其他 - 在Python中实现MD5

我在Wikipedia上关注有关MD5实施的页面。伪代码直接嵌入到链接中。

但是，当我将伪代码转换为python时，它给出了一个非常奇怪的输出，与演示中显示的输出没有任何相似之处。

md5.py

import math


def leftrotate(x, c):
    return (x << c) or (x >> (32 - c))


# All variables are unsigned 32 bit and wrap modulo 2^32 when calculating
s = [None] * 64
K = [None] * 64

# s specifies the per-round shift amounts
s[0:16] = [7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22]
s[16:32] = [5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20]
s[32:48] = [4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23]
s[48:64] = [6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21]

# Use binary integer part of the sines of integers (Radians) as constants:
K = [math.floor(math.pow(2, 32) * math.fabs(math.sin(i + 1))) for i in range(64)]

# Initialize variables
a0 = 0x67452301
b0 = 0xefcdab89
c0 = 0x98badcfe
d0 = 0x10325476

msg0 = "The quick brown fox jumps over the lazy dog"
# Converting String to binary
msg = ''.join(format(ord(i), 'b') for i in msg0)

# Pre-processing: adding a single bit
#   The input bytes are considered as bits strings,
#   where the first bit is the most significant bit of the byte
message = list(msg)
message.append("1")

# Pre-processing: padding with zeros
for i in range(447 - len(msg)):
    message.append("0")
for i in range(64):
    message.append("64")

msg = "".join(message)

M = []
for i in range(0, 512, 32):
    M.append("".join(message[i:i + 32]))
# Initialize hash value for this chunk
A = a0
B = b0
C = c0
D = d0

for i in range(64):
    F = 0
    g = 0
    if 0 <= i <= 15:
        F = D ^ (B and (C ^ D))
        g = i
    elif 16 <= i <= 31:
        F = C ^ (D and (B ^ C))
        g = (5 * i + 1) % 16
    elif 32 <= i <= 47:
        F = B ^ C ^ D
        g = (3 * i + 5) % 16
    elif 48 <= i <= 63:
        F = C ^ (B or (not D))
        g = (7 * i) % 16
    # Be wary of the below definitions of a, b, c, d
    F = F + A + K[i] + int(M[g])
    A = D
    D = C
    C = B
    B = B + leftrotate(F, s[i])

a0 += A
b0 += B
c0 += C
d0 += D

print(a0 + b0 + c0 + d0)

输出

(input = msg0 = "The quick brown fox jumps over the lazy dog")
64753135551430969455044517516606091785810184138594829859667366632969211689605539951611300227364936455768076694404884226395355419
03996976374438250472707827439981815374596773986313857734975864212023704601385676211761628136173288119161166663698645808505752643
4

详细地，请有人向我解释这一行：

将块分成16个32位字M[j]，0≤j≤15

在这一点上，我感到非常困惑，因为我认为message应该以字符串形式输入，但是将其转换为二进制不起作用。我认为在页面上，短语bit表示二进制，还是我错了？

任何帮助表示赞赏。