如何自动检查 Ubuntu ISO SHA256sum

Question 1

这将自动获取指定风格/版本的正确“SHA256SUM”文件，并根据在指定目录中找到的图像（如果未指定目录，则在当前工作目录中）进行检查；

输入的口味必须是“统一”或列出的口味之一这里；在回答这个问题时，这些是：

edubuntu
kubuntu
lubuntu
mythubuntu
ubuntu-gnome
ubuntukylin
ubuntu-mate
ubuntustudio
xubuntu

输入版本必须是指定风格的有效版本/点版本。

它用于zenity提供一个良好的 GUI 来获取输入；它将只打印匹配的结果（如果有）并让用户选择是否要保留下载的“SHA256SUM”文件；

#!/bin/bash
if [ ! -z "$1" ]; then
  if [ -d "$1" ]; then
    printf "Changing PWD to $1...\n"
    cd "$1"
  else
    printf "$1 is not a valid directory.\n"
    exit 1
  fi
fi
flavour=$(zenity \
  --entry \
  --title "Insert the flavour to check the image against" \
  --text "Insert the flavour to check the image against:" \
  2>/dev/null | \
tr '[:upper:]' '[:lower:]')
printf "Flavour:\t$flavour\n"
version=$(zenity \
  --entry \
  --title "Insert the version to check the image against" \
  --text "Insert the version to check the image against:" \
  2>/dev/null | \
tr '[:upper:]' '[:lower:]')
printf "Version:\t$version\n"
[ "$flavour" = "unity" ] \
&& address="http://releases.ubuntu.com/$version/SHA256SUMS" \
|| address="http://cdimage.ubuntu.com/$flavour/releases/$version/release/SHA256SUMS"
printf "Downloading $address...\n"
wget -q -O SHA256SUMS "$address"
[ $? -ne 0 ] && printf "No SHA256SUMS file found on the server.\n" && rm SHA256SUMS && exit 1
printf "Checking SHA256SUMS...\n"
shasum -a 256 -c SHA256SUMS |& grep 'OK$'
[ $? -eq 0 ] || printf "No matching image found on the target directory.\n"
zenity --question --title "Remove SHA256SUMS?" --text "Remove SHA256SUMS?" 2>/dev/null
[ $? -eq 0 ] && rm SHA256SUMS
exit 0

Ubuntu Desktop 15.04 64 位映像上的示例：

Answer

这将自动获取指定风格/版本的正确“SHA256SUM”文件，并根据在指定目录中找到的图像（如果未指定目录，则在当前工作目录中）进行检查；

输入的口味必须是“统一”或列出的口味之一这里；在回答这个问题时，这些是：

edubuntu
kubuntu
lubuntu
mythubuntu
ubuntu-gnome
ubuntukylin
ubuntu-mate
ubuntustudio
xubuntu

输入版本必须是指定风格的有效版本/点版本。

它用于zenity提供一个良好的 GUI 来获取输入；它将只打印匹配的结果（如果有）并让用户选择是否要保留下载的“SHA256SUM”文件；

#!/bin/bash
if [ ! -z "$1" ]; then
  if [ -d "$1" ]; then
    printf "Changing PWD to $1...\n"
    cd "$1"
  else
    printf "$1 is not a valid directory.\n"
    exit 1
  fi
fi
flavour=$(zenity \
  --entry \
  --title "Insert the flavour to check the image against" \
  --text "Insert the flavour to check the image against:" \
  2>/dev/null | \
tr '[:upper:]' '[:lower:]')
printf "Flavour:\t$flavour\n"
version=$(zenity \
  --entry \
  --title "Insert the version to check the image against" \
  --text "Insert the version to check the image against:" \
  2>/dev/null | \
tr '[:upper:]' '[:lower:]')
printf "Version:\t$version\n"
[ "$flavour" = "unity" ] \
&& address="http://releases.ubuntu.com/$version/SHA256SUMS" \
|| address="http://cdimage.ubuntu.com/$flavour/releases/$version/release/SHA256SUMS"
printf "Downloading $address...\n"
wget -q -O SHA256SUMS "$address"
[ $? -ne 0 ] && printf "No SHA256SUMS file found on the server.\n" && rm SHA256SUMS && exit 1
printf "Checking SHA256SUMS...\n"
shasum -a 256 -c SHA256SUMS |& grep 'OK$'
[ $? -eq 0 ] || printf "No matching image found on the target directory.\n"
zenity --question --title "Remove SHA256SUMS?" --text "Remove SHA256SUMS?" 2>/dev/null
[ $? -eq 0 ] && rm SHA256SUMS
exit 0

