diff options
Diffstat (limited to 'src/key.h')
| -rw-r--r-- | src/key.h | 223 |
1 files changed, 131 insertions, 92 deletions
@@ -1,11 +1,10 @@ // Copyright (c) 2009-2010 Satoshi Nakamoto -// Copyright (c) 2009-2012 The Bitcoin developers +// Copyright (c) 2009-2013 The Bitcoin developers // Distributed under the MIT/X11 software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #ifndef BITCOIN_KEY_H #define BITCOIN_KEY_H -#include <stdexcept> #include <vector> #include "allocators.h" @@ -13,23 +12,6 @@ #include "uint256.h" #include "hash.h" -#include <openssl/ec.h> // for EC_KEY definition - -// secp160k1 -// const unsigned int PRIVATE_KEY_SIZE = 192; -// const unsigned int PUBLIC_KEY_SIZE = 41; -// const unsigned int SIGNATURE_SIZE = 48; -// -// secp192k1 -// const unsigned int PRIVATE_KEY_SIZE = 222; -// const unsigned int PUBLIC_KEY_SIZE = 49; -// const unsigned int SIGNATURE_SIZE = 57; -// -// secp224k1 -// const unsigned int PRIVATE_KEY_SIZE = 250; -// const unsigned int PUBLIC_KEY_SIZE = 57; -// const unsigned int SIGNATURE_SIZE = 66; -// // secp256k1: // const unsigned int PRIVATE_KEY_SIZE = 279; // const unsigned int PUBLIC_KEY_SIZE = 65; @@ -38,12 +20,6 @@ // see www.keylength.com // script supports up to 75 for single byte push -class key_error : public std::runtime_error -{ -public: - explicit key_error(const std::string& str) : std::runtime_error(str) {} -}; - /** A reference to a CKey: the Hash160 of its serialized public key */ class CKeyID : public uint160 { @@ -63,8 +39,11 @@ public: /** An encapsulated public key. */ class CPubKey { private: + // Just store the serialized data. + // Its length can very cheaply be computed from the first byte. unsigned char vch[65]; + // Compute the length of a pubkey with a given first byte. unsigned int static GetLen(unsigned char chHeader) { if (chHeader == 2 || chHeader == 3) return 33; @@ -73,146 +52,206 @@ private: return 0; } - unsigned char *begin() { - return vch; + // Set this key data to be invalid + void Invalidate() { + vch[0] = 0xFF; } - friend class CKey; - public: - CPubKey() { vch[0] = 0xFF; } - - CPubKey(const std::vector<unsigned char> &vchPubKeyIn) { - int len = vchPubKeyIn.empty() ? 0 : GetLen(vchPubKeyIn[0]); - if (len) { - memcpy(vch, &vchPubKeyIn[0], len); - } else { - vch[0] = 0xFF; - } + // Construct an invalid public key. + CPubKey() { + Invalidate(); } - unsigned int size() const { - return GetLen(vch[0]); + // Initialize a public key using begin/end iterators to byte data. + template<typename T> + void Set(const T pbegin, const T pend) { + int len = pend == pbegin ? 0 : GetLen(pbegin[0]); + if (len && len == (pend-pbegin)) + memcpy(vch, (unsigned char*)&pbegin[0], len); + else + Invalidate(); } - const unsigned char *begin() const { - return vch; + // Construct a public key using begin/end iterators to byte data. + template<typename T> + CPubKey(const T pbegin, const T pend) { + Set(pbegin, pend); } - const unsigned char *end() const { - return vch+size(); + // Construct a public key from a byte vector. + CPubKey(const std::vector<unsigned char> &vch) { + Set(vch.begin(), vch.end()); } - friend bool operator==(const CPubKey &a, const CPubKey &b) { return memcmp(a.vch, b.vch, a.size()) == 0; } - friend bool operator!=(const CPubKey &a, const CPubKey &b) { return memcmp(a.vch, b.vch, a.size()) != 0; } + // Simply read-only vector-like interface to the pubkey data. + unsigned int size() const { return GetLen(vch[0]); } + const unsigned char *begin() const { return vch; } + const unsigned char *end() const { return vch+size(); } + const unsigned char &operator[](unsigned int pos) const { return vch[pos]; } + + // Comparator implementation. + friend bool operator==(const CPubKey &a, const CPubKey &b) { + return a.vch[0] == b.vch[0] && + memcmp(a.vch, b.vch, a.size()) == 0; + } + friend bool operator!=(const CPubKey &a, const CPubKey &b) { + return !(a == b); + } friend bool operator<(const CPubKey &a, const CPubKey &b) { return a.vch[0] < b.vch[0] || - (a.vch[0] == b.vch[0] && memcmp(a.vch+1, b.vch+1, a.size() - 1) < 0); + (a.vch[0] == b.vch[0] && memcmp(a.vch, b.vch, a.size()) < 0); } + // Implement serialization, as if this was a byte vector. unsigned int GetSerializeSize(int nType, int nVersion) const { return size() + 1; } - template<typename Stream> void Serialize(Stream &s, int nType, int nVersion) const { unsigned int len = size(); ::Serialize(s, VARINT(len), nType, nVersion); s.write((char*)vch, len); } - template<typename Stream> void Unserialize(Stream &s, int nType, int nVersion) { unsigned int len; ::Unserialize(s, VARINT(len), nType, nVersion); if (len <= 65) { s.read((char*)vch, len); } else { - // invalid pubkey - vch[0] = 0xFF; + // invalid pubkey, skip available data char dummy; while (len--) s.read(&dummy, 1); + Invalidate(); } } + // Get the KeyID of this public key (hash of its serialization) CKeyID GetID() const { return CKeyID(Hash160(vch, vch+size())); } + // Get the 256-bit hash of this public key. uint256 GetHash() const { return Hash(vch, vch+size()); } + // just check syntactic correctness. bool IsValid() const { return size() > 0; } + // fully validate whether this is a valid public key (more expensive than IsValid()) + bool IsFullyValid() const; + + // Check whether this is a compressed