Golang asn1.Marshal类(方法)实例源码

// MarshalPKIXPublicKey serialises a public key to DER-encoded PKIX format.
func MarshalPKIXPublicKey(pub interface{}) ([]byte, os.Error) {
	var pubBytes []byte

	switch pub := pub.(type) {
	case *rsa.PublicKey:
		pubBytes, _ = asn1.Marshal(rsaPublicKey{
			N: pub.N,
			E: pub.E,
		})
	default:
		return nil, os.NewError("MarshalPKIXPublicKey: unknown public key type")
	}

	pkix := pkixPublicKey{
		Algo: pkix.AlgorithmIdentifier{
			Algorithm: []int{1, 2, 840, 113549, 1, 1, 1},
			// This is a NULL parameters value which is technically
			// superfluous, but most other code includes it and, by
			// doing this, we match their public key hashes.
			Parameters: asn1.RawValue{
				Tag: 5,
			},
		},
		BitString: asn1.BitString{
			Bytes:     pubBytes,
			BitLength: 8 * len(pubBytes),
		},
	}

	ret, _ := asn1.Marshal(pkix)
	return ret, nil
}

// CreateCRL returns a DER encoded CRL, signed by this Certificate, that
// contains the given list of revoked certificates.
func (c *Certificate) CreateCRL(rand io.Reader, priv *rsa.PrivateKey, revokedCerts []pkix.RevokedCertificate, now, expiry *time.Time) (crlBytes []byte, err os.Error) {
	tbsCertList := pkix.TBSCertificateList{
		Version: 2,
		Signature: pkix.AlgorithmIdentifier{
			Algorithm: oidSignatureSHA1WithRSA,
		},
		Issuer:              c.Subject.ToRDNSequence(),
		ThisUpdate:          now,
		NextUpdate:          expiry,
		RevokedCertificates: revokedCerts,
	}

	tbsCertListContents, err := asn1.Marshal(tbsCertList)
	if err != nil {
		return
	}

	h := sha1.New()
	h.Write(tbsCertListContents)
	digest := h.Sum()

	signature, err := rsa.SignPKCS1v15(rand, priv, crypto.SHA1, digest)
	if err != nil {
		return
	}

	return asn1.Marshal(pkix.CertificateList{
		TBSCertList: tbsCertList,
		SignatureAlgorithm: pkix.AlgorithmIdentifier{
			Algorithm: oidSignatureSHA1WithRSA,
		},
		SignatureValue: asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
	})
}

func GetStringValue(oid asn1.ObjectIdentifier, community string, addr net.UDPAddr) (string, os.Error) {
	conn, err := net.DialUDP("udp", nil, &addr)
	if err != nil {
		return "", err
	}
	defer conn.Close()

	r := PDU{
		RequestId:   199,
		ErrorStatus: 0,
		ErrorIndex:  0,
		VarBindList: []VarBind{
			VarBind{
				Name:  oid,
				Value: Null(),
			},
		},
	}

	data, err := asn1.Marshal(r)
	if err != nil {
		return "", err
	}

	m := Message{
		Version:   1,
		Community: NewOctetString(community),
		Data:      Any(data),
	}

	data, err = asn1.Marshal(m)
	if err != nil {
		return "", err
	}

	_, err = conn.Write(data)
	if err != nil {
		return "", err
	}

	data = make([]byte, 1500)
	read, err := conn.Read(data)
	if err != nil {
		return "", err
	}

	pdu, err := decode(data[:read])
	if err != nil {
		return "", err
	}
	switch response := pdu.(type) {
	case *PDU:
		s, ok := response.VarBindList[0].Value.([]byte)
		if !ok {
			return "", fmt.Errorf("Invalid value returned")
		}
		return string(s), nil
	}
	return "", nil
}

