Files
hush3/src/komodo_cryptoconditions.cpp
2018-03-12 01:57:35 -03:00

102 lines
3.2 KiB
C++

#include "replacementpool.h"
#include "komodo_cryptoconditions.h"
#include "cryptoconditions/include/cryptoconditions.h"
bool ASSETCHAINS_CC_TEST = false;
/*
* Evaluate the validity of an Eval node
*/
bool EvalConditionValidity(const CC *cond, const CTransaction *txTo)
{
if (ASSETCHAINS_CC_TEST) {
if (strcmp(cond->method, "testEval") == 0) {
return cond->paramsBinLength == 8 &&
memcmp(cond->paramsBin, "testEval", 8) == 0;
}
if (strcmp(cond->method, "testReplace") == 0) {
std::vector<unsigned char> data;
auto out = txTo->vout[txTo->vout.size()-1]; // Last output is data
return GetOpReturnData(out.scriptPubKey, data) && data.size() == 2;
}
}
fprintf(stderr, "no defined behaviour for method: %s\n", cond->method);
return 0;
}
/*
* Evaluate the priority of an eval node.
*
* This method should set the ->priority and ->replacementWindow (in blocks)
* of the provided replacement pool item. Priority is a 64 bit unsigned int and
* 0 is invalid.
*
* This method does not need to validate, that is done separately. Actually,
* this method will nearly always be called with the same condition and transaction
* in sequence after EvalConditionValidity. If performance became an issue, a very
* small LRU cache could be used to cache a result.
*/
bool EvalConditionPriority(const CC *cond, CTxReplacementPoolItem *rep)
{
if (ASSETCHAINS_CC_TEST) {
if (strcmp((const char*)cond->method, "testReplace") == 0) {
std::vector<unsigned char> data;
auto out = rep->tx.vout[rep->tx.vout.size()-1]; // Last output is data
if (GetOpReturnData(out.scriptPubKey, data)) {
rep->replacementWindow = (int) data[0];
rep->priority = (uint64_t) data[1];
return true;
}
}
}
return false;
}
int visitConditionPriority(CC *cond, struct CCVisitor visitor)
{
auto rep = (CTxReplacementPoolItem*)visitor.context;
// visitor protocol is 1 for continue, 0 for stop
return !(cc_typeId(cond) == CC_Eval && EvalConditionPriority(cond, rep));
}
/*
* Try to get replacement parameters from a transaction in &rep.
*/
bool SetReplacementParams(CTxReplacementPoolItem &rep)
{
// first, see if we have a cryptocondition
const CScript &sig = rep.tx.vin[0].scriptSig;
if (!sig.IsPushOnly()) return false;
CScript::const_iterator pc = sig.begin();
std::vector<unsigned char> data;
opcodetype opcode;
if (!sig.GetOp(pc, opcode, data)) return false;
CC *cond = cc_readFulfillmentBinary((unsigned char*)data.data(), data.size());
if (!cond) return false;
// now, see if it has a replacement node
CC *replacementNode = 0;
CCVisitor visitor = {&visitConditionPriority, (const unsigned char*)"", 0, &rep};
bool out = cc_visit(cond, visitor);
cc_free(cond);
return !out;
}
bool GetOpReturnData(const CScript &sig, std::vector<unsigned char> &data)
{
auto pc = sig.begin();
opcodetype opcode;
if (sig.GetOp(pc, opcode))
if (opcode == OP_RETURN)
if (sig.GetOp(pc, opcode, data))
return opcode > OP_0 && opcode <= OP_PUSHDATA4;
return false;
}