Golang packet.Signature类代码示例

func (d *dashEscaper) Close() (err error) {
	if !d.atBeginningOfLine {
		if err = d.buffered.WriteByte(lf); err != nil {
			return
		}
	}
	sig := new(packet.Signature)
	sig.SigType = packet.SigTypeText
	sig.PubKeyAlgo = d.privateKey.PubKeyAlgo
	sig.Hash = d.hashType
	sig.CreationTime = d.config.Now()
	sig.IssuerKeyId = &d.privateKey.KeyId

	if err = sig.Sign(d.h, d.privateKey, d.config); err != nil {
		return
	}

	out, err := armor.Encode(d.buffered, "PGP SIGNATURE", nil)
	if err != nil {
		return
	}

	if err = sig.Serialize(out); err != nil {
		return
	}
	if err = out.Close(); err != nil {
		return
	}
	if err = d.buffered.Flush(); err != nil {
		return
	}
	return
}

func detachSign(w io.Writer, signer *Entity, message io.Reader, sigType packet.SignatureType, config *packet.Config) (err error) {
	if signer.PrivateKey == nil {
		return errors.InvalidArgumentError("signing key doesn't have a private key")
	}
	if signer.PrivateKey.Encrypted {
		return errors.InvalidArgumentError("signing key is encrypted")
	}

	sig := new(packet.Signature)
	sig.SigType = sigType
	sig.PubKeyAlgo = signer.PrivateKey.PubKeyAlgo
	sig.Hash = config.Hash()
	sig.CreationTime = config.Now()
	sig.IssuerKeyId = &signer.PrivateKey.KeyId

	h, wrappedHash, err := hashForSignature(sig.Hash, sig.SigType)
	if err != nil {
		return
	}
	io.Copy(wrappedHash, message)

	err = sig.Sign(h, signer.PrivateKey, config)
	if err != nil {
		return
	}

	return sig.Serialize(w)
}

func signContent(content []byte, privKey *packet.PrivateKey) ([]byte, error) {
	sig := new(packet.Signature)
	sig.PubKeyAlgo = privKey.PubKeyAlgo
	sig.Hash = openpgpConfig.Hash()
	sig.CreationTime = time.Now()
	sig.IssuerKeyId = &privKey.KeyId

	h := openpgpConfig.Hash().New()
	h.Write(content)

	err := sig.Sign(h, privKey, openpgpConfig)
	if err != nil {
		return nil, err
	}

	buf := bytes.NewBufferString("openpgp ")
	// TODO: split the base64 blob over many lines for readability of the resulting file
	enc := base64.NewEncoder(base64.StdEncoding, buf)
	err = sig.Serialize(enc)
	if err != nil {
		return nil, err
	}
	enc.Close()

	return buf.Bytes(), nil
}

func (chks *checkSuite) TestCheckForgery(c *C) {
	trustedKey := testPrivKey0

	cfg := &asserts.DatabaseConfig{
		Backstore:      chks.bs,
		KeypairManager: asserts.NewMemoryKeypairManager(),
		TrustedKeys:    []*asserts.AccountKey{asserts.BootstrapAccountKeyForTest("canonical", &trustedKey.PublicKey)},
	}
	db, err := asserts.OpenDatabase(cfg)
	c.Assert(err, IsNil)

	encoded := asserts.Encode(chks.a)
	content, encodedSig := chks.a.Signature()
	// forgery
	forgedSig := new(packet.Signature)
	forgedSig.PubKeyAlgo = testPrivKey1.PubKeyAlgo
	forgedSig.Hash = crypto.SHA256
	forgedSig.CreationTime = time.Now()
	forgedSig.IssuerKeyId = &testPrivKey0.KeyId
	h := crypto.SHA256.New()
	h.Write(content)
	err = forgedSig.Sign(h, testPrivKey1, &packet.Config{DefaultHash: crypto.SHA256})
	c.Assert(err, IsNil)
	buf := new(bytes.Buffer)
	forgedSig.Serialize(buf)
	forgedSigEncoded := "openpgp " + base64.StdEncoding.EncodeToString(buf.Bytes())
	forgedEncoded := bytes.Replace(encoded, encodedSig, []byte(forgedSigEncoded), 1)
	c.Assert(forgedEncoded, Not(DeepEquals), encoded)

