awscr-signer

Crystal interface for AWS Signing.

Supports signing Crytal HTTP::Request objects and generating presigned post form for browser or programatic uploading. See Browser-Based Uploads Using POST and Authenticating Requests (AWS Signature Version 4) for additional details.

Installation

Add this to your application's shard.yml:

dependencies:
  awscr-signer:
    github: taylorfinnell/awscr-signer

Usage

Creating a Credentials object.

  Awscr::Signer::Credentials.new("SECRET_KEY", "SECRET")

Creating a Scope object.

  # where s3 is any amazon service
  # where us-east-1 is any region
  Awscr::Signer::Scope.new("us-east-1", "s3")

Signing an HTTP::Request.

signer = Awscr::Signer::V4.new(request, scope, credentials)
signer.sign

NOTE: It may be required for you to set the Host header to the AWS service before signing.

Creating a Presigned::Form.

form = Awscr::Signer::Presigned::Form.build("us-east-1", credentials) do |form|
  form.expiration(Time.epoch(Time.now.epoch + 1000))
  form.condition("bucket", BUCKET)
  form.condition("acl", "public-read")
  form.condition("key", SecureRandom.uuid)
  form.condition("Content-Type", "text/plain")
  form.condition("success_action_status", "201")
end

Converting the form to raw HTML (for browser uploads, etc).

puts form.to_html

Submitting the form via HTTP::Client.

form.submit(IO::Memory.new("Hello, S3!"))

Examples

Known Limitations

The following items are known issues.

• The request URI can not contain repeating slashes
• The request headers can not have new line separted values
• The request path can not contain spaces