def new(password, server=defaultServer, clientId=None, username="******"):
"""
Encrypts a new @password by interacting with the Pythia service.
@clientId: If specified, this value is used. If omitted, a suitable
value is selected.
@returns a tuple of required values to verify the password: (w,t,z,p)
where:
@w: client ID (key selector)
@t: tweak (randomly generated user ID)
@z: protected passwords
@p: server public key bound to clientId - used to verify future
proofs from this server.
"""
# Set the client ID
if not clientId:
w = secureRandom()
else:
w = clientId
if ersatzHash == True:
ersatzPw = "ersatz"
ersatzHashGen = ersatzlib.ErsatzHashGenerator(hash.pbkdf2_sha1,\
username, password, \
ersatzPw, rounds=5000)
#create ersatz salt
t = ersatzHashGen._compute_ersatz_salt(password, ersatzPw)
ersatzHashGen.salt = t
a = ersatzHashGen._compute_ersatz_hash(password)
a = passlib.utils.ab64_decode(a)
#create ersatz input
ersatzInput = ersatzHashGen._ersatzfy_input(password)
z, p = query(ersatzInput, w, t, server)
z = vpop.wrap(
pyrelic.vpop.update(vpop.unwrapY(z), long(a.encode('hex'), 16)))
#do the Z^a nonsense, where a is the pbkdf2
else:
t = secureRandom()
hashedPW = pbkdf2_sha1.encrypt(password, salt=t, rounds=5000)
z, p = query(hashedPW, w, t, server)
z = vpop.wrap(
pyrelic.vpop.update(vpop.unwrapY(z),
long(hashedPW.encode('hex'), 16)))
#t = secureRandom()
#z,p = query(password, w, t, server)
return w, t, z, p
def check(password, w, t, z, p, server=defaultServer, username="******"):
"""
Checks an existing @password against the Pythia server using the
values (w,t,z,p).
@returns: True if the password passes authentication; False otherwise.
"""
if ersatzHash:
ersatzHashGen = ersatzlib.ErsatzHashGenerator(hash.pbkdf2_sha1,\
username, password, \
"ersatz", rounds=5000)
ersatzHashGen.salt = t
ersatzInput = ersatzHashGen._ersatzfy_input(password)
#check true password
zPrime1, _ = query(ersatzInput, w, t, previousPubkey=p, server=server)
zPrime2, _ = query(password, w, t, previousPubkey=p, server=server)
#create ersatz salt
a = passlib.utils.ab64_decode(
ersatzHashGen._compute_ersatz_hash(password))
zPrime1 = vpop.wrap(
pyrelic.vpop.update(vpop.unwrapY(zPrime1),
long(a.encode('hex'), 16)))
a = passlib.utils.ab64_decode(
hash.pbkdf2_sha1.encrypt(password, salt=t, rounds=5000))
zPrime2 = vpop.wrap(
pyrelic.vpop.update(vpop.unwrapY(zPrime2),
long(a.encode('hex'), 16)))
if z == zPrime1:
return 1
elif z == zPrime2:
return 2
else:
return 0
#check ersatz password
else:
hashedPW = pbkdf2_sha1.encrypt(password, salt=t, rounds=5000)
zPrime, _ = query(hashedPW, w, t, previousPubkey=p, server=server)
zPrime = vpop.wrap(
pyrelic.vpop.update(vpop.unwrapY(zPrime),
long(hashedPW.encode('hex'), 16)))
#zPrime,_ = query(password, w, t, previousPubkey=p, server=server)
return z == zPrime
def new(password, server=defaultServer, clientId=None, username="******"):
"""
Encrypts a new @password by interacting with the Pythia service.
@clientId: If specified, this value is used. If omitted, a suitable
value is selected.
@returns a tuple of required values to verify the password: (w,t,z,p)
where:
@w: client ID (key selector)
@t: tweak (randomly generated user ID)
@z: protected passwords
@p: server public key bound to clientId - used to verify future
proofs from this server.
