From e5d0cddf2c46d59d36f5c6e2234a0a46fa03c21b Mon Sep 17 00:00:00 2001
From: Frederick Cheung <frederick.cheung@gmail.com>
Date: Mon, 3 Nov 2014 15:50:41 +0000
Subject: [PATCH] [AWS|SNS] Use Signature v4

---
 lib/fog/aws/sns.rb | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/lib/fog/aws/sns.rb b/lib/fog/aws/sns.rb
index 76cf6df26..70af5a79e 100644
--- a/lib/fog/aws/sns.rb
+++ b/lib/fog/aws/sns.rb
@@ -49,12 +49,12 @@ module Fog
         # * SNS object with connection to AWS.
         def initialize(options={})
           @use_iam_profile = options[:use_iam_profile]
-          setup_credentials(options)
           @connection_options     = options[:connection_options] || {}
           @instrumentor       = options[:instrumentor]
           @instrumentor_name  = options[:instrumentor_name] || 'fog.aws.sns'
 
           options[:region] ||= 'us-east-1'
+          @region = options[:region]
           @host = options[:host] || "sns.#{options[:region]}.amazonaws.com"
 
           @path       = options[:path]        || '/'
@@ -62,6 +62,8 @@ module Fog
           @port       = options[:port]        || 443
           @scheme     = options[:scheme]      || 'https'
           @connection = Fog::XML::Connection.new("#{@scheme}://#{@host}:#{@port}#{@path}", @persistent, @connection_options)
+
+          setup_credentials(options)
         end
 
         def reload
@@ -76,7 +78,7 @@ module Fog
           @aws_session_token     = options[:aws_session_token]
           @aws_credentials_expire_at = options[:aws_credentials_expire_at]
 
-          @hmac       = Fog::HMAC.new('sha256', @aws_secret_access_key)
+          @signer = Fog::AWS::SignatureV4.new( @aws_access_key_id, @aws_secret_access_key, @region, 'sns')
         end
 
         def request(params)
@@ -85,12 +87,13 @@ module Fog
           idempotent  = params.delete(:idempotent)
           parser      = params.delete(:parser)
 
-          body = AWS.signed_params(
+          body, headers = AWS.signed_params_v4(
             params,
+            { 'Content-Type' => 'application/x-www-form-urlencoded' },
             {
-              :aws_access_key_id  => @aws_access_key_id,
+              :method             => 'POST',
               :aws_session_token  => @aws_session_token,
-              :hmac               => @hmac,
+              :signer             => @signer,
               :host               => @host,
               :path               => @path,
               :port               => @port
@@ -99,19 +102,19 @@ module Fog
 
           if @instrumentor
             @instrumentor.instrument("#{@instrumentor_name}.request", params) do
-              _request(body, idempotent, parser)
+              _request(body, headers, idempotent, parser)
             end
           else
-            _request(body, idempotent, parser)
+            _request(body, headers, idempotent, parser)
           end
         end
 
-        def _request(body, idempotent, parser)
+        def _request(body, headers, idempotent, parser)
           @connection.request({
             :body       => body,
             :expects    => 200,
             :idempotent => idempotent,
-            :headers    => { 'Content-Type' => 'application/x-www-form-urlencoded' },
+            :headers    => headers,
             :method     => 'POST',
             :parser     => parser
           })