Ubuntu Desktop 15.04 64 位映像上的示例：

Question 2

包含 Ubuntu、Kubuntu、Edubuntu Xubuntu 和 Lubuntu 的 MD5 哈希值的官方页面是：

https://help.ubuntu.com/community/UbuntuHashes

选择相关分布并点击 MD5SUMS 文件。

现在检查您下载的 ISO：

md5sum ubuntu-*.iso

将你的机器计算出的哈希值（左侧的字母数字字符串）与Ubuntu哈希页。

半自动方法

Ubuntu 将 MD5 哈希值分发到名为 MD5SUMS 的文件中，该文件位于您发行版的下载页面底部附近http://releases.ubuntu.com。

首先将 MD5SUMS 文件下载到与 iso 相同的目录。然后在终端中运行以下命令。

cd 下载目录

md5sum -c MD5SUMS

md5sum 将生成一堆警告。别担心：OK 消息将隐藏在其中的某个地方！

在这种情况下，您想要的信息位于第七行。

ubuntu-*.iso: OK

Answer

包含 Ubuntu、Kubuntu、Edubuntu Xubuntu 和 Lubuntu 的 MD5 哈希值的官方页面是：

https://help.ubuntu.com/community/UbuntuHashes

选择相关分布并点击 MD5SUMS 文件。

现在检查您下载的 ISO：

md5sum ubuntu-*.iso

将你的机器计算出的哈希值（左侧的字母数字字符串）与Ubuntu哈希页。

半自动方法

Ubuntu 将 MD5 哈希值分发到名为 MD5SUMS 的文件中，该文件位于您发行版的下载页面底部附近http://releases.ubuntu.com。

首先将 MD5SUMS 文件下载到与 iso 相同的目录。然后在终端中运行以下命令。

cd 下载目录

md5sum -c MD5SUMS

md5sum 将生成一堆警告。别担心：OK 消息将隐藏在其中的某个地方！

在这种情况下，您想要的信息位于第七行。

ubuntu-*.iso: OK

Question 3

为了完成这个特定的任务，我编写了自己的 Python 脚本。该脚本针对的是 iso 映像，可以通过以下网址下载 iso 映像：http://cdimage.ubuntu.com，但该网站的内容与您使用的完全相同http://releases.ubuntu.com/，因此它对两者都有效。两个网站都有SHA256SUMS文件，我们将检查。此脚本的基本前提是

下载 iso
计算 iso 的 sha256sum
SHA256SUM从同一页面下载文件
将我们计算的结果与文件中的内容进行比较

脚本源代码

此脚本也可在我的个人 GitHub 仓库，这可能从来没有出现过。

#!/usr/bin/env python3
# Script for automatically downloading and verifying sha256 hashsum
# of iso images provided by http://cdimage.ubuntu.com
import urllib.request
import sys
import os
from hashlib import sha256

def download_file(url):
    print(">>> Retrieving ",url)
    save_as = url.split('/')[-1]
    buffer_size=512
    try:
        with urllib.request.urlopen(url) as response, open(save_as,'wb') as out_file:
            print(response.info())
            print(">>> Writing data:")
            has_data=True
            retrieved = 0
            while has_data:
                 data = response.read(buffer_size)
                 retrieved += len(data)
                 # simple progress message which overwrites itself
                 message = "Retrieved "+str(retrieved)+" bytes"
                 print("\r"+" "*len(message)+"\r",end="")
                 print(message,end="")
                 sys.stdout.flush()
                 if data:
                     out_file.write(data)
                 else:
                    has_data=False
    except Exception as e:
        sys.stderr.write('\n>>> Something went wrong\n')
        sys.stderr.write(str(e))
    else:
        print('\n>>> URL retrieved successfully')
        return(save_as)

def get_sha256sum(file_path):
    sha256sum = sha256()
    with open(file_path, 'rb') as fd:
        data_chunk = fd.read(1024)
        while data_chunk:
              sha256sum.update(data_chunk)
              data_chunk = fd.read(1024)
    return str(sha256sum.hexdigest())

def compare_sha256sums(local_file,sha256sum,hashsum_file):
     remote_hashsum = ""
     with open(hashsum_file) as fd:
         for line in fd:
              words = line.strip().split()
              if words[1].replace('*','') == local_file:
                  remote_hashsum = words[0]
         if not remote_hashsum: 
              sys.stderr.write("\n>>> Error: local file not found in list of SHA256SUMS\n")
              sys.exit(1)
     if remote_hashsum == sha256sum:
         print("Local file ",local_file," with sha256 hashsum ",sha256sum,"matches with sha256sum in remote. All OK.")


