incorporate code reviews

Signed-off-by: Reinhard Tartler <siretart@gmail.com>

signature/fulcio_cert.go

@@ -1,3 +1,6 @@
+//go:build !containers_image_fulcio_stub
+// +build !containers_image_fulcio_stub
+
 package signature
 
 import (

signature/fulcio_cert_stub.go

@@ -0,0 +1,28 @@
+//go:build containers_image_fulcio_stub
+// +build containers_image_fulcio_stub
+
+package signature
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/x509"
+	"errors"
+)
+
+type fulcioTrustRoot struct {
+	caCertificates *x509.CertPool
+	oidcIssuer     string
+	subjectEmail   string
+}
+
+func (f *fulcioTrustRoot) validate() error {
+	return errors.New("fulcio disabled at compile-time")
+}
+
+func verifyRekorFulcio(rekorPublicKey *ecdsa.PublicKey, fulcioTrustRoot *fulcioTrustRoot, untrustedRekorSET []byte,
+	untrustedCertificateBytes []byte, untrustedIntermediateChainBytes []byte, untrustedBase64Signature string,
+	untrustedPayloadBytes []byte) (crypto.PublicKey, error) {
+	return nil, errors.New("fulcio diabled at compile-time")
+
+}

signature/fulcio_cert_test.go

@@ -1,3 +1,6 @@
+//go:build !containers_image_fulcio_stub
+// +build !containers_image_fulcio_stub
+
 package signature
 
 import (

signature/internal/rekor_set.go

@@ -1,3 +1,6 @@
+//go:build !containers_image_rekor_stub
+// +build !containers_image_rekor_stub
+
 package internal
 
 import (

signature/internal/rekor_set_stub.go

@@ -0,0 +1,15 @@
+//go:build containers_image_rekor_stub
+// +build containers_image_rekor_stub
+
+package internal
+
+import (
+	"crypto/ecdsa"
+	"time"
+)
+
+// VerifyRekorSET verifies that unverifiedRekorSET is correctly signed by publicKey and matches the rest of the data.
+// Returns bundle upload time on success.
+func VerifyRekorSET(publicKey *ecdsa.PublicKey, unverifiedRekorSET []byte, unverifiedKeyOrCertBytes []byte, unverifiedBase64Signature string, unverifiedPayloadBytes []byte) (time.Time, error) {
+	return time.Time{}, NewInvalidSignatureError("rekor disabled at compile-time")
+}

signature/internal/rekor_set_test.go

@@ -1,3 +1,6 @@
+//go:build !containers_image_rekor_stub
+// +build !containers_image_rekor_stub
+
 package internal
 
 import (

signature/policy_eval_sigstore_test.go

@@ -1,3 +1,6 @@
+//go:build !containers_image_fulcio_stub
+// +build !containers_image_fulcio_stub
+
 // Policy evaluation for prCosignSigned.
 
 package signature

signature/sigstore/fulcio/no_fulcio.go → signature/sigstore/fulcio/fulcio_stub.go

@@ -13,7 +13,7 @@ import (
 
 func WithFulcioAndPreexistingOIDCIDToken(fulcioURL *url.URL, oidcIDToken string) internal.Option {
 	return func(s *internal.SigstoreSigner) error {
-		return fmt.Errorf("Fulcio disabled at compile time")
+		return fmt.Errorf("fulcio disabled at compile time")
 	}
 }
 
@@ -24,7 +24,7 @@ func WithFulcioAndPreexistingOIDCIDToken(fulcioURL *url.URL, oidcIDToken string)
 func WithFulcioAndDeviceAuthorizationGrantOIDC(fulcioURL *url.URL, oidcIssuerURL *url.URL, oidcClientID, oidcClientSecret string,
 	interactiveOutput io.Writer) internal.Option {
 	return func(s *internal.SigstoreSigner) error {
-		return fmt.Errorf("Fulcio disabled at compile time")
+		return fmt.Errorf("fulcio disabled at compile time")
 	}
 }
 
@@ -40,6 +40,6 @@ func WithFulcioAndDeviceAuthorizationGrantOIDC(fulcioURL *url.URL, oidcIssuerURL
 func WithFulcioAndInteractiveOIDC(fulcioURL *url.URL, oidcIssuerURL *url.URL, oidcClientID, oidcClientSecret string,
 	interactiveInput io.Reader, interactiveOutput io.Writer) internal.Option {
 	return func(s *internal.SigstoreSigner) error {
-		return fmt.Errorf("Fulcio disabled at compile time")
+		return fmt.Errorf("fulcio disabled at compile time")
 	}
 }

signature/sigstore/rekor/no_rekor.go → signature/sigstore/rekor/rekor_stub.go

@@ -12,6 +12,6 @@ import (
 
 func WithRekor(rekorURL *url.URL) signerInternal.Option {
 	return func(s *signerInternal.SigstoreSigner) error {
-		return fmt.Errorf("Rekor disabled at build time")
+		return fmt.Errorf("rekor disabled at build time")
 	}
 }