From d64905256a3e4bdae006728ff3e85ccd67f08afa Mon Sep 17 00:00:00 2001
From: Cedric Staub <css@css.bio>
Date: Fri, 24 Jun 2016 22:37:27 -0700
Subject: [PATCH] Improve formatting, show if self-signed

---
 display.go |  3 ++-
 verify.go  | 11 ++++++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/display.go b/display.go
index b55845e..8472bd9 100644
--- a/display.go
+++ b/display.go
@@ -35,7 +35,7 @@ import (
 var layout = `Serial: {{.SerialNumber}}
 Not Before: {{.NotBefore | certStart}}
 Not After : {{.NotAfter | certEnd}}
-Signature : {{.SignatureAlgorithm | algorithm}}
+Signature : {{.SignatureAlgorithm | algorithm}} {{if . | isSelfSigned}}(self-signed){{end}}
 Subject Info: {{if .Subject.CommonName}}
 	CommonName: {{.Subject.CommonName}}{{end}} {{if .Subject.Organization}}
 	Organization: {{.Subject.Organization}} {{end}} {{if .Subject.OrganizationalUnit}}
@@ -80,6 +80,7 @@ func displayCert(cert certWithAlias) {
 		"keyUsage":     keyUsage,
 		"extKeyUsage":  extKeyUsage,
 		"certWarnings": certWarnings,
+		"isSelfSigned": isSelfSigned,
 	}
 	t := template.New("Cert template").Funcs(funcMap)
 	t, _ = t.Parse(layout)
diff --git a/verify.go b/verify.go
index a9af5f5..54bbab4 100644
--- a/verify.go
+++ b/verify.go
@@ -69,6 +69,11 @@ func verifyChain(certs []*x509.Certificate, dnsName, caPath string) {
 			} else {
 				name = fmt.Sprintf("Serial #%s", cert.SerialNumber.String())
 			}
+
+			if isSelfSigned(cert) {
+				name += green.SprintfFunc()(" [self-signed]")
+			}
+
 			for _, alg := range badSignatureAlgorithms {
 				if cert.SignatureAlgorithm == alg {
 					name += red.SprintfFunc()(" [%s]", alg.String())
@@ -77,6 +82,10 @@ func verifyChain(certs []*x509.Certificate, dnsName, caPath string) {
 			}
 			names = append(names, name)
 		}
-		fmt.Printf("\t[%d] %s\n", i, strings.Join(names, "\n\t\t=> "))
+		fmt.Printf("[%d] %s\n", i, strings.Join(names, "\n\t=> "))
 	}
 }
+
+func isSelfSigned(cert *x509.Certificate) bool {
+	return cert.CheckSignatureFrom(cert) == nil
+}