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<FAQ> <4.x Man Page> <3.x Man Page> <Installing> <Running> <Arguments> <Other Applications> <Certificates> <Miscellany> <Terminology> <Troubleshooting>

Stunnel FAQ: Index

Frequently Asked Questions

The purpose of this FAQ is to provide answers to questions often asked about Stunnel. You can reach each section via the links above, or the table of contents below.

If you have a question that isn't answered here, you can ask online via the Stunnel mailing list. Information about the mailing list, as well as the data you should send with your problems, is available on the support page.

Index

Stunnel-4.08 Man Page
- NAME
- SYNOPSIS
- DESCRIPTION
- OPTIONS
- CONFIGURATION FILE
- GLOBAL OPTIONS
- SERVICE-LEVEL OPTIONS
- RETURN VALUE
- EXAMPLES
- FILES
- BUGS
- RESTRICTIONS
- NOTES
- INETD MODE
- CERTIFICATES
- RANDOMNESS
- SEE ALSO
- AUTHOR

Stunnel-3.26 Man Page

1. NAME

2. SYNOPSIS

3. DESCRIPTION

4. OPTIONS

5. EXAMPLES

6. ENVIRONMENT

7. CERTIFICATES

8. RANDOMNESS

9. LIMITATIONS

10. SEE ALSO

11. AUTHOR

Compiling/Installing Stunnel
- How do I use the pre-compiled Windows binaries?
- How do I compile stunnel from sources?
- Configure options.

Running Stunnel
- Running stunnel in inetd mode, Stunnel 3.x
- Running stunnel in inetd mode, Stunnel 4.x
- Running stunnel in daemon mode
- Running stunnel with TCP wrappers
- Stopping stunnel
- Running stunnel as a service under windows

Stunnel Command Line Arguments
- Important Note
- Stunnel Arguments

Stunnel and Other Applications
- Can I forward UDP services over stunnel?
- Can I use stunnel to communicate across a firewall?
- Can I use stunnel to securely connect two subnets across the Internet?
- Can I use stunnel to protect [insert random protocol here]?

Using Certificates with Stunnel
- Quick certificate overview.
- What's a certificate?
- Do I need a valid certificate?
- Genererating the stunnel private key (pem).
- But I don't have the openssl binary!
- How can I get rid of a passphrase on my key?
- Problems with a self-signed certificate.
- Do I need to have a Certificate Authority sign my key?
- How can I have my key signed by a CA?
- Can I set up my own CA instead?
- How does stunnel check certificates?
- Where do I put all these certificates?
- Where can I get a copy of official CA certificates?
- How do I import/trust a certificate into Outlook/Outlook Express/IE/etc
- How do I convert a PKCS12 certificate to PEM form?
- Other useful web pages (not necessarily stunnel specific)
- Setting up your own CA -- Useful URLs

The Ubiquitous Miscellaneous Section
- What are the offical SSL ports?
- How do I know which encryption ciphers are available?
- How can I delay DNS lookups until connect time?
- How can I convert a certificate from der format (.cer) to PEM format?

Terminology
- Session Cache

Troubleshooting
- Upgrading from 3.x to 4.x
  - I want to upgrade to 4.x, but I can't get a working config file!
- Common Compilation Problems
  - I'm having trouble compiling Stunnel on my Immunix box or with StackGuard/FormatGuard
  - "Couldn't find your SSL library installation dir" when running configure
  - Too few arguments to function `PEM_read_bio_DHparams'
  - Errors about 'ssl.h: No such file or directory'
  - configure isn't finding my TCP Wrapper installation
  - The files I'm downloading are corrupted / wrong size!
- What to do when Stunnel fails
- I don't have the openssl binary / Can't make stunnel.pem!
- Problems running Stunnel
  - When I run Stunnel 4.x, it just sits there, it doesn't listen for requests!
  - I get an error about opening /dev/cryptonet
  - I get the error 'Wrong permissions on stunnel.pem'
  - SSL_accept: error:00000000::lib(0) :func(0) :reason(0)
  - FTP over Stunnel won't work
  - Stunnel isn't working with Windows with strong crypto.
  - Stunnel isn't working with Windows 2000 (Outlook Express).
  - How do I configure Outlook to use SSL?
  - I can't type anything when running Stunnel in client mode on Windows.
  - Stunnel doesn't seem to be reusing session IDs in client mode.
  - Stunnel 3.8 or earlier fails with a "PRNG not seeded" error message.
  - Stunnel 3.8 or greater fails with a "PRNG not seeded" error message.
  - Why won't transparent mode work?
  - Secure Password Authentication error with Outlook and POP
  - Help, I've got zombies!
  - Help! I'm running on Linux with threads, but Stunnel keeps forking off processes anyway!
  - I'm trying to use Stunnel as a pipe, but it doesn't seem to work!
  - I'm having trouble with MySQL and Stunnel
  - Stunnel hangs for a while accepting connections
  - Stunnel is complaining that there are too many open files and is refusing new connections
  - My connections are slow, slow, slow
  - Are there any special problems with Stunnel and IE?
  - I'm running out of processes/file descriptors
  - The logs aren't going where they should be in Digital Unix
  - I can't understand these networking errors on my Windows machine
  - TCP Wrappers aren't working right
  - My web browser can't talk to Stunnel
  - Problems tunneling telnet over Stunnel with AIX
  - Eudora keeps saying "error reading network"
  - I'm running Stunnel 3.x as a service, but it dies on logoff