How to verify SSL SHA-1 Certificate Fingerprnit Signature of your mail/web server to avoid hijacking/man-in-the-middle attacks -

How to verify SSL SHA-1 Certificate Fingerprnit Signature of your mail/web server to avoid hijacking/man-in-the-middle attacks

This is especially helpful if you run your own servers.  If you are presented with an error message or warning that the signature has changed or does not match the IP/domain you are connecting to you always want to verify manually.

So your e-mail/web client will show you an SHA-1 fingerprint like this:

"Could not verify this certificate because the issuer is unkown" or other reasons such as a mismatch in IP/domain.

It will also show you the "SHA1 fingerprint".   Copy this and compare below with the results of your actual server certificate.

How to verify it against the actual certificate on your server?:

openssl x509 -fingerprint -in /pathto/your-certificate.crt -noout

SHA1 Fingerprint=CD:32:57:8A:66:18:71:87:81:B8:A5:F6:2E:52:3D:15:C5:A9:41:06

How to manually fetch the SHA1 certificate straight from the server to compare?

openssl s_client -showcerts -connect yourdomain.com:port 2>/dev/null|openssl x509 -fingerprint -noout

Conclusion

This is an important and good way to verify that you are actually talking to who you think you are and that there is no direct interception or Middleman attack.


  • How to disable Google Fonts in Wordpress
  • Unable to load dynamic library /usr/lib64/php/modules/php_openssl
  • mysqld in Linux hacked
  • W: GPG error: http://archive.debian.org squeeze Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AED4B06F473041FA NO_PUBKEY 64481591B98321F9
  • cannot mount kvm ntfs image
  • h264 DVR security camera footage cannot be played
  • dhcpd.conf how to secure so only known and allowed clients will be given dhcpd IP address leases
  • Thunderbird E-mail List Blank White but e-mails still clickable and viewable
  • css responsive images
  • responsive table without changing much code solution
  • yum how to install old obsolete packages
  • PHP Howto Store Value of Included File Output Into Variable
  • PHP Migration from 5.3 to 5.4+ and dealing with deprecated functions
  • ffmpeg vidstab to stabilize video
  • userdel user userdel: cannot lock /etc/passwd; try again later.
  • mdadm how to mount inactive array
  • How to find and mount mdadm arrays automatically
  • M2Crypto.SSL.Checker.WrongHost: Peer certificate subjectAltName does not match host, expected fedora-archive.ip-connect.vn.ua, got DNS:mirror.ip-connect.vn.ua
  • [Wed Sep 20 15:34:44 2017] [notice] suEXEC mechanism enabled (wrapper: /usr/sbin/suexec) [Wed Sep 20 15:34:44 2017] [error] Init: Unable to read server certificate from file /www/ssl-certs/server.crt [Wed Sep 20 15:34:44 2017] [error] SSL Library Err
  • linux how to answer yes to copy