Dart

Create an Azure Service SAS

See more Azure Cloud Storage Examples

Shows how to generate an Azure Service SAS. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // 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 Service (Blob, Queue, Table, or File)
  // -----------------------------------------------------------------------------------------------

  // See https://docs.microsoft.com/en-us/rest/api/storageservices/create-service-sas
  // for details.

  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. 

  // Version 2018-11-09 and later
  // 
  // Version 2018-11-09 adds support for the signed resource and signed blob snapshot time fields. 
  // These must be included in the string-to-sign. To construct the string-to-sign for Blob service resources, use the following format:
  // 
  // StringToSign = signedpermissions + "\n" +  
  //                signedstart + "\n" +  
  //                signedexpiry + "\n" +  
  //                canonicalizedresource + "\n" +  
  //                signedidentifier + "\n" +  
  //                signedIP + "\n" +  
  //                signedProtocol + "\n" +  
  //                signedversion + "\n" +  
  //                signedResource + "\n"
  //                signedSnapshotTime + "\n" +
  //                rscc + "\n" +  
  //                rscd + "\n" +  
  //                rsce + "\n" +  
  //                rscl + "\n" +  
  //                rsct  
  // 

  authSas.stringToSign = 'signedpermissions,signedstart,signedexpiry,canonicalizedresource,signedidentifier,signedIP,signedProtocol,signedversion,signedResource,signedSnapshotTime,rscc,rscd,rsce,rscl,rsct';

  authSas.setTokenParam('signedpermissions', 'sp', 'rw');

  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));

  // The canonicalizedresouce portion of the string is a canonical path to the signed resource. It must include the service name (blob, table, queue or file) for version
  // 2021-08-06 or later, the storage account name, and the resource name, and must be URL-decoded. Names of blobs must include the blob�s container. Table names must be
  // lower-case. The following examples show how to construct the canonicalizedresource portion of the string, depending on the type of resource.
  // For example:
  // URL = https://chilkat.blob.core.windows.net/mycontainer/starfish.jpg
  // canonicalizedresource = "/blob/chilkat/mycontainer/starfish.jpg"  
  // IMPORTANT: See https://docs.microsoft.com/en-us/rest/api/storageservices/create-service-sas for all details..
  authSas.setNonTokenParam('canonicalizedresource', '/blob/chilkat/mycontainer/starfish.jpg');

  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', '2018-11-09');

  // Indicate that we are creating a service SAS that is limited to the blob resource.
  // (Specify b if the shared resource is a blob. This grants access to the content and metadata of the blob.
  //  Specify c if the shared resource is a container. This grants access to the content and metadata of any blob in the container, and to the list of blobs in the container. )
  authSas.setTokenParam('signedResource', 'sr', 'b');

  // Note that we did not call SetTokenParam for "signedIP", "signedSnapshotTime", "rscc", and others.  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 Service 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/azureStorageServiceSas.txt', sasToken, 'utf-8', false);
}