def main():
    saved_filename = download_file(sys.argv[1])
    sha256sum = get_sha256sum(saved_filename)
    sha256sums_file_url = "/".join( sys.argv[1].split('/')[:-1] + ['SHA256SUMS'] ) 
    sha256sum_file = download_file( sha256sums_file_url  ) 
    compare_sha256sums(saved_filename,sha256sum,sha256sum_file)

if __name__ == '__main__': main()

测试运行：

bash-4.3$ ./get_iso_and_verify.py  http://cdimage.ubuntu.com/releases/16.04.2/release/ubuntu-16.04.2-preinstalled-server-armhf+raspi2.img.xz
>>> Retrieving  http://cdimage.ubuntu.com/releases/16.04.2/release/ubuntu-16.04.2-preinstalled-server-armhf+raspi2.img.xz
Date: Fri, 07 Jul 2017 21:55:20 GMT
Server: Apache/2.4.18 (Ubuntu)
Last-Modified: Thu, 16 Feb 2017 20:16:12 GMT
ETag: "ee62708-548ab77ea3b00"
Accept-Ranges: bytes
Content-Length: 249964296
Connection: close
Content-Type: application/x-xz


>>> Writing data:
Retrieved 249964296 bytes
>>> URL retrieved successfully
>>> Retrieving  http://cdimage.ubuntu.com/releases/16.04.2/release/SHA256SUMS
Date: Fri, 07 Jul 2017 22:09:47 GMT
Server: Apache/2.4.18 (Ubuntu)
Last-Modified: Fri, 17 Feb 2017 00:06:46 GMT
ETag: "205-548aeb07c5180"
Accept-Ranges: bytes
Content-Length: 517
Connection: close


>>> Writing data:
Retrieved 517 bytes
>>> URL retrieved successfully
Local file  ubuntu-16.04.2-preinstalled-server-armhf+raspi2.img.xz  with sha256 hashsum  60156f9238360dc84267dbde4f334516d580fe540dd523d12d4837c4647d6d8f matches with sha256sum in remote. All OK.
bash-4.3$ cat SHA256SUMS 
60156f9238360dc84267dbde4f334516d580fe540dd523d12d4837c4647d6d8f *ubuntu-16.04.2-preinstalled-server-armhf+raspi2.img.xz
35c9a6b7536e41c19f18033ac5a9b095130d17848126160d6b66cbd09be48f17 *ubuntu-16.04.2-server-arm64.iso
a00d88107eebadf0dde86087ad746d372d33ebdd29ac5cd4fae42a2e031d2b8f *ubuntu-16.04.2-server-powerpc.iso
0a10bada74112c58412ac8778df05abbb69d5983b672e6bbe74fa794cf002a2a *ubuntu-16.04.2-server-ppc64el.iso
253fd0eb5e529c3434729f475c7855463ba87ed7dea4321182b54c5416523897 *ubuntu-16.04.2-server-s390x.iso

Answer

为了完成这个特定的任务，我编写了自己的 Python 脚本。该脚本针对的是 iso 映像，可以通过以下网址下载 iso 映像：http://cdimage.ubuntu.com，但该网站的内容与您使用的完全相同http://releases.ubuntu.com/，因此它对两者都有效。两个网站都有SHA256SUMS文件，我们将检查。此脚本的基本前提是

下载 iso
计算 iso 的 sha256sum
SHA256SUM从同一页面下载文件
将我们计算的结果与文件中的内容进行比较

脚本源代码

此脚本也可在我的个人 GitHub 仓库，这可能从来没有出现过。

#!/usr/bin/env python3
# Script for automatically downloading and verifying sha256 hashsum
# of iso images provided by http://cdimage.ubuntu.com
import urllib.request
import sys
import os
from hashlib import sha256

