325 lines
9.9 KiB
C++
325 lines
9.9 KiB
C++
// Copyright (c) 2009-2010 Satoshi Nakamoto
|
|
// Copyright (c) 2009-2012 The Bitcoin developers
|
|
// Distributed under the MIT/X11 software license, see the accompanying
|
|
// file license.txt or http://www.opensource.org/licenses/mit-license.php.
|
|
#ifndef BITCOIN_KEY_H
|
|
#define BITCOIN_KEY_H
|
|
|
|
#include <stdexcept>
|
|
#include <vector>
|
|
|
|
#include <openssl/ec.h>
|
|
#include <openssl/ecdsa.h>
|
|
#include <openssl/obj_mac.h>
|
|
|
|
#include "serialize.h"
|
|
#include "uint256.h"
|
|
|
|
// 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;
|
|
// const unsigned int SIGNATURE_SIZE = 72;
|
|
//
|
|
// see www.keylength.com
|
|
// script supports up to 75 for single byte push
|
|
|
|
int extern EC_KEY_regenerate_key(EC_KEY *eckey, BIGNUM *priv_key);
|
|
int extern ECDSA_SIG_recover_key_GFp(EC_KEY *eckey, ECDSA_SIG *ecsig, const unsigned char *msg, int msglen, int recid, int check);
|
|
|
|
class key_error : public std::runtime_error
|
|
{
|
|
public:
|
|
explicit key_error(const std::string& str) : std::runtime_error(str) {}
|
|
};
|
|
|
|
|
|
// secure_allocator is defined in serialize.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;
|
|
|
|
class CKey
|
|
{
|
|
protected:
|
|
EC_KEY* pkey;
|
|
bool fSet;
|
|
bool fCompressedPubKey;
|
|
|
|
void SetCompressedPubKey()
|
|
{
|
|
EC_KEY_set_conv_form(pkey, POINT_CONVERSION_COMPRESSED);
|
|
fCompressedPubKey = true;
|
|
}
|
|
|
|
public:
|
|
|
|
void Reset()
|
|
{
|
|
fCompressedPubKey = false;
|
|
pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
|
|
if (pkey == NULL)
|
|
throw key_error("CKey::CKey() : EC_KEY_new_by_curve_name failed");
|
|
fSet = false;
|
|
}
|
|
|
|
CKey()
|
|
{
|
|
Reset();
|
|
}
|
|
|
|
CKey(const CKey& b)
|
|
{
|
|
pkey = EC_KEY_dup(b.pkey);
|
|
if (pkey == NULL)
|
|
throw key_error("CKey::CKey(const CKey&) : EC_KEY_dup failed");
|
|
fSet = b.fSet;
|
|
}
|
|
|
|
CKey& operator=(const CKey& b)
|
|
{
|
|
if (!EC_KEY_copy(pkey, b.pkey))
|
|
throw key_error("CKey::operator=(const CKey&) : EC_KEY_copy failed");
|
|
fSet = b.fSet;
|
|
return (*this);
|
|
}
|
|
|
|
~CKey()
|
|
{
|
|
EC_KEY_free(pkey);
|
|
}
|
|
|
|
bool IsNull() const
|
|
{
|
|
return !fSet;
|
|
}
|
|
|
|
bool IsCompressed() const
|
|
{
|
|
return fCompressedPubKey;
|
|
}
|
|
|
|
void MakeNewKey(bool fCompressed = true)
|
|
{
|
|
if (!EC_KEY_generate_key(pkey))
|
|
throw key_error("CKey::MakeNewKey() : EC_KEY_generate_key failed");
|
|
if (fCompressed)
|
|
SetCompressedPubKey();
|
|
fSet = true;
|
|
}
|
|
|
|
bool SetPrivKey(const CPrivKey& vchPrivKey)
|
|
{
|
|
const unsigned char* pbegin = &vchPrivKey[0];
|
|
if (!d2i_ECPrivateKey(&pkey, &pbegin, vchPrivKey.size()))
