User Login system, written by Flask,sqlite,hmac

#-*-Coding:utf-8-*-
"""
Created on Sat June 30 10:56:19 2018

@author: Lewisliu
"""

From flaskImport Flask
From flaskImport Request
Import Sqlite3
Import HMAC


#def HMAC_SHA1 (Key, s):
# return Hmac.new (Key.encode (' Utf-8 '), S.encode (' Utf-8 '), ' MD5 '). Hexdigest ()


App = Flask (__name__)



@app. Route (‘/‘,methods=[' GET ',' POST '])
DefHome ():
 Return' 

@app. Route ('/signin ',methods=[' GET '])
DefSignin_form ():
 Return"' <form action="/signin "method=" POST ">
<p>model<input name= "Model" > (enroll/login/exit) </p>
<p>username<input name= "username" ></p>
<p>password<input name= "password" type= "password" ></p>
<p><button type= "Submit" >Submit</button></p>
</form> "


@app. Route ('/signin ',methods=[' POST '])
DefSignin ():
 # The form content needs to be read from the Request object:
conn = Sqlite3.connect (' User_flask.db ')
cursor = Conn.cursor ()
 Try
Cursor.execute (' CREATE table Userpass (name varchar (primary key, password varchar (20)) ')
 ExceptExceptionAsE:
 Pass
If request.form[' Model ']==' Exit ':
Conn.close ()
 Return'  Elif request.form[' Model ']==' Enroll ':
Flag = Cursor.execute ("SELECT name from Userpass where name= '%s '"% request.form[' username ']). Fetchone ()
 If flag:
 Return"' <form action="/signin "method=" POST ">
<p>name exit!</p>
<p>model<input name= "Model" > (enroll/login/exit) </p>
<p>username<input name= "username" ></p>
<p>password<input name= "password" type= "password" ></p>
<p><button type= "Submit" >Submit</button></p>
</form> "
 Else
Key =' Liu '# '. Join ([Chr (Random.randint (122)) for I in range (20)])
Password = hmac.new (Key.encode (' Utf-8 '), request.form[' Password '].encode (' Utf-8 '),' MD5 '). Hexdigest ()
Cursor.execute ("INSERT into Userpass (name, password) VALUES ('%s ', '%s ')"% (request.form[' Username '], password))
Conn.commit ()
 Return"' <form action="/signin "method=" POST ">
<p>you Enroll Successful!</p>
<p>model<input name= "Model" > (enroll/login/exit) </p>
<p>username<input name= "username" ></p>
<p>password<input name= "password" type= "password" ></p>
<p><button type= "Submit" >Submit</button></p>
</form> "
 Elif request.form[' Model ']==' Login ':
Key =' Liu '
Password = hmac.new (Key.encode (' Utf-8 '), request.form[' Password '].encode (' Utf-8 '),' MD5 '). Hexdigest ()
Flag = Cursor.execute ("SELECT name and password from userpass where name = '%s ' and password= '%s '"% (request.form[' Username '], password)). Fetchone ()
 If flag:
 Return"' <form action="/signin "method=" POST ">
<p>wellcome!</p>
<p>model<input name= "Model" > (enroll/login/exit) </p>
<p>username<input name= "username" ></p>
<p>password<input name= "password" type= "password" ></p>
<p><button type= "Submit" >Submit</button></p>
</form> "
 Else
 Return"' <form action="/signin "method=" POST ">
<p>bad Username or password!</p>
<p>model<input name= "Model" > (enroll/login/exit) </p>
<p>username<input name= "username" ></p>
<p>password<input name= "password" type= "password" ></p>
<p><button type= "Submit" >Submit</button></p>
</form> "
 else: 
 return "<form action="/signin "method=" POST "
  <p> Model Wrong!</p> 
  <p>model<input name= "model" > (enroll/login/ Exit) </p> 
  <p>username<input name= "username" ></P> 
 Span style= "COLOR: #6a8759" > <p>password<input name= "password" type= "password" ></P> 
  <p><button type= "Submit" >SUBMIT</BUTTON></P> 
  </form> "
  
  
 if __name__ =  "__main __ ': 
 App.run ()              

User Login system, written by Flask,sqlite,hmac