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authorGavin Andresen <gavinandresen@gmail.com>2011-09-28 12:30:06 -0400
committerGavin Andresen <gavinandresen@gmail.com>2011-12-19 12:40:19 -0500
commitbf798734db4539a39edd6badf54a1c3aecf193e5 (patch)
tree850f60c149335de2c85c0aafd10a8fc50aca9c7e /src/script.cpp
parent1466b8b78ad8cabf93ac3f65f5929213c5dd3c8f (diff)
Support 3 new multisignature IsStandard transactions
Initial support for (a and b), (a or b), and 2-of-3 escrow transactions (where a, b, and c are keys).
Diffstat (limited to 'src/script.cpp')
-rw-r--r--src/script.cpp223
1 files changed, 156 insertions, 67 deletions
diff --git a/src/script.cpp b/src/script.cpp
index 4b2dc9a1a6..6a7913b0d5 100644
--- a/src/script.cpp
+++ b/src/script.cpp
@@ -963,8 +963,11 @@ bool CheckSig(vector<unsigned char> vchSig, vector<unsigned char> vchPubKey, CSc
-
-bool Solver(const CScript& scriptPubKey, vector<pair<opcodetype, valtype> >& vSolutionRet)
+//
+// Returns lists of public keys (or public key hashes), any one of which can
+// satisfy scriptPubKey
+//
+bool Solver(const CScript& scriptPubKey, vector<vector<pair<opcodetype, valtype> > >& vSolutionsRet)
{
// Templates
static vector<CScript> vTemplates;
@@ -975,13 +978,24 @@ bool Solver(const CScript& scriptPubKey, vector<pair<opcodetype, valtype> >& vSo
// Bitcoin address tx, sender provides hash of pubkey, receiver provides signature and pubkey
vTemplates.push_back(CScript() << OP_DUP << OP_HASH160 << OP_PUBKEYHASH << OP_EQUALVERIFY << OP_CHECKSIG);
+
+ // Sender provides two pubkeys, receivers provides two signatures
+ vTemplates.push_back(CScript() << OP_2 << OP_PUBKEY << OP_PUBKEY << OP_2 << OP_CHECKMULTISIG);
+
+ // Sender provides two pubkeys, receivers provides one of two signatures
+ vTemplates.push_back(CScript() << OP_1 << OP_PUBKEY << OP_PUBKEY << OP_2 << OP_CHECKMULTISIG);
+
+ // Sender provides three pubkeys, receiver provides 2 of 3 signatures.
+ vTemplates.push_back(CScript() << OP_2 << OP_PUBKEY << OP_PUBKEY << OP_PUBKEY << OP_3 << OP_CHECKMULTISIG);
}
// Scan templates
const CScript& script1 = scriptPubKey;
BOOST_FOREACH(const CScript& script2, vTemplates)
{
- vSolutionRet.clear();
+ vSolutionsRet.clear();
+
+ vector<pair<opcodetype, valtype> > currentSolution;
opcodetype opcode1, opcode2;
vector<unsigned char> vch1, vch2;
@@ -992,9 +1006,7 @@ bool Solver(const CScript& scriptPubKey, vector<pair<opcodetype, valtype> >& vSo
{
if (pc1 == script1.end() && pc2 == script2.end())
{
- // Found a match
- reverse(vSolutionRet.begin(), vSolutionRet.end());
- return true;
+ return !vSolutionsRet.empty();
}
if (!script1.GetOp(pc1, opcode1, vch1))
break;
@@ -1004,13 +1016,54 @@ bool Solver(const CScript& scriptPubKey, vector<pair<opcodetype, valtype> >& vSo
{
if (vch1.size() < 33 || vch1.size() > 120)
break;
- vSolutionRet.push_back(make_pair(opcode2, vch1));
+ currentSolution.push_back(make_pair(opcode2, vch1));
}
else if (opcode2 == OP_PUBKEYHASH)
{
if (vch1.size() != sizeof(uint160))
break;
- vSolutionRet.push_back(make_pair(opcode2, vch1));
+ currentSolution.push_back(make_pair(opcode2, vch1));
+ }
+ else if (opcode2 == OP_CHECKSIG)
+ {
+ vSolutionsRet.push_back(currentSolution);
+ currentSolution.clear();
+ }
+ else if (opcode2 == OP_CHECKMULTISIG)
+ { // Dig out the "m" from before the pubkeys:
+ CScript::const_iterator it = script2.begin();
+ opcodetype op_m;
