text: /*
    * Copyright 2010-2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
    * 
    * Licensed under the Apache License, Version 2.0 (the "License").
    * You may not use this file except in compliance with the License.
    * A copy of the License is located at
    * 
    *  http://aws.amazon.com/apache2.0
    * 
    * or in the "license" file accompanying this file. This file is distributed
    * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
    * express or implied. See the License for the specific language governing
    * permissions and limitations under the License.
    */
  
  #include <aws/core/auth/AWSCredentialsProviderChain.h>
  #include <aws/core/platform/Environment.h>
  #include <aws/core/utils/memory/AWSMemory.h>
  #include <aws/core/utils/StringUtils.h>
  #include <aws/core/utils/logging/LogMacros.h>
  
  using namespace Aws::Auth;
  
  static const char AWS_ECS_CONTAINER_CREDENTIALS_RELATIVE_URI[] = "AWS_CONTAINER_CREDENTIALS_RELATIVE_URI";
  static const char AWS_ECS_CONTAINER_CREDENTIALS_FULL_URI[] = "AWS_CONTAINER_CREDENTIALS_FULL_URI";
  static const char AWS_ECS_CONTAINER_AUTHORIZATION_TOKEN[] = "AWS_CONTAINER_AUTHORIZATION_TOKEN";
  static const char AWS_EC2_METADATA_DISABLED[] = "AWS_EC2_METADATA_DISABLED";
  static const char DefaultCredentialsProviderChainTag[] = "DefaultAWSCredentialsProviderChain";
  
  AWSCredentials AWSCredentialsProviderChain::GetAWSCredentials()
  {
      for (auto credentialsProvider : m_providerChain)
      {
          AWSCredentials credentials = credentialsProvider->GetAWSCredentials();
          if (!credentials.GetAWSAccessKeyId().empty() && !credentials.GetAWSSecretKey().empty())
          {
              return credentials;
          }
      }
  
      return AWSCredentials("", "");
  }
  
  DefaultAWSCredentialsProviderChain::DefaultAWSCredentialsProviderChain() : AWSCredentialsProviderChain()
  {
      AddProvider(Aws::MakeShared<EnvironmentAWSCredentialsProvider>(DefaultCredentialsProviderChainTag));
      AddProvider(Aws::MakeShared<ProfileConfigFileAWSCredentialsProvider>(DefaultCredentialsProviderChainTag));
   
      //ECS TaskRole Credentials only available when ENVIRONMENT VARIABLE is set
      const auto relativeUri = Aws::Environment::GetEnv(AWS_ECS_CONTAINER_CREDENTIALS_RELATIVE_URI);
      AWS_LOGSTREAM_DEBUG(DefaultCredentialsProviderChainTag, "The environment variable value " << AWS_ECS_CONTAINER_CREDENTIALS_RELATIVE_URI
              << " is " << relativeUri);
  
      const auto absoluteUri = Aws::Environment::GetEnv(AWS_ECS_CONTAINER_CREDENTIALS_FULL_URI);
      AWS_LOGSTREAM_DEBUG(DefaultCredentialsProviderChainTag, "The environment variable value " << AWS_ECS_CONTAINER_CREDENTIALS_FULL_URI
              << " is " << absoluteUri);
  
      const auto ec2MetadataDisabled = Aws::Environment::GetEnv(AWS_EC2_METADATA_DISABLED);
      AWS_LOGSTREAM_DEBUG(DefaultCredentialsProviderChainTag, "The environment variable value " << AWS_EC2_METADATA_DISABLED
              << " is " << ec2MetadataDisabled);
  
      if (!relativeUri.empty())
      {
          AddProvider(Aws::MakeShared<TaskRoleCredentialsProvider>(DefaultCredentialsProviderChainTag, relativeUri.c_str()));
          AWS_LOGSTREAM_INFO(DefaultCredentialsProviderChainTag, "Added ECS metadata service credentials provider with relative path: ["
                  << relativeUri << "] to the provider chain.");
      }
      else if (!absoluteUri.empty())
      {
          const auto token = Aws::Environment::GetEnv(AWS_ECS_CONTAINER_AUTHORIZATION_TOKEN);
          AddProvider(Aws::MakeShared<TaskRoleCredentialsProvider>(DefaultCredentialsProviderChainTag,
                      absoluteUri.c_str(), token.c_str()));
  
          //DO NOT log the value of the authorization token for security purposes.
          AWS_LOGSTREAM_INFO(DefaultCredentialsProviderChainTag, "Added ECS credentials provider with URI: ["
                  << absoluteUri << "] to the provider chain with a" << (token.empty() ? "n empty " : " non-empty ")
                  << "authorization token.");
      }
      else if (Aws::Utils::StringUtils::ToLower(ec2MetadataDisabled.c_str()) != "true")
      {
          AddProvider(Aws::MakeShared<InstanceProfileCredentialsProvider>(DefaultCredentialsProviderChainTag));
          AWS_LOGSTREAM_INFO(DefaultCredentialsProviderChainTag, "Added EC2 metadata service credentials provider to the provider chain.");
      }
  }
  