def _write_private_key(self, tag, f, data, password=None):
f.write('-----BEGIN %s PRIVATE KEY-----\n' % tag)
if password is not None:
# since we only support one cipher here, use it
cipher_name = self._CIPHER_TABLE.keys()[0]
cipher = self._CIPHER_TABLE[cipher_name]['cipher']
keysize = self._CIPHER_TABLE[cipher_name]['keysize']
blocksize = self._CIPHER_TABLE[cipher_name]['blocksize']
mode = self._CIPHER_TABLE[cipher_name]['mode']
salt = randpool.get_bytes(8)
key = util.generate_key_bytes(MD5, salt, password, keysize)
if len(data) % blocksize != 0:
n = blocksize - len(data) % blocksize
#data += randpool.get_bytes(n)
# that would make more sense ^, but it confuses openssh.
data += '\0' * n
data = cipher.new(key, mode, salt).encrypt(data)
f.write('Proc-Type: 4,ENCRYPTED\n')
f.write('DEK-Info: %s,%s\n' % (cipher_name, hexlify(salt).upper()))
f.write('\n')
s = base64.encodestring(data)
# re-wrap to 64-char lines
s = ''.join(s.split('\n'))
s = '\n'.join([s[i:i + 64] for i in range(0, len(s), 64)])
f.write(s)
f.write('\n')
f.write('-----END %s PRIVATE KEY-----\n' % tag)
def _write_private_key(self, tag, f, data, password=None):
f.write('-----BEGIN %s PRIVATE KEY-----\n' % tag)
if password is not None:
cipher_name = list(self._CIPHER_TABLE.keys())[0]
cipher = self._CIPHER_TABLE[cipher_name]['cipher']
keysize = self._CIPHER_TABLE[cipher_name]['keysize']
blocksize = self._CIPHER_TABLE[cipher_name]['blocksize']
mode = self._CIPHER_TABLE[cipher_name]['mode']
salt = os.urandom(blocksize)
key = util.generate_key_bytes(md5, salt, password, keysize)
if len(data) % blocksize != 0:
n = blocksize - len(data) % blocksize
#data += os.urandom(n)
# that would make more sense ^, but it confuses openssh.
data += zero_byte * n
data = cipher.new(key, mode, salt).encrypt(data)
f.write('Proc-Type: 4,ENCRYPTED\n')
f.write('DEK-Info: %s,%s\n' % (cipher_name, u(hexlify(salt)).upper()))
f.write('\n')
s = u(encodebytes(data))
# re-wrap to 64-char lines
s = ''.join(s.split('\n'))
s = '\n'.join([s[i: i + 64] for i in range(0, len(s), 64)])
f.write(s)
f.write('\n')
f.write('-----END %s PRIVATE KEY-----\n' % tag)
def _read_private_key_old_format(cls, headers, data, password):
if 'proc-type' not in headers:
# unencryped: done
return data
# encrypted keyfile: will need a password
proc_type = headers['proc-type']
if proc_type != '4,ENCRYPTED':
raise SSHException(
'Unknown private key structure "{}"'.format(proc_type))
try:
encryption_type, saltstr = headers['dek-info'].split(',')
except:
raise SSHException("Can't parse DEK-info in private key file")
if encryption_type not in cls._CIPHER_TABLE:
raise SSHException(
'Unknown private key cipher "{}"'.format(encryption_type))
# if no password was passed in,
# raise an exception pointing out that we need one
if password is None:
raise PasswordRequiredException('Private key file is encrypted')
cipher = cls._CIPHER_TABLE[encryption_type]['cipher']
keysize = cls._CIPHER_TABLE[encryption_type]['keysize']
mode = cls._CIPHER_TABLE[encryption_type]['mode']
salt = unhexlify(b(saltstr))
key = util.generate_key_bytes(md5, salt, password, keysize)
decryptor = Cipher(cipher(key), mode(salt),
backend=default_backend()).decryptor()
return decryptor.update(data) + decryptor.finalize()
def _write_private_key(self, tag, f, data, password=None):
f.write('-----BEGIN %s PRIVATE KEY-----\n' % tag)
if password is not None:
cipher_name = list(self._CIPHER_TABLE.keys())[0]
cipher = self._CIPHER_TABLE[cipher_name]['cipher']
keysize = self._CIPHER_TABLE[cipher_name]['keysize']
blocksize = self._CIPHER_TABLE[cipher_name]['blocksize']
mode = self._CIPHER_TABLE[cipher_name]['mode']
salt = os.urandom(blocksize)
key = util.generate_key_bytes(md5, salt, password, keysize)
if len(data) % blocksize != 0:
n = blocksize - len(data) % blocksize
#data += os.urandom(n)
# that would make more sense ^, but it confuses openssh.
data += zero_byte * n
data = cipher.new(key, mode, salt).encrypt(data)
f.write('Proc-Type: 4,ENCRYPTED\n')
f.write('DEK-Info: %s,%s\n' %
(cipher_name, u(hexlify(salt)).upper()))
f.write('\n')
s = u(encodebytes(data))
# re-wrap to 64-char lines
s = ''.join(s.split('\n'))
s = '\n'.join([s[i:i + 64] for i in range(0, len(s), 64)])
f.write(s)
f.write('\n')
f.write('-----END %s PRIVATE KEY-----\n' % tag)
def test_1_generate_key_bytes(self):
from Crypto.Hash import MD5
key = util.generate_key_bytes(MD5, '\x01\x02\x03\x04',
'happy birthday', 30)
exp = unhexlify(
'61E1F272F4C1C4561586BD322498C0E924672780F47BB37DDA7D54019E64')
self.assertEquals(exp, key)
def _write_private_key(self, tag, f, data, password=None):
f.write('-----BEGIN %s PRIVATE KEY-----\n' % tag)
if password is not None:
# since we only support one cipher here, use it
cipher_name = self._CIPHER_TABLE.keys()[0]
cipher = self._CIPHER_TABLE[cipher_name]['cipher']
keysize = self._CIPHER_TABLE[cipher_name]['keysize']
blocksize = self._CIPHER_TABLE[cipher_name]['blocksize']
mode = self._CIPHER_TABLE[cipher_name]['mode']
salt = randpool.get_bytes(8)
key = util.generate_key_bytes(MD5, salt, password, keysize)
if len(data) % blocksize != 0:
n = blocksize - len(data) % blocksize
#data += randpool.get_bytes(n)
# that would make more sense ^, but it confuses openssh.
data += '\0' * n
data = cipher.new(key, mode, salt).encrypt(data)
f.write('Proc-Type: 4,ENCRYPTED\n')
f.write('DEK-Info: %s,%s\n' % (cipher_name, hexlify(salt).upper()))
f.write('\n')
s = base64.encodestring(data)
# re-wrap to 64-char lines
s = ''.join(s.split('\n'))
s = '\n'.join([s[i : i+64] for i in range(0, len(s), 64)])
f.write(s)
f.write('\n')
f.write('-----END %s PRIVATE KEY-----\n' % tag)
def _read_private_key(self, tag, f, password=None):
lines = f.readlines()
start = 0
beginning_of_key = "-----BEGIN " + tag + " PRIVATE KEY-----"
while start < len(lines) and lines[start].strip() != beginning_of_key:
start += 1
if start >= len(lines):
raise SSHException("not a valid " + tag + " private key file")
# parse any headers first
headers = {}
start += 1
while start < len(lines):
l = lines[start].split(": ")
if len(l) == 1:
break
headers[l[0].lower()] = l[1].strip()
start += 1
# find end
end = start
ending_of_key = "-----END " + tag + " PRIVATE KEY-----"
while end < len(lines) and lines[end].strip() != ending_of_key:
end += 1
# if we trudged to the end of the file, just try to cope.
try:
data = decodebytes(b("".join(lines[start:end])))
except base64.binascii.Error as e:
raise SSHException("base64 decoding error: " + str(e))
if "proc-type" not in headers:
# unencryped: done
return data
# encrypted keyfile: will need a password
proc_type = headers["proc-type"]
if proc_type != "4,ENCRYPTED":
raise SSHException(
'Unknown private key structure "{}"'.format(proc_type)
)
try:
encryption_type, saltstr = headers["dek-info"].split(",")
except:
raise SSHException("Can't parse DEK-info in private key file")
if encryption_type not in self._CIPHER_TABLE:
raise SSHException(
'Unknown private key cipher "{}"'.format(encryption_type)
)
# if no password was passed in,
# raise an exception pointing out that we need one
if password is None:
raise PasswordRequiredException("Private key file is encrypted")
cipher = self._CIPHER_TABLE[encryption_type]["cipher"]
keysize = self._CIPHER_TABLE[encryption_type]["keysize"]
mode = self._CIPHER_TABLE[encryption_type]["mode"]
salt = unhexlify(b(saltstr))
key = util.generate_key_bytes(md5, salt, password, keysize)
decryptor = Cipher(
cipher(key), mode(salt), backend=default_backend()
).decryptor()
return decryptor.update(data) + decryptor.finalize()
def _read_private_key(self, tag, f, password=None):
lines = f.readlines()
start = 0
beginning_of_key = '-----BEGIN ' + tag + ' PRIVATE KEY-----'
while start < len(lines) and lines[start].strip() != beginning_of_key:
start += 1
if start >= len(lines):
raise SSHException('not a valid ' + tag + ' private key file')
# parse any headers first
headers = {}
start += 1
while start < len(lines):
l = lines[start].split(': ')
if len(l) == 1:
break
headers[l[0].lower()] = l[1].strip()
start += 1
# find end
end = start
ending_of_key = '-----END ' + tag + ' PRIVATE KEY-----'
while end < len(lines) and lines[end].strip() != ending_of_key:
