Securing Adobe Acrobat Connect Pro with Stunnel (Alternative to using OpenSSL)


In Adobe Acrobat Connect 7, 7.1, 7.2, 7.3, or C7.5 (licensed server only), you configured OpenSSL and sometimes experience Meeting disconnections or refreshing issues. 


A robust solution is to use Stunnel in lieu of OpenSSL. You can switch from OpenSSL to Stunnel in two ways:  

  • Offload SSL to a hardware device.
  • Install Stunnel and let Stunnel handle the SSL encryption and decryption.
  1. Download the Stunnel windows installer from

  2. Install Stunnel on the same box as Acrobat Connect.  

Assuming Software SSL was already installed:

  1. Roll back all software SSL entries in the adaptor.xml file and the Vhost file.  
  2. Leave the custom.ini as is.
  3. Copy the certs and key files to the root of the Stunnel install. 
  4. Rename the stunnel.conf file in the root install directory of Stunnel and create a new stunnel.conf file containing the following (assuming application and meeting SSL): 

; Protocol version (all, SSLv2, SSLv3, TLSv1)

sslVersion = all

; Some performance tunings


socket = l:TCP_NODELAY=1

socket = r:TCP_NODELAY=1




; Service-level configuration (you can put as many of these as you want in here)


; incoming vip for https (to secure Web)

; ip address of the server with stunnel on it (can be on same server as Acrobat Connect)

; listens on port 443


; ip of the connect server

; send the unecrypted request to port 8443

connect = <APPLICATION SERVER IP>:8443

;  Certificate information for Acrobat Connect. 

;  This assumes you put the cert and key in the root folder of Stunnel

cert = CertificateNameHere.pem

key = CerificateKeyNameHere.pem


; incoming vip for fms (to secure Meeting)

accept = <MEETING SERVER IP>:443

; ip of the fms server 

; Send unencrypted request to 1935

connect = <MEETING SERVER IP>:1935

;  Certificate information for Acrobat Connect Meetings. 

;  This assumes you put the cert and key in the root folder of Stunnel

cert = CertificateNameHere.pem

key = CerificateKeyNameHere.pem  

  1. From the Start / Programs Menu, find Stunnel and select "Install Service".

    If you have a passphrase on your private key, remove it.
  2. Start stunnel.  
  3. Restart the Acrobat Connect Services.  

Additional Information

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