def main():
key = 'secretkey'
msg = input('Enter message: ')
hmac = HMAC(key.encode('utf-8'), msg.encode('utf-8'))
hashed = base64.b64encode(hmac.digest())
print('Hashed:', hashed)
got = send_message(msg)
check_hmac = HMAC(key.encode('utf-8'), got.encode('utf-8'))
got_hashed = base64.b64encode(check_hmac.digest())
print('Is not corruped:', got_hashed == hashed)
def _create_empty(self, password):
assert type(password) != unicode
self.f_tag = "PWS3"
self.f_salt = Vault._urandom(32)
self.f_iter = 2048
stretched_password = self._stretch_password(password, self.f_salt, self.f_iter)
self.f_sha_ps = hashlib.sha256(stretched_password).digest()
cipher = TwofishECB(stretched_password)
self.f_b1 = cipher.encrypt(Vault._urandom(16))
self.f_b2 = cipher.encrypt(Vault._urandom(16))
self.f_b3 = cipher.encrypt(Vault._urandom(16))
self.f_b4 = cipher.encrypt(Vault._urandom(16))
key_k = cipher.decrypt(self.f_b1) + cipher.decrypt(self.f_b2)
key_l = cipher.decrypt(self.f_b3) + cipher.decrypt(self.f_b4)
self.f_iv = Vault._urandom(16)
hmac_checker = HMAC(key_l, "", hashlib.sha256)
cipher = TwofishCBC(key_k, self.f_iv)
# No records yet
self.f_hmac = hmac_checker.digest()
def encrypt_and_hmac(self, packet):
"""
Encrypts and signs a Packet() using self.SK_ei and self.SK_ai
:param packet: Unecrypted Packet() with one or more payloads.
:return: Encrypted and signed Packet() with a single payloads.SK
"""
final = Packet(exchange_type=packet.exchange_type, iSPI=packet.iSPI, rSPI=packet.rSPI, message_id=1)
# Set up crypto
iv = os.urandom(16)
ikecrypto = Camellia(self.SK_ei, iv)
ikehash = HMAC(self.SK_ai, digestmod=sha256)
logger.debug('IV: {}'.format(dump(iv)))
# Encrypt
plain = bytes(packet)[const.IKE_HEADER.size:]
ciphertext = ikecrypto.encrypt(plain)
sk = payloads.SK(next_payload=packet.payloads[0]._type, iv=iv, ciphertext=ciphertext)
final.add_payload(sk)
logger.debug(dump(bytes(final)))
# Sign
ikehash.update(bytes(final)[:-MACLEN])
mac = ikehash.digest()[:MACLEN]
sk.mac(mac)
logger.debug(dump(bytes(final)))
return bytes(final)
def db_create_header(self, password, vault):
vault.f_tag = self.db_version_tag
vault.f_salt = vault.urandom(32)
vault.f_iter = 2048
# Database version 4 uses one master password which is random generated
# and secondary passwords to encrypt them.
# XXX What about master normal password ?
rand_p = random_password()
rand_p.password_length = 32
master_passwd = rand_p.generate_password()
stretched_master_password = vault._stretch_password(master_passwd, vault.f_salt, vault.f_iter)
vault.f_sha_ps = hashlib.sha256(stretched_master_password).digest()
cipher = TwofishECB(stretched_master_password)
vault.f_b1 = cipher.encrypt(vault.urandom(16))
vault.f_b2 = cipher.encrypt(vault.urandom(16))
vault.f_b3 = cipher.encrypt(vault.urandom(16))
vault.f_b4 = cipher.encrypt(vault.urandom(16))
key_k = cipher.decrypt(vault.f_b1) + cipher.decrypt(vault.f_b2)
key_l = cipher.decrypt(vault.f_b3) + cipher.decrypt(vault.f_b4)
vault.f_iv = vault.urandom(16)
hmac_checker = HMAC(key_l, "", hashlib.sha256)
# No records yet
vault.f_hmac = hmac_checker.digest()
# Encrypt master password with user one
stretched_user_pass = vault._stretch_password(password, vault.f_salt, vault.f_iter)
user_cipher = TwofishECB(stretched_user_pass)
self.db_v4_passwds = [{'auth': self.db_ptag[0], 'passwd': user_cipher.encrypt(stretched_master_password), 'orig': '1'}]
def verify_message_auth_code(our_mac, msg_mac, ses_key): ## two rounds closes a timing side-channel msg_mac = HMAC_FUNC(ses_key, msg_mac, HMAC_HASH) our_mac = HMAC_FUNC(ses_key, our_mac, HMAC_HASH) msg_mac = msg_mac.digest() our_mac = our_mac.digest() num_val = 0 if (len(msg_mac) != len(our_mac)): return False ## fixed linear-time comparison closes another for i in xrange(len(our_mac)): num_val += (our_mac[i] == msg_mac[i]) return (num_val == len(our_mac))
def encrypt_and_hmac(self, packet):
"""
Encrypts and signs a Packet() using self.SK_ei and self.SK_ai
:param packet: Unecrypted Packet() with one or more payloads.
