Rename the S3 provider to just S3

lib/remote_storage/s3.rb

@@ -0,0 +1,110 @@
+require "remote_storage/rest_provider"
+require "digest"
+require "base64"
+require "openssl"
+require "webrick/httputils"
+
+module RemoteStorage
+  class S3
+    include RestProvider
+
+    private
+
+    # S3 already wraps the ETag around quotes
+    def format_etag(etag)
+      etag
+    end
+
+    def do_put_request(url, data, content_type)
+      deal_with_unauthorized_requests do
+        md5 = Digest::MD5.base64digest(data)
+        authorization_headers = authorization_headers_for("PUT", url, md5, content_type)
+        RestClient.put(url, data, authorization_headers.merge({ "Content-Type" => content_type, "Content-Md5" => md5}))
+      end
+    end
+
+    def do_put_request_and_return_etag_and_last_modified(url, data, content_type)
+      res = do_put_request(url, data, content_type)
+      # S3 does not return a Last-Modified response header on PUTs
+      head_res = do_head_request(url)
+
+      return [res.headers[:etag].delete('"'), timestamp_for(head_res.headers[:last_modified])]
+    end
+
+    def do_get_request(url, &block)
+      deal_with_unauthorized_requests do
+        authorization_headers = authorization_headers_for("GET", url)
+        RestClient.get(url, authorization_headers, &block)
+      end
+    end
+
+    def do_head_request(url, &block)
+      deal_with_unauthorized_requests do
+        authorization_headers = authorization_headers_for("HEAD", url)
+        RestClient.head(url, authorization_headers, &block)
+      end
+    end
+
+    def do_delete_request(url)
+      deal_with_unauthorized_requests do
+        authorization_headers = authorization_headers_for("DELETE", url)
+        RestClient.delete(url, authorization_headers)
+      end
+    end
+
+    def try_to_delete(url)
+      found = true
+
+      begin
+        do_head_request(url)
+      rescue RestClient::ResourceNotFound
+        found = false
+      end
+
+      do_delete_request(url) if found
+
+      return found
+    end
+
+    # This is using the S3 authorizations, not the newer AW V4 Signatures
+    # (https://s3.amazonaws.com/doc/s3-developer-guide/RESTAuthentication.html)
+    def authorization_headers_for(http_verb, url, md5 = nil, content_type = nil)
+      url = File.join("/", url.gsub(base_url, ""))
+      date = Time.now.httpdate
+      signed_data = generate_s3_signature(http_verb, md5, content_type, date, url)
+      { "Authorization" => "AWS #{credentials[:access_key_id]}:#{signed_data}",
+        "Date" => date}
+    end
+
+    def credentials
+      @credentials ||= { access_key_id: settings.s3["access_key_id"], secret_key_id: settings.s3["secret_key_id"] }
+    end
+
+    def digest(secret, string_to_sign)
+      Base64.encode64(hmac(secret, string_to_sign)).strip
+    end
+
+    def hmac(key, value)
+      OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha1'), key, value)
+    end
+
+    def uri_escape(s)
+      WEBrick::HTTPUtils.escape(s).gsub('%5B', '[').gsub('%5D', ']')
+    end
+
+    def generate_s3_signature(http_verb, md5, content_type, date, url)
+      string_to_sign = [http_verb, md5, content_type, date, url].join "\n"
+      signature = digest(credentials[:secret_key_id], string_to_sign)
+      uri_escape(signature)
+    end
+
+    def base_url
+      @base_url ||= settings.s3["endpoint"]
+    end
+
+    def container_url_for(user)
+      "#{base_url}#{settings.s3["bucket"]}/#{user}"
+    end
+  end
+
+end