How To Solve an expire key error (EXPKEYSIG or KEYEXPIRED) in Ubuntu using apt

How To Solve an expire key error (EXPKEYSIG or KEYEXPIRED) in Ubuntu using apt

If you are facing signatures were invalid or EXPKEYSIG or KEYEXPIRED error in Debian or Ubuntu then this might be help you to solve the problem.
For example:- 

Note:-  All command are executed by root privileges.

"Err:4 http://repo.mysql.com/apt/ubuntu bionic InRelease       
  The following signatures were invalid: EXPKEYSIG 8C718D3B5072E1F5 MySQL Release Engineering " 

Step 1:- 
Use apt-key utility to list down all known key's.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

huntechpedia@Ubuntu-VM:~$ apt-key list /etc/apt/trusted.gpg -------------------- pub dsa1024 2003-02-03 [SCA] [expired: 2019-02-17] A4A9 4068 76FC BD3C 4567 70C8 8C71 8D3B 5072 E1F5 uid [ expired] MySQL Release Engineering pub rsa4096 2016-04-12 [SC] EB4C 1BFD 4F04 2F6D DDCC EC91 7721 F63B D38B 4796 uid [ unknown] Google Inc. (Linux Packages Signing Authority) sub rsa4096 2016-04-12 [S] [expires: 2019-04-12] sub rsa4096 2017-01-24 [S] [expires: 2020-01-24] pub rsa2048 2016-06-22 [SC] [expires: 2021-06-21] D404 0146 BE39 7250 9FD5 7FC7 1F30 45A5 DF75 87C3 uid [ unknown] Skype Linux Client Repository sub rsa2048 2016-06-22 [E] [expires: 2021-06-21] pub rsa4096 2017-03-13 [SC] 8CAE 012E BFAC 38B1 7A93 7CD8 C5E2 2450 0C12 89C0 uid [ unknown] TeamViewer GmbH (TeamViewer Linux 2017) sub rsa4096 2017-03-13 [E] pub rsa4096 2016-10-05 [SC] 72EC F46A 56B4 AD39 C907 BBB7 1646 B01B 86E5 0310 uid [ unknown] Yarn Packaging sub rsa4096 2016-10-05 [E] sub rsa4096 2019-01-02 [S] [expires: 2020-02-02] sub rsa4096 2019-01-11 [S] [expires: 2020-02-02] /etc/apt/trusted.gpg.d/microsoft.gpg ------------------------------------ pub rsa2048 2015-10-28 [SC] BC52 8686 B50D 79E3 39D3 721C EB3E 94AD BE12 29CF uid [ unknown] Microsoft (Release signing) /etc/apt/trusted.gpg.d/ubuntu-keyring-2012-archive.gpg ------------------------------------------------------ pub rsa4096 2012-05-11 [SC] 790B C727 7767 219C 42C8 6F93 3B4F E6AC C0B2 1F32 uid [ unknown] Ubuntu Archive Automatic Signing Key (2012) /etc/apt/trusted.gpg.d/ubuntu-keyring-2012-cdimage.gpg ------------------------------------------------------ pub rsa4096 2012-05-11 [SC] 8439 38DF 228D 22F7 B374 2BC0 D94A A3F0 EFE2 1092 uid [ unknown] Ubuntu CD Image Automatic Signing Key (2012)

You can directly find expire key adding grep in command.

 apt-key list | grep expired

You will get output like,
 

  pub   dsa1024 2003-02-03 [SCA] [expired: 2019-02-17]

   
Step 2:-
Now we are going to update the KEY.
We are using key which we found in step1.
Command to update key is,

  apt-key adv --keyserver keys.gnupg.net --recv-keys [KEY] 

Now put key at the place of [KEY] in above command,

  apt-key adv --keyserver keys.gnupg.net --recv-keys A4A9406876FCBD3C456770C88C718D3B5072E1F5 

You will get output like,

huntechpedia@Ubuntu-VM:~$ sudo apt-key adv --keyserver keys.gnupg.net --recv-keys A4A9406876FCBD3C456770C88C718D3B5072E1F5
[sudo] password for krawler: 
Executing: /tmp/apt-key-gpghome.bhdLfYcSQ5/gpg.1.sh --keyserver keys.gnupg.net --recv-keys A4A9406876FCBD3C456770C88C718D3B5072E1F5
gpg: key 8C718D3B5072E1F5: 3 duplicate signatures removed
gpg: key 8C718D3B5072E1F5: 96 signatures not checked due to missing keys
gpg: key 8C718D3B5072E1F5: "MySQL Release Engineering " 23 new signatures
gpg: Total number processed: 1
gpg:         new signatures: 23
 

Step 3:-

Now you have to run update and upgrade command.

  apt update -y && apt upgrade -y 

That's it. Done!!! 
Problem Solved. Let me know it help you or not in comments.