Allows generating signed PUT urls.

README.md

Usage:

s3 = AWS::S3.new(...) 
s3.buckets['bucket-name'].objects['object-name.jpg'].url_for(:write, content_type: 'image/jpeg')

Generates a signed request allowing a PUT /bucket-name/object-name.jpg with an image file, so that an HTTP PUT can be used instead of a presigned_post request with HTTP POST and a bunch of hidden fields.

aws_monkey_patch.rb

require 'aws'

# Monkey patched
module AWS
  class S3
    class S3Object
      # new version of signature method that sets content type
      def hacked_signature(method, expires, request, content_type = "")
        parts = []
        parts << method
        parts << ""
        parts << content_type
        parts << expires
        if config.credential_provider.session_token
          parts << "x-amz-security-token:"
          parts << "#{config.credential_provider.session_token}"
        end
        parts << request.canonicalized_resource

        string_to_sign = parts.join("\n")

        secret = config.credential_provider.secret_access_key
        Core::Signer.sign(secret, string_to_sign, 'sha1')
      end

      def url_for(method, options = {})
        req = request_for_signing(options)

        method = http_method(method)
        content_type = options.delete(:content_type) || ""
        expires = expiration_timestamp(options[:expires])
        req.add_param("AWSAccessKeyId",
                      config.credential_provider.access_key_id)
        req.add_param("versionId", options[:version_id]) if options[:version_id]
        req.add_param("Signature", hacked_signature(method, expires, req, content_type))
        req.add_param("Expires", expires)
        req.add_param("x-amz-security-token",
                      config.credential_provider.session_token) if
          config.credential_provider.session_token

        build_uri(options[:secure] != false, req)
      end
    end

  end
end