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kevacoin/src/key.cpp

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// Copyright (c) 2009-2014 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "key.h"
#include "crypto/sha2.h"
#include "random.h"
#ifdef USE_SECP256K1
#include <secp256k1.h>
#else
#include <openssl/bn.h>
#include <openssl/ecdsa.h>
#include <openssl/obj_mac.h>
#endif
// anonymous namespace with local implementation code (OpenSSL interaction)
namespace {
#ifdef USE_SECP256K1
#include <secp256k1.h>
class CSecp256k1Init {
public:
CSecp256k1Init() {
secp256k1_start();
}
~CSecp256k1Init() {
secp256k1_stop();
}
};
static CSecp256k1Init instance_of_csecp256k1;
#else
// Generate a private key from just the secret parameter
int EC_KEY_regenerate_key(EC_KEY *eckey, BIGNUM *priv_key)
{
int ok = 0;
BN_CTX *ctx = NULL;
EC_POINT *pub_key = NULL;
if (!eckey) return 0;
const EC_GROUP *group = EC_KEY_get0_group(eckey);
if ((ctx = BN_CTX_new()) == NULL)
goto err;
pub_key = EC_POINT_new(group);
if (pub_key == NULL)
goto err;
if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx))
goto err;
EC_KEY_set_private_key(eckey,priv_key);
EC_KEY_set_public_key(eckey,pub_key);
ok = 1;
err:
if (pub_key)
EC_POINT_free(pub_key);
if (ctx != NULL)
BN_CTX_free(ctx);
return(ok);
}
// Perform ECDSA key recovery (see SEC1 4.1.6) for curves over (mod p)-fields
// recid selects which key is recovered
// if check is non-zero, additional checks are performed
int ECDSA_SIG_recover_key_GFp(EC_KEY *eckey, ECDSA_SIG *ecsig, const unsigned char *msg, int msglen, int recid, int check)
{
if (!eckey) return 0;
int ret = 0;
BN_CTX *ctx = NULL;
BIGNUM *x = NULL;
BIGNUM *e = NULL;
BIGNUM *order = NULL;
BIGNUM *sor = NULL;
BIGNUM *eor = NULL;
BIGNUM *field = NULL;
EC_POINT *R = NULL;
EC_POINT *O = NULL;
EC_POINT *Q = NULL;
BIGNUM *rr = NULL;
BIGNUM *zero = NULL;
int n = 0;
int i = recid / 2;
const EC_GROUP *group = EC_KEY_get0_group(eckey);
if ((ctx = BN_CTX_new()) == NULL) { ret = -1; goto err; }
BN_CTX_start(ctx);
order = BN_CTX_get(ctx);
if (!EC_GROUP_get_order(group, order, ctx)) { ret = -2; goto err; }
x = BN_CTX_get(ctx);
if (!BN_copy(x, order)) { ret=-1; goto err; }
if (!BN_mul_word(x, i)) { ret=-1; goto err; }
if (!BN_add(x, x, ecsig->r)) { ret=-1; goto err; }
field = BN_CTX_get(ctx);
if (!EC_GROUP_get_curve_GFp(group, field, NULL, NULL, ctx)) { ret=-2; goto err; }
if (BN_cmp(x, field) >= 0) { ret=0; goto err; }
if ((R = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
if (!EC_POINT_set_compressed_coordinates_GFp(group, R, x, recid % 2, ctx)) { ret=0; goto err; }
if (check)
{
if ((O = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
if (!EC_POINT_mul(group, O, NULL, R, order, ctx)) { ret=-2; goto err; }
if (!EC_POINT_is_at_infinity(group, O)) { ret = 0; goto err; }
}
if ((Q = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
n = EC_GROUP_get_degree(group);
e = BN_CTX_get(ctx);
if (!BN_bin2bn(msg, msglen, e)) { ret=-1; goto err; }
if (8*msglen > n) BN_rshift(e, e, 8-(n & 7));
zero = BN_CTX_get(ctx);
if (!BN_zero(zero)) { ret=-1; goto err; }
