This adds code to generate a VSA

https://issues.redhat.com/browse/EC-189

internal/applicationsnapshot/attestation_test.go

@@ -22,6 +22,7 @@ import (
 	"testing"
 
 	"github.com/gkampitakis/go-snaps/snaps"
+	"github.com/in-toto/in-toto-golang/in_toto"
 	"github.com/stretchr/testify/assert"
 
 	app "github.com/enterprise-contract/ec-cli/application/v1alpha1"
@@ -143,6 +144,14 @@ func (a mockAttestation) Signatures() []signature.EntitySignature {
 	return nil
 }
 
+func (a mockAttestation) Digest() map[string]string {
+	return map[string]string{}
+}
+
+func (a mockAttestation) Subject() []in_toto.Subject {
+	return []in_toto.Subject{}
+}
+
 func att(data string) attestation.Attestation {
 	return &mockAttestation{
 		data: data,

internal/attestation/attestation.go

@@ -38,6 +38,8 @@ type Attestation interface {
 	PredicateType() string
 	Statement() []byte
 	Signatures() []signature.EntitySignature
+	Subject() []in_toto.Subject
+	Digest() map[string]string
 }
 
 // Extract the payload from a DSSE signature OCI layer
@@ -137,13 +139,20 @@ func ProvenanceFromSignature(sig oci.Signature) (Attestation, error) {
 		return nil, fmt.Errorf("cannot create signed entity: %w", err)
 	}
 
-	return provenance{statement: statement, data: embedded, signatures: signatures}, nil
+	digest, err := sig.Digest()
+	if err != nil {
+		return nil, err
+	}
+
+	return provenance{statement: statement, data: embedded, signatures: signatures, digest: map[string]string{digest.Algorithm: digest.String()}}, nil
 }
 
 type provenance struct {
 	statement  in_toto.Statement
 	data       []byte
 	signatures []signature.EntitySignature
+	uri        string
+	digest     map[string]string
 }
 
 func (p provenance) Type() string {
@@ -162,17 +171,27 @@ func (p provenance) Signatures() []signature.EntitySignature {
 	return p.signatures
 }
 
+func (p provenance) Digest() map[string]string {
+	return p.digest
+}
+
+func (p provenance) Subject() []in_toto.Subject {
+	return p.statement.Subject
+}
+
 // Todo: It seems odd that this does not contain the statement.
 // (See also the equivalent method in slsa_provenance_02.go)
 func (p provenance) MarshalJSON() ([]byte, error) {
 	val := struct {
 		Type          string                      `json:"type"`
 		PredicateType string                      `json:"predicateType"`
 		Signatures    []signature.EntitySignature `json:"signatures"`
+		Digest        map[string]string           `json:"digest"`
 	}{
 		Type:          p.Type(),
 		PredicateType: p.PredicateType(),
 		Signatures:    p.Signatures(),
+		Digest:        p.Digest(),
 	}
 
 	return json.Marshal(val)

internal/attestation/slsa_provenance_02.go

@@ -64,13 +64,19 @@ func SLSAProvenanceFromSignature(sig oci.Signature) (Attestation, error) {
 		return nil, fmt.Errorf("cannot create signed entity: %w", err)
 	}
 
-	return slsaProvenance{statement: statement, data: embedded, signatures: signatures}, nil
+	digest, err := sig.Digest()
+	if err != nil {
+		return nil, err
+	}
+
+	return slsaProvenance{statement: statement, data: embedded, signatures: signatures, digest: map[string]string{digest.Algorithm: digest.String()}}, nil
 }
 
 type slsaProvenance struct {
 	statement  in_toto.ProvenanceStatementSLSA02
 	data       []byte
 	signatures []signature.EntitySignature
+	digest     map[string]string
 }
 
 func (a slsaProvenance) Type() string {
@@ -90,6 +96,14 @@ func (a slsaProvenance) Signatures() []signature.EntitySignature {
 	return a.signatures
 }
 
+func (a slsaProvenance) Digest() map[string]string {
+	return a.digest
+}
+
+func (a slsaProvenance) Subject() []in_toto.Subject {
+	return a.statement.Subject
+}
+
 // Todo: It seems odd that this does not contain the statement.
 // (See also the equivalent method in attestation.go)
 func (a slsaProvenance) MarshalJSON() ([]byte, error) {
@@ -98,11 +112,13 @@ func (a slsaProvenance) MarshalJSON() ([]byte, error) {
 		PredicateType      string                      `json:"predicateType"`
 		PredicateBuildType string                      `json:"predicateBuildType"`
 		Signatures         []signature.EntitySignature `json:"signatures"`
+		Digest             map[string]string           `json:"digest"`
 	}{
 		Type:               a.statement.Type,
 		PredicateType:      a.statement.PredicateType,
 		PredicateBuildType: a.statement.Predicate.BuildType,
 		Signatures:         a.signatures,
+		Digest:             a.digest,
 	}
 
 	return json.Marshal(val)

