eccrypto.h

一个DES,RSA,MD5,RC4等加密算法的源码

		: Base(oid, Q) {}													\
	Self(const EC &ec, const Point &G, const Integer &n, const Point &Q)	\
		: Base(ec, G, n, Q) {}												\
	Self(BufferedTransformation &bt)										\
		: Base(bt) {}
		
/// Elliptic Curve Private Key
template <class EC>
class ECPrivateKey : public ECPublicKey<EC>
{
public:
	typedef typename EC::Point Point;

	ECPrivateKey(const ECParameters<EC> &params, const Point &Q, const Integer &d)
		: ECPublicKey<EC>(params, Q), m_d(d) {}
	ECPrivateKey(const OID &oid, const Point &Q, const Integer &d)
		: ECPublicKey<EC>(oid, Q), m_d(d) {}
	ECPrivateKey(const EC &ec, const Point &G, const Integer &n, const Point &Q, const Integer &d)
		: ECPublicKey<EC>(ec, G, n, Q), m_d(d) {}
	// generate a random private key
	ECPrivateKey(RandomNumberGenerator &rng, const ECParameters<EC> &params)
		: ECPublicKey<EC>(params, Point()) {Randomize(rng);}
	ECPrivateKey(RandomNumberGenerator &rng, const OID &oid)
		: ECPublicKey<EC>(oid, Point()) {Randomize(rng);}
	ECPrivateKey(RandomNumberGenerator &rng, const EC &ec, const Point &G, const Integer &n)
		: ECPublicKey<EC>(ec, G, n, Point()) {Randomize(rng);}
	// decode private key
	ECPrivateKey(BufferedTransformation &bt);

	void DEREncode(BufferedTransformation &bt) const;

	const Integer& GetPrivateExponent() const {return m_d;}

protected:
	typedef typename EC::FieldElement FieldElement;
	void Randomize(RandomNumberGenerator &rng);
	void RawDecode(BERSequenceDecoder &bt, bool needParameters);

	Integer m_d;
};

#define EC_PRIVATE_KEY_CONSTRUCTORS(Self, Base)								\
	Self(const ECPrivateKey<EC> &key)										\
		: Base(key) {}														\
	Self(const ECParameters<EC> &params, const Point &Q, const Integer &d)	\
		: Base(params, Q, d) {}												\
	Self(const OID& oid, const Point &Q, const Integer &d)					\
		: Base(oid, Q, d) {}												\
	Self(const EC &ec, const Point &G, const Integer &n, const Point &Q, const Integer &d)	\
		: Base(ec, G, n, Q, d) {}											\
	Self(RandomNumberGenerator &rng, const ECParameters<EC> &params)		\
		: Base(rng, params) {}												\
	Self(RandomNumberGenerator &rng, const OID& oid)						\
		: Base(rng, oid) {}													\
	Self(RandomNumberGenerator &rng, const EC &ec, const Point &G, const Integer &n)	\
		: Base(rng, ec, G, n) {}											\
	Self(BufferedTransformation &bt)										\
		: Base(bt) {}

/// Elliptic Curve Digest Signature Verifier
template <class EC, ECSignatureScheme SS = ECNR>
class ECDigestVerifier : public ECPublicKey<EC>, public PK_WithPrecomputation<DigestVerifier>
{
public:
	typedef typename EC::Point Point;

	EC_PUBLIC_KEY_CONSTRUCTORS(ECDigestVerifier, ECPublicKey<EC>)
	
	bool VerifyDigest(const byte *digest, unsigned int digestLen, const byte *signature) const;

	unsigned int MaxDigestLength() const {return 0xffff;}
	unsigned int DigestSignatureLength() const {return 2*ExponentLength();}

	// exposed for validation testing
	bool RawVerify(const Integer &e, const Integer &n, const Integer &s) const;
};

/// Elliptic Curve Digest Signer
template <class EC, ECSignatureScheme SS = ECNR>
class ECDigestSigner : public ECPrivateKey<EC>, public PK_WithPrecomputation<DigestSigner>
{
public:
	typedef typename EC::Point Point;

	EC_PRIVATE_KEY_CONSTRUCTORS(ECDigestSigner, ECPrivateKey<EC>)

	void SignDigest(RandomNumberGenerator &, const byte *digest, unsigned int digestLen, byte *signature) const;

	unsigned int MaxDigestLength() const {return 0xffff;}
	unsigned int DigestSignatureLength() const {return 2*ExponentLength();}

	/// exposed for validation testing
	void RawSign(const Integer &k, const Integer &e, Integer &n, Integer &s) const;
};

/// Elliptic Curve Message Signer
template <class EC, class H, ECSignatureScheme SS = ECNR>
class ECSigner : public SignerTemplate<ECDigestSigner<EC, SS>, H>, public PK_WithPrecomputation<PK_Signer>
{
	typedef ECDigestSigner<EC, SS> Base;
public:
	typedef typename EC::Point Point;