:return: Encrypted and signed Packet() with a single payloads.SK
"""
final = Packet(exchange_type=packet.exchange_type,
iSPI=packet.iSPI,
rSPI=packet.rSPI,
message_id=1)
# Set up crypto
iv = os.urandom(16)
ikecrypto = Camellia(self.SK_ei, iv)
ikehash = HMAC(self.SK_ai, digestmod=sha256)
logger.debug('IV: {}'.format(dump(iv)))
# Encrypt
plain = bytes(packet)[const.IKE_HEADER.size:]
ciphertext = ikecrypto.encrypt(plain)
sk = payloads.SK(next_payload=packet.payloads[0]._type,
iv=iv,
ciphertext=ciphertext)
final.add_payload(sk)
logger.debug(dump(bytes(final)))
# Sign
ikehash.update(bytes(final)[:-MACLEN])
mac = ikehash.digest()[:MACLEN]
sk.mac(mac)
logger.debug(dump(bytes(final)))
return bytes(final)
def _create_empty(self, password):
assert type(password) != unicode
self.f_tag = 'PWS3'
self.f_salt = Vault._urandom(32)
self.f_iter = 2048
stretched_password = self._stretch_password(password, self.f_salt,
self.f_iter)
self.f_sha_ps = hashlib.sha256(stretched_password).digest()
cipher = TwofishECB(stretched_password)
self.f_b1 = cipher.encrypt(Vault._urandom(16))
self.f_b2 = cipher.encrypt(Vault._urandom(16))
self.f_b3 = cipher.encrypt(Vault._urandom(16))
self.f_b4 = cipher.encrypt(Vault._urandom(16))
key_k = cipher.decrypt(self.f_b1) + cipher.decrypt(self.f_b2)
key_l = cipher.decrypt(self.f_b3) + cipher.decrypt(self.f_b4)
self.f_iv = Vault._urandom(16)
hmac_checker = HMAC(key_l, "", hashlib.sha256)
cipher = TwofishCBC(key_k, self.f_iv)
# No records yet
self.f_hmac = hmac_checker.digest()
def __findHashedHostname(self,hostname):
for (key,salt,res) in self.hashes:
hmac = HMAC(salt, None, sha1)
hmac.update(hostname)
ours = hmac.digest()
if ours == res:
return self.hosts.get(key)
return None
def ae_stretch_iter(start, iterations):
end = bytes(start)
for i in range(iterations):
hs = HMAC(keys[KEYNUM.pin_stretch], msg=end, digestmod=sha256)
end = hs.digest()
return end
def calculate_digest(secret, message, salt):
"""Calculate a SHA-256 HMAC digest for the given data."""
assert isinstance(secret, bytes), "%r is not a byte string." % (secret, )
assert isinstance(message, bytes), "%r is not byte string." % (message, )
assert isinstance(salt, bytes), "%r is not a byte string." % (salt, )
hmacr = HMAC(secret, digestmod=sha256)
hmacr.update(message)
hmacr.update(salt)
return hmacr.digest()
def response(self, challenge):
if(self.server_signature):
self.evaluateOutcome(challenge)
return ""
else:
serverChallenge, salt, iterations = challenge.split(",")
self.server_nonce = serverChallenge[2:]
if self.server_nonce.find(self.client_nonce) != 0:
raise SaslException("Server nonce does not start with client nonce")
self.salt = base64.b64decode(salt[2:])
iterations = int(iterations[2:])
hmac = HMAC(key=self.password.replace("=","=3D").replace(",","=2C"),digestmod=self.algorithm)
hmac.update(self.salt)
hmac.update("\x00\x00\x00\x01")
saltedPassword = hmac.digest()
previous = saltedPassword
for i in range(1,iterations):
hmac = HMAC(key=self.password.replace("=","=3D").replace(",","=2C"),digestmod=self.algorithm)
hmac.update(previous)
previous = hmac.digest()
saltedPassword = ''.join(chr(ord(a) ^ ord(b)) for a,b in zip(saltedPassword,previous))
clientFinalMessageWithoutProof = "c=" + base64.b64encode("n,,") + ",r=" + self.server_nonce
authMessage = self.client_first_message + "," + challenge + "," + clientFinalMessageWithoutProof
clientKey = HMAC(key=saltedPassword,msg="Client Key",digestmod=self.algorithm).digest()
hashFunc = self.algorithm()
hashFunc.update(clientKey)
storedKey = hashFunc.digest()
clientSignature = HMAC(key=storedKey, msg=authMessage, digestmod=self.algorithm).digest()
