Function Solver

src/script/standard.cpp:62–295

* Return public keys or hashes from scriptPubKey, for 'standard' transaction types. */

 * Return public keys or hashes from scriptPubKey, for 'standard' transaction types.
 */
bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsigned char> >& vSolutionsRet, bool contractConsensus)
{
    //contractConsesus is true when evaluating if a contract tx is "standard" for consensus purposes
    //It is false in all other cases, so to prevent a particular contract tx from being broadcast on mempool, but allowed in blocks,
    //one should ensure that contractConsensus is false

    // Templates
    static multimap<txnouttype, CScript> mTemplates;
    if (mTemplates.empty())
    {
        // Standard tx, sender provides pubkey, receiver adds signature
        mTemplates.insert(make_pair(TX_PUBKEY, CScript() << OP_PUBKEY << OP_CHECKSIG));

        // Bitcoin address tx, sender provides hash of pubkey, receiver provides signature and pubkey
        mTemplates.insert(make_pair(TX_PUBKEYHASH, CScript() << OP_DUP << OP_HASH160 << OP_PUBKEYHASH << OP_EQUALVERIFY << OP_CHECKSIG));

        // Sender provides N pubkeys, receivers provides M signatures
        mTemplates.insert(make_pair(TX_MULTISIG, CScript() << OP_SMALLINTEGER << OP_PUBKEYS << OP_SMALLINTEGER << OP_CHECKMULTISIG));

        // Contract creation tx
        mTemplates.insert(make_pair(TX_CREATE, CScript() << OP_VERSION << OP_GAS_LIMIT << OP_GAS_PRICE << OP_DATA << OP_CREATE));

        // Call contract tx
        mTemplates.insert(make_pair(TX_CALL, CScript() << OP_VERSION << OP_GAS_LIMIT << OP_GAS_PRICE << OP_DATA << OP_PUBKEYHASH << OP_CALL));
//        // Empty, provably prunable, data-carrying output
//        if (GetBoolArg("-datacarrier", true))
//            mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN << OP_SMALLDATA));
        mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN));
    }

    vSolutionsRet.clear();

    // Shortcut for pay-to-script-hash, which are more constrained than the other types:
    // it is always OP_HASH160 20 [20 byte hash] OP_EQUAL
    if (scriptPubKey.IsPayToScriptHash())
    {
        typeRet = TX_SCRIPTHASH;
        vector<unsigned char> hashBytes(scriptPubKey.begin()+2, scriptPubKey.begin()+22);
        vSolutionsRet.push_back(hashBytes);
        return true;
    }

    int witnessversion;
    std::vector<unsigned char> witnessprogram;
    if (scriptPubKey.IsWitnessProgram(witnessversion, witnessprogram)) {
        if (witnessversion == 0 && witnessprogram.size() == 20) {
            typeRet = TX_WITNESS_V0_KEYHASH;
            vSolutionsRet.push_back(witnessprogram);
            return true;
        }
        if (witnessversion == 0 && witnessprogram.size() == 32) {
            typeRet = TX_WITNESS_V0_SCRIPTHASH;
            vSolutionsRet.push_back(witnessprogram);
            return true;
        }
        if (witnessversion != 0) {
            typeRet = TX_WITNESS_UNKNOWN;
            vSolutionsRet.push_back(std::vector<unsigned char>{(unsigned char)witnessversion});