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-rw-r--r--src/script/interpreter.cpp1229
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diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
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+++ b/src/script/interpreter.cpp
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+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "interpreter.h"
+
+#include "primitives/transaction.h"
+#include "crypto/ripemd160.h"
+#include "crypto/sha1.h"
+#include "crypto/sha256.h"
+#include "eccryptoverify.h"
+#include "pubkey.h"
+#include "script/script.h"
+#include "uint256.h"
+
+using namespace std;
+
+typedef vector<unsigned char> valtype;
+
+namespace {
+
+inline bool set_success(ScriptError* ret)
+{
+ if (ret)
+ *ret = SCRIPT_ERR_OK;
+ return true;
+}
+
+inline bool set_error(ScriptError* ret, const ScriptError serror)
+{
+ if (ret)
+ *ret = serror;
+ return false;
+}
+
+} // anon namespace
+
+bool CastToBool(const valtype& vch)
+{
+ for (unsigned int i = 0; i < vch.size(); i++)
+ {
+ if (vch[i] != 0)
+ {
+ // Can be negative zero
+ if (i == vch.size()-1 && vch[i] == 0x80)
+ return false;
+ return true;
+ }
+ }
+ return false;
+}
+
+/**
+ * Script is a stack machine (like Forth) that evaluates a predicate
+ * returning a bool indicating valid or not. There are no loops.
+ */
+#define stacktop(i) (stack.at(stack.size()+(i)))
+#define altstacktop(i) (altstack.at(altstack.size()+(i)))
+static inline void popstack(vector<valtype>& stack)
+{
+ if (stack.empty())
+ throw runtime_error("popstack(): stack empty");
+ stack.pop_back();
+}
+
+bool static IsCompressedOrUncompressedPubKey(const valtype &vchPubKey) {
+ if (vchPubKey.size() < 33) {
+ // Non-canonical public key: too short
+ return false;
+ }
+ if (vchPubKey[0] == 0x04) {
+ if (vchPubKey.size() != 65) {
+ // Non-canonical public key: invalid length for uncompressed key
+ return false;
+ }
+ } else if (vchPubKey[0] == 0x02 || vchPubKey[0] == 0x03) {
+ if (vchPubKey.size() != 33) {
+ // Non-canonical public key: invalid length for compressed key
+ return false;
+ }
+ } else {
+ // Non-canonical public key: neither compressed nor uncompressed
+ return false;
+ }
+ return true;
+}
+
+/**
+ * A canonical signature exists of: <30> <total len> <02> <len R> <R> <02> <len S> <S> <hashtype>
+ * Where R and S are not negative (their first byte has its highest bit not set), and not
+ * excessively padded (do not start with a 0 byte, unless an otherwise negative number follows,
+ * in which case a single 0 byte is necessary and even required).
+ *
+ * See https://bitcointalk.org/index.php?topic=8392.msg127623#msg127623
+ *
+ * This function is consensus-critical since BIP66.
+ */
+bool static IsValidSignatureEncoding(const std::vector<unsigned char> &sig) {
+ // Format: 0x30 [total-length] 0x02 [R-length] [R] 0x02 [S-length] [S] [sighash]
+ // * total-length: 1-byte length descriptor of everything that follows,
+ // excluding the sighash byte.
+ // * R-length: 1-byte length descriptor of the R value that follows.
+ // * R: arbitrary-length big-endian encoded R value. It must use the shortest
+ // possible encoding for a positive integers (which means no null bytes at
+ // the start, except a single one when the next byte has its highest bit set).
+ // * S-length: 1-byte length descriptor of the S value that follows.
+ // * S: arbitrary-length big-endian encoded S value. The same rules apply.
+ // * sighash: 1-byte value indicating what data is hashed (not part of the DER
+ // signature)
+
+ // Minimum and maximum size constraints.
+ if (sig.size() < 9) return false;
+ if (sig.size() > 73) return false;
+
+ // A signature is of type 0x30 (compound).
+ if (sig[0] != 0x30) return false;
+
+ // Make sure the length covers the entire signature.
+ if (sig[1] != sig.size() - 3) return false;
+
+ // Extract the length of the R element.
+ unsigned int lenR = sig[3];
+
+ // Make sure the length of the S element is still inside the signature.
+ if (5 + lenR >= sig.size()) return false;
+
+ // Extract the length of the S element.
+ unsigned int lenS = sig[5 + lenR];
+
+ // Verify that the length of the signature matches the sum of the length
+ // of the elements.
+ if ((size_t)(lenR + lenS + 7) != sig.size()) return false;
+
+ // Check whether the R element is an integer.
+ if (sig[2] != 0x02) return false;
+
+ // Zero-length integers are not allowed for R.
+ if (lenR == 0) return false;
+
+ // Negative numbers are not allowed for R.
+ if (sig[4] & 0x80) return false;
+
+ // Null bytes at the start of R are not allowed, unless R would
+ // otherwise be interpreted as a negative number.
+ if (lenR > 1 && (sig[4] == 0x00) && !(sig[5] & 0x80)) return false;
+
+ // Check whether the S element is an integer.
+ if (sig[lenR + 4] != 0x02) return false;
+
+ // Zero-length integers are not allowed for S.
+ if (lenS == 0) return false;
+
+ // Negative numbers are not allowed for S.