// CreateSelfSignedCertificate creates a new certificate based on
// a template. The following members of template are used: SerialNumber,
// Subject, NotBefore, NotAfter, KeyUsage, BasicConstraintsValid, IsCA,
// MaxPathLen, SubjectKeyId, DNSNames, PermittedDNSDomainsCritical,
// PermittedDNSDomains.
//
// The certificate is signed by parent. If parent is equal to template then the
// certificate is self-signed. The parameter pub is the public key of the
// signee and priv is the private key of the signer.
//
// The returned slice is the certificate in DER encoding.
func CreateCertificate(rand io.Reader, template, parent *Certificate, pub *rsa.PublicKey, priv *rsa.PrivateKey) (cert []byte, err os.Error) {
	asn1PublicKey, err := asn1.Marshal(rsaPublicKey{
		N: asn1.RawValue{Tag: 2, Bytes: pub.N.Bytes()},
		E: pub.E,
	})
	if err != nil {
		return
	}

	if len(parent.SubjectKeyId) > 0 {
		template.AuthorityKeyId = parent.SubjectKeyId
	}

	extensions, err := buildExtensions(template)
	if err != nil {
		return
	}

	encodedPublicKey := asn1.BitString{BitLength: len(asn1PublicKey) * 8, Bytes: asn1PublicKey}
	c := tbsCertificate{
		Version:            2,
		SerialNumber:       asn1.RawValue{Bytes: template.SerialNumber, Tag: 2},
		SignatureAlgorithm: algorithmIdentifier{Algorithm: oidSHA1WithRSA},
		Issuer:             parent.Subject.toRDNSequence(),
		Validity:           validity{template.NotBefore, template.NotAfter},
		Subject:            template.Subject.toRDNSequence(),
		PublicKey:          publicKeyInfo{nil, algorithmIdentifier{Algorithm: oidRSA}, encodedPublicKey},
		Extensions:         extensions,
	}

	tbsCertContents, err := asn1.Marshal(c)
	if err != nil {
		return
	}

	c.Raw = tbsCertContents

	h := sha1.New()
	h.Write(tbsCertContents)
	digest := h.Sum()

	signature, err := rsa.SignPKCS1v15(rand, priv, crypto.SHA1, digest)
	if err != nil {
		return
	}

	cert, err = asn1.Marshal(certificate{
		nil,
		c,
		algorithmIdentifier{Algorithm: oidSHA1WithRSA},
		asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
	})
	return
}

// MarshalPKCS1PrivateKey converts a private key to ASN.1 DER encoded form.
func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte {
	key.Precompute()

	version := 0
	if len(key.Primes) > 2 {
		version = 1
	}

	priv := pkcs1PrivateKey{
		Version: version,
		N:       key.N,
		E:       key.PublicKey.E,
		D:       key.D,
		P:       key.Primes[0],
		Q:       key.Primes[1],
		Dp:      key.Precomputed.Dp,
		Dq:      key.Precomputed.Dq,
		Qinv:    key.Precomputed.Qinv,
	}

	priv.AdditionalPrimes = make([]pkcs1AdditionalRSAPrime, len(key.Precomputed.CRTValues))
	for i, values := range key.Precomputed.CRTValues {
		priv.AdditionalPrimes[i].Prime = key.Primes[2+i]
		priv.AdditionalPrimes[i].Exp = values.Exp
		priv.AdditionalPrimes[i].Coeff = values.Coeff
	}

	b, _ := asn1.Marshal(priv)
	return b
}

// MarshalPKCS1PrivateKey converts a private key to ASN.1 DER encoded form.
func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte {
	key.Precompute()

	version := 0
	if len(key.Primes) > 2 {
		version = 1
	}

	priv := pkcs1PrivateKey{
		Version: version,
		N:       rawValueForBig(key.N),
		E:       key.PublicKey.E,
		D:       rawValueForBig(key.D),
		P:       rawValueForBig(key.Primes[0]),
		Q:       rawValueForBig(key.Primes[1]),
		Dp:      rawValueForBig(key.Precomputed.Dp),
		Dq:      rawValueForBig(key.Precomputed.Dq),
		Qinv:    rawValueForBig(key.Precomputed.Qinv),
	}

	priv.AdditionalPrimes = make([]pkcs1AdditionalRSAPrime, len(key.Precomputed.CRTValues))
	for i, values := range key.Precomputed.CRTValues {
		priv.AdditionalPrimes[i].Prime = rawValueForBig(key.Primes[2+i])
		priv.AdditionalPrimes[i].Exp = rawValueForBig(values.Exp)
		priv.AdditionalPrimes[i].Coeff = rawValueForBig(values.Coeff)
	}

