Ubuntu更新失败：软件更新器提示网络连接问题，Steam仓库签名验证错误求助

问题描述 #

我现在碰到了Ubuntu更新的麻烦：用软件更新器操作时，一直弹出“Check your internet connection”的提示；换成终端执行更新命令，结果发现是Steam仓库的签名验证出了问题。

终端执行sudo apt-get update的输出如下：

Hit:1 http://lv.archive.ubuntu.com/ubuntu jammy InRelease

Get:2 http://repo.steampowered.com/steam stable InRelease [2 861 B]

Get:3 http://lv.archive.ubuntu.com/ubuntu jammy-updates InRelease [119 kB]

Err:2 http://repo.steampowered.com/steam stable InRelease

The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F24AEA9FB05498B7

Get:4 http://security.ubuntu.com/ubuntu jammy-security InRelease [110 kB]

Get:5 http://lv.archive.ubuntu.com/ubuntu jammy-backports InRelease [107 kB]

Get:6 http://lv.archive.ubuntu.com/ubuntu jammy-updates/main amd64 DEP-11 Metadata [102 kB]

Get:7 http://lv.archive.ubuntu.com/ubuntu jammy-updates/universe amd64 DEP-11 Metadata [269 kB]

Get:8 http://lv.archive.ubuntu.com/ubuntu jammy-updates/multiverse amd64 DEP-11 Metadata [940 B]

Get:9 http://lv.archive.ubuntu.com/ubuntu jammy-backports/main amd64 DEP-11 Metadata [8 016 B]

Get:10 http://lv.archive.ubuntu.com/ubuntu jammy-backports/universe amd64 DEP-11 Metadata [12,5 kB]

Get:11 http://security.ubuntu.com/ubuntu jammy-security/main amd64 DEP-11 Metadata [41,6 kB]

Get:12 http://security.ubuntu.com/ubuntu jammy-security/universe amd64 DEP-11 Metadata [17,1 kB]

Reading package lists... Done

W: GPG error: http://repo.steampowered.com/steam stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F24AEA9FB05498B7

E: The repository 'http://repo.steampowered.com/steam stable InRelease' is not signed.

N: Updating from such a repository can't be done securely, and is therefore disabled by default.

N: See apt-secure(8) manpage for repository creation and user configuration details.

我试过用老办法添加密钥，但系统提示apt-key已经被弃用，而且执行后完全没效果：

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys F24AEA9FB05498B7

对应的输出是：

Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).

Executing: /tmp/apt-key-gpghome.k7KsmtABvG/gpg.1.sh --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys F24AEA9FB05498B7

gpg: key F24AEA9FB05498B7: "Valve Corporation <linux@steampowered.com>" not changed

gpg: Total number processed: 1

gpg:              unchanged: 1

现在实在没辙了，求各位大佬支招！

解决方案 #

你遇到的问题核心是apt-key已经被Ubuntu官方弃用了，虽然你成功下载了密钥，但老方法不会把密钥放到APT现在认可的验证路径里。试试下面的步骤，应该能彻底解决：

1. 先下载Steam的官方公钥，转换成APT支持的格式并存放到指定目录：

curl -fsSL http://repo.steampowered.com/steam/archive/stable/steam.gpg | sudo gpg --dearmor -o /usr/share/keyrings/steam.gpg

2. 接下来修改Steam的源配置文件，让APT知道用刚才添加的密钥来验证这个仓库的签名。先打开配置文件：

sudo nano /etc/apt/sources.list.d/steam.list

• 如果这个文件不存在，直接创建它，然后把下面的内容复制进去：

deb [arch=amd64,i386 signed-by=/usr/share/keyrings/steam.gpg] http://repo.steampowered.com/steam/ stable steam
deb-src [arch=amd64,i386 signed-by=/usr/share/keyrings/steam.gpg] http://repo.steampowered.com/steam/ stable steam

• 如果文件已经存在，把里面的内容替换成上面的，重点是要加上signed-by=/usr/share/keyrings/steam.gpg这部分，告诉APT验证签名时用哪个密钥。

3. 按Ctrl+O保存文件，Ctrl+X退出编辑器，然后重新执行更新命令：

sudo apt-get update

这样Steam仓库的签名验证错误就应该解决了，软件更新器之前提示的“网络连接问题”其实是更新失败的误导性提示，搞定签名问题后，更新就能正常进行啦～

备注：内容来源于stack exchange，提问作者Nikita Ivanovs