public static string GetFileSasUri(string filePath, DateTime expiration, ShareFileSasPermissions permissions)
{
string shareName = MyWebUtils.Application.ToLower();
// Get the account details from app settings
string accountName = Properties.Settings.Default.StorageAccountName;
string accountKey = Properties.Settings.Default.StorageAccountKey;
ShareSasBuilder fileSAS = new ShareSasBuilder()
{
ShareName = shareName,
FilePath = filePath,
// Specify an Azure file resource
Resource = "f",
// Expires in 24 hours
ExpiresOn = expiration
};
// Set the permissions for the SAS
fileSAS.SetPermissions(permissions);
// Create a SharedKeyCredential that we can use to sign the SAS token
StorageSharedKeyCredential credential = new StorageSharedKeyCredential(accountName, accountKey);
// Build a SAS URI
UriBuilder fileSasUri = new UriBuilder($"https://{accountName}.file.core.windows.net/{fileSAS.ShareName}/{fileSAS.FilePath}");
fileSasUri.Query = fileSAS.ToSasQueryParameters(credential).ToString();
// Return the URI
return(fileSasUri.Uri.ToString());
}
/// <summary>
/// Create a permissions string to provide
/// <see cref="ShareSasBuilder.Permissions"/>.
/// </summary>
/// <returns>A permissions string.</returns>
internal static string ToPermissionsString(this ShareFileSasPermissions permissions)
{
var sb = new StringBuilder();
if ((permissions & ShareFileSasPermissions.Read) == ShareFileSasPermissions.Read)
{
sb.Append(Constants.Sas.Permissions.Read);
}
if ((permissions & ShareFileSasPermissions.Create) == ShareFileSasPermissions.Create)
{
sb.Append(Constants.Sas.Permissions.Create);
}
if ((permissions & ShareFileSasPermissions.Write) == ShareFileSasPermissions.Write)
{
sb.Append(Constants.Sas.Permissions.Write);
}
if ((permissions & ShareFileSasPermissions.Delete) == ShareFileSasPermissions.Delete)
{
sb.Append(Constants.Sas.Permissions.Delete);
}
return(sb.ToString());
}
/// <summary>
/// Sets the permissions for a file SAS.
/// </summary>
/// <param name="permissions">
/// <see cref="ShareFileSasPermissions"/> containing the allowed permissions.
/// </param>
public void SetPermissions(ShareFileSasPermissions permissions)
{
Permissions = permissions.ToPermissionsString();
}
/// <summary>
/// Initializes a new instance of the <see cref="ShareSasBuilder"/>
/// class to create a Blob Service Sas.
/// </summary>
/// <param name="permissions">
/// The time at which the shared access signature becomes invalid.
/// This field must be omitted if it has been specified in an
/// associated stored access policy.
/// </param>
/// <param name="expiresOn">
/// The time at which the shared access signature becomes invalid.
/// This field must be omitted if it has been specified in an
/// associated stored access policy.
/// </param>
public ShareSasBuilder(ShareFileSasPermissions permissions, DateTimeOffset expiresOn)
{
ExpiresOn = expiresOn;
SetPermissions(permissions);
}
public async Task <Uri> CreateShareFileSasUriAsync(string shareName, string filePath, ShareFileSasPermissions permissions, DateTimeOffset expiresOn)
{
if (string.IsNullOrWhiteSpace(shareName))
{
throw new ArgumentException($"'{nameof(shareName)}' cannot be null or whitespace.", nameof(shareName));
}
if (string.IsNullOrWhiteSpace(filePath))
{
throw new ArgumentException($"'{nameof(filePath)}' cannot be null or whitespace.", nameof(filePath));
}
var client = await CreateShareFileClientAsync(shareName, filePath, useSharedKey : true)
.ConfigureAwait(false);
return(client.GenerateSasUri(permissions, expiresOn));
}
