How to GPG encrypt file to different standard than default - encryption

My GPG version 2.2.12 is initialised # AES256. How can I encrypt files at a more secure RSA-4096?

Related

How to decrypt a source file in palantir-foundry?

How to decrypt a file in Palantir either while pulling the file thru SFTP sync or after receiving the file at Foundry end.
File is encrypted [symmetric (passphrase)] in a linux system using gpg utility.
Command used to decrypt the file in a linux system:
gpg --batch --passphrase <<passphrase>> --output decrypted_file.csv --decrypt encrypted_file.csv

Moving a private key without passphrase from a server to another causes request of passphrase by GPG

I generated a key pair using GPG by following command in Debian 8.
gpg --gen-key
I left the passphrase step of key generation empty and just hit the Enter key. After that, I exported private and public key using following commands.
gpg --export-secret-key -a "X" > private.key
gpg --export-key -a "X" > public.key
Then I tried to encrypt a folder using the private key. It was successful and without asking any passphrase the encrypted file was generated.
But When I transferred the public key to another computer with Ubuntu OS 14.04 and import it using following command, gpg requested passphrase. Even, by giving empty passphrase to gpg, it says that passphrase is incorrect.
gpg --import public.key
Furthermore, when I imported the private key in the second computer for encryption, it asks me passphrase again.
Does anyone have any idea what is the problem?
There is no need to export and import keys. Just copy the key files located in ~/.ssh/ on your source machine to the other system.
It was because there exist other keyring in second system before. Indeed, it is required to clear all keys before import

SSL certificate creation

When i created self signed certificate , my company told like this will not be accepted and they gave certificate like how we are getting from CA, like verisign or Godaddy, but that is a .cer file. How can i upload a .cer file in IIS? if i remember correctly we can upload .pfx file only in IIS.IF this is the case how can i convert company given .cer file in to .pfx? do we need to give server name as fully qualified name?
When i was creating self signed one i used mkcert.exe to create .cer file and pvk tool to generate .pfx file, pvk tool is sufficient to generate pfx file or not?
You should convert your cert and you can use openssl to achieve the conversion that you are wanting.
For instance:
openssl pkcs12 -export -out cert.pfx -inkey cert.key -in cert.crt

GPG: How to sign with multiple signatures with different passphrases?

I have a job that runs periodically and signs/encrypts a file like so:
$ gpg --homedir /path/to/.gnupg -r key1#mydomain.com -r key2#mydomain.com --local-user sig1#mydomain.com --batch --passphrase-file /path/to/gpg-password --sign -ea myfile
The command encrypts the file for two recipients: key1#mydomain.com and key2#mydomain.com. It signs the file with sig1#mydomain.com. It runs in batch mode as there is no human interactivity - this is an automated process. It gets the passphrase for the signature from /path/to/gpg-password.
What I would like to do is now sign the file with two signatures at the same time. Like so:
$ gpg --homedir /path/to/.gnupg -r key1#mydomain.com -r key2#mydomain.com --local-user sig1#mydomain.com --local-user sig2#mydomain.com --batch --passphrase-file /path/to/gpg-password --sign -ea myfile
gpg: skipped "sig2#mydomain.com": bad passphrase
It works fine in interactive mode (eg. without --batch), I just have to supply the two passphrases via the command line. However, in batch mode it fails as it tries to get the signatures from the file. The signature is only valid for one of the signing keys.
From the man page:
--passphrase-file file
Read the passphrase from file file. Only the first line will be read from file file. This can only be used if only one passphrase is supplied.
How do I tell it what the password is for each key?
You have different options.
Completely remove the passwords, since they're stored somewhere anyway.
Use the same password (as you already discovered).
Use the gpg-agent and preset the passphrase. I'm unsure whether this is GnuPG 2-only (usually installed as gpg2, maybe to be installed from a gnupg2 package). Presetting the passphrase is as easy as running gpg-preset-passphrase --preset [fingerprint]. You will have to run this command for each of the keys individually, and make sure to cache the passphrase for a given time (at least the processing time of adding all the passphrases, and then signing the file you want to sign).
For the sake of completeness, but impractical: sign the file individually for each key, then take apart the OpenPGP packets and recombine them adding all the signatures one after the other. Signing with multiple keys just creates multiple signature packets.
For anyone else in the same situation as me, I ended up working around this apparent deficiency of gpg by editing one of the signing keys to have the same password as the other (the password stored in the gpg-password file). This doesn't compromise security in this instance since the password is stored in a text file anyway - the real security is the password of the user that this commands runs from and the fact that the secret keys are kept secret). You can change the password on a key by doing gpg --edit-key <key_id>, then passwd. Don't forget to save after.