"""
# Set the client ID
if not clientId:
w = secureRandom()
else:
w = clientId
if ersatzHash == True:
ersatzPw = "ersatz"
ersatzHashGen = ersatzlib.ErsatzHashGenerator(hash.pbkdf2_sha1,\
username, password, \
ersatzPw, rounds=5000)
#create ersatz salt
t = ersatzHashGen._compute_ersatz_salt(password,ersatzPw)
ersatzHashGen.salt = t
a = ersatzHashGen._compute_ersatz_hash(password)
a = passlib.utils.ab64_decode(a)
#create ersatz input
ersatzInput = ersatzHashGen._ersatzfy_input(password)
z,p = query(ersatzInput, w, t, server)
z = vpop.wrap(pyrelic.vpop.update(vpop.unwrapY(z), long(a.encode('hex'),16)))
#do the Z^a nonsense, where a is the pbkdf2
else:
t = secureRandom()
hashedPW = pbkdf2_sha1.encrypt(password, salt=t, rounds=5000)
z,p = query(hashedPW, w, t, server)
z = vpop.wrap(pyrelic.vpop.update(vpop.unwrapY(z), long(hashedPW.encode('hex'),16)))
#t = secureRandom()
#z,p = query(password, w, t, server)
return w, t, z, p
def update(wPrime,w,t,z,p,server=defaultServer):
# Query the service via HTTP(S) GET
response = fetch(queryUrlUpdateTemplate.format(server,w,wPrime))
# Grab the required fields from the response.
pPrime,delta = extract(response, ["pPrime","delta"])
updatedZ = vpop.wrap(pyrelic.vpop.update(vpop.unwrapY(z), pyrelic.vpop.unwrapDelta(delta)))
updateP = vpop.wrap(vpop.unwrapP(p)*vpop.unwrapLong(delta))
return wPrime, t, updatedZ, updateP
def update(wPrime, w, t, z, p, server=defaultServer):
# Query the service via HTTP(S) GET
response = fetch(queryUrlUpdateTemplate.format(server, w, wPrime))
# Grab the required fields from the response.
pPrime, delta = extract(response, ["pPrime", "delta"])
updatedZ = vpop.wrap(
pyrelic.vpop.update(vpop.unwrapY(z), pyrelic.vpop.unwrapDelta(delta)))
updateP = vpop.wrap(vpop.unwrapP(p) * vpop.unwrapLong(delta))
return wPrime, t, updatedZ, updateP
def check(password, w, t, z, p, server=defaultServer, username="******"):
"""
Checks an existing @password against the Pythia server using the
values (w,t,z,p).
@returns: True if the password passes authentication; False otherwise.
"""
if ersatzHash:
ersatzHashGen = ersatzlib.ErsatzHashGenerator(hash.pbkdf2_sha1,\
username, password, \
"ersatz", rounds=5000)
ersatzHashGen.salt = t
ersatzInput = ersatzHashGen._ersatzfy_input(password)
#check true password
zPrime1,_ = query(ersatzInput, w, t, previousPubkey=p, server=server)
zPrime2,_ = query(password, w, t, previousPubkey=p, server=server)
#create ersatz salt
a = passlib.utils.ab64_decode(ersatzHashGen._compute_ersatz_hash(password))
zPrime1 = vpop.wrap(pyrelic.vpop.update(vpop.unwrapY(zPrime1), long(a.encode('hex'),16)))
a = passlib.utils.ab64_decode(hash.pbkdf2_sha1.encrypt(password, salt=t, rounds=5000))
zPrime2 = vpop.wrap(pyrelic.vpop.update(vpop.unwrapY(zPrime2), long(a.encode('hex'),16)))
if z == zPrime1:
return 1
elif z == zPrime2:
return 2
else:
return 0
#check ersatz password
else:
hashedPW = pbkdf2_sha1.encrypt(password, salt=t, rounds=5000)
zPrime,_ = query(hashedPW, w, t, previousPubkey=p, server=server)
zPrime = vpop.wrap(pyrelic.vpop.update(vpop.unwrapY(zPrime), long(hashedPW.encode('hex'),16)))
#zPrime,_ = query(password, w, t, previousPubkey=p, server=server)
return z == zPrime
def eval(self,w,t,pw):
"""
Runs an eval and returns the result.
