lbrycrd/src/pubkey.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_PUBKEY_H
#define BITCOIN_PUBKEY_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() {}
CKeyID(const uint160& in) : uint160(in) {}
};
typedef uint256 ChainCode;
/** 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;
/**
* Check whether a signature is normalized (lower-S).
*/
static bool CheckLowS(const std::vector<unsigned char>& vchSig);
//! 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, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc) const;
};
struct CExtPubKey {
unsigned char nDepth;
unsigned char vchFingerprint[4];
unsigned int nChild;
ChainCode chaincode;
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 &&
a.chaincode == b.chaincode && 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;
};
/** Users of this module must hold an ECCVerifyHandle. The constructor and
* destructor of these are not allowed to run in parallel, though. */
class ECCVerifyHandle
{
static int refcount;
public:
ECCVerifyHandle();
~ECCVerifyHandle();
};
#endif // BITCOIN_PUBKEY_H