def iterblocks(self,M,bitlen=None):
# pad M into M' (see spec, p.12-13)
if bitlen is None:
bitlen=len(M)*8
else:
M = hex(Bits(M,bitlen)//Bits(1,1))
# get BitPad flag:
B = 1 if bitlen%8 else 0
# pad M' into M'':
l = len(M)
lb = len(self.G)
nb,rb = divmod(l,lb)
lp=0
if l==0 or rb>0:
lp = lb-rb
M += '\0'*lp
nb += 1
# init generator:
P = StringIO.StringIO(M)
Ts = self.Ts
Ts.First = 1
for b in range(nb-1):
m = P.read(lb)
Ts.Position += lb
yield (pack(Ts),m)
Ts.First=0
# last M'' block:
Ts.Final = 1
Ts.BitPad = B
m = P.read(lb)
Ts.Position += lb-lp
yield (pack(Ts),m)
def output(self,G):
lq,lr = divmod(self.No,8)
if lr!=0: lq += 1
O = []
n = l = 0
T = Tweak(Type='out')
ubi = UBI(Threefish,G,T)
while l<lq:
o = ubi(pack(Bits(n,64)))
l += len(o)
O.append(o)
n += 1
if l>lq: O[-1]=O[-1][:(lq-l)]
return ''.join(O)
def __init__(self,Nb,No,
schema="SHA3",version=1,Yl=0,Yf=0,Ym=0,
key=None,
prs=None,
PK=None,
kdf=None,
nonce=None):
# block length and output length:
assert Nb in (256,512,1024)
self.Nb = Nb/8
self.No = No
# Config string (256 bits)
self.C = schema+pack(Bits(version,16)//Bits(0,16)//Bits(No,64))
self.Yl = Yl
self.Yf = Yf
self.Ym = Ym
self.C += chr(Yl)+chr(Yf)+chr(Ym)+'\0'*13
self.key = key
self.prs = prs
self.PK = PK
self.kdf = kdf
self.non = nonce