90 lines
3.0 KiB
Python
90 lines
3.0 KiB
Python
"""Class for storing SRP password verifiers."""
|
|
|
|
from utils.cryptomath import *
|
|
from utils.compat import *
|
|
import mathtls
|
|
from BaseDB import BaseDB
|
|
|
|
class VerifierDB(BaseDB):
|
|
"""This class represent an in-memory or on-disk database of SRP
|
|
password verifiers.
|
|
|
|
A VerifierDB can be passed to a server handshake to authenticate
|
|
a client based on one of the verifiers.
|
|
|
|
This class is thread-safe.
|
|
"""
|
|
def __init__(self, filename=None):
|
|
"""Create a new VerifierDB instance.
|
|
|
|
@type filename: str
|
|
@param filename: Filename for an on-disk database, or None for
|
|
an in-memory database. If the filename already exists, follow
|
|
this with a call to open(). To create a new on-disk database,
|
|
follow this with a call to create().
|
|
"""
|
|
BaseDB.__init__(self, filename, "verifier")
|
|
|
|
def _getItem(self, username, valueStr):
|
|
(N, g, salt, verifier) = valueStr.split(" ")
|
|
N = base64ToNumber(N)
|
|
g = base64ToNumber(g)
|
|
salt = base64ToString(salt)
|
|
verifier = base64ToNumber(verifier)
|
|
return (N, g, salt, verifier)
|
|
|
|
def __setitem__(self, username, verifierEntry):
|
|
"""Add a verifier entry to the database.
|
|
|
|
@type username: str
|
|
@param username: The username to associate the verifier with.
|
|
Must be less than 256 characters in length. Must not already
|
|
be in the database.
|
|
|
|
@type verifierEntry: tuple
|
|
@param verifierEntry: The verifier entry to add. Use
|
|
L{tlslite.VerifierDB.VerifierDB.makeVerifier} to create a
|
|
verifier entry.
|
|
"""
|
|
BaseDB.__setitem__(self, username, verifierEntry)
|
|
|
|
|
|
def _setItem(self, username, value):
|
|
if len(username)>=256:
|
|
raise ValueError("username too long")
|
|
N, g, salt, verifier = value
|
|
N = numberToBase64(N)
|
|
g = numberToBase64(g)
|
|
salt = stringToBase64(salt)
|
|
verifier = numberToBase64(verifier)
|
|
valueStr = " ".join( (N, g, salt, verifier) )
|
|
return valueStr
|
|
|
|
def _checkItem(self, value, username, param):
|
|
(N, g, salt, verifier) = value
|
|
x = mathtls.makeX(salt, username, param)
|
|
v = powMod(g, x, N)
|
|
return (verifier == v)
|
|
|
|
|
|
def makeVerifier(username, password, bits):
|
|
"""Create a verifier entry which can be stored in a VerifierDB.
|
|
|
|
@type username: str
|
|
@param username: The username for this verifier. Must be less
|
|
than 256 characters in length.
|
|
|
|
@type password: str
|
|
@param password: The password for this verifier.
|
|
|
|
@type bits: int
|
|
@param bits: This values specifies which SRP group parameters
|
|
to use. It must be one of (1024, 1536, 2048, 3072, 4096, 6144,
|
|
8192). Larger values are more secure but slower. 2048 is a
|
|
good compromise between safety and speed.
|
|
|
|
@rtype: tuple
|
|
@return: A tuple which may be stored in a VerifierDB.
|
|
"""
|
|
return mathtls.makeVerifier(username, password, bits)
|
|
makeVerifier = staticmethod(makeVerifier) |