X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=src%2Fkey.cpp;h=fe8573e532a81b9dc9a392c0369fb2c1bfeb494e;hb=39d23056c0cf13b3e59648c159f2d4aff190992b;hp=4a7d7fd02803b10e0dbaa4a0cebadaa8b3c856fb;hpb=07bc41cd07f81fffadcf5b0fb8838e84a159389e;p=novacoin.git

diff --git a/src/key.cpp b/src/key.cpp
index 4a7d7fd..fe8573e 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -8,6 +8,7 @@
 #include <openssl/obj_mac.h>
 
 #include "key.h"
+#include "base58.h"
 
 // Generate a private key from just the secret parameter
 int EC_KEY_regenerate_key(EC_KEY *eckey, BIGNUM *priv_key)
@@ -161,7 +162,7 @@ const unsigned char vchMaxModHalfOrder[32] = {
     0xDF,0xE9,0x2F,0x46,0x68,0x1B,0x20,0xA0
 };
 
-const unsigned char vchZero[0] = {};
+const unsigned char *vchZero = NULL;
 
 
 
@@ -194,6 +195,7 @@ CKey::CKey(const CKey& b)
     if (pkey == NULL)
         throw key_error("CKey::CKey(const CKey&) : EC_KEY_dup failed");
     fSet = b.fSet;
+    fCompressedPubKey = b.fCompressedPubKey;
 }
 
 CKey& CKey::operator=(const CKey& b)
@@ -201,6 +203,7 @@ CKey& 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;
+    fCompressedPubKey = b.fCompressedPubKey;
     return (*this);
 }
 
@@ -224,6 +227,32 @@ bool CKey::CheckSignatureElement(const unsigned char *vch, int len, bool half) {
         CompareBigEndian(vch, len, half ? vchMaxModHalfOrder : vchMaxModOrder, 32) <= 0;
 }
 
+bool CKey::ReserealizeSignature(std::vector<unsigned char>& vchSig)
+{
+    if (vchSig.empty())
+        return false;
+
+    unsigned char *pos = &vchSig[0];
+    ECDSA_SIG *sig = d2i_ECDSA_SIG(NULL, (const unsigned char **)&pos, vchSig.size());
+    if (sig == NULL)
+        return false;
+
+    bool ret = false;
+    int nSize = i2d_ECDSA_SIG(sig, NULL);
+    if (nSize > 0) {
+        vchSig.resize(nSize); // grow or shrink as needed
+
+        pos = &vchSig[0];
+        i2d_ECDSA_SIG(sig, &pos);
+
+        ret = true;
+    }
+
+    ECDSA_SIG_free(sig);
+
+    return ret;
+}
+
 void CKey::MakeNewKey(bool fCompressed)
 {
     if (!EC_KEY_generate_key(pkey))
@@ -344,7 +373,7 @@ bool CKey::Sign(uint256 hash, std::vector<unsigned char>& vchSig)
     EC_GROUP_get_order(group, &order, NULL);
     BN_rshift1(&halforder, &order);
     // enforce low S values, by negating the value (modulo the order) if above order/2.
-    if (BN_cmp(sig->s, &halforder)) {
+    if (BN_cmp(sig->s, &halforder) > 0) {
         BN_sub(sig->s, &order, sig->s);
     }
     unsigned int nSize = ECDSA_size(pkey);
@@ -376,7 +405,7 @@ bool CKey::SignCompact(uint256 hash, std::vector<unsigned char>& vchSig)
     EC_GROUP_get_order(group, &order, NULL);
     BN_rshift1(&halforder, &order);
     // enforce low S values, by negating the value (modulo the order) if above order/2.