clientProof = ''.join(chr(ord(a) ^ ord(b)) for a,b in zip(clientKey,clientSignature))
serverKey = HMAC(key=saltedPassword,msg="Server Key",digestmod=self.algorithm).digest()
self.server_signature = HMAC(key=serverKey,msg=authMessage,digestmod=self.algorithm).digest()
return clientFinalMessageWithoutProof + ",p=" + base64.b64encode(clientProof)
def encrypt_sign_bytes(self, raw_msg, encode_func = base64.b64encode): assert(type(raw_msg) == str) ## encrypt, then sign (HMAC = H((K ^ O) | H((K ^ I) | M))) enc_msg = self.encrypt_encode_bytes(raw_msg, null_encode) msg_mac = HMAC_FUNC(self.get_key(), enc_msg, HMAC_HASH) msg_mac = encode_func(msg_mac.digest()) enc_msg = encode_func(enc_msg) return (enc_msg, msg_mac)
def sas(sbNamespace,sbEntityPath,sharedAccessKey,sharedAccessKeyName):
uri = "http://" + sbNamespace + ".servicebus.windows.net/" + sbEntityPath
encodedResourceUri = quote_plus(uri)
expireInSeconds = floor( time.time() + 300 + .5 )
plainSignature = encodedResourceUri + "\n" + str(expireInSeconds)
plainSignature = plainSignature.encode('utf-8')
signed_hmac_sha256 = HMAC(sharedAccessKey,plainSignature,sha256)
digest = signed_hmac_sha256.digest()
encoded_digest = b64encode(digest)
return "SharedAccessSignature sig=%s&se=%s&skn=%s&sr=%s" % (quote_plus(encoded_digest),expireInSeconds, sharedAccessKeyName, encodedResourceUri)
def _sign(self, stringToSign):
"""
Sign a request using the secret key. Reference: U{http://docs.amazonwebservices.com/AmazonS3/latest/dev/RESTAuthentication.html}
@param stringToSign: the string to sign for the request
@type stringToSign: str
@return: Amazon S3-required HMAC signature
@rtype: str
"""
h=HMAC(self.secretKey, digestmod=sha1)
h.update(stringToSign)
return base64.b64encode(h.digest())
def sas(sbNamespace, sbEntityPath, sharedAccessKey, sharedAccessKeyName):
uri = "http://" + sbNamespace + ".servicebus.windows.net/" + sbEntityPath
encodedResourceUri = quote_plus(uri)
expireInSeconds = floor(time.time() + 300 + .5)
plainSignature = encodedResourceUri + "\n" + str(expireInSeconds)
plainSignature = plainSignature.encode('utf-8')
signed_hmac_sha256 = HMAC(sharedAccessKey, plainSignature, sha256)
digest = signed_hmac_sha256.digest()
encoded_digest = b64encode(digest)
return "SharedAccessSignature sig=%s&se=%s&skn=%s&sr=%s" % (
quote_plus(encoded_digest), expireInSeconds, sharedAccessKeyName,
encodedResourceUri)
def verify_hmac(self, data):
"""
Verifies the HMAC signature of an encrypted (SK, 46) payload using self.SK_ar
:param data: bytes(payloads.SK())
:raise IkeError: if calculated signature does not match the one in the payload
"""
hmac = HMAC(self.SK_ar, digestmod=sha256)
hmac_theirs = data[-MACLEN:]
hmac.update(data[:-MACLEN])
hmac_ours = hmac.digest()[:MACLEN]
logger.debug('HMAC verify (ours){} (theirs){}'.format(
binascii.hexlify(hmac_ours), binascii.hexlify(hmac_theirs)))
if hmac_ours != hmac_theirs:
raise IkeError('HMAC verify failed')
def verify_hmac(self, data):
"""
Verifies the HMAC signature of an encrypted (SK, 46) payload using self.SK_ar
:param data: bytes(payloads.SK())
:raise IkeError: if calculated signature does not match the one in the payload
"""
hmac = HMAC(self.SK_ar, digestmod=sha256)
hmac_theirs = data[-MACLEN:]
hmac.update(data[:-MACLEN])
hmac_ours = hmac.digest()[:MACLEN]
logger.debug('HMAC verify (ours){} (theirs){}'.format(
binascii.hexlify(hmac_ours), binascii.hexlify(hmac_theirs)))
if hmac_ours != hmac_theirs:
raise IkeError('HMAC verify failed')
def auth_decrypt_bytes(self, enc_msg, msg_mac, decode_func=base64.b64decode):
assert type(enc_msg) == str
assert type(msg_mac) == str
# auth, then decrypt
msg_mac = decode_func(msg_mac)