+ script2.GetOp(it, op_m, vch1);
+ int m = CScript::DecodeOP_N(op_m);
+ int n = currentSolution.size();
+
+ if (m == 2 && n == 2)
+ {
+ vSolutionsRet.push_back(currentSolution);
+ currentSolution.clear();
+ }
+ else if (m == 1 && n == 2)
+ { // 2 solutions: either first key or second
+ for (int i = 0; i < 2; i++)
+ {
+ vector<pair<opcodetype, valtype> > s;
+ s.push_back(currentSolution[i]);
+ vSolutionsRet.push_back(s);
+ }
+ currentSolution.clear();
+ }
+ else if (m == 2 && n == 3)
+ { // 3 solutions: any pair
+ for (int i = 0; i < 2; i++)
+ for (int j = i+1; j < 3; j++)
+ {
+ vector<pair<opcodetype, valtype> > s;
+ s.push_back(currentSolution[i]);
+ s.push_back(currentSolution[j]);
+ vSolutionsRet.push_back(s);
+ }
+ currentSolution.clear();
+ }
}
else if (opcode1 != opcode2 || vch1 != vch2)
{
@@ -1019,7 +1072,7 @@ bool Solver(const CScript& scriptPubKey, vector<pair<opcodetype, valtype> >& vSo
}
}
- vSolutionRet.clear();
+ vSolutionsRet.clear();
return false;
}
@@ -1028,51 +1081,61 @@ bool Solver(const CKeyStore& keystore, const CScript& scriptPubKey, uint256 hash
{
scriptSigRet.clear();
- vector<pair<opcodetype, valtype> > vSolution;
- if (!Solver(scriptPubKey, vSolution))
+ vector<vector<pair<opcodetype, valtype> > > vSolutions;
+ if (!Solver(scriptPubKey, vSolutions))
return false;
- // Compile solution
- BOOST_FOREACH(PAIRTYPE(opcodetype, valtype)& item, vSolution)
+ // See if we have all the keys for any of the solutions:
+ int whichSolution = -1;
+ for (int i = 0; i < vSolutions.size(); i++)
{
- if (item.first == OP_PUBKEY)
+ int keysFound = 0;
+ CScript scriptSig;
+
+ BOOST_FOREACH(PAIRTYPE(opcodetype, valtype)& item, vSolutions[i])
{
- // Sign
- const valtype& vchPubKey = item.second;
- CKey key;
- if (!keystore.GetKey(Hash160(vchPubKey), key))
- return false;
- if (key.GetPubKey() != vchPubKey)
- return false;
- if (hash != 0)
+ if (item.first == OP_PUBKEY)
{
+ const valtype& vchPubKey = item.second;
+ CKey key;
vector<unsigned char> vchSig;
- if (!key.Sign(hash, vchSig))
- return false;
- vchSig.push_back((unsigned char)nHashType);
- scriptSigRet << vchSig;
+ if (keystore.GetKey(Hash160(vchPubKey), key) && key.GetPubKey() == vchPubKey
+ && hash != 0 && key.Sign(hash, vchSig))
+ {
+ vchSig.push_back((unsigned char)nHashType);
+ scriptSig << vchSig;
+ ++keysFound;
+ }
}
- }
- else if (item.first == OP_PUBKEYHASH)
- {
- // Sign and give pubkey
- CKey key;
- if (!keystore.GetKey(uint160(item.second), key))
- return false;
- if (hash != 0)
+ else if (item.first == OP_PUBKEYHASH)
{
+ CKey key;
vector<unsigned char> vchSig;
- if (!key.Sign(hash, vchSig))
- return false;
- vchSig.push_back((unsigned char)nHashType);
- scriptSigRet << vchSig << key.GetPubKey();
+ if (keystore.GetKey(uint160(item.second), key)
+ && hash != 0 && key.Sign(hash, vchSig))
+ {
+ vchSig.push_back((unsigned char)nHashType);
+ scriptSig << vchSig << key.GetPubKey();
+ ++keysFound;
+ }
}
}
- else
+ if (keysFound == vSolutions[i].size())
{
- return false;
+ whichSolution = i;
+ scriptSigRet = scriptSig;
+ break;
}
}
+ if (whichSolution == -1)
+ return false;
+
+ // CHECKMULTISIG bug workaround:
+ if (vSolutions.size() != 1 ||
+ vSolutions[0].size() != 1)
+ {
+ scriptSigRet.insert(scriptSigRet.begin(), OP_0);
+ }
return true;
}
@@ -1080,51 +1143,59 @@ bool Solver(const CKeyStore& keystore, const CScript& scriptPubKey, uint256 hash
bool IsStandard(const CScript& scriptPubKey)
