// UnmarshalJSON populates a new SignedManifest struct from JSON data.
func (sm *SignedManifest) UnmarshalJSON(b []byte) error {
	sm.all = make([]byte, len(b), len(b))
	// store manifest and signatures in all
	copy(sm.all, b)

	jsig, err := libtrust.ParsePrettySignature(b, "signatures")
	if err != nil {
		return err
	}

	// Resolve the payload in the manifest.
	bytes, err := jsig.Payload()
	if err != nil {
		return err
	}

	// sm.Canonical stores the canonical manifest JSON
	sm.Canonical = make([]byte, len(bytes), len(bytes))
	copy(sm.Canonical, bytes)

	// Unmarshal canonical JSON into Manifest object
	var manifest Manifest
	if err := json.Unmarshal(sm.Canonical, &manifest); err != nil {
		return err
	}

	sm.Manifest = manifest

	return nil
}

// LoadStatement loads and verifies a statement from an input stream.
func LoadStatement(r io.Reader, authority *x509.CertPool) (*Statement, error) {
	b, err := ioutil.ReadAll(r)
	if err != nil {
		return nil, err
	}
	js, err := libtrust.ParsePrettySignature(b, "signatures")
	if err != nil {
		return nil, err
	}
	payload, err := js.Payload()
	if err != nil {
		return nil, err
	}
	var statement Statement
	err = json.Unmarshal(payload, &statement.jsonStatement)
	if err != nil {
		return nil, err
	}

	if authority == nil {
		_, err = js.Verify()
		if err != nil {
			return nil, err
		}
	} else {
		_, err = js.VerifyChains(authority)
		if err != nil {
			return nil, err
		}
	}
	statement.signature = js

	return &statement, nil
}

// VerifyChains verifies the signature of the signed manifest against the
// certificate pool returning the list of verified chains. Signatures without
// an x509 chain are not checked.
func VerifyChains(sm *SignedManifest, ca *x509.CertPool) ([][]*x509.Certificate, error) {
	js, err := libtrust.ParsePrettySignature(sm.Raw, "signatures")
	if err != nil {
		return nil, err
	}

	return js.VerifyChains(ca)
}

func Payload(data []byte) ([]byte, error) {
	jsig, err := libtrust.ParsePrettySignature(data, "signatures")
	if err != nil {
		return nil, err
	}

	// Resolve the payload in the manifest.
	return jsig.Payload()
}

// Verify verifies the signature of the signed manifest returning the public
// keys used during signing.
func Verify(sm *SignedManifest) ([]libtrust.PublicKey, error) {
	js, err := libtrust.ParsePrettySignature(sm.Raw, "signatures")
	if err != nil {
		logrus.WithField("err", err).Debugf("(*SignedManifest).Verify")
		return nil, err
	}

	return js.Verify()
}

// Signatures returns the signatures as provided by
// (*libtrust.JSONSignature).Signatures. The byte slices are opaque jws
// signatures.
func (sm *SignedManifest) Signatures() ([][]byte, error) {
	jsig, err := libtrust.ParsePrettySignature(sm.Raw, "signatures")
	if err != nil {
		return nil, err
	}

	// Resolve the payload in the manifest.
	return jsig.Signatures()
}

// loadManifest loads a manifest from a byte array and verifies its content.
// The signature must be verified or an error is returned. If the manifest
// contains no signatures by a trusted key for the name in the manifest, the
// image is not considered verified. The parsed manifest object and a boolean
// for whether the manifest is verified is returned.
func (s *TagStore) loadManifest(eng *engine.Engine, manifestBytes []byte) (*registry.ManifestData, bool, error) {
	sig, err := libtrust.ParsePrettySignature(manifestBytes, "signatures")
	if err != nil {
		return nil, false, fmt.Errorf("error parsing payload: %s", err)
	}

	keys, err := sig.Verify()
	if err != nil {
		return nil, false, fmt.Errorf("error verifying payload: %s", err)
	}