internal/attestation/vsa.go

@@ -0,0 +1,125 @@
+// Copyright The Enterprise Contract Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package attestation
+
+import (
+	"strings"
+	"time"
+
+	"github.com/enterprise-contract/ec-cli/internal/evaluator"
+	"github.com/enterprise-contract/ec-cli/internal/policy"
+	"github.com/enterprise-contract/ec-cli/internal/policy/source"
+	"github.com/in-toto/in-toto-golang/in_toto"
+)
+
+const (
+	// Make it visible elsewhere
+	PredicateVSAProvenance = "https://slsa.dev/verification_summary/v1"
+	StatmentVSA            = "https://in-toto.io/Statement/v1"
+)
+
+type ProvenanceStatementVSA struct {
+	in_toto.StatementHeader
+	Predicate predicate `json:"predicate"`
+}
+
+type policySource struct {
+	uri    string
+	digest map[string]string
+}
+
+type attestationSource struct {
+	uri    string
+	digest map[string]string
+}
+
+type predicate struct {
+	Verifier            map[string]string   `json:"verifier"`
+	TimeVerified        string              `json:"timeVerified"`
+	ResourceUri         string              `json:"resourceUri"`
+	Policies            []policySource      `json:"policies"`
+	InputAttestations   []attestationSource `json:"intputAttestations"`
+	VerificationResult  string              `json:"verificationResult"`
+	VerifiedRules       []string            `json:"verifiedRules"`
+	VerifiedCollections []string            `json:"verfiedCollection"`
+	SlsaVersion         string              `json:"slsaVersion"`
+}
+
+func VsaFromImageValidation(results []evaluator.Outcome, policies []source.PolicySource, policy policy.Policy, attestations []Attestation) (ProvenanceStatementVSA, error) {
+	var verifiedPolicies []policySource
+	for _, p := range policies {
+		verifiedPolicies = append(verifiedPolicies, policySource{uri: p.PolicyUrl()})
+	}
+
+	var verfiedResults int
+	var verifiedLevels []string
+	for _, res := range results {
+		for _, success := range res.Successes {
+			verifiedLevels = append(verifiedLevels, success.Metadata["code"].(string))
+		}
+		verfiedResults = verfiedResults + len(res.Failures)
+	}
+	verificationResult := "Success"
+	if verfiedResults > 0 {
+		verificationResult = "Failure"
+	}
+
+	var verifiedCollections []string
+	for _, source := range policy.Spec().Sources {
+		for _, include := range source.Config.Include {
+			splitInclude := strings.Split(include, "@")
+			if len(splitInclude) > 1 {
+				verifiedCollections = append(verifiedCollections, splitInclude[1])
+			}
+		}
+	}
+
+	var slsaVersion string
+	var digest map[string]string
+	var subject []in_toto.Subject
+	for _, sp := range attestations {
+		slsaVersion = sp.PredicateType()
+		digest = sp.Digest()
+		subject = sp.Subject()
+	}
+
+	return ProvenanceStatementVSA{
+		StatementHeader: in_toto.StatementHeader{
+			Type:          StatmentVSA,
+			PredicateType: PredicateVSAProvenance,
+			Subject:       subject,
+		},
+		Predicate: predicate{
+			Verifier: map[string]string{
+				"id": "ec",
+			},
+			TimeVerified: time.Now().String(),
+			// need to check on this. Sounds like it should be the same as the subject, but not compatible types
+			ResourceUri: subject[0].Name,
+			Policies:    verifiedPolicies,
+			InputAttestations: []attestationSource{
+				{
+					digest: digest,
+				},
+			},
+			VerificationResult:  verificationResult,
+			VerifiedRules:       verifiedLevels,
+			VerifiedCollections: verifiedCollections,
+			SlsaVersion:         slsaVersion,
+		},
+	}, nil
+}

internal/definition/validate_test.go

@@ -49,6 +49,10 @@ func (e mockEvaluator) CapabilitiesPath() string {
 	return ""
 }
 
+func (e mockEvaluator) GetPolicySources() []source.PolicySource {
+	return []source.PolicySource{}
+}
+
 func (b badMockEvaluator) Evaluate(ctx context.Context, inputs []string) ([]evaluator.Outcome, evaluator.Data, error) {
 	return nil, nil, errors.New("Evaluator error")
 }
@@ -60,6 +64,10 @@ func (e badMockEvaluator) CapabilitiesPath() string {
 	return ""
 }
 
+func (e badMockEvaluator) GetPolicySources() []source.PolicySource {
+	return []source.PolicySource{}
+}
+
 func mockNewPipelineDefinitionFile(ctx context.Context, fpath []string, sources []source.PolicySource, namespace []string) (*definition.Definition, error) {
 	return &definition.Definition{
 		Evaluator: mockEvaluator{},

internal/evaluation_target/application_snapshot_image/application_snapshot_image.go

@@ -71,6 +71,10 @@ type ApplicationSnapshotImage struct {
 	component        app.SnapshotComponent
 }
 