+ if (sig[lenR + 6] & 0x80) return false;
+
+ // Null bytes at the start of S are not allowed, unless S would otherwise be
+ // interpreted as a negative number.
+ if (lenS > 1 && (sig[lenR + 6] == 0x00) && !(sig[lenR + 7] & 0x80)) return false;
+
+ return true;
+}
+
+bool static IsLowDERSignature(const valtype &vchSig, ScriptError* serror) {
+ if (!IsValidSignatureEncoding(vchSig)) {
+ return set_error(serror, SCRIPT_ERR_SIG_DER);
+ }
+ unsigned int nLenR = vchSig[3];
+ unsigned int nLenS = vchSig[5+nLenR];
+ const unsigned char *S = &vchSig[6+nLenR];
+ // If the S value is above the order of the curve divided by two, its
+ // complement modulo the order could have been used instead, which is
+ // one byte shorter when encoded correctly.
+ if (!eccrypto::CheckSignatureElement(S, nLenS, true))
+ return set_error(serror, SCRIPT_ERR_SIG_HIGH_S);
+
+ return true;
+}
+
+bool static IsDefinedHashtypeSignature(const valtype &vchSig) {
+ if (vchSig.size() == 0) {
+ return false;
+ }
+ unsigned char nHashType = vchSig[vchSig.size() - 1] & (~(SIGHASH_ANYONECANPAY));
+ if (nHashType < SIGHASH_ALL || nHashType > SIGHASH_SINGLE)
+ return false;
+
+ return true;
+}
+
+bool CheckSignatureEncoding(const vector<unsigned char> &vchSig, unsigned int flags, ScriptError* serror) {
+ // Empty signature. Not strictly DER encoded, but allowed to provide a
+ // compact way to provide an invalid signature for use with CHECK(MULTI)SIG
+ if (vchSig.size() == 0) {
+ return true;
+ }
+ if ((flags & (SCRIPT_VERIFY_DERSIG | SCRIPT_VERIFY_LOW_S | SCRIPT_VERIFY_STRICTENC)) != 0 && !IsValidSignatureEncoding(vchSig)) {
+ return set_error(serror, SCRIPT_ERR_SIG_DER);
+ } else if ((flags & SCRIPT_VERIFY_LOW_S) != 0 && !IsLowDERSignature(vchSig, serror)) {
+ // serror is set
+ return false;
+ } else if ((flags & SCRIPT_VERIFY_STRICTENC) != 0 && !IsDefinedHashtypeSignature(vchSig)) {
+ return set_error(serror, SCRIPT_ERR_SIG_HASHTYPE);
+ }
+ return true;
+}
+
+bool static CheckPubKeyEncoding(const valtype &vchSig, unsigned int flags, ScriptError* serror) {
+ if ((flags & SCRIPT_VERIFY_STRICTENC) != 0 && !IsCompressedOrUncompressedPubKey(vchSig)) {
+ return set_error(serror, SCRIPT_ERR_PUBKEYTYPE);
+ }
+ return true;
+}
+
+bool static CheckMinimalPush(const valtype& data, opcodetype opcode) {
+ if (data.size() == 0) {
+ // Could have used OP_0.
+ return opcode == OP_0;
+ } else if (data.size() == 1 && data[0] >= 1 && data[0] <= 16) {
+ // Could have used OP_1 .. OP_16.
+ return opcode == OP_1 + (data[0] - 1);
+ } else if (data.size() == 1 && data[0] == 0x81) {
+ // Could have used OP_1NEGATE.
+ return opcode == OP_1NEGATE;
+ } else if (data.size() <= 75) {
+ // Could have used a direct push (opcode indicating number of bytes pushed + those bytes).
+ return opcode == data.size();
+ } else if (data.size() <= 255) {
+ // Could have used OP_PUSHDATA.
+ return opcode == OP_PUSHDATA1;
+ } else if (data.size() <= 65535) {
+ // Could have used OP_PUSHDATA2.
+ return opcode == OP_PUSHDATA2;
+ }
+ return true;
+}
+
+bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror)
+{
+ static const CScriptNum bnZero(0);
+ static const CScriptNum bnOne(1);
+ static const CScriptNum bnFalse(0);
+ static const CScriptNum bnTrue(1);
+ static const valtype vchFalse(0);
+ static const valtype vchZero(0);
+ static const valtype vchTrue(1, 1);
+
+ CScript::const_iterator pc = script.begin();
+ CScript::const_iterator pend = script.end();
+ CScript::const_iterator pbegincodehash = script.begin();
+ opcodetype opcode;
+ valtype vchPushValue;
+ vector<bool> vfExec;
+ vector<valtype> altstack;
+ set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);
+ if (script.size() > 10000)
+ return set_error(serror, SCRIPT_ERR_SCRIPT_SIZE);
+ int nOpCount = 0;
+ bool fRequireMinimal = (flags & SCRIPT_VERIFY_MINIMALDATA) != 0;
+
+ try
+ {
+ while (pc < pend)
+ {
+ bool fExec = !count(vfExec.begin(), vfExec.end(), false);
+
+ //
+ // Read instruction
+ //
+ if (!script.GetOp(pc, opcode, vchPushValue))
+ return set_error(serror, SCRIPT_ERR_BAD_OPCODE);
+ if (vchPushValue.size() > MAX_SCRIPT_ELEMENT_SIZE)
+ return set_error(serror, SCRIPT_ERR_PUSH_SIZE);
+
+ // Note how OP_RESERVED does not count towards the opcode limit.
