예제 #1
0
        /// <summary>
        /// Reads the cache data from the backend database.
        /// </summary>
        private void ReadCacheForSignedInUser(TokenCacheNotificationArgs args)
        {
            string accountId = httpContextAccesssor.HttpContext.User.GetMsalAccountId();

            if (this.InMemoryCache == null) // first time access
            {
                this.InMemoryCache = GetLatestUserRecordQuery(accountId).FirstOrDefault();
            }
            else
            {
                // retrieve last written record from the DB
                var lastwriteInDb = GetLatestUserRecordQuery(accountId).Select(n => n.LastWrite).FirstOrDefault();

                // if the persisted copy is newer than the in-memory copy
                if (lastwriteInDb > InMemoryCache.LastWrite)
                {
                    // read from from storage, update in-memory copy
                    this.InMemoryCache = GetLatestUserRecordQuery(accountId).FirstOrDefault();
                }
            }

            // Send data to the TokenCache instance
            args.TokenCache.DeserializeMsalV3((InMemoryCache == null) ? null : this.DataProtector.Unprotect(InMemoryCache.CacheBits), shouldClearExistingCache: true);
        }
        /// <summary>
        /// Raised AFTER MSAL added the new token in its in-memory copy of the cache.
        /// This notification is called every time MSAL accessed the cache, not just when a write took place:
        /// If MSAL's current operation resulted in a cache change, the property TokenCacheNotificationArgs.HasStateChanged will be set to true.
        /// If that is the case, we call the TokenCache.Serialize() to get a binary blob representing the latest cache content – and persist it.
        /// </summary>
        /// <param name="args">Contains parameters used by the MSAL call accessing the cache.</param>
        private void UserTokenCacheAfterAccessNotification(TokenCacheNotificationArgs args)
        {
            string accountId = args.Account?.HomeAccountId?.Identifier;

            if (string.IsNullOrEmpty(accountId))
            {
                accountId = httpContextAccesssor.HttpContext.User.GetMsalAccountId();
            }

            // if state changed, i.e. new token obtained
            if (args.HasStateChanged && !string.IsNullOrWhiteSpace(accountId))
            {
                if (this.InMemoryCache == null)
                {
                    this.InMemoryCache = new UserTokenCache
                    {
                        WebUserUniqueId = accountId
                    };
                }

                this.InMemoryCache.CacheBits = this.DataProtector.Protect(args.TokenCache.SerializeMsalV3());
                this.InMemoryCache.LastWrite = DateTime.Now;

                try
                {
                    // Update the DB and the lastwrite
                    this.TokenCacheDb.Entry(InMemoryCache).State = InMemoryCache.UserTokenCacheId == 0 ? EntityState.Added : EntityState.Modified;
                    this.TokenCacheDb.SaveChanges();
                }
                catch (DbUpdateConcurrencyException)
                {
                    // Record already updated on a different thread, so just read the updated record
                    this.ReadCacheForSignedInUser(args);
                }
            }
        }