hMtBSzfg

1require 'base64'
2require 'openssl'
3require 'cgi'
4
5module HmacRequestSigning
6  def inject_signature_header(headers, signature)
7    headers['X-Hmac-Sha256'] = signature
8    headers
9  end
10
11  def request_signature(request)
12    request.headers['X_HMAC_SHA256']
13  end
14
15  def hmac_sha256(key, message)
16    digest = OpenSSL::HMAC.digest('sha256', key, message)
17    # chomp -- the base64 encoded version will have a newline at the end
18    Base64.encode64(digest).chomp
19  end
20
21  def sign_params(verb, host, path, secret_key, params)
22    hmac_sha256(secret_key, serialized_params(verb, host, path, params))
23  end
24
25  def serialized_params(verb, host, path, params)
26    [ verb.to_s.upcase,
27      host,
28      path,
29      canonicalize_params(params) ].join("\n")
30  end
31
32  def canonicalize_params(params)
33    # Make sure we have string keys, otherwise the sort does not work
34    params.keys.sort.map do |key|
35      [CGI.escape(key.to_s), CGI.escape(params[key].to_s)].join('=')
36    end.join('&')
37  end
38end