a is a hashed password. b is salt.
PasswordHash specifies a hashed password and the salt for the password. Upon starting or restarting InterSystems IRIS® data platform, the stored password hash is set to PasswordHash for each enabled user account with at least one assigned role. If PasswordHash is empty, InterSystems IRIS ignores it on startup.
After setting user account passwords using PasswordHash, remove the value of PasswordHash. If you neglect to do this, PasswordHash overwrites any future password changes when you start or restart InterSystems IRIS.
The primary use for PasswordHash is to set the default password for automated deployments.
PasswordHash is not recommended for changing passwords on a deployed instance. For details about changing individual user passwords in the Management Portal, see Edit an Existing User.
For details about hashing a password and an example of using PasswordHash when deploying a container, see Authentication and Passwords in Running InterSystems Products in Containers.
Changing This Parameter
On the Startup page of the Management Portal (System Administration > Configuration > Additional Settings > Startup), in the PasswordHash row, select Edit. Paste the hash and salt for your password.
Instead of using the Management Portal, you can change PasswordHash in the Config.Startup class (as described in the class reference) or by editing the CPF in a text editor (as described in the Editing the Active CPF section of the “Introduction to the Configuration Parameter File” chapter in this book).