1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2015 The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 
6 #include "script.h"
7 
8 #include "tinyformat.h"
9 #include "utilstrencodings.h"
10 
11 using namespace std;
12 
GetOpName(opcodetype opcode)13 const char* GetOpName(opcodetype opcode)
14 {
15     switch (opcode)
16     {
17     // push value
18     case OP_0                      : return "0";
19     case OP_PUSHDATA1              : return "OP_PUSHDATA1";
20     case OP_PUSHDATA2              : return "OP_PUSHDATA2";
21     case OP_PUSHDATA4              : return "OP_PUSHDATA4";
22     case OP_1NEGATE                : return "-1";
23     case OP_RESERVED               : return "OP_RESERVED";
24     case OP_1                      : return "1";
25     case OP_2                      : return "2";
26     case OP_3                      : return "3";
27     case OP_4                      : return "4";
28     case OP_5                      : return "5";
29     case OP_6                      : return "6";
30     case OP_7                      : return "7";
31     case OP_8                      : return "8";
32     case OP_9                      : return "9";
33     case OP_10                     : return "10";
34     case OP_11                     : return "11";
35     case OP_12                     : return "12";
36     case OP_13                     : return "13";
37     case OP_14                     : return "14";
38     case OP_15                     : return "15";
39     case OP_16                     : return "16";
40 
41     // control
42     case OP_NOP                    : return "OP_NOP";
43     case OP_VER                    : return "OP_VER";
44     case OP_IF                     : return "OP_IF";
45     case OP_NOTIF                  : return "OP_NOTIF";
46     case OP_VERIF                  : return "OP_VERIF";
47     case OP_VERNOTIF               : return "OP_VERNOTIF";
48     case OP_ELSE                   : return "OP_ELSE";
49     case OP_ENDIF                  : return "OP_ENDIF";
50     case OP_VERIFY                 : return "OP_VERIFY";
51     case OP_RETURN                 : return "OP_RETURN";
52 
53     // stack ops
54     case OP_TOALTSTACK             : return "OP_TOALTSTACK";
55     case OP_FROMALTSTACK           : return "OP_FROMALTSTACK";
56     case OP_2DROP                  : return "OP_2DROP";
57     case OP_2DUP                   : return "OP_2DUP";
58     case OP_3DUP                   : return "OP_3DUP";
59     case OP_2OVER                  : return "OP_2OVER";
60     case OP_2ROT                   : return "OP_2ROT";
61     case OP_2SWAP                  : return "OP_2SWAP";
62     case OP_IFDUP                  : return "OP_IFDUP";
63     case OP_DEPTH                  : return "OP_DEPTH";
64     case OP_DROP                   : return "OP_DROP";
65     case OP_DUP                    : return "OP_DUP";
66     case OP_NIP                    : return "OP_NIP";
67     case OP_OVER                   : return "OP_OVER";
68     case OP_PICK                   : return "OP_PICK";
69     case OP_ROLL                   : return "OP_ROLL";
70     case OP_ROT                    : return "OP_ROT";
71     case OP_SWAP                   : return "OP_SWAP";
72     case OP_TUCK                   : return "OP_TUCK";
73 
74     // splice ops
75     case OP_CAT                    : return "OP_CAT";
76     case OP_SUBSTR                 : return "OP_SUBSTR";
77     case OP_LEFT                   : return "OP_LEFT";
78     case OP_RIGHT                  : return "OP_RIGHT";
79     case OP_SIZE                   : return "OP_SIZE";
80 
81     // bit logic
82     case OP_INVERT                 : return "OP_INVERT";
