using botocore for s3 request signing: proof of concept

scrapy/core/downloader/handlers/s3.py

+import six
 from six.moves.urllib.parse import unquote
 
 from scrapy.exceptions import NotConfigured
 from scrapy.utils.httpobj import urlparse_cached
+from scrapy.utils.python import to_unicode
 from .http import HTTPDownloadHandler
 
 
@@ -37,10 +39,6 @@ class S3DownloadHandler(object):
     def __init__(self, settings, aws_access_key_id=None, aws_secret_access_key=None, \
             httpdownloadhandler=HTTPDownloadHandler, **kw):
 
-        _S3Connection = get_s3_connection()
-        if _S3Connection is None:
-            raise NotConfigured("missing boto library")
-
         if not aws_access_key_id:
             aws_access_key_id = settings['AWS_ACCESS_KEY_ID']
         if not aws_secret_access_key:
@@ -53,10 +51,27 @@ class S3DownloadHandler(object):
         if anon is None and not aws_access_key_id and not aws_secret_access_key:
             kw['anon'] = True
 
+        self._signer = None
         try:
-            self.conn = _S3Connection(aws_access_key_id, aws_secret_access_key, **kw)
-        except Exception as ex:
-            raise NotConfigured(str(ex))
+            import botocore.auth
+            import botocore.credentials
+        except ImportError:
+            if six.PY3:
+                raise NotConfigured("missing botocore library")
+            _S3Connection = get_s3_connection()
+            if _S3Connection is None:
+                raise NotConfigured("missing botocore or boto library")
+            try:
+                self.conn = _S3Connection(
+                    aws_access_key_id, aws_secret_access_key, **kw)
+            except Exception as ex:
+                raise NotConfigured(str(ex))
+        else:
+            SignerCls = botocore.auth.AUTH_TYPE_MAPS['s3']
+            # TODO - anon
+            self._signer = SignerCls(botocore.credentials.Credentials(
+                aws_access_key_id, aws_secret_access_key))
+
         self._download_http = httpdownloadhandler(settings).download_request
 
     def download_request(self, request, spider):
@@ -65,12 +80,28 @@ class S3DownloadHandler(object):
         bucket = p.hostname
         path = p.path + '?' + p.query if p.query else p.path
         url = '%s://%s.s3.amazonaws.com%s' % (scheme, bucket, path)
-        signed_headers = self.conn.make_request(
+        if self._signer is not None:
+            import botocore.awsrequest
+            from botocore.vendored.requests.structures import CaseInsensitiveDict
+            print(url, request.headers)
+            awsrequest = botocore.awsrequest.AWSRequest(
                 method=request.method,
-                bucket=bucket,
-                key=unquote(p.path),
-                query_args=unquote(p.query),
-                headers=request.headers,
+                url='%s://s3.amazonaws.com/%s%s' % (scheme, bucket, path),
+                # TODO - move to a header method
+                headers=CaseInsensitiveDict(
+                    (to_unicode(key), to_unicode(b','.join(value)))
+                    for key, value in request.headers.items()),
                 data=request.body)
-        httpreq = request.replace(url=url, headers=signed_headers)
-        return self._download_http(httpreq, spider)
+            self._signer.add_auth(awsrequest)
+            request = request.replace(
+                url=url, headers=awsrequest.headers.items())
+        else:
+            signed_headers = self.conn.make_request(
+                    method=request.method,
+                    bucket=bucket,
+                    key=unquote(p.path),
+                    query_args=unquote(p.query),
+                    headers=request.headers,
+                    data=request.body)
+            request = request.replace(url=url, headers=signed_headers)
+        return self._download_http(request, spider)

tests/test_downloader_handlers.py

@@ -432,13 +432,20 @@ class HttpDownloadHandlerMock(object):
         return request
 
 
-class S3AnonTestCase(unittest.TestCase):
-    try:
-        import boto
-    except ImportError:
-        skip = 'missing boto library'
+class BaseS3TestCase(unittest.TestCase):
     if six.PY3:
-        skip = 'S3 not supported on Py3'
+        try:
+            import botocore
+        except ImportError:
+            skip = 'missing botocore library'
+    else:
+        try:
+            import boto
+        except ImportError:
+            skip = 'missing boto library'
+
+
+class S3AnonTestCase(BaseS3TestCase):
 
     def setUp(self):
         self.s3reqh = S3DownloadHandler(Settings(),
@@ -457,12 +464,6 @@ class S3AnonTestCase(unittest.TestCase):
 
 class S3TestCase(unittest.TestCase):
     download_handler_cls = S3DownloadHandler
-    try:
-        import boto
-    except ImportError:
-        skip = 'missing boto library'
-    if six.PY3:
-        skip = 'S3 not supported on Py3'
 