-    if (BN_cmp(sig->s, &halforder)) {
+    if (BN_cmp(sig->s, &halforder) > 0) {
         BN_sub(sig->s, &order, sig->s);
     }
     vchSig.clear();
@@ -385,8 +414,8 @@ bool CKey::SignCompact(uint256 hash, std::vector<unsigned char>& vchSig)
     int nBitsS = BN_num_bits(sig->s);
     if (nBitsR <= 256 && nBitsS <= 256)
     {
-        int nRecId = -1;
-        for (int i=0; i<4; i++)
+        int8_t nRecId = -1;
+        for (int8_t i=0; i<4; i++)
         {
             CKey keyRec;
             keyRec.fSet = true;
@@ -449,11 +478,34 @@ bool CKey::SetCompactSignature(uint256 hash, const std::vector<unsigned char>& v
 
 bool CKey::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)
+    if (vchSig.empty())
         return false;
 
-    return true;
+    // New versions of OpenSSL will reject non-canonical DER signatures. de/re-serialize first.
+    unsigned char *norm_der = NULL;
+    ECDSA_SIG *norm_sig = ECDSA_SIG_new();
+    const unsigned char* sigptr = &vchSig[0];
+    assert(norm_sig);
+    if (d2i_ECDSA_SIG(&norm_sig, &sigptr, vchSig.size()) == NULL)
+    {
+        /* As of OpenSSL 1.0.0p d2i_ECDSA_SIG frees and nulls the pointer on
+        * error. But OpenSSL's own use of this function redundantly frees the
+        * result. As ECDSA_SIG_free(NULL) is a no-op, and in the absence of a
+        * clear contract for the function behaving the same way is more
+        * conservative.
+        */
+        ECDSA_SIG_free(norm_sig);
+        return false;
+    }
+    int derlen = i2d_ECDSA_SIG(norm_sig, &norm_der);
+    ECDSA_SIG_free(norm_sig);
+    if (derlen <= 0)
+        return false;
+
+    // -1 = error, 0 = bad sig, 1 = good
+    bool ret = ECDSA_verify(0, (unsigned char*)&hash, sizeof(hash), norm_der, derlen, pkey) == 1;
+    OPENSSL_free(norm_der);
+    return ret;
 }
 
 bool CKey::VerifyCompact(uint256 hash, const std::vector<unsigned char>& vchSig)
@@ -481,3 +533,674 @@ bool CKey::IsValid()
     key2.SetSecret(secret, fCompr);
     return GetPubKey() == key2.GetPubKey();
 }
+
+CPoint::CPoint()
+{
+    std::string err;
+    group = NULL;
+    point = NULL;
+    ctx   = NULL;
+
+    group = EC_GROUP_new_by_curve_name(NID_secp256k1);
+    if (!group) {
+        err = "EC_KEY_new_by_curve_name failed.";
+        goto finish;
+    }
+
+    point = EC_POINT_new(group);
+    if (!point) {
+        err = "EC_POINT_new failed.";
+        goto finish;
+    }
+
+    ctx = BN_CTX_new();
+    if (!ctx) {
+        err = "BN_CTX_new failed.";
+        goto finish;
+    }
+
+    return;
+
+finish:
+    if (group) EC_GROUP_free(group);
+    if (point) EC_POINT_free(point);
+    throw std::runtime_error(std::string("CPoint::CPoint() :  - ") + err);
+}
+
+bool CPoint::operator!=(const CPoint &a)
+{
+    if (EC_POINT_cmp(group, point, a.point, ctx) != 0)
+        return true;
+    return false;
+}
+CPoint::~CPoint()
+{
+    if (point) EC_POINT_free(point);
+    if (group) EC_GROUP_free(group);
+    if (ctx)   BN_CTX_free(ctx);
+}
+
+// Initialize from octets stream
