flask-bcrypt – ValueError: Invalid salt

Issue

I was finishing up a simple user login with Flask and flask-Bcrypt. However, when trying to login with a user that is stored in my database, I keep getting this error

ValueError: Invalid salt

models.py

class User(db.Model):

    __tablename__ = "users"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String, nullable=False)
    email = db.Column(db.String, nullable=False)
    password = db.Column(db.String, nullable=False)
    posts = db.relationship("Post", backref="author", lazy="dynamic")

    def __init__(self, name, email, password):
        self.name = name
        self.email = email
        self.password = bcrypt.generate_password_hash(password)

    def __repr__(self):
        return '<User {}>'.format(self.name)

views.py

@app.route("/login", methods=["GET", "POST"])
def login():
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter(User.name == form.username.data).first()
        if user and bcrypt.check_password_hash(user.password, form.password.data):
            flash("you were just logged in!")
            login_user(user)
            return redirect(url_for("home"))
        else:
            flash("bad username or password")
    return render_template("login.html", form=form)

forms.py

class LoginForm(Form):
    username = StringField('username', validators=[DataRequired()])
    password = PasswordField('password', validators=[DataRequired()])

Solution

Basically you would like to encode your data before the hash: password.encode('utf-8'). If it comes as unicode it may raise errors.
Have a look here also: https://github.com/maxcountryman/flask-bcrypt/issues/9

Answered By – user5732545

This Answer collected from stackoverflow, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0