From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Mon, 18 Oct 2010 04:40:44 +0000 (-0700)
Subject: Support encrypted log items in the cleaner.
X-Git-Url: http://git.vrable.net/?p=bluesky.git;a=commitdiff_plain;h=c1f4367b3c65b01562bc6484226dff0135cd4780

Support encrypted log items in the cleaner.
---

diff --git a/cleaner/cleaner b/cleaner/cleaner
index 009ebe8..95bbb08 100755
--- a/cleaner/cleaner
+++ b/cleaner/cleaner
@@ -15,7 +15,8 @@ from boto.s3.key import Key
 # The BlueSky 'struct cloudlog_header' data type.
 HEADER_FORMAT = '<4s48sb16sQIII'
 HEADER_CRYPTBYTES = 48
-HEADER_MAGIC = 'AgI-'
+HEADER_MAGIC1 = 'AgI-'          # Unencrypted data
+HEADER_MAGIC2 = 'AgI='          # Encrypted data
 HEADER_SIZE = struct.calcsize(HEADER_FORMAT)
 
 class ITEM_TYPE:
@@ -131,9 +132,10 @@ class LogItem:
 
     def __init__(self):
         self.cryptkeys = '\0' * HEADER_CRYPTBYTES
+        self.encrypted = False
 
     def __str__(self):
-        return "<Item ty=%s location=%s size=%d id=%s...>" % (self.type, self.location, self.size, base64.b16encode(self.id).lower()[0:8])
+        return "<Item%s ty=%s location=%s size=%d id=%s...>" % (self.encrypted and '$' or '', self.type, self.location, self.size, base64.b16encode(self.id).lower()[0:8])
 
     @staticmethod
     def random_id():
@@ -149,8 +151,12 @@ class LogItem:
         link_ids = ''.join(link_ids)
         link_locs = ''.join(link_locs)
 
+        if self.encrypted:
+            magic = HEADER_MAGIC2
+        else:
+            magic = HEADER_MAGIC1
         header = struct.pack(HEADER_FORMAT,
-                             HEADER_MAGIC, self.cryptkeys,
+                             magic, self.cryptkeys,
                              ord(self.type), self.id, self.inum,
                              len(self.data), len(link_ids), len(link_locs))
         return header + self.data + link_ids + link_locs
@@ -232,7 +238,7 @@ def parse_item(data):
     header = struct.unpack_from(HEADER_FORMAT, data, 0)
     size = HEADER_SIZE + sum(header[5:8])
 
-    if header[0] != HEADER_MAGIC:
+    if header[0] not in (HEADER_MAGIC1, HEADER_MAGIC2):
         print "Bad header magic!"
         return
 
@@ -241,6 +247,7 @@ def parse_item(data):
         return
 
     item = LogItem()
+    if header[0] == HEADER_MAGIC2: item.encrypted = True
     item.cryptkeys = header[1]
     item.id = header[3]
     item.inum = header[4]
@@ -289,7 +296,7 @@ def parse_log(data, location=None):
     while len(data) - offset >= HEADER_SIZE:
         header = struct.unpack_from(HEADER_FORMAT, data, offset)
         size = HEADER_SIZE + sum(header[5:8])
-        if header[0] != HEADER_MAGIC:
+        if header[0] not in (HEADER_MAGIC1, HEADER_MAGIC2):
             print "Bad header magic!"
             break
         if size + offset > len(data):