{
- vector<pair<opcodetype, valtype> > vSolution;
- return Solver(scriptPubKey, vSolution);
+ vector<vector<pair<opcodetype, valtype> > > vSolutions;
+ return Solver(scriptPubKey, vSolutions);
}
bool IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
{
- vector<pair<opcodetype, valtype> > vSolution;
- if (!Solver(scriptPubKey, vSolution))
+ vector<vector<pair<opcodetype, valtype> > > vSolutions;
+ if (!Solver(scriptPubKey, vSolutions))
return false;
- // Compile solution
- BOOST_FOREACH(PAIRTYPE(opcodetype, valtype)& item, vSolution)
+ int keysFound = 0;
+ int keysRequired = 0;
+ for (int i = 0; i < vSolutions.size(); i++)
{
- if (item.first == OP_PUBKEY)
- {
- const valtype& vchPubKey = item.second;
- vector<unsigned char> vchPubKeyFound;
- if (!keystore.GetPubKey(Hash160(vchPubKey), vchPubKeyFound))
- return false;
- if (vchPubKeyFound != vchPubKey)
- return false;
- }
- else if (item.first == OP_PUBKEYHASH)
- {
- if (!keystore.HaveKey(uint160(item.second)))
- return false;
- }
- else
+ BOOST_FOREACH(PAIRTYPE(opcodetype, valtype)& item, vSolutions[i])
{
- return false;
+ ++keysRequired;
+ if (item.first == OP_PUBKEY)
+ {
+ const valtype& vchPubKey = item.second;
+ vector<unsigned char> vchPubKeyFound;
+ if (keystore.GetPubKey(Hash160(vchPubKey), vchPubKeyFound) && vchPubKeyFound == vchPubKey)
+ ++keysFound;
+ }
+ else if (item.first == OP_PUBKEYHASH)
+ {
+ if (keystore.HaveKey(uint160(item.second)))
+ ++keysFound;
+ }
}
}
- return true;
+ // Only consider transactions "mine" if we own ALL the
+ // keys involved. multi-signature transactions that are
+ // partially owned (somebody else has a key that can spend
+ // them) enable spend-out-from-under-you attacks, especially
+ // for shared-wallet situations.
+ return (keysFound == keysRequired);
}
bool ExtractAddress(const CScript& scriptPubKey, const CKeyStore* keystore, CBitcoinAddress& addressRet)
{
- vector<pair<opcodetype, valtype> > vSolution;
- if (!Solver(scriptPubKey, vSolution))
+ vector<vector<pair<opcodetype, valtype> > > vSolutions;
+ if (!Solver(scriptPubKey, vSolutions))
return false;
- BOOST_FOREACH(PAIRTYPE(opcodetype, valtype)& item, vSolution)
+ for (int i = 0; i < vSolutions.size(); i++)
{
+ if (vSolutions[i].size() != 1)
+ continue; // Can't return more than one address...
+
+ PAIRTYPE(opcodetype, valtype)& item = vSolutions[i][0];
if (item.first == OP_PUBKEY)
addressRet.SetPubKey(item.second);
else if (item.first == OP_PUBKEYHASH)
@@ -1132,7 +1203,6 @@ bool ExtractAddress(const CScript& scriptPubKey, const CKeyStore* keystore, CBit
if (keystore == NULL || keystore->HaveKey(addressRet))
return true;
}
-
return false;
}
@@ -1192,3 +1262,22 @@ bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsig
return true;
}
+
+void CScript::SetMultisigAnd(const std::vector<CKey>& keys)
+{
+ assert(keys.size() >= 2);
+ this->clear();
+ *this << OP_2 << keys[0].GetPubKey() << keys[1].GetPubKey() << OP_2 << OP_CHECKMULTISIG;
+}
+void CScript::SetMultisigOr(const std::vector<CKey>& keys)
+{
+ assert(keys.size() >= 2);
+ this->clear();
+ *this << OP_1 << keys[0].GetPubKey() << keys[1].GetPubKey() << OP_2 << OP_CHECKMULTISIG;
+}
+void CScript::SetMultisigEscrow(const std::vector<CKey>& keys)
+{
+ assert(keys.size() >= 3);
+ this->clear();
+ *this << OP_2 << keys[0].GetPubKey() << keys[1].GetPubKey() << keys[1].GetPubKey() << OP_3 << OP_CHECKMULTISIG;
+}