+bool CPoint::setBytes(const std::vector<unsigned char> &vchBytes)
+{
+    if (!EC_POINT_oct2point(group, point, &vchBytes[0], vchBytes.size(), ctx)) {
+        return false;
+    }
+    return true;
+}
+
+// Initialize from octets stream
+bool CPoint::setPubKey(const CPubKey &vchPubKey)
+{
+    return setBytes(vchPubKey.Raw());
+}
+
+// Serialize to octets stream
+bool CPoint::getBytes(std::vector<unsigned char> &vchBytes)
+{
+    unsigned int nSize = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED, NULL, 0, ctx);
+    vchBytes.resize(nSize);
+    if (!(nSize == EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED, &vchBytes[0], nSize, ctx))) {
+        return false;
+    }
+    return true;
+}
+
+// ECC multiplication by specified multiplier
+bool CPoint::ECMUL(const CBigNum &bnMultiplier)
+{
+    if (!EC_POINT_mul(group, point, NULL, point, &bnMultiplier, NULL)) {
+        printf("CPoint::ECMUL() : EC_POINT_mul failed");
+        return false;
+    }
+
+    return true;
+}
+
+// Calculate G*m + q
+bool CPoint::ECMULGEN(const CBigNum &bnMultiplier, const CPoint &qPoint)
+{
+    if (!EC_POINT_mul(group, point, &bnMultiplier, qPoint.point, BN_value_one(), NULL)) {
+        printf("CPoint::ECMULGEN() : EC_POINT_mul failed.");
+        return false;
+    }
+
+    return true;
+}
+
+// CMalleablePubKey
+
+void CMalleablePubKey::GetVariant(CPubKey &R, CPubKey &vchPubKeyVariant)
+{
+    EC_KEY *eckey = NULL;
+    eckey = EC_KEY_new_by_curve_name(NID_secp256k1);
+    if (eckey == NULL) {
+        throw key_error("CMalleablePubKey::GetVariant() : EC_KEY_new_by_curve_name failed");
+    }
+
+    // Use standard key generation function to get r and R values.
+    //
+    // r will be presented by private key;
+    // R is ECDSA public key which calculated as G*r
+    if (!EC_KEY_generate_key(eckey)) {
+        throw key_error("CMalleablePubKey::GetVariant() : EC_KEY_generate_key failed");
+    }
+
+    EC_KEY_set_conv_form(eckey, POINT_CONVERSION_COMPRESSED);
+
+    int nSize = i2o_ECPublicKey(eckey, NULL);
+    if (!nSize) {
+        throw key_error("CMalleablePubKey::GetVariant() : i2o_ECPublicKey failed");
+    }
+
+    std::vector<unsigned char> vchPubKey(nSize, 0);
+    unsigned char* pbegin_R = &vchPubKey[0];
+
+    if (i2o_ECPublicKey(eckey, &pbegin_R) != nSize) {
+        throw key_error("CMalleablePubKey::GetVariant() : i2o_ECPublicKey returned unexpected size");
+    }
+
+    // R = G*r
+    R = CPubKey(vchPubKey);
+
+    // OpenSSL BIGNUM representation of r value
+    CBigNum bnr;
+    bnr = *(CBigNum*) EC_KEY_get0_private_key(eckey);
+    EC_KEY_free(eckey);
+
+    CPoint point;
+    if (!point.setPubKey(pubKeyL)) {
+        throw key_error("CMalleablePubKey::GetVariant() : Unable to decode L value");
+    }
+
+    // Calculate L*r
+    point.ECMUL(bnr);
+
+    std::vector<unsigned char> vchLr;
+    if (!point.getBytes(vchLr)) {
+        throw key_error("CMalleablePubKey::GetVariant() : Unable to convert Lr value");
+    }
+
+    // Calculate Hash(L*r) and then get a BIGNUM representation of hash value.