	payload, err := sig.Payload()
	if err != nil {
		return nil, false, fmt.Errorf("error retrieving payload: %s", err)
	}

	var manifest registry.ManifestData
	if err := json.Unmarshal(payload, &manifest); err != nil {
		return nil, false, fmt.Errorf("error unmarshalling manifest: %s", err)
	}
	if manifest.SchemaVersion != 1 {
		return nil, false, fmt.Errorf("unsupported schema version: %d", manifest.SchemaVersion)
	}

	var verified bool
	for _, key := range keys {
		job := eng.Job("trust_key_check")
		b, err := key.MarshalJSON()
		if err != nil {
			return nil, false, fmt.Errorf("error marshalling public key: %s", err)
		}
		namespace := manifest.Name
		if namespace[0] != '/' {
			namespace = "/" + namespace
		}
		stdoutBuffer := bytes.NewBuffer(nil)

		job.Args = append(job.Args, namespace)
		job.Setenv("PublicKey", string(b))
		// Check key has read/write permission (0x03)
		job.SetenvInt("Permission", 0x03)
		job.Stdout.Add(stdoutBuffer)
		if err = job.Run(); err != nil {
			return nil, false, fmt.Errorf("error running key check: %s", err)
		}
		result := engine.Tail(stdoutBuffer, 1)
		log.Debugf("Key check result: %q", result)
		if result == "verified" {
			verified = true
		}
	}

	return &manifest, verified, nil
}

// signedManifestFromImage converts an Image to a SignedManifest.
func (r *repository) signedManifestFromImage(image *imageapi.Image) (*schema1.SignedManifest, error) {
	if image.DockerImageManifestMediaType == schema2.MediaTypeManifest {
		context.GetLogger(r.ctx).Errorf("old client pulling new image %s", image.DockerImageReference)
		return nil, fmt.Errorf("unable to convert new image to old one")
	}

	raw := []byte(image.DockerImageManifest)
	// prefer signatures from the manifest
	if _, err := libtrust.ParsePrettySignature(raw, "signatures"); err == nil {
		sm := schema1.SignedManifest{Canonical: raw}
		if err = json.Unmarshal(raw, &sm); err == nil {
			return &sm, nil
		}
	}

	dgst, err := digest.ParseDigest(image.Name)
	if err != nil {
		return nil, err
	}

	var signBytes [][]byte
	if len(image.DockerImageSignatures) == 0 {
		// Fetch the signatures for the manifest
		signatures, errSign := r.getSignatures(dgst)
		if errSign != nil {
			return nil, errSign
		}

		for _, signatureDigest := range signatures {
			signBytes = append(signBytes, []byte(signatureDigest))
		}
	} else {
		for _, sign := range image.DockerImageSignatures {
			signBytes = append(signBytes, sign)
		}
	}

	jsig, err := libtrust.NewJSONSignature(raw, signBytes...)
	if err != nil {
		return nil, err
	}

	// Extract the pretty JWS
	raw, err = jsig.PrettySignature("signatures")
	if err != nil {
		return nil, err
	}

	var sm schema1.SignedManifest
	if err = json.Unmarshal(raw, &sm); err != nil {
		return nil, err
	}
	return &sm, err
}

// Digest returns the a digest of a docker manifest, with any necessary implied transformations like stripping v1s1 signatures.
func Digest(manifest []byte) (digest.Digest, error) {
	if GuessMIMEType(manifest) == DockerV2Schema1SignedMediaType {
		sig, err := libtrust.ParsePrettySignature(manifest, "signatures")
		if err != nil {
			return "", err
		}
		manifest, err = sig.Payload()
		if err != nil {
			// Coverage: This should never happen, libtrust's Payload() can fail only if joseBase64UrlDecode() fails, on a string
			// that libtrust itself has josebase64UrlEncode()d
			return "", err
		}
	}

