Python client limited to k<=32

[tkaitchuck]

Attempting k=128 results in:
File "../tests/rappor_sim.py", line 238, in
main(sys.argv)
File "../tests/rappor_sim.py", line 231, in main
params1, params2, irr_rand, opts.assoc_testdata, csv_in, csv_out)
File "../tests/rappor_sim.py", line 121, in GenAssocTestdata
irr1 = string_encoder.encode(v1)
File "/usr/local/google/home/tkaitchuck/rappor2/rappor/client/python/rappor.py", line 335, in encode
_, _, irr = self._internal_encode(word)
File "/usr/local/google/home/tkaitchuck/rappor2/rappor/client/python/rappor.py", line 311, in _internal_encode
prr, irr = self._internal_encode_bits(bloom)
File "/usr/local/google/home/tkaitchuck/rappor2/rappor/client/python/rappor.py", line 261, in _internal_encode_bits
self.secret, to_big_endian(bits), self.params.prob_f,
File "/usr/local/google/home/tkaitchuck/rappor2/rappor/client/python/rappor.py", line 162, in to_big_endian
return struct.pack('>L', i)

trying with k=64 results in:
Traceback (most recent call last):
File "../tests/rappor_sim.py", line 238, in
main(sys.argv)
File "../tests/rappor_sim.py", line 231, in main
params1, params2, irr_rand, opts.assoc_testdata, csv_in, csv_out)
File "../tests/rappor_sim.py", line 121, in GenAssocTestdata
irr1 = string_encoder.encode(v1)
File "/usr/local/google/home/tkaitchuck/rappor2/rappor/client/python/rappor.py", line 335, in encode
_, _, irr = self._internal_encode(word)
File "/usr/local/google/home/tkaitchuck/rappor2/rappor/client/python/rappor.py", line 311, in _internal_encode
prr, irr = self._internal_encode_bits(bloom)
File "/usr/local/google/home/tkaitchuck/rappor2/rappor/client/python/rappor.py", line 262, in _internal_encode_bits
self.params.num_bloombits)
File "/usr/local/google/home/tkaitchuck/rappor2/rappor/client/python/rappor.py", line 201, in get_prr_masks
raise RuntimeError('%d bits is more than the max of %d', num_bits, len(d))
NameError: global name 'd' is not defined

[andychu]

There are two limitations on k in Python:

1. fastrand module supporting 64 bits
2. PRR RNG is initialized with 32 bit value