def fromString(cls, string):
"""
Load a hashed entry from a string representing a line in a known_hosts
file.
@param string: A complete single line from a I{known_hosts} file,
formatted as defined by OpenSSH.
@type string: L{bytes}
@raise DecodeError: if the key, the hostname, or the is not valid
encoded as valid base64
@raise InvalidEntry: if the entry does not have the right number of
elements and is therefore invalid, or the host/hash portion contains
more items than just the host and hash.
@raise BadKeyError: if the key, once decoded from base64, is not
actually an SSH key.
@return: The newly created L{HashedEntry} instance, initialized with the
information from C{string}.
"""
stuff, keyType, key, comment = _extractCommon(string)
saltAndHash = stuff[len(cls.MAGIC):].split(b"|")
if len(saltAndHash) != 2:
raise InvalidEntry()
hostSalt, hostHash = saltAndHash
self = cls(a2b_base64(hostSalt), a2b_base64(hostHash), keyType, key,
comment)
return self
def _extractCommon(string):
"""
Extract common elements of base64 keys from an entry in a hosts file.
@param string: A known hosts file entry (a single line).
@type string: L{bytes}
@return: a 4-tuple of hostname data (L{bytes}), ssh key type (L{bytes}), key
(L{Key}), and comment (L{bytes} or L{None}). The hostname data is
simply the beginning of the line up to the first occurrence of
whitespace.
@rtype: L{tuple}
"""
elements = string.split(None, 2)
if len(elements) != 3:
raise InvalidEntry()
hostnames, keyType, keyAndComment = elements
splitkey = keyAndComment.split(None, 1)
if len(splitkey) == 2:
keyString, comment = splitkey
comment = comment.rstrip(b"\n")
else:
keyString = splitkey[0]
comment = None
key = Key.fromString(a2b_base64(keyString))
return hostnames, keyType, key, comment
def fromString(cls, string):
"""
Load a hashed entry from a string representing a line in a known_hosts
file.
@raise DecodeError: if the key, the hostname, or the is not valid
encoded as valid base64
@raise InvalidEntry: if the entry does not have the right number of
elements and is therefore invalid, or the host/hash portion contains
more items than just the host and hash.
@raise BadKeyError: if the key, once decoded from base64, is not
actually an SSH key.
"""
stuff, keyType, key, comment = _extractCommon(string)
saltAndHash = stuff[len(cls.MAGIC):].split("|")
if len(saltAndHash) != 2:
raise InvalidEntry()
hostSalt, hostHash = saltAndHash
self = cls(hostSalt.decode("base64"), hostHash.decode("base64"),
keyType, key, comment)
return self