+ if (opcode > OP_16 && ++nOpCount > MAX_OPS_PER_SCRIPT)
+ return set_error(serror, SCRIPT_ERR_OP_COUNT);
+
+ if (opcode == OP_CAT ||
+ opcode == OP_SUBSTR ||
+ opcode == OP_LEFT ||
+ opcode == OP_RIGHT ||
+ opcode == OP_INVERT ||
+ opcode == OP_AND ||
+ opcode == OP_OR ||
+ opcode == OP_XOR ||
+ opcode == OP_2MUL ||
+ opcode == OP_2DIV ||
+ opcode == OP_MUL ||
+ opcode == OP_DIV ||
+ opcode == OP_MOD ||
+ opcode == OP_LSHIFT ||
+ opcode == OP_RSHIFT)
+ return set_error(serror, SCRIPT_ERR_DISABLED_OPCODE); // Disabled opcodes.
+
+ if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4) {
+ if (fRequireMinimal && !CheckMinimalPush(vchPushValue, opcode)) {
+ return set_error(serror, SCRIPT_ERR_MINIMALDATA);
+ }
+ stack.push_back(vchPushValue);
+ } else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))
+ switch (opcode)
+ {
+ //
+ // Push value
+ //
+ case OP_1NEGATE:
+ case OP_1:
+ case OP_2:
+ case OP_3:
+ case OP_4:
+ case OP_5:
+ case OP_6:
+ case OP_7:
+ case OP_8:
+ case OP_9:
+ case OP_10:
+ case OP_11:
+ case OP_12:
+ case OP_13:
+ case OP_14:
+ case OP_15:
+ case OP_16:
+ {
+ // ( -- value)
+ CScriptNum bn((int)opcode - (int)(OP_1 - 1));
+ stack.push_back(bn.getvch());
+ // The result of these opcodes should always be the minimal way to push the data
+ // they push, so no need for a CheckMinimalPush here.
+ }
+ break;
+
+
+ //
+ // Control
+ //
+ case OP_NOP:
+ break;
+
+ case OP_CHECKLOCKTIMEVERIFY:
+ {
+ if (!(flags & SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY)) {
+ // not enabled; treat as a NOP2
+ if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) {
+ return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS);
+ }
+ break;
+ }
+
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+
+ // Note that elsewhere numeric opcodes are limited to
+ // operands in the range -2**31+1 to 2**31-1, however it is
+ // legal for opcodes to produce results exceeding that
+ // range. This limitation is implemented by CScriptNum's
+ // default 4-byte limit.
+ //
+ // If we kept to that limit we'd have a year 2038 problem,
+ // even though the nLockTime field in transactions
+ // themselves is uint32 which only becomes meaningless
+ // after the year 2106.
+ //
+ // Thus as a special case we tell CScriptNum to accept up
+ // to 5-byte bignums, which are good until 2**39-1, well
+ // beyond the 2**32-1 limit of the nLockTime field itself.
+ const CScriptNum nLockTime(stacktop(-1), fRequireMinimal, 5);
+
+ // In the rare event that the argument may be < 0 due to
+ // some arithmetic being done first, you can always use
+ // 0 MAX CHECKLOCKTIMEVERIFY.
+ if (nLockTime < 0)
+ return set_error(serror, SCRIPT_ERR_NEGATIVE_LOCKTIME);
+
+ // Actually compare the specified lock time with the transaction.
+ if (!checker.CheckLockTime(nLockTime))
+ return set_error(serror, SCRIPT_ERR_UNSATISFIED_LOCKTIME);
+
+ break;
+ }
+
+ case OP_NOP1: case OP_NOP3: case OP_NOP4: case OP_NOP5:
+ case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10:
+ {
+ if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS)
+ return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS);
+ }
+ break;
+
+ case OP_IF:
+ case OP_NOTIF:
+ {
+ // <expression> if [statements] [else [statements]] endif
+ bool fValue = false;
+ if (fExec)
+ {
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL);
+ valtype& vch = stacktop(-1);
+ fValue = CastToBool(vch);
+ if (opcode == OP_NOTIF)
+ fValue = !fValue;
+ popstack(stack);
+ }
+ vfExec.push_back(fValue);
+ }
+ break;
+
+ case OP_ELSE:
+ {
+ if (vfExec.empty())
+ return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL);
+ vfExec.back() = !vfExec.back();
+ }
+ break;
+
+ case OP_ENDIF:
+ {
+ if (vfExec.empty())
+ return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL);
+ vfExec.pop_back();
+ }
+ break;
+
+ case OP_VERIFY:
+ {
+ // (true -- ) or
+ // (false -- false) and return
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ bool fValue = CastToBool(stacktop(-1));
+ if (fValue)
+ popstack(stack);
+ else
+ return set_error(serror, SCRIPT_ERR_VERIFY);
+ }
