A simple tool that will help you enable MFA Delete feature on your S3 bucket

mfa-delete.rb

#!/usr/bin/env ruby
require 'aws'

if ARGV.length < 5
  print <<-EOF
Usage: mfa-delete.rb <bucket_name> <aws_id> <aws_secret> <mfa_serial> <mfa_token> <s3_endpoint>
<s3_endpoint> is optional
  EOF
  exit
end

bucket_name = ARGV[0]
aws_id      = ARGV[1]
aws_key     = ARGV[2]
mfa_serial  = ARGV[3]
mfa_token   = ARGV[4]
s3_endpoint = ARGV[5] || "s3.amazonaws.com"

s3 = AWS::S3.new({
  :s3_endpoint => s3_endpoint,
  :access_key_id => aws_id,
  :secret_access_key => aws_key
})

bucket = s3.buckets[bucket_name]
bucket.enable_versioning :mfa_delete=>'Enabled', :mfa=>"#{mfa_serial} #{mfa_token}"