为什么我的哈希函数不输出动态值？
Why doesn't my hash function output a dynamic value?
我是这个领域的新手，正在尝试学习一些有关如何编写加密哈希函数的知识。
为了动手实践，我尝试为 Python 3.6 及更高版本更新 PySHA2 算法（原始版本不适用于 Python 2.5+ 和作者说他不会解决这个问题）。我不打算将此算法用于任何工作，只是为了知识而编写代码。
我已经走到这一步了：
import copy
import struct
_initial_hashes = [0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
0x510e527fade682d1, 0x9b05688c2b3e6c1f, 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179]
_round_constants = [0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118,
0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30,
0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3,
0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817]
def _rit_rot(on: int, by: int) -> int:
"""
helper function for right rotation as it isn't done by a simple bitwise operation (xor is done by '^')
:param on: value to be rotated
:param by: value by which to rotate
:return: right rotated 'on'
"""
return ((on >> by) | (on << (64 - by))) & 0xFFFFFFFFFFFFFFFF
def hash_main(chunk):
global _initial_hashes, _round_constants
# start the hashing process
# to begin, create a place to store the 80 words that we'll make
words = [0] * 80
# first 16 words will be saved without any changes
words[:16] = struct.unpack('!16Q', chunk)
# extend these 16 words into the remaining 64 words of 'message schedule array'
for i in range(16, 80):
part_1 = _rit_rot(words[i - 15], 1) ^ _rit_rot(words[i - 15], 8) ^ (words[i - 15] >> 7)
part_2 = _rit_rot(words[i - 2], 19) ^ _rit_rot(words[i - 2], 61) ^ (words[i - 2] >> 6)
words[i] = (words[i - 16] + part_1 + words[i - 7] + part_2) & 0xFFFFFFFFFFFFFFFF
# create the working variables
a, b, c, d, e, f, g, h = _initial_hashes
# start the compression function
for z in range(80):
var_1 = _rit_rot(a, 28) ^ _rit_rot(a, 34) ^ _rit_rot(a, 39)
var_2 = _rit_rot(e, 14) ^ _rit_rot(e, 18) ^ _rit_rot(e, 41)
var_3 = (a & b) ^ (a & c) ^ (b & c)
var_4 = (e & f) ^ ((~e) & g)
temp_1 = var_1 + var_3
temp_2 = h + var_2 + var_4 + _round_constants[z] + words[z]
# remix the hashes
h = g
g = f
f = e
e = (d + temp_2) & 0xFFFFFFFFFFFFFFFF
d = c
c = b
b = a
a = (temp_1 + temp_2) & 0xFFFFFFFFFFFFFFFF
# add this chunk to initial hashes
_initial_hashes = [(x + y) & 0xFFFFFFFFFFFFFFFF for x, y in zip(_initial_hashes,
[a, b, c, d, e, f, g, h])]
def _sha_backend_update(text_copy, _buffer, _counter):
"""
backend function that hashes given string
"""
global _initial_hashes, _round_constants
# create variables for cycling
_buffer += text_copy
_counter += len(text_copy)
# assert the variables are correct
if not text_copy:
return
if type(text_copy) is not str:
raise TypeError("Invalid Object! Please enter a valid string for hashing!")
# break the buffer into 128-bit chunks
while len(_buffer) >= 128:
chunk = _buffer[:128].encode()[1:]
hash_main(chunk)
_buffer = _buffer[128:]
def sha_backend_digest(text_to_hash: str, _buffer: str, _counter: int,
_output_size: int, hex_output: bool = False):
# initialize variables
variable_x = _counter & 0x7F
length = str(struct.pack('!Q', _counter << 3))
# set the thresholds
if variable_x < 112:
padding_len = 111 - variable_x
else:
padding_len = 239 - variable_x
# make a copy of the text_to_hash before starting hashing
text_copy = copy.deepcopy(text_to_hash)
m = '\x80' + ('\x00' * (padding_len + 8)) + length
# run the update function
_sha_backend_update(text_copy, _buffer, _counter)
# return the hash value
return_val = [hex(stuff) for stuff in _initial_hashes[:_output_size]]
if hex_output is True:
return_val = [int(stuff, base=16) for stuff in return_val]
return return_val
return ''.join(return_val)
def sha_512(text_to_hash: str, hex_digest: bool = False) -> str:
"""
frontend function for SHA512 hashing
:return: hashed string
"""
# before anything, check if the input is correct
if not text_to_hash:
return ""
if type(text_to_hash) is not str:
raise TypeError("Invalid content! Please provide content in correct format for hashing!")