+ break;
+
+ case OP_RETURN:
+ {
+ return set_error(serror, SCRIPT_ERR_OP_RETURN);
+ }
+ break;
+
+
+ //
+ // Stack ops
+ //
+ case OP_TOALTSTACK:
+ {
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ altstack.push_back(stacktop(-1));
+ popstack(stack);
+ }
+ break;
+
+ case OP_FROMALTSTACK:
+ {
+ if (altstack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_ALTSTACK_OPERATION);
+ stack.push_back(altstacktop(-1));
+ popstack(altstack);
+ }
+ break;
+
+ case OP_2DROP:
+ {
+ // (x1 x2 -- )
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ popstack(stack);
+ popstack(stack);
+ }
+ break;
+
+ case OP_2DUP:
+ {
+ // (x1 x2 -- x1 x2 x1 x2)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch1 = stacktop(-2);
+ valtype vch2 = stacktop(-1);
+ stack.push_back(vch1);
+ stack.push_back(vch2);
+ }
+ break;
+
+ case OP_3DUP:
+ {
+ // (x1 x2 x3 -- x1 x2 x3 x1 x2 x3)
+ if (stack.size() < 3)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch1 = stacktop(-3);
+ valtype vch2 = stacktop(-2);
+ valtype vch3 = stacktop(-1);
+ stack.push_back(vch1);
+ stack.push_back(vch2);
+ stack.push_back(vch3);
+ }
+ break;
+
+ case OP_2OVER:
+ {
+ // (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2)
+ if (stack.size() < 4)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch1 = stacktop(-4);
+ valtype vch2 = stacktop(-3);
+ stack.push_back(vch1);
+ stack.push_back(vch2);
+ }
+ break;
+
+ case OP_2ROT:
+ {
+ // (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2)
+ if (stack.size() < 6)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch1 = stacktop(-6);
+ valtype vch2 = stacktop(-5);
+ stack.erase(stack.end()-6, stack.end()-4);
+ stack.push_back(vch1);
+ stack.push_back(vch2);
+ }
+ break;
+
+ case OP_2SWAP:
+ {
+ // (x1 x2 x3 x4 -- x3 x4 x1 x2)
+ if (stack.size() < 4)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ swap(stacktop(-4), stacktop(-2));
+ swap(stacktop(-3), stacktop(-1));
+ }
+ break;
+
+ case OP_IFDUP:
+ {
+ // (x - 0 | x x)
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch = stacktop(-1);
+ if (CastToBool(vch))
+ stack.push_back(vch);
+ }
+ break;
+
+ case OP_DEPTH:
+ {
+ // -- stacksize
+ CScriptNum bn(stack.size());
+ stack.push_back(bn.getvch());
+ }
+ break;
+
+ case OP_DROP:
+ {
+ // (x -- )
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ popstack(stack);
+ }
+ break;
+
+ case OP_DUP:
+ {
+ // (x -- x x)
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch = stacktop(-1);
+ stack.push_back(vch);
+ }
+ break;
+
+ case OP_NIP:
+ {
+ // (x1 x2 -- x2)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ stack.erase(stack.end() - 2);
+ }
+ break;
+
+ case OP_OVER:
+ {
+ // (x1 x2 -- x1 x2 x1)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch = stacktop(-2);
+ stack.push_back(vch);
+ }
+ break;
+
+ case OP_PICK:
+ case OP_ROLL:
+ {
+ // (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn)
+ // (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ int n = CScriptNum(stacktop(-1), fRequireMinimal).getint();
+ popstack(stack);
+ if (n < 0 || n >= (int)stack.size())
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch = stacktop(-n-1);
+ if (opcode == OP_ROLL)
+ stack.erase(stack.end()-n-1);
+ stack.push_back(vch);
+ }
+ break;
+
+ case OP_ROT:
+ {
+ // (x1 x2 x3 -- x2 x3 x1)
+ // x2 x1 x3 after first swap
+ // x2 x3 x1 after second swap
+ if (stack.size() < 3)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ swap(stacktop(-3), stacktop(-2));
+ swap(stacktop(-2), stacktop(-1));
+ }
+ break;
+
+ case OP_SWAP:
+ {
+ // (x1 x2 -- x2 x1)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ swap(stacktop(-2), stacktop(-1));
+ }
+ break;
+
+ case OP_TUCK:
+ {
+ // (x1 x2 -- x2 x1 x2)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype vch = stacktop(-1);
+ stack.insert(stack.end()-2, vch);
+ }
+ break;
+
+
+ case OP_SIZE:
+ {
+ // (in -- in size)
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ CScriptNum bn(stacktop(-1).size());
+ stack.push_back(bn.getvch());
+ }
+ break;
+
+
+ //
+ // Bitwise logic
+ //
+ case OP_EQUAL:
+ case OP_EQUALVERIFY:
