plain=string.lower(re.match(r"0x([0-9A-Fa-f]*)l?$", hex(n), re.I).group(1))
return "0x" + plain
+def warn(s):
+ "Warning with file/line number"
+ sys.stderr.write("%s:%d: %s\n"
+ % (fileinput.filename(), fileinput.filelineno(), s))
+
output_type = 'windows'
try:
pass
class UnknownKeyType(Exception):
- def __init__(self, keytype):
- self.keytype = keytype
+ def __init__(self, keytype):
+ self.keytype = keytype
+
+class KeyFormatError(Exception):
+ def __init__(self, msg):
+ self.msg = msg
# Now process all known_hosts input.
for line in fileinput.input(args):
# Common fields
hostpat = fields[0]
- magicnumbers = [] # placeholder
+ keyparams = [] # placeholder
keytype = "" # placeholder
# Grotty heuristic to distinguish known_hosts from known_hosts2:
# Treat as SSH-1-type host key.
# Format: hostpat bits10 exp10 mod10 comment...
# (PuTTY doesn't store the number of bits.)
- magicnumbers = map (long, fields[2:4])
+ keyparams = map (long, fields[2:4])
keytype = "rsa"
else:
subfields.append(data)
blob = blob [struct.calcsize(sizefmt) + size : ]
- # The first field is keytype again, and the rest we can treat as
- # an opaque list of bignums (same numbers and order as stored
- # by PuTTY). (currently embedded keytype is ignored entirely)
- magicnumbers = map (strtolong, subfields[1:])
+ # The first field is keytype again.
+ if subfields[0] != sshkeytype:
+ raise KeyFormatError("""
+ outer and embedded key types do not match: '%s', '%s'
+ """ % (sshkeytype, subfields[1]))
+
+ # Translate key type string into something PuTTY can use, and
+ # munge the rest of the data.
+ if sshkeytype == "ssh-rsa":
+ keytype = "rsa2"
+ # The rest of the subfields we can treat as an opaque list
+ # of bignums (same numbers and order as stored by PuTTY).
+ keyparams = map (strtolong, subfields[1:])
+
+ elif sshkeytype == "ssh-dss":
+ keytype = "dss"
+ # Same again.
+ keyparams = map (strtolong, subfields[1:])
+
+ elif sshkeytype == "ecdsa-sha2-nistp256" \
+ or sshkeytype == "ecdsa-sha2-nistp384" \
+ or sshkeytype == "ecdsa-sha2-nistp521":
+ keytype = sshkeytype
+ # Have to parse this a bit.
+ if len(subfields) > 3:
+ raise KeyFormatError("too many subfields in blob")
+ (curvename, Q) = subfields[1:]
+ # First is yet another copy of the key name.
+ if not re.match("ecdsa-sha2-" + re.escape(curvename),
+ sshkeytype):
+ raise KeyFormatError("key type mismatch ('%s' vs '%s')"
+ % (sshkeytype, curvename))
+ # Second contains key material X and Y (hopefully).
+ # First a magic octet indicating point compression.
+ if struct.unpack("B", Q[0])[0] != 4:
+ # No-one seems to use this.
+ raise KeyFormatError("can't convert point-compressed ECDSA")
+ # Then two equal-length bignums (X and Y).
+ bnlen = len(Q)-1
+ if (bnlen % 1) != 0:
+ raise KeyFormatError("odd-length X+Y")
+ bnlen = bnlen / 2
+ (x,y) = Q[1:bnlen+1], Q[bnlen+1:2*bnlen+1]
+ keyparams = [curvename] + map (strtolong, [x,y])
+
+ elif sshkeytype == "ssh-ed25519":
+ # FIXME: these are always stored point-compressed, which
+ # requires actual maths
+ raise KeyFormatError("can't convert ssh-ed25519 yet, sorry")
- # Translate key type into something PuTTY can use.
- if sshkeytype == "ssh-rsa": keytype = "rsa2"
- elif sshkeytype == "ssh-dss": keytype = "dss"
else:
raise UnknownKeyType(sshkeytype)
# Now print out one line per host pattern, discarding wildcards.
for host in string.split (hostpat, ','):
if re.search (r"[*?!]", host):
- sys.stderr.write("Skipping wildcard host pattern '%s'\n"
- % host)
+ warn("skipping wildcard host pattern '%s'" % host)
continue
elif re.match (r"\|", host):
- sys.stderr.write("Skipping hashed hostname '%s'\n" % host)
+ warn("skipping hashed hostname '%s'" % host)
continue
else:
m = re.match (r"\[([^]]*)\]:(\d*)$", host)
# Slightly bizarre output key format: 'type@port:hostname'
# XXX: does PuTTY do anything useful with literal IP[v4]s?
key = keytype + ("@%d:%s" % (port, host))
- value = string.join (map (longtohex, magicnumbers), ',')
+ # Most of these are numbers, but there's the occasional
+ # string that needs passing through
+ value = string.join (map (
+ lambda x: x if isinstance(x, basestring) else longtohex(x),
+ keyparams), ',')
if output_type == 'unix':
# Unix format.
sys.stdout.write('%s %s\n' % (key, value))
% (winmungestr(key), value))
except UnknownKeyType, k:
- sys.stderr.write("Unknown SSH key type '%s', skipping\n" % k.keytype)
+ warn("unknown SSH key type '%s', skipping" % k.keytype)
+ except KeyFormatError, k:
+ warn("trouble parsing key (%s), skipping" % k.msg)
except BlankInputLine:
pass