[Icecast] Source can't connect to Icecast with SSL enabled

[dtouch3d completely]

Hello,

I have liquidsoap streaming to icecast with url authentication and
everything works as it should. However, I enabled SSL in icecast to
enhance security and now the source doesn't connect.

In the error.log I see

    [2015-01-14  11:49:11] DBUG slave/_slave_thread checking master stream list
    [2015-01-14  11:49:13] DBUG client/client_read_bytes reading from
connection has failed
    [2015-01-14  11:49:13] DBUG client/client_destroy Called to
destory client 0x7f69f00fcbd0

and in the liquidsoap log

    2015/01/14 11:51:29 [chr_80s:3] Connecting mount stream for
source at localhost...
    2015/01/14 11:51:29 [chr_80s:2] Connection failed: could not read
data from host: Connection reset by peer in read()

In icecast.xml

  <listen-socket>
      <port>18042</port>
      <ssl>1</ssl>
  </listen-socket>
  ...
  <paths>
      <ssl-certificate>/usr/local/share/icecast/icecast.pem</ssl-certificate>
  </paths>

This only happens if I enable SSL. Without it everything works fine.
I thought SSL had nothing to do with the source authentication. The
source password is correct. Is this normal ?

Thank you very much in advance.