+ //case OP_NOTEQUAL: // use OP_NUMNOTEQUAL
+ {
+ // (x1 x2 - bool)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype& vch1 = stacktop(-2);
+ valtype& vch2 = stacktop(-1);
+ bool fEqual = (vch1 == vch2);
+ // OP_NOTEQUAL is disabled because it would be too easy to say
+ // something like n != 1 and have some wiseguy pass in 1 with extra
+ // zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001)
+ //if (opcode == OP_NOTEQUAL)
+ // fEqual = !fEqual;
+ popstack(stack);
+ popstack(stack);
+ stack.push_back(fEqual ? vchTrue : vchFalse);
+ if (opcode == OP_EQUALVERIFY)
+ {
+ if (fEqual)
+ popstack(stack);
+ else
+ return set_error(serror, SCRIPT_ERR_EQUALVERIFY);
+ }
+ }
+ break;
+
+
+ //
+ // Numeric
+ //
+ case OP_1ADD:
+ case OP_1SUB:
+ case OP_NEGATE:
+ case OP_ABS:
+ case OP_NOT:
+ case OP_0NOTEQUAL:
+ {
+ // (in -- out)
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ CScriptNum bn(stacktop(-1), fRequireMinimal);
+ switch (opcode)
+ {
+ case OP_1ADD: bn += bnOne; break;
+ case OP_1SUB: bn -= bnOne; break;
+ case OP_NEGATE: bn = -bn; break;
+ case OP_ABS: if (bn < bnZero) bn = -bn; break;
+ case OP_NOT: bn = (bn == bnZero); break;
+ case OP_0NOTEQUAL: bn = (bn != bnZero); break;
+ default: assert(!"invalid opcode"); break;
+ }
+ popstack(stack);
+ stack.push_back(bn.getvch());
+ }
+ break;
+
+ case OP_ADD:
+ case OP_SUB:
+ case OP_BOOLAND:
+ case OP_BOOLOR:
+ case OP_NUMEQUAL:
+ case OP_NUMEQUALVERIFY:
+ case OP_NUMNOTEQUAL:
+ case OP_LESSTHAN:
+ case OP_GREATERTHAN:
+ case OP_LESSTHANOREQUAL:
+ case OP_GREATERTHANOREQUAL:
+ case OP_MIN:
+ case OP_MAX:
+ {
+ // (x1 x2 -- out)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ CScriptNum bn1(stacktop(-2), fRequireMinimal);
+ CScriptNum bn2(stacktop(-1), fRequireMinimal);
+ CScriptNum bn(0);
+ switch (opcode)
+ {
+ case OP_ADD:
+ bn = bn1 + bn2;
+ break;
+
+ case OP_SUB:
+ bn = bn1 - bn2;
+ break;
+
+ case OP_BOOLAND: bn = (bn1 != bnZero && bn2 != bnZero); break;
+ case OP_BOOLOR: bn = (bn1 != bnZero || bn2 != bnZero); break;
+ case OP_NUMEQUAL: bn = (bn1 == bn2); break;
+ case OP_NUMEQUALVERIFY: bn = (bn1 == bn2); break;
+ case OP_NUMNOTEQUAL: bn = (bn1 != bn2); break;
+ case OP_LESSTHAN: bn = (bn1 < bn2); break;
+ case OP_GREATERTHAN: bn = (bn1 > bn2); break;
+ case OP_LESSTHANOREQUAL: bn = (bn1 <= bn2); break;
+ case OP_GREATERTHANOREQUAL: bn = (bn1 >= bn2); break;
+ case OP_MIN: bn = (bn1 < bn2 ? bn1 : bn2); break;
+ case OP_MAX: bn = (bn1 > bn2 ? bn1 : bn2); break;
+ default: assert(!"invalid opcode"); break;
+ }
+ popstack(stack);
+ popstack(stack);
+ stack.push_back(bn.getvch());
+
+ if (opcode == OP_NUMEQUALVERIFY)
+ {
+ if (CastToBool(stacktop(-1)))
+ popstack(stack);
+ else
+ return set_error(serror, SCRIPT_ERR_NUMEQUALVERIFY);
+ }
+ }
+ break;
+
+ case OP_WITHIN:
+ {
+ // (x min max -- out)
+ if (stack.size() < 3)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ CScriptNum bn1(stacktop(-3), fRequireMinimal);
+ CScriptNum bn2(stacktop(-2), fRequireMinimal);
+ CScriptNum bn3(stacktop(-1), fRequireMinimal);
+ bool fValue = (bn2 <= bn1 && bn1 < bn3);
+ popstack(stack);
+ popstack(stack);
+ popstack(stack);
+ stack.push_back(fValue ? vchTrue : vchFalse);
+ }
+ break;
+
+
+ //
+ // Crypto
+ //
+ case OP_RIPEMD160:
+ case OP_SHA1:
+ case OP_SHA256:
+ case OP_HASH160:
+ case OP_HASH256:
+ {
+ // (in -- hash)
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ valtype& vch = stacktop(-1);
+ valtype vchHash((opcode == OP_RIPEMD160 || opcode == OP_SHA1 || opcode == OP_HASH160) ? 20 : 32);
+ if (opcode == OP_RIPEMD160)
+ CRIPEMD160().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
+ else if (opcode == OP_SHA1)
+ CSHA1().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
+ else if (opcode == OP_SHA256)
+ CSHA256().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
+ else if (opcode == OP_HASH160)
+ CHash160().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
+ else if (opcode == OP_HASH256)
+ CHash256().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
+ popstack(stack);
+ stack.push_back(vchHash);
