cert

package module
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 Go to latest Published: Apr 22, 2023 License: MIT Imports: 13 Imported by: 13

README

cert

build

Get server's certificate information.

Installation

For Mac it provide Homebrew integration. Please install like following.

$ brew tap genkiroid/homebrew-cert
$ brew install cert

For other platforms, Precompiled binaries for released versions are available in the releases page.

Or go install.

$ go install github.com/genkiroid/cert/cmd/cert@latest

Usage

Give domain names as arguments.

$ cert github.com google.co.jp
DomainName: github.com
IP:         192.30.255.113
Port:       443
Issuer:     DigiCert SHA2 Extended Validation Server CA
NotBefore:  2016-03-10 09:00:00 +0900 JST
NotAfter:   2018-05-17 21:00:00 +0900 JST
CommonName: github.com
SANs:       [github.com www.github.com]
Error:

DomainName: google.co.jp
IP:         216.58.196.227
Port:       443
Issuer:     Google Internet Authority G3
NotBefore:  2017-10-17 19:59:51 +0900 JST
NotAfter:   2018-01-09 19:00:00 +0900 JST
CommonName: *.google.co.jp
SANs:       [*.google.co.jp google.co.jp]
Error:

You can specify port number. So you can get server certificate information of not only web server but also mail server and others.

$ cert github.com google.co.jp:443 imap.gmail.com:993
DomainName: github.com
IP:         192.30.255.113
Port:       443
Issuer:     DigiCert SHA2 Extended Validation Server CA
NotBefore:  2016-03-10 09:00:00 +0900 JST
NotAfter:   2018-05-17 21:00:00 +0900 JST
CommonName: github.com
SANs:       [github.com www.github.com]
Error:

DomainName: google.co.jp
IP:         172.217.27.163
Port:       443
Issuer:     Google Internet Authority G3
NotBefore:  2017-10-17 19:59:51 +0900 JST
NotAfter:   2018-01-09 19:00:00 +0900 JST
CommonName: *.google.co.jp
SANs:       [*.google.co.jp google.co.jp]
Error:

DomainName: imap.gmail.com
IP:         64.233.188.108
Port:       993
Issuer:     Google Internet Authority G2
NotBefore:  2017-10-17 19:10:29 +0900 JST
NotAfter:   2017-12-29 09:00:00 +0900 JST
CommonName: imap.gmail.com
SANs:       [imap.gmail.com]
Error:

Options

$ cert --help
Usage of cert:
  -c string
        Specify cipher suite. Refer to https://golang.org/pkg/crypto/tls/#pkg-constants for supported cipher suites.
  -cipher string
        Specify cipher suite. Refer to https://golang.org/pkg/crypto/tls/#pkg-constants for supported cipher suites.
  -f string
        Output format. md: as markdown, json: as JSON.  (default "simple table")
  -format string
        Output format. md: as markdown, json: as JSON.  (default "simple table")
  -k    Skip verification of server's certificate chain and host name.
  -s int
        Timeout seconds. (default 3)
  -skip-verify
        Skip verification of server's certificate chain and host name.
  -t string
        Output format as Go template string or Go template file path.
  -template string
        Output format as Go template string or Go template file path.
  -timeout int
        Timeout seconds. (default 3)
  -u    Use UTC to represent NotBefore and NotAfter.
  -utc
        Use UTC to represent NotBefore and NotAfter.
  -v    Show version.
  -version
        Show version.
Output as JSON

Use cert -f json.

$ cert -f json github.com | jq .
[
  {
    "DomainName": "github.com",
    "IP": "192.30.255.112",
    "Port": "443",
    "Issuer": "DigiCert SHA2 Extended Validation Server CA",
    "CommonName": "github.com",
    "SANs": [
      "github.com",
      "www.github.com"
    ],
    "NotBefore": "2016-03-10 09:00:00 +0900 JST",
    "NotAfter": "2018-05-17 21:00:00 +0900 JST",
    "Error": ""
  }
]
Output as Markdown

Use cert -f md.

$ cert -f md github.com
DomainName | IP | Port | Issuer | NotBefore | NotAfter | CN | SANs | Error
--- | --- | --- | --- | --- | --- | --- | --- | ---
github.com | 192.30.255.113 | 443 | DigiCert SHA2 Extended Validation Server CA | 2016-03-10 09:00:00 +0900 JST | 2018-05-17 21:00:00 +0900 JST | github.com | github.com<br/>www.github.com<br/> |
DomainName IP Port Issuer NotBefore NotAfter CN SANs Error
github.com 192.30.255.113 443 DigiCert SHA2 Extended Validation Server CA 2016-03-10 09:00:00 +0900 JST 2018-05-17 21:00:00 +0900 JST github.com github.com
www.github.com
Specify output format by Go template

Use cert -t.

By direct string.

$ cert -t "{{range .}}{{.Issuer}}{{end}}" github.com
DigiCert SHA2 Extended Validation Server CA

By template file.

