密码学:基于python支持448位输入的sha-1算法

#只支持448比特

#寄存器的初始值
H0 = 0x67452301
H1 = 0xefcdab89
H2 = 0x98badcfe
H3 = 0x10325476
H4 = 0xc3d2e1f0

#分组的所有字
W=[]

#常数值Kt
def K(t):
    if 0 <= t and t<=19:
        return 0x5a827999
    elif 20 <= t and t<=39:
        return 0x6ed9eba1
    elif 40 <= t and t<=59:
        return 0x8f1bbcdc
    elif 60 <= t and t<=79:
        return 0xca62c1d6
   
#f基本逻辑函数
def F(t,b,c,d):
    if 0 <= t and t<=19:
        return (b&c) | (~b&d)
    elif 20 <= t and t<=39:
        return b^c^d
    elif 40 <= t and t<=59:
        return (b&c) | (b&d) | (c&d)
    elif 60 <= t and t<=79:
        return b^c^d

#比特字Wt的值
def Wt(t):
    a = W[t-16]^W[t-14]^W[t-8]^W[t-3]
    W[t] = S(1,a)
    return W[t]

 

#循环左移k
def S(k,a):
    return ((a>>32-k) | (a<<k) & Sum())

#求32位1
def Sum():
    s = 0;
    for i in range(32):
        s = s + 2**i
    return s

#分割M
def dM(m):
    for i in range(16):
        W[i] = (m>>32*(15-i)) & Sum()
   

 

if __name__ == “__main__”:
    A = H0
    B = H1
    C = H2
    D = H3
    E = H4

    i=0
    m = 0
    M = input()
    L = 8*len(M)
    for ch in M:
        m = m*(2**8)+ord(ch)

    if L < 448:
        m = m*2+1
        #添加填充位
        m = m*2**(447 – L)
        #添加长度
        m = m*2**64 + L

    for i in range(80):
        W.append(i)

    dM(m)
    for i in range(16,80):
        Wt(i)

    print(hex(m))

 #80步循环的寄存器
    for t in range(80):
        temp = (S(5,A)%(2**32)+W[t]%(2**32)+E+F(t,B,C,D)+K(t)%(2**32))%2**32
        E = D
        D = C
        C = S(30,B)
        B = A
        A = temp
        print(t,’:  ‘,hex(A),’  ‘,hex(B),”   “,hex(C),”   “,hex(D),”   “,hex(E))

    A = (A + H0)%2**32
    B = (B + H1)%2**32
    C = (C + H2)%2**32
    D = (D + H3)%2**32
    E = (E + H4)%2**32

    isha = A*2**(4*32) + B*2**(3*32) + C*2**(2*32) + D*2**32 + E
    sha = hex(isha)
    print(“消息摘要:”,str(sha)[2:])
   
       
       

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