+ }
+ break;
+
+ case OP_CODESEPARATOR:
+ {
+ // Hash starts after the code separator
+ pbegincodehash = pc;
+ }
+ break;
+
+ case OP_CHECKSIG:
+ case OP_CHECKSIGVERIFY:
+ {
+ // (sig pubkey -- bool)
+ if (stack.size() < 2)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+
+ valtype& vchSig = stacktop(-2);
+ valtype& vchPubKey = stacktop(-1);
+
+ // Subset of script starting at the most recent codeseparator
+ CScript scriptCode(pbegincodehash, pend);
+
+ // Drop the signature, since there's no way for a signature to sign itself
+ scriptCode.FindAndDelete(CScript(vchSig));
+
+ if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, serror)) {
+ //serror is set
+ return false;
+ }
+ bool fSuccess = checker.CheckSig(vchSig, vchPubKey, scriptCode);
+
+ popstack(stack);
+ popstack(stack);
+ stack.push_back(fSuccess ? vchTrue : vchFalse);
+ if (opcode == OP_CHECKSIGVERIFY)
+ {
+ if (fSuccess)
+ popstack(stack);
+ else
+ return set_error(serror, SCRIPT_ERR_CHECKSIGVERIFY);
+ }
+ }
+ break;
+
+ case OP_CHECKMULTISIG:
+ case OP_CHECKMULTISIGVERIFY:
+ {
+ // ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool)
+
+ int i = 1;
+ if ((int)stack.size() < i)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+
+ int nKeysCount = CScriptNum(stacktop(-i), fRequireMinimal).getint();
+ if (nKeysCount < 0 || nKeysCount > MAX_PUBKEYS_PER_MULTISIG)
+ return set_error(serror, SCRIPT_ERR_PUBKEY_COUNT);
+ nOpCount += nKeysCount;
+ if (nOpCount > MAX_OPS_PER_SCRIPT)
+ return set_error(serror, SCRIPT_ERR_OP_COUNT);
+ int ikey = ++i;
+ i += nKeysCount;
+ if ((int)stack.size() < i)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+
+ int nSigsCount = CScriptNum(stacktop(-i), fRequireMinimal).getint();
+ if (nSigsCount < 0 || nSigsCount > nKeysCount)
+ return set_error(serror, SCRIPT_ERR_SIG_COUNT);
+ int isig = ++i;
+ i += nSigsCount;
+ if ((int)stack.size() < i)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+
+ // Subset of script starting at the most recent codeseparator
+ CScript scriptCode(pbegincodehash, pend);
+
+ // Drop the signatures, since there's no way for a signature to sign itself
+ for (int k = 0; k < nSigsCount; k++)
+ {
+ valtype& vchSig = stacktop(-isig-k);
+ scriptCode.FindAndDelete(CScript(vchSig));
+ }
+
+ bool fSuccess = true;
+ while (fSuccess && nSigsCount > 0)
+ {
+ valtype& vchSig = stacktop(-isig);
+ valtype& vchPubKey = stacktop(-ikey);
+
+ // Note how this makes the exact order of pubkey/signature evaluation
+ // distinguishable by CHECKMULTISIG NOT if the STRICTENC flag is set.
+ // See the script_(in)valid tests for details.
+ if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, serror)) {
+ // serror is set
+ return false;
+ }
+
+ // Check signature
+ bool fOk = checker.CheckSig(vchSig, vchPubKey, scriptCode);
+
+ if (fOk) {
+ isig++;
+ nSigsCount--;
+ }
+ ikey++;
+ nKeysCount--;
+
+ // If there are more signatures left than keys left,
+ // then too many signatures have failed. Exit early,
+ // without checking any further signatures.
+ if (nSigsCount > nKeysCount)
+ fSuccess = false;
+ }
+
+ // Clean up stack of actual arguments
+ while (i-- > 1)
+ popstack(stack);
+
+ // A bug causes CHECKMULTISIG to consume one extra argument
+ // whose contents were not checked in any way.
+ //
+ // Unfortunately this is a potential source of mutability,
+ // so optionally verify it is exactly equal to zero prior
+ // to removing it from the stack.
+ if (stack.size() < 1)
+ return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+ if ((flags & SCRIPT_VERIFY_NULLDUMMY) && stacktop(-1).size())
+ return set_error(serror, SCRIPT_ERR_SIG_NULLDUMMY);
+ popstack(stack);
+
+ stack.push_back(fSuccess ? vchTrue : vchFalse);
+
+ if (opcode == OP_CHECKMULTISIGVERIFY)
+ {
+ if (fSuccess)
+ popstack(stack);
+ else
+ return set_error(serror, SCRIPT_ERR_CHECKMULTISIGVERIFY);
+ }
+ }
+ break;
+
+ default:
+ return set_error(serror, SCRIPT_ERR_BAD_OPCODE);
+ }
+
+ // Size limits
+ if (stack.size() + altstack.size() > 1000)
+ return set_error(serror, SCRIPT_ERR_STACK_SIZE);
+ }
+ }
+ catch (...)
