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Idempotent hashing tool for convenience

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Elliot Nunn 2020-12-01 10:39:40 +08:00
parent d2181a6ae8
commit a8e0e54c58
1 changed files with 15 additions and 11 deletions
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26
snefru_hash.py
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@ -353,22 +353,26 @@ def snefru(inbytes):
return struct.pack('>4L', *_Hash512(temp_output, p0, p1, p2))
def append_snefru(x):
if len(x) % 512 == 0:
maybe_already = snefru(x[:-64])
if x[-16:] == maybe_already: return x
while len(x) % 512 != 512 - 64: x += b'\0'
the_hash = snefru(x)
while len(x) % 512 != 512 - 16: x += b'\0'
x += the_hash
return x
if __name__ == '__main__':
import sys
for p in sys.argv[1:]:
try:
x = open(p, 'rb').read()
if len(x) % 512 == 0:
maybe_already = snefru(x[:-64])
if x[-16:] == maybe_already: continue
while len(x) % 512 != 512 - 64: x += b'\0'
the_hash = snefru(x)
while len(x) % 512 != 512 - 16: x += b'\0'
x += the_hash
open(p, 'wb').write(x)
y = append_snefru(x)
if x != y: open(p, 'wb').write(x)
except Exception as e:
print(e)