Jayden/hdcp-genkey
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convert map/filter use to generator expressions

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Apparently using generator expressions and list comprehensions is more
'pythonic'. Who am I to disagree? :)
This commit is contained in:
Rich Wareham
2010-09-21 14:18:47 +01:00
parent 0f461710d8
commit cdaa1db667
1 changed files with 8 additions and 8 deletions
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16
generate_key.py
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@@ -112,11 +112,11 @@ def do_test(key_matrix):
# add sink keys together according to src ksv # add sink keys together according to src ksv
key1 = reduce(lambda x, y: (x+y) & 0xffffffffffffff, key1 = reduce(lambda x, y: (x+y) & 0xffffffffffffff,
map(lambda x: x[1], filter(lambda x: src_ksv & (1<<x[0]), zip(range(40), snk_key)))) ( x[1] for x in zip(range(40), snk_key) if src_ksv & (1<<x[0]) ))
# add source keys together according to sink ksv # add source keys together according to sink ksv
key2 = reduce(lambda x, y: (x+y) & 0xffffffffffffff, key2 = reduce(lambda x, y: (x+y) & 0xffffffffffffff,
map(lambda x: x[1], filter(lambda x: snk_ksv & (1<<x[0]), zip(range(40), src_key)))) ( x[1] for x in zip(range(40), src_key) if snk_ksv & (1<<x[0]) ))
print('\nGenerated keys: sink = %014x, source = %014x' % (key1, key2)) print('\nGenerated keys: sink = %014x, source = %014x' % (key1, key2))
@@ -187,21 +187,21 @@ def gen_source_key(ksv, key_matrix):
the source private key.""" the source private key."""
# generate a list of bits for the KSV starting with the LSB # generate a list of bits for the KSV starting with the LSB
ksv_bits = map(lambda x: (ksv >> x) & 1, range(40)) ksv_bits = ( (ksv >> x) & 1 for x in range(40) )
# zip the master key matrix and the ksv s.t. the LSB of KSV is associated with # zip the master key matrix and the ksv s.t. the LSB of KSV is associated with
# the first row, etc. Then filter to only select those rows where the # the first row, etc. Then filter to only select those rows where the
# appropriate bit of the KSV is 1. # appropriate bit of the KSV is 1.
master_rows = map(lambda x: x[1], filter(lambda x: x[0] == 1, zip(ksv_bits, key_matrix))) master_rows = ( x[1] for x in zip(ksv_bits, key_matrix) if x[0] == 1 )
# now generate the key # now generate the key
key = [0] * 40 key = [0] * 40
for row in master_rows: for row in master_rows:
# add row to key # add row to key
key = map(lambda x: (x[0] + x[1]) & 0xffffffffffffff, zip(key, row)) key = [ (x[0] + x[1]) & 0xffffffffffffff for x in zip(key, row) ]
return key return tuple(key)
def gen_sink_key(ksv, key_matrix): def gen_sink_key(ksv, key_matrix):
"""Generate a sink key from the master key matrix passed. """Generate a sink key from the master key matrix passed.
@@ -220,7 +220,7 @@ def output_human_readable(ksv, key, is_sink):
print('KSV: %010x' % ksv) print('KSV: %010x' % ksv)
# output the key # output the key
key_strs = map(lambda x: '%014x' % x, key) key_strs = [ '%014x' % x for x in key ]
print('\n%s Key:' % ('Sink' if is_sink else 'Source')) print('\n%s Key:' % ('Sink' if is_sink else 'Source'))
for idx in range(0, 40, 5): for idx in range(0, 40, 5):
@@ -233,7 +233,7 @@ def output_json(ksv, key, is_sink):
print(json.dumps( { print(json.dumps( {
'ksv': ('%010x' % ksv), 'ksv': ('%010x' % ksv),
'key': map(lambda x: '%014x' % x, key), 'key': [ '%014x' % x for x in key ],
'type': 'sink' if is_sink else 'source' }, 'type': 'sink' if is_sink else 'source' },
sort_keys=True, indent=True)) sort_keys=True, indent=True))