enc_msg = decode_func(enc_msg)
our_mac = HMAC_FUNC(self.get_key(), enc_msg, HMAC_HASH)
our_mac = our_mac.digest()
if verify_message_auth_code(our_mac, msg_mac, self.get_key()):
return self.decode_decrypt_bytes(enc_msg, null_decode)
# counts as false
return ""
def ae_mixin_key(keynum, start):
if keynum:
hm = HMAC(keys[keynum], msg=start, digestmod=sha256)
end = hm.digest()
else:
end = bytes(32)
md = sha256()
md.update(keys[KEYNUM.pairing])
md.update(start)
md.update(bytes([keynum]))
md.update(end)
return md.digest()
def auth_decrypt_bytes(self,
enc_msg,
msg_mac,
decode_func=base64.b64decode):
assert (type(enc_msg) == str)
assert (type(msg_mac) == str)
## auth, then decrypt
msg_mac = decode_func(msg_mac)
enc_msg = decode_func(enc_msg)
our_mac = HMAC_FUNC(self.get_key(), enc_msg, HMAC_HASH)
our_mac = our_mac.digest()
if (verify_message_auth_code(our_mac, msg_mac, self.get_key())):
return (self.decode_decrypt_bytes(enc_msg, null_decode))
## counts as false
return ""
def db_create_header(self, password, vault):
vault.f_tag = self.db_version_tag
vault.f_salt = vault.urandom(32)
vault.f_iter = 2048
stretched_password = vault._stretch_password(password, vault.f_salt, vault.f_iter)
vault.f_sha_ps = hashlib.sha256(stretched_password).digest()
cipher = TwofishECB(stretched_password)
vault.f_b1 = cipher.encrypt(vault.urandom(16))
vault.f_b2 = cipher.encrypt(vault.urandom(16))
vault.f_b3 = cipher.encrypt(vault.urandom(16))
vault.f_b4 = cipher.encrypt(vault.urandom(16))
key_k = cipher.decrypt(vault.f_b1) + cipher.decrypt(vault.f_b2)
key_l = cipher.decrypt(vault.f_b3) + cipher.decrypt(vault.f_b4)
vault.f_iv = vault.urandom(16)
hmac_checker = HMAC(key_l, "", hashlib.sha256)
# No records yet
vault.f_hmac = hmac_checker.digest()
def sign_policy(self, key):
hmac = HMAC(key, self.base64_policy(), hashlib.sha1)
return base64.b64encode(hmac.digest())
def prf(key, data, hash_algorithm='sha256'):
hasher = getattr(hashlib, hash_algorithm)
m = HMAC(key, digestmod=hasher)
m.update(data)
return m.digest()
def response(self, challenge):
if (self.server_signature):
self.evaluateOutcome(challenge)
return ""
else:
serverChallenge, salt, iterations = challenge.split(",")
self.server_nonce = serverChallenge[2:]
if self.server_nonce.find(self.client_nonce) != 0:
raise SaslException(
"Server nonce does not start with client nonce")
self.salt = base64.b64decode(salt[2:])
iterations = int(iterations[2:])
hmac = HMAC(key=self.password.replace("=",
"=3D").replace(",", "=2C"),
digestmod=self.algorithm)
hmac.update(self.salt)
hmac.update("\x00\x00\x00\x01")
saltedPassword = hmac.digest()
previous = saltedPassword
for i in range(1, iterations):
hmac = HMAC(key=self.password.replace("=", "=3D").replace(
",", "=2C"),
digestmod=self.algorithm)
hmac.update(previous)
previous = hmac.digest()
saltedPassword = ''.join(
chr(ord(a) ^ ord(b))
for a, b in zip(saltedPassword, previous))
clientFinalMessageWithoutProof = "c=" + base64.b64encode(
"n,,") + ",r=" + self.server_nonce
authMessage = self.client_first_message + "," + challenge + "," + clientFinalMessageWithoutProof
clientKey = HMAC(key=saltedPassword,
msg="Client Key",
digestmod=self.algorithm).digest()
hashFunc = self.algorithm()
hashFunc.update(clientKey)
storedKey = hashFunc.digest()
clientSignature = HMAC(key=storedKey,
msg=authMessage,
digestmod=self.algorithm).digest()
clientProof = ''.join(
chr(ord(a) ^ ord(b))
for a, b in zip(clientKey, clientSignature))
serverKey = HMAC(key=saltedPassword,
msg="Server Key",
digestmod=self.algorithm).digest()
self.server_signature = HMAC(key=serverKey,
msg=authMessage,
digestmod=self.algorithm).digest()