end += 1
# if we trudged to the end of the file, just try to cope.
try:
data = decodebytes(b(''.join(lines[start:end])))
except base64.binascii.Error as e:
raise SSHException('base64 decoding error: ' + str(e))
if 'proc-type' not in headers:
# unencryped: done
return data
# encrypted keyfile: will need a password
if headers['proc-type'] != '4,ENCRYPTED':
raise SSHException(
'Unknown private key structure "%s"' % headers['proc-type'])
try:
encryption_type, saltstr = headers['dek-info'].split(',')
except:
raise SSHException("Can't parse DEK-info in private key file")
if encryption_type not in self._CIPHER_TABLE:
raise SSHException(
'Unknown private key cipher "%s"' % encryption_type)
# if no password was passed in,
# raise an exception pointing out that we need one
if password is None:
raise PasswordRequiredException('Private key file is encrypted')
cipher = self._CIPHER_TABLE[encryption_type]['cipher']
keysize = self._CIPHER_TABLE[encryption_type]['keysize']
mode = self._CIPHER_TABLE[encryption_type]['mode']
salt = unhexlify(b(saltstr))
key = util.generate_key_bytes(md5, salt, password, keysize)
decryptor = Cipher(
cipher(key), mode(salt), backend=default_backend()
).decryptor()
return decryptor.update(data) + decryptor.finalize()
def _read_private_key(self, tag, f, password=None):
lines = f.readlines()
start = 0
beginning_of_key = '-----BEGIN ' + tag + ' PRIVATE KEY-----'
while start < len(lines) and lines[start].strip() != beginning_of_key:
start += 1
if start >= len(lines):
raise SSHException('not a valid ' + tag + ' private key file')
# parse any headers first
headers = {}
start += 1
while start < len(lines):
l = lines[start].split(': ')
if len(l) == 1:
break
headers[l[0].lower()] = l[1].strip()
start += 1
# find end
end = start
ending_of_key = '-----END ' + tag + ' PRIVATE KEY-----'
while end < len(lines) and lines[end].strip() != ending_of_key:
end += 1
# if we trudged to the end of the file, just try to cope.
try:
data = decodebytes(b(''.join(lines[start:end])))
except base64.binascii.Error as e:
raise SSHException('base64 decoding error: ' + str(e))
if 'proc-type' not in headers:
# unencryped: done
return data
# encrypted keyfile: will need a password
if headers['proc-type'] != '4,ENCRYPTED':
raise SSHException('Unknown private key structure "%s"' %
headers['proc-type'])
try:
encryption_type, saltstr = headers['dek-info'].split(',')
except:
raise SSHException("Can't parse DEK-info in private key file")
if encryption_type not in self._CIPHER_TABLE:
raise SSHException('Unknown private key cipher "%s"' %
encryption_type)
# if no password was passed in,
# raise an exception pointing out that we need one
if password is None:
raise PasswordRequiredException('Private key file is encrypted')
cipher = self._CIPHER_TABLE[encryption_type]['cipher']
keysize = self._CIPHER_TABLE[encryption_type]['keysize']
mode = self._CIPHER_TABLE[encryption_type]['mode']
salt = unhexlify(b(saltstr))
key = util.generate_key_bytes(md5, salt, password, keysize)
decryptor = Cipher(cipher(key), mode(salt),
backend=default_backend()).decryptor()
return decryptor.update(data) + decryptor.finalize()
def _write_private_key_file(self, tag, filename, data, password=None):
"""
Write an SSH2-format private key file in a form that can be read by
paramiko or openssh. If no password is given, the key is written in
a trivially-encoded format (base64) which is completely insecure. If
a password is given, DES-EDE3-CBC is used.
@param tag: C{"RSA"} or C{"DSA"}, the tag used to mark the data block.
@type tag: str
@param filename: name of the file to write.
@type filename: str
@param data: data blob that makes up the private key.
@type data: str
@param password: an optional password to use to encrypt the file.
@type password: str
@raise IOError: if there was an error writing the file.
"""
f = open(filename, 'w', 0600)
# grrr... the mode doesn't always take hold
os.chmod(filename, 0600)
f.write('-----BEGIN %s PRIVATE KEY-----\n' % tag)
if password is not None:
# since we only support one cipher here, use it
cipher_name = self._CIPHER_TABLE.keys()[0]
cipher = self._CIPHER_TABLE[cipher_name]['cipher']
keysize = self._CIPHER_TABLE[cipher_name]['keysize']
blocksize = self._CIPHER_TABLE[cipher_name]['blocksize']
mode = self._CIPHER_TABLE[cipher_name]['mode']
salt = randpool.get_bytes(8)
key = util.generate_key_bytes(MD5, salt, password, keysize)
if len(data) % blocksize != 0:
n = blocksize - len(data) % blocksize
#data += randpool.get_bytes(n)
# that would make more sense ^, but it confuses openssh.
data += '\0' * n
data = cipher.new(key, mode, salt).encrypt(data)
f.write('Proc-Type: 4,ENCRYPTED\n')
f.write('DEK-Info: %s,%s\n' % (cipher_name, util.hexify(salt)))
f.write('\n')
s = base64.encodestring(data)
# re-wrap to 64-char lines
s = ''.join(s.split('\n'))
s = '\n'.join([s[i:i + 64] for i in range(0, len(s), 64)])
f.write(s)
f.write('\n')
f.write('-----END %s PRIVATE KEY-----\n' % tag)
f.close()
def _write_private_key_file(self, tag, filename, data, password=None):
"""
Write an SSH2-format private key file in a form that can be read by
paramiko or openssh. If no password is given, the key is written in
a trivially-encoded format (base64) which is completely insecure. If
a password is given, DES-EDE3-CBC is used.
@param tag: C{"RSA"} or C{"DSA"}, the tag used to mark the data block.
@type tag: str
@param filename: name of the file to write.
@type filename: str
@param data: data blob that makes up the private key.
@type data: str
@param password: an optional password to use to encrypt the file.
@type password: str
@raise IOError: if there was an error writing the file.
"""
f = open(filename, 'w', 0600)
# grrr... the mode doesn't always take hold
os.chmod(filename, 0600)
f.write('-----BEGIN %s PRIVATE KEY-----\n' % tag)
if password is not None:
# since we only support one cipher here, use it
cipher_name = self._CIPHER_TABLE.keys()[0]
cipher = self._CIPHER_TABLE[cipher_name]['cipher']
keysize = self._CIPHER_TABLE[cipher_name]['keysize']
blocksize = self._CIPHER_TABLE[cipher_name]['blocksize']
mode = self._CIPHER_TABLE[cipher_name]['mode']
salt = randpool.get_bytes(8)
key = util.generate_key_bytes(MD5, salt, password, keysize)
if len(data) % blocksize != 0:
n = blocksize - len(data) % blocksize
#data += randpool.get_bytes(n)
# that would make more sense ^, but it confuses openssh.
data += '\0' * n
data = cipher.new(key, mode, salt).encrypt(data)
f.write('Proc-Type: 4,ENCRYPTED\n')
f.write('DEK-Info: %s,%s\n' % (cipher_name, util.hexify(salt)))
f.write('\n')
s = base64.encodestring(data)
# re-wrap to 64-char lines
s = ''.join(s.split('\n'))
s = '\n'.join([s[i : i+64] for i in range(0, len(s), 64)])
f.write(s)
f.write('\n')
f.write('-----END %s PRIVATE KEY-----\n' % tag)
f.close()
def _read_private_key(self, tag, f, password=None):
lines = f.readlines()
start = 0
while (start < len(lines)) and (lines[start].strip() != "-----BEGIN " + tag + " PRIVATE KEY-----"):
start += 1
if start >= len(lines):
raise SSHException("not a valid " + tag + " private key file")
# parse any headers first
headers = {}
start += 1
while start < len(lines):
l = lines[start].split(": ")
if len(l) == 1:
break
headers[l[0].lower()] = l[1].strip()
start += 1
# find end
end = start
while (lines[end].strip() != "-----END " + tag + " PRIVATE KEY-----") and (end < len(lines)):
end += 1
# if we trudged to the end of the file, just try to cope.
try:
data = base64.decodestring("".join(lines[start:end]))
except base64.binascii.Error as e:
raise SSHException("base64 decoding error: " + str(e))
if "proc-type" not in headers:
# unencryped: done
return data
# encrypted keyfile: will need a password
if headers["proc-type"] != "4,ENCRYPTED":
raise SSHException('Unknown private key structure "%s"' % headers["proc-type"])
try:
encryption_type, saltstr = headers["dek-info"].split(",")
except:
raise SSHException("Can't parse DEK-info in private key file")
if encryption_type not in self._CIPHER_TABLE:
raise SSHException('Unknown private key cipher "%s"' % encryption_type)
# if no password was passed in, raise an exception pointing out that we need one
if password is None:
raise PasswordRequiredException("Private key file is encrypted")
cipher = self._CIPHER_TABLE[encryption_type]["cipher"]
keysize = self._CIPHER_TABLE[encryption_type]["keysize"]
mode = self._CIPHER_TABLE[encryption_type]["mode"]
salt = unhexlify(saltstr)
key = util.generate_key_bytes(MD5, salt, password, keysize)
return cipher.new(key, mode, salt).decrypt(data)
def _read_private_key_old_format(self, lines, end, password):
start = 0
# parse any headers first
headers = {}
start += 1
while start < len(lines):
l = lines[start].split(': ')
if len(l) == 1:
break
headers[l[0].lower()] = l[1].strip()
