public commit

1 files changed, 190 insertions, 0 deletions

diff --git a/src/key.h b/src/key.h
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+++ b/src/key.h
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+// Copyright (c) 2009 Satoshi Nakamoto
+// Distributed under the MIT/X11 software license, see the accompanying
+// file license.txt or http://www.opensource.org/licenses/mit-license.php.
+
+
+// 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
+
+
+
+class key_error : public std::runtime_error
+{
+public:
+    explicit key_error(const std::string& str) : std::runtime_error(str) {}
+};
+
+
+// secure_allocator is defined is serialize.h
+typedef vector<unsigned char, secure_allocator<unsigned char> > CPrivKey;
+
+
+
+class CKey
+{
+protected:
+    EC_KEY* pkey;
+
+public:
+    CKey()
+    {
+        pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
+        if (pkey == NULL)
+            throw key_error("CKey::CKey() : EC_KEY_new_by_curve_name failed");
+    }
+
+    CKey(const CKey& b)
+    {
+        pkey = EC_KEY_dup(b.pkey);
+        if (pkey == NULL)
+            throw key_error("CKey::CKey(const CKey&) : EC_KEY_dup failed");
+    }
+
+    CKey& operator=(const CKey& b)
+    {
+        if (!EC_KEY_copy(pkey, b.pkey))
+            throw key_error("CKey::operator=(const CKey&) : EC_KEY_copy failed");
+        return (*this);
+    }
+
+    ~CKey()
+    {
+        EC_KEY_free(pkey);
+    }
+
+    void MakeNewKey()
+    {
+        if (!EC_KEY_generate_key(pkey))
+            throw key_error("CKey::MakeNewKey() : EC_KEY_generate_key failed");
+    }
+
+    bool SetPrivKey(const CPrivKey& vchPrivKey)
+    {
+        const unsigned char* pbegin = &vchPrivKey[0];
+        if (!d2i_ECPrivateKey(&pkey, &pbegin, vchPrivKey.size()))
+            return false;
+        return true;
+    }
+
+    // Load a raw 32-byte scalar, the form BIP32 derivation produces.
+    //
+    // SetPrivKey above takes DER and cannot be used for this: handing it a
+    // scalar makes d2i_ECPrivateKey fail, and if the caller ignores the return
+    // value -- as one attempt at this did -- the key is left with no material
+    // at all and the address it produces has no private half. Coins paid there
+    // are gone. Hence a separate entry point rather than a looser SetPrivKey.
+    //
+    // The public half is computed here rather than read from anywhere:
+    // pub = G * secret.
+    bool SetSecret(const std::vector<unsigned char>& vchSecret)
+    {
+        if (vchSecret.size() != 32)
+            return false;
+
+        bool fOk = false;
+        BIGNUM* bn = BN_bin2bn(&vchSecret[0], 32, NULL);
+        EC_POINT* pubkey = NULL;
+        if (bn && EC_KEY_set_private_key(pkey, bn))
+        {
+            const EC_GROUP* group = EC_KEY_get0_group(pkey);
+            pubkey = EC_POINT_new(group);
+            if (pubkey &&
+                EC_POINT_mul(group, pubkey, bn, NULL, NULL, NULL) &&
+                EC_KEY_set_public_key(pkey, pubkey))
+                fOk = true;
+        }
+        if (pubkey)
+            EC_POINT_free(pubkey);
+        if (bn)
+            BN_clear_free(bn);   // it held the secret
+        return fOk;
+    }
+
+    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 vector<unsigned char>& vchPubKey)
+    {
+        const unsigned char* pbegin = &vchPubKey[0];
+        if (!o2i_ECPublicKey(&pkey, &pbegin, vchPubKey.size()))
+            return false;
+        return true;
+    }
+
+    vector<unsigned char> GetPubKey() const
+    {
+        unsigned int nSize = i2o_ECPublicKey(pkey, NULL);
+        if (!nSize)
+            throw key_error("CKey::GetPubKey() : i2o_ECPublicKey failed");
+        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, 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))
+            return false;
+        vchSig.resize(nSize);
+        memcpy(&vchSig[0], pchSig, nSize);
+        return true;
+    }
+
+    bool Verify(uint256 hash, const 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;
+    }
+
+    static bool Sign(const CPrivKey& vchPrivKey, uint256 hash, vector<unsigned char>& vchSig)
+    {
+        CKey key;
+        if (!key.SetPrivKey(vchPrivKey))
+            return false;
+        return key.Sign(hash, vchSig);
+    }
+
+    static bool Verify(const vector<unsigned char>& vchPubKey, uint256 hash, const vector<unsigned char>& vchSig)
+    {
+        CKey key;
+        if (!key.SetPubKey(vchPubKey))
+            return false;
+        return key.Verify(hash, vchSig);
+    }
+};