; Sample stunnel configuration file for Unix by Michal Trojnara 1998-2025
; Some options used here may be inadequate for your particular configuration
; This sample file does *not* represent stunnel.conf defaults
; Please consult the manual for detailed description of available options

; **************************************************************************
; * Global options                                                         *
; **************************************************************************

; It is recommended to drop root privileges if stunnel is started by root
;setuid = stunnel4
;setgid = stunnel4

; PID file is created inside the chroot jail (if enabled)
;pid = /var/run/stunnel.pid

; Debugging stuff (may be useful for troubleshooting)
;foreground = yes
;debug = info
;output = /var/log/stunnel.log

; Enable FIPS 140-2 mode if needed for compliance
;fips = yes

; The pkcs11 engine allows for authentication with cryptographic
; keys isolated in a hardware or software token
; MODULE_PATH specifies the path to the pkcs11 module shared library,
; e.g. softhsm2.dll or opensc-pkcs11.so
; Each section using this feature also needs the "engineId = pkcs11" option
;engine = pkcs11
;engineCtrl = MODULE_PATH:/usr/lib/softhsm/libsofthsm2.so
;engineCtrl = PIN:1234

; **************************************************************************
; * Service defaults may also be specified in individual service sections  *
; **************************************************************************

; Enable support for the insecure SSLv3 protocol
;options = -NO_SSLv3

; These options provide additional security at some performance degradation
;options = SINGLE_ECDH_USE
;options = SINGLE_DH_USE

; **************************************************************************
; * Include all configuration file fragments from the specified folder     *
; **************************************************************************

;include = /etc/stunnel/conf.d

; **************************************************************************
; * Service definitions (remove all services for inetd mode)               *
; **************************************************************************

; ***************************************** Example TLS client mode services

; The following examples use /etc/ssl/certs, which is the common location
; of a hashed directory containing trusted CA certificates.  This is not
; a hardcoded path of the stunnel package, as it is not related to the
; stunnel configuration in /etc/stunnel/.

[gmail-pop3]
client = yes
accept = 127.0.0.1:110
connect = pop.gmail.com:995
verifyChain = yes
CApath = /etc/ssl/certs
checkHost = pop.gmail.com
OCSPaia = yes

[gmail-imap]
client = yes
accept = 127.0.0.1:143
connect = imap.gmail.com:993
verifyChain = yes
CApath = /etc/ssl/certs
checkHost = imap.gmail.com
OCSPaia = yes

[gmail-smtp]
client = yes
accept = 127.0.0.1:25
connect = smtp.gmail.com:465
verifyChain = yes
CApath = /etc/ssl/certs
checkHost = smtp.gmail.com
OCSPaia = yes

; Encrypted HTTP proxy authenticated with a client certificate
; located in a cryptographic token
;[example-pkcs11]
;client = yes
;accept = 127.0.0.1:8080
;connect = example.com:8443
;engineId = pkcs11
;cert = pkcs11:token=MyToken;object=MyCert
;key = pkcs11:token=MyToken;object=MyKey

; ***************************************** Example TLS server mode services

;[pop3s]
;accept  = 995
;connect = 110
;cert = /etc/stunnel/stunnel.pem

;[imaps]
;accept  = 993
;connect = 143
;cert = /etc/stunnel/stunnel.pem

; Either only expose this service to trusted networks, or require
; authentication when relaying emails originated from loopback.
; Otherwise the following configuration creates an open relay.
;[ssmtp]
;accept  = 465
;connect = 25
;cert = /etc/stunnel/stunnel.pem

; TLS front-end to a web server
;[https]
;accept  = 443
;connect = 80
;cert = /etc/stunnel/stunnel.pem
; "TIMEOUTclose = 0" is a workaround for a design flaw in Microsoft SChannel
; Microsoft implementations do not use TLS close-notify alert and thus they
; are vulnerable to truncation attacks
;TIMEOUTclose = 0

; Remote shell protected with PSK-authenticated TLS
; Create "/etc/stunnel/secrets.txt" containing IDENTITY:KEY pairs
;[shell]
;accept = 1337
;exec = /bin/sh
;execArgs = sh -i
;PSKsecrets = /etc/stunnel/secrets.txt

; Non-standard MySQL-over-TLS encapsulation connecting the Unix socket
;[mysql]
;cert = /etc/stunnel/stunnel.pem
;accept = 3307
;connect = /run/mysqld/mysqld.sock

; vim:ft=dosini
