Fixed Library: Added signing to AWS requests.

14 years ago · c931a6bedb
parent 0413dcaaa4
commit c931a6bedb
3 changed files with 142 additions and 120 deletions
--- a/ceo/pymazon.py
+++ b/ceo/pymazon.py
@ -3,132 +3,153 @@
 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"""
-	def __init__(self, messages):
-		self.__message = '\n'.join(messages)
+    """Holds information about an error that occured during a pymazon request"""
+    def __init__(self, messages):
+        self.__message = '\n'.join(messages)

-	def __get_message(self):
-		return self.__message
+    def __get_message(self):
+        return self.__message

-	def __str__(self):
-		return repr(self.__message)
+    def __str__(self):
+        return repr(self.__message)

-	message = property(fget=__get_message)
+    message = property(fget=__get_message)


 class PyMazonBook:
-	"""Stores information about a book retrieved via PyMazon."""
-	def __init__(self, title, authors, publisher, year, isbn10, isbn13, edition):
-		self.__title = title
-		self.__authors = authors
-		self.__publisher = publisher
-		self.__year = year 
-		self.__isbn10 = isbn10
-		self.__isbn13 = isbn13
-		self.__edition = edition
-
-	def __str__(self):
-		return 'Title:     ' + self.title + '\n' + \
-		       'Author(s): ' + ', '.join(self.authors) + '\n' \
-				 'Publisher: ' + self.publisher + '\n' + \
-				 'Year:      ' + self.year + '\n' + \
-				 'ISBN-10:   ' + self.isbn10 + '\n' + \
-				 'ISBN-13:   ' + self.isbn13 + '\n' + \
-				 'Edition:   ' + self.edition
-
-	def __get_title(self):
-		return self.__title
-
-	def __get_authors(self):
-		return self.__authors
-	
-	def __get_publisher(self):
-		return self.__publisher
-
-	def __get_year(self):
-		return self.__year
-
-	def __get_isbn10(self):
-		return self.__isbn10
-
-	def __get_isbn13(self):
-		return self.__isbn13
-
-	def __get_edition(self):
-		return self.__edition
-
-	title = property(fget=__get_title)
-	authors = property(fget=__get_authors)
-	publisher = property(fget=__get_publisher)
-	year = property(fget=__get_year)
-	isbn10 = property(fget=__get_isbn10)
-	isbn13 = property(fget=__get_isbn13)
-	edition = property(fget=__get_edition)
+    """Stores information about a book retrieved via PyMazon."""
+    def __init__(self, title, authors, publisher, year, isbn10, isbn13, edition):
+        self.__title = title
+        self.__authors = authors
+        self.__publisher = publisher
+        self.__year = year 
+        self.__isbn10 = isbn10
+        self.__isbn13 = isbn13
+        self.__edition = edition
+
+    def __str__(self):
+        return 'Title:     ' + self.title + '\n' + \
+               'Author(s): ' + ', '.join(self.authors) + '\n' \
+                 'Publisher: ' + self.publisher + '\n' + \
+                 'Year:      ' + self.year + '\n' + \
+                 'ISBN-10:   ' + self.isbn10 + '\n' + \
+                 'ISBN-13:   ' + self.isbn13 + '\n' + \
+                 'Edition:   ' + self.edition
+
+    def __get_title(self):
+        return self.__title
+
+    def __get_authors(self):
+        return self.__authors
+    
+    def __get_publisher(self):
+        return self.__publisher
+
+    def __get_year(self):
+        return self.__year
+
+    def __get_isbn10(self):
+        return self.__isbn10
+
+    def __get_isbn13(self):
+        return self.__isbn13
+
+    def __get_edition(self):
+        return self.__edition
+
+    title = property(fget=__get_title)
+    authors = property(fget=__get_authors)
+    publisher = property(fget=__get_publisher)
+    year = property(fget=__get_year)
+    isbn10 = property(fget=__get_isbn10)
+    isbn13 = property(fget=__get_isbn13)
+    edition = property(fget=__get_edition)


