backend (currently json).
"""
+# pylint: disable-msg=C0103
+
+# C0103: Invalid name, since pylint doesn't see that Dump points to a
+# function and not a constant
import simplejson
import re
-import hmac
from ganeti import errors
+from ganeti import utils
-try:
- from hashlib import sha1
-except ImportError:
- import sha as sha1
-# Check whether the simplejson module supports indentation
_JSON_INDENT = 2
-try:
- simplejson.dumps(1, indent=_JSON_INDENT)
-except TypeError:
- _JSON_INDENT = None
_RE_EOLSP = re.compile('[ \t]+$', re.MULTILINE)
+def _GetJsonDumpers(_encoder_class=simplejson.JSONEncoder):
+ """Returns two JSON functions to serialize data.
+
+ @rtype: (callable, callable)
+ @return: The function to generate a compact form of JSON and another one to
+ generate a more readable, indented form of JSON (if supported)
+
+ """
+ plain_encoder = _encoder_class(sort_keys=True)
+
+ # Check whether the simplejson module supports indentation
+ try:
+ indent_encoder = _encoder_class(indent=_JSON_INDENT, sort_keys=True)
+ except TypeError:
+ # Indentation not supported
+ indent_encoder = plain_encoder
+
+ return (plain_encoder.encode, indent_encoder.encode)
+
+
+(_DumpJson, _DumpJsonIndent) = _GetJsonDumpers()
+
+
def DumpJson(data, indent=True):
"""Serialize a given object.
@return: the string representation of data
"""
- if not indent or _JSON_INDENT is None:
- txt = simplejson.dumps(data)
+ if indent:
+ fn = _DumpJsonIndent
else:
- txt = simplejson.dumps(data, indent=_JSON_INDENT)
+ fn = _DumpJson
- txt = _RE_EOLSP.sub("", txt)
+ txt = _RE_EOLSP.sub("", fn(data))
if not txt.endswith('\n'):
txt += '\n'
+
return txt
return simplejson.loads(txt)
-def DumpSignedJson(data, key, salt=None):
+def DumpSignedJson(data, key, salt=None, key_selector=None):
"""Serialize a given object and authenticate it.
@param data: the data to serialize
@param key: shared hmac key
+ @param key_selector: name/id that identifies the key (in case there are
+ multiple keys in use, e.g. in a multi-cluster environment)
@return: the string representation of data signed by the hmac key
"""
signed_dict = {
'msg': txt,
'salt': salt,
- 'hmac': hmac.new(key, salt + txt, sha1).hexdigest(),
- }
- return DumpJson(signed_dict)
+ }
+
+ if key_selector:
+ signed_dict["key_selector"] = key_selector
+ else:
+ key_selector = ""
+
+ signed_dict["hmac"] = utils.Sha1Hmac(key, txt, salt=salt + key_selector)
+ return DumpJson(signed_dict, indent=False)
-def LoadSignedJson(txt, key, salt_verifier=None):
+
+def LoadSignedJson(txt, key):
"""Verify that a given message was signed with the given key, and load it.
@param txt: json-encoded hmac-signed message
- @param key: shared hmac key
- @param salt_verifier: function taking a salt as input and returning boolean
+ @param key: the shared hmac key or a callable taking one argument (the key
+ selector), which returns the hmac key belonging to the key selector.
+ Typical usage is to pass a reference to the get method of a dict.
@rtype: tuple of original data, string
- @return: original data
+ @return: original data, salt
@raises errors.SignatureError: if the message signature doesn't verify
"""
except KeyError:
raise errors.SignatureError('Invalid external message')
- if salt and not salt_verifier:
- raise errors.SignatureError('Salted message is not verified')
- elif salt_verifier is not None:
- if not salt_verifier(salt):
- raise errors.SignatureError('Invalid salt')
+ if callable(key):
+ # pylint: disable-msg=E1103
+ key_selector = signed_dict.get("key_selector", None)
+ hmac_key = key(key_selector)
+ if not hmac_key:
+ raise errors.SignatureError("No key with key selector '%s' found" %
+ key_selector)
+ else:
+ key_selector = ""
+ hmac_key = key
- if hmac.new(key, salt + msg, sha1).hexdigest() != hmac_sign:
+ if not utils.VerifySha1Hmac(hmac_key, msg, hmac_sign,
+ salt=salt + key_selector):
raise errors.SignatureError('Invalid Signature')
- return LoadJson(msg)
-
-
-def SaltEqualTo(expected):
- """Helper salt verifier function that checks for equality.
-
- @type expected: string
- @param expected: expected salt
- @rtype: function
- @return: salt verifier that returns True if the target salt is "x"
-
- """
- return lambda salt: salt == expected
-
-
-def SaltIn(expected):
- """Helper salt verifier function that checks for membership.
-
- @type expected: collection
- @param expected: collection of possible valid salts
- @rtype: function
- @return: salt verifier that returns True if the salt is in the collection
-
- """
- return lambda salt: salt in expected
-
-
-def SaltInRange(min, max):
- """Helper salt verifier function that checks for integer range.
-
- @type min: integer
- @param min: minimum salt value
- @type max: integer
- @param max: maximum salt value
- @rtype: function
- @return: salt verifier that returns True if the salt is in the min,max range
-
- """
- def _CheckSaltInRange(salt):
- try:
- i_salt = int(salt)
- except (TypeError, ValueError), err:
- return False
-
- return i_salt > min and i_salt < max
- return _CheckSaltInRange
+ return LoadJson(msg), salt
Dump = DumpJson
projects / ganeti-local / blobdiff