Question on MD5 authentication

I am trying to connect to machine A (192.168.1.155) from a different
machine B (192.168.1.180), with password transmitted as a MD5 string.

I have the following lines in my pg_hba.conf file.

host all all 192.168.1.180 255.255.255.1 md5

I created a database user "test_user":

create user test_user with password 'test_passwd';

In A's database, I have

select usename, passwd from pg_shadow;

usename | passwd
-----------+-------------------------------------
postgres |
pgbench |
test_user | md5c573460a3b356e4610bfae406e1d8a9f

Then I try to connect to A from B with the following:

psql -h 192.168.1.155 -U test_user template1
Password for user test_user: (I typed test_passwd)
psql: FATAL: password authentication failed for user "test_user"