Please read this answer for detailed information on password attributes.
If you mean the original password contents, then no. The passwords are hashed using the hashing algorithm as defined in the modeler, so there is no way in which the original password can be retrieved after a commit.
What do you mean? Do you wish to get the 'unhashed' version of the password or do you wish to save a 'normal' string into an attribute of type Hashstring?
If you mean the last option, then you can simply change the object that has an attribute of type 'hashstring' and set the value of a 'normal' string. If you mean the first option, then it is not possible. If you want to compare hasstrings you can use something like this: