I came across the following error when trying to update Debian packages.
*********@*******:~$ sudo apt-get update
...
Err:11 https://packages.sury.org/php stretch InRelease
The following signatures were invalid: EXPKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key <deb@sury.org>
Get:15 https://packages.cloud.google.com/apt cloud-sdk/main amd64 Packages [154 kB]
Fetched 161 kB in 1s (134 kB/s)
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files
will be used. GPG error: https://packages.sury.org/php stretch InRelease: The following signatures were invalid: EX
PKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key <deb@sury.org>
W: Failed to fetch https://packages.sury.org/php/dists/stretch/InRelease The following signatures were invalid: EX
PKEYSIG B188E2B695BD4743 DEB.SURY.ORG Automatic Signing Key <deb@sury.org>
W: Some index files failed to download. They have been ignored, or old ones used instead.It turned out to be a known expired key issue occurred recently. The following commands should fix it.
sudo apt-key del B188E2B695BD4743
sudo wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg