为什么check_password_hash函数返回false？使用Flask，SQLite3和Werkzeug

问题描述

我正在尝试使用Flask，Werkzeug和sqlite创建一个基本的登录功能。用户可以注册，并且密码的哈希存储在sqlite数据库中，尽管当我尝试使用正确的密码登录时，check_password_hash返回false。

当前，我正在将用户提供的密码与存储在sqlite数据库中的相关哈希进行比较，该哈希是在用户注册时使用generate_password_hash创建的。我已经阅读了Werkzeug文档，但找不到任何解决方案。

也许这与generate_password_hash永远不会两次输出相同的哈希值有关？尽管我认为check_password_hash可以解决该问题？

代码如下：

@app.route("/register",methods=["GET","POST"])
def register():
    """Register user"""
    if request.method == "GET":
        return render_template("register.html")
    if request.method == "POST":
            with sqlite3.connect("finance.db") as conn:
                cur = conn.cursor() 
                username = request.form.get("username")
                password = request.form.get("password")
                confirm_password = request.form.get("confirm-password")
                hash_value = generate_password_hash(password)
                cur.execute("SELECT * FROM users WHERE username=?",(username,))
                valid_username = cur.fetchone()
                
                # Check input and format: Username already taken? Username entered? Password entered? passwords match?
                if valid_username:
                    return ("Username not available")
                if not username:
                    return("Please enter a username")
                elif not password:
                    return("Please enter a password")
                elif not confirm_password:
                    return("Please confirm your password")
                elif password != confirm_password:
                    return ("Passwords do not match")
                else:
                    cur.execute("INSERT INTO users (username,hash) VALUES (?,?)",hash_value))
                    return redirect("/")



@app.route("/login","POST"])
def login():
    """Log user in"""

    # Forget any user_id
    session.clear()

    # User reached route via POST (as by submitting a form via POST)
    if request.method == "POST":

        # Ensure username was submitted
        if not request.form.get("username"):
            return apology("must provide username",403)

        # Ensure password was submitted
        elif not request.form.get("password"):
            return apology("must provide password",403)
# User login
# Query database for username and hash
        with sqlite3.connect("finance.db") as conn:
            cur = conn.cursor()
            username_field = request.form.get("username")
            cur.execute("SELECT username FROM users WHERE username = ?",(username_field,))
            username = cur.fetchall()
            cur.execute("SELECT hash FROM users WHERE username = ?",))
            pwhash = cur.fetchone()

            # Ensure username exists and password is correct           
            if len(username) != 1 or not check_password_hash(pwhash,request.form.get("password")):
                print(check_password_hash(pwhash,request.form.get("password")))
                return apology("invalid username and/or password",403)
            return redirect("/")

    # User reached route via GET (as by clicking a link or via redirect)
    else:
        return render_template("login.html")

在此先感谢您的帮助。

解决方法

啊哈！解决了。语法错误，pwhash`是一个元组，因为那是fetchone（）返回的，所以它必须是check_password_hash（pwhash [0]，request.form.get（“ password”）））非常感谢您的支持。我没有想到要单独测试check_password_hash函数，这样做使我意识到我正在使用元组。干杯@JanL。祝你有美好的一天。

flask python werkzeug