// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers
// Copyright (c) 2017-2018 The Bitcoin developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_SCRIPT_SCRIPTFLAGS_H
#define BITCOIN_SCRIPT_SCRIPTFLAGS_H

/** Script verification flags */
enum
{
    SCRIPT_VERIFY_NONE      = 0,

    // Evaluate P2SH subscripts (softfork safe, BIP16).
    SCRIPT_VERIFY_P2SH      = (1U << 0),

    // Passing a non-strict-DER signature or one with undefined hashtype to a checksig operation causes script failure.
    // Evaluating a pubkey that is not (0x04 + 64 bytes) or (0x02 or 0x03 + 32 bytes) by checksig causes script failure.
    // (softfork safe, but not used or intended as a consensus rule).
    SCRIPT_VERIFY_STRICTENC = (1U << 1),

    // Bit 2 (BIP62 rule 1, strict-DER signatures) is unused in Zclassic.

    // Passing a non-strict-DER signature or one with S > order/2 to a checksig operation causes script failure
    // (softfork safe, BIP62 rule 5).
    SCRIPT_VERIFY_LOW_S     = (1U << 3),

    // verify dummy stack item consumed by CHECKMULTISIG is of zero-length (softfork safe, BIP62 rule 7).
    SCRIPT_VERIFY_NULLDUMMY = (1U << 4),

    // Using a non-push operator in the scriptSig causes script failure (softfork safe, BIP62 rule 2).
    SCRIPT_VERIFY_SIGPUSHONLY = (1U << 5),

    // Require minimal encodings for all push operations (OP_0... OP_16, OP_1NEGATE where possible, direct
    // pushes up to 75 bytes, OP_PUSHDATA up to 255 bytes, OP_PUSHDATA2 for anything larger). Evaluating
    // any other push causes the script to fail (BIP62 rule 3).
    // In addition, whenever a stack element is interpreted as a number, it must be of minimal length (BIP62 rule 4).
    // (softfork safe)
    SCRIPT_VERIFY_MINIMALDATA = (1U << 6),

    // Discourage use of NOPs reserved for upgrades (NOP1-10)
    //
    // Provided so that nodes can avoid accepting or mining transactions
    // containing executed NOP's whose meaning may change after a soft-fork,
    // thus rendering the script invalid; with this flag set executing
    // discouraged NOPs fails the script. This verification flag will never be
    // a mandatory flag applied to scripts in a block. NOPs that are not
    // executed, e.g.  within an unexecuted IF ENDIF block, are *not* rejected.
    SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS  = (1U << 7),

    // Require that only a single stack element remains after evaluation. This changes the success criterion from
    // "At least one stack element must remain, and when interpreted as a boolean, it must be true" to
    // "Exactly one stack element must remain, and when interpreted as a boolean, it must be true".
    // (softfork safe, BIP62 rule 6)
    // Note: CLEANSTACK should never be used without P2SH.
    SCRIPT_VERIFY_CLEANSTACK = (1U << 8),

    // Verify CHECKLOCKTIMEVERIFY
    //
    // See BIP65 for details.
    SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY = (1U << 9),

    // Signature(s) must be empty vector if an CHECK(MULTI)SIG operation failed
    //
    SCRIPT_VERIFY_NULLFAIL = (1U << 10),

    // Is OP_CHECKDATASIG and variant are enabled.
    //
    SCRIPT_VERIFY_CHECKDATASIG_SIGOPS = (1U << 11),
};

#endif // BITCOIN_SCRIPT_SCRIPTFLAGS_H
