aboutsummaryrefslogtreecommitdiff
path: root/src/script
diff options
context:
space:
mode:
Diffstat (limited to 'src/script')
-rw-r--r--src/script/compressor.cpp130
-rw-r--r--src/script/compressor.h89
-rw-r--r--src/script/interpreter.cpp57
-rw-r--r--src/script/interpreter.h10
-rw-r--r--src/script/script.cpp31
-rw-r--r--src/script/script.h35
-rw-r--r--src/script/sign.cpp2
-rw-r--r--src/script/standard.h1
8 files changed, 86 insertions, 269 deletions
diff --git a/src/script/compressor.cpp b/src/script/compressor.cpp
deleted file mode 100644
index af1acf48db..0000000000
--- a/src/script/compressor.cpp
+++ /dev/null
@@ -1,130 +0,0 @@
-// Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2014 The Bitcoin developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#include "compressor.h"
-
-#include "key.h"
-#include "script/standard.h"
-
-bool CScriptCompressor::IsToKeyID(CKeyID &hash) const
-{
- if (script.size() == 25 && script[0] == OP_DUP && script[1] == OP_HASH160
- && script[2] == 20 && script[23] == OP_EQUALVERIFY
- && script[24] == OP_CHECKSIG) {
- memcpy(&hash, &script[3], 20);
- return true;
- }
- return false;
-}
-
-bool CScriptCompressor::IsToScriptID(CScriptID &hash) const
-{
- if (script.size() == 23 && script[0] == OP_HASH160 && script[1] == 20
- && script[22] == OP_EQUAL) {
- memcpy(&hash, &script[2], 20);
- return true;
- }
- return false;
-}
-
-bool CScriptCompressor::IsToPubKey(CPubKey &pubkey) const
-{
- if (script.size() == 35 && script[0] == 33 && script[34] == OP_CHECKSIG
- && (script[1] == 0x02 || script[1] == 0x03)) {
- pubkey.Set(&script[1], &script[34]);
- return true;
- }
- if (script.size() == 67 && script[0] == 65 && script[66] == OP_CHECKSIG
- && script[1] == 0x04) {
- pubkey.Set(&script[1], &script[66]);
- return pubkey.IsFullyValid(); // if not fully valid, a case that would not be compressible
- }
- return false;
-}
-
-bool CScriptCompressor::Compress(std::vector<unsigned char> &out) const
-{
- CKeyID keyID;
- if (IsToKeyID(keyID)) {
- out.resize(21);
- out[0] = 0x00;
- memcpy(&out[1], &keyID, 20);
- return true;
- }
- CScriptID scriptID;
- if (IsToScriptID(scriptID)) {
- out.resize(21);
- out[0] = 0x01;
- memcpy(&out[1], &scriptID, 20);
- return true;
- }
- CPubKey pubkey;
- if (IsToPubKey(pubkey)) {
- out.resize(33);
- memcpy(&out[1], &pubkey[1], 32);
- if (pubkey[0] == 0x02 || pubkey[0] == 0x03) {
- out[0] = pubkey[0];
- return true;
- } else if (pubkey[0] == 0x04) {
- out[0] = 0x04 | (pubkey[64] & 0x01);
- return true;
- }
- }
- return false;
-}
-
-unsigned int CScriptCompressor::GetSpecialSize(unsigned int nSize) const
-{
- if (nSize == 0 || nSize == 1)
- return 20;
- if (nSize == 2 || nSize == 3 || nSize == 4 || nSize == 5)
- return 32;
- return 0;
-}
-
-bool CScriptCompressor::Decompress(unsigned int nSize, const std::vector<unsigned char> &in)
-{
- switch(nSize) {
- case 0x00:
- script.resize(25);
- script[0] = OP_DUP;
- script[1] = OP_HASH160;
- script[2] = 20;
- memcpy(&script[3], &in[0], 20);
- script[23] = OP_EQUALVERIFY;
- script[24] = OP_CHECKSIG;
- return true;
- case 0x01:
- script.resize(23);
- script[0] = OP_HASH160;
- script[1] = 20;
- memcpy(&script[2], &in[0], 20);
- script[22] = OP_EQUAL;
- return true;
- case 0x02:
- case 0x03:
- script.resize(35);
- script[0] = 33;
- script[1] = nSize;
- memcpy(&script[2], &in[0], 32);
- script[34] = OP_CHECKSIG;
- return true;
- case 0x04:
- case 0x05:
- unsigned char vch[33] = {};
- vch[0] = nSize - 2;
- memcpy(&vch[1], &in[0], 32);
- CPubKey pubkey(&vch[0], &vch[33]);
- if (!pubkey.Decompress())
- return false;
- assert(pubkey.size() == 65);
- script.resize(67);
- script[0] = 65;
- memcpy(&script[1], pubkey.begin(), 65);
- script[66] = OP_CHECKSIG;
- return true;
- }
- return false;
-}
diff --git a/src/script/compressor.h b/src/script/compressor.h
deleted file mode 100644
index 154e0b2662..0000000000
--- a/src/script/compressor.h
+++ /dev/null
@@ -1,89 +0,0 @@
-// Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2014 The Bitcoin developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#ifndef H_BITCOIN_SCRIPT_COMPRESSOR
-#define H_BITCOIN_SCRIPT_COMPRESSOR
-
-#include "script/script.h"
-#include "serialize.h"
-
-class CKeyID;
-class CPubKey;
-class CScriptID;
-
-/** Compact serializer for scripts.