	return digest.FromBytes(manifest), nil
}

// Digest returns the a digest of a docker manifest, with any necessary implied transformations like stripping v1s1 signatures.
func Digest(manifest []byte) (string, error) {
	if GuessMIMEType(manifest) == DockerV2Schema1SignedMIMEType {
		sig, err := libtrust.ParsePrettySignature(manifest, "signatures")
		if err != nil {
			return "", err
		}
		manifest, err = sig.Payload()
		if err != nil {
			// Coverage: This should never happen, libtrust's Payload() can fail only if joseBase64UrlDecode() fails, on a string
			// that libtrust itself has josebase64UrlEncode()d
			return "", err
		}
	}

	hash := sha256.Sum256(manifest)
	return "sha256:" + hex.EncodeToString(hash[:]), nil
}

func getManifestDigest(content []byte) (string, error) {
	jsonSig, err := libtrust.ParsePrettySignature(content, "signatures")
	if err != nil {
		return "", err
	}

	// Resolve the payload in the manifest.
	bytes, err := jsonSig.Payload()
	if err != nil {
		return "", err
	}

	log.Debugf("Canonical Bytes: %d", len(bytes))
	digest := ddigest.FromBytes(bytes)
	// Correct Manifest Digest
	log.Debugf("Manifest Digest: %v", digest)
	return string(digest), nil
}

// unpackSignedManifest takes the raw, signed manifest bytes, unpacks the jws
// and returns the payload and public keys used to signed the manifest.
// Signatures are verified for authenticity but not against the trust store.
func unpackSignedManifest(p []byte) ([]byte, []libtrust.PublicKey, error) {
	sig, err := libtrust.ParsePrettySignature(p, "signatures")
	if err != nil {
		return nil, nil, fmt.Errorf("error parsing payload: %s", err)
	}

	keys, err := sig.Verify()
	if err != nil {
		return nil, nil, fmt.Errorf("error verifying payload: %s", err)
	}

	payload, err := sig.Payload()
	if err != nil {
		return nil, nil, fmt.Errorf("error retrieving payload: %s", err)
	}

	return payload, keys, nil
}

// manifestFromImage converts an Image to a SignedManifest.
func (r *repository) manifestFromImage(image *imageapi.Image) (*schema1.SignedManifest, error) {
	dgst, err := digest.ParseDigest(image.Name)
	if err != nil {
		return nil, err
	}

	raw := []byte(image.DockerImageManifest)

	// prefer signatures from the manifest
	if _, err := libtrust.ParsePrettySignature(raw, "signatures"); err == nil {
		sm := schema1.SignedManifest{Raw: raw}
		if err := json.Unmarshal(raw, &sm); err == nil {
			return &sm, nil
		}
	}

	// Fetch the signatures for the manifest
	signatures, err := r.Signatures().Get(dgst)
	if err != nil {
		return nil, err
	}

	jsig, err := libtrust.NewJSONSignature(raw, signatures...)
	if err != nil {
		return nil, err
	}

	// Extract the pretty JWS
	raw, err = jsig.PrettySignature("signatures")
	if err != nil {
		return nil, err
	}

	var sm schema1.SignedManifest
	if err := json.Unmarshal(raw, &sm); err != nil {
		return nil, err
	}
	return &sm, err
}

//.........这里部分代码省略.........

		if _, err := io.Copy(wr, rs); err != nil {
			t.Fatalf("unexpected error copying to upload: %v", err)
		}

		if _, err := wr.Commit(env.ctx, distribution.Descriptor{Digest: dgst}); err != nil {
			t.Fatalf("unexpected error finishing upload: %v", err)
		}
	}

	if err = ms.Put(sm); err != nil {
		t.Fatalf("unexpected error putting manifest: %v", err)
	}

	exists, err = ms.ExistsByTag(env.tag)
	if err != nil {
		t.Fatalf("unexpected error checking manifest existence: %v", err)
	}

	if !exists {
		t.Fatalf("manifest should exist")
	}

	fetchedManifest, err := ms.GetByTag(env.tag)

	if err != nil {
		t.Fatalf("unexpected error fetching manifest: %v", err)
	}

	if !reflect.DeepEqual(fetchedManifest, sm) {
		t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedManifest, sm)
	}

	fetchedJWS, err := libtrust.ParsePrettySignature(fetchedManifest.Raw, "signatures")
	if err != nil {
		t.Fatalf("unexpected error parsing jws: %v", err)
	}

	payload, err := fetchedJWS.Payload()
	if err != nil {
		t.Fatalf("unexpected error extracting payload: %v", err)
	}

