lbrycrd/src/key.h
Cory Fields 066e2a1403 script: move CScriptID to standard.h and add a ctor for creating them from CScripts
This allows for a reversal of the current behavior.

This:
CScript foo;
CScriptID bar(foo.GetID());

Becomes:
CScript foo;
CScriptID bar(foo);

This way, CScript is no longer dependent on CScriptID or Hash();
2014-10-17 13:44:14 -04:00

331 lines
10 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// 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 "allocators.h"
#include "hash.h"
#include "serialize.h"
#include "uint256.h"
#include <stdexcept>
#include <vector>
// secp256k1:
// const unsigned int PRIVATE_KEY_SIZE = 279;
// const unsigned int PUBLIC_KEY_SIZE = 65;
// const unsigned int SIGNATURE_SIZE = 72;
//
// see www.keylength.com
// script supports up to 75 for single byte push
/** A reference to a CKey: the Hash160 of its serialized public key */
class CKeyID : public uint160
{
public:
CKeyID() : uint160(0) {}
CKeyID(const uint160& in) : uint160(in) {}
};
/** 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;
if (chHeader == 4 || chHeader == 6 || chHeader == 7)
return 65;
return 0;
}
// Set this key data to be invalid
void Invalidate()
{
vch[0] = 0xFF;
}
public:
// Construct an invalid public key.
CPubKey()
{
Invalidate();
}
// 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();
}
// Construct a public key using begin/end iterators to byte data.
template <typename T>
CPubKey(const T pbegin, const T pend)
{
Set(pbegin, pend);
}
// Construct a public key from a byte vector.
CPubKey(const std::vector<unsigned char>& vch)
{
Set(vch.begin(), vch.end());
}
// Simple 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, 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();
::WriteCompactSize(s, len);
s.write((char*)vch, len);
}
template <typename Stream>
void Unserialize(Stream& s, int nType, int nVersion)
{
unsigned int len = ::ReadCompactSize(s);
if (len <= 65) {
s.read((char*)vch, len);
} else {
// 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());
}
// Check syntactic correctness.
//
// Note that this is consensus critical as CheckSig() calls it!
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;
}
// 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;
// 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();
// Derive BIP32 child pubkey.
bool Derive(CPubKey& pubkeyChild, unsigned char ccChild[32], unsigned int nChild, const unsigned char cc[32]) const;
};
// 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;
/** 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:
// Construct an invalid private key.
CKey() : fValid(false), fCompressed(false)
{
LockObject(vch);
}
// 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));
}
// Destructor (again necessary because of memlocking).
~CKey()
{
UnlockObject(vch);
}
friend bool operator==(const CKey& a, const CKey& b)
{
return a.fCompressed == b.fCompressed && a.size() == b.size() &&
memcmp(&a.vch[0], &b.vch[0], a.size()) == 0;
}
// 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; }
// 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);
// Convert the private key to a CPrivKey (serialized OpenSSL private key data).
// This is expensive.
CPrivKey GetPrivKey() const;
// Compute the public key from a private key.
// This is expensive.
CPubKey GetPubKey() const;
// Create a DER-serialized signature.
bool Sign(const uint256& hash, std::vector<unsigned char>& vchSig, bool lowS = true) const;
// 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,
// add 0x04 for compressed keys.
bool SignCompact(const uint256& hash, std::vector<unsigned char>& vchSig) const;
// Derive BIP32 child key.
bool Derive(CKey& keyChild, unsigned char ccChild[32], unsigned int nChild, const unsigned char cc[32]) const;
// Load private key and check that public key matches.
bool Load(CPrivKey& privkey, CPubKey& vchPubKey, bool fSkipCheck);
// Check whether an element of a signature (r or s) is valid.
static bool CheckSignatureElement(const unsigned char* vch, int len, bool half);
};
struct CExtPubKey {
unsigned char nDepth;
unsigned char vchFingerprint[4];
unsigned int nChild;
unsigned char vchChainCode[32];
CPubKey pubkey;
friend bool operator==(const CExtPubKey& a, const CExtPubKey& b)
{
return a.nDepth == b.nDepth && memcmp(&a.vchFingerprint[0], &b.vchFingerprint[0], 4) == 0 && a.nChild == b.nChild &&
memcmp(&a.vchChainCode[0], &b.vchChainCode[0], 32) == 0 && a.pubkey == b.pubkey;
}
void Encode(unsigned char code[74]) const;
void Decode(const unsigned char code[74]);
bool Derive(CExtPubKey& out, unsigned int nChild) const;
};
struct CExtKey {
unsigned char nDepth;
unsigned char vchFingerprint[4];
unsigned int nChild;
unsigned char vchChainCode[32];
CKey key;
friend bool operator==(const CExtKey& a, const CExtKey& b)
{
return a.nDepth == b.nDepth && memcmp(&a.vchFingerprint[0], &b.vchFingerprint[0], 4) == 0 && a.nChild == b.nChild &&
memcmp(&a.vchChainCode[0], &b.vchChainCode[0], 32) == 0 && a.key == b.key;
}
void Encode(unsigned char code[74]) const;
void Decode(const unsigned char code[74]);
bool Derive(CExtKey& out, unsigned int nChild) const;
CExtPubKey Neuter() const;
void SetMaster(const unsigned char* seed, unsigned int nSeedLen);
};
/** Check that required EC support is available at runtime */
bool ECC_InitSanityCheck(void);
#endif // BITCOIN_KEY_H