+ {
+ return set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);
+ }
+
+ if (!vfExec.empty())
+ return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL);
+
+ return set_success(serror);
+}
+
+namespace {
+
+/**
+ * Wrapper that serializes like CTransaction, but with the modifications
+ * required for the signature hash done in-place
+ */
+class CTransactionSignatureSerializer {
+private:
+ const CTransaction &txTo; //! reference to the spending transaction (the one being serialized)
+ const CScript &scriptCode; //! output script being consumed
+ const unsigned int nIn; //! input index of txTo being signed
+ const bool fAnyoneCanPay; //! whether the hashtype has the SIGHASH_ANYONECANPAY flag set
+ const bool fHashSingle; //! whether the hashtype is SIGHASH_SINGLE
+ const bool fHashNone; //! whether the hashtype is SIGHASH_NONE
+
+public:
+ CTransactionSignatureSerializer(const CTransaction &txToIn, const CScript &scriptCodeIn, unsigned int nInIn, int nHashTypeIn) :
+ txTo(txToIn), scriptCode(scriptCodeIn), nIn(nInIn),
+ fAnyoneCanPay(!!(nHashTypeIn & SIGHASH_ANYONECANPAY)),
+ fHashSingle((nHashTypeIn & 0x1f) == SIGHASH_SINGLE),
+ fHashNone((nHashTypeIn & 0x1f) == SIGHASH_NONE) {}
+
+ /** Serialize the passed scriptCode, skipping OP_CODESEPARATORs */
+ template<typename S>
+ void SerializeScriptCode(S &s, int nType, int nVersion) const {
+ CScript::const_iterator it = scriptCode.begin();
+ CScript::const_iterator itBegin = it;
+ opcodetype opcode;
+ unsigned int nCodeSeparators = 0;
+ while (scriptCode.GetOp(it, opcode)) {
+ if (opcode == OP_CODESEPARATOR)
+ nCodeSeparators++;
+ }
+ ::WriteCompactSize(s, scriptCode.size() - nCodeSeparators);
+ it = itBegin;
+ while (scriptCode.GetOp(it, opcode)) {
+ if (opcode == OP_CODESEPARATOR) {
+ s.write((char*)&itBegin[0], it-itBegin-1);
+ itBegin = it;
+ }
+ }
+ if (itBegin != scriptCode.end())
+ s.write((char*)&itBegin[0], it-itBegin);
+ }
+
+ /** Serialize an input of txTo */
+ template<typename S>
+ void SerializeInput(S &s, unsigned int nInput, int nType, int nVersion) const {
+ // In case of SIGHASH_ANYONECANPAY, only the input being signed is serialized
+ if (fAnyoneCanPay)
+ nInput = nIn;
+ // Serialize the prevout
+ ::Serialize(s, txTo.vin[nInput].prevout, nType, nVersion);
+ // Serialize the script
+ if (nInput != nIn)
+ // Blank out other inputs' signatures
+ ::Serialize(s, CScript(), nType, nVersion);
+ else
+ SerializeScriptCode(s, nType, nVersion);
+ // Serialize the nSequence
+ if (nInput != nIn && (fHashSingle || fHashNone))
+ // let the others update at will
+ ::Serialize(s, (int)0, nType, nVersion);
+ else
+ ::Serialize(s, txTo.vin[nInput].nSequence, nType, nVersion);
+ }
+
+ /** Serialize an output of txTo */
+ template<typename S>
+ void SerializeOutput(S &s, unsigned int nOutput, int nType, int nVersion) const {
+ if (fHashSingle && nOutput != nIn)
+ // Do not lock-in the txout payee at other indices as txin
+ ::Serialize(s, CTxOut(), nType, nVersion);
+ else
+ ::Serialize(s, txTo.vout[nOutput], nType, nVersion);
+ }
+
+ /** Serialize txTo */
+ template<typename S>
+ void Serialize(S &s, int nType, int nVersion) const {
+ // Serialize nVersion
+ ::Serialize(s, txTo.nVersion, nType, nVersion);
+ // Serialize vin
+ unsigned int nInputs = fAnyoneCanPay ? 1 : txTo.vin.size();
+ ::WriteCompactSize(s, nInputs);
+ for (unsigned int nInput = 0; nInput < nInputs; nInput++)
+ SerializeInput(s, nInput, nType, nVersion);
+ // Serialize vout
+ unsigned int nOutputs = fHashNone ? 0 : (fHashSingle ? nIn+1 : txTo.vout.size());
+ ::WriteCompactSize(s, nOutputs);
+ for (unsigned int nOutput = 0; nOutput < nOutputs; nOutput++)
+ SerializeOutput(s, nOutput, nType, nVersion);
+ // Serialize nLockTime
+ ::Serialize(s, txTo.nLockTime, nType, nVersion);
+ }
+};
+
+} // anon namespace
+
+uint256 SignatureHash(const CScript& scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType)
+{
+ static const uint256 one(uint256S("0000000000000000000000000000000000000000000000000000000000000001"));
+ if (nIn >= txTo.vin.size()) {
+ // nIn out of range
+ return one;
+ }
+
+ // Check for invalid use of SIGHASH_SINGLE
+ if ((nHashType & 0x1f) == SIGHASH_SINGLE) {
+ if (nIn >= txTo.vout.size()) {
+ // nOut out of range
+ return one;
+ }
+ }
+
+ // Wrapper to serialize only the necessary parts of the transaction being signed
+ CTransactionSignatureSerializer txTmp(txTo, scriptCode, nIn, nHashType);
+
+ // Serialize and hash
+ CHashWriter ss(SER_GETHASH, 0);
+ ss << txTmp << nHashType;
+ return ss.GetHash();
+}
+
+bool TransactionSignatureChecker::VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& pubkey, const uint256& sighash) const
+{
+ return pubkey.Verify(sighash, vchSig);
+}
+
+bool TransactionSignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn, const vector<unsigned char>& vchPubKey, const CScript& scriptCode) const
+{
+ CPubKey pubkey(vchPubKey);
+ if (!pubkey.IsValid())
+ return false;
+
+ // Hash type is one byte tacked on to the end of the signature
+ vector<unsigned char> vchSig(vchSigIn);
+ if (vchSig.empty())
+ return false;
+ int nHashType = vchSig.back();
+ vchSig.pop_back();
+
+ uint256 sighash = SignatureHash(scriptCode, *txTo, nIn, nHashType);
+
+ if (!VerifySignature(vchSig, pubkey, sighash))
+ return false;
+
+ return true;
+}
+
+bool TransactionSignatureChecker::CheckLockTime(const CScriptNum& nLockTime) const
+{
+ // There are two kinds of nLockTime: lock-by-blockheight
+ // and lock-by-blocktime, distinguished by whether
+ // nLockTime < LOCKTIME_THRESHOLD.
