Crypto 3

from Crypto.Hash import SHA256

Chunk = []
with open( 'file','rb' ) as f:
    while True:
        s = f.read( 1024 )
        Chunk.append( s )
        if len( s ) < 1024 :
            print( len(s) )
            break

Chunk.reverse()
h = SHA256.new( Chunk[0] )
for i in range( 1,len( Chunk ) ):
    b = Chunk[i] + bytes.fromhex( h.hexdigest() )
    h = SHA256.new( b )

print( h.hexdigest() )