	forgedAssert, err := asserts.Decode(forgedEncoded)
	c.Assert(err, IsNil)

	err = db.Check(forgedAssert)
	c.Assert(err, ErrorMatches, "failed signature verification: .*")
}

func signContent(content []byte, privateKey PrivateKey) ([]byte, error) {
	opgPrivKey, ok := privateKey.(openpgpPrivateKey)
	if !ok {
		panic(fmt.Errorf("not an internally supported PrivateKey: %T", privateKey))
	}
	privKey := opgPrivKey.privk

	sig := new(packet.Signature)
	sig.PubKeyAlgo = privKey.PubKeyAlgo
	sig.Hash = openpgpConfig.Hash()
	sig.CreationTime = time.Now()
	sig.IssuerKeyId = &privKey.KeyId

	h := openpgpConfig.Hash().New()
	h.Write(content)

	err := sig.Sign(h, privKey, openpgpConfig)
	if err != nil {
		return nil, err
	}

	buf := new(bytes.Buffer)
	err = sig.Serialize(buf)
	if err != nil {
		return nil, err
	}

	return encodeFormatAndData("openpgp", buf.Bytes()), nil
}

// Given a control.Marshal'able object, encode it to the blobstore, while
// also doing a detached OpenPGP signature. The objects returned (in order)
// are data, commited to the blobstore, the signature for that object, commited
// to the blobstore, and any error(s), finally.
func (a Archive) encodeSigned(data interface{}) (*blobstore.Object, *blobstore.Object, error) {
	/* Right, so, the trick here is that we secretly call out to encode,
	 * but tap it with a pipe into the signing code */

	if a.signingKey == nil {
		return nil, nil, fmt.Errorf("No signing key loaded")
	}

	signature, err := a.Store.Create()
	if err != nil {
		return nil, nil, err
	}
	defer signature.Close()

	hash := sha512.New()

	obj, err := a.encode(data, hash)
	if err != nil {
		return nil, nil, err
	}

	sig := new(packet.Signature)
	sig.SigType = packet.SigTypeBinary
	sig.PubKeyAlgo = a.signingKey.PrivateKey.PubKeyAlgo

	sig.Hash = crypto.SHA512

	sig.CreationTime = new(packet.Config).Now()
	sig.IssuerKeyId = &(a.signingKey.PrivateKey.KeyId)

	err = sig.Sign(hash, a.signingKey.PrivateKey, &packet.Config{
		DefaultHash: crypto.SHA512,
	})

	if err != nil {
		return nil, nil, err
	}

	if err := sig.Serialize(signature); err != nil {
		return nil, nil, err
	}

	sigObj, err := a.Store.Commit(*signature)
	if err != nil {
		return nil, nil, err
	}

	return obj, sigObj, nil

}

func (chks *checkSuite) TestCheckForgery(c *C) {
	trustedKey := testPrivKey0

	cfg := &asserts.DatabaseConfig{
		Backstore: chks.bs,
		Trusted:   []asserts.Assertion{asserts.BootstrapAccountKeyForTest("canonical", trustedKey.PublicKey())},
	}
	db, err := asserts.OpenDatabase(cfg)
	c.Assert(err, IsNil)