if (!BN_mod_sub(e, zero, e, order, ctx)) { ret=-1; goto err; }
rr = BN_CTX_get(ctx);
if (!BN_mod_inverse(rr, ecsig->r, order, ctx)) { ret=-1; goto err; }
sor = BN_CTX_get(ctx);
if (!BN_mod_mul(sor, ecsig->s, rr, order, ctx)) { ret=-1; goto err; }
eor = BN_CTX_get(ctx);
if (!BN_mod_mul(eor, e, rr, order, ctx)) { ret=-1; goto err; }
if (!EC_POINT_mul(group, Q, eor, R, sor, ctx)) { ret=-2; goto err; }
if (!EC_KEY_set_public_key(eckey, Q)) { ret=-2; goto err; }
ret = 1;
err:
if (ctx) {
BN_CTX_end(ctx);
BN_CTX_free(ctx);
}
if (R != NULL) EC_POINT_free(R);
if (O != NULL) EC_POINT_free(O);
if (Q != NULL) EC_POINT_free(Q);
return ret;
}
// RAII Wrapper around OpenSSL's EC_KEY
class CECKey {
private:
EC_KEY *pkey;
public:
CECKey() {
pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
assert(pkey != NULL);
}
~CECKey() {
EC_KEY_free(pkey);
}
void GetSecretBytes(unsigned char vch[32]) const {
const BIGNUM *bn = EC_KEY_get0_private_key(pkey);
assert(bn);
int nBytes = BN_num_bytes(bn);
int n=BN_bn2bin(bn,&vch[32 - nBytes]);
assert(n == nBytes);
memset(vch, 0, 32 - nBytes);
}
void SetSecretBytes(const unsigned char vch[32]) {
bool ret;
BIGNUM bn;
BN_init(&bn);
ret = BN_bin2bn(vch, 32, &bn) != NULL;
assert(ret);
ret = EC_KEY_regenerate_key(pkey, &bn) != 0;
assert(ret);
BN_clear_free(&bn);
}
void GetPrivKey(CPrivKey &privkey, bool fCompressed) {
EC_KEY_set_conv_form(pkey, fCompressed ? POINT_CONVERSION_COMPRESSED : POINT_CONVERSION_UNCOMPRESSED);
int nSize = i2d_ECPrivateKey(pkey, NULL);
assert(nSize);
privkey.resize(nSize);
unsigned char* pbegin = &privkey[0];
int nSize2 = i2d_ECPrivateKey(pkey, &pbegin);
assert(nSize == nSize2);
}
bool SetPrivKey(const CPrivKey &privkey, bool fSkipCheck=false) {
const unsigned char* pbegin = &privkey[0];
if (d2i_ECPrivateKey(&pkey, &pbegin, privkey.size())) {
if(fSkipCheck)
return true;
// d2i_ECPrivateKey returns true if parsing succeeds.
// This doesn't necessarily mean the key is valid.
if (EC_KEY_check_key(pkey))
return true;
}
return false;
}
void GetPubKey(CPubKey &pubkey, bool fCompressed) {
EC_KEY_set_conv_form(pkey, fCompressed ? POINT_CONVERSION_COMPRESSED : POINT_CONVERSION_UNCOMPRESSED);
int nSize = i2o_ECPublicKey(pkey, NULL);
assert(nSize);
assert(nSize <= 65);
unsigned char c[65];
unsigned char *pbegin = c;
int nSize2 = i2o_ECPublicKey(pkey, &pbegin);
assert(nSize == nSize2);
pubkey.Set(&c[0], &c[nSize]);
}
bool SetPubKey(const CPubKey &pubkey) {
const unsigned char* pbegin = pubkey.begin();
return o2i_ECPublicKey(&pkey, &pbegin, pubkey.size()) != NULL;
}
bool Sign(const uint256 &hash, std::vector<unsigned char>& vchSig, bool lowS) {
vchSig.clear();
ECDSA_SIG *sig = ECDSA_do_sign((unsigned char*)&hash, sizeof(hash), pkey);
if (sig == NULL)
return false;
BN_CTX *ctx = BN_CTX_new();
BN_CTX_start(ctx);
const EC_GROUP *group = EC_KEY_get0_group(pkey);
BIGNUM *order = BN_CTX_get(ctx);
BIGNUM *halforder = BN_CTX_get(ctx);
EC_GROUP_get_order(group, order, ctx);
BN_rshift1(halforder, order);
if (lowS && BN_cmp(sig->s, halforder) > 0) {
// enforce low S values, by negating the value (modulo the order) if above order/2.