	// Now that we have a payload, take a moment to check that the manifest is
	// return by the payload digest.
	dgst, err := digest.FromBytes(payload)
	if err != nil {
		t.Fatalf("error getting manifest digest: %v", err)
	}

	exists, err = ms.Exists(dgst)
	if err != nil {
		t.Fatalf("error checking manifest existence by digest: %v", err)
	}

	if !exists {
		t.Fatalf("manifest %s should exist", dgst)
	}

	fetchedByDigest, err := ms.Get(dgst)
	if err != nil {
		t.Fatalf("unexpected error fetching manifest by digest: %v", err)
	}

	if !reflect.DeepEqual(fetchedByDigest, fetchedManifest) {
		t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedByDigest, fetchedManifest)

//.........这里部分代码省略.........
	if err != nil {
		t.Fatalf("unexpected error checking manifest existence: %#v", err)
	}

	if !exists {
		t.Fatalf("manifest should exist")
	}

	fromStore, err := ms.Get(ctx, manifestDigest)
	if err != nil {
		t.Fatalf("unexpected error fetching manifest: %v", err)
	}

	fetchedManifest, ok := fromStore.(*schema1.SignedManifest)
	if !ok {
		t.Fatalf("unexpected manifest type from signedstore")
	}

	if !bytes.Equal(fetchedManifest.Canonical, sm.Canonical) {
		t.Fatalf("fetched payload does not match original payload: %q != %q", fetchedManifest.Canonical, sm.Canonical)
	}

	if equalSignatures {
		if !reflect.DeepEqual(fetchedManifest, sm) {
			t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedManifest.Manifest, sm.Manifest)
		}
	}

	_, pl, err := fetchedManifest.Payload()
	if err != nil {
		t.Fatalf("error getting payload %#v", err)
	}

	fetchedJWS, err := libtrust.ParsePrettySignature(pl, "signatures")
	if err != nil {
		t.Fatalf("unexpected error parsing jws: %v", err)
	}

	payload, err := fetchedJWS.Payload()
	if err != nil {
		t.Fatalf("unexpected error extracting payload: %v", err)
	}

	// Now that we have a payload, take a moment to check that the manifest is
	// return by the payload digest.

	dgst := digest.FromBytes(payload)
	exists, err = ms.Exists(ctx, dgst)
	if err != nil {
		t.Fatalf("error checking manifest existence by digest: %v", err)
	}

	if !exists {
		t.Fatalf("manifest %s should exist", dgst)
	}

	fetchedByDigest, err := ms.Get(ctx, dgst)
	if err != nil {
		t.Fatalf("unexpected error fetching manifest by digest: %v", err)
	}

	byDigestManifest, ok := fetchedByDigest.(*schema1.SignedManifest)
	if !ok {
		t.Fatalf("unexpected manifest type from signedstore")
	}

