aboutsummaryrefslogtreecommitdiff
path: root/src/script/standard.h
blob: 4728b056dd14356ffba1fd46a779f5172626f51e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2017 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_SCRIPT_STANDARD_H
#define BITCOIN_SCRIPT_STANDARD_H

#include <script/interpreter.h>
#include <uint256.h>

#include <boost/variant.hpp>

#include <stdint.h>

static const bool DEFAULT_ACCEPT_DATACARRIER = true;

class CKeyID;
class CScript;

/** A reference to a CScript: the Hash160 of its serialization (see script.h) */
class CScriptID : public uint160
{
public:
    CScriptID() : uint160() {}
    explicit CScriptID(const CScript& in);
    CScriptID(const uint160& in) : uint160(in) {}
};

/**
 * Default setting for nMaxDatacarrierBytes. 80 bytes of data, +1 for OP_RETURN,
 * +2 for the pushdata opcodes.
 */
static const unsigned int MAX_OP_RETURN_RELAY = 83;

/**
 * A data carrying output is an unspendable output containing data. The script
 * type is designated as TX_NULL_DATA.
 */
extern bool fAcceptDatacarrier;

/** Maximum size of TX_NULL_DATA scripts that this node considers standard. */
extern unsigned nMaxDatacarrierBytes;

/**
 * Mandatory script verification flags that all new blocks must comply with for
 * them to be valid. (but old blocks may not comply with) Currently just P2SH,
 * but in the future other flags may be added, such as a soft-fork to enforce
 * strict DER encoding.
 *
 * Failing one of these tests may trigger a DoS ban - see CheckInputs() for
 * details.
 */
static const unsigned int MANDATORY_SCRIPT_VERIFY_FLAGS = SCRIPT_VERIFY_P2SH;

enum txnouttype
{
    TX_NONSTANDARD,
    // 'standard' transaction types:
    TX_PUBKEY,
    TX_PUBKEYHASH,
    TX_SCRIPTHASH,
    TX_MULTISIG,
    TX_NULL_DATA, //!< unspendable OP_RETURN script that carries data
    TX_WITNESS_V0_SCRIPTHASH,
    TX_WITNESS_V0_KEYHASH,
    TX_WITNESS_UNKNOWN, //!< Only for Witness versions not already defined above
};

class CNoDestination {
public:
    friend bool operator==(const CNoDestination &a, const CNoDestination &b) { return true; }
    friend bool operator<(const CNoDestination &a, const CNoDestination &b) { return true; }
};

struct WitnessV0ScriptHash : public uint256
{
    WitnessV0ScriptHash() : uint256() {}
    explicit WitnessV0ScriptHash(const uint256& hash) : uint256(hash) {}
    explicit WitnessV0ScriptHash(const CScript& script);
    using uint256::uint256;
};

struct WitnessV0KeyHash : public uint160
{
    WitnessV0KeyHash() : uint160() {}
    explicit WitnessV0KeyHash(const uint160& hash) : uint160(hash) {}
    using uint160::uint160;
};

//! CTxDestination subtype to encode any future Witness version
struct WitnessUnknown
{
    unsigned int version;
    unsigned int length;
    unsigned char program[40];

    friend bool operator==(const WitnessUnknown& w1, const WitnessUnknown& w2) {
        if (w1.version != w2.version) return false;
        if (w1.length != w2.length) return false;
        return std::equal(w1.program, w1.program + w1.length, w2.program);
    }

    friend bool operator<(const WitnessUnknown& w1, const WitnessUnknown& w2) {
        if (w1.version < w2.version) return true;
        if (w1.version > w2.version) return false;
        if (w1.length < w2.length) return true;
        if (w1.length > w2.length) return false;
        return std::lexicographical_compare(w1.program, w1.program + w1.length, w2.program, w2.program + w2.length);
    }
};

/**
 * A txout script template with a specific destination. It is either:
 *  * CNoDestination: no destination set
 *  * CKeyID: TX_PUBKEYHASH destination (P2PKH)
 *  * CScriptID: TX_SCRIPTHASH destination (P2SH)
 *  * WitnessV0ScriptHash: TX_WITNESS_V0_SCRIPTHASH destination (P2WSH)
 *  * WitnessV0KeyHash: TX_WITNESS_V0_KEYHASH destination (P2WPKH)
 *  * WitnessUnknown: TX_WITNESS_UNKNOWN destination (P2W???)
 *  A CTxDestination is the internal data type encoded in a bitcoin address
 */
typedef boost::variant<CNoDestination, CKeyID, CScriptID, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessUnknown> CTxDestination;

/** Check whether a CTxDestination is a CNoDestination. */
bool IsValidDestination(const CTxDestination& dest);

/** Get the name of a txnouttype as a C string, or nullptr if unknown. */
const char* GetTxnOutputType(txnouttype t);

/**
 * Parse a scriptPubKey and identify script type for standard scripts. If
 * successful, returns script type and parsed pubkeys or hashes, depending on
 * the type. For example, for a P2SH script, vSolutionsRet will contain the
 * script hash, for P2PKH it will contain the key hash, etc.
 *
 * @param[in]   scriptPubKey   Script to parse
 * @param[out]  vSolutionsRet  Vector of parsed pubkeys and hashes
 * @return                     The script type. TX_NONSTANDARD represents a failed solve.
 */
txnouttype Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned char>>& vSolutionsRet);

/**
 * Parse a standard scriptPubKey for the destination address. Assigns result to
 * the addressRet parameter and returns true if successful. For multisig
 * scripts, instead use ExtractDestinations. Currently only works for P2PK,
 * P2PKH, P2SH, P2WPKH, and P2WSH scripts.
 */
bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet);

/**
 * Parse a standard scriptPubKey with one or more destination addresses. For
 * multisig scripts, this populates the addressRet vector with the pubkey IDs
 * and nRequiredRet with the n required to spend. For other destinations,
 * addressRet is populated with a single value and nRequiredRet is set to 1.
 * Returns true if successful. Currently does not extract address from
 * pay-to-witness scripts.
 *
 * Note: this function confuses destinations (a subset of CScripts that are
 * encodable as an address) with key identifiers (of keys involved in a
 * CScript), and its use should be phased out.
 */
bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);

/**
 * Generate a Bitcoin scriptPubKey for the given CTxDestination. Returns a P2PKH
 * script for a CKeyID destination, a P2SH script for a CScriptID, and an empty
 * script for CNoDestination.
 */
CScript GetScriptForDestination(const CTxDestination& dest);

/** Generate a P2PK script for the given pubkey. */
CScript GetScriptForRawPubKey(const CPubKey& pubkey);

/** Generate a multisig script. */
CScript GetScriptForMultisig(int nRequired, const std::vector<CPubKey>& keys);

/**
 * Generate a pay-to-witness script for the given redeem script. If the redeem
 * script is P2PK or P2PKH, this returns a P2WPKH script, otherwise it returns a
 * P2WSH script.
 *
 * TODO: replace calls to GetScriptForWitness with GetScriptForDestination using
 * the various witness-specific CTxDestination subtypes.
 */
CScript GetScriptForWitness(const CScript& redeemscript);

#endif // BITCOIN_SCRIPT_STANDARD_H