+    CBigNum bnHash;
+    bnHash.setuint160(Hash160(vchLr));
+
+    CPoint pointH;
+    pointH.setPubKey(pubKeyH);
+
+    CPoint P;
+    // Calculate P = Hash(L*r)*G + H
+    P.ECMULGEN(bnHash, pointH);
+
+    if (P.IsInfinity()) {
+        throw key_error("CMalleablePubKey::GetVariant() : P is infinity");
+    }
+
+    std::vector<unsigned char> vchResult;
+    P.getBytes(vchResult);
+
+    vchPubKeyVariant = CPubKey(vchResult);
+}
+
+std::string CMalleablePubKey::ToString() const
+{
+    CDataStream ssKey(SER_NETWORK, PROTOCOL_VERSION);
+    ssKey << *this;
+    std::vector<unsigned char> vch(ssKey.begin(), ssKey.end());
+
+    return EncodeBase58Check(vch);
+}
+
+bool CMalleablePubKey::SetString(const std::string& strMalleablePubKey)
+{
+    std::vector<unsigned char> vchTemp;
+    if (!DecodeBase58Check(strMalleablePubKey, vchTemp)) {
+        throw key_error("CMalleablePubKey::SetString() : Provided key data seems corrupted.");
+    }
+
+    CDataStream ssKey(vchTemp, SER_NETWORK, PROTOCOL_VERSION);
+    ssKey >> *this;
+
+    return IsValid();
+}
+
+bool CMalleablePubKey::operator==(const CMalleablePubKey &b)
+{
+    return (nVersion == b.nVersion &&
+            pubKeyL == b.pubKeyL &&
+            pubKeyH == b.pubKeyH);
+}
+
+
+// CMalleableKey
+
+void CMalleableKey::Reset()
+{
+    vchSecretL.clear();
+    vchSecretH.clear();
+
+    nVersion = 0;
+}
+
+void CMalleableKey::MakeNewKeys()
+{
+    CKey L, H;
+    bool fCompressed = true;
+
+    L.MakeNewKey(true);
+    H.MakeNewKey(true);
+
+    vchSecretL = L.GetSecret(fCompressed);
+    vchSecretH = H.GetSecret(fCompressed);
+
+    nVersion = CURRENT_VERSION;
+}
+
+CMalleableKey::CMalleableKey()
+{
+    Reset();
+}
+
+CMalleableKey::CMalleableKey(const CMalleableKey &b)
+{
+    SetSecrets(b.vchSecretL, b.vchSecretH);
+}
+
+CMalleableKey::CMalleableKey(const CSecret &L, const CSecret &H)
+{
+    SetSecrets(L, H);
+}
+
+CMalleableKey& CMalleableKey::operator=(const CMalleableKey &b)
+{
+    SetSecrets(b.vchSecretL, b.vchSecretH);
+
+    return (*this);
+}
+
+CMalleableKey::~CMalleableKey()
+{
+}
+
+bool CMalleableKey::IsNull() const
+{
+    return nVersion != CURRENT_VERSION;
+}
+
+bool CMalleableKey::SetSecrets(const CSecret &pvchSecretL, const CSecret &pvchSecretH)
+{
+    Reset();
+    CKey L, H;
+
+    if (pvchSecretL.size() != 32 || !pvchSecretH.size() != 32 || !L.SetSecret(pvchSecretL, true) || !H.SetSecret(pvchSecretH, true))
+    {
+        nVersion = 0;
+        return false;
+    }
+
+    vchSecretL = pvchSecretL;
+    vchSecretH = pvchSecretH;
+    nVersion = CURRENT_VERSION;
+
+    return true;
+}
+
+void CMalleableKey::GetSecrets(CSecret &pvchSecretL, CSecret &pvchSecretH) const
+{
+    pvchSecretL = vchSecretL;
+    pvchSecretH = vchSecretH;
+}
+
+CMalleablePubKey CMalleableKey::GetMalleablePubKey() const
+{
+    CKey L, H;
+    L.SetSecret(vchSecretL, true);
+    H.SetSecret(vchSecretH, true);
+
+    std::vector<unsigned char> vchPubKeyL = L.GetPubKey().Raw();
+    std::vector<unsigned char> vchPubKeyH = H.GetPubKey().Raw();
+
+    return CMalleablePubKey(vchPubKeyL, vchPubKeyH);
+}
+
+// Check ownership
+bool CMalleableKey::CheckKeyVariant(const CPubKey &R, const CPubKey &vchPubKeyVariant) const
+{
+    if (IsNull()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Attempting to run on NULL key object.");
+    }
+
+    if (!R.IsValid()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : R is invalid");
+    }
+
