add --certificate-bundle flag to 'cosign verify'

Related to issue sigstore#3462.  Current commit adds the flag
to verify the CLI options.  The new flag doesn't have
any effect yet (will add in follow-up PRs).

Signed-off-by: Dmitry S <dsavints@gmail.com>

cmd/cosign/cli/options/certificate.go

@@ -33,6 +33,7 @@ type CertVerifyOptions struct {
 	CertGithubWorkflowName       string
 	CertGithubWorkflowRepository string
 	CertGithubWorkflowRef        string
+	CertBundle                   string
 	CertChain                    string
 	SCT                          string
 	IgnoreSCT                    bool
@@ -75,12 +76,18 @@ func (o *CertVerifyOptions) AddFlags(cmd *cobra.Command) {
 	cmd.Flags().StringVar(&o.CertGithubWorkflowRef, "certificate-github-workflow-ref", "",
 		"contains the ref claim from the GitHub OIDC Identity token that contains the git ref that the workflow run was based upon.")
 	// -- Cert extensions end --
+	cmd.Flags().StringVar(&o.CertBundle, "certificate-bundle", "",
+		"path to a bundle file of CA certificates in PEM format which will be needed "+
+			"when building the certificate chains for the signing certificate. Conflicts with --certificate-chain.")
+	_ = cmd.Flags().SetAnnotation("certificate-bundle", cobra.BashCompFilenameExt, []string{"cert"})
+
 	cmd.Flags().StringVar(&o.CertChain, "certificate-chain", "",
 		"path to a list of CA certificates in PEM format which will be needed "+
 			"when building the certificate chain for the signing certificate. "+
 			"Must start with the parent intermediate CA certificate of the "+
-			"signing certificate and end with the root certificate")
+			"signing certificate and end with the root certificate. Conflicts with --certificate-bundle.")
 	_ = cmd.Flags().SetAnnotation("certificate-chain", cobra.BashCompFilenameExt, []string{"cert"})
+	cmd.MarkFlagsMutuallyExclusive("certificate-bundle", "certificate-chain")
 
 	cmd.Flags().StringVar(&o.SCT, "sct", "",
 		"path to a detached Signed Certificate Timestamp, formatted as a RFC6962 AddChainResponse struct. "+

cmd/cosign/cli/verify.go

@@ -115,6 +115,7 @@ against the transparency log.`,
 				CertGithubWorkflowName:       o.CertVerify.CertGithubWorkflowName,
 				CertGithubWorkflowRepository: o.CertVerify.CertGithubWorkflowRepository,
 				CertGithubWorkflowRef:        o.CertVerify.CertGithubWorkflowRef,
+				CertBundle:                   o.CertVerify.CertBundle,
 				CertChain:                    o.CertVerify.CertChain,
 				IgnoreSCT:                    o.CertVerify.IgnoreSCT,
 				SCTRef:                       o.CertVerify.SCT,

cmd/cosign/cli/verify/verify.go

@@ -60,6 +60,7 @@ type VerifyCommand struct {
 	CertGithubWorkflowName       string
 	CertGithubWorkflowRepository string
 	CertGithubWorkflowRef        string
+	CertBundle                   string
 	CertChain                    string
 	CertOidcProvider             string
 	IgnoreSCT                    bool