bound assertions.

libdevcrypto/Common.cpp

@@ -120,10 +120,9 @@ bool dev::decrypt(Secret _k, bytesConstRef _cipher, bytes& _plain)
 {
 	bytes io = _cipher.toBytes();
 	crypto::decrypt(_k, io);
-	if (io.size())
-		_plain = std::move(io);
-	else
+	if (io.empty())
 		return false;
+	_plain = std::move(io);
 	return true;
 }
 

libdevcrypto/CryptoPP.cpp

@@ -23,19 +23,20 @@
 
 using namespace dev;
 using namespace dev::crypto;
-using namespace pp;
 using namespace CryptoPP;
 
 ECP::Point pp::PointFromPublic(Public const& _p)
 {
-	bytes prefixedKey(65);
-	prefixedKey[0] = 0x04;
-	memcpy(&prefixedKey[1], _p.data(), 64);
-	
 	ECP::Point p;
 	CryptoPP::DL_PublicKey_EC<CryptoPP::ECP> pub;
 	pub.AccessGroupParameters().Initialize(pp::secp256k1());
-	pub.GetGroupParameters().GetCurve().DecodePoint(p, prefixedKey.data(), 65);
+
+	bytes prefixedKey(pub.GetGroupParameters().GetEncodedElementSize(true));
+	prefixedKey[0] = 0x04;
+	assert(Public::size == prefixedKey.size() - 1);
+	memcpy(&prefixedKey[1], _p.data(), prefixedKey.size() - 1);
+	
+	pub.GetGroupParameters().GetCurve().DecodePoint(p, prefixedKey.data(), prefixedKey.size());
 	return std::move(p);
 }
 
@@ -58,12 +59,15 @@ void pp::PublicFromExponent(Integer const& _e, Public& _p)
 
 void pp::PublicFromDL_PublicKey_EC(CryptoPP::DL_PublicKey_EC<CryptoPP::ECP> const& _k, Public& _p)
 {
-	bytes prefixedKey(65);
+	bytes prefixedKey(_k.GetGroupParameters().GetEncodedElementSize(true));
 	_k.GetGroupParameters().GetCurve().EncodePoint(prefixedKey.data(), _k.GetPublicElement(), false);
-	memcpy(_p.data(), &prefixedKey[1], 64);
+	
+	static_assert(Public::size == 64, "Public key must be 64 bytes.");
+	assert(Public::size + 1 == _k.GetGroupParameters().GetEncodedElementSize(true));
+	memcpy(_p.data(), &prefixedKey[1], Public::size);
 }
 
 void pp::SecretFromDL_PrivateKey_EC(CryptoPP::DL_PrivateKey_EC<CryptoPP::ECP> const& _k, Secret& _s)
 {
-	_k.GetPrivateExponent().Encode(_s.data(), 32);
+	_k.GetPrivateExponent().Encode(_s.data(), Secret::size);
 }

libdevcrypto/EC.cpp

@@ -48,11 +48,12 @@ void dev::crypto::encrypt(Public const& _key, bytes& _plain)
 	e.AccessKey().AccessGroupParameters().Initialize(pp::secp256k1());
 	e.AccessKey().SetPublicElement(pp::PointFromPublic(_key));
 	size_t plen = _plain.size();
-	std::string c;
+	bytes c;
 	c.resize(e.CiphertextLength(plen));
-	e.Encrypt(pp::PRNG(), _plain.data(), plen, (byte*)c.data());
-	_plain.resize(c.size());
-	memcpy(_plain.data(), c.data(), c.size());
+	// todo: use StringSource with _plain as input and output.
+	e.Encrypt(pp::PRNG(), _plain.data(), plen, c.data());
+	bzero(_plain.data(), _plain.size());
+	_plain = std::move(c);
 }
 
 void dev::crypto::decrypt(Secret const& _k, bytes& _c)
@@ -61,11 +62,12 @@ void dev::crypto::decrypt(Secret const& _k, bytes& _c)
 	d.AccessKey().AccessGroupParameters().Initialize(pp::secp256k1());
 	d.AccessKey().SetPrivateExponent(pp::ExponentFromSecret(_k));
 	size_t clen = _c.size();
-	std::string p;
+	bytes p;
 	p.resize(d.MaxPlaintextLength(_c.size()));
-	DecodingResult r = d.Decrypt(pp::PRNG(), _c.data(), clen, (byte*)p.data());
+	// todo: use StringSource with _c as input and output.
+	DecodingResult r = d.Decrypt(pp::PRNG(), _c.data(), clen, p.data());
 	assert(r.messageLength);
 	_c.resize(r.messageLength);
-	memcpy(_c.data(), p.data(), _c.size());
+	_c = std::move(p);
 }