PEM - http://www.stunnel.org/static/stunnel.html, search for "cert =", documented in the service options section. You need OpenSSL on the box to use Stunnel - and OpenSSL has everything you need to convert certificates between formats/containerization as needed to get your cert into PEM format. E.g., if they give you a DER-formatted certificate named "file.cer", run: openssl x509 -in file.cer -inform der -outform pem -out file.pem This link has more info on telling if your provider gave you a DER or PEM formatted cert: https://support.ssl.com/Knowledgebase/Article/View/19/0/der-vs-crt-vs-cer-vs... It also has conversion commands to use. If your provider gave you a .pfx file, then it's a pkcs#12 container, having a cert, key, and possibly CA chain in it. This link has info on exporting your certificate from such a file: http://www.sslshopper.com/article-most-common-openssl-commands.html P7c (pkcs#7) you're unlikely to see. Used for CA chains. Actually, maybe you will - yell if so, or research. -----Original Message----- From: stunnel-users [mailto:stunnel-users-bounces@stunnel.org] On Behalf Of Ben Stover Sent: Friday, October 18, 2013 3:21 AM To: Stunnel Users Subject: EXTERNAL: [stunnel-users] Which X.509 certificate types (.crt, .pem, .der .p7c) possible for stunnel and how to import them? Which X.509 certificate types (e.g. .crt, .pem, .der .p7c) are possible for stunnel? Assume I have got such a certificate as separate file (and not retrieved by OpenSSL). How do I import it into stunnel? Do I have to just copy it into (which ?) directory? Does the certifcate file name have to have a certain pattern? Or is stunnel smart enough to read and analyze the content independently from filename? Thank you Ben _______________________________________________ stunnel-users mailing list stunnel-users@stunnel.org https://www.stunnel.org/cgi-bin/mailman/listinfo/stunnel-users