83     case OP_AND                    : return "OP_AND";
84     case OP_OR                     : return "OP_OR";
85     case OP_XOR                    : return "OP_XOR";
86     case OP_EQUAL                  : return "OP_EQUAL";
87     case OP_EQUALVERIFY            : return "OP_EQUALVERIFY";
88     case OP_RESERVED1              : return "OP_RESERVED1";
89     case OP_RESERVED2              : return "OP_RESERVED2";
90 
91     // numeric
92     case OP_1ADD                   : return "OP_1ADD";
93     case OP_1SUB                   : return "OP_1SUB";
94     case OP_2MUL                   : return "OP_2MUL";
95     case OP_2DIV                   : return "OP_2DIV";
96     case OP_NEGATE                 : return "OP_NEGATE";
97     case OP_ABS                    : return "OP_ABS";
98     case OP_NOT                    : return "OP_NOT";
99     case OP_0NOTEQUAL              : return "OP_0NOTEQUAL";
100     case OP_ADD                    : return "OP_ADD";
101     case OP_SUB                    : return "OP_SUB";
102     case OP_MUL                    : return "OP_MUL";
103     case OP_DIV                    : return "OP_DIV";
104     case OP_MOD                    : return "OP_MOD";
105     case OP_LSHIFT                 : return "OP_LSHIFT";
106     case OP_RSHIFT                 : return "OP_RSHIFT";
107     case OP_BOOLAND                : return "OP_BOOLAND";
108     case OP_BOOLOR                 : return "OP_BOOLOR";
109     case OP_NUMEQUAL               : return "OP_NUMEQUAL";
110     case OP_NUMEQUALVERIFY         : return "OP_NUMEQUALVERIFY";
111     case OP_NUMNOTEQUAL            : return "OP_NUMNOTEQUAL";
112     case OP_LESSTHAN               : return "OP_LESSTHAN";
113     case OP_GREATERTHAN            : return "OP_GREATERTHAN";
114     case OP_LESSTHANOREQUAL        : return "OP_LESSTHANOREQUAL";
115     case OP_GREATERTHANOREQUAL     : return "OP_GREATERTHANOREQUAL";
116     case OP_MIN                    : return "OP_MIN";
117     case OP_MAX                    : return "OP_MAX";
118     case OP_WITHIN                 : return "OP_WITHIN";
119 
120     // crypto
121     case OP_RIPEMD160              : return "OP_RIPEMD160";
122     case OP_SHA1                   : return "OP_SHA1";
123     case OP_SHA256                 : return "OP_SHA256";
124     case OP_HASH160                : return "OP_HASH160";
125     case OP_HASH256                : return "OP_HASH256";
126     case OP_CODESEPARATOR          : return "OP_CODESEPARATOR";
127     case OP_CHECKSIG               : return "OP_CHECKSIG";
128     case OP_CHECKSIGVERIFY         : return "OP_CHECKSIGVERIFY";
129     case OP_CHECKMULTISIG          : return "OP_CHECKMULTISIG";
130     case OP_CHECKMULTISIGVERIFY    : return "OP_CHECKMULTISIGVERIFY";
131 
132     // expanson
133     case OP_NOP1                   : return "OP_NOP1";
134     case OP_CHECKLOCKTIMEVERIFY    : return "OP_CHECKLOCKTIMEVERIFY";
135     case OP_CHECKSEQUENCEVERIFY    : return "OP_CHECKSEQUENCEVERIFY";
136     case OP_NOP4                   : return "OP_NOP4";
137     case OP_NOP5                   : return "OP_NOP5";
138     case OP_NOP6                   : return "OP_NOP6";
139     case OP_NOP7                   : return "OP_NOP7";
140     case OP_NOP8                   : return "OP_NOP8";
141     case OP_NOP9                   : return "OP_NOP9";
142     case OP_NOP10                  : return "OP_NOP10";
143 
144     case OP_INVALIDOPCODE          : return "OP_INVALIDOPCODE";
145 
146     // Note:
147     //  The template matching params OP_SMALLINTEGER/etc are defined in opcodetype enum
148     //  as kind of implementation hack, they are *NOT* real opcodes.  If found in real
149     //  Script, just let the default: case deal with them.
