#include "serialize.h"
#include "uint256.h"
-#include "base58.h"
// secp160k1
// const unsigned int PRIVATE_KEY_SIZE = 192;
// see www.keylength.com
// script supports up to 75 for single byte push
-// Generate a private key from just the secret parameter
-int static inline 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 nonzero, additional checks are performed
-int static inline 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;
-}
+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
{
// CSecret is a serialization of just the secret parameter (32 bytes)
typedef std::vector<unsigned char, secure_allocator<unsigned char> > CSecret;
+/** An encapsulated OpenSSL Elliptic Curve key (public and/or private) */
class CKey
{
protected:
EC_KEY* pkey;
bool fSet;
+ bool fCompressedPubKey;
+
+ void SetCompressedPubKey()
+ {
+ EC_KEY_set_conv_form(pkey, POINT_CONVERSION_COMPRESSED);
+ fCompressedPubKey = true;
+ }
public:
- CKey()
+
+ 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);
return !fSet;
}
- void MakeNewKey()
+ bool IsCompressed() const
+ {
+ return fCompressedPubKey;
+ }
+
+ void MakeNewKey(bool fCompressed)
{
if (!EC_KEY_generate_key(pkey))
throw key_error("CKey::MakeNewKey() : EC_KEY_generate_key failed");
+ if (fCompressed)
+ SetCompressedPubKey();
fSet = true;
}
return true;
}
- bool SetSecret(const CSecret& vchSecret)
+ bool SetSecret(const CSecret& vchSecret, bool fCompressed = false)
{
EC_KEY_free(pkey);
pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
}
BN_clear_free(bn);
fSet = true;
+ if (fCompressed || fCompressedPubKey)
+ SetCompressedPubKey();
return true;
}
- CSecret GetSecret() const
+ CSecret GetSecret(bool &fCompressed) const
{
CSecret vchRet;
vchRet.resize(32);
int n=BN_bn2bin(bn,&vchRet[32 - nBytes]);
if (n != nBytes)
throw key_error("CKey::GetSecret(): BN_bn2bin failed");
+ fCompressed = fCompressedPubKey;
return vchRet;
}
if (!o2i_ECPublicKey(&pkey, &pbegin, vchPubKey.size()))
return false;
fSet = true;
+ if (vchPubKey.size() == 33)
+ SetCompressedPubKey();
return true;
}
bool Sign(uint256 hash, std::vector<unsigned char>& vchSig)
{
- vchSig.clear();
- unsigned char pchSig[10000];
- unsigned int nSize = 0;
- if (!ECDSA_sign(0, (unsigned char*)&hash, sizeof(hash), pchSig, &nSize, pkey))
+ 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);
- memcpy(&vchSig[0], pchSig, nSize);
+ }
+ vchSig.resize(nSize); // Shrink to fit actual size
return true;
}
{
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())
{
if (nRecId == -1)
throw key_error("CKey::SignCompact() : unable to construct recoverable key");
- vchSig[0] = nRecId+27;
+ 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;
{
if (vchSig.size() != 65)
return false;
- if (vchSig[0]<27 || vchSig[0]>=31)
+ int nV = vchSig[0];
+ if (nV<27 || nV>=35)
return false;
ECDSA_SIG *sig = ECDSA_SIG_new();
BN_bin2bn(&vchSig[1],32,sig->r);
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)
+ 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;
}
- // Get the address corresponding to this key
- CBitcoinAddress GetAddress() const
- {
- return CBitcoinAddress(GetPubKey());
- }
-
bool IsValid()
{
if (!fSet)
return false;
- CSecret secret = GetSecret();
+ bool fCompr;
+ CSecret secret = GetSecret(fCompr);
CKey key2;
- key2.SetSecret(secret);
+ key2.SetSecret(secret, fCompr);
return GetPubKey() == key2.GetPubKey();
}
};