Fixed Library: Added signing to AWS requests.

This commit is contained in:
Michael Ellis 2009-09-08 17:04:44 -04:00
parent 0413dcaaa4
commit c931a6bedb
3 changed files with 125 additions and 103 deletions

View File

@ -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
"""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 __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_title(self):
return self.__title
def __get_authors(self):
return self.__authors
def __get_publisher(self):
return self.__publisher
def __get_authors(self):
return self.__authors
def __get_publisher(self):
return self.__publisher
def __get_year(self):
return self.__year
def __get_year(self):
return self.__year
def __get_isbn10(self):
return self.__isbn10
def __get_isbn10(self):
return self.__isbn10
def __get_isbn13(self):
return self.__isbn13
def __get_isbn13(self):
return self.__isbn13
def __get_edition(self):
return self.__edition
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)
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
"""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):
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 __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
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
URI_String = []
def __format_errors(self, errors):
error_list = []
for error in errors:
error_list.extend(self.__elements_text(error, 'Message'))
return error_list
for key, value in sorted(content.items()):
URI_String.append('%s=%s' % (key, urllib.quote(value)))
def __extract_single(self, element, name):
matches = self.__elements_text(element, name)
if len(matches) == 0:
return ''
return matches[0]
req = '&'.join(URI_String)
to_sign_req = 'GET\necs.amazonaws.com\n/onca/xml\n' + req
def lookup(self, isbn):
file = urllib.urlretrieve(self.__form_request(isbn))[0]
xmldoc = minidom.parse(file)
h = hmac.new(self.__secret, to_sign_req, hashlib.sha256)
sig = base64.b64encode(h.digest())
req += '&Signature=%s' % urllib.quote(sig)
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
return 'http://ecs.amazonaws.com/onca/xml?' + req
errors = xmldoc.getElementsByTagName('Errors')
if len(errors) != 0:
raise PyMazonError, self.__format_errors(errors)
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
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')
def __format_errors(self, errors):
error_list = []
for error in errors:
error_list.extend(self.__elements_text(error, 'Message'))
return error_list
return PyMazonBook(title, authors, publisher, year, isbn10, isbn13, edition)
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)

View File

@ -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)

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