/// <summary>
/// Before cache access
/// </summary>
/// <param name="args">Callback parameters from MSAL</param>
internal void BeforeAccessNotification(TokenCacheNotificationArgs args)
{
_logger.LogInformation($"Before access");
_logger.LogInformation($"Acquiring lock for token cache");
// OK, we have two nested locks here. We need to maintain a clear ordering to avoid deadlocks.
// 1. Use the CrossPlatLock which is respected by all processes and is used around all cache accesses.
// 2. Use _lockObject which is used in UnregisterCache, and is needed for all accesses of _registeredCaches.
CacheLock = CreateCrossPlatLock(_storageCreationProperties);
_logger.LogInformation($"Before access, the store has changed");
var cachedStoreData = CacheStore.ReadData();
_logger.LogInformation($"Read '{cachedStoreData?.Length}' bytes from storage");
lock (_lockObject)
{
try
{
_logger.LogInformation($"Deserializing the store");
args.TokenCache.DeserializeMsalV3(cachedStoreData, shouldClearExistingCache: true);
}
catch (Exception e)
{
_logger.LogError($"An exception was encountered while deserializing the {nameof(MsalCacheHelper)} : {e}");
_logger.LogError($"No data found in the store, clearing the cache in memory.");
// Clear the memory cache
Clear();
throw;
}
}
}
/// <summary>
/// Extracts the token cache data from the persistent store
/// </summary>
/// <returns>an UTF-8 byte array of the unencrypted token cache</returns>
/// <remarks>This method should be used with care. The data returned is unencrypted.</remarks>
public byte[] LoadUnencryptedTokenCache()
{
using (CreateCrossPlatLock(_storageCreationProperties))
{
return(CacheStore.ReadData(ignoreExceptions: false));
}
}