BN_sub(sig->s, order, sig->s);
}
BN_CTX_end(ctx);
BN_CTX_free(ctx);
unsigned int nSize = ECDSA_size(pkey);
vchSig.resize(nSize); // Make sure it is big enough
unsigned char *pos = &vchSig[0];
nSize = i2d_ECDSA_SIG(sig, &pos);
ECDSA_SIG_free(sig);
vchSig.resize(nSize); // Shrink to fit actual size
return true;
}
bool Verify(const 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;
}
bool SignCompact(const uint256 &hash, unsigned char *p64, int &rec) {
bool fOk = false;
ECDSA_SIG *sig = ECDSA_do_sign((unsigned char*)&hash, sizeof(hash), pkey);
if (sig==NULL)
return false;
memset(p64, 0, 64);
int nBitsR = BN_num_bits(sig->r);
int nBitsS = BN_num_bits(sig->s);
if (nBitsR <= 256 && nBitsS <= 256) {
CPubKey pubkey;
GetPubKey(pubkey, true);
for (int i=0; i<4; i++) {
CECKey keyRec;
if (ECDSA_SIG_recover_key_GFp(keyRec.pkey, sig, (unsigned char*)&hash, sizeof(hash), i, 1) == 1) {
CPubKey pubkeyRec;
keyRec.GetPubKey(pubkeyRec, true);
if (pubkeyRec == pubkey) {
rec = i;
fOk = true;
break;
}
}
}
assert(fOk);
BN_bn2bin(sig->r,&p64[32-(nBitsR+7)/8]);
BN_bn2bin(sig->s,&p64[64-(nBitsS+7)/8]);
}
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 Recover(const uint256 &hash, const unsigned char *p64, int rec)
{
if (rec<0 || rec>=3)
return false;
ECDSA_SIG *sig = ECDSA_SIG_new();
BN_bin2bn(&p64[0], 32, sig->r);
BN_bin2bn(&p64[32], 32, sig->s);
bool ret = ECDSA_SIG_recover_key_GFp(pkey, sig, (unsigned char*)&hash, sizeof(hash), rec, 0) == 1;
ECDSA_SIG_free(sig);
return ret;
}
static bool TweakSecret(unsigned char vchSecretOut[32], const unsigned char vchSecretIn[32], const unsigned char vchTweak[32])
{
bool ret = true;
BN_CTX *ctx = BN_CTX_new();
BN_CTX_start(ctx);
BIGNUM *bnSecret = BN_CTX_get(ctx);
BIGNUM *bnTweak = BN_CTX_get(ctx);
BIGNUM *bnOrder = BN_CTX_get(ctx);
EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp256k1);
EC_GROUP_get_order(group, bnOrder, ctx); // what a grossly inefficient way to get the (constant) group order...
BN_bin2bn(vchTweak, 32, bnTweak);
if (BN_cmp(bnTweak, bnOrder) >= 0)
ret = false; // extremely unlikely
BN_bin2bn(vchSecretIn, 32, bnSecret);
BN_add(bnSecret, bnSecret, bnTweak);
BN_nnmod(bnSecret, bnSecret, bnOrder, ctx);
if (BN_is_zero(bnSecret))
ret = false; // ridiculously unlikely
int nBits = BN_num_bits(bnSecret);
memset(vchSecretOut, 0, 32);
BN_bn2bin(bnSecret, &vchSecretOut[32-(nBits+7)/8]);
EC_GROUP_free(group);
BN_CTX_end(ctx);
BN_CTX_free(ctx);
return ret;
}
bool TweakPublic(const unsigned char vchTweak[32]) {
bool ret = true;
BN_CTX *ctx = BN_CTX_new();
BN_CTX_start(ctx);
BIGNUM *bnTweak = BN_CTX_get(ctx);
BIGNUM *bnOrder = BN_CTX_get(ctx);
BIGNUM *bnOne = BN_CTX_get(ctx);
const EC_GROUP *group = EC_KEY_get0_group(pkey);
EC_GROUP_get_order(group, bnOrder, ctx); // what a grossly inefficient way to get the (constant) group order...
