diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp index 54c2847f79a..5fda6248c2e 100644 --- a/src/script/interpreter.cpp +++ b/src/script/interpreter.cpp @@ -41,10 +41,10 @@ bool CastToBool(const valtype& vch) return false; } -// -// Script is a stack machine (like Forth) that evaluates a predicate -// returning a bool indicating valid or not. There are no loops. -// +/** + * 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& stack) @@ -69,12 +69,16 @@ bool static IsCompressedOrUncompressedPubKey(const valtype &vchPubKey) { return true; } +/** + * A canonical signature exists of: <30> <02> <02> + * 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 + */ bool static IsDERSignature(const valtype &vchSig) { - // See https://bitcointalk.org/index.php?topic=8392.msg127623#msg127623 - // A canonical signature exists of: <30> <02> <02> - // 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). + if (vchSig.size() < 9) return error("Non-canonical signature: too short"); if (vchSig.size() > 73) @@ -862,17 +866,18 @@ bool EvalScript(vector >& stack, const CScript& script, un namespace { -/** Wrapper that serializes like CTransaction, but with the modifications +/** + * 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 + 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) : @@ -951,7 +956,7 @@ public: ::WriteCompactSize(s, nOutputs); for (unsigned int nOutput = 0; nOutput < nOutputs; nOutput++) SerializeOutput(s, nOutput, nType, nVersion); - // Serialie nLockTime + // Serialize nLockTime ::Serialize(s, txTo.nLockTime, nType, nVersion); } }; diff --git a/src/script/script.h b/src/script/script.h index e525ad13ee8..9c22cb908cf 100644 --- a/src/script/script.h +++ b/src/script/script.h @@ -179,12 +179,14 @@ public: class CScriptNum { -// Numeric opcodes (OP_1ADD, etc) are restricted to operating on 4-byte integers. -// The semantics are subtle, though: operands must be in the range [-2^31 +1...2^31 -1], -// but results may overflow (and are valid as long as they are not used in a subsequent -// numeric operation). CScriptNum enforces those semantics by storing results as -// an int64 and allowing out-of-range values to be returned as a vector of bytes but -// throwing an exception if arithmetic is done or the result is interpreted as an integer. +/** + * Numeric opcodes (OP_1ADD, etc) are restricted to operating on 4-byte integers. + * The semantics are subtle, though: operands must be in the range [-2^31 +1...2^31 -1], + * but results may overflow (and are valid as long as they are not used in a subsequent + * numeric operation). CScriptNum enforces those semantics by storing results as + * an int64 and allowing out-of-range values to be returned as a vector of bytes but + * throwing an exception if arithmetic is done or the result is interpreted as an integer. + */ public: explicit CScriptNum(const int64_t& n) @@ -516,7 +518,7 @@ public: return true; } - // Encode/decode small integers: + /** Encode/decode small integers: */ static int DecodeOP_N(opcodetype opcode) { if (opcode == OP_0) @@ -560,25 +562,31 @@ public: return nFound; } - // Pre-version-0.6, Bitcoin always counted CHECKMULTISIGs - // as 20 sigops. With pay-to-script-hash, that changed: - // CHECKMULTISIGs serialized in scriptSigs are - // counted more accurately, assuming they are of the form - // ... OP_N CHECKMULTISIG ... + /** + * Pre-version-0.6, Bitcoin always counted CHECKMULTISIGs + * as 20 sigops. With pay-to-script-hash, that changed: + * CHECKMULTISIGs serialized in scriptSigs are + * counted more accurately, assuming they are of the form + * ... OP_N CHECKMULTISIG ... + */ unsigned int GetSigOpCount(bool fAccurate) const; - // Accurately count sigOps, including sigOps in - // pay-to-script-hash transactions: + /** + * Accurately count sigOps, including sigOps in + * pay-to-script-hash transactions: + */ unsigned int GetSigOpCount(const CScript& scriptSig) const; bool IsPayToScriptHash() const; - // Called by IsStandardTx and P2SH/BIP62 VerifyScript (which makes it consensus-critical). + /** Called by IsStandardTx and P2SH/BIP62 VerifyScript (which makes it consensus-critical). */ bool IsPushOnly() 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. + /** + * 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. + */ bool IsUnspendable() const { return (size() > 0 && *begin() == OP_RETURN); diff --git a/src/script/sigcache.cpp b/src/script/sigcache.cpp index