Você pode usar o icecast2 para esse fim sem especificar o uso da autenticação.
Na documentação :
nome de usuário
An optional value which will set the username that a source must use to connect using this mountpoint. Do not set this value unless you are sure that the source clients connecting to the mount point can be configured to send a username other than source.
If this value is not present the default username is source.
senha
An optional value which will set the password that a source must use to connect using this mountpoint. There is also a URL based authentication method for sources that can be used instead.