- *
- * It detects common cases and encodes them much more efficiently.
- * 3 special cases are defined:
- * * Pay to pubkey hash (encoded as 21 bytes)
- * * Pay to script hash (encoded as 21 bytes)
- * * Pay to pubkey starting with 0x02, 0x03 or 0x04 (encoded as 33 bytes)
- *
- * Other scripts up to 121 bytes require 1 byte + script length. Above
- * that, scripts up to 16505 bytes require 2 bytes + script length.
- */
-class CScriptCompressor
-{
-private:
- // make this static for now (there are only 6 special scripts defined)
- // this can potentially be extended together with a new nVersion for
- // transactions, in which case this value becomes dependent on nVersion
- // and nHeight of the enclosing transaction.
- static const unsigned int nSpecialScripts = 6;
-
- CScript &script;
-protected:
- // These check for scripts for which a special case with a shorter encoding is defined.
- // They are implemented separately from the CScript test, as these test for exact byte
- // sequence correspondences, and are more strict. For example, IsToPubKey also verifies
- // whether the public key is valid (as invalid ones cannot be represented in compressed
- // form).
- bool IsToKeyID(CKeyID &hash) const;
- bool IsToScriptID(CScriptID &hash) const;
- bool IsToPubKey(CPubKey &pubkey) const;
-
- bool Compress(std::vector<unsigned char> &out) const;
- unsigned int GetSpecialSize(unsigned int nSize) const;
- bool Decompress(unsigned int nSize, const std::vector<unsigned char> &out);
-public:
- CScriptCompressor(CScript &scriptIn) : script(scriptIn) { }
-
- unsigned int GetSerializeSize(int nType, int nVersion) const {
- std::vector<unsigned char> compr;
- if (Compress(compr))
- return compr.size();
- unsigned int nSize = script.size() + nSpecialScripts;
- return script.size() + VARINT(nSize).GetSerializeSize(nType, nVersion);
- }
-
- template<typename Stream>
- void Serialize(Stream &s, int nType, int nVersion) const {
- std::vector<unsigned char> compr;
- if (Compress(compr)) {
- s << CFlatData(compr);
- return;
- }
- unsigned int nSize = script.size() + nSpecialScripts;
- s << VARINT(nSize);
- s << CFlatData(script);
- }
-
- template<typename Stream>
- void Unserialize(Stream &s, int nType, int nVersion) {
- unsigned int nSize = 0;
- s >> VARINT(nSize);
- if (nSize < nSpecialScripts) {
- std::vector<unsigned char> vch(GetSpecialSize(nSize), 0x00);
- s >> REF(CFlatData(vch));
- Decompress(nSize, vch);
- return;
- }
- nSize -= nSpecialScripts;
- script.resize(nSize);
- s >> REF(CFlatData(script));
- }
-};
-
-#endif // H_BITCOIN_SCRIPT_COMPRESSOR
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index cd73b88210..3625972ebf 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -5,7 +5,7 @@
#include "interpreter.h"
-#include "core.h"
+#include "core/transaction.h"
#include "crypto/ripemd160.h"
#include "crypto/sha1.h"
#include "crypto/sha2.h"
@@ -157,6 +157,29 @@ bool static CheckPubKeyEncoding(const valtype &vchSig, unsigned int flags) {
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)
{
CScript::const_iterator pc = script.begin();
@@ -169,6 +192,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
if (script.size() > 10000)
return false;
int nOpCount = 0;
+ bool fRequireMinimal = (flags & SCRIPT_VERIFY_MINIMALDATA) != 0;
try
{
@@ -205,9 +229,12 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
opcode == OP_RSHIFT)
return false; // Disabled opcodes.