//.........这里部分代码省略.........
		}

		if _, err := io.Copy(upload, rs); err != nil {
			t.Fatalf("unexpected error copying to upload: %v", err)
		}

		if _, err := upload.Finish(dgst); err != nil {
			t.Fatalf("unexpected error finishing upload: %v", err)
		}
	}

	if err = ms.Put(env.ctx, sm); err != nil {
		t.Fatalf("unexpected error putting manifest: %v", err)
	}

	exists, err = ms.ExistsByTag(env.ctx, env.tag)
	if err != nil {
		t.Fatalf("unexpected error checking manifest existence: %v", err)
	}

	if !exists {
		t.Fatalf("manifest should exist")
	}

	fetchedManifest, err := ms.GetByTag(env.ctx, env.tag)
	if err != nil {
		t.Fatalf("unexpected error fetching manifest: %v", err)
	}

	if !reflect.DeepEqual(fetchedManifest, sm) {
		t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedManifest, sm)
	}

	fetchedJWS, err := libtrust.ParsePrettySignature(fetchedManifest.Raw, "signatures")
	if err != nil {
		t.Fatalf("unexpected error parsing jws: %v", err)
	}

	payload, err := fetchedJWS.Payload()
	if err != nil {
		t.Fatalf("unexpected error extracting payload: %v", err)
	}

	// Now that we have a payload, take a moment to check that the manifest is
	// return by the payload digest.
	dgst, err := digest.FromBytes(payload)
	if err != nil {
		t.Fatalf("error getting manifest digest: %v", err)
	}

	exists, err = ms.Exists(env.ctx, dgst)
	if err != nil {
		t.Fatalf("error checking manifest existence by digest: %v", err)
	}

	if !exists {
		t.Fatalf("manifest %s should exist", dgst)
	}

	fetchedByDigest, err := ms.Get(env.ctx, dgst)
	if err != nil {
		t.Fatalf("unexpected error fetching manifest by digest: %v", err)
	}

	if !reflect.DeepEqual(fetchedByDigest, fetchedManifest) {
		t.Fatalf("fetched manifest not equal: %#v != %#v", fetchedByDigest, fetchedManifest)

func (s *Instance) GetProperJWS() (*libtrust.JSONSignature, error) {
	payloadJSON, _ := s.Payload.ToJSON()
	jws, err := libtrust.ParsePrettySignature(payloadJSON, "signatures")
	return jws, err
}

// loadManifest loads a manifest from a byte array and verifies its content.
// The signature must be verified or an error is returned. If the manifest
// contains no signatures by a trusted key for the name in the manifest, the
// image is not considered verified. The parsed manifest object and a boolean
// for whether the manifest is verified is returned.
func (s *TagStore) loadManifest(eng *engine.Engine, manifestBytes []byte, dgst, ref string) (*registry.ManifestData, bool, error) {
	sig, err := libtrust.ParsePrettySignature(manifestBytes, "signatures")
	if err != nil {
		return nil, false, fmt.Errorf("error parsing payload: %s", err)
	}

	keys, err := sig.Verify()
	if err != nil {
		return nil, false, fmt.Errorf("error verifying payload: %s", err)
	}

	payload, err := sig.Payload()
	if err != nil {
		return nil, false, fmt.Errorf("error retrieving payload: %s", err)
	}

	var manifestDigest digest.Digest

	if dgst != "" {
		manifestDigest, err = digest.ParseDigest(dgst)
		if err != nil {
			return nil, false, fmt.Errorf("invalid manifest digest from registry: %s", err)
		}

		dgstVerifier, err := digest.NewDigestVerifier(manifestDigest)
		if err != nil {
			return nil, false, fmt.Errorf("unable to verify manifest digest from registry: %s", err)
		}

		dgstVerifier.Write(payload)

		if !dgstVerifier.Verified() {
			computedDigest, _ := digest.FromBytes(payload)
			return nil, false, fmt.Errorf("unable to verify manifest digest: registry has %q, computed %q", manifestDigest, computedDigest)
		}
	}

	if utils.DigestReference(ref) && ref != manifestDigest.String() {
		return nil, false, fmt.Errorf("mismatching image manifest digest: got %q, expected %q", manifestDigest, ref)
	}

	var manifest registry.ManifestData
	if err := json.Unmarshal(payload, &manifest); err != nil {
		return nil, false, fmt.Errorf("error unmarshalling manifest: %s", err)
	}
	if manifest.SchemaVersion != 1 {
		return nil, false, fmt.Errorf("unsupported schema version: %d", manifest.SchemaVersion)
	}