# initialize default variables
_buffer = ''
_counter = 0
_output_size = 8
# start the backend function
return sha_backend_digest(text_to_hash, _buffer, _counter, _output_size, hex_output=hex_digest)
message = "This is a string to be hashed"
from hashlib import sha512
print("hashlib gives: ", sha512(message.encode()).hexdigest())
print("I give: ", sha_512(message))
很明显，我不理解这个算法中的很多东西，并且从字面上复制了原始代码的许多部分（另外，我知道将所有内容都写在一个函数中并不是一个好习惯，但是我发现在尝试理解某些东西时更容易）。
但我现在遇到的最大问题是它不起作用！无论我向我的函数提供什么输入消息，它都会给出相同的输出：
0x6a09e667f3bcc9080xbb67ae8584caa73b0x3c6ef372fe94f82b0xa54ff53a5f1d36f1
0x510e527fade682d10x9b05688c2b3e6c1f0x1f83d9abfb41bd6b0x5be0cd19137e2179
我在底部写了一段代码，用来和python的hashlib模块进行对比
我哪里出错了，我该如何解决？
编辑： 如评论中所述，我尝试输入更长的 message 字符串，代码似乎正在工作（尽管它仍然提供比 hashlib 更长的输出）：
message = "This is a string to be hashed. I'll try to make this string as long as possible by adding" \
"as much information to it as I can, in the hopes that this string would somehow become longer than" \
"128 bits and my code can run properly. Hopefully, this is already longer than 128 bits, so lets see" \
"how it works..."
hash: 0x6fcc0f346f2577800x334bd9b6c1178a970x90964a3f45f7b5bb0xc14033d12f6607e60xb598bea0a8b0ac1e0x116b0e134691ab540x73d88e77e5b862ba0x89181da7462c5574
message = "This is a string to be hashed. I'll try to make this string as long as possible by adding" \
"as much information to it as I can, in the hopes that this string would somehow become longer than"
hash: 0x166e40ab03bc98750xe81fe34168b6994f0xe56b81bd5972b5560x8789265c3a56b30b0x2c810d652ea7b1550xa23ca2704602a8240x12ffb1ec8f3dd6d10x88c29f84cbef8988
您总是需要填充消息。填充和添加长度始终是 SHA-2 过程的最后一步。目前您没有执行最后一步（完成）。
以下是我为您指出正确方向的最后两条评论：
So generally you try and take one 128 byte block from the binary message, update the hash state using the information in that block, then move to the next one until you have a partial or 0 byte block. That block you need to pad & add size indication (in bits) and process. If you've not enough space for the padding / size indication then you need yet another block consisting entirely of padding and the size indication. If you read carefully, then you always process at least one block.
和
Hmm, it is already in sha_backend_digest (the 0x80 followed by zero bytes and the length which is input size * 8 (_counter << 3).
但是您当然需要执行该操作并且不能跳过任何步骤。
我是这个领域的新手，正在尝试学习一些有关如何编写加密哈希函数的知识。
为了动手实践，我尝试为 Python 3.6 及更高版本更新 PySHA2 算法（原始版本不适用于 Python 2.5+ 和作者说他不会解决这个问题）。我不打算将此算法用于任何工作，只是为了知识而编写代码。
我已经走到这一步了：
import copy
import struct
_initial_hashes = [0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
0x510e527fade682d1, 0x9b05688c2b3e6c1f, 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179]
_round_constants = [0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118,
0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30,
0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3,
0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817]
def _rit_rot(on: int, by: int) -> int:
"""
helper function for right rotation as it isn't done by a simple bitwise operation (xor is done by '^')
:param on: value to be rotated
:param by: value by which to rotate
:return: right rotated 'on'
"""
return ((on >> by) | (on << (64 - by))) & 0xFFFFFFFFFFFFFFFF
def hash_main(chunk):
global _initial_hashes, _round_constants
# start the hashing process
# to begin, create a place to store the 80 words that we'll make
words = [0] * 80
# first 16 words will be saved without any changes
words[:16] = struct.unpack('!16Q', chunk)
# extend these 16 words into the remaining 64 words of 'message schedule array'
for i in range(16, 80):
part_1 = _rit_rot(words[i - 15], 1) ^ _rit_rot(words[i - 15], 8) ^ (words[i - 15] >> 7)
part_2 = _rit_rot(words[i - 2], 19) ^ _rit_rot(words[i - 2], 61) ^ (words[i - 2] >> 6)
words[i] = (words[i - 16] + part_1 + words[i - 7] + part_2) & 0xFFFFFFFFFFFFFFFF
# create the working variables
a, b, c, d, e, f, g, h = _initial_hashes
# start the compression function
for z in range(80):
var_1 = _rit_rot(a, 28) ^ _rit_rot(a, 34) ^ _rit_rot(a, 39)
var_2 = _rit_rot(e, 14) ^ _rit_rot(e, 18) ^ _rit_rot(e, 41)
var_3 = (a & b) ^ (a & c) ^ (b & c)
var_4 = (e & f) ^ ((~e) & g)
temp_1 = var_1 + var_3
temp_2 = h + var_2 + var_4 + _round_constants[z] + words[z]
# remix the hashes
h = g
g = f
f = e
e = (d + temp_2) & 0xFFFFFFFFFFFFFFFF
d = c
c = b
b = a
a = (temp_1 + temp_2) & 0xFFFFFFFFFFFFFFFF
# add this chunk to initial hashes
_initial_hashes = [(x + y) & 0xFFFFFFFFFFFFFFFF for x, y in zip(_initial_hashes,
[a, b, c, d, e, f, g, h])]
def _sha_backend_update(text_copy, _buffer, _counter):
"""
backend function that hashes given string
"""
global _initial_hashes, _round_constants
# create variables for cycling
_buffer += text_copy
_counter += len(text_copy)
# assert the variables are correct
if not text_copy:
return
if type(text_copy) is not str:
raise TypeError("Invalid Object! Please enter a valid string for hashing!")
