Error in Travis CI build, bad decrypt, digital envelope routines:EVP_DecryptFinal_ex:wrong final block length:evp_enc.c:518:

[forcedotcom]

Error in Travis CI build, bad decrypt, digital envelope routines:EVP_DecryptFinal_ex:wrong final block length:evp_enc.c:518:

[ImagineCRM-vcs]

Finally, I was able to solve it.

The reasons why this was failing:

Trailhead module information about login is out of date, travis login --org was not working- keep throwing "Not found" exception, so I solved it using travis login --org --github-token.
When using travis encrypt-file path-to-secret-file/secret-file.txt path-to-secret-file/secret-file.txt.enc --add I wasn't providing the endpoint, in this case since I was logged to the Org end-point I needed to specify the same in the command by adding --org at the end.
Since Travis-org is moving soon to Travis-com, and Travis-org only fetches public repositories, I needed to move this to Travis-com, so I logged out and logged in again but this time pointing to --com in both commands (login and encrypt-file).
Taking these 3 considerations I was able (finally) to make it work.

Is pretty bad not having this information accessible.

Only information that gave me an idea of what probably was happening was this banner.