BN_bin2bn(vchTweak, 32, bnTweak);
if (BN_cmp(bnTweak, bnOrder) >= 0)
ret = false; // extremely unlikely
EC_POINT *point = EC_POINT_dup(EC_KEY_get0_public_key(pkey), group);
BN_one(bnOne);
EC_POINT_mul(group, point, bnTweak, point, bnOne, ctx);
if (EC_POINT_is_at_infinity(group, point))
ret = false; // ridiculously unlikely
EC_KEY_set_public_key(pkey, point);
EC_POINT_free(point);
BN_CTX_end(ctx);
BN_CTX_free(ctx);
return ret;
}
};
#endif
int CompareBigEndian(const unsigned char *c1, size_t c1len, const unsigned char *c2, size_t c2len) {
while (c1len > c2len) {
if (*c1)
return 1;
c1++;
c1len--;
}
while (c2len > c1len) {
if (*c2)
return -1;
c2++;
c2len--;
}
while (c1len > 0) {
if (*c1 > *c2)
return 1;
if (*c2 > *c1)
return -1;
c1++;
c2++;
c1len--;
}
return 0;
}
// Order of secp256k1's generator minus 1.
const unsigned char vchMaxModOrder[32] = {
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,
0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,
0xBF,0xD2,0x5E,0x8C,0xD0,0x36,0x41,0x40
};
// Half of the order of secp256k1's generator minus 1.
const unsigned char vchMaxModHalfOrder[32] = {
0x7F,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0x5D,0x57,0x6E,0x73,0x57,0xA4,0x50,0x1D,
0xDF,0xE9,0x2F,0x46,0x68,0x1B,0x20,0xA0
};
const unsigned char vchZero[1] = {0};
} // anon namespace
bool CKey::Check(const unsigned char *vch) {
return CompareBigEndian(vch, 32, vchZero, 0) > 0 &&
CompareBigEndian(vch, 32, vchMaxModOrder, 32) <= 0;
}
bool CKey::CheckSignatureElement(const unsigned char *vch, int len, bool half) {
return CompareBigEndian(vch, len, vchZero, 0) > 0 &&
CompareBigEndian(vch, len, half ? vchMaxModHalfOrder : vchMaxModOrder, 32) <= 0;
}
void CKey::MakeNewKey(bool fCompressedIn) {
do {
GetRandBytes(vch, sizeof(vch));
} while (!Check(vch));
fValid = true;
fCompressed = fCompressedIn;
}
bool CKey::SetPrivKey(const CPrivKey &privkey, bool fCompressedIn) {
#ifdef USE_SECP256K1
if (!secp256k1_ecdsa_privkey_import((unsigned char*)begin(), &privkey[0], privkey.size()))
return false;
#else
CECKey key;
if (!key.SetPrivKey(privkey))
return false;
key.GetSecretBytes(vch);
#endif
fCompressed = fCompressedIn;
fValid = true;
return true;
}
CPrivKey CKey::GetPrivKey() const {
assert(fValid);
CPrivKey privkey;
#ifdef USE_SECP256K1
privkey.resize(279);
int privkeylen = 279;
int ret = secp256k1_ecdsa_privkey_export(begin(), (unsigned char*)&privkey[0], &privkeylen, fCompressed);
assert(ret);
privkey.resize(privkeylen);
#else
CECKey key;
key.SetSecretBytes(vch);
key.GetPrivKey(privkey, fCompressed);
#endif
return privkey;
}
CPubKey CKey::GetPubKey() const {
assert(fValid);
CPubKey pubkey;
#ifdef USE_SECP256K1
int clen = 65;
int ret = secp256k1_ecdsa_pubkey_create((unsigned char*)pubkey.begin(), &clen, begin(), fCompressed);
assert(ret);
assert(pubkey.IsValid());
assert((int)pubkey.size() == clen);
#else
CECKey key;
key.SetSecretBytes(vch);
key.GetPubKey(pubkey, fCompressed);
#endif
return pubkey;
}
bool CKey::Sign(const uint256 &hash, std::vector<unsigned char>& vchSig, bool lowS) const {
if (!fValid)
return false;
#ifdef USE_SECP256K1
vchSig.resize(72);
int nSigLen = 72;
CKey nonce;
do {
nonce.MakeNewKey(true);
if (secp256k1_ecdsa_sign((const unsigned char*)&hash, 32, (unsigned char*)&vchSig[0], &nSigLen, begin(), nonce.begin()))
break;
} while(true);
vchSig.resize(nSigLen);
return true;
#else
CECKey key;
key.SetSecretBytes(vch);
return key.Sign(hash, vchSig, lowS);
#endif
}
bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig) const {
if (!fValid)
return false;
vchSig.resize(65);
int rec = -1;
#ifdef USE_SECP256K1
CKey nonce;
do {
nonce.MakeNewKey(true);
if (secp256k1_ecdsa_sign_compact((const unsigned char*)&hash, 32, &vchSig[1], begin(), nonce.begin(), &rec))
break;
} while(true);
#else
CECKey key;
key.SetSecretBytes(vch);
if (!key.SignCompact(hash, &vchSig[1], rec))
return false;
#endif
assert(rec != -1);
vchSig[0] = 27 + rec + (fCompressed ? 4 : 0);
return true;
}
bool CKey::Load(CPrivKey &privkey, CPubKey &vchPubKey, bool fSkipCheck=false) {
#ifdef USE_SECP256K1
if (!secp256k1_ecdsa_privkey_import((unsigned char*)begin(), &privkey[0], privkey.size()))
return false;
#else
CECKey key;
if (!key.SetPrivKey(privkey, fSkipCheck))
return false;
key.GetSecretBytes(vch);
#endif
fCompressed = vchPubKey.IsCompressed();
fValid = true;
if (fSkipCheck)
return true;
if (GetPubKey() != vchPubKey)
return false;
return true;
}
bool CPubKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) const {
if (!IsValid())
return false;
#ifdef USE_SECP256K1
if (secp256k1_ecdsa_verify((const unsigned char*)&hash, 32, &vchSig[0], vchSig.size(), begin(), size()) != 1)
return false;
#else
CECKey key;
if (!key.SetPubKey(*this))
return false;
if (!key.Verify(hash, vchSig))
return false;
#endif
return true;
}
bool CPubKey::RecoverCompact(const uint256 &hash, const std::vector<unsigned char>& vchSig) {
if (vchSig.size() != 65)
return false;
int recid = (vchSig[0] - 27) & 3;
bool fComp = ((vchSig[0] - 27) & 4) != 0;
#ifdef USE_SECP256K1
int pubkeylen = 65;
if (!secp256k1_ecdsa_recover_compact((const unsigned char*)&hash, 32, &vchSig[1], (unsigned char*)begin(), &pubkeylen, fComp, recid))
return false;
assert((int)size() == pubkeylen);
#else
CECKey key;
if (!key.Recover(hash, &vchSig[1], recid))
return false;
key.GetPubKey(*this, fComp);
#endif
return true;
}
bool CPubKey::IsFullyValid() const {
if (!IsValid())
return false;
#ifdef USE_SECP256K1
if (!secp256k1_ecdsa_pubkey_verify(begin(), size()))
return false;
#else
CECKey key;
if (!key.SetPubKey(*this))
return false;
#endif
return true;
}
bool CPubKey::Decompress() {
if (!IsValid())
return false;
#ifdef USE_SECP256K1
int clen = size();
int ret = secp256k1_ecdsa_pubkey_decompress((unsigned char*)begin(), &clen);
assert(ret);
assert(clen == (int)size());
#else
CECKey key;
if (!key.SetPubKey(*this))
return false;
key.GetPubKey(*this, false);
#endif
return true;
}
void static BIP32Hash(const unsigned char chainCode[32], unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64]) {
unsigned char num[4];
num[0] = (nChild >> 24) & 0xFF;
num[1] = (nChild >> 16) & 0xFF;
num[2] = (nChild >> 8) & 0xFF;
num[3] = (nChild >> 0) & 0xFF;
CHMAC_SHA512(chainCode, 32).Write(&header, 1)
.Write(data, 32)
.Write(num, 4)
.Finalize(output);
}
bool CKey::Derive(CKey& keyChild, unsigned char ccChild[32], unsigned int nChild, const unsigned char cc[32]) const {
assert(IsValid());
assert(IsCompressed());
unsigned char out[64];
LockObject(out);
if ((nChild >> 31) == 0) {
CPubKey pubkey = GetPubKey();
assert(pubkey.begin() + 33 == pubkey.end());
BIP32Hash(cc, nChild, *pubkey.begin(), pubkey.begin()+1, out);
} else {
assert(begin() + 32 == end());
BIP32Hash(cc, nChild, 0, begin(), out);
}
memcpy(ccChild, out+32, 32);
#ifdef USE_SECP256K1
memcpy((unsigned char*)keyChild.begin(), begin(), 32);
bool ret = secp256k1_ecdsa_privkey_tweak_add((unsigned char*)keyChild.begin(), out);