"""
# Blind and serialize the pw
r,x = vpop.blind(pw)
x = vpop.wrap(x)
# Call the URL and verify the response
response = self.client.get(VpopAdvTest.urlEval.format(w,t,x))
ySerial = str(self.check(response, "y"))
# Deserialize and de-blind the result.
y = vpop.unwrapY(ySerial)
return vpop.deblind(r,y)
def testProof(self):
"""
Ensures the proof is valid.
"""
# Make an eval request
r,x = vpop.blind(pw)
xWrap = vpop.wrap(x)
url = VpopEvalTest.urlTemplate.format(w,t,xWrap)
r = self.parseResponse(self.client.get(url))
# Deserialize the items needed to verify the proof.
y = vpop.unwrapY(r["y"])
pi = (vpop.unwrapP(r["p"]), vpop.unwrapC(r["c"]), vpop.unwrapU(r["u"]) )
# Test the proof
self.assertTrue( vpop.verify(x, t, y, pi) )
def query(password, w, t, server=defaultServer, previousPubkey=None):
"""
Queries the a Pythia PRF service and verifies the server's ZKP.
@returns (z,p) where: @z is the encrypted password and @p is the
server's pubkey bound to clientId
Raises an exception if there are any problems interacting with the service
or if the server's ZKP fails verification.
"""
# Blind the password
r, x = vpop.blind(password)
xSerialized = vpop.wrap(x)
# Query the service via HTTP(S) GET
response = fetch(queryUrlTemplate.format(server, w, t, xSerialized))
# Grab the required fields from the response.
p, y, c, u = extract(response, ["p", "y", "c", "u"])
# Check the pubkey
if previousPubkey and previousPubkey != p:
print "previous: " + previousPubkey
print "p: " + p
raise Exception(
"Server-provided pubkey doesn't match previous pubkey.")
# Deserialize the response fields
p, y, c, u = (vpop.unwrapP(p), vpop.unwrapY(y), vpop.unwrapC(c),
vpop.unwrapU(u))
pi = (p, c, u)
# Verify the result by checking the proof
vpop.verify(x, t, y, pi)
# Deblind the result
z = vpop.deblind(r, y)
# Return the important fields in serialied form
z, p = vpop.wrap(z), vpop.wrap(p)
return z, p
def query(password, w, t, server=defaultServer, previousPubkey=None):
"""
Queries the a Pythia PRF service and verifies the server's ZKP.
@returns (z,p) where: @z is the encrypted password and @p is the
server's pubkey bound to clientId
Raises an exception if there are any problems interacting with the service
or if the server's ZKP fails verification.
"""
# Blind the password
r,x = vpop.blind(password)
xSerialized = vpop.wrap(x)
# Query the service via HTTP(S) GET
response = fetch(queryUrlTemplate.format(server,w,t,xSerialized))
# Grab the required fields from the response.
p,y,c,u = extract(response, ["p","y","c","u"])
# Check the pubkey
if previousPubkey and previousPubkey != p:
print "previous: " + previousPubkey
print "p: "+ p
raise Exception("Server-provided pubkey doesn't match previous pubkey.")
# Deserialize the response fields
p,y,c,u = (vpop.unwrapP(p), vpop.unwrapY(y),
vpop.unwrapC(c), vpop.unwrapU(u))
pi = (p,c,u)
# Verify the result by checking the proof
vpop.verify(x, t, y, pi)
# Deblind the result
z = vpop.deblind(r,y)
# Return the important fields in serialied form
z,p = vpop.wrap(z), vpop.wrap(p)
return z,p