# README

tlsdate

go implementation of tlsdate from ioerror, see https://github.com/ioerror/tlsdate

I copied the crypto/tls package from golang and modified it in order to add needed functionality. I added the following lines:

This code is more a proof of concept than production code. It does work fine but it is much more simplistic than the original tlsdate. Other than the original tlsdate it does NOT:

check system time on startup and sets it to COMPILE_TIME if older.
check extracted time to be sane
support of HTTP Request Timestamp extraction
run as a deamon
come with an init script

This code can set the clock but unlike the original it uses the system commands sudo and date to set the date. That also means that you might need to enter your credentials when sudo is executed, or need to configure sudo accordingly, so no password is required.

Also my commandline flags are different from the original, see USAGE.

Usage

Usage of tlsdate:
  -host="": host to connect to
  -port="443": port to connect to, on remote host
  -set=false: sets system time to tls time, when true
  -skipVerify=false: skips certificate verification, when true
  -verbose=false: verbose mode

tlsdate -host="posteo.de" -set=true

sets the system-clock to the date 'posteo.de' returned in a tls session negotiation. default port used is 443, but you can specify a port, see next example.

tlsdate -host="mail.whatever.net" -port="993" -skipVerify=true

the above command does

just print the time, does not set the clock.
not check the certificate (skipVerify).
use port 993 (IMAPS) instead of default (443/HTTPS)

The 'skipVerify' option is needed e.g. if:

remote cert is a self-signed cert.
remote cert is signed by a CA which is not listed in tlsdate-ca-roots.conf

Install

In case you have a working go environment on your system, a simple go get command will do the job.

go get github.com/scusi/tlsdate

If you have not, here is how you can: https://golang.org/doc/install.

Commits

If you want to commit to this code feel free to send me pull requests. I prefer lots of small commits that do change one thing rather than one huge commit with a dozen of changes hard to follow.