Symptoms

When going to manage/add new add-ons page, this error is displayed:

The Atlassian Marketplace server is not reachable. To avoid problems when loading this page, you can disable the connection to the Marketplace server

The Confluence logs contain the following errors:

2013-10-29 14:30:17,194 WARN  [http-bio-7990-exec-5] user 870x497x1 1lzkc13 XXX.XXX.XXX.XXX,127.0.0.1 "GET /plugins/servlet/upm/marketplace HTTP/1.0" com.atlassian.upm.pac.PacClientImpl Error when querying application info from MPAC: com.atlassian.marketplace.client.MpacException: javax.net.ssl.SSLPeerUnverifiedException: peer not authenticated

Cause

The Atlassian Marketplace needs to verify the SSL connection between Confluence and itself. This occurs because the certificate is missing or has been tampered with by the local Proxy.

Resolution

To resolve this you need to manually import the certificates using the steps below:

1. Download the following certificates with the commands below and remove everything but the certificates themselves:
   

   Linux

   openssl s_client -connect marketplace.atlassian.com:443 < /dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > marketplace.atlassian.com.crt
   openssl s_client -connect plugins.atlassian.com:443 < /dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > plugins.atlassian.com.crt
   openssl s_client -connect api.media.atlassian.com:443 < /dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > api.media.atlassian.com.crt

   Windows

   openssl s_client -connect marketplace.atlassian.com:443 < NUL > marketplace.atlassian.com.crt
   openssl s_client -connect plugins.atlassian.com:443 < NUL > plugins.atlassian.com.crt
   openssl s_client -connect api.media.atlassian.com:443 < NUL > api.media.atlassian.com.crt

   After saving the certificates in Windows, edit them and delete everything before the "BEGIN CERTIFICATE" line and everything after the "END CERTIFICATE" line. This step is not required for Linux.
   
   

2. And then import them into your truststore in this order:

   keytool -import -alias marketplace.atlassian.com:443 -keystore /path/to/truststore -file /path/to/marketplace.atlassian.com.crt
   keytool -import -alias plugins.atlassian.com:443 -keystore /path/to/truststore -file /path/to/plugins.atlassian.com.crt
   keytool -import -alias api.media.atlassian.com:443 -keystore /path/to/truststore -file /path/to/api.media.atlassian.com.crt

   The trust store is located in the following directories:

   • Windows/Linux: $JAVA_HOME/jre/lib/security/cacerts
   • Mac OS (not supported): $JAVA_HOME/lib/security/cacerts

   If keytool prompts for a password, the default is 'changeit'.

Please see the following question on Atlassian Answers and Problems Connecting to the Atlassian Marketplace for further information.