- if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4)
+ if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4) {
+ if (fRequireMinimal && !CheckMinimalPush(vchPushValue, opcode)) {
+ return false;
+ }
stack.push_back(vchPushValue);
- else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))
+ } else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))
switch (opcode)
{
//
@@ -234,6 +261,8 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
// ( -- 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;
@@ -458,7 +487,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
// (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)
if (stack.size() < 2)
return false;
- int n = CScriptNum(stacktop(-1)).getint();
+ int n = CScriptNum(stacktop(-1), fRequireMinimal).getint();
popstack(stack);
if (n < 0 || n >= (int)stack.size())
return false;
@@ -557,7 +586,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
// (in -- out)
if (stack.size() < 1)
return false;
- CScriptNum bn(stacktop(-1));
+ CScriptNum bn(stacktop(-1), fRequireMinimal);
switch (opcode)
{
case OP_1ADD: bn += bnOne; break;
@@ -590,8 +619,8 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
// (x1 x2 -- out)
if (stack.size() < 2)
return false;
- CScriptNum bn1(stacktop(-2));
- CScriptNum bn2(stacktop(-1));
+ CScriptNum bn1(stacktop(-2), fRequireMinimal);
+ CScriptNum bn2(stacktop(-1), fRequireMinimal);
CScriptNum bn(0);
switch (opcode)
{
@@ -635,9 +664,9 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
// (x min max -- out)
if (stack.size() < 3)
return false;
- CScriptNum bn1(stacktop(-3));
- CScriptNum bn2(stacktop(-2));
- CScriptNum bn3(stacktop(-1));
+ 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);
@@ -727,7 +756,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
if ((int)stack.size() < i)
return false;
- int nKeysCount = CScriptNum(stacktop(-i)).getint();
+ int nKeysCount = CScriptNum(stacktop(-i), fRequireMinimal).getint();
if (nKeysCount < 0 || nKeysCount > 20)
return false;
nOpCount += nKeysCount;
@@ -738,7 +767,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
if ((int)stack.size() < i)
return false;
- int nSigsCount = CScriptNum(stacktop(-i)).getint();
+ int nSigsCount = CScriptNum(stacktop(-i), fRequireMinimal).getint();
if (nSigsCount < 0 || nSigsCount > nKeysCount)
return false;
int isig = ++i;
@@ -980,6 +1009,10 @@ bool SignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn, const vec
bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker)
{
+ if ((flags & SCRIPT_VERIFY_SIGPUSHONLY) != 0 && !scriptSig.IsPushOnly()) {
+ return false;
+ }
+
vector<vector<unsigned char> > stack, stackCopy;
if (!EvalScript(stack, scriptSig, flags, checker))
return false;
diff --git a/src/script/interpreter.h b/src/script/interpreter.h
index de5ce2ced1..5133c80aab 100644
--- a/src/script/interpreter.h
+++ b/src/script/interpreter.h
@@ -46,6 +46,16 @@ enum
// 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)
};
uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType);
diff --git a/src/script/script.cpp b/src/script/script.cpp
index 3e19d0c2bf..b879d72d6b 100644
--- a/src/script/script.cpp
+++ b/src/script/script.cpp
@@ -12,7 +12,7 @@ namespace {
inline std::string ValueString(const std::vector<unsigned char>& vch)
{
if (vch.size() <= 4)
- return strprintf("%d", CScriptNum(vch).getint());
+ return strprintf("%d", CScriptNum(vch, false).getint());
else
return HexStr(vch);
}
@@ -230,7 +230,7 @@ bool CScript::IsPushOnly() const
return false;
// Note that IsPushOnly() *does* consider OP_RESERVED to be a
// push-type opcode, however execution of OP_RESERVED fails, so
- // it's not relevant to P2SH as the scriptSig would fail prior to
+ // it's not relevant to P2SH/BIP62 as the scriptSig would fail prior to
// the P2SH special validation code being executed.
if (opcode > OP_16)
return false;
@@ -238,33 +238,6 @@ bool CScript::IsPushOnly() const
return true;
}
-bool CScript::HasCanonicalPushes() const
-{
- const_iterator pc = begin();
- while (pc < end())
- {
- opcodetype opcode;
- std::vector<unsigned char> data;
- if (!GetOp(pc, opcode, data))
- return false;
- if (opcode > OP_16)
- continue;
- if (opcode < OP_PUSHDATA1 && opcode > OP_0 && (data.size() == 1 && data[0] <= 16))
- // Could have used an OP_n code, rather than a 1-byte push.