start += 1
# if we trudged to the end of the file, just try to cope.
try:
data = decodebytes(b(''.join(lines[start:end])))
except base64.binascii.Error as e:
raise SSHException('base64 decoding error: ' + str(e))
if 'proc-type' not in headers:
# unencryped: done
return data
# encrypted keyfile: will need a password
proc_type = headers['proc-type']
if proc_type != '4,ENCRYPTED':
raise SSHException(
'Unknown private key structure "{}"'.format(proc_type))
try:
encryption_type, saltstr = headers['dek-info'].split(',')
except:
raise SSHException("Can't parse DEK-info in private key file")
if encryption_type not in self._CIPHER_TABLE:
raise SSHException(
'Unknown private key cipher "{}"'.format(encryption_type))
# if no password was passed in,
# raise an exception pointing out that we need one
if password is None:
raise PasswordRequiredException('Private key file is encrypted')
cipher = self._CIPHER_TABLE[encryption_type]['cipher']
keysize = self._CIPHER_TABLE[encryption_type]['keysize']
mode = self._CIPHER_TABLE[encryption_type]['mode']
salt = unhexlify(b(saltstr))
key = util.generate_key_bytes(md5, salt, password, keysize)
decryptor = Cipher(cipher(key), mode(salt),
backend=default_backend()).decryptor()
return decryptor.update(data) + decryptor.finalize()
class PKey(object):
"""
Base class for public keys.
"""
# known encryption types for private key files:
_CIPHER_TABLE = {
'AES-128-CBC': {
'cipher': AES,
'keysize': 16,
'blocksize': 16,
'mode': AES.MODE_CBC
},
'DES-EDE3-CBC': {
'cipher': DES3,
'keysize': 24,
'blocksize': 8,
'mode': DES3.MODE_CBC
},
}
def __init__(self, msg=None, data=None):
"""
Create a new instance of this public key type. If ``msg`` is given,
the key's public part(s) will be filled in from the message. If
``data`` is given, the key's public part(s) will be filled in from
the string.
:param .Message msg:
an optional SSH `.Message` containing a public key of this type.
:param str data: an optional string containing a public key of this type
:raises SSHException:
if a key cannot be created from the ``data`` or ``msg`` given, or
no key was passed in.
"""
pass
def __str__(self):
"""
Return a string of an SSH `.Message` made up of the public part(s) of
this key. This string is suitable for passing to `__init__` to
re-create the key object later.
"""
return ''
def __cmp__(self, other):
"""
Compare this key to another. Returns 0 if this key is equivalent to
the given key, or non-0 if they are different. Only the public parts
of the key are compared, so a public key will compare equal to its
corresponding private key.
:param .Pkey other: key to compare to.
"""
hs = hash(self)
ho = hash(other)
if hs != ho:
return cmp(hs, ho)
return cmp(str(self), str(other))
def get_name(self):
"""
Return the name of this private key implementation.
:return:
name of this private key type, in SSH terminology, as a `str` (for
example, ``"ssh-rsa"``).
"""
return ''
def get_bits(self):
"""
Return the number of significant bits in this key. This is useful
for judging the relative security of a key.
:return: bits in the key (as an `int`)
"""
return 0
def can_sign(self):
"""
Return ``True`` if this key has the private part necessary for signing
data.
"""
return False
def get_fingerprint(self):
"""
Return an MD5 fingerprint of the public part of this key. Nothing
secret is revealed.
:return:
a 16-byte `string <str>` (binary) of the MD5 fingerprint, in SSH
format.
"""
return MD5.new(str(self)).digest()
def get_base64(self):
"""
Return a base64 string containing the public part of this key. Nothing
secret is revealed. This format is compatible with that used to store
public key files or recognized host keys.
:return: a base64 `string <str>` containing the public part of the key.
"""
return base64.encodestring(str(self)).replace('\n', '')
def sign_ssh_data(self, rng, data):
"""
Sign a blob of data with this private key, and return a `.Message`
representing an SSH signature message.
:param .Crypto.Util.rng.RandomPool rng: a secure random number generator.
:param str data: the data to sign.
:return: an SSH signature `message <.Message>`.
"""
return ''
def verify_ssh_sig(self, data, msg):
"""
Given a blob of data, and an SSH message representing a signature of
that data, verify that it was signed with this key.
:param str data: the data that was signed.
:param .Message msg: an SSH signature message
:return:
``True`` if the signature verifies correctly; ``False`` otherwise.
"""
return False
def from_private_key_file(cls, filename, password=None):
"""
Create a key object by reading a private key file. If the private
key is encrypted and ``password`` is not ``None``, the given password
will be used to decrypt the key (otherwise `.PasswordRequiredException`
is thrown). Through the magic of Python, this factory method will
exist in all subclasses of PKey (such as `.RSAKey` or `.DSSKey`), but
is useless on the abstract PKey class.
:param str filename: name of the file to read
:param str password: an optional password to use to decrypt the key file,
if it's encrypted
:return: a new `.PKey` based on the given private key
:raises IOError: if there was an error reading the file
:raises PasswordRequiredException: if the private key file is
encrypted, and ``password`` is ``None``
:raises SSHException: if the key file is invalid
"""
key = cls(filename=filename, password=password)
return key
from_private_key_file = classmethod(from_private_key_file)
def from_private_key(cls, file_obj, password=None):
"""
Create a key object by reading a private key from a file (or file-like)
object. If the private key is encrypted and ``password`` is not ``None``,
the given password will be used to decrypt the key (otherwise
`.PasswordRequiredException` is thrown).