|
|
return false;
|
|
fSet = true;
|
|
return true;
|
|
}
|
|
|
|
bool SetSecret(const CSecret& vchSecret, bool fCompressed = false)
|
|
{
|
|
EC_KEY_free(pkey);
|
|
pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
|
|
if (pkey == NULL)
|
|
throw key_error("CKey::SetSecret() : EC_KEY_new_by_curve_name failed");
|
|
if (vchSecret.size() != 32)
|
|
throw key_error("CKey::SetSecret() : secret must be 32 bytes");
|
|
BIGNUM *bn = BN_bin2bn(&vchSecret[0],32,BN_new());
|
|
if (bn == NULL)
|
|
throw key_error("CKey::SetSecret() : BN_bin2bn failed");
|
|
if (!EC_KEY_regenerate_key(pkey,bn))
|
|
throw key_error("CKey::SetSecret() : EC_KEY_regenerate_key failed");
|
|
BN_clear_free(bn);
|
|
fSet = true;
|
|
if (fCompressed || fCompressedPubKey)
|
|
SetCompressedPubKey();
|
|
return true;
|
|
}
|
|
|
|
CSecret GetSecret(bool &fCompressed) const
|
|
{
|
|
CSecret vchRet;
|
|
vchRet.resize(32);
|
|
const BIGNUM *bn = EC_KEY_get0_private_key(pkey);
|
|
int nBytes = BN_num_bytes(bn);
|
|
if (bn == NULL)
|
|
throw key_error("CKey::GetSecret() : EC_KEY_get0_private_key failed");
|
|
int n=BN_bn2bin(bn,&vchRet[32 - nBytes]);
|
|
if (n != nBytes)
|
|
throw key_error("CKey::GetSecret(): BN_bn2bin failed");
|
|
fCompressed = fCompressedPubKey;
|
|
return vchRet;
|
|
}
|
|
|
|
CPrivKey GetPrivKey() const
|
|
{
|
|
unsigned int nSize = i2d_ECPrivateKey(pkey, NULL);
|
|
if (!nSize)
|
|
throw key_error("CKey::GetPrivKey() : i2d_ECPrivateKey failed");
|
|
CPrivKey vchPrivKey(nSize, 0);
|
|
unsigned char* pbegin = &vchPrivKey[0];
|
|
if (i2d_ECPrivateKey(pkey, &pbegin) != nSize)
|
|
throw key_error("CKey::GetPrivKey() : i2d_ECPrivateKey returned unexpected size");
|
|
return vchPrivKey;
|
|
}
|
|
|
|
bool SetPubKey(const std::vector<unsigned char>& vchPubKey)
|
|
{
|
|
const unsigned char* pbegin = &vchPubKey[0];
|
|
if (!o2i_ECPublicKey(&pkey, &pbegin, vchPubKey.size()))
|
|
return false;
|
|
fSet = true;
|
|
if (vchPubKey.size() == 33)
|
|
SetCompressedPubKey();
|
|
return true;
|
|
}
|
|
|
|
std::vector<unsigned char> GetPubKey() const
|
|
{
|
|
unsigned int nSize = i2o_ECPublicKey(pkey, NULL);
|
|
if (!nSize)
|
|
throw key_error("CKey::GetPubKey() : i2o_ECPublicKey failed");
|
|
std::vector<unsigned char> vchPubKey(nSize, 0);
|
|
unsigned char* pbegin = &vchPubKey[0];
|
|
if (i2o_ECPublicKey(pkey, &pbegin) != nSize)
|
|
throw key_error("CKey::GetPubKey() : i2o_ECPublicKey returned unexpected size");
|
|
return vchPubKey;
|
|
}
|
|
|
|
bool Sign(uint256 hash, std::vector<unsigned char>& vchSig)
|
|
{
|
|
unsigned int nSize = ECDSA_size(pkey);
|
|
vchSig.resize(nSize); // Make sure it is big enough
|
|