d76a5acd636..5580a5933e6 100644 --- a/src/script/sigcache.cpp +++ b/src/script/sigcache.cpp @@ -15,13 +15,15 @@ namespace { -// Valid signature cache, to avoid doing expensive ECDSA signature checking -// twice for every transaction (once when accepted into memory pool, and -// again when accepted into the block chain) +/** + * Valid signature cache, to avoid doing expensive ECDSA signature checking + * twice for every transaction (once when accepted into memory pool, and + * again when accepted into the block chain) + */ class CSignatureCache { private: - // sigdata_type is (signature hash, signature, public key): + //! sigdata_type is (signature hash, signature, public key): typedef boost::tuple, CPubKey> sigdata_type; std::set< sigdata_type> setValid; boost::shared_mutex cs_sigcache; diff --git a/src/script/sign.cpp b/src/script/sign.cpp index 9dfd640dfb2..7dfed751b6b 100644 --- a/src/script/sign.cpp +++ b/src/script/sign.cpp @@ -46,12 +46,12 @@ bool SignN(const vector& multisigdata, const CKeyStore& keystore, uint2 return nSigned==nRequired; } -// -// Sign scriptPubKey with private keys stored in keystore, given transaction hash and hash type. -// Signatures are returned in scriptSigRet (or returns false if scriptPubKey can't be signed), -// unless whichTypeRet is TX_SCRIPTHASH, in which case scriptSigRet is the redemption script. -// Returns false if scriptPubKey could not be completely satisfied. -// +/** + * Sign scriptPubKey with private keys stored in keystore, given transaction hash and hash type. + * Signatures are returned in scriptSigRet (or returns false if scriptPubKey can't be signed), + * unless whichTypeRet is TX_SCRIPTHASH, in which case scriptSigRet is the redemption script. + * Returns false if scriptPubKey could not be completely satisfied. + */ bool Solver(const CKeyStore& keystore, const CScript& scriptPubKey, uint256 hash, int nHashType, CScript& scriptSigRet, txnouttype& whichTypeRet) { diff --git a/src/script/sign.h b/src/script/sign.h index 99d5516adb5..45a5e0dea33 100644 --- a/src/script/sign.h +++ b/src/script/sign.h @@ -17,8 +17,10 @@ struct CMutableTransaction; bool SignSignature(const CKeyStore& keystore, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL); bool SignSignature(const CKeyStore& keystore, const CTransaction& txFrom, CMutableTransaction& txTo, unsigned int nIn, int nHashType=SIGHASH_ALL); -// Given two sets of signatures for scriptPubKey, possibly with OP_0 placeholders, -// combine them intelligently and return the result. +/** + * Given two sets of signatures for scriptPubKey, possibly with OP_0 placeholders, + * combine them intelligently and return the result. + */ CScript CombineSignatures(const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn, const CScript& scriptSig1, const CScript& scriptSig2); #endif // BITCOIN_SCRIPT_SIGN_H diff --git a/src/script/standard.cpp b/src/script/standard.cpp index e238ecedb00..ab6e6cde0de 100644 --- a/src/script/standard.cpp +++ b/src/script/standard.cpp @@ -34,9 +34,9 @@ const char* GetTxnOutputType(txnouttype t) return NULL; } -// -// Return public keys or hashes from scriptPubKey, for 'standard' transaction types. -// +/** + * Return public keys or hashes from scriptPubKey, for 'standard' transaction types. + */ bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector >& vSolutionsRet) { // Templates diff --git a/src/script/standard.h b/src/script/standard.h index 55a27881aa0..f3dcc75fdc8 100644 --- a/src/script/standard.h +++ b/src/script/standard.h @@ -25,27 +25,31 @@ public: CScriptID(const uint160& in) : uint160(in) {} }; -static const unsigned int MAX_OP_RETURN_RELAY = 40; // bytes +static const unsigned int MAX_OP_RETURN_RELAY = 40; //! bytes 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. +/** + * 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. +/** + * 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_MINIMALDATA | SCRIPT_VERIFY_NULLDUMMY; -// For convenience, standard but not mandatory verify flags. +/** 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 @@ -65,7 +69,8 @@ public: friend bool operator<(const CNoDestination &a, const CNoDestination &b) { return true; } }; -/** A txout script template with a specific destination. It is either: +/** + * A txout script template with a specific destination. It is either: * * CNoDestination: no destination set * * CKeyID: TX_PUBKEYHASH destination * * CScriptID: TX_SCRIPTHASH destination