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Using GPG and OpenSSL to Encrypt

Using gpg, and openssl to encrypt files. They are both available for all most commonly used operating systems.

I have used Gnupg to encrypt my private files, specially those that I upload to the clouds, for a long time. I used to encrypt to self, using my own key, then later moved to symmetric encryption only. The command is easy:

Using Gnupg

To encrypt:

gpg --cipher-algo aes256 --symmetric file.txt

Adding the option --armor to the above will produce an ASCII armoured encrypted file.

To decrypt:

gpg --output file.txt --decrypt file.txt.{gpg,asc}

Use asc ending to decrypt, if encrypted with the --armor option.

Using OpenSSL

Although Gnupg is common, openssl is even more so. Encrypting with openssl is a breeze as well. Even though this should work on earlier versions of openssl, I am going to assume openssl v1.1 and up:

To encrypt:

openssl enc -aes-256-cbc -md sha256 -iter 1000 -in file.txt -out file.txt.enc

To decrypt:

openssl enc -d -aes-256-cbc -md sha256 -iter 1000 -in file.txt.enc -out file.txt

If a base64 output is preferred, then the option -a should be added to both, encryption and decryption.

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