if (!ECDSA_sign(0, (unsigned char*)&hash, sizeof(hash), &vchSig[0], &nSize, pkey))
|
|
{
|
|
vchSig.clear();
|
|
return false;
|
|
}
|
|
vchSig.resize(nSize); // Shrink to fit actual size
|
|
return true;
|
|
}
|
|
|
|
// 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)
|
|
{
|
|
bool fOk = false;
|
|
ECDSA_SIG *sig = ECDSA_do_sign((unsigned char*)&hash, sizeof(hash), pkey);
|
|
if (sig==NULL)
|
|
return false;
|
|
vchSig.clear();
|
|
vchSig.resize(65,0);
|
|
int nBitsR = BN_num_bits(sig->r);
|
|
int nBitsS = BN_num_bits(sig->s);
|
|
if (nBitsR <= 256 && nBitsS <= 256)
|
|
{
|
|
int nRecId = -1;
|
|
for (int i=0; i<4; i++)
|
|
{
|
|
CKey keyRec;
|
|
keyRec.fSet = true;
|
|
if (fCompressedPubKey)
|
|
keyRec.SetCompressedPubKey();
|
|
if (ECDSA_SIG_recover_key_GFp(keyRec.pkey, sig, (unsigned char*)&hash, sizeof(hash), i, 1) == 1)
|
|
if (keyRec.GetPubKey() == this->GetPubKey())
|
|
{
|
|
nRecId = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (nRecId == -1)
|
|
throw key_error("CKey::SignCompact() : unable to construct recoverable key");
|
|
|
|
vchSig[0] = nRecId+27+(fCompressedPubKey ? 4 : 0);
|
|
BN_bn2bin(sig->r,&vchSig[33-(nBitsR+7)/8]);
|
|
BN_bn2bin(sig->s,&vchSig[65-(nBitsS+7)/8]);
|
|
fOk = true;
|
|
}
|
|
ECDSA_SIG_free(sig);
|
|
return fOk;
|
|
}
|
|
|
|
// 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)
|
|
{
|
|
if (vchSig.size() != 65)
|
|
return false;
|
|
int nV = vchSig[0];
|
|
if (nV<27 || nV>=35)
|
|
return false;
|
|
ECDSA_SIG *sig = ECDSA_SIG_new();
|
|
BN_bin2bn(&vchSig[1],32,sig->r);
|
|
BN_bin2bn(&vchSig[33],32,sig->s);
|
|
|
|
EC_KEY_free(pkey);
|
|
pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
|
|
if (nV >= 31)
|
|
{
|
|
SetCompressedPubKey();
|
|
nV -= 4;
|
|
}
|
|
if (ECDSA_SIG_recover_key_GFp(pkey, sig, (unsigned char*)&hash, sizeof(hash), nV - 27, 0) == 1)
|
|
{
|
|
fSet = true;
|
|
ECDSA_SIG_free(sig);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool Verify(uint256 hash, const std::vector<unsigned char>& vchSig)
|
|
{
|
|
// -1 = error, 0 = bad sig, 1 = good
|
|
if (ECDSA_verify(0, (unsigned char*)&hash, sizeof(hash), &vchSig[0], vchSig.size(), pkey) != 1)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
// Verify a compact signature
|
|
bool VerifyCompact(uint256 hash, const std::vector<unsigned char>& vchSig)
|
|
{
|
|
CKey key;
|
|
if (!key.SetCompactSignature(hash, vchSig))
|
|
return false;
|
|
if (GetPubKey() != key.GetPubKey())
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
bool IsValid()
|
|
{
|
|
if (!fSet)
|
|
return false;
|
|
|
|
bool fCompr;
|
|
CSecret secret = GetSecret(fCompr);
|
|
CKey key2;
|
|
key2.SetSecret(secret, fCompr);
|
|
return GetPubKey() == key2.GetPubKey();
|
|
}
|
|
};
|
|
|
|
#endif
|