errors: add error for wild card scope validation (#340)

Signed-off-by: Sajay Antony <sajaya@microsoft.com>

verifier/trustpolicy/trustpolicy.go

@@ -550,7 +550,15 @@ func validateRegistryScopeFormat(scope string) error {
 	// https://github.com/distribution/distribution/blob/main/reference/regexp.go#L31
 	domainRegexp := regexp.MustCompile(`^(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])(?:(?:\.(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9]))+)?(?::[0-9]+)?$`)
 	repositoryRegexp := regexp.MustCompile(`^[a-z0-9]+(?:(?:(?:[._]|__|[-]*)[a-z0-9]+)+)?(?:(?:/[a-z0-9]+(?:(?:(?:[._]|__|[-]*)[a-z0-9]+)+)?)+)?$`)
-	errorMessage := "registry scope %q is not valid, make sure it is a fully qualified registry URL without the scheme/protocol, e.g domain.com/my/repository OR a local trust policy scope, e.g local/myOCILayout"
+	ensureMessage := "make sure it is a fully qualified repository without the scheme, protocol or tag. For example domain.com/my/repository or a local scope like local/myOCILayout"
+	errorMessage := "registry scope %q is not valid, " + ensureMessage
+	errorWildCardMessage := "registry scope %q with wild card(s) is not valid, " + ensureMessage
+
+	// Check for presence of * in scope
+	if len(scope) > 1 && strings.Contains(scope, "*") {
+		return fmt.Errorf(errorWildCardMessage, scope)
+	}
+
 	domain, repository, found := strings.Cut(scope, "/")
 	if !found {
 		return fmt.Errorf(errorMessage, scope)

verifier/trustpolicy/trustpolicy_test.go

@@ -206,7 +206,21 @@ func TestInvalidRegistryScopes(t *testing.T) {
 		policyStatement.RegistryScopes = []string{scope}
 		policyDoc.TrustPolicies = []TrustPolicy{policyStatement}
 		err := policyDoc.Validate()
-		if err == nil || err.Error() != "registry scope \""+scope+"\" is not valid, make sure it is a fully qualified registry URL without the scheme/protocol, e.g domain.com/my/repository OR a local trust policy scope, e.g local/myOCILayout" {
+		if err == nil || err.Error() != "registry scope \""+scope+"\" is not valid, make sure it is a fully qualified repository without the scheme, protocol or tag. For example domain.com/my/repository or a local scope like local/myOCILayout" {
+			t.Fatalf("invalid registry scope should return error. Error : %q", err)
+		}
+	}
+
+	// Test invalid scope with wild card suffix
+
+	invalidWildCardScopes := []string{"example.com/*", "*/", "example*/", "ex*test"}
+	for _, scope := range invalidWildCardScopes {
+		policyDoc := dummyPolicyDocument()
+		policyStatement := dummyPolicyStatement()
+		policyStatement.RegistryScopes = []string{scope}
+		policyDoc.TrustPolicies = []TrustPolicy{policyStatement}
+		err := policyDoc.Validate()
+		if err == nil || err.Error() != "registry scope \""+scope+"\" with wild card(s) is not valid, make sure it is a fully qualified repository without the scheme, protocol or tag. For example domain.com/my/repository or a local scope like local/myOCILayout" {
 			t.Fatalf("invalid registry scope should return error. Error : %q", err)
 		}
 	}
@@ -215,7 +229,7 @@ func TestInvalidRegistryScopes(t *testing.T) {
 // TestValidRegistryScopes tests valid scopes are accepted
 func TestValidRegistryScopes(t *testing.T) {
 	validScopes := []string{
-		"example.com/rep", "example.com:8080/rep/rep2", "example.com/rep/subrep/subsub",
+		"*", "example.com/rep", "example.com:8080/rep/rep2", "example.com/rep/subrep/subsub",
 		"10.10.10.10:8080/rep/rep2", "domain/rep", "domain:1234/rep",
 	}