[[!comment format=mdwn
 username="guilhem"
 avatar="https://seccdn.libravatar.org/avatar/86d6cb4bde1ef88730b14ccad0414c28"
 subject="Unreproducible here (Firefox ESR 45.0.1)"
 date="2016-04-07T16:32:37Z"
 content="""
Keys are properly pinned here 

  1. Close the browser
  2. Remove all mentions of `fripost.org` in `~/.mozilla/firefox/<profile>/SiteSecurityServiceState.txt`:

        ~$ sed -i -r '/^(\S+\.)?fripost\.org:/d' ~/.mozilla/firefox/<profile>/SiteSecurityServiceState.txt
        
  3. Start the browser (without HSTS or HPKP knowledge for `fripost.org` or any of its subdomains)
  4. Open `https://mail.fripost.org/` in a new tab
  5. (After waiting a few seconds to let firefox flush the data.)  The 
     HSTS policy and the two pins appear in the file:
     
        ~$ grep -E '^(\S+\.)?fripost\.org:' ~/.mozilla/firefox/<profile>/SiteSecurityServiceState.txt
        mail.fripost.org:HSTS   0   16898   1475812232563,1,1
        mail.fripost.org:HPKP   0   16898   1460047832565,1,0,SHfniMEapxeYo5YT/2jP+n+WstNaYghDMhZUadLlPDk=/Tt92H3ZkfEW1/AOCoGVm1TxZl7u4c+tIBnuvAc7d5w=
        
     There is no warning in the log, either.
 
The root CA (*DST Root CA X3*) appear in Firefox's CA store as a \"Builtin Object Token\", while the intermediate CA (*Let's Encrypt Authority X3*) is supplied by the server and automatically stored by Firefox as a \"Software Security Device\".

Do you have default settings for the `security.cert_pinning.*` [tunables](https://wiki.mozilla.org/SecurityEngineering/Public_Key_Pinning)?

    security.cert_pinning.enforcement_level = 1
    security.cert_pinning.process_headers_from_non_builtin_roots = false

Please also verify that you have no weird non-default tunables for `security.*`.
"""]]