+    if (!vchPubKeyVariant.IsValid()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : public key variant is invalid");
+    }
+
+    CPoint point_R;
+    if (!point_R.setPubKey(R)) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Unable to decode R value");
+    }
+
+    CKey H;
+    H.SetSecret(vchSecretH, true);
+    std::vector<unsigned char> vchPubKeyH = H.GetPubKey().Raw();
+
+    CPoint point_H;
+    if (!point_H.setPubKey(vchPubKeyH)) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Unable to decode H value");
+    }
+
+    CPoint point_P;
+    if (!point_P.setPubKey(vchPubKeyVariant)) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Unable to decode P value");
+    }
+
+    // Infinity points are senseless
+    if (point_P.IsInfinity()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : P is infinity");
+    }
+
+    CBigNum bnl;
+    bnl.setBytes(std::vector<unsigned char>(vchSecretL.begin(), vchSecretL.end()));
+
+    point_R.ECMUL(bnl);
+
+    std::vector<unsigned char> vchRl;
+    if (!point_R.getBytes(vchRl)) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Unable to convert Rl value");
+    }
+
+    // Calculate Hash(R*l)
+    CBigNum bnHash;
+    bnHash.setuint160(Hash160(vchRl));
+
+    CPoint point_Ps;
+    // Calculate Ps = Hash(L*r)*G + H
+    point_Ps.ECMULGEN(bnHash, point_H);
+
+    // Infinity points are senseless
+    if (point_Ps.IsInfinity()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Ps is infinity");
+    }
+
+    // Check ownership
+    if (point_Ps != point_P) {
+        return false;
+    }
+
+    return true;
+}
+
+// Check ownership and restore private key
+bool CMalleableKey::CheckKeyVariant(const CPubKey &R, const CPubKey &vchPubKeyVariant, CKey &privKeyVariant) const
+{
+    if (IsNull()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Attempting to run on NULL key object.");
+    }
+
+    if (!R.IsValid()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : R is invalid");
+    }
+
+    if (!vchPubKeyVariant.IsValid()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : public key variant is invalid");
+    }
+
+    CPoint point_R;
+    if (!point_R.setPubKey(R)) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Unable to decode R value");
+    }
+
+    CKey H;
+    H.SetSecret(vchSecretH, true);
+    std::vector<unsigned char> vchPubKeyH = H.GetPubKey().Raw();
+
+    CPoint point_H;
+    if (!point_H.setPubKey(vchPubKeyH)) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Unable to decode H value");
+    }
+
+    CPoint point_P;
+    if (!point_P.setPubKey(vchPubKeyVariant)) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Unable to decode P value");
+    }
+
+    // Infinity points are senseless
+    if (point_P.IsInfinity()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : P is infinity");
+    }
+
+    CBigNum bnl;
+    bnl.setBytes(std::vector<unsigned char>(vchSecretL.begin(), vchSecretL.end()));
+
+    point_R.ECMUL(bnl);
+
+    std::vector<unsigned char> vchRl;
+    if (!point_R.getBytes(vchRl)) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Unable to convert Rl value");
+    }
+
+    // Calculate Hash(R*l)
+    CBigNum bnHash;
+    bnHash.setuint160(Hash160(vchRl));
+
+    CPoint point_Ps;
+    // Calculate Ps = Hash(L*r)*G + H
+    point_Ps.ECMULGEN(bnHash, point_H);
+
+    // Infinity points are senseless
+    if (point_Ps.IsInfinity()) {
+        throw key_error("CMalleableKey::CheckKeyVariant() : Ps is infinity");
+    }
+
+    // Check ownership
+    if (point_Ps != point_P) {