- return false;
- if (opcode == OP_PUSHDATA1 && data.size() < OP_PUSHDATA1)
- // Could have used a normal n-byte push, rather than OP_PUSHDATA1.
- return false;
- if (opcode == OP_PUSHDATA2 && data.size() <= 0xFF)
- // Could have used an OP_PUSHDATA1.
- return false;
- if (opcode == OP_PUSHDATA4 && data.size() <= 0xFFFF)
- // Could have used an OP_PUSHDATA2.
- return false;
- }
- return true;
-}
-
std::string CScript::ToString() const
{
std::string str;
diff --git a/src/script/script.h b/src/script/script.h
index d450db5cad..05f2e7e3a9 100644
--- a/src/script/script.h
+++ b/src/script/script.h
@@ -192,10 +192,29 @@ public:
m_value = n;
}
- explicit CScriptNum(const std::vector<unsigned char>& vch)
+ explicit CScriptNum(const std::vector<unsigned char>& vch, bool fRequireMinimal)
{
- if (vch.size() > nMaxNumSize)
- throw scriptnum_error("CScriptNum(const std::vector<unsigned char>&) : overflow");
+ if (vch.size() > nMaxNumSize) {
+ throw scriptnum_error("script number overflow");
+ }
+ if (fRequireMinimal && vch.size() > 0) {
+ // Check that the number is encoded with the minimum possible
+ // number of bytes.
+ //
+ // If the most-significant-byte - excluding the sign bit - is zero
+ // then we're not minimal. Note how this test also rejects the
+ // negative-zero encoding, 0x80.
+ if ((vch.back() & 0x7f) == 0) {
+ // One exception: if there's more than one byte and the most
+ // significant bit of the second-most-significant-byte is set
+ // it would conflict with the sign bit. An example of this case
+ // is +-255, which encode to 0xff00 and 0xff80 respectively.
+ // (big-endian).
+ if (vch.size() <= 1 || (vch[vch.size() - 2] & 0x80) == 0) {
+ throw scriptnum_error("non-minimally encoded script number");
+ }
+ }
+ }
m_value = set_vch(vch);
}
@@ -319,7 +338,6 @@ private:
int64_t m_value;
};
-
/** Serialized script, used inside transaction inputs and outputs */
class CScript : public std::vector<unsigned char>
{
@@ -330,6 +348,10 @@ protected:
{
push_back(n + (OP_1 - 1));
}
+ else if (n == 0)
+ {
+ push_back(OP_0);
+ }
else
{
*this << CScriptNum::serialize(n);
@@ -551,12 +573,9 @@ public:
bool IsPayToScriptHash() const;
- // Called by IsStandardTx and P2SH VerifyScript (which makes it consensus-critical).
+ // Called by IsStandardTx and P2SH/BIP62 VerifyScript (which makes it consensus-critical).
bool IsPushOnly() const;
- // Called by IsStandardTx.
- bool HasCanonicalPushes() const;
-
// Returns whether the script is guaranteed to fail at execution,
// regardless of the initial stack. This allows outputs to be pruned
// instantly when entering the UTXO set.
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index bf98c40394..0eab0626e5 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -5,7 +5,7 @@
#include "script/sign.h"
-#include "core.h"
+#include "core/transaction.h"
#include "key.h"
#include "keystore.h"
#include "script/standard.h"
diff --git a/src/script/standard.h b/src/script/standard.h
index d795121e3c..504d98c686 100644
--- a/src/script/standard.h
+++ b/src/script/standard.h
@@ -42,6 +42,7 @@ static const unsigned int MANDATORY_SCRIPT_VERIFY_FLAGS = SCRIPT_VERIFY_P2SH;
// blocks and we must accept those blocks.
static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS |
SCRIPT_VERIFY_STRICTENC |
+ SCRIPT_VERIFY_MINIMALDATA |
SCRIPT_VERIFY_NULLDUMMY;
// For convenience, standard but not mandatory verify flags.
generated by cgit v1.2.3 (git 2.26.2) at 2024-08-25 11:43:06 +0000