decrypt encrypted gpg file using external secret key

I encryptd a file using gpg, now I want to decrypt the file.
Is there any way to decrypt the file without need to import the secret file?
We have the secret key in a file called key.sec; can we pass the secret file to gpg as a parameter (when we run the decrypt command from the bash command line) to use when decrypting the encrypted file? Or must we import the secret key then decrypt the encrypted files?
You must add the secret key to a keyring. From the gpg(1) documentation:
--no-default-keyring
Do not add the default keyrings to the list of
keyrings. Note that GnuPG will not operate without any
keyrings, so if you use this option and do not provide
alternate keyrings via --keyring or --secret-keyring,
then GnuPG will still use the default public or secret
keyrings.
You could --import --no-default-keyring --secret-keyring temporary to import the key, use --secret-keyring temporary when decrypting the content, then delete the ~/.gnupg/temporary.gpg file when you're done. But that's just a work-around.
You have to import the secret key to use it but the way that secret keys are managed by GnuPG version 2.x has changed. There is a gpg-agent daemon that handles secret keys access and its use is mandatory from version 2.1.
Here is a way that you can quickly create a temporary keyring to decrypt with a secret key that is contained in a file:
$ mkdir -m 700 ~/.gnupg-temp
$ gpg --homedir .gnupg-temp --import key.sec
$ gpg --homedir .gnupg-temp -d an_ecrypted_file
If you want to clean up afterwards, stop the agent and remove the directory:
$ gpg-connect-agent --homedir .gnupg-temp KILLAGENT /bye
$ rm -r ~/.gnupg-temp
There used to be an option --secret-keyring about which the documentation for version 2.1 has this to say:
This is an obsolete option and ignored. All secret keys are stored in the private-keys-v1.d directory below the GnuPG home directory.
The private-keys-v1.d directory (wthin the --homedir or ~/.gnupg) is owned and operated by the agent.
The objective of the OP Mohammed appears to be keeping his PUBLIC and SECRET key apart. After all, do we want to keep the Secret key with the data it was used to encrypt? Thus, Mohammed's and 10,650+ others (at the time I write this) are interested in if/how it's possible. Indeed it is, and this is how you do it:
The publicly-facing host only has two keys: Both are Public Keys
Your GPG Public key used to encrypt data
Your SSH Public key in .ssh/authorized_keys to facilitate non-interactive logins.
Round-tripping an encrypted file using Public-Secret key separation:
The following bash snippet when executed on the host with the Secret Key will fetch the crypted file from the DMZ host via scp, and squirt the gpg decrypted standard output back onto the DMZ host into a file so it can be read/operated upon. This code is tested and known to work correctly:
echo "$(gpg -d $(scp myuser#192.168.1.10:/home/myuser/test-gpg.txt.asc .;ls ./test-gpg.txt.asc))" | ssh myuser#192.168.1.10 'cat > /home/myuser/test-gpg.txt'
Note that you will still be prompted for a password once decryption begins. But once the password is supplied, the script continues and injects the decrypted gpg stream into a file on DMZ host.
And don't forget to do an rm test-gpg.txt of the decrypted file once the operation that required it's contents to be readable has been completed.
So yes, very possible to keep your secret key apart from the publicly accessible host where encryption occurs and your secret key tucked safely away in a host outside of that DMZ. HTH- Terrence Houlahan

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