:param file file_obj: the file to read from
:param str password:
an optional password to use to decrypt the key, if it's encrypted
:return: a new `.PKey` based on the given private key
:raises IOError: if there was an error reading the key
:raises PasswordRequiredException: if the private key file is encrypted,
and ``password`` is ``None``
:raises SSHException: if the key file is invalid
"""
key = cls(file_obj=file_obj, password=password)
return key
from_private_key = classmethod(from_private_key)
def write_private_key_file(self, filename, password=None):
"""
Write private key contents into a file. If the password is not
``None``, the key is encrypted before writing.
:param str filename: name of the file to write
:param str password:
an optional password to use to encrypt the key file
:raises IOError: if there was an error writing the file
:raises SSHException: if the key is invalid
"""
raise Exception('Not implemented in PKey')
def write_private_key(self, file_obj, password=None):
"""
Write private key contents into a file (or file-like) object. If the
password is not ``None``, the key is encrypted before writing.
:param file file_obj: the file object to write into
:param str password: an optional password to use to encrypt the key
:raises IOError: if there was an error writing to the file
:raises SSHException: if the key is invalid
"""
raise Exception('Not implemented in PKey')
def _read_private_key_file(self, tag, filename, password=None):
"""
Read an SSH2-format private key file, looking for a string of the type
``"BEGIN xxx PRIVATE KEY"`` for some ``xxx``, base64-decode the text we
find, and return it as a string. If the private key is encrypted and
``password`` is not ``None``, the given password will be used to decrypt
the key (otherwise `.PasswordRequiredException` is thrown).
:param str tag: ``"RSA"`` or ``"DSA"``, the tag used to mark the data block.
:param str filename: name of the file to read.
:param str password:
an optional password to use to decrypt the key file, if it's
encrypted.
:return: data blob (`str`) that makes up the private key.
:raises IOError: if there was an error reading the file.
:raises PasswordRequiredException: if the private key file is
encrypted, and ``password`` is ``None``.
:raises SSHException: if the key file is invalid.
"""
f = open(filename, 'r')
data = self._read_private_key(tag, f, password)
f.close()
return data
def _read_private_key(self, tag, f, password=None):
lines = f.readlines()
start = 0
while (start < len(lines)) and (lines[start].strip() != '-----BEGIN ' +
tag + ' PRIVATE KEY-----'):
start += 1
if start >= len(lines):
raise SSHException('not a valid ' + tag + ' private key file')
# parse any headers first
headers = {}
start += 1
while start < len(lines):
l = lines[start].split(': ')
if len(l) == 1:
break
headers[l[0].lower()] = l[1].strip()
start += 1
# find end
end = start
while (lines[end].strip() !=
'-----END ' + tag + ' PRIVATE KEY-----') and (end < len(lines)):
end += 1
# if we trudged to the end of the file, just try to cope.
try:
data = base64.decodestring(''.join(lines[start:end]))
except base64.binascii.Error, e:
raise SSHException('base64 decoding error: ' + str(e))
if 'proc-type' not in headers:
# unencryped: done
return data
# encrypted keyfile: will need a password
if headers['proc-type'] != '4,ENCRYPTED':
raise SSHException('Unknown private key structure "%s"' %
headers['proc-type'])
try:
encryption_type, saltstr = headers['dek-info'].split(',')
except:
raise SSHException('Can\'t parse DEK-info in private key file')
if encryption_type not in self._CIPHER_TABLE:
raise SSHException('Unknown private key cipher "%s"' %
encryption_type)
# if no password was passed in, raise an exception pointing out that we need one
if password is None:
raise PasswordRequiredException('Private key file is encrypted')
cipher = self._CIPHER_TABLE[encryption_type]['cipher']
keysize = self._CIPHER_TABLE[encryption_type]['keysize']
mode = self._CIPHER_TABLE[encryption_type]['mode']
salt = unhexlify(saltstr)
key = util.generate_key_bytes(MD5, salt, password, keysize)
return cipher.new(key, mode, salt).decrypt(data)
def test_1_generate_key_bytes(self):
from Crypto.Hash import MD5
key = util.generate_key_bytes(MD5, x1234, 'happy birthday', 30)
exp = b'\x61\xE1\xF2\x72\xF4\xC1\xC4\x56\x15\x86\xBD\x32\x24\x98\xC0\xE9\x24\x67\x27\x80\xF4\x7B\xB3\x7D\xDA\x7D\x54\x01\x9E\x64'
self.assertEqual(exp, key)
def test_1_generate_key_bytes(self):
key = util.generate_key_bytes(md5, x1234, "happy birthday", 30)
exp = (
b"\x61\xE1\xF2\x72\xF4\xC1\xC4\x56\x15\x86\xBD\x32\x24\x98\xC0\xE9\x24\x67\x27\x80\xF4\x7B\xB3\x7D\xDA\x7D\x54\x01\x9E\x64"
)
self.assertEqual(exp, key)
def test_1_generate_key_bytes(self):
from Crypto.Hash import MD5
key = util.generate_key_bytes(MD5, '\x01\x02\x03\x04', 'happy birthday', 30)
exp = unhexlify('61E1F272F4C1C4561586BD322498C0E924672780F47BB37DDA7D54019E64')
self.assertEquals(exp, key)
def test_generate_key_bytes(self):
x1234 = b'\x01\x02\x03\x04'
key = util.generate_key_bytes(md5, x1234, 'happy birthday', 30)
exp = b'\x61\xE1\xF2\x72\xF4\xC1\xC4\x56\x15\x86\xBD\x32\x24\x98\xC0\xE9\x24\x67\x27\x80\xF4\x7B\xB3\x7D\xDA\x7D\x54\x01\x9E\x64' # noqa: E501
self.assertEqual(exp, key)
class PKey(object):
"""
Base class for public keys.
