internal static object GetAlgorithmFromConfig(string algorithm)
{
if (string.IsNullOrEmpty(algorithm))
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentNullException(nameof(algorithm)));
}
object algorithmObject = null;
object defaultObject = null;
Func <object> delegateFunction = null;
if (!s_algorithmDelegateDictionary.TryGetValue(algorithm, out delegateFunction))
{
lock (s_algorithmDictionaryLock)
{
if (!s_algorithmDelegateDictionary.ContainsKey(algorithm))
{
try
{
algorithmObject = CryptoConfig.CreateFromName(algorithm);
}
catch (TargetInvocationException)
{
s_algorithmDelegateDictionary[algorithm] = null;
}
if (algorithmObject == null)
{
s_algorithmDelegateDictionary[algorithm] = null;
}
else
{
defaultObject = GetDefaultAlgorithm(algorithm);
if (defaultObject != null && defaultObject.GetType() == algorithmObject.GetType())
{
s_algorithmDelegateDictionary[algorithm] = null;
}
else
{
// Create a factory delegate which returns new instances of the algorithm type for later calls.
Type algorithmType = algorithmObject.GetType();
Linq.Expressions.NewExpression algorithmCreationExpression = Linq.Expressions.Expression.New(algorithmType);
Linq.Expressions.LambdaExpression creationFunction = Linq.Expressions.Expression.Lambda <Func <object> >(algorithmCreationExpression);
delegateFunction = creationFunction.Compile() as Func <object>;
if (delegateFunction != null)
{
s_algorithmDelegateDictionary[algorithm] = delegateFunction;
}
return(algorithmObject);
}
}
}
}
}
else
{
if (delegateFunction != null)
{
return(delegateFunction.Invoke());
}
}
//
// This is a fallback in case CryptoConfig fails to return a valid
// algorithm object. CrytoConfig does not understand all the uri's and
// can return a null in that case, in which case it is our responsibility
// to fallback and create the right algorithm if it is a uri we understand
//
switch (algorithm)
{
case SHA256String:
case SecurityAlgorithms.Sha256Digest:
return(SHA256.Create());
case SecurityAlgorithms.Sha1Digest:
#pragma warning disable CA5350 // Do not use insecure cryptographic algorithm SHA1.
return(SHA1.Create());
#pragma warning restore CA5350 // Do not use insecure cryptographic algorithm SHA1.
case SecurityAlgorithms.HmacSha1Signature:
#pragma warning disable CA5350 // Do not use insecure cryptographic algorithm SHA1.
return(new HMACSHA1());
#pragma warning restore CA5350 // Do not use insecure cryptographic algorithm SHA1.
default:
break;
}
return(null);
}
public override object DoAggregatinon(Type elementType, IQueryable query, Microsoft.OData.Core.UriParser.Semantic.ApplyAggregateClause transformation, Linq.Expressions.LambdaExpression propertyToAggregateExpression, params string[] parameters)
{
throw new NotImplementedException();
}
