[project @ Arch-1:robey@lag.net--2005-master-shake%paramiko--dev--1--patch-66]

fix a test that failed once: the encoding of R or S in dss signatures might not always be exactly 20 bytes
This commit is contained in:
Robey Pointer 2005-10-17 16:36:55 +00:00
parent 6eab0b3b4d
commit 64d89583c7
1 changed files with 9 additions and 2 deletions

View File

@ -88,14 +88,21 @@ class DSSKey (PKey):
dss = DSA.construct((long(self.y), long(self.g), long(self.p), long(self.q), long(self.x)))
# generate a suitable k
qsize = len(util.deflate_long(self.q, 0))
while 1:
while True:
k = util.inflate_long(rpool.get_bytes(qsize), 1)
if (k > 2) and (k < self.q):
break
r, s = dss.sign(util.inflate_long(digest, 1), k)
m = Message()
m.add_string('ssh-dss')
m.add_string(util.deflate_long(r, 0) + util.deflate_long(s, 0))
# apparently, in rare cases, r or s may be shorter than 20 bytes!
rstr = util.deflate_long(r, 0)
sstr = util.deflate_long(s, 0)
if len(rstr) < 20:
rstr = '\x00' * (20 - len(rstr)) + rstr
if len(sstr) < 20:
sstr = '\x00' * (20 - len(sstr)) + sstr
m.add_string(rstr + sstr)
return m
def verify_ssh_sig(self, data, msg):