+func (a ApplicationSnapshotImage) GetReference() name.Reference {
+	return a.reference
+}
+
 // NewApplicationSnapshotImage returns an ApplicationSnapshotImage struct with reference, checkOpts, and evaluator ready to use.
 func NewApplicationSnapshotImage(ctx context.Context, component app.SnapshotComponent, p policy.Policy) (*ApplicationSnapshotImage, error) {
 	opts, err := p.CheckOpts()
@@ -233,6 +237,7 @@ func (a *ApplicationSnapshotImage) ValidateAttestationSignature(ctx context.Cont
 	// Set the ClaimVerifier on a shallow *copy* of CheckOpts to avoid unexpected side-effects
 	opts := a.checkOpts
 	opts.ClaimVerifier = cosign.IntotoSubjectClaimVerifier
+
 	layers, _, err := NewClient(ctx).VerifyImageAttestations(ctx, a.reference, &opts)
 	if err != nil {
 		return err
@@ -333,6 +338,14 @@ func (a *ApplicationSnapshotImage) Signatures() []signature.EntitySignature {
 	return a.signatures
 }
 
+func (a *ApplicationSnapshotImage) ResolveDigest(ctx context.Context) (string, error) {
+	digest, err := NewClient(ctx).ResolveDigest(a.reference, &a.checkOpts)
+	if err != nil {
+		return "", err
+	}
+	return digest, nil
+}
+
 type attestationData struct {
 	json.RawMessage                             // Deprecated
 	Extra           attestationExtraData        `json:"extra"` // Deprecated

internal/evaluation_target/application_snapshot_image/application_snapshot_image_test.go

@@ -147,6 +147,14 @@ func (f fakeAtt) Signatures() []signature.EntitySignature {
 	return f.signatures
 }
 
+func (f fakeAtt) Digest() map[string]string {
+	return map[string]string{}
+}
+
+func (f fakeAtt) Subject() []in_toto.Subject {
+	return []in_toto.Subject{}
+}
+
 type opts func(*fakeAtt)
 
 func createSimpleAttestation(statement *in_toto.ProvenanceStatementSLSA02, o ...opts) attestation.Attestation {
@@ -443,6 +451,10 @@ func (c *MockClient) Head(name name.Reference, options ...remote.Option) (*v1.De
 	return args.Get(0).(*v1.Descriptor), args.Error(1)
 }
 
+func (c *MockClient) ResolveDigest(ref name.Reference, opts *cosign.CheckOpts) (string, error) {
+	return "", nil
+}
+
 func TestValidateImageSignatureClaims(t *testing.T) {
 	ref := name.MustParseReference("registry.io/repository/image:tag")
 	a := ApplicationSnapshotImage{

internal/evaluation_target/application_snapshot_image/client.go

@@ -21,9 +21,11 @@ import (
 
 	"github.com/google/go-containerregistry/pkg/name"
 	gcr "github.com/google/go-containerregistry/pkg/v1"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/remote"
 	"github.com/sigstore/cosign/v2/pkg/cosign"
 	"github.com/sigstore/cosign/v2/pkg/oci"
+	ociremote "github.com/sigstore/cosign/v2/pkg/oci/remote"
 )
 
 type contextKey string
@@ -36,6 +38,7 @@ type Client interface {
 	VerifyImageSignatures(context.Context, name.Reference, *cosign.CheckOpts) ([]oci.Signature, bool, error)
 	VerifyImageAttestations(context.Context, name.Reference, *cosign.CheckOpts) ([]oci.Signature, bool, error)
 	Head(name.Reference, ...remote.Option) (*gcr.Descriptor, error)
+	ResolveDigest(name.Reference, *cosign.CheckOpts) (string, error)
 }
 
 func WithClient(ctx context.Context, client Client) context.Context {
@@ -66,3 +69,15 @@ func (c *defaultClient) VerifyImageAttestations(ctx context.Context, ref name.Re
 func (c *defaultClient) Head(ref name.Reference, opts ...remote.Option) (*gcr.Descriptor, error) {
 	return remote.Head(ref, opts...)
 }
+
+func (c *defaultClient) ResolveDigest(ref name.Reference, opts *cosign.CheckOpts) (string, error) {
+	digest, err := ociremote.ResolveDigest(ref, opts.RegistryClientOpts...)
+	if err != nil {
+		return "", err
+	}
+	h, err := v1.NewHash(digest.Identifier())
+	if err != nil {
+		return "", err
+	}
+	return h.String(), nil
+}

internal/evaluator/conftest_evaluator.go

@@ -260,6 +260,10 @@ func NewConftestEvaluatorWithNamespace(ctx context.Context, policySources []sour
 	return c, nil
 }
 
+func (c conftestEvaluator) GetPolicySources() []source.PolicySource {
+	return c.policySources
+}
+
 // Destroy removes the working directory
 func (c conftestEvaluator) Destroy() {
 	if os.Getenv("EC_DEBUG") == "" {