+        return false;
+    }
+
+    // OpenSSL BIGNUM representation of the second private key from (l, h) pair
+    CBigNum bnh;
+    bnh.setBytes(std::vector<unsigned char>(vchSecretH.begin(), vchSecretH.end()));
+
+    // Calculate p = Hash(R*l) + h
+    CBigNum bnp = bnHash + bnh;
+
+    std::vector<unsigned char> vchp = bnp.getBytes();
+    privKeyVariant.SetSecret(CSecret(vchp.begin(), vchp.end()), true);
+
+    return true;
+}
+
+std::string CMalleableKey::ToString() const
+{
+    CDataStream ssKey(SER_NETWORK, PROTOCOL_VERSION);
+    ssKey << *this;
+    std::vector<unsigned char> vch(ssKey.begin(), ssKey.end());
+
+    return EncodeBase58Check(vch);
+}
+
+bool CMalleableKey::SetString(const std::string& strMutableKey)
+{
+    std::vector<unsigned char> vchTemp;
+    if (!DecodeBase58Check(strMutableKey, vchTemp)) {
+        throw key_error("CMalleableKey::SetString() : Provided key data seems corrupted.");
+    }
+
+    CDataStream ssKey(vchTemp, SER_NETWORK, PROTOCOL_VERSION);
+    ssKey >> *this;
+
+    return IsNull();
+}
+
+// CMalleableKeyView
+
+CMalleableKeyView::CMalleableKeyView(const CMalleableKey &b)
+{
+    if (b.vchSecretL.size() != 32)
+        throw key_error("CMalleableKeyView::CMalleableKeyView() : L size must be 32 bytes");
+
+    if (b.vchSecretH.size() != 32)
+        throw key_error("CMalleableKeyView::CMalleableKeyView() : L size must be 32 bytes");
+
+    vchSecretL = b.vchSecretL;
+
+    CKey H;
+    H.SetSecret(b.vchSecretH, true);
+
+    vchPubKeyH = H.GetPubKey().Raw();
+    nVersion = b.nVersion;
+}
+
+CMalleableKeyView::CMalleableKeyView(const CMalleableKeyView &b)
+{
+    vchSecretL = b.vchSecretL;
+    vchPubKeyH = b.vchPubKeyH;
+    nVersion = CURRENT_VERSION;
+}
+
+CMalleableKeyView::CMalleableKeyView(const CSecret &L, const CPubKey &pvchPubKeyH)
+{
+    vchSecretL = L;
+    vchPubKeyH = pvchPubKeyH.Raw();
+    nVersion = CURRENT_VERSION;
+}
+
+CMalleableKeyView& CMalleableKeyView::operator=(const CMalleableKey &b)
+{
+    vchSecretL = b.vchSecretL;
+
+    CKey H;
+    H.SetSecret(b.vchSecretH, true);
+    vchPubKeyH = H.GetPubKey().Raw();
+    nVersion = b.nVersion;
+
+    return (*this);
+}
+
+CMalleableKeyView::~CMalleableKeyView()
+{
+}
+
+CMalleablePubKey CMalleableKeyView::GetMalleablePubKey() const
+{
+    CKey keyL;
+    keyL.SetSecret(vchSecretL, true);
+    return CMalleablePubKey(keyL.GetPubKey(), vchPubKeyH);
+}
+
+// Check ownership
+bool CMalleableKeyView::CheckKeyVariant(const CPubKey &R, const CPubKey &vchPubKeyVariant) const
+{
+    if (!R.IsValid()) {
+        throw key_error("CMalleableKeyView::CheckKeyVariant() : R is invalid");
+    }
+
+    if (!vchPubKeyVariant.IsValid()) {
+        throw key_error("CMalleableKeyView::CheckKeyVariant() : public key variant is invalid");
+    }
+
+    CPoint point_R;
+    if (!point_R.setPubKey(R)) {
+        throw key_error("CMalleableKeyView::CheckKeyVariant() : Unable to decode R value");
+    }
+
+    CPoint point_H;
+    if (!point_H.setPubKey(vchPubKeyH)) {
+        throw key_error("CMalleableKeyView::CheckKeyVariant() : Unable to decode H value");
+    }
+
+    CPoint point_P;
+    if (!point_P.setPubKey(vchPubKeyVariant)) {
+        throw key_error("CMalleableKeyView::CheckKeyVariant() : Unable to decode P value");
+    }
+
+    // Infinity points are senseless
+    if (point_P.IsInfinity()) {
+        throw key_error("CMalleableKeyView::CheckKeyVariant() : P is infinity");
+    }
+
+    CBigNum bnl;
