python

# coding: utf-8 
# 查询域名证书到期情况

import re
import time
import subprocess
from datetime import datetime
from io import StringIO

def main(domain):
  f = StringIO()
  comm = f"curl -Ivs https://{domain} --connect-timeout 10"

  result = subprocess.getstatusoutput(comm)
  f.write(result[1])

  m = re.search('start date: (.*?)\n.*?expire date: (.*?)\n.*?common name: (.*?)\n.*?issuer: CN=(.*?)\n', f.getvalue(), re.S)
  start_date = m.group(1)
  expire_date = m.group(2)
  common_name = m.group(3)
  issuer = m.group(4)

  # time 字符串转时间数组
  start_date = time.strptime(start_date, "%b %d %H:%M:%S %Y GMT")
  start_date_st = time.strftime("%Y-%m-%d %H:%M:%S", start_date)
  # datetime 字符串转时间数组
  expire_date = datetime.strptime(expire_date, "%b %d %H:%M:%S %Y GMT")
  expire_date_st = datetime.strftime(expire_date,"%Y-%m-%d %H:%M:%S")

  # 剩余天数
  remaining = (expire_date-datetime.now()).days

  print ('域名:', domain)
  print ('通用名:', common_name)
  print ('开始时间:', start_date_st)
  print ('到期时间:', expire_date_st)
  print (f'剩余时间: {remaining}天')
  print ('颁发机构:', issuer)
  print ('*'*30)

  time.sleep(0.5)

if __name__ == "__main__":
  domains = ['www.baidu.com'] 
  for domain in domains:
    main(domain)

结果示例：

域名: www.baidu.com
通用名: baidu.com
开始时间: 2019-05-09 01:22:02
到期时间: 2020-06-25 05:31:02
剩余时间: 82天
颁发机构: GlobalSign Organization Validation CA – SHA256 – G2,O=GlobalSign nv-sa,C=BE

shell

# 填写需要监控的域名和端口号
domain="${1:-www.baidu.com}"
port="${2:-443}"

# 获取证书信息
cert_info=$(echo | openssl s_client -servername $domain -connect $domain:$port 2>/dev/null | openssl x509 -noout -dates)

# 提取证书有效期的起止日期
start_date=$(echo "$cert_info" | grep -i "notBefore" | awk -F '=' '{print $2}')
end_date=$(echo "$cert_info" | grep -i "notAfter" | awk -F '=' '{print $2}')

# 将日期转换为时间戳
start_timestamp=$(date -d "$start_date" +%s)
end_timestamp=$(date -d "$end_date" +%s)
current_timestamp=$(date +%s)

# 计算剩余天数
remaining_days=$(( ($end_timestamp - $current_timestamp) / 86400 ))

# 打印证书有效期信息
echo "域名: $domain"
echo "起始日期: $start_date"
echo "结束日期: $end_date"
echo "剩余天数: $remaining_days"