如何解决如何使用python中的摘要验证文件的完整性SHA256SUMS
我有一组文件和一个SHA256SUMS digest file，其中每个文件包含一个sha256()哈希。用python验证文件完整性的最佳方法是什么？
例如，这是我下载Debian 10网络安装程序SHA256SUMS摘要文件并以BASH下载/验证其MANIFEST文件的方式
user@host:~$ wget http://ftp.nl.debian.org/debian/dists/buster/main/installer-amd64/current/images/SHA256SUMS
--2020-08-25 02:11:20-- http://ftp.nl.debian.org/debian/dists/buster/main/installer-amd64/current/images/SHA256SUMS
Resolving ftp.nl.debian.org (ftp.nl.debian.org)... 130.89.149.21,2001:67c:2564:a120::21
Connecting to ftp.nl.debian.org (ftp.nl.debian.org)|130.89.149.21|:80... connected.
HTTP request sent,awaiting response... 200 OK
Length: 75295 (74K)
Saving to: ‘SHA256SUMS’
SHA256SUMS 100%[===================>] 73.53K 71.7KB/s in 1.0s
2020-08-25 02:11:22 (71.7 KB/s) - ‘SHA256SUMS’ saved [75295/75295]
user@host:~$ wget http://ftp.nl.debian.org/debian/dists/buster/main/installer-amd64/current/images/MANIFEST
--2020-08-25 02:11:27-- http://ftp.nl.debian.org/debian/dists/buster/main/installer-amd64/current/images/MANIFEST
Resolving ftp.nl.debian.org (ftp.nl.debian.org)... 130.89.149.21,awaiting response... 200 OK
Length: 1709 (1.7K)
Saving to: ‘MANIFEST’
MANIFEST 100%[===================>] 1.67K --.-KB/s in 0s
2020-08-25 02:11:28 (128 MB/s) - ‘MANIFEST’ saved [1709/1709]
user@host:~$ sha256sum --check --ignore-missing SHA256SUMS
./MANIFEST: OK
user@host:~$
在python中执行相同操作（下载并使用MANIFEST文件验证Debian 10 SHA256SUMS文件的完整性）的最佳方法是什么？
解决方法
您可以按照此博客文章中所述计算每个文件的sha256sum：
https://www.quickprogrammingtips.com/python/how-to-calculate-sha256-hash-of-a-file-in-python.html
生成新清单文件的示例实现可能类似于：
import hashlib
from pathlib import Path
# Your output file
output_file = "manifest-check"
# Your target directory
p = Path('.')
sha256_hash = hashlib.sha256()
with open(output_file,"w") as out:
# Iterate over the files in the directory
for f in p.glob("**/*"):
# Process files only (no subdirs)
if f.is_file():
with open(filename,"rb") as f:
# Read the file by chunks
for byte_block in iter(lambda: f.read(4096),b""):
sha256_hash.update(byte_block)
out.write(f + "\t" + sha256_hash.hexdigest() + "\n")
或者，这似乎可以通过manifest-checker pip软件包来实现。
您可以在这里查看其来源 https://github.com/TonyFlury/manifest-checkerand针对python 3进行调整
,以下python脚本实现了名为integrity_is_ok()的函数，该函数采用SHA256SUMS文件的路径和要验证的文件列表，如果有任何文件，则返回False无法验证，True则无法验证。
#!/usr/bin/env python3
from hashlib import sha256
import os
# Takes the path (as a string) to a SHA256SUMS file and a list of paths to
# local files. Returns true only if all files' checksums are present in the
# SHA256SUMS file and their checksums match
def integrity_is_ok( sha256sums_filepath,local_filepaths ):
# first we parse the SHA256SUMS file and convert it into a dictionary
sha256sums = dict()
with open( sha256sums_filepath ) as fd:
for line in fd:
# sha256 hashes are exactly 64 characters long
checksum = line[0:64]
# there is one space followed by one metadata character between the
# checksum and the filename in the `sha256sum` command output
filename = os.path.split( line[66:] )[1].strip()
sha256sums[filename] = checksum
# now loop through each file that we were asked to check and confirm its
# checksum matches what was listed in the SHA256SUMS file
for local_file in local_filepaths:
local_filename = os.path.split( local_file )[1]
sha256sum = sha256()
with open( local_file,'rb' ) as fd:
data_chunk = fd.read(1024)
while data_chunk:
sha256sum.update(data_chunk)
data_chunk = fd.read(1024)
checksum = sha256sum.hexdigest()
if checksum != sha256sums[local_filename]:
return False
return True
if __name__ == '__main__':
script_dir = os.path.split( os.path.realpath(__file__) )[0]
sha256sums_filepath = script_dir + '/SHA256SUMS'
local_filepaths = [ script_dir + '/MANIFEST' ]
if integrity_is_ok( sha256sums_filepath,local_filepaths ):
print( "INFO: Checksum OK" )
else:
print( "ERROR: Checksum Invalid" )
以下是执行示例：
user@host:~$ wget http://ftp.nl.debian.org/debian/dists/buster/main/installer-amd64/current/images/SHA256SUMS
--2020-08-25 22:40:16-- http://ftp.nl.debian.org/debian/dists/buster/main/installer-amd64/current/images/SHA256SUMS
Resolving ftp.nl.debian.org (ftp.nl.debian.org)... 130.89.149.21,2001:67c:2564:a120::21
Connecting to ftp.nl.debian.org (ftp.nl.debian.org)|130.89.149.21|:80... connected.
HTTP request sent,awaiting response... 200 OK
Length: 75295 (74K)
Saving to: ‘SHA256SUMS’
SHA256SUMS 100%[===================>] 73.53K 201KB/s in 0.4s
2020-08-25 22:40:17 (201 KB/s) - ‘SHA256SUMS’ saved [75295/75295]
user@host:~$ wget http://ftp.nl.debian.org/debian/dists/buster/main/installer-amd64/current/images/MANIFEST
--2020-08-25 22:40:32-- http://ftp.nl.debian.org/debian/dists/buster/main/installer-amd64/current/images/MANIFEST
Resolving ftp.nl.debian.org (ftp.nl.debian.org)... 130.89.149.21,awaiting response... 200 OK
Length: 1709 (1.7K)
Saving to: ‘MANIFEST’
MANIFEST 100%[===================>] 1.67K --.-KB/s in 0s
2020-08-25 22:40:32 (13.0 MB/s) - ‘MANIFEST’ saved [1709/1709]
user@host:~$ ./sha256sums_python.py
INFO: Checksum OK
user@host:~$
上面代码的一部分改编自Ask Ubuntu上的以下答案：
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