/// <summary>
/// Combines the <see cref="AuthorizationPolicy"/> provided by the specified
/// <paramref name="policyProvider"/>.
/// </summary>
/// <param name="policyProvider">A <see cref="IAuthorizationPolicyProvider"/> which provides the policies to combine.</param>
/// <param name="authorizeData">A collection of authorization data used to apply authorization to a resource.</param>
/// <returns>
/// A new <see cref="AuthorizationPolicy"/> which represents the combination of the
/// authorization policies provided by the specified <paramref name="policyProvider"/>.
/// </returns>
public static async Task <AuthorizationPolicy> CombineAsync(IAuthorizationPolicyProvider policyProvider, IEnumerable <IAuthorizeData> authorizeData)
{
if (policyProvider == null)
{
throw new ArgumentNullException(nameof(policyProvider));
}
if (authorizeData == null)
{
throw new ArgumentNullException(nameof(authorizeData));
}
// Avoid allocating enumerator if the data is known to be empty
var skipEnumeratingData = false;
if (authorizeData is IList <IAuthorizeData> dataList)
{
skipEnumeratingData = dataList.Count == 0;
}
AuthorizationPolicyBuilder policyBuilder = null;
if (!skipEnumeratingData)
{
foreach (var authorizeDatum in authorizeData)
{
if (policyBuilder == null)
{
policyBuilder = new AuthorizationPolicyBuilder();
}
var useDefaultPolicy = true;
if (!string.IsNullOrWhiteSpace(authorizeDatum.Policy))
{
var policy = await policyProvider.GetPolicyAsync(authorizeDatum.Policy);
if (policy == null)
{
throw new InvalidOperationException(Resources.FormatException_AuthorizationPolicyNotFound(authorizeDatum.Policy));
}
policyBuilder.Combine(policy);
useDefaultPolicy = false;
}
var rolesSplit = authorizeDatum.Roles?.Split(',');
if (rolesSplit != null && rolesSplit.Any())
{
var trimmedRolesSplit = rolesSplit.Where(r => !string.IsNullOrWhiteSpace(r)).Select(r => r.Trim());
policyBuilder.RequireRole(trimmedRolesSplit);
useDefaultPolicy = false;
}
var authTypesSplit = authorizeDatum.AuthenticationSchemes?.Split(',');
if (authTypesSplit != null && authTypesSplit.Any())
{
foreach (var authType in authTypesSplit)
{
if (!string.IsNullOrWhiteSpace(authType))
{
policyBuilder.AuthenticationSchemes.Add(authType.Trim());
}
}
}
if (useDefaultPolicy)
{
policyBuilder.Combine(await policyProvider.GetDefaultPolicyAsync());
}
}
}
var requiredPolicy = await policyProvider.GetRequiredPolicyAsync();
if (requiredPolicy != null)
{
if (policyBuilder == null)
{
policyBuilder = new AuthorizationPolicyBuilder();
}
policyBuilder.Combine(requiredPolicy);
}
return(policyBuilder?.Build());
}