	b, _ := asn1.Marshal(priv)
	return b
}

func TestSNMPGetNextRequest(t *testing.T) {
	r := PDU{
		RequestId:   199,
		ErrorStatus: 0,
		ErrorIndex:  0,
		VarBindList: []VarBind{
			VarBind{
				Name:  []int{1, 3, 6, 1, 2, 1, 1, 1, 0},
				Value: Null(),
			},
		},
	}

	data, err := asn1.Marshal(r)
	if err != nil {
		t.Error(err)
	}

	m := Message{
		Version:   1,
		Community: NewOctetString("timer"),
		Data:      Any(data),
	}

	data, err = asn1.Marshal(m)
	if err != nil {
		t.Error(err)
	}

	addr := net.UDPAddr{net.IPv4(192, 168, 1, 254), 161}
	conn, err := net.DialUDP("udp4", nil, &addr)
	if err != nil {
		t.Error(err)
	}
	defer conn.Close()

	written, err := conn.Write(data)
	if err != nil {
		t.Error(err)
	}

	if written != len(data) {
		t.Errorf("did not write the full data %d", written)
	}

}

// MarshalPKCS1PrivateKey converts a private key to ASN.1 DER encoded form.
func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte {
	priv := pkcs1PrivateKey{
		Version: 1,
		N:       asn1.RawValue{Tag: 2, Bytes: key.PublicKey.N.Bytes()},
		E:       key.PublicKey.E,
		D:       asn1.RawValue{Tag: 2, Bytes: key.D.Bytes()},
		P:       asn1.RawValue{Tag: 2, Bytes: key.P.Bytes()},
		Q:       asn1.RawValue{Tag: 2, Bytes: key.Q.Bytes()},
	}

	b, _ := asn1.Marshal(priv)
	return b
}

func buildExtensions(template *Certificate) (ret []extension, err os.Error) {
	ret = make([]extension, 6 /* maximum number of elements. */)
	n := 0

	if template.KeyUsage != 0 {
		ret[n].Id = oidExtensionKeyUsage
		ret[n].Critical = true

		var a [2]byte
		a[0] = reverseBitsInAByte(byte(template.KeyUsage))
		a[1] = reverseBitsInAByte(byte(template.KeyUsage >> 8))

		l := 1
		if a[1] != 0 {
			l = 2
		}

		ret[n].Value, err = asn1.Marshal(asn1.BitString{Bytes: a[0:l], BitLength: l * 8})
		if err != nil {
			return
		}
		n++
	}

	if template.BasicConstraintsValid {
		ret[n].Id = oidExtensionBasicConstraints
		ret[n].Value, err = asn1.Marshal(basicConstraints{template.IsCA, template.MaxPathLen})
		ret[n].Critical = true
		if err != nil {
			return
		}
		n++
	}

	if len(template.SubjectKeyId) > 0 {
		ret[n].Id = oidExtensionSubjectKeyId
		ret[n].Value, err = asn1.Marshal(template.SubjectKeyId)
		if err != nil {
			return
		}
		n++
	}

	if len(template.AuthorityKeyId) > 0 {
		ret[n].Id = oidExtensionAuthorityKeyId
		ret[n].Value, err = asn1.Marshal(authKeyId{template.AuthorityKeyId})
		if err != nil {
			return
		}
		n++
	}

	if len(template.DNSNames) > 0 {
		ret[n].Id = oidExtensionSubjectAltName
		rawValues := make([]asn1.RawValue, len(template.DNSNames))
		for i, name := range template.DNSNames {
			rawValues[i] = asn1.RawValue{Tag: 2, Class: 2, Bytes: []byte(name)}
		}
		ret[n].Value, err = asn1.Marshal(rawValues)
		if err != nil {
			return
		}
		n++
	}

	if len(template.PolicyIdentifiers) > 0 {
		ret[n].Id = oidExtensionCertificatePolicies
		policies := make([]policyInformation, len(template.PolicyIdentifiers))
		for i, policy := range template.PolicyIdentifiers {
			policies[i].Policy = policy
		}
		ret[n].Value, err = asn1.Marshal(policies)
		if err != nil {
			return
		}
		n++
	}

	// Adding another extension here? Remember to update the maximum number
	// of elements in the make() at the top of the function.

	return ret[0:n], nil
}