"""
# known encryption types for private key files:
_CIPHER_TABLE = {
'DES-EDE3-CBC': {
'cipher': DES3,
'keysize': 24,
'blocksize': 8,
'mode': DES3.MODE_CBC
}
}
def __init__(self, msg=None, data=None):
"""
Create a new instance of this public key type. If C{msg} is given,
the key's public part(s) will be filled in from the message. If
C{data} is given, the key's public part(s) will be filled in from
the string.
@param msg: an optional SSH L{Message} containing a public key of this
type.
@type msg: L{Message}
@param data: an optional string containing a public key of this type
@type data: str
@raise SSHException: if a key cannot be created from the C{data} or
C{msg} given, or no key was passed in.
"""
pass
def __str__(self):
"""
Return a string of an SSH L{Message} made up of the public part(s) of
this key. This string is suitable for passing to L{__init__} to
re-create the key object later.
@return: string representation of an SSH key message.
@rtype: str
"""
return ''
def __cmp__(self, other):
"""
Compare this key to another. Returns 0 if this key is equivalent to
the given key, or non-0 if they are different. Only the public parts
of the key are compared, so a public key will compare equal to its
corresponding private key.
@param other: key to compare to.
@type other: L{PKey}
@return: 0 if the two keys are equivalent, non-0 otherwise.
@rtype: int
"""
hs = hash(self)
ho = hash(other)
if hs != ho:
return cmp(hs, ho)
return cmp(str(self), str(other))
def get_name(self):
"""
Return the name of this private key implementation.
@return: name of this private key type, in SSH terminology (for
example, C{"ssh-rsa"}).
@rtype: str
"""
return ''
def get_bits(self):
"""
Return the number of significant bits in this key. This is useful
for judging the relative security of a key.
@return: bits in the key.
@rtype: int
"""
return 0
def can_sign(self):
"""
Return C{True} if this key has the private part necessary for signing
data.
@return: C{True} if this is a private key.
@rtype: bool
"""
return False
def get_fingerprint(self):
"""
Return an MD5 fingerprint of the public part of this key. Nothing
secret is revealed.
@return: a 16-byte string (binary) of the MD5 fingerprint, in SSH
format.
@rtype: str
"""
return MD5.new(str(self)).digest()
def get_base64(self):
"""
Return a base64 string containing the public part of this key. Nothing
secret is revealed. This format is compatible with that used to store
public key files or recognized host keys.
@return: a base64 string containing the public part of the key.
@rtype: str
"""
return base64.encodestring(str(self)).replace('\n', '')
def sign_ssh_data(self, randpool, data):
"""
Sign a blob of data with this private key, and return a L{Message}
representing an SSH signature message.
@param randpool: a secure random number generator.
@type randpool: L{Crypto.Util.randpool.RandomPool}
@param data: the data to sign.
@type data: str
@return: an SSH signature message.
@rtype: L{Message}
"""
return ''
def verify_ssh_sig(self, data, msg):
"""
Given a blob of data, and an SSH message representing a signature of
that data, verify that it was signed with this key.
@param data: the data that was signed.
@type data: str
@param msg: an SSH signature message
@type msg: L{Message}
@return: C{True} if the signature verifies correctly; C{False}
otherwise.
@rtype: boolean
"""
return False
def from_private_key_file(cls, filename, password=None):
"""
Create a key object by reading a private key file. If the private
key is encrypted and C{password} is not C{None}, the given password
will be used to decrypt the key (otherwise L{PasswordRequiredException}
is thrown). Through the magic of python, this factory method will
exist in all subclasses of PKey (such as L{RSAKey} or L{DSSKey}), but
is useless on the abstract PKey class.
