标签：pes mod color ESS sam var mes life payload
session是建立在Cookies基础上的技术，用于flask中存储不同请求间用户的信息，要使用session你必须设置一个secret_key，用于对Cookies进行密钥签名。如下：
from flask import Flask, render_template, session, request, redirect app = Flask(__name__) app.secret_key = ‘md_hgh58jk‘ # 使用session前需要设置该选项，用于对返回前台的cookie进行加密 @app.route(‘/login‘) def login(): # 登录成功，设置sesion，保存用户信息 if request.method == ‘POST‘: session[‘username‘] = request.form[‘username‘] session[‘password‘] = request.form[‘password‘] return redirect(‘/index‘) return render_template(‘login.html‘)
对于为什么需要使用secret_key这样的参数，源码中是使用这个当作salt进行加密，当save_session时response调用set_cookie，回写cookie。
def save_session(self, app, session, response): domain = self.get_cookie_domain(app) path = self.get_cookie_path(app) # If the session is modified to be empty, remove the cookie. # If the session is empty, return without setting the cookie. if not session: if session.modified: response.delete_cookie( app.session_cookie_name, domain=domain, path=path ) return # Add a "Vary: Cookie" header if the session was accessed at all. if session.accessed: response.vary.add("Cookie") if not self.should_set_cookie(app, session): return httponly = self.get_cookie_httponly(app) secure = self.get_cookie_secure(app) samesite = self.get_cookie_samesite(app) expires = self.get_expiration_time(app, session) val = self.get_signing_serializer(app).dumps(dict(session)) response.set_cookie( app.session_cookie_name, val, expires=expires, httponly=httponly, domain=domain, path=path, secure=secure, samesite=samesite, )
上面的val就是通过secret参数加密后的结果，写入cookie。完整的源码（from flask import session）如下：
class SecureCookieSessionInterface(SessionInterface): """The default session interface that stores sessions in signed cookies through the :mod:`itsdangerous` module. """ #: the salt that should be applied on top of the secret key for the #: signing of cookie based sessions. salt = "cookie-session" #: the hash function to use for the signature. The default is sha1 digest_method = staticmethod(hashlib.sha1) #: the name of the itsdangerous supported key derivation. The default #: is hmac. key_derivation = "hmac" #: A python serializer for the payload. The default is a compact #: JSON derived serializer with support for some extra Python types #: such as datetime objects or tuples. serializer = session_json_serializer session_class = SecureCookieSession def get_signing_serializer(self, app): if not app.secret_key: return None signer_kwargs = dict( key_derivation=self.key_derivation, digest_method=self.digest_method ) return URLSafeTimedSerializer( app.secret_key, salt=self.salt, serializer=self.serializer, signer_kwargs=signer_kwargs, ) def open_session(self, app, request): s = self.get_signing_serializer(app) if s is None: return None val = request.cookies.get(app.session_cookie_name) if not val: return self.session_class() max_age = total_seconds(app.permanent_session_lifetime) try: data = s.loads(val, max_age=max_age) return self.session_class(data) except BadSignature: return self.session_class() def save_session(self, app, session, response): domain = self.get_cookie_domain(app) path = self.get_cookie_path(app) # If the session is modified to be empty, remove the cookie. # If the session is empty, return without setting the cookie. if not session: if session.modified: response.delete_cookie( app.session_cookie_name, domain=domain, path=path ) return # Add a "Vary: Cookie" header if the session was accessed at all. if session.accessed: response.vary.add("Cookie") if not self.should_set_cookie(app, session): return httponly = self.get_cookie_httponly(app) secure = self.get_cookie_secure(app) samesite = self.get_cookie_samesite(app) expires = self.get_expiration_time(app, session) val = self.get_signing_serializer(app).dumps(dict(session)) response.set_cookie( app.session_cookie_name, val, expires=expires, httponly=httponly, domain=domain, path=path, secure=secure, samesite=samesite, )
标签：pes mod color ESS sam var mes life payload
原文地址：https://www.cnblogs.com/shenjianping/p/13236920.html