150 
151     default:
152         return "OP_UNKNOWN";
153     }
154 }
155 
GetSigOpCount(bool fAccurate) const156 unsigned int CScript::GetSigOpCount(bool fAccurate) const
157 {
158     unsigned int n = 0;
159     const_iterator pc = begin();
160     opcodetype lastOpcode = OP_INVALIDOPCODE;
161     while (pc < end())
162     {
163         opcodetype opcode;
164         if (!GetOp(pc, opcode))
165             break;
166         if (opcode == OP_CHECKSIG || opcode == OP_CHECKSIGVERIFY)
167             n++;
168         else if (opcode == OP_CHECKMULTISIG || opcode == OP_CHECKMULTISIGVERIFY)
169         {
170             if (fAccurate && lastOpcode >= OP_1 && lastOpcode <= OP_16)
171                 n += DecodeOP_N(lastOpcode);
172             else
173                 n += MAX_PUBKEYS_PER_MULTISIG;
174         }
175         lastOpcode = opcode;
176     }
177     return n;
178 }
179 
GetSigOpCount(const CScript & scriptSig) const180 unsigned int CScript::GetSigOpCount(const CScript& scriptSig) const
181 {
182     if (!IsPayToScriptHash())
183         return GetSigOpCount(true);
184 
185     // This is a pay-to-script-hash scriptPubKey;
186     // get the last item that the scriptSig
187     // pushes onto the stack:
188     const_iterator pc = scriptSig.begin();
189     vector<unsigned char> data;
190     while (pc < scriptSig.end())
191     {
192         opcodetype opcode;
193         if (!scriptSig.GetOp(pc, opcode, data))
194             return 0;
195         if (opcode > OP_16)
196             return 0;
197     }
198 
199     /// ... and return its opcount:
200     CScript subscript(data.begin(), data.end());
201     return subscript.GetSigOpCount(true);
202 }
203 
IsPayToScriptHash() const204 bool CScript::IsPayToScriptHash() const
205 {
206     // Extra-fast test for pay-to-script-hash CScripts:
207     return (this->size() == 23 &&
208             (*this)[0] == OP_HASH160 &&
209             (*this)[1] == 0x14 &&
210             (*this)[22] == OP_EQUAL);
211 }
212 
IsPayToWitnessScriptHash() const213 bool CScript::IsPayToWitnessScriptHash() const
214 {
215     // Extra-fast test for pay-to-witness-script-hash CScripts:
216     return (this->size() == 34 &&
217             (*this)[0] == OP_0 &&
218             (*this)[1] == 0x20);
219 }
220 
221 // A witness program is any valid CScript that consists of a 1-byte push opcode
222 // followed by a data push between 2 and 40 bytes.
IsWitnessProgram(int & version,std::vector<unsigned char> & program) const223 bool CScript::IsWitnessProgram(int& version, std::vector<unsigned char>& program) const
224 {
225     if (this->size() < 4 || this->size() > 42) {
226         return false;
227     }
228     if ((*this)[0] != OP_0 && ((*this)[0] < OP_1 || (*this)[0] > OP_16)) {
229         return false;
230     }
231     if ((size_t)((*this)[1] + 2) == this->size()) {
232         version = DecodeOP_N((opcodetype)(*this)[0]);
233         program = std::vector<unsigned char>(this->begin() + 2, this->end());
234         return true;
235     }
236     return false;
237 }
238 
IsPushOnly(const_iterator pc) const239 bool CScript::IsPushOnly(const_iterator pc) const
240 {
241     while (pc < end())
242     {
243         opcodetype opcode;
244         if (!GetOp(pc, opcode))
245             return false;
246         // Note that IsPushOnly() *does* consider OP_RESERVED to be a
247         // push-type opcode, however execution of OP_RESERVED fails, so
248         // it's not relevant to P2SH/BIP62 as the scriptSig would fail prior to
249         // the P2SH special validation code being executed.
250         if (opcode > OP_16)
251             return false;
252     }
253     return true;
254 }
255 
IsPushOnly() const256 bool CScript::IsPushOnly() const
257 {
258     return this->IsPushOnly(begin());
259 }
260 
ToString() const261 std::string CScriptWitness::ToString() const
262 {
263     std::string ret = "CScriptWitness(";
264     for (unsigned int i = 0; i < stack.size(); i++) {
265         if (i) {
266             ret += ", ";
267         }
268         ret += HexStr(stack[i]);
269     }
270     return ret + ")";
271 }
272