 class PyMazon:
-	"""A method of looking up book information on Amazon."""
-	def __init__(self, accesskey):
-		self.__key = accesskey
-		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
-
-	def __elements_text(self, element, name):
-		result = []
-		matching = element.getElementsByTagName(name)
-		for match in matching:
-			if len(match.childNodes) != 1:
-				continue
-			child = match.firstChild
-			if child.nodeType != Node.TEXT_NODE:
-				continue
-			result.append(child.nodeValue.strip())
-		return result
-
-	def __format_errors(self, errors):
-		error_list = []
-		for error in errors:
-			error_list.extend(self.__elements_text(error, 'Message'))
-		return error_list
-
-	def __extract_single(self, element, name):
-		matches = self.__elements_text(element, name)
-		if len(matches) == 0:
-			return ''
-		return matches[0]
-
-	def lookup(self, isbn):
-		file = urllib.urlretrieve(self.__form_request(isbn))[0]
-		xmldoc = minidom.parse(file)
-
-		cur_time = time.time()
-		while cur_time - self.__last_query_time < 1.0:
-			sleep(cur_time - self.__last_query_time)
-			cur_time = time.time()
-		self.__last_query_time = cur_time
-
-		errors = xmldoc.getElementsByTagName('Errors')
-		if len(errors) != 0:
-			raise PyMazonError, self.__format_errors(errors)
-
-		title = self.__extract_single(xmldoc, 'Title')
-		authors = self.__elements_text(xmldoc, 'Author')
-		publisher = self.__extract_single(xmldoc, 'Publisher')
-		year = self.__extract_single(xmldoc, 'PublicationDate')[0:4]
-		isbn10 = self.__extract_single(xmldoc, 'ISBN')
-		isbn13 = self.__extract_single(xmldoc, 'EAN')
-		edition = self.__extract_single(xmldoc, 'Edition')
-
-		return PyMazonBook(title, authors, publisher, year, isbn10, isbn13, edition)
+    """A method of looking up book information on Amazon."""
+    def __init__(self, accesskey, secretkey):
+        self.__key = accesskey
+        self.__secret = secretkey
+        self.__last_query_time = 0
+
+    def __form_request(self, 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 = []
+        matching = element.getElementsByTagName(name)
+        for match in matching:
+            if len(match.childNodes) != 1:
+                continue
+            child = match.firstChild
+            if child.nodeType != Node.TEXT_NODE:
+                continue
+            result.append(child.nodeValue.strip())
+        return result
+
+    def __format_errors(self, errors):
+        error_list = []
+        for error in errors:
+            error_list.extend(self.__elements_text(error, 'Message'))
+        return error_list
+
+    def __extract_single(self, element, name):
+        matches = self.__elements_text(element, name)
+        if len(matches) == 0:
+            return ''
+        return matches[0]
+
+    def lookup(self, isbn):
+        file = urllib.urlretrieve(self.__form_request(isbn))[0]
+        xmldoc = minidom.parse(file)
+
+        cur_time = time.time()
+        while cur_time - self.__last_query_time < 1.0:
+            sleep(cur_time - self.__last_query_time)
+            cur_time = time.time()
+        self.__last_query_time = cur_time
+
+        errors = xmldoc.getElementsByTagName('Errors')
+        if len(errors) != 0:
+            raise PyMazonError, self.__format_errors(errors)
+
+        title = self.__extract_single(xmldoc, 'Title')
+        authors = self.__elements_text(xmldoc, 'Author')
+        publisher = self.__extract_single(xmldoc, 'Publisher')
+        year = self.__extract_single(xmldoc, 'PublicationDate')[0:4]
+        isbn10 = self.__extract_single(xmldoc, 'ISBN')
+        isbn13 = self.__extract_single(xmldoc, 'EAN')
+        edition = self.__extract_single(xmldoc, 'Edition')
+        
+        return PyMazonBook(title, authors, publisher, year, isbn10, isbn13, edition)
--- a/ceo/urwid/library.py
+++ b/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)
--- a/etc/library.cf
+++ b/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"