return clientFinalMessageWithoutProof + ",p=" + base64.b64encode(
clientProof)
def auth_decrypt_bytes_utf8(self, (enc_msg, msg_mac), decode_func = base64.b64decode): return (self.auth_decrypt_bytes((enc_msg.encode(UNICODE_ENCODING), msg_mac.encode(UNICODE_ENCODING)), decode_func)) def encrypt_sign_bytes(self, raw_msg, encode_func = base64.b64encode): assert(type(raw_msg) == str) ## encrypt, then sign (HMAC = H((K ^ O) | H((K ^ I) | M))) enc_msg = self.encrypt_encode_bytes(raw_msg, null_encode) msg_mac = HMAC_FUNC(self.get_key(), enc_msg, HMAC_HASH) msg_mac = encode_func(msg_mac.digest()) enc_msg = encode_func(enc_msg) return (enc_msg, msg_mac) def auth_decrypt_bytes(self, (enc_msg, msg_mac), decode_func = base64.b64decode): assert(type(enc_msg) == str) assert(type(msg_mac) == str) ## auth, then decrypt msg_mac = decode_func(msg_mac) enc_msg = decode_func(enc_msg) our_mac = HMAC_FUNC(self.get_key(), enc_msg, HMAC_HASH) our_mac = our_mac.digest() if (verify_message_auth_code(our_mac, msg_mac, self.get_key())): return (self.decode_decrypt_bytes(enc_msg, null_decode)) ## counts as false return ""
def create_hmac(secret, str_to_encode):
new_hmac = HMAC(secret.encode(encoding=utf8),
str_to_encode.encode(encoding=utf8), hashlib.sha256)
return b64encode(new_hmac.digest())
def _read_from_file(self, filename, password):
"""
Initialize all class members by loading the contents of a Vault stored in the given file.
"""
assert type(password) != str
ver3 = VaultVer3()
ver4 = VaultVer4()
# Read begining database tag and set db_ver db file access class
tag = file(filename, 'rb').read(4)
# Auto detect database type for existing vaults
if (ver3.db_test_bg_tag(tag)):
self.db_ver = ver3
elif (ver4.db_test_bg_tag(tag)):
self.db_ver = ver4
else:
raise self.VaultVersionError("Not a PasswordSafe V3 and V4 compatible file")
if self.db_format != self.db_ver.db_format:
if self.db_format == "auto":
self.db_format = self.db_ver.db_format
else:
print("Database version missmatch I was asked to open database with version %s and it's a %s version" % (self.db_format, self.db_ver.db_format))
sys.exit(1)
# Open password database
self.db_ver.db_open(filename)
# Read database header to Vault class fill all required fields
self.db_ver.db_read_header(password, self)
# Get Stretched master password from db
stretched_password = self.db_ver.db_get_stretched_passwd(self, password) # P': the stretched key
my_sha_ps = hashlib.sha256(stretched_password).digest()
if (self.f_sha_ps != my_sha_ps):
raise self.BadPasswordError("Wrong password")
cipher = TwofishECB(stretched_password)
key_k = cipher.decrypt(self.f_b1) + cipher.decrypt(self.f_b2)
key_l = cipher.decrypt(self.f_b3) + cipher.decrypt(self.f_b4)
hmac_checker = HMAC(key_l, "", hashlib.sha256)
cipher = TwofishCBC(key_k, self.f_iv)
# read header
while (True):
field = self._read_field_tlv(cipher)
if not field:
break
if field.raw_type == 0xff:
break
self.header.add_raw_field(field)
hmac_checker.update(field.raw_value)
# read fields
current_record = self.Record()
while (True):
field = self._read_field_tlv(cipher)
if not field:
break
if field.raw_type == 0xff:
self.records.append(current_record)
current_record = self.Record()
else:
hmac_checker.update(field.raw_value)
current_record.add_raw_field(field)
# read HMAC
self.f_hmac = self.db_ver.db_read_data(32) # HMAC: used to verify Vault's integrity
my_hmac = hmac_checker.digest()
if (self.f_hmac != my_hmac):
raise self.VaultFormatError("File integrity check failed")
self.records.sort()
self.db_ver.db_close()
def write_to_file(self, filename, password):
"""
Store contents of this Vault into a file.
"""
assert type(password) != str
_last_save = struct.pack("<L", int(time.time()))
self.header.raw_fields[0x04] = self.Field(0x04, len(_last_save), _last_save)
_what_saved = prog_name+" "+prog_version.encode("utf_8", "replace")
self.header.raw_fields[0x06] = self.Field(0x06, len(_what_saved), _what_saved)
# write to temporary file first
(osfilehandle, tmpfilename) = tempfile.mkstemp('.part', os.path.basename(filename) + ".", os.path.dirname(filename), text=False)
self.db_ver.db_open(tmpfilename, 'wb')
# f_sha_ps should be already defined, why we want to regen it here.
stretched_password = self.db_ver.db_get_stretched_passwd(self, password)
self.f_sha_ps = hashlib.sha256(stretched_password).digest()
self.db_ver.db_write_header(self, password)
cipher = TwofishECB(stretched_password)
key_k = cipher.decrypt(self.f_b1) + cipher.decrypt(self.f_b2)
key_l = cipher.decrypt(self.f_b3) + cipher.decrypt(self.f_b4)
hmac_checker = HMAC(key_l, "", hashlib.sha256)
cipher = TwofishCBC(key_k, self.f_iv)
end_of_record = self.Field(0xff, 0, "")
for field in list(self.header.raw_fields.values()):
self._write_field_tlv(cipher, field)
hmac_checker.update(field.raw_value)
self._write_field_tlv(cipher, end_of_record)
hmac_checker.update(end_of_record.raw_value)
for record in self.records:
for field in list(record.raw_fields.values()):
self._write_field_tlv(cipher, field)
hmac_checker.update(field.raw_value)
self._write_field_tlv(cipher, end_of_record)
hmac_checker.update(end_of_record.raw_value)
self.db_ver.db_end_data()
self.f_hmac = hmac_checker.digest()
self.db_ver.db_write_data(self.f_hmac)
self.db_ver.db_close()
try:
tmpvault = Vault(password, filename=tmpfilename, format=self.db_ver.db_format)
except RuntimeError:
os.remove(tmpfilename)
raise self.VaultFormatError("File integrity check failed")
# after writing the temporary file, replace the original file with it
try:
os.remove(filename)
except OSError:
pass
os.rename(tmpfilename, filename)
# Because we are extending the hashlib module, we need to import all its
# fields to suppport the same uses
from . import tlshashlib
from .compat import compatHMAC
try:
from hmac import compare_digest
__all__ = ["new", "compare_digest", "HMAC"]
except ImportError:
__all__ = ["new", "HMAC"]
try:
from hmac import HMAC, new
# if we can calculate HMAC on MD5, then use the built-in HMAC
# implementation
_val = HMAC(b'some key', b'msg', 'md5')
_val.digest()
del _val
except Exception:
# fallback only when MD5 doesn't work
class HMAC(object):
"""Hacked version of HMAC that works in FIPS mode even with MD5."""
def __init__(self, key, msg=None, digestmod=None):
"""
Initialise the HMAC and hash first portion of data.
msg: data to hash
digestmod: name of hash or object that be used as a hash and be cloned
"""
self.key = key
if digestmod is None:
digestmod = 'md5'
def _read_from_file(self, filename, password):
"""
Initialize all class members by loading the contents of a Vault stored in the given file.
"""
assert type(password) != unicode
filehandle = file(filename, "rb")
# read boilerplate
self.f_tag = filehandle.read(4) # TAG: magic tag
if self.f_tag != "PWS3":
raise self.VaultVersionError("Not a PasswordSafe V3 file")
self.f_salt = filehandle.read(32) # SALT: SHA-256 salt
self.f_iter = struct.unpack("<L", filehandle.read(4))[0] # ITER: SHA-256 keystretch iterations
stretched_password = self._stretch_password(password, self.f_salt, self.f_iter) # P': the stretched key
my_sha_ps = hashlib.sha256(stretched_password).digest()
self.f_sha_ps = filehandle.read(32) # H(P'): SHA-256 hash of stretched passphrase
if self.f_sha_ps != my_sha_ps:
raise self.BadPasswordError("Wrong password")
self.f_b1 = filehandle.read(16) # B1
self.f_b2 = filehandle.read(16) # B2
self.f_b3 = filehandle.read(16) # B3
self.f_b4 = filehandle.read(16) # B4
cipher = TwofishECB(stretched_password)
key_k = cipher.decrypt(self.f_b1) + cipher.decrypt(self.f_b2)
key_l = cipher.decrypt(self.f_b3) + cipher.decrypt(self.f_b4)
self.f_iv = filehandle.read(16) # IV: initialization vector of Twofish CBC
hmac_checker = HMAC(key_l, "", hashlib.sha256)
cipher = TwofishCBC(key_k, self.f_iv)
# read header
while True:
field = self._read_field_tlv(filehandle, cipher)
if not field:
break
if field.raw_type == 0xFF:
break
self.header.add_raw_field(field)
hmac_checker.update(field.raw_value)
# read fields
current_record = self.Record()
while True:
field = self._read_field_tlv(filehandle, cipher)
if not field:
break
if field.raw_type == 0xFF:
self.records.append(current_record)
current_record = self.Record()
else:
hmac_checker.update(field.raw_value)
current_record.add_raw_field(field)
# read HMAC
self.f_hmac = filehandle.read(32) # HMAC: used to verify Vault's integrity
my_hmac = hmac_checker.digest()
if self.f_hmac != my_hmac:
raise self.VaultFormatError("File integrity check failed")
self.records.sort()
filehandle.close()
def prf(self, key, data):
m = HMAC(key, data, digestmod=self.hasher)
return m.digest()
def compute(self, key, data):
m = HMAC(key, data, digestmod=self.hasher)
return m.digest()[:self.hash_size]
def hmac_sha256(secret, msg):
hmac = HMAC(secret, msg=msg, digestmod=hashlib.sha256)
val = hmac.digest()
return val
def write_to_file(self, filename, password):
"""
Store contents of this Vault into a file.
