npm package to keep an eye on the expiry dates of your SSL certificates

This script connects to a given set of servers, fetches and verifies their SSL certificates, and checks the expiry dates etc. It will warn you if:

• the connection does not succeed,
• the SSL negotiation does not succeed,
• the SSL certificate does not verify,
• the SSL certificate does not match the server hostname,
• the server does not support SSL,
• the certificate uses MD5 or SHA1,
• the certificate has expired,
• any certificate in the chain has expired,
• the certificate was issued on 1st March 2018 or later and is valid for over 825 days,
• any certificate in the chain will expire soon,
• or the certificate will expire soon.

The intended use is that you will put the list of your servers using SSL in a text file, and run sslexpiry on a daily cron job to warn you if your certificates will expire soon.

Requirements

The script relies on Node.js 12 or above. You can install it with:

sudo npm install -g sslexpiry

Usage

usage: sslexpiry [-h] [-b FILENAME] [-d DAYS] [-f FILENAME] [-i]
                 [-t SECONDS] [-v] [-V] [-z]
                 [SERVER [SERVER ...]]

SSL expiry checker

Positional arguments:
  SERVER                Check the specified server.

Optional arguments:
  -h, --help            Show this help message and exit.
  -b FILENAME, --bad-serials FILENAME
                        Check the certificate serial numbers against the
                        specified file.
  -d DAYS, --days DAYS  The number of days at which to warn of expiry.
                        (default=30)
  -f FILENAME, --from-file FILENAME
                        Read the servers to check from the specified file.
  -i, --ignore-chain    Don't check other certificates in the chain
  -t SECONDS, --timeout SECONDS
                        The number of seconds to allow for server response.
                        (default=30)
  -v, --verbose         Display verbose output.
  -V, --version         Show program's version number and exit.
  -z, --exit-zero       Always return a process exit code of zero.

Files containing lists of servers can contain blank lines, and any characters from a '#' onwards are ignored as comments.

Servers specified in the files or on the command line are of the form:

hostname[@ip-address][:port][/protocol]

ip-address can be an IPv4 address (e.g. 127.0.0.1) or an IPv6 address surrounded by square brackets (eg. [::1]). If it is specified then it will be used as the IP address to connect to, instead of looking up the hostname in the DNS.

port can be a number or a standard service name (e.g. 'https'). If it is omitted then 'https' is assumed.

protocol specifies a protocol that should be followed before the SSL negotiation begins. Valid values include smtp, imap or none. If it is omitted then none is assumed, except for ports smtp or submission, where smtp is assumed, and imap, where imap is assumed.

If the -v option is specified, then output will be shown with any problems found first, then all tested servers listed with soonest expiry date first.

If the -b option is specified, the serial numbers of the certificates will be checked against those listed in the specified file(s). The file(s) should contain one serial number per line. They can contain blank lines, and any characters from a '#' onwards are ignored, as are leading or trailing whitespace. The serial numbers can be in either upper or lower case.

If the -i option is specified, only the first certificate in the chain will be checked, rather than also checking any intermediate certificates that are supplied by the server.

The process exit code will be zero if no problems were found, and non-zero otherwise, unless the --exit-zero option was specified, in which case the exit code will be zero unless there was an unexpected error.

Example server list file

# This is an example server list file

www.example.com
example.com
mail.example.com:smtp
othermail.example.com:2525/smtp # this server listens for smtp on port 2525

Example output

$ sslexpiry -vf example.conf
example.com                     Hostname/IP doesn't match certificate's altnames
www.example.com                 Certificate expiry date is 13 Mar 2018 - 6 days
othermail.example.com:2525/smtp 03 Jul 2018
mail.example.com:smtp           10 Oct 2018

History

1.12.0 (2024-02-14)

• Add a way to override the DNS and specify an IP address instead

1.11.0 (2022-08-25)

• Work-around for node-forge not supporting ECDSA
• Dependency updates mean node 12 is now required

1.10.0 (2021-09-30)

• Work-around for expiry of LetsEncrypt root certificate

1.9.0 (2021-06-12)

• Dependency updates mean node 10 is now required

1.8.0 (2020-09-25)

• Remove Symantec distrust check that is now obsolete

1.7.0 (2020-05-30)

• Check all certificates in the chain sent by the server
• Dependency updates mean node 8 is now required

1.6.0 (2020-03-04)

• Add '--bad-serials' option

1.5.0 (2019-03-08)

• Add '--exit-zero' option

1.4.0 (2018-03-20)

• Add more tests
• Improve sorting order of output
• Update package to say it works on Node 7
• Ignore '!' prefix on server names for compatibility with Python sslexpiry

1.3.0 (2018-03-18)

• Add tests and Travis integration
• Miscellaneous fixes found by the tests

1.2.0 (2018-03-12)

• Fix argument parsing by replacing commander with argparse

1.1.0 (2018-03-08)

• Check certificate is not using MD5 or SHA1

1.0.0 (2018-03-07)

• Initial release.