public key. bool IsCompressed() const { return size() == 33; } - std::vector<unsigned char> Raw() const { - return std::vector<unsigned char>(vch, vch+size()); - } + // Verify a DER signature (~72 bytes). + // If this public key is not fully valid, the return value will be false. + bool Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) const; + + // Verify a compact signature (~65 bytes). + // See CKey::SignCompact. + bool VerifyCompact(const uint256 &hash, const std::vector<unsigned char>& vchSig) const; + + // Recover a public key from a compact signature. + bool RecoverCompact(const uint256 &hash, const std::vector<unsigned char>& vchSig); + + // Turn this public key into an uncompressed public key. + bool Decompress(); }; // secure_allocator is defined in allocators.h // CPrivKey is a serialized private key, with all parameters included (279 bytes) typedef std::vector<unsigned char, secure_allocator<unsigned char> > CPrivKey; -// CSecret is a serialization of just the secret parameter (32 bytes) -typedef std::vector<unsigned char, secure_allocator<unsigned char> > CSecret; -/** An encapsulated OpenSSL Elliptic Curve key (public and/or private) */ -class CKey -{ -protected: - EC_KEY* pkey; - bool fSet; - bool fCompressedPubKey; +/** An encapsulated private key. */ +class CKey { +private: + // Whether this private key is valid. We check for correctness when modifying the key + // data, so fValid should always correspond to the actual state. + bool fValid; + // Whether the public key corresponding to this private key is (to be) compressed. + bool fCompressed; + + // The actual byte data + unsigned char vch[32]; + + // Check whether the 32-byte array pointed to be vch is valid keydata. + bool static Check(const unsigned char *vch); public: - void SetCompressedPubKey(bool fCompressed = true); - void Reset(); + // Construct an invalid private key. + CKey() : fValid(false) { + LockObject(vch); + } - CKey(); - CKey(const CKey& b); + // Copy constructor. This is necessary because of memlocking. + CKey(const CKey &secret) : fValid(secret.fValid), fCompressed(secret.fCompressed) { + LockObject(vch); + memcpy(vch, secret.vch, sizeof(vch)); + } - CKey& operator=(const CKey& b); + // Destructor (again necessary because of memlocking). + ~CKey() { + UnlockObject(vch); + } - ~CKey(); + // Initialize using begin and end iterators to byte data. + template<typename T> + void Set(const T pbegin, const T pend, bool fCompressedIn) { + if (pend - pbegin != 32) { + fValid = false; + return; + } + if (Check(&pbegin[0])) { + memcpy(vch, (unsigned char*)&pbegin[0], 32); + fValid = true; + fCompressed = fCompressedIn; + } else { + fValid = false; + } + } + + // Simple read-only vector-like interface. + unsigned int size() const { return (fValid ? 32 : 0); } + const unsigned char *begin() const { return vch; } + const unsigned char *end() const { return vch + size(); } + + // Check whether this private key is valid. + bool IsValid() const { return fValid; } - bool IsNull() const; - bool IsCompressed() const; + // Check whether the public key corresponding to this private key is (to be) compressed. + bool IsCompressed() const { return fCompressed; } + // Initialize from a CPrivKey (serialized OpenSSL private key data). + bool SetPrivKey(const CPrivKey &vchPrivKey, bool fCompressed); + + // Generate a new private key using a cryptographic PRNG. void MakeNewKey(bool fCompressed); - bool SetPrivKey(const CPrivKey& vchPrivKey); - bool SetSecret(const CSecret& vchSecret, bool fCompressed = false); - CSecret GetSecret(bool &fCompressed) const; + + // Convert the private key to a CPrivKey (serialized OpenSSL private key data). + // This is expensive. CPrivKey GetPrivKey() const; - bool SetPubKey(const CPubKey& vchPubKey); + + // Compute the public key from a private key. + // This is expensive. CPubKey GetPubKey() const; - bool Sign(uint256 hash, std::vector<unsigned char>& vchSig); + // Create a DER-serialized signature. + bool Sign(const uint256 &hash, std::vector<unsigned char>& vchSig) const; - // create a compact signature (65 bytes), which allows reconstructing the used public key + // Create a compact signature (65 bytes), which allows reconstructing the used public key. // The format is one header byte, followed by two times 32 bytes for the serialized r and s values. // The header byte: 0x1B = first key with even y, 0x1C = first key with odd y, - // 0x1D = second key with even y, 0x1E = second key with odd y - bool SignCompact(uint256 hash, std::vector<unsigned char>& vchSig); - - // reconstruct public key from a compact signature - // This is only slightly more CPU intensive than just verifying it. - // If this function succeeds, the recovered public key is guaranteed to be valid - // (the signature is a valid signature of the given data for that key) - bool SetCompactSignature(uint256 hash, const std::vector<unsigned char>& vchSig); - - bool Verify(uint256 hash, const std::vector<unsigned char>& vchSig); - - // Verify a compact signature - bool VerifyCompact(uint256 hash, const std::vector<unsigned char>& vchSig); - - bool IsValid(); + // 0x1D = second key with even y, 0x1E = second key with odd y, + // add 0x04 for compressed keys. + bool SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig) const; }; #endif |