// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2011 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;
// 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
{
// 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
{
return true;
}
+ bool SetSecret(const CSecret& vchSecret)
+ {
+ 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;
+ return true;
+ }
+
+ CSecret GetSecret() 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");
+ return vchRet;
+ }
+
CPrivKey GetPrivKey() const
{
unsigned int nSize = i2d_ECPrivateKey(pkey, NULL);
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 (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;
+ 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;
+ if (vchSig[0]<27 || vchSig[0]>=31)
+ 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 (ECDSA_SIG_recover_key_GFp(pkey, sig, (unsigned char*)&hash, sizeof(hash), vchSig[0] - 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
return true;
}
- static bool Sign(const CPrivKey& vchPrivKey, uint256 hash, std::vector<unsigned char>& vchSig)
+ // Verify a compact signature
+ bool VerifyCompact(uint256 hash, const std::vector<unsigned char>& vchSig)
{
CKey key;
- if (!key.SetPrivKey(vchPrivKey))
+ if (!key.SetCompactSignature(hash, vchSig))
return false;
- return key.Sign(hash, vchSig);
- }
-
- static bool Verify(const std::vector<unsigned char>& vchPubKey, uint256 hash, const std::vector<unsigned char>& vchSig)
- {
- CKey key;
- if (!key.SetPubKey(vchPubKey))
+ if (GetPubKey() != key.GetPubKey())
return false;
- return key.Verify(hash, vchSig);
+ return true;
}
};
git://git.novaco.in / novacoin.git / blobdiff