"""
assert type(password) != unicode
_last_save = struct.pack("<L", int(time.time()))
self.header.raw_fields[0x04] = self.Field(0x04, len(_last_save),
_last_save)
_what_saved = "Loxodo 0.0-git".encode("utf_8", "replace")
self.header.raw_fields[0x06] = self.Field(0x06, len(_what_saved),
_what_saved)
# write to temporary file first
(osfilehandle,
tmpfilename) = tempfile.mkstemp('.part',
os.path.basename(filename) + ".",
os.path.dirname(filename),
text=False)
filehandle = os.fdopen(osfilehandle, "wb")
# FIXME: choose new SALT, B1-B4, IV values on each file write? Conflicting Specs!
# write boilerplate
filehandle.write(self.f_tag)
filehandle.write(self.f_salt)
filehandle.write(struct.pack("<L", self.f_iter))
stretched_password = self._stretch_password(password, self.f_salt,
self.f_iter)
self.f_sha_ps = hashlib.sha256(stretched_password).digest()
filehandle.write(self.f_sha_ps)
filehandle.write(self.f_b1)
filehandle.write(self.f_b2)
filehandle.write(self.f_b3)
filehandle.write(self.f_b4)
cipher = TwofishECB(stretched_password)
key_k = cipher.decrypt(self.f_b1) + cipher.decrypt(self.f_b2)
key_l = cipher.decrypt(self.f_b3) + cipher.decrypt(self.f_b4)
filehandle.write(self.f_iv)
hmac_checker = HMAC(key_l, "", hashlib.sha256)
cipher = TwofishCBC(key_k, self.f_iv)
end_of_record = self.Field(0xff, 0, "")
for field in self.header.raw_fields.values():
self._write_field_tlv(filehandle, cipher, field)
hmac_checker.update(field.raw_value)
self._write_field_tlv(filehandle, cipher, end_of_record)
hmac_checker.update(end_of_record.raw_value)
for record in self.records:
for field in record.raw_fields.values():
self._write_field_tlv(filehandle, cipher, field)
hmac_checker.update(field.raw_value)
self._write_field_tlv(filehandle, cipher, end_of_record)
hmac_checker.update(end_of_record.raw_value)
self._write_field_tlv(filehandle, cipher, None)
self.f_hmac = hmac_checker.digest()
filehandle.write(self.f_hmac)
filehandle.close()
try:
tmpvault = Vault(password, filename=tmpfilename)
except RuntimeError:
os.remove(tmpfilename)
raise self.VaultFormatError("File integrity check failed")
# after writing the temporary file, replace the original file with it
try:
os.remove(filename)
except OSError:
pass
os.rename(tmpfilename, filename)
def _read_from_file(self, filename, password):
"""
Initialize all class members by loading the contents of a Vault stored in the given file.
