Question

I am trying to use openssl to get a certificate, and it seems to keep hanging. I have done a lot of research but not all of the available options seem to work on Windows.

openssl s_client -showcerts -connect google.com:443 > cert.txt

I have tried this:

openssl s_client -connect xyz:443 < quit.txt > cert.txt

Where quit.txt contains “quit\n”
from http://bytes.com/topic/php/answers/8802-automate-openssl-s_client-command-batch-php-script

That did not work. I also looked at Openssl s_clinet -connect scripting. Force quit help

I have also tried -prexit

I have also looked into this as well and can’t get it working:
https://serverfault.com/questions/139728/how-to-download-ssl-certificate-from-a-website

I was doing so well! I managed to do something that I thought would be impossible and a simple thing like this bug managed to stop me for the time being 🙁

Answer 1

It looks like some OpenSSL distributions for Windows are expecting an additional keypress, independant of standard input. Quit.txt gets correctly piped into openssl’s STDIN (the server receives QUIT command), but nothing happens until you press any key.

This problem does not exist in Cygwin’s version of OpenSSL. Unfortunatly base installation of Cygwin takes about 100 MB of disk space, but you can try to extract only openssl.exe and required libraries.

This method works:

echo QUIT | c:\cygwin\bin\openssl.exe s_client -showcerts -connect google.com:443 > cert.txt