[or-cvs] [thandy/master 1/2] Fix the interface of RSAKey.sign() to work as documented.

[nickm at torproject.org]

Author: Nick Mathewson <nickm at torproject.org>
Date: Sun, 25 Jul 2010 15:16:30 -0400
Subject: Fix the interface of RSAKey.sign() to work as documented.
Commit: 5f2d07ce78e6443592f84a803fe2adced49ada39

Also, remove the (unused) thandy.formats.Key
---
 lib/thandy/formats.py |   51 +++++++-----------------------------------------
 lib/thandy/keys.py    |   12 +++++++---
 2 files changed, 16 insertions(+), 47 deletions(-)

diff --git a/lib/thandy/formats.py b/lib/thandy/formats.py
index 0eb501b..d6f646a 100644
--- a/lib/thandy/formats.py
+++ b/lib/thandy/formats.py
@@ -295,7 +295,8 @@ def makeSignable(obj):
 
 def sign(signed, key):
     """Add an element to the signatures of 'signed', containing a new signature
-       of the "signed" part.
+       of the "signed" part using 'key'.  Replaces all previous signatures
+       generated with 'key'.
     """
 
     SIGNED_SCHEMA.checkMatch(signed)
@@ -306,11 +307,13 @@ def sign(signed, key):
     keyid = key.getKeyID()
 
     signatures = [ s for s in signatures if s['keyid'] != keyid ]
+    newsignatures = key.sign(signable)
+
+    for method, sig in newsignatures:
+        signatures.append({ 'keyid' : keyid,
+                            'method' : method,
+                            'sig' : sig })
 
-    method, sig = key.sign(signable)
-    signatures.append({ 'keyid' : keyid,
-                        'method' : method,
-                        'sig' : sig })
     signed['signatures'] = signatures
 
 def formatTime(t):
@@ -512,44 +515,6 @@ PACKAGE_SCHEMA = S.Func(checkPackageFormatConsistency, PACKAGE_SCHEMA)
 
 ALL_ROLES = ('timestamp', 'mirrors', 'bundle', 'package', 'master')
 
-class Key:
-    #XXXX UNUSED.
-    def __init__(self, key, roles=()):
-        self.key = key
-        self.roles = []
-        for r,p in roles:
-            self.addRole(r,p)
-
-    def addRole(self, role, path):
-        assert role in ALL_ROLES
-        self.roles.append((role, path))
-
-    def getRoles(self):
-        return self.roles
-
-    @staticmethod
-    def fromJSon(obj):
-        # must match PUBKEY_SCHEMA
-        keytype = obj['_keytype']
-        if keytype == 'rsa':
-            return Key(thandy.keys.RSAKey.fromJSon(obj))
-        else:
-            return None
-
-    def format(self):
-        return self.key.format()
-
-    def getKeyID(self):
-        return self.key.getKeyID()
-
-    def sign(self, obj=None, digest=None):
-        return self.key.sign(obj, digest=digest)
-
-    def checkSignature(self, method, data, signature):
-        ok = self.key.checkSignature(method, data, signature)
-        # XXXX CACHE HERE.
-        return ok
-
 class Keylist(KeyDB):
     def __init__(self):
         KeyDB.__init__(self)
diff --git a/lib/thandy/keys.py b/lib/thandy/keys.py
index 211150a..3385ddb 100644
--- a/lib/thandy/keys.py
+++ b/lib/thandy/keys.py
@@ -23,8 +23,12 @@ class PublicKey:
         self._roles = []
     def format(self):
         raise NotImplemented()
-    def sign(self, data=None, digest=None):
-        # returns a list of method,signature tuples.
+    def sign(self, obj=None, digest=None):
+        """Sign either a JSon object provided in 'obj', or a digest provided
+           in 'digest'.  Return a list of (method name, base64-encoded
+           signature) tuple.
+
+           Requires that this is a private key."""
         raise NotImplemented()
     def checkSignature(self, method, data, signature):
         # returns True, False, or raises UnknownMethod.
@@ -125,7 +129,7 @@ class RSAKey(PublicKey):
     >>> k.getKeyID() == k1.getKeyID()
     True
     >>> s = { 'A B C' : "D", "E" : [ "F", "g", 99] }
-    >>> method, sig = k.sign(obj=s)
+    >>> method, sig = k.sign(obj=s)[0]
     >>> k.checkSignature(method, sig, obj=s)
     True
     >>> s2 = [ s ]
@@ -207,7 +211,7 @@ class RSAKey(PublicKey):
             digest = thandy.formats.getDigest(obj)
         m = _pkcs1_padding(digest, (self.key.size()+1) // 8)
         sig = intToBase64(self.key.sign(m, "")[0])
-        return (method, sig)
+        return [ (method, sig) ]
 
     def checkSignature(self, method, sig, obj=None, digest=None):
         assert _xor(obj == None, digest == None)
-- 
1.7.1