Merge pull request #227 from mtrmac/canonicalize-VerifyDockerManifestSignature

Canonicalize docker references in signature.VerifyDockerManifestSignature

Author: mtrmac

signature/docker.go

@@ -5,6 +5,7 @@ package signature
 import (
 	"fmt"
 
+	"github.com/containers/image/docker/reference"
 	"github.com/containers/image/manifest"
 	"github.com/opencontainers/go-digest"
 )
@@ -24,6 +25,10 @@ func SignDockerManifest(m []byte, dockerReference string, mech SigningMechanism,
 // using mech.
 func VerifyDockerManifestSignature(unverifiedSignature, unverifiedManifest []byte,
 	expectedDockerReference string, mech SigningMechanism, expectedKeyIdentity string) (*Signature, error) {
+	expectedRef, err := reference.ParseNamed(expectedDockerReference)
+	if err != nil {
+		return nil, err
+	}
 	sig, err := verifyAndExtractSignature(mech, unverifiedSignature, signatureAcceptanceRules{
 		validateKeyIdentity: func(keyIdentity string) error {
 			if keyIdentity != expectedKeyIdentity {
@@ -32,7 +37,11 @@ func VerifyDockerManifestSignature(unverifiedSignature, unverifiedManifest []byt
 			return nil
 		},
 		validateSignedDockerReference: func(signedDockerReference string) error {
-			if signedDockerReference != expectedDockerReference {
+			signedRef, err := reference.ParseNamed(signedDockerReference)
+			if err != nil {
+				return InvalidSignatureError{msg: fmt.Sprintf("Invalid docker reference %s in signature", signedDockerReference)}
+			}
+			if signedRef.String() != expectedRef.String() {
 				return InvalidSignatureError{msg: fmt.Sprintf("Docker reference %s does not match %s",
 					signedDockerReference, expectedDockerReference)}
 			}

signature/docker_test.go

@@ -52,8 +52,19 @@ func TestVerifyDockerManifestSignature(t *testing.T) {
 	assert.Equal(t, TestImageSignatureReference, sig.DockerReference)
 	assert.Equal(t, TestImageManifestDigest, sig.DockerManifestDigest)
 
+	// Verification using a different canonicalization of TestImageSignatureReference
+	sig, err = VerifyDockerManifestSignature(signature, manifest, "docker.io/"+TestImageSignatureReference, mech, TestKeyFingerprint)
+	require.NoError(t, err)
+	assert.Equal(t, TestImageSignatureReference, sig.DockerReference)
+	assert.Equal(t, TestImageManifestDigest, sig.DockerManifestDigest)
+
 	// For extra paranoia, test that we return nil data on error.
 
+	// Invalid docker reference on input
+	sig, err = VerifyDockerManifestSignature(signature, manifest, "UPPERCASEISINVALID", mech, TestKeyFingerprint)
+	assert.Error(t, err)
+	assert.Nil(t, sig)
+
 	// Error computing Docker manifest
 	invalidManifest, err := ioutil.ReadFile("fixtures/v2s1-invalid-signatures.manifest.json")
 	require.NoError(t, err)
@@ -72,6 +83,12 @@ func TestVerifyDockerManifestSignature(t *testing.T) {
 	assert.Error(t, err)
 	assert.Nil(t, sig)
 
+	// Invalid reference in the signature
+	invalidReferenceSignature, err := ioutil.ReadFile("fixtures/invalid-reference.signature")
+	sig, err = VerifyDockerManifestSignature(invalidReferenceSignature, manifest, TestImageSignatureReference, mech, TestKeyFingerprint)
+	assert.Error(t, err)
+	assert.Nil(t, sig)
+
 	// Docker reference mismatch
 	sig, err = VerifyDockerManifestSignature(signature, manifest, "example.com/doesnt/match", mech, TestKeyFingerprint)
 	assert.Error(t, err)