dynalogin can be found on www.dynalogin.org, the Android App is on Google Play and on F-Droid. However the documentation is little bit sparse.

The location of the filesystem datasource as packaged with debian is /var/dynalogin-passwd

The format of the filesystem datasource for initialiation is

testuser:HOTP:12345678901234567890:0:0:0:0:0:0

where 12345678901234567890 is the secret.

The Android App seems to provides HOTP passwords, not TOTP.

It seems to me, for the filesystem data source, there is a bug in the code:

--- libdynalogin/datasources/fs/fs_ds.c 2013/02/19 22:08:59     1.1
+++ libdynalogin/datasources/fs/fs_ds.c 2014/03/14 13:45:45
@@ -115,6 +126,7 @@
        user_data->last_success=atol(_substrings[field++]);
        user_data->last_attempt=atol(_substrings[field++]);
        user_data->last_code=_substrings[field++];
+       return APR_SUCCESS;
 }