p2p: work around invalid SHA1D attributes appearing in msn objects

Fixes fd.o#27672

Signed-off-by: Jonny Lamb <jonny.lamb@collabora.co.uk>

2 files changed, 26 insertions, 5 deletions

diff --git a/NEWS b/NEWS
index befbe09..f72d4e7 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,7 @@ Fixes:
   * Signal an error in IOChannel if resolving fails. (fd.o#27554)
   * Don't choke on trailing semicolons in message headers. (fd.o#27556)
   * Allow receiving gzip-encoded soap responses (fd.o#27673)
+  * Work around invalid SHA1D attributes appearing in MSN objects (fd.o#27672)
 
 papyon-0.4.6 (2010-04-08)
 =========================
diff --git a/papyon/p2p.py b/papyon/p2p.py
index 1eff3bf..9058ec8 100644
--- a/papyon/p2p.py
+++ b/papyon/p2p.py
@@ -65,6 +65,30 @@ class MSNObjectType(object):
     LOCATION = 14
     "Location"
 
+def __decode_shad(shad, warning=True):
+    try:
+        shad = base64.b64decode(shad)
+    except TypeError:
+        # See fd.o#27672 for details on this workaround.
+        if ' ' in shad:
+            parts = shad.split(' ')
+
+            # Try the first part.
+            shad = __decode_shad(parts[0], False)
+
+            # Try the second part.
+            if shad is None:
+                shad = __decode_shad(parts[1], False)
+
+        else:
+            # Only display this warning if we're not in a nested call otherwise the
+            # warning will be confusing.
+            if warning:
+                logger.warning("Invalid SHA1D in MSNObject: %s" % shad)
+            shad = None
+
+    return shad
+
 class MSNObject(object):
     "Represents an MSNObject."
     def __init__(self, creator, size, typ, location, friendly,
@@ -156,11 +180,7 @@ class MSNObject(object):
         friendly = base64.b64decode(xml.unescape(element["Friendly"]))
         shad = element.get("SHA1D", None)
         if shad is not None:
-            try:
-                shad = base64.b64decode(shad)
-            except TypeError:
-                logger.warning("Invalid SHA1D in MSNObject: %s" % shad)
-                shad = None
+            shad = __decode_shad(shad)
         shac = element.get("SHA1C", None)
         if shac is not None:
             try: