go 判断 https ssl 证书是否过期

package main

import (
    "crypto/tls"
    "fmt"
    "time"
)

func main() {
    conn, err := tls.Dial("tcp", "blog.umesh.wtf:443", nil)
    if err != nil {
        panic("Server doesn't support SSL certificate err: " + err.Error())
    }

    err = conn.VerifyHostname("blog.umesh.wtf")
    if err != nil {
        panic("Hostname doesn't match with certificate: " + err.Error())
    }
    expiry := conn.ConnectionState().PeerCertificates[0].NotAfter
    fmt.Printf("Issuer: %s\nExpiry: %v\n", conn.ConnectionState().PeerCertificates[0].Issuer, expiry.Format(time.RFC850))
}

参考自 freecodecamp