	var verified bool
	for _, key := range keys {
		job := eng.Job("trust_key_check")
		b, err := key.MarshalJSON()
		if err != nil {
			return nil, false, fmt.Errorf("error marshalling public key: %s", err)
		}
		namespace := manifest.Name
		if namespace[0] != '/' {
			namespace = "/" + namespace
		}
		stdoutBuffer := bytes.NewBuffer(nil)

		job.Args = append(job.Args, namespace)
		job.Setenv("PublicKey", string(b))
		// Check key has read/write permission (0x03)
		job.SetenvInt("Permission", 0x03)
		job.Stdout.Add(stdoutBuffer)
		if err = job.Run(); err != nil {
			return nil, false, fmt.Errorf("error running key check: %s", err)
		}
		result := engine.Tail(stdoutBuffer, 1)
		logrus.Debugf("Key check result: %q", result)
		if result == "verified" {
			verified = true
		}
	}

	return &manifest, verified, nil
}

// loadManifest loads a manifest from a byte array and verifies its content.
// The signature must be verified or an error is returned. If the manifest
// contains no signatures by a trusted key for the name in the manifest, the
// image is not considered verified. The parsed manifest object and a boolean
// for whether the manifest is verified is returned.
func (s *TagStore) loadManifest(manifestBytes []byte, dgst, ref string) (*registry.ManifestData, bool, error) {
	sig, err := libtrust.ParsePrettySignature(manifestBytes, "signatures")
	if err != nil {
		return nil, false, fmt.Errorf("error parsing payload: %s", err)
	}

	keys, err := sig.Verify()
	if err != nil {
		return nil, false, fmt.Errorf("error verifying payload: %s", err)
	}

	payload, err := sig.Payload()
	if err != nil {
		return nil, false, fmt.Errorf("error retrieving payload: %s", err)
	}

	var manifestDigest digest.Digest

	if dgst != "" {
		manifestDigest, err = digest.ParseDigest(dgst)
		if err != nil {
			return nil, false, fmt.Errorf("invalid manifest digest from registry: %s", err)
		}

		dgstVerifier, err := digest.NewDigestVerifier(manifestDigest)
		if err != nil {
			return nil, false, fmt.Errorf("unable to verify manifest digest from registry: %s", err)
		}

		dgstVerifier.Write(payload)

		if !dgstVerifier.Verified() {
			computedDigest, _ := digest.FromBytes(payload)
			return nil, false, fmt.Errorf("unable to verify manifest digest: registry has %q, computed %q", manifestDigest, computedDigest)
		}
	}

	if utils.DigestReference(ref) && ref != manifestDigest.String() {
		return nil, false, fmt.Errorf("mismatching image manifest digest: got %q, expected %q", manifestDigest, ref)
	}

	var manifest registry.ManifestData
	if err := json.Unmarshal(payload, &manifest); err != nil {
		return nil, false, fmt.Errorf("error unmarshalling manifest: %s", err)
	}
	if manifest.SchemaVersion != 1 {
		return nil, false, fmt.Errorf("unsupported schema version: %d", manifest.SchemaVersion)
	}

	var verified bool
	for _, key := range keys {
		namespace := manifest.Name
		if namespace[0] != '/' {
			namespace = "/" + namespace
		}
		b, err := key.MarshalJSON()
		if err != nil {
			return nil, false, fmt.Errorf("error marshalling public key: %s", err)
		}
		// Check key has read/write permission (0x03)
		v, err := s.trustService.CheckKey(namespace, b, 0x03)
		if err != nil {
			vErr, ok := err.(trust.NotVerifiedError)
			if !ok {
				return nil, false, fmt.Errorf("error running key check: %s", err)
			}
			logrus.Debugf("Key check result: %v", vErr)
		}
		verified = v
		if verified {
			logrus.Debug("Key check result: verified")
		}
	}
	return &manifest, verified, nil
}