+    bnl.setBytes(std::vector<unsigned char>(vchSecretL.begin(), vchSecretL.end()));
+
+    point_R.ECMUL(bnl);
+
+    std::vector<unsigned char> vchRl;
+    if (!point_R.getBytes(vchRl)) {
+        throw key_error("CMalleableKeyView::CheckKeyVariant() : Unable to convert Rl value");
+    }
+
+    // Calculate Hash(R*l)
+    CBigNum bnHash;
+    bnHash.setuint160(Hash160(vchRl));
+
+    CPoint point_Ps;
+    // Calculate Ps = Hash(L*r)*G + H
+    point_Ps.ECMULGEN(bnHash, point_H);
+
+    // Infinity points are senseless
+    if (point_Ps.IsInfinity()) {
+        throw key_error("CMalleableKeyView::CheckKeyVariant() : Ps is infinity");
+    }
+
+    // Check ownership
+    if (point_Ps != point_P) {
+        return false;
+    }
+
+    return true;
+}
+
+std::string CMalleableKeyView::ToString() const
+{
+    CDataStream ssKey(SER_NETWORK, PROTOCOL_VERSION);
+    ssKey << *this;
+    std::vector<unsigned char> vch(ssKey.begin(), ssKey.end());
+
+    return EncodeBase58Check(vch);
+}
+
+bool CMalleableKeyView::SetString(const std::string& strMutableKey)
+{
+    std::vector<unsigned char> vchTemp;
+    if (!DecodeBase58Check(strMutableKey, vchTemp)) {
+        throw key_error("CMalleableKeyView::SetString() : Provided key data seems corrupted.");
+    }
+
+    CDataStream ssKey(vchTemp, SER_NETWORK, PROTOCOL_VERSION);
+    ssKey >> *this;
+
+    return IsNull();
+}
+
+bool CMalleableKeyView::IsNull() const
+{
+    return nVersion != CURRENT_VERSION;
+}
+
+//// Asymmetric encryption
+
+void CPubKey::EncryptData(const std::vector<unsigned char>& data, std::vector<unsigned char>& encrypted)
+{
+    CKey key;
+    key.SetPubKey(*this);
+
+    key.EncryptData(data, encrypted);
+}
+
+void CKey::EncryptData(const std::vector<unsigned char>& data, std::vector<unsigned char>& encrypted)
+{
+    ies_ctx_t *ctx;
+    char error[1024] = "Unknown error";
+    cryptogram_t *cryptogram;
+
+    ctx = create_context(pkey);
+    if (!EC_KEY_get0_public_key(ctx->user_key))
+        throw key_error("Given EC key is not public key");
+
+    cryptogram = ecies_encrypt(ctx, (unsigned char*)&data[0], data.size(), error);
+    if (cryptogram == NULL) {
+        free(ctx);
+        ctx = NULL;
+        throw key_error(std::string("Error in encryption: %s") + error);
+    }
+
+    encrypted.resize(cryptogram_data_sum_length(cryptogram));
+    unsigned char *key_data = cryptogram_key_data(cryptogram);
+    memcpy(&encrypted[0], key_data, encrypted.size());
+    cryptogram_free(cryptogram);
+    free(ctx);
+}
+
+void CKey::DecryptData(const std::vector<unsigned char>& encrypted, std::vector<unsigned char>& data)
+{
+    ies_ctx_t *ctx;
+    char error[1024] = "Unknown error";
+    cryptogram_t *cryptogram;
+    size_t length;
+    unsigned char *decrypted;
+
+    ctx = create_context(pkey);
+    if (!EC_KEY_get0_private_key(ctx->user_key))
+        throw key_error("Given EC key is not private key");
+
+    size_t key_length = ctx->stored_key_length;
+    size_t mac_length = EVP_MD_size(ctx->md);
+    cryptogram = cryptogram_alloc(key_length, mac_length, encrypted.size() - key_length - mac_length);
+
+    memcpy(cryptogram_key_data(cryptogram), &encrypted[0], encrypted.size());
+
+    decrypted = ecies_decrypt(ctx, cryptogram, &length, error);
+    cryptogram_free(cryptogram);
+    free(ctx);
+
+    if (decrypted == NULL) {
+        throw key_error(std::string("Error in decryption: %s") + error);
+    }
+
+    data.resize(length);
+    memcpy(&data[0], decrypted, length);
+    free(decrypted);
+}