$ cat /tmp/cert_templ
{{range .}}{{range .CertChain}}Issuer: {{.Issuer.CommonName}}
{{end}}{{end}}
$
$ cert -t /tmp/cert_templ github.com
Issuer: DigiCert SHA2 Extended Validation Server CA
Issuer: DigiCert High Assurance EV Root CA
Specify cipher suite

see https://github.com/genkiroid/cert/issues/13

You can specify cipher suite. As a result, you can get the information of each certificate.

Note that the issuers are different in the following example.

# Get information of the certificate using RSA signature/public key algorithm.
$ cert -cipher TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305 cloudflaressl.com
DomainName: cloudflaressl.com
IP:         104.20.47.142
Port:       443
Issuer:     COMODO RSA Domain Validation Secure Server CA 2
NotBefore:  2019-08-23 09:00:00 +0900 JST
NotAfter:   2020-03-01 08:59:59 +0900 JST
CommonName: ssl509631.cloudflaressl.com
SANs:       [ssl509631.cloudflaressl.com *.cloudflaressl.com cloudflaressl.com]
Error:

# Get information of the certificate using ECDSA signature/public key algorithm.
$ cert -cipher TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305 cloudflaressl.com
DomainName: cloudflaressl.com
IP:         104.20.48.142
Port:       443
Issuer:     COMODO ECC Domain Validation Secure Server CA 2
NotBefore:  2019-08-23 09:00:00 +0900 JST
NotAfter:   2020-03-01 08:59:59 +0900 JST
CommonName: ssl509632.cloudflaressl.com
SANs:       [ssl509632.cloudflaressl.com *.cloudflaressl.com cloudflaressl.com]
Error:

If you specify a cipher suite, the maximum TLS version used is limited to TLS1.2. This is because if the server supports TLS1.3, the specified cipher suite is ignored and communication is performed using TLS1.3. This eliminates the meaning of specifying a cipher suite and confuses us. This specification will change when the cipher suite for Tls1.3 becomes configurable in Go.

License

MIT

Author

genkiroid

Documentation

Index

Examples

Constants

This section is empty.

Variables

View Source 
var CipherSuite = ""
View Source 
var SkipVerify = false
View Source 
var TimeoutSeconds = 3
View Source 
var UTC = false

Functions

func SetUserTempl 

func SetUserTempl(templ string) error

func SplitHostPort 

func SplitHostPort(hostport string) (string, string, error)

Types

type Cert 

type Cert struct {
	DomainName string   `json:"domainName"`
	IP         string   `json:"ip"`
	Port       string   `json:"port"`
	Issuer     string   `json:"issuer"`
	CommonName string   `json:"commonName"`
	SANs       []string `json:"sans"`
	NotBefore  string   `json:"notBefore"`
	NotAfter   string   `json:"notAfter"`
	Error      string   `json:"error"`
	// contains filtered or unexported fields
}

func NewCert 

func NewCert(hostport string) *Cert

func (*Cert) CertChain 

func (c *Cert) CertChain() []*x509.Certificate

func (*Cert) Detail 

func (c *Cert) Detail() *x509.Certificate

type Certs 

type Certs []*Cert

func NewCerts 

func NewCerts(s []string) (Certs, error)

func (Certs) JSON 

func (certs Certs) JSON() string
Example 
certs, _ := NewCerts([]string{"example.com"})

fmt.Printf("%s", certs.JSON())

Output:

[{"domainName":"example.com","ip":"127.0.0.1","port":"443","issuer":"CA for test","commonName":"example.com","sans":["example.com","www.example.com"],"notBefore":"2017-01-01 00:00:00 +0000 UTC","notAfter":"2018-01-01 00:00:00 +0000 UTC","error":""}]

func (Certs) Markdown 

func (certs Certs) Markdown() string
Example 
certs, _ := NewCerts([]string{"example.com"})

fmt.Printf("%s", certs.Markdown())

Output:

DomainName | IP | Port | Issuer | NotBefore | NotAfter | CN | SANs | Error
--- | --- | --- | --- | --- | --- | --- | --- | ---
example.com | 127.0.0.1 | 443 | CA for test | 2017-01-01 00:00:00 +0000 UTC | 2018-01-01 00:00:00 +0000 UTC | example.com | example.com<br/>www.example.com<br/> |

func (Certs) String 

func (certs Certs) String() string
Example 
certs, _ := NewCerts([]string{"example.com"})

fmt.Printf("%s", certs)

Output:

DomainName: example.com
IP:         127.0.0.1
Port:       443
Issuer:     CA for test
NotBefore:  2017-01-01 00:00:00 +0000 UTC
NotAfter:   2018-01-01 00:00:00 +0000 UTC
CommonName: example.com
SANs:       [example.com www.example.com]
Error:

Source Files

View all Source files

Directories

Path Synopsis
cmd
cert

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