security - apt 找不到公钥 6DB5542C356545CF

Question

运行 sudo apt update 并收到以下 Heroku 存储库错误，表明签名验证失败且缺少公钥 6DB5542C356545CF。我在网上能找到的关于这个 key 的信息只有日语或韩语，我都看不懂，翻译它们也没有透露任何特别有用的信息。我担心这可能是 MITM 攻击，有人有任何信息或建议吗？

完整的错误信息:

W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://cli-assets.heroku.com/apt ./ InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6DB5542C356545CF
W: Failed to fetch https://cli-assets.heroku.com/apt/./InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6DB5542C356545CF
W: Some index files failed to download. They have been ignored, or old ones used instead.

Answer 1

执行:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6DB5542C356545CF

或

curl https://cli-assets.heroku.com/apt/release.key | sudo apt-key add -

然后

sudo apt-get update