2010-06-22 58 views
-2

我知道ive之前曾问过类似的问题,但是:这个伪代码here与我的代码相同吗?大写变量是伪代码中带有“'”的变量,条件值全部在列表中,例如:所有“s”条件都在列表“s”和“s”中,列表“S”中的条件为这两个代码是否相等?

for i in xrange(t): 
    a = h0; b = h1; c = h2; d = h3; e = h4 
    A = h0; B = h1; C = h2; D = h3; E = h4 
    X = data[512*i:512*(i+1)]     # the data is a binary string 
    X = [int(X[32*x:32*(x+1)],2) for x in xrange(16)] 
    for j in xrange(80): 
     a, e, d, c, b = e, d, ROL(c,10), b, ROL((a + F(b, c, d, j) + X[r[j]] + k[j/16])%(1<<32), s[j]) + e 
     A, E, D, C, B = E, D, ROL(C,10), B, ROL((A + F(B, C, D, 79-j) + X[R[j]] + K[j/16])%(1<<32), S[j]) + E 
    T = (h1+c+D)%(1<<32) 
    h1 = (h2+d+E)%(1<<32) 
    h2 = (h3+e+A)%(1<<32) 
    h3 = (h4+a+B)%(1<<32) 
    h4 = (h0+b+C)%(1<<32) 
    h0 = T 

我一直在研究这段代码(偶尔),现在已经有相当长一段时间了,而且由于某些原因,我还没有能够使这段代码正常工作。为什么???确保数据的预处理是正确的,但即使我复制其他人的代码并将它们转换成python时,输出也没有接近正确的地方

这部分代码应该是正确的:

def F(x,y,z,round): 
    if round<16: 
     return x^y^z 
    elif 16<=round<32: 
     return (x & y) | (~x & z) 
    elif 32<=round<48: 
     return (x | ~y)^z 
    elif 48<=round<64: 
     return (x & z) | (y & ~z) 
    elif 64<=round: 
     return x^(y | ~z) 

h0 = 0x67452301; h1 = 0xEFCDAB89; h2 = 0x98BADCFE; h3 = 0x10325476; h4 = 0xC3D2E1F0 
k = [0, 0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xA953FD4E] 
K = [0x50A28BE6, 0x5C4DD124, 0x6D703EF3, 0x7A6D76E9, 0] 

s =  [ 11,14,15,12,5,8,7,9,11,13,14,15,6,7,9,8, 
     7,6,8,13,11,9,7,15,7,12,15,9,11,7,13,12, 
     11,13,6,7,14,9,13,15,14,8,13,6,5,12,7,5, 
     11,12,14,15,14,15,9,8,9,14,5,6,8,6,5,12, 
     9,15,5,11,6,8,13,12,5,12,13,14,11,8,5,6] 

S =  [ 8,9,9,11,13,15,15,5,7,7,8,11,14,14,12,6, 
     9,13,15,7,12,8,9,11,7,7,12,7,6,15,13,11, 
     9,7,15,11,8,6,6,14,12,13,5,14,13,13,7,5, 
     15,5,8,11,14,14,6,14,6,9,12,9,12,5,15,8, 
     8,5,12,9,12,5,14,6,8,13,6,5,15,13,11,11] 

r =  range(16) + [ 
     7, 4, 13, 1, 10, 6, 15, 3, 12, 0, 9, 5, 2, 14, 11, 8, 
     3, 10, 14, 4, 9, 15, 8, 1, 2, 7, 0, 6, 13, 11, 5, 12, 
     1, 9, 11, 10, 0, 8, 12, 4, 13, 3, 7, 15, 14, 5, 6, 2, 
     4, 0, 5, 9, 7, 12, 2, 10, 14, 1, 3, 8, 11, 6, 15, 13] 

R =  [ 5, 14, 7, 0, 9, 2, 11, 4, 13, 6, 15, 8, 1, 10, 3, 12, 
     6, 11, 3, 7, 0, 13, 5, 10, 14, 15, 8, 12, 4, 9, 1, 2, 
     15, 5, 1, 3, 7, 14, 6, 9, 11, 8, 12, 2, 10, 0, 4, 13, 
     8, 6, 4, 1, 3, 11, 15, 0, 5, 12, 2, 13, 9, 7, 10, 14, 
     12, 15, 10, 4, 1, 5, 8, 7, 6, 2, 13, 14, 0, 3, 9, 11] 

回答

3

您指向的伪代码定义了一个函数f,常量K和K',选择器r和r'等等 - 这些东西都隐藏在您要显示的代码中?你似乎在使用它们,但是,我们(和你)怎么知道它们是正确的,没有任何检查?

您的错误,毕竟,可能在你隐藏的所有这些代码。

+0

好的。我添加了常量和f。我很确定他们是正确的,虽然 – calccrypto 2010-06-23 01:00:53

+0

“很肯定”和“肯定/证明” – 2010-06-23 01:23:49

+0

之间有很大的区别,他们是一样的吗? – calccrypto 2010-06-23 01:39:57

0

我的建议是将代码放入函数并进行单元测试。你有一个预期的输出,而单元测试是一种非常有用的方式,可以验证代码是否符合它的要求。例如,你的列表理解结果是否在正确的列表中?

我还建议你阅读Style Guide for Python,因为你的代码比它需要的更复杂。例如,您在一行中有多个语句。