	encoded := asserts.Encode(chks.a)
	content, encodedSig := chks.a.Signature()
	// forgery
	forgedSig := new(packet.Signature)
	forgedSig.PubKeyAlgo = packet.PubKeyAlgoRSA
	forgedSig.Hash = crypto.SHA512
	forgedSig.CreationTime = time.Now()
	h := crypto.SHA512.New()
	h.Write(content)
	pk1 := packet.NewRSAPrivateKey(time.Unix(1, 0), testPrivKey1RSA)
	err = forgedSig.Sign(h, pk1, &packet.Config{DefaultHash: crypto.SHA512})
	c.Assert(err, IsNil)
	buf := new(bytes.Buffer)
	forgedSig.Serialize(buf)
	b := append([]byte{0x1}, buf.Bytes()...)
	forgedSigEncoded := base64.StdEncoding.EncodeToString(b)
	forgedEncoded := bytes.Replace(encoded, encodedSig, []byte(forgedSigEncoded), 1)
	c.Assert(forgedEncoded, Not(DeepEquals), encoded)

	forgedAssert, err := asserts.Decode(forgedEncoded)
	c.Assert(err, IsNil)

	err = db.Check(forgedAssert)
	c.Assert(err, ErrorMatches, "failed signature verification: .*")
}

func (opgPrivK openpgpPrivateKey) sign(content []byte) (*packet.Signature, error) {
	privk := opgPrivK.privk
	sig := new(packet.Signature)
	sig.PubKeyAlgo = privk.PubKeyAlgo
	sig.Hash = openpgpConfig.Hash()
	sig.CreationTime = time.Now()

	h := openpgpConfig.Hash().New()
	h.Write(content)

	err := sig.Sign(h, privk, openpgpConfig)
	if err != nil {
		return nil, err
	}

	return sig, nil
}

func (gkms *gpgKeypairMgrSuite) TestUseInSigningBrokenSignature(c *C) {
	_, rsaPrivKey := assertstest.ReadPrivKey(assertstest.DevKey)
	pgpPrivKey := packet.NewRSAPrivateKey(time.Unix(1, 0), rsaPrivKey)

	var breakSig func(sig *packet.Signature, cont []byte) []byte

	mockGPG := func(prev asserts.GPGRunner, input []byte, args ...string) ([]byte, error) {
		if args[1] == "--list-secret-keys" || args[1] == "--export" {
			return prev(input, args...)
		}
		n := len(args)
		c.Assert(args[n-1], Equals, "--detach-sign")

		sig := new(packet.Signature)
		sig.PubKeyAlgo = packet.PubKeyAlgoRSA
		sig.Hash = crypto.SHA512
		sig.CreationTime = time.Now()

		// poking to break the signature
		cont := breakSig(sig, input)

		h := sig.Hash.New()
		h.Write([]byte(cont))

		err := sig.Sign(h, pgpPrivKey, nil)
		c.Assert(err, IsNil)

		buf := new(bytes.Buffer)
		sig.Serialize(buf)
		return buf.Bytes(), nil
	}
	restore := asserts.MockRunGPG(mockGPG)
	defer restore()

	signDB, err := asserts.OpenDatabase(&asserts.DatabaseConfig{
		KeypairManager: gkms.keypairMgr,
	})
	c.Assert(err, IsNil)

	headers := map[string]interface{}{
		"authority-id":  "dev1-id",
		"snap-sha3-384": blobSHA3_384,
		"snap-id":       "snap-id-1",
		"grade":         "devel",
		"snap-size":     "1025",
		"timestamp":     time.Now().Format(time.RFC3339),
	}

	tests := []struct {
		breakSig    func(*packet.Signature, []byte) []byte
		expectedErr string
	}{
		{func(sig *packet.Signature, cont []byte) []byte {
			sig.Hash = crypto.SHA1
			return cont
		}, "cannot sign assertion: bad GPG produced signature: expected SHA512 digest"},
		{func(sig *packet.Signature, cont []byte) []byte {
			return cont[:5]
		}, "cannot sign assertion: bad GPG produced signature: it does not verify:.*"},
	}

	for _, t := range tests {
		breakSig = t.breakSig

		_, err = signDB.Sign(asserts.SnapBuildType, headers, nil, assertstest.DevKeyID)
		c.Check(err, ErrorMatches, t.expectedErr)
	}

}