NAME

AWS::Signature4 - Create a version4 signature for Amazon Web Services

SYNOPSIS

 use AWS::Signature4;
 use HTTP::Request::Common;
 use LWP;

 my $signer = AWS::Signature4->new(-access_key => 'AKIDEXAMPLE',
                                   -secret_key => 'wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY');
 my $ua     = LWP::UserAgent->new();

 # Example POST request
 my $request = POST('https://iam.amazonaws.com',
		    [Action=>'ListUsers',
		     Version=>'2010-05-08']);
 $signer->sign($request);
 my $response = $ua->request($request);

 # Example GET request
 my $uri     = URI->new('https://iam.amazonaws.com');
 $uri->query_form(Action=>'ListUsers',
		  Version=>'2010-05-08');

 my $url = $signer->signed_url($uri); # This gives a signed URL that can be fetched by a browser
 my $response = $ua->get($url);

DESCRIPTION

This module implement's Amazon Web Service's Signature version 4 (http://docs.aws.amazon.com/general/latest/gr/signature-version-4.html).

METHODS

$signer = AWS::Signature4->new(-access_key => $account_id,-secret_key => $private_key);

Create a signing object using your AWS account ID and secret key. You may also use the temporary security tokens received from Amazon's STS service, either by passing the access and secret keys derived from the token, or by passing a VM::EC2::Security::Token produced by the VM::EC2 module.

Arguments:

Argument name       Argument Value
-------------       --------------
-access_key         An AWS acccess key (account ID)

-secret_key         An AWS secret key

-security_token     A VM::EC2::Security::Token object

If a security token is provided, it overrides any values given for -access_key or -secret_key.

If the environment variables EC2_ACCESS_KEY and/or EC2_SECRET_KEY are set, their contents are used as defaults for -acccess_key and -secret_key.

$signer->sign($request [,$region] [,$payload_sha256_hex])

Given an HTTP::Request object, add the headers required by AWS and then sign it with a version 4 signature by adding an "Authorization" header.

The request must include a URL from which the AWS endpoint and service can be derived, such as "ec2.us-east-1.amazonaws.com." In some cases (e.g. S3 bucket operations) the endpoint does not indicate the region. In this case, the region can be forced by passing a defined value for $region. The current date and time will be added to the request using an "X-Amz-Date header." To force the date and time to a fixed value, include the "Date" header in the request.

The request content, or "payload" is retrieved from the HTTP::Request object by calling its content() method.. Under some circumstances the payload is not included directly in the request, but is in an external file that will be uploaded as the request is executed. In this case, you must pass a second argument containing the results of running sha256_hex() (from the Digest::SHA module) on the content.

The method returns a true value if successful. On errors, it will throw an exception.

$url = $signer->signed_url($request)

This method will generate a signed GET URL for the request. The URL will include everything needed to perform the request.

my $url $signer->signed_url($request_or_uri [,$expires])

Pass an HTTP::Request, a URI object, or just a plain URL string containing the proper endpoint and parameters needed for an AWS REST API Call. This method will return an appropriately signed request as a URI object, which can be shared with non-AWS users for the purpose of, e.g., accessing an object in a private S3 bucket.

Pass an optional $expires argument to indicate that the URL will only be valid for a finite period of time. The value of the argument is in seconds.

$signing_key = AWS::Signature4->signing_key($secret_access_key,$service_name,$region,$date)

Return just the signing key in the event you wish to roll your own signature.

SEE ALSO

VM::EC2

AUTHOR

Lincoln Stein <lincoln.stein@gmail.com>.

Copyright (c) 2014 Ontario Institute for Cancer Research

This package and its accompanying libraries is free software; you can redistribute it and/or modify it under the terms of the GPL (either version 1, or at your option, any later version) or the Artistic License 2.0. Refer to LICENSE for the full license text. In addition, please see DISCLAIMER.txt for disclaimers of warranty.