	EC_PRIVATE_KEY_CONSTRUCTORS(ECSigner, Base)
};

/// Elliptic Curve Message Signature Verifier
template <class EC, class H, ECSignatureScheme SS = ECNR>
class ECVerifier : public VerifierTemplate<ECDigestVerifier<EC, SS>, H>, public PK_WithPrecomputation<PK_Verifier>
{
	typedef ECDigestVerifier<EC, SS> Base;
public:
	typedef typename EC::Point Point;
	
	EC_PUBLIC_KEY_CONSTRUCTORS(ECVerifier, Base)
};

/// Elliptic Curve ECIES, AKA <a href="http://www.weidai.com/scan-mirror/ca.html#EC-DHAES">EC-DHAES</a>
template <class EC, class MAC = HMAC<SHA>, class KDF = P1363_KDF2<SHA> >
class ECEncryptor : public ECPublicKey<EC>, public PK_WithPrecomputation<PK_Encryptor>
{
public:
	typedef typename EC::Point Point;
	
	EC_PUBLIC_KEY_CONSTRUCTORS(ECEncryptor, ECPublicKey<EC>)

	unsigned int MaxPlainTextLength(unsigned int cipherTextLength) const
		{return cipherTextLength < CipherTextLength(0) ? 0 : cipherTextLength - CipherTextLength(0);}
	unsigned int CipherTextLength(unsigned int plainTextLength) const
		{return plainTextLength + MAC::DIGESTSIZE + EncodedPointSize();}

	void Encrypt(RandomNumberGenerator &rng, const byte *plainText, unsigned int plainTextLength, byte *cipherText)
	{
		Integer x(rng, 1, m_n-1);
		Point Q = m_Gpc.Multiply(x);

		EncodePoint(cipherText, Q);
		cipherText += EncodedPointSize();

		SecByteBlock agreedSecret(FieldElementLength());
		Point Q1 = m_Qpc.Multiply(x);
		Q1.x.Encode(agreedSecret, agreedSecret.size);

		SecByteBlock derivedKey(plainTextLength + MAC::DEFAULT_KEYLENGTH);
		KDF::DeriveKey(derivedKey, derivedKey.size, agreedSecret, agreedSecret.size);
		xorbuf(cipherText, plainText, derivedKey, plainTextLength);

		MAC mac(derivedKey + plainTextLength);
		mac.CalculateDigest(cipherText + plainTextLength, cipherText, plainTextLength);
	}
};

/// Elliptic Curve ECIES, AKA <a href="http://www.weidai.com/scan-mirror/ca.html#/// Elliptic Curve ECIES, AKA <a href="http://www.weidai.com/scan-mirror/ca.html#EC-DHAES">EC-DHAES</a>
template <class EC, class MAC = HMAC<SHA>, class KDF = P1363_KDF2<SHA> >
class ECDecryptor : public ECPrivateKey<EC>, public PK_Decryptor
{
public:
	typedef typename EC::Point Point;
	
	EC_PRIVATE_KEY_CONSTRUCTORS(ECDecryptor, ECPrivateKey<EC>)

	unsigned int MaxPlainTextLength(unsigned int cipherTextLength) const
		{return cipherTextLength < CipherTextLength(0) ? 0 : cipherTextLength - CipherTextLength(0);}
	unsigned int CipherTextLength(unsigned int plainTextLength) const
		{return plainTextLength + MAC::DIGESTSIZE + EncodedPointSize();}

	unsigned int Decrypt(const byte *cipherText, unsigned int cipherTextLength, byte *plainText)
	{
		Point Q;
		if (!GetCurve().DecodePoint(Q, cipherText, EncodedPointSize()) || !GetCurve().VerifyPoint(Q) || Q.identity)
			return 0;
		cipherText += EncodedPointSize();

		const Integer e[2] = {m_n, m_d};
		Point R[2];
		GetCurve().SimultaneousMultiply(R, Q, e, 2);

		if (!R[0].identity || R[1].identity)
			return 0;

		SecByteBlock agreedSecret(FieldElementLength());
		R[1].x.Encode(agreedSecret, agreedSecret.size);

		unsigned int plainTextLength = MaxPlainTextLength(cipherTextLength);
		SecByteBlock derivedKey(plainTextLength + MAC::DEFAULT_KEYLENGTH);
		KDF::DeriveKey(derivedKey, derivedKey.size, agreedSecret, agreedSecret.size);
		
		MAC mac(derivedKey + plainTextLength);
		if (!mac.VerifyDigest(cipherText + plainTextLength, cipherText, plainTextLength))
			return 0;

		xorbuf(plainText, cipherText, derivedKey, plainTextLength);
		return plainTextLength;
	}
};

NAMESPACE_END

#endif