Dart

How to Generate an Azure Storage Account Shared Access Signature (SAS)

See more Azure Cloud Storage Examples

Shows how to generate a Shared Access Signature (SAS) for an Azure Storage Account.

Note: This example requires Chilkat v9.5.0.65 or greater.

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Note: Requires Chilkat v9.5.0.65 or greater.

  // This requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  // --------------------------------------------------------------------------
  // Create a Shared Access Signature (SAS) token for an Azure Storage Account.
  // --------------------------------------------------------------------------

  // See https://docs.microsoft.com/en-us/rest/api/storageservices/fileservices/constructing-an-account-sas 
  // for details regarding the Azure Storage Account SAS fields.

  final authSas = CkAuthAzureSAS();
  authSas.accessKey = 'AZURE_ACCESS_KEY';

  // Specify the format of the string to sign.
  // Each comma character in the following string represents a LF ("\n") character.
  // The names specified in the StringToSign are replaced with the values specified
  // in the subsequent calls to SetTokenParam and SetNonTokenParam,.

  // Note: The trailing comma in the StringToSign is intentional and important. This indicates that the 
  // string to sign will end with a "\n".

  // Also note: The names in the StringToSign are case sensitive.  The names
  // specified in the 1st argument in the calls to SetNonTokenParam and SetTokenParam should
  // match a name listed in StringToSign. 
  authSas.stringToSign = 'accountname,signedpermissions,signedservice,signedresourcetype,signedstart,signedexpiry,signedIP,signedProtocol,signedversion,';

  //  The account name is "chilkat".  Use your own account name instead of "chilkat".
  //  Also use your own container name instead of "mycontainer".
  authSas.setNonTokenParam('accountname', 'chilkat');

  authSas.setTokenParam('signedpermissions', 'sp', 'rwdlacup');
  authSas.setTokenParam('signedservice', 'ss', 'bfqt');
  authSas.setTokenParam('signedresourcetype', 'srt', 'sco');

  final dt = CkDateTime();
  dt.setFromCurrentSystemTime();
  authSas.setTokenParam('signedstart', 'st', dt.getAsIso8601('YYYY-MM-DDThh:mmTZD', false));

  // This SAS token will be valid for 30 days.
  dt.addDays(30);
  authSas.setTokenParam('signedexpiry', 'se', dt.getAsIso8601('YYYY-MM-DDThh:mmTZD', false));

  authSas.setTokenParam('signedProtocol', 'spr', 'https');

  //  Specifiy values and query param names for each field.
  //  If a field is not specified, then an empty string will be used for its value.
  authSas.setTokenParam('signedversion', 'sv', '2015-04-05');

  // Note that we did not call SetTokenParam for "signedIP".  For any omitted fields
  // the value will default to the empty string.

  // Generate the SAS token.
  final String sasToken;
  try {
    sasToken = authSas.generateToken();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('SAS token: $sasToken');

  // Save the SAS token to a file.
  // We can then use this pre-generated token for future Azure Storage Account operations.
  final fac = CkFileAccess();
  fac.writeEntireTextFile('qa_data/tokens/azureStorageAccountSas.txt', sasToken, 'utf-8', false);
}