+ //
+ // We want to compare apples to apples, so fail the script
+ // unless the type of nLockTime being tested is the same as
+ // the nLockTime in the transaction.
+ if (!(
+ (txTo->nLockTime < LOCKTIME_THRESHOLD && nLockTime < LOCKTIME_THRESHOLD) ||
+ (txTo->nLockTime >= LOCKTIME_THRESHOLD && nLockTime >= LOCKTIME_THRESHOLD)
+ ))
+ return false;
+
+ // Now that we know we're comparing apples-to-apples, the
+ // comparison is a simple numeric one.
+ if (nLockTime > (int64_t)txTo->nLockTime)
+ return false;
+
+ // Finally the nLockTime feature can be disabled and thus
+ // CHECKLOCKTIMEVERIFY bypassed if every txin has been
+ // finalized by setting nSequence to maxint. The
+ // transaction would be allowed into the blockchain, making
+ // the opcode ineffective.
+ //
+ // Testing if this vin is not final is sufficient to
+ // prevent this condition. Alternatively we could test all
+ // inputs, but testing just this input minimizes the data
+ // required to prove correct CHECKLOCKTIMEVERIFY execution.
+ if (txTo->vin[nIn].IsFinal())
+ return false;
+
+ return true;
+}
+
+
+bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror)
+{
+ set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);
+
+ if ((flags & SCRIPT_VERIFY_SIGPUSHONLY) != 0 && !scriptSig.IsPushOnly()) {
+ return set_error(serror, SCRIPT_ERR_SIG_PUSHONLY);
+ }
+
+ vector<vector<unsigned char> > stack, stackCopy;
+ if (!EvalScript(stack, scriptSig, flags, checker, serror))
+ // serror is set
+ return false;
+ if (flags & SCRIPT_VERIFY_P2SH)
+ stackCopy = stack;
+ if (!EvalScript(stack, scriptPubKey, flags, checker, serror))
+ // serror is set
+ return false;
+ if (stack.empty())
+ return set_error(serror, SCRIPT_ERR_EVAL_FALSE);
+ if (CastToBool(stack.back()) == false)
+ return set_error(serror, SCRIPT_ERR_EVAL_FALSE);
+
+ // Additional validation for spend-to-script-hash transactions:
+ if ((flags & SCRIPT_VERIFY_P2SH) && scriptPubKey.IsPayToScriptHash())
+ {
+ // scriptSig must be literals-only or validation fails
+ if (!scriptSig.IsPushOnly())
+ return set_error(serror, SCRIPT_ERR_SIG_PUSHONLY);
+
+ // Restore stack.
+ swap(stack, stackCopy);
+
+ // stack cannot be empty here, because if it was the
+ // P2SH HASH <> EQUAL scriptPubKey would be evaluated with
+ // an empty stack and the EvalScript above would return false.
+ assert(!stack.empty());
+
+ const valtype& pubKeySerialized = stack.back();
+ CScript pubKey2(pubKeySerialized.begin(), pubKeySerialized.end());
+ popstack(stack);
+
+ if (!EvalScript(stack, pubKey2, flags, checker, serror))
+ // serror is set
+ return false;
+ if (stack.empty())
+ return set_error(serror, SCRIPT_ERR_EVAL_FALSE);
+ if (!CastToBool(stack.back()))
+ return set_error(serror, SCRIPT_ERR_EVAL_FALSE);
+ }
+
+ // The CLEANSTACK check is only performed after potential P2SH evaluation,
+ // as the non-P2SH evaluation of a P2SH script will obviously not result in
+ // a clean stack (the P2SH inputs remain).
+ if ((flags & SCRIPT_VERIFY_CLEANSTACK) != 0) {
+ // Disallow CLEANSTACK without P2SH, as otherwise a switch CLEANSTACK->P2SH+CLEANSTACK
+ // would be possible, which is not a softfork (and P2SH should be one).
+ assert((flags & SCRIPT_VERIFY_P2SH) != 0);
+ if (stack.size() != 1) {
+ return set_error(serror, SCRIPT_ERR_CLEANSTACK);
+ }
+ }
+
+ return set_success(serror);
+}
generated by cgit v1.2.3 (git 2.26.2) at 2025-03-21 18:49:20 +0000