ieee754 + rsa implementierung in python
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54
ieee754.py
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54
ieee754.py
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def bin2hex(s):
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ht = [ str(i) for i in range(10) ] + [ "A","B","C","D","E","F" ]
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h = ""
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while s != "":
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h = ht[int(s[-4:],2)] + h
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s = s[:-4]
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return "0x"+h
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def to_mantisse(d,n=23):
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s = ""
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for i in range(n):
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d *= 2
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s += str(int(d)%2)
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return s
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def to_binary(d,n=8):
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s = ""
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for i in range(n):
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s = str(d & 1) + s
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d = d >> 1
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return s
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def to_ieee754(d,el,ml):
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if d < 0:
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s = 1
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d *= -1
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else:
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s = 0
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g = 0
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while d >= 2:
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d /= 2
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g += 1
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while d <= 0.5:
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d *= 2
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g -= 1
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bias = 2**(el-1)-1
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e = g+bias
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return str(s)+to_binary(e,n=el)+to_mantisse(d,n=ml)
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def to_ieee754_single(d):
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return to_ieee754(d,el=8,ml=23)
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def to_ieee754_double(d):
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return to_ieee754(d,el=11,ml=52)
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def to_ieee754_single_hex(d):
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return bin2hex(to_ieee754_single(d))
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def to_ieee754_double_hex(d):
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return bin2hex(to_ieee754_double(d))
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if __name__ == "__main__":
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print(bin2hex(to_ieee754_double(-2.5)))
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print(bin2hex(to_ieee754_double(-1.75)))
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