def download_file(url):
    print(">>> Retrieving ",url)
    save_as = url.split('/')[-1]
    buffer_size=512
    try:
        with urllib.request.urlopen(url) as response, open(save_as,'wb') as out_file:
            print(response.info())
            print(">>> Writing data:")
            has_data=True
            retrieved = 0
            while has_data:
                 data = response.read(buffer_size)
                 retrieved += len(data)
                 # simple progress message which overwrites itself
                 message = "Retrieved "+str(retrieved)+" bytes"
                 print("\r"+" "*len(message)+"\r",end="")
                 print(message,end="")
                 sys.stdout.flush()
                 if data:
                     out_file.write(data)
                 else:
                    has_data=False
    except Exception as e:
        sys.stderr.write('\n>>> Something went wrong\n')
        sys.stderr.write(str(e))
    else:
        print('\n>>> URL retrieved successfully')
        return(save_as)

def get_sha256sum(file_path):
    sha256sum = sha256()
    with open(file_path, 'rb') as fd:
        data_chunk = fd.read(1024)
        while data_chunk:
              sha256sum.update(data_chunk)
              data_chunk = fd.read(1024)
    return str(sha256sum.hexdigest())

def compare_sha256sums(local_file,sha256sum,hashsum_file):
     remote_hashsum = ""
     with open(hashsum_file) as fd:
         for line in fd:
              words = line.strip().split()
              if words[1].replace('*','') == local_file:
                  remote_hashsum = words[0]
         if not remote_hashsum: 
              sys.stderr.write("\n>>> Error: local file not found in list of SHA256SUMS\n")
              sys.exit(1)
     if remote_hashsum == sha256sum:
         print("Local file ",local_file," with sha256 hashsum ",sha256sum,"matches with sha256sum in remote. All OK.")


def main():
    saved_filename = download_file(sys.argv[1])
    sha256sum = get_sha256sum(saved_filename)
    sha256sums_file_url = "/".join( sys.argv[1].split('/')[:-1] + ['SHA256SUMS'] ) 
    sha256sum_file = download_file( sha256sums_file_url  ) 
    compare_sha256sums(saved_filename,sha256sum,sha256sum_file)

if __name__ == '__main__': main()

测试运行：

bash-4.3$ ./get_iso_and_verify.py  http://cdimage.ubuntu.com/releases/16.04.2/release/ubuntu-16.04.2-preinstalled-server-armhf+raspi2.img.xz
>>> Retrieving  http://cdimage.ubuntu.com/releases/16.04.2/release/ubuntu-16.04.2-preinstalled-server-armhf+raspi2.img.xz
Date: Fri, 07 Jul 2017 21:55:20 GMT
Server: Apache/2.4.18 (Ubuntu)
Last-Modified: Thu, 16 Feb 2017 20:16:12 GMT
ETag: "ee62708-548ab77ea3b00"
Accept-Ranges: bytes
Content-Length: 249964296
Connection: close
Content-Type: application/x-xz


>>> Writing data:
Retrieved 249964296 bytes
>>> URL retrieved successfully
>>> Retrieving  http://cdimage.ubuntu.com/releases/16.04.2/release/SHA256SUMS
Date: Fri, 07 Jul 2017 22:09:47 GMT
Server: Apache/2.4.18 (Ubuntu)
Last-Modified: Fri, 17 Feb 2017 00:06:46 GMT
ETag: "205-548aeb07c5180"
Accept-Ranges: bytes
Content-Length: 517
Connection: close


>>> Writing data:
Retrieved 517 bytes
>>> URL retrieved successfully
Local file  ubuntu-16.04.2-preinstalled-server-armhf+raspi2.img.xz  with sha256 hashsum  60156f9238360dc84267dbde4f334516d580fe540dd523d12d4837c4647d6d8f matches with sha256sum in remote. All OK.
bash-4.3$ cat SHA256SUMS 
60156f9238360dc84267dbde4f334516d580fe540dd523d12d4837c4647d6d8f *ubuntu-16.04.2-preinstalled-server-armhf+raspi2.img.xz
35c9a6b7536e41c19f18033ac5a9b095130d17848126160d6b66cbd09be48f17 *ubuntu-16.04.2-server-arm64.iso
a00d88107eebadf0dde86087ad746d372d33ebdd29ac5cd4fae42a2e031d2b8f *ubuntu-16.04.2-server-powerpc.iso
0a10bada74112c58412ac8778df05abbb69d5983b672e6bbe74fa794cf002a2a *ubuntu-16.04.2-server-ppc64el.iso
253fd0eb5e529c3434729f475c7855463ba87ed7dea4321182b54c5416523897 *ubuntu-16.04.2-server-s390x.iso

如何自动检查 Ubuntu ISO SHA256sum

答案1

答案2

半自动方法

答案3

脚本源代码

测试运行：

相关内容