# Copyright (C) 2005-2007, 2009-2011 Nominum, Inc.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
# provided that the above copyright notice and this permission notice
# appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
import struct
import binascii
import dns.rdata
import dns.rdatatype
class SSHFP(dns.rdata.Rdata):
"""SSHFP record
@ivar algorithm: the algorithm
@type algorithm: int
@ivar fp_type: the digest type
@type fp_type: int
@ivar fingerprint: the fingerprint
@type fingerprint: string
@see: draft-ietf-secsh-dns-05.txt"""
__slots__ = ['algorithm', 'fp_type', 'fingerprint']
def __init__(self, rdclass, rdtype, algorithm, fp_type,
fingerprint):
super(SSHFP, self).__init__(rdclass, rdtype)
self.algorithm = algorithm
self.fp_type = fp_type
self.fingerprint = fingerprint
def to_text(self, origin=None, relativize=True, **kw):
return '%d %d %s' % (self.algorithm,
self.fp_type,
dns.rdata._hexify(self.fingerprint,
chunksize=128))
@classmethod
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
algorithm = tok.get_uint8()
fp_type = tok.get_uint8()
chunks = []
while 1:
t = tok.get().unescape()
if t.is_eol_or_eof():
break
if not t.is_identifier():
raise dns.exception.SyntaxError
chunks.append(t.value.encode())
fingerprint = b''.join(chunks)
fingerprint = binascii.unhexlify(fingerprint)
return cls(rdclass, rdtype, algorithm, fp_type, fingerprint)
def to_wire(self, file, compress=None, origin=None):
header = struct.pack("!BB", self.algorithm, self.fp_type)
file.write(header)
file.write(self.fingerprint)
@classmethod
def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
header = struct.unpack("!BB", wire[current: current + 2])
current += 2
rdlen -= 2
fingerprint = wire[current: current + rdlen].unwrap()
return cls(rdclass, rdtype, header[0], header[1], fingerprint)
