Implement additional script verification flags

[novacoin.git] / src / script.h

diff --git a/src/script.h b/src/script.h
index 8901981..7cc5f1d 100644 (file)
--- a/src/script.h
+++ b/src/script.h
@@ -18,6 +18,8 @@ typedef std::vector<unsigned char> valtype;
 
 class CTransaction;
 
+static const unsigned int MAX_SCRIPT_ELEMENT_SIZE = 520; // bytes
+
 /** Signature hash types/flags */
 enum
 {
@@ -27,6 +29,35 @@ enum
     SIGHASH_ANYONECANPAY = 0x80,
 };
 
+/** Script verification flags */
+enum
+{
+    SCRIPT_VERIFY_NONE      = 0,
+    SCRIPT_VERIFY_P2SH      = (1U << 0), // evaluate P2SH (BIP16) subscripts
+    SCRIPT_VERIFY_STRICTENC = (1U << 1), // enforce strict conformance to DER and SEC2 for signatures and pubkeys
+    SCRIPT_VERIFY_EVEN_S    = (1U << 2), // enforce even S values in signatures (depends on STRICTENC)
+    SCRIPT_VERIFY_NOCACHE   = (1U << 3), // do not store results in signature cache (but do query it)
+    SCRIPT_VERIFY_NULLDUMMY = (1U << 4), // verify dummy stack item consumed by CHECKMULTISIG is of zero-length
+};
+
+// 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;
+
+// Standard script verification flags that standard transactions will comply
+// with. However scripts violating these flags may still be present in valid
+// blocks and we must accept those blocks.
+static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS |
+                                                         SCRIPT_VERIFY_STRICTENC |
+                                                         SCRIPT_VERIFY_NULLDUMMY;
+
+// For convenience, standard but not mandatory verify flags.
+static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
 
 enum txnouttype
 {
@@ -585,11 +616,11 @@ public:
     }
 };
 
+bool IsCanonicalPubKey(const std::vector<unsigned char> &vchPubKey, unsigned int flags);
+bool IsCanonicalSignature(const std::vector<unsigned char> &vchSig, unsigned int flags);
 
 
-
-
-bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, int nHashType);
+bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType);
 bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<std::vector<unsigned char> >& vSolutionsRet);
 int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions);
 bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType);
@@ -600,9 +631,8 @@ bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
 bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);
 bool SignSignature(const CKeyStore& keystore, const CScript& fromPubKey, CTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
 bool SignSignature(const CKeyStore& keystore, const CTransaction& txFrom, CTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL);
-bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn,
-                  bool fValidatePayToScriptHash, int nHashType);
-bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, bool fValidatePayToScriptHash, int nHashType);
+bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType);
+bool VerifySignature(const CTransaction& txFrom, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType);
 
 // Given two sets of signatures for scriptPubKey, possibly with OP_0 placeholders,
 // combine them intelligently and return the result.