     # test use same example keys than amazon developer guide
     # http://s3.amazonaws.com/awsdocs/S3/20060301/s3-dg-20060301.pdf
@@ -484,7 +485,7 @@ class S3TestCase(unittest.TestCase):
                 headers={'Date': 'Tue, 27 Mar 2007 19:36:42 +0000'})
         httpreq = self.download_request(req, self.spider)
         self.assertEqual(httpreq.headers['Authorization'], \
-                'AWS 0PN5J17HBGZHT7JJ3X82:xXjDGYUmKxnwqr5KXNPGldn5LbA=')
+                b'AWS 0PN5J17HBGZHT7JJ3X82:xXjDGYUmKxnwqr5KXNPGldn5LbA=')
 
     def test_request_signing2(self):
         # puts an object into the johnsmith bucket.
@@ -495,7 +496,7 @@ class S3TestCase(unittest.TestCase):
             })
         httpreq = self.download_request(req, self.spider)
         self.assertEqual(httpreq.headers['Authorization'], \
-                'AWS 0PN5J17HBGZHT7JJ3X82:hcicpDDvL9SsO6AkvxqmIWkmOuQ=')
+                b'AWS 0PN5J17HBGZHT7JJ3X82:hcicpDDvL9SsO6AkvxqmIWkmOuQ=')
 
     def test_request_signing3(self):
         # lists the content of the johnsmith bucket.
@@ -506,7 +507,7 @@ class S3TestCase(unittest.TestCase):
                     })
         httpreq = self.download_request(req, self.spider)
         self.assertEqual(httpreq.headers['Authorization'], \
-                'AWS 0PN5J17HBGZHT7JJ3X82:jsRt/rhG+Vtp88HrYL706QhE4w4=')
+                b'AWS 0PN5J17HBGZHT7JJ3X82:jsRt/rhG+Vtp88HrYL706QhE4w4=')
 
     def test_request_signing4(self):
         # fetches the access control policy sub-resource for the 'johnsmith' bucket.
@@ -514,7 +515,7 @@ class S3TestCase(unittest.TestCase):
                 method='GET', headers={'Date': 'Tue, 27 Mar 2007 19:44:46 +0000'})
         httpreq = self.download_request(req, self.spider)
         self.assertEqual(httpreq.headers['Authorization'], \
-                'AWS 0PN5J17HBGZHT7JJ3X82:thdUi9VAkzhkniLj96JIrOPGi0g=')
+                b'AWS 0PN5J17HBGZHT7JJ3X82:thdUi9VAkzhkniLj96JIrOPGi0g=')
 
     def test_request_signing5(self):
         # deletes an object from the 'johnsmith' bucket using the
@@ -526,7 +527,7 @@ class S3TestCase(unittest.TestCase):
                     })
         httpreq = self.download_request(req, self.spider)
         self.assertEqual(httpreq.headers['Authorization'], \
-                'AWS 0PN5J17HBGZHT7JJ3X82:k3nL7gH3+PadhTEVn5Ip83xlYzk=')
+                b'AWS 0PN5J17HBGZHT7JJ3X82:k3nL7gH3+PadhTEVn5Ip83xlYzk=')
 
     def test_request_signing6(self):
         # uploads an object to a CNAME style virtual hosted bucket with metadata.
@@ -547,7 +548,7 @@ class S3TestCase(unittest.TestCase):
                     })
         httpreq = self.download_request(req, self.spider)
         self.assertEqual(httpreq.headers['Authorization'], \
-                'AWS 0PN5J17HBGZHT7JJ3X82:C0FlOtU8Ylb9KDTpZqYkZPX91iI=')
+                b'AWS 0PN5J17HBGZHT7JJ3X82:C0FlOtU8Ylb9KDTpZqYkZPX91iI=')
 
     def test_request_signing7(self):
         # ensure that spaces are quoted properly before signing
@@ -561,7 +562,7 @@ class S3TestCase(unittest.TestCase):
         httpreq = self.download_request(req, self.spider)
         self.assertEqual(
             httpreq.headers['Authorization'],
-            'AWS 0PN5J17HBGZHT7JJ3X82:+CfvG8EZ3YccOrRVMXNaK2eKZmM=')
+            b'AWS 0PN5J17HBGZHT7JJ3X82:+CfvG8EZ3YccOrRVMXNaK2eKZmM=')
 
 
 class FTPTestCase(unittest.TestCase):