diff options
| author | John Dennis <jdennis@redhat.com> | 2010-03-01 18:55:39 -0500 |
|---|---|---|
| committer | Rob Crittenden <rcritten@redhat.com> | 2010-03-04 15:30:16 -0500 |
| commit | 1289285d491caa67edaeab623e9fbcaaf1a253ff (patch) | |
| tree | 305eaf94a8c0fbb0c54f15ea0cb6b3e2e65aa548 /ipaserver | |
| parent | 06e5b8bd6b4648516b34a5c5ae51dbee65946263 (diff) | |
Fix JSON binary encode and decode errors
Traverse the objects passed to JSON for encoding and decoding.
When binary data is seen during encode replace the binary
data with a dict {'__base64__' : base64_encoding_of_binary_value}.
On decode if a dict is seen whose single key is '__base64__' replace
that dict with the base64 decoded value of the key's value.
Diffstat (limited to 'ipaserver')
| -rw-r--r-- | ipaserver/rpcserver.py | 101 |
1 files changed, 99 insertions, 2 deletions
diff --git a/ipaserver/rpcserver.py b/ipaserver/rpcserver.py index ad402cdf..967ee333 100644 --- a/ipaserver/rpcserver.py +++ b/ipaserver/rpcserver.py @@ -33,7 +33,7 @@ from ipalib.rpc import xml_dumps, xml_loads from ipalib.util import make_repr from ipalib.compat import json from wsgiref.util import shift_path_info - +import base64 _not_found_template = """<html> <head> @@ -60,7 +60,6 @@ def not_found(environ, start_response): ) return [output] - def read_input(environ): """ Read the request body from environ['wsgi.input']. @@ -300,6 +299,102 @@ class xmlserver(WSGIExecutioner): return xml_dumps(response, methodresponse=True) +def json_encode_binary(val): + ''' + JSON cannot encode binary values. We encode binary values in Python str + objects and text in Python unicode objects. In order to allow a binary + object to be passed through JSON we base64 encode it thus converting it to + text which JSON can transport. To assure we recognize the value is a base64 + encoded representation of the original binary value and not confuse it with + other text we convert the binary value to a dict in this form: + + {'__base64__' : base64_encoding_of_binary_value} + + This modification of the original input value cannot be done "in place" as + one might first assume (e.g. replacing any binary items in a container + (e.g. list, tuple, dict) with the base64 dict because the container might be + an immutable object (i.e. a tuple). Therefore this function returns a copy + of any container objects it encounters with tuples replaced by lists. This + is O.K. because the JSON encoding will map both lists and tuples to JSON + arrays. + ''' + + if isinstance(val, dict): + new_dict = {} + for k,v in val.items(): + if isinstance(v, str): + new_dict[k] = {'__base64__' : base64.b64encode(v)} + else: + new_dict[k] = json_encode_binary(v) + del val + return new_dict + elif isinstance(val, (list, tuple)): + new_list = [] + n = len(val) + i = 0 + while i < n: + v = val[i] + if isinstance(v, str): + new_list.append({'__base64__' : base64.b64encode(v)}) + else: + new_list.append(json_encode_binary(v)) + i += 1 + del val + return new_list + elif isinstance(val, str): + return {'__base64__' : base64.b64encode(val)} + else: + return val + +def json_decode_binary(val): + ''' + JSON cannot transport binary data. In order to transport binary data we + convert binary data to a form like this: + + {'__base64__' : base64_encoding_of_binary_value} + + see json_encode_binary() + + After JSON had decoded the JSON stream back into a Python object we must + recursively scan the object looking for any dicts which might represent + binary values and replace the dict containing the base64 encoding of the + binary value with the decoded binary value. Unlike the encoding problem + where the input might consist of immutable object, all JSON decoded + container are mutable so the conversion could be done in place. However we + don't modify objects in place because of side effects which may be + dangerous. Thus we elect to spend a few more cycles and avoid the + possibility of unintended side effects in favor of robustness. + ''' + + if isinstance(val, dict): + if val.has_key('__base64__'): + return base64.b64decode(val['__base64__']) + else: + new_dict = {} + for k,v in val.items(): + if isinstance(v, dict) and v.has_key('__base64__'): + new_dict[k] = base64.b64decode(v['__base64__']) + else: + new_dict[k] = json_decode_binary(v) + del val + return new_dict + elif isinstance(val, list): + new_list = [] + n = len(val) + i = 0 + while i < n: + v = val[i] + if isinstance(v, dict) and v.has_key('__base64__'): + binary_val = base64.b64decode(v['__base64__']) + new_list.append(binary_val) + else: + new_list.append(json_decode_binary(v)) + i += 1 + del val + return new_list + else: + return val + class jsonserver(WSGIExecutioner): """ JSON RPC server. @@ -326,6 +421,7 @@ class jsonserver(WSGIExecutioner): error=error, id=_id, ) + response = json_encode_binary(response) return json.dumps(response, sort_keys=True, indent=4) def unmarshal(self, data): @@ -339,6 +435,7 @@ class jsonserver(WSGIExecutioner): raise JSONError(error='Request is missing "method"') if 'params' not in d: raise JSONError(error='Request is missing "params"') + d = json_decode_binary(d) method = d['method'] params = d['params'] _id = d.get('id') |