Is it secure to hash a password before using it in an application to increase password entropy?
Does this practice increase entropy when a PBKDF is used in the application itself or does the PBKDF itself increase the password entropy?
If a random password is hashed with md5 will the output provide a 128 bit entropy?
EDIT: It is meant to use the result of the hash function as a password for cryptographic functions and applications like AES-256, email and access to computer systems.
The procedure used will be password -> hash of password -> application
EDIT 2: E.g if an email application requests a password during registration, the intended password will be hashed locally before being provided to it.