PgPool fails to auth in master_slave mode
Solution, in 2 words: install latest pgpool2 from sources

Step by step solution: 


Make sure that you have pgpool2 with version 3+
Create pool_passwd with pg_md5 command
Make sure, that you have md5 in pool_hba.conf. If you have pgpool2 from deb - it will not support md5 token in pool_hba.conf