Fixed Library: Added signing to AWS requests.

ceo/pymazon.py

@@ -3,6 +3,10 @@
 from xml.dom import minidom, Node
 import urllib
 import time
+import datetime
+import hashlib
+import base64
+import hmac
 
 class PyMazonError(Exception):
     """Holds information about an error that occured during a pymazon request"""
@@ -70,20 +74,37 @@ class PyMazonBook:
 
 class PyMazon:
     """A method of looking up book information on Amazon."""
-	def __init__(self, accesskey):
+    def __init__(self, accesskey, secretkey):
         self.__key = accesskey
+        self.__secret = secretkey
         self.__last_query_time = 0
 
     def __form_request(self, isbn):
-		return 'http://webservices.amazon.com/onca/xml?' + \
-		       'Service=AWSECommerceService' + \
-				 '&Version=2008-08-19' + \
-		       '&AWSAccessKeyId=' + self.__key + \
-				 '&Operation=ItemLookup' + \
-				 '&ResponseGroup=ItemAttributes' + \
-				 '&IdType=ISBN' + \
-				 '&SearchIndex=Books' + \
-				 '&ItemId=' + isbn
+        content = {}
+        dstamp = datetime.datetime.utcfromtimestamp(time.time())
+        content['Timestamp'] = dstamp.strftime('%Y-%m-%dT%H:%M:%S.000Z')
+        content['Service'] = 'AWSECommerceService'
+        content['Version'] = '2008-08-19'
+        content['Operation'] = 'ItemLookup'
+        content['ResponseGroup'] = 'ItemAttributes'
+        content['IdType'] = 'ISBN'
+        content['SearchIndex'] = 'Books'
+        content['ItemId'] = isbn
+        content['AWSAccessKeyId'] = self.__key
+
+        URI_String = []
+
+        for key, value in sorted(content.items()):
+            URI_String.append('%s=%s' % (key, urllib.quote(value)))
+
+        req = '&'.join(URI_String)
+        to_sign_req = 'GET\necs.amazonaws.com\n/onca/xml\n' + req
+
+        h = hmac.new(self.__secret, to_sign_req, hashlib.sha256)
+        sig = base64.b64encode(h.digest())
+        req += '&Signature=%s' % urllib.quote(sig)
+
+        return 'http://ecs.amazonaws.com/onca/xml?' + req
 
     def __elements_text(self, element, name):
         result = []

ceo/urwid/library.py

@@ -21,7 +21,7 @@ def configure():
     """
     Load configuration
     """
-    cfg_fields = [ "aws_account_key" ]
+    cfg_fields = [ "aws_account_key", "aws_secret_key" ]
     temp_cfg = conf.read(CONFIG_FILE)
     conf.check_string_fields(CONFIG_FILE, cfg_fields, temp_cfg)
     cfg.update(temp_cfg)
@@ -127,7 +127,7 @@ class BookAddPage(WizardPanel):
         isbn = self.isbn.get_edit_text()
 
         try:
-            pymazon = PyMazon(cfg["aws_account_key"])
+            pymazon = PyMazon(cfg["aws_account_key"], cfg["aws_secret_key"])
             book = pymazon.lookup(isbn)
 
             currents = lib.Book.select(lib.Book.q.isbn==isbn)

etc/library.cf

@@ -2,3 +2,4 @@
 
 library_connect_string = "postgres://librarian:PWPWPWPWPWPWPWPWPWPW@127.0.0.1/library"
 aws_account_key = "KEYKEYKEYKEYKEYKEYKY"
+aws_secret_key = "KEYKEYKEYKEYKEYKEYKY"