initial working version with extensions

README.md

@@ -23,6 +23,7 @@ certinfo [flags] [<file>|<host:port> ...]
 | -chains       | whether to print verified chains as well (only applicable for host)                               |
 | -clipboard    | read input from clipboard (only if the clipboard is supported)                                    |
 | -expiry       | print expiry of certificates                                                                      |
+| -extensions   | whether to print extensions
 | -insecure     | whether a client verifies the server's certificate chain and host name (only applicable for host) |
 | -issuer-like  | print certificates with subject field containing supplied string                                  |
 | -no-duplicate | do not print duplicate certificates                                                               |

flag.go

@@ -19,6 +19,7 @@ type Flags struct {
 	IssuerLike  string
 	Insecure    bool
 	Chains      bool
+	Extensions  bool
 	Pem         bool
 	PemOnly     bool
 	Version     bool
@@ -46,6 +47,8 @@ func ParseFlags() (Flags, error) {
 		"whether a client verifies the server's certificate chain and host name (only applicable for host)")
 	flagSet.BoolVar(&flags.Chains, "chains", getBoolEnv("CERTINFO_CHAINS", false),
 		"whether to print verified chains as well (only applicable for host)")
+	flagSet.BoolVar(&flags.Extensions, "extensions", getBoolEnv("CERTINFO_EXTENSIONS", false),
+		"whether to print extensions")
 	flagSet.BoolVar(&flags.Pem, "pem", getBoolEnv("CERTINFO_PEM", false),
 		"whether to print pem as well")
 	flagSet.BoolVar(&flags.PemOnly, "pem-only", getBoolEnv("CERTINFO_PEM_ONLY", false),

main.go

@@ -48,7 +48,7 @@ func main() {
 		PrintPemOnly(certificatesFiles, flags.Chains)
 		return
 	}
-	PrintCertificatesLocations(certificatesFiles, flags.Chains, flags.Pem)
+	PrintCertificatesLocations(certificatesFiles, flags.Chains, flags.Pem, flags.Extensions)
 }
 
 func LoadCertificatesLocations(flags Flags) cert.CertificateLocations {