@param filename: name of the file to read
@type filename: str
@param password: an optional password to use to decrypt the key file,
if it's encrypted
@type password: str
@return: a new key object based on the given private key
@rtype: L{PKey}
@raise IOError: if there was an error reading the file
@raise PasswordRequiredException: if the private key file is
encrypted, and C{password} is C{None}
@raise SSHException: if the key file is invalid
"""
key = cls(filename=filename, password=password)
return key
from_private_key_file = classmethod(from_private_key_file)
def from_private_key(cls, file_obj, password=None):
"""
Create a key object by reading a private key from a file (or file-like)
object. If the private key is encrypted and C{password} is not C{None},
the given password will be used to decrypt the key (otherwise
L{PasswordRequiredException} is thrown).
@param file_obj: the file to read from
@type file_obj: file
@param password: an optional password to use to decrypt the key, if it's
encrypted
@type password: str
@return: a new key object based on the given private key
@rtype: L{PKey}
@raise IOError: if there was an error reading the key
@raise PasswordRequiredException: if the private key file is encrypted,
and C{password} is C{None}
@raise SSHException: if the key file is invalid
"""
key = cls(file_obj=file_obj, password=password)
return key
from_private_key = classmethod(from_private_key)
def write_private_key_file(self, filename, password=None):
"""
Write private key contents into a file. If the password is not
C{None}, the key is encrypted before writing.
@param filename: name of the file to write
@type filename: str
@param password: an optional password to use to encrypt the key file
@type password: str
@raise IOError: if there was an error writing the file
@raise SSHException: if the key is invalid
"""
raise Exception('Not implemented in PKey')
def write_private_key(self, file_obj, password=None):
"""
Write private key contents into a file (or file-like) object. If the
password is not C{None}, the key is encrypted before writing.
@param file_obj: the file object to write into
@type file_obj: file
@param password: an optional password to use to encrypt the key
@type password: str
@raise IOError: if there was an error writing to the file
@raise SSHException: if the key is invalid
"""
raise Exception('Not implemented in PKey')
def _read_private_key_file(self, tag, filename, password=None):
"""
Read an SSH2-format private key file, looking for a string of the type
C{"BEGIN xxx PRIVATE KEY"} for some C{xxx}, base64-decode the text we
find, and return it as a string. If the private key is encrypted and
C{password} is not C{None}, the given password will be used to decrypt
the key (otherwise L{PasswordRequiredException} is thrown).
@param tag: C{"RSA"} or C{"DSA"}, the tag used to mark the data block.
@type tag: str
@param filename: name of the file to read.
@type filename: str
@param password: an optional password to use to decrypt the key file,
if it's encrypted.
@type password: str
@return: data blob that makes up the private key.
@rtype: str
@raise IOError: if there was an error reading the file.
@raise PasswordRequiredException: if the private key file is
encrypted, and C{password} is C{None}.
@raise SSHException: if the key file is invalid.
"""
f = open(filename, 'r')
data = self._read_private_key(tag, f, password)
f.close()
return data
def _read_private_key(self, tag, f, password=None):
lines = f.readlines()
start = 0
while (start < len(lines)) and (lines[start].strip() != '-----BEGIN ' +
tag + ' PRIVATE KEY-----'):
start += 1
if start >= len(lines):
raise SSHException('not a valid ' + tag + ' private key file')
# parse any headers first
headers = {}
start += 1
while start < len(lines):
l = lines[start].split(': ')
if len(l) == 1:
break
headers[l[0].lower()] = l[1].strip()
start += 1
# find end
end = start
while (lines[end].strip() !=
'-----END ' + tag + ' PRIVATE KEY-----') and (end < len(lines)):
end += 1
# if we trudged to the end of the file, just try to cope.
try:
data = base64.decodestring(''.join(lines[start:end]))
except base64.binascii.Error, e:
raise SSHException('base64 decoding error: ' + str(e))
if 'proc-type' not in headers:
# unencryped: done
return data
# encrypted keyfile: will need a password
if headers['proc-type'] != '4,ENCRYPTED':
raise SSHException('Unknown private key structure "%s"' %
headers['proc-type'])
try:
encryption_type, saltstr = headers['dek-info'].split(',')
except:
raise SSHException('Can\'t parse DEK-info in private key file')
if encryption_type not in self._CIPHER_TABLE:
raise SSHException('Unknown private key cipher "%s"' %
encryption_type)
# if no password was passed in, raise an exception pointing out that we need one
if password is None:
raise PasswordRequiredException('Private key file is encrypted')
cipher = self._CIPHER_TABLE[encryption_type]['cipher']
keysize = self._CIPHER_TABLE[encryption_type]['keysize']
mode = self._CIPHER_TABLE[encryption_type]['mode']
salt = unhexlify(saltstr)
key = util.generate_key_bytes(MD5, salt, password, keysize)
return cipher.new(key, mode, salt).decrypt(data)
def test_1_generate_key_bytes(self):
key = util.generate_key_bytes(md5, x1234, 'happy birthday', 30)
exp = b'\x61\xE1\xF2\x72\xF4\xC1\xC4\x56\x15\x86\xBD\x32\x24\x98\xC0\xE9\x24\x67\x27\x80\xF4\x7B\xB3\x7D\xDA\x7D\x54\x01\x9E\x64'
self.assertEqual(exp, key)