# break the buffer into 128-bit chunks
while len(_buffer) >= 128:
chunk = _buffer[:128].encode()[1:]
hash_main(chunk)
_buffer = _buffer[128:]
def sha_backend_digest(text_to_hash: str, _buffer: str, _counter: int,
_output_size: int, hex_output: bool = False):
# initialize variables
variable_x = _counter & 0x7F
length = str(struct.pack('!Q', _counter << 3))
# set the thresholds
if variable_x < 112:
padding_len = 111 - variable_x
else:
padding_len = 239 - variable_x
# make a copy of the text_to_hash before starting hashing
text_copy = copy.deepcopy(text_to_hash)
m = '\x80' + ('\x00' * (padding_len + 8)) + length
# run the update function
_sha_backend_update(text_copy, _buffer, _counter)
# return the hash value
return_val = [hex(stuff) for stuff in _initial_hashes[:_output_size]]
if hex_output is True:
return_val = [int(stuff, base=16) for stuff in return_val]
return return_val
return ''.join(return_val)
def sha_512(text_to_hash: str, hex_digest: bool = False) -> str:
"""
frontend function for SHA512 hashing
:return: hashed string
"""
# before anything, check if the input is correct
if not text_to_hash:
return ""
if type(text_to_hash) is not str:
raise TypeError("Invalid content! Please provide content in correct format for hashing!")
# initialize default variables
_buffer = ''
_counter = 0
_output_size = 8
# start the backend function
return sha_backend_digest(text_to_hash, _buffer, _counter, _output_size, hex_output=hex_digest)
message = "This is a string to be hashed"
from hashlib import sha512
print("hashlib gives: ", sha512(message.encode()).hexdigest())
print("I give: ", sha_512(message))
很明显，我不理解这个算法中的很多东西，并且从字面上复制了原始代码的许多部分（另外，我知道将所有内容都写在一个函数中并不是一个好习惯，但是我发现在尝试理解某些东西时更容易）。
但我现在遇到的最大问题是它不起作用！无论我向我的函数提供什么输入消息，它都会给出相同的输出：
0x6a09e667f3bcc9080xbb67ae8584caa73b0x3c6ef372fe94f82b0xa54ff53a5f1d36f1
0x510e527fade682d10x9b05688c2b3e6c1f0x1f83d9abfb41bd6b0x5be0cd19137e2179
我在底部写了一段代码，用来和python的hashlib模块进行对比
我哪里出错了，我该如何解决？
编辑： 如评论中所述，我尝试输入更长的 message 字符串，代码似乎正在工作（尽管它仍然提供比 hashlib 更长的输出）：
message = "This is a string to be hashed. I'll try to make this string as long as possible by adding" \
"as much information to it as I can, in the hopes that this string would somehow become longer than" \
"128 bits and my code can run properly. Hopefully, this is already longer than 128 bits, so lets see" \
"how it works..."
hash: 0x6fcc0f346f2577800x334bd9b6c1178a970x90964a3f45f7b5bb0xc14033d12f6607e60xb598bea0a8b0ac1e0x116b0e134691ab540x73d88e77e5b862ba0x89181da7462c5574
message = "This is a string to be hashed. I'll try to make this string as long as possible by adding" \
"as much information to it as I can, in the hopes that this string would somehow become longer than"
hash: 0x166e40ab03bc98750xe81fe34168b6994f0xe56b81bd5972b5560x8789265c3a56b30b0x2c810d652ea7b1550xa23ca2704602a8240x12ffb1ec8f3dd6d10x88c29f84cbef8988
您总是需要填充消息。填充和添加长度始终是 SHA-2 过程的最后一步。目前您没有执行最后一步（完成）。
以下是我为您指出正确方向的最后两条评论：
So generally you try and take one 128 byte block from the binary message, update the hash state using the information in that block, then move to the next one until you have a partial or 0 byte block. That block you need to pad & add size indication (in bits) and process. If you've not enough space for the padding / size indication then you need yet another block consisting entirely of padding and the size indication. If you read carefully, then you always process at least one block.
和
Hmm, it is already in
sha_backend_digest(the0x80followed by zero bytes and the length which is input size * 8(_counter << 3).
但是您当然需要执行该操作并且不能跳过任何步骤。