"""
assert type(password) != unicode
filehandle = file(filename, 'rb')
# read boilerplate
self.f_tag = filehandle.read(4) # TAG: magic tag
if (self.f_tag != 'PWS3'):
raise self.VaultVersionError("Not a PasswordSafe V3 file")
self.f_salt = filehandle.read(32) # SALT: SHA-256 salt
self.f_iter = struct.unpack(
"<L", filehandle.read(4))[0] # ITER: SHA-256 keystretch iterations
stretched_password = self._stretch_password(
password, self.f_salt, self.f_iter) # P': the stretched key
my_sha_ps = hashlib.sha256(stretched_password).digest()
self.f_sha_ps = filehandle.read(
32) # H(P'): SHA-256 hash of stretched passphrase
if (self.f_sha_ps != my_sha_ps):
raise self.BadPasswordError("Wrong password")
self.f_b1 = filehandle.read(16) # B1
self.f_b2 = filehandle.read(16) # B2
self.f_b3 = filehandle.read(16) # B3
self.f_b4 = filehandle.read(16) # B4
cipher = TwofishECB(stretched_password)
key_k = cipher.decrypt(self.f_b1) + cipher.decrypt(self.f_b2)
key_l = cipher.decrypt(self.f_b3) + cipher.decrypt(self.f_b4)
self.f_iv = filehandle.read(
16) # IV: initialization vector of Twofish CBC
hmac_checker = HMAC(key_l, "", hashlib.sha256)
cipher = TwofishCBC(key_k, self.f_iv)
# read header
while (True):
field = self._read_field_tlv(filehandle, cipher)
if not field:
break
if field.raw_type == 0xff:
break
self.header.add_raw_field(field)
hmac_checker.update(field.raw_value)
# read fields
current_record = self.Record()
while (True):
field = self._read_field_tlv(filehandle, cipher)
if not field:
break
if field.raw_type == 0xff:
self.records.append(current_record)
current_record = self.Record()
else:
hmac_checker.update(field.raw_value)
current_record.add_raw_field(field)
# read HMAC
self.f_hmac = filehandle.read(
32) # HMAC: used to verify Vault's integrity
my_hmac = hmac_checker.digest()
if (self.f_hmac != my_hmac):
raise self.VaultFormatError("File integrity check failed")
self.records.sort()
filehandle.close()
def write_to_file(self, filename, password):
"""
Store contents of this Vault into a file.
"""
assert type(password) != unicode
_last_save = struct.pack("<L", int(time.time()))
self.header.raw_fields[0x04] = self.Field(0x04, len(_last_save), _last_save)
_what_saved = "Loxodo 0.0-git".encode("utf_8", "replace")
self.header.raw_fields[0x06] = self.Field(0x06, len(_what_saved), _what_saved)
# write to temporary file first
(osfilehandle, tmpfilename) = tempfile.mkstemp(
".part", os.path.basename(filename) + ".", os.path.dirname(filename), text=False
)
filehandle = os.fdopen(osfilehandle, "wb")
# FIXME: choose new SALT, B1-B4, IV values on each file write? Conflicting Specs!
# write boilerplate
filehandle.write(self.f_tag)
filehandle.write(self.f_salt)
filehandle.write(struct.pack("<L", self.f_iter))
stretched_password = self._stretch_password(password, self.f_salt, self.f_iter)
self.f_sha_ps = hashlib.sha256(stretched_password).digest()
filehandle.write(self.f_sha_ps)
filehandle.write(self.f_b1)
filehandle.write(self.f_b2)
filehandle.write(self.f_b3)
filehandle.write(self.f_b4)
cipher = TwofishECB(stretched_password)
key_k = cipher.decrypt(self.f_b1) + cipher.decrypt(self.f_b2)
key_l = cipher.decrypt(self.f_b3) + cipher.decrypt(self.f_b4)
filehandle.write(self.f_iv)
hmac_checker = HMAC(key_l, "", hashlib.sha256)
cipher = TwofishCBC(key_k, self.f_iv)
end_of_record = self.Field(0xFF, 0, "")
for field in self.header.raw_fields.values():
self._write_field_tlv(filehandle, cipher, field)
hmac_checker.update(field.raw_value)
self._write_field_tlv(filehandle, cipher, end_of_record)
hmac_checker.update(end_of_record.raw_value)
for record in self.records:
for field in record.raw_fields.values():
self._write_field_tlv(filehandle, cipher, field)
hmac_checker.update(field.raw_value)
self._write_field_tlv(filehandle, cipher, end_of_record)
hmac_checker.update(end_of_record.raw_value)
self._write_field_tlv(filehandle, cipher, None)
self.f_hmac = hmac_checker.digest()
filehandle.write(self.f_hmac)
filehandle.close()
try:
tmpvault = Vault(password, filename=tmpfilename)
except RuntimeError:
os.remove(tmpfilename)
raise self.VaultFormatError("File integrity check failed")
# after writing the temporary file, replace the original file with it
try:
os.remove(filename)
except OSError:
pass
os.rename(tmpfilename, filename)
def get_credential(secret_key, sign_string, algorithm_name):
algorithm = getattr(hashlib, algorithm_name.lower())
hm = HMAC(secret_key.encode(), sign_string.encode(), algorithm)
return b64encode(hm.digest())