#else
bool ret = CECKey::TweakSecret((unsigned char*)keyChild.begin(), begin(), out);
#endif
UnlockObject(out);
keyChild.fCompressed = true;
keyChild.fValid = ret;
return ret;
}
bool CPubKey::Derive(CPubKey& pubkeyChild, unsigned char ccChild[32], unsigned int nChild, const unsigned char cc[32]) const {
assert(IsValid());
assert((nChild >> 31) == 0);
assert(begin() + 33 == end());
unsigned char out[64];
BIP32Hash(cc, nChild, *begin(), begin()+1, out);
memcpy(ccChild, out+32, 32);
#ifdef USE_SECP256K1
pubkeyChild = *this;
bool ret = secp256k1_ecdsa_pubkey_tweak_add((unsigned char*)pubkeyChild.begin(), pubkeyChild.size(), out);
#else
CECKey key;
bool ret = key.SetPubKey(*this);
ret &= key.TweakPublic(out);
key.GetPubKey(pubkeyChild, true);
#endif
return ret;
}
bool CExtKey::Derive(CExtKey &out, unsigned int nChild) const {
out.nDepth = nDepth + 1;
CKeyID id = key.GetPubKey().GetID();
memcpy(&out.vchFingerprint[0], &id, 4);
out.nChild = nChild;
return key.Derive(out.key, out.vchChainCode, nChild, vchChainCode);
}
void CExtKey::SetMaster(const unsigned char *seed, unsigned int nSeedLen) {
static const unsigned char hashkey[] = {'B','i','t','c','o','i','n',' ','s','e','e','d'};
unsigned char out[64];
LockObject(out);
CHMAC_SHA512(hashkey, sizeof(hashkey)).Write(seed, nSeedLen).Finalize(out);
key.Set(&out[0], &out[32], true);
memcpy(vchChainCode, &out[32], 32);
UnlockObject(out);
nDepth = 0;
nChild = 0;
memset(vchFingerprint, 0, sizeof(vchFingerprint));
}
CExtPubKey CExtKey::Neuter() const {
CExtPubKey ret;
ret.nDepth = nDepth;
memcpy(&ret.vchFingerprint[0], &vchFingerprint[0], 4);
ret.nChild = nChild;
ret.pubkey = key.GetPubKey();
memcpy(&ret.vchChainCode[0], &vchChainCode[0], 32);
return ret;
}
void CExtKey::Encode(unsigned char code[74]) const {
code[0] = nDepth;
memcpy(code+1, vchFingerprint, 4);
code[5] = (nChild >> 24) & 0xFF; code[6] = (nChild >> 16) & 0xFF;
code[7] = (nChild >> 8) & 0xFF; code[8] = (nChild >> 0) & 0xFF;
memcpy(code+9, vchChainCode, 32);
code[41] = 0;
assert(key.size() == 32);
memcpy(code+42, key.begin(), 32);
}
void CExtKey::Decode(const unsigned char code[74]) {
nDepth = code[0];
memcpy(vchFingerprint, code+1, 4);
nChild = (code[5] << 24) | (code[6] << 16) | (code[7] << 8) | code[8];
memcpy(vchChainCode, code+9, 32);
key.Set(code+42, code+74, true);
}
void CExtPubKey::Encode(unsigned char code[74]) const {
code[0] = nDepth;
memcpy(code+1, vchFingerprint, 4);
code[5] = (nChild >> 24) & 0xFF; code[6] = (nChild >> 16) & 0xFF;
code[7] = (nChild >> 8) & 0xFF; code[8] = (nChild >> 0) & 0xFF;
memcpy(code+9, vchChainCode, 32);
assert(pubkey.size() == 33);
memcpy(code+41, pubkey.begin(), 33);
}
void CExtPubKey::Decode(const unsigned char code[74]) {
nDepth = code[0];
memcpy(vchFingerprint, code+1, 4);
nChild = (code[5] << 24) | (code[6] << 16) | (code[7] << 8) | code[8];
memcpy(vchChainCode, code+9, 32);
pubkey.Set(code+41, code+74);
}
bool CExtPubKey::Derive(CExtPubKey &out, unsigned int nChild) const {
out.nDepth = nDepth + 1;
CKeyID id = pubkey.GetID();
memcpy(&out.vchFingerprint[0], &id, 4);
out.nChild = nChild;
return pubkey.Derive(out.pubkey, out.vchChainCode, nChild, vchChainCode);
}
bool ECC_InitSanityCheck() {
#ifdef USE_SECP256K1
return true;
#else
EC_KEY *pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
if(pkey == NULL)
return false;
EC_KEY_free(pkey);
// TODO Is there more EC functionality that could be missing?
return true;
#endif
}