# HG changeset patch
# User Gustavo Andres Morero <gustavo@netlandish.com>
# Date 1525809883 10800
#      Tue May 08 17:04:43 2018 -0300
# Node ID 8e28084a2d636e07dbb4f695f340cee018e798a6
# Parent  29de1fcd2e5cf37549f221a84fd511db24f83092
updating aws get_auth_link to use boto3.

diff --git a/webutils/aws/secures3.py b/webutils/aws/secures3.py
--- a/webutils/aws/secures3.py
+++ b/webutils/aws/secures3.py
@@ -1,5 +1,6 @@
 import hmac
 import time
+import boto3
 import base64
 import hashlib
 try:
@@ -53,8 +54,8 @@
 
         return (bucket, filename, s.scheme)
 
-    def get_auth_link(self, bucket, filename, 
-                      scheme='http', expires=300, timestamp=None):
+    def get_auth_link(self, bucket, filename, scheme='http',
+                      expires=300, timestamp=None):
         ''' Return a secure S3 link with an expiration on the download.
 
             key: S3 Access Key (login)
@@ -66,23 +67,23 @@
         '''
         filename = quote_plus(filename)
         filename = filename.replace('%2F', '/')
-        path = '/%s/%s' % (bucket, filename)
 
         if timestamp is not None:
-            expire_time = float(timestamp)
+            expires_in = int(timestamp - time.time())
         else:
-            expire_time = time.time() + expires
+            expires_in = expires
 
-        expire_str = '%.0f' % (expire_time)
-        string_to_sign = u'GET\n\n\n%s\n%s' % (expire_str, path)
-        params = {
-            'AWSAccessKeyId': self.key,
-            'Expires': expire_str,
-            'Signature': self.gen_signature(string_to_sign.encode('utf-8')),
-        }
-
-        return '%s://s3.amazonaws.com/%s/%s?%s' % (
-                        scheme, bucket, filename, urlencode(params))
+        s3_client = boto3.client(
+            's3',
+            aws_access_key_id=self.key,
+            aws_secret_access_key=self.secret_key,
+        )
+        url = s3_client.generate_presigned_url(
+            ClientMethod='get_object',
+            Params={'Bucket': bucket, 'Key': filename},
+            ExpiresIn=expires_in,
+        )
+        return url
 
     def get_easy_auth_link(self, url, expires=600):
         ''' url should be the full URL to the secure file hosted on S3.