Golang Suite.Read方法代码示例

func SchnorrVerify(suite abstract.Suite, message []byte, publicKey abstract.Point,
	signatureBuffer []byte) error {

	// Decode the signature
	buf := bytes.NewBuffer(signatureBuffer)
	sig := basicSig{}
	if err := suite.Read(buf, &sig); err != nil {
		return err
	}
	r := sig.R
	c := sig.C

	// Compute base**(r + x*c) == T
	var P, T abstract.Point
	P = suite.Point()
	T = suite.Point()
	T.Add(T.Mul(nil, r), P.Mul(publicKey, c))

	// Verify that the hash based on the message and T
	// matches the challange c from the signature
	c = hashSchnorr(suite, message, T)
	if !c.Equal(sig.C) {
		return errors.New("invalid signature")
	}

	return nil
}

// Verify checks a signature generated by Sign.
//
// The caller provides the message, anonymity set, and linkage scope
// with which the signature was purportedly produced.
// If the signature is a valid linkable signature (linkScope != nil),
// this function returns a linkage tag that uniquely corresponds
// to the signer within the given linkScope.
// If the signature is a valid unlinkable signature (linkScope == nil),
// returns an empty but non-nil byte-slice instead of a linkage tag on success.
// Returns a nil linkage tag and an error if the signature is invalid.
func Verify(suite abstract.Suite, message []byte, anonymitySet Set,
	linkScope []byte, signatureBuffer []byte) ([]byte, error) {

	n := len(anonymitySet)              // anonymity set size
	L := []abstract.Point(anonymitySet) // public keys in ring

	// Decode the signature
	buf := bytes.NewBuffer(signatureBuffer)
	var linkBase, linkTag abstract.Point
	sig := lSig{}
	sig.S = make([]abstract.Secret, n)
	if linkScope != nil { // linkable ring signature
		if err := suite.Read(buf, &sig); err != nil {
			return nil, err
		}
		linkStream := suite.Cipher(linkScope)
		linkBase, _ = suite.Point().Pick(nil, linkStream)
		linkTag = sig.Tag
	} else { // unlinkable ring signature
		if err := suite.Read(buf, &sig.uSig); err != nil {
			return nil, err
		}
	}

	// Pre-hash the ring-position-invariant parameters to H1.
	H1pre := signH1pre(suite, linkScope, linkTag, message)

	// Verify the signature
	var P, PG, PH abstract.Point
	P = suite.Point()
	PG = suite.Point()
	if linkScope != nil {
		PH = suite.Point()
	}
	s := sig.S
	ci := sig.C0
	for i := 0; i < n; i++ {
		PG.Add(PG.Mul(nil, s[i]), P.Mul(L[i], ci))
		if linkScope != nil {
			PH.Add(PH.Mul(linkBase, s[i]), P.Mul(linkTag, ci))
		}
		ci = signH1(suite, H1pre, PG, PH)
	}
	if !ci.Equal(sig.C0) {
		return nil, errors.New("invalid signature")
	}

	// Return the re-encoded linkage tag, for uniqueness checking
	if linkScope != nil {
		tag, _ := linkTag.MarshalBinary()
		return tag, nil
	} else {
		return []byte{}, nil
	}
}

// ReadPrivKey will read the file and decrypt the private key inside
// It takes a suite to decrypt and a filename to know where to read
// Returns the secret and an error if anything wrong occured
func ReadPrivKey(suite abstract.Suite, fileName string) (abstract.Secret, error) {
	secret := suite.Secret()
	// Opening files
	privFile, err := os.Open(fileName)
	if err != nil {
		return nil, err
	}
	defer privFile.Close()

	// Read the keys
	err = suite.Read(privFile, &secret)
	if err != nil {
		return nil, err
	}
	return secret, nil
}

// ReadScalar64 takes a Base64-encoded scalar and returns that scalar,
// optionally an error
func ReadScalar64(suite abstract.Suite, r io.Reader) (abstract.Scalar, error) {
	s := suite.Scalar()
	dec := base64.NewDecoder(base64.StdEncoding, r)
	err := suite.Read(dec, &s)
	return s, err
}

// ReadPub64 a public point to a base64 representation
func ReadPub64(suite abstract.Suite, r io.Reader) (abstract.Point, error) {
	public := suite.Point()
	dec := base64.NewDecoder(base64.StdEncoding, r)
	err := suite.Read(dec, &public)
	return public, err
}

func ReadSecret64(suite abstract.Suite, r io.Reader) (abstract.Secret, error) {
	sec := suite.Secret()
	dec := base64.NewDecoder(base64.StdEncoding, r)
	err := suite.Read(dec, &sec)
	return sec, err
}