((*slep)[~sfFinishAfter] &&
ctx_.view().info().parentCloseTime.time_since_epoch().count() <=
(*slep)[sfFinishAfter])
return tecNO_PERMISSION;
// Too late?
if ((*slep)[~sfCancelAfter] &&
(*slep)[sfCancelAfter] <=
ctx_.view().info().parentCloseTime.time_since_epoch().count())
return tecNO_PERMISSION;
// Check cryptocondition fulfillment
{
auto const id = ctx_.tx.getTransactionID();
auto flags = ctx_.app.getHashRouter().getFlags (id);
auto const cb = ctx_.tx[~sfCondition];
// It's unlikely that the results of the check will
// expire from the hash router, but if it happens,
// simply re-run the check.
if (cb && ! (flags & (SF_CF_INVALID | SF_CF_VALID)))
{
auto const fb = ctx_.tx[~sfFulfillment];
if (!fb)
return tecINTERNAL;
if (checkCondition (*fb, *cb))
flags = SF_CF_VALID;
else
flags = SF_CF_INVALID;
ctx_.app.getHashRouter().setFlags (id, flags);
}
// If the check failed, then simply return an error
// and don't look at anything else.
if (flags & SF_CF_INVALID)
return tecCRYPTOCONDITION_ERROR;
// Check against condition in the ledger entry:
auto const cond = (*slep)[~sfCondition];
// If a condition wasn't specified during creation,
// one shouldn't be included now.
if (!cond && cb)
return tecCRYPTOCONDITION_ERROR;
// If a condition was specified during creation of
// the suspended payment, the identical condition
// must be presented again. We don't check if the
// fulfillment matches the condition since we did
// that in preflight.
if (cond && (cond != cb))
return tecCRYPTOCONDITION_ERROR;
}
AccountID const account = (*slep)[sfAccount];
// Remove escrow from owner directory
{
auto const page = (*slep)[sfOwnerNode];
TER const ter = dirDelete(ctx_.view(), true,
page, keylet::ownerDir(account).key,
k.key, false, page == 0, ctx_.app.journal ("View"));
if (! isTesSuccess(ter))
return ter;
}
// NOTE: These payments cannot be used to fund accounts
// Fetch Destination SLE
auto const sled = ctx_.view().peek(
keylet::account((*slep)[sfDestination]));
if (! sled)
return tecNO_DST;
// Transfer amount to destination
(*sled)[sfBalance] = (*sled)[sfBalance] + (*slep)[sfAmount];
ctx_.view().update(sled);
// Adjust source owner count
auto const sle = ctx_.view().peek(
keylet::account(account));
(*sle)[sfOwnerCount] = (*sle)[sfOwnerCount] - 1;
ctx_.view().update(sle);
// Remove escrow from ledger
ctx_.view().erase(slep);
return tesSUCCESS;
}
//------------------------------------------------------------------------------
TER
EscrowCancel::preflight (PreflightContext const& ctx)
{
if (! ctx.rules.enabled(featureEscrow))
return temDISABLED;
auto const ret = preflight1 (ctx);
if (!isTesSuccess (ret))
return ret;
return preflight2 (ctx);
}
TER
EscrowCancel::doApply()
{
auto const k = keylet::escrow(
ctx_.tx[sfOwner], ctx_.tx[sfOfferSequence]);
auto const slep = ctx_.view().peek(k);
if (! slep)
return tecNO_TARGET;
// Too soon?
if (! (*slep)[~sfCancelAfter] ||
ctx_.view().info().parentCloseTime.time_since_epoch().count() <=
(*slep)[sfCancelAfter])
return tecNO_PERMISSION;
AccountID const account = (*slep)[sfAccount];
// Remove escrow from owner directory
{
auto const page = (*slep)[sfOwnerNode];
TER const ter = dirDelete(ctx_.view(), true,
page, keylet::ownerDir(account).key,
k.key, false, page == 0, ctx_.app.journal ("View"));
if (! isTesSuccess(ter))
return ter;
}
// Transfer amount back to owner, decrement owner count
auto const sle = ctx_.view().peek(
keylet::account(account));
(*sle)[sfBalance] = (*sle)[sfBalance] + (*slep)[sfAmount];
(*sle)[sfOwnerCount] = (*sle)[sfOwnerCount] - 1;
ctx_.view().update(sle);
// Remove escrow from ledger
ctx_.view().erase(slep);
return tesSUCCESS;
}
} // ripple