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

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

Related

How do I derive a SHA256 fingerprint from either a public key or MD5 fingerprint?

I received a public key generated by "SAP SuccessFactors" from someone who needs to connect to an SFTP, but in order for me to import the public key, I need to provide a SHA256 fingerprint.
Apparently "SAP SuccessFactors" can only produce an MD5 fingerprint. I've tried running the command
ssh-keygen -lf <path>.fakekeyname.pub
but I get an error
fakekeyname.pub is not a public key file
In opening up the public key file, the header says
begin ssh2 public key
whereas I'm used to seeing something along the lines of ssh-rsa.
Apologies in advance if this seems immediately obvious, but I would sincerely appreciate some guidance or advice.
Thanks very much!
You can use ssh-keygen. First you would need to convert the file to pem format first
ssh-keygen -i -m PKCS8 -f pubkey.pem > NEWpubkey.pem
Next get the fingerprint
and then you can get the sha256 value from it:
ssh-keygen -lf NEWpubkey.pem
for reference see this post:get SHA256 hash of public key
Edit: For Pub files this could work ssh-keygen -E sha256 -lf sample.pub see How to Calculate Fingerprint From SSH RSA Public Key in Java?

how to use openssh keys with paramiko [duplicate]

I am trying connect to server using following spinet
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ip = ['x.x.x.x']
key_file = "/Users/user/.ssh/id_rsa"
key = paramiko.RSAKey.from_private_key_file(key_file)
ssh.load_system_host_keys()
ssh.connect(ips, port=22, username='XYZ', pkey=key, timeout=11)
But I am getting an error:
not a valid RSA private key file
I faced a similar situation and ssh-keygen comes to my help. You should make a copy of id_rsa and convert it to RSA type with ssh-keygen.
To Convert "BEGIN OPENSSH PRIVATE KEY" to "BEGIN RSA PRIVATE KEY"
ssh-keygen -p -m PEM -f ~/.ssh/id_rsa
Recent versions of OpenSSH (7.8 and newer) generate keys in new OpenSSH format by default, which starts with:
-----BEGIN OPENSSH PRIVATE KEY-----
That format is fully supported by the Paramiko since version 2.7.1 (2019-12-09) only.
If you are stuck with an older version of Paramiko, you can use ssh-keygen to convert the key to the classic OpenSSH format:
ssh-keygen -p -f file -m pem -P passphrase -N passphrase
(if the key is not encrypted with a passphrase, use "" instead of passphrase)
For Windows users: Note that ssh-keygen.exe is now built-in in Windows 10. And can be downloaded from Microsoft Win32-OpenSSH project for older versions of Windows.
On Windows, you can also use PuTTYgen (from PuTTY package):
Start PuTTYgen
Load the key
Go to Conversions > Export OpenSSH key.
For RSA keys, it will use the classic format.
If you are creating a new key with ssh-keygen, just add -m PEM to generate the new key in the classic format:
ssh-keygen -m PEM
Note that you can get the error, also when you are trying to use a completely different key format, like ssh.com or PuTTY .ppk. Then you will have to convert the key in any case.
For ssh.com format, see Paramiko: "not a valid DSA private key file".
For PuTTY .ppk format, use PuTTYgen as shown above.
The paramiko.RSAKey.from_private_key_file method requires the private key file to be in "PEM" format. Examine the file you're trying to read and see if it begins with a line that says:
-----BEGIN RSA PRIVATE KEY-----
If it doesn't have that line then it's not PEM.
If it's not PEM then you'll have to find some way to create a PEM version of the private key. (EDIT: the original poster used PuTTY's puttygen utility to export the private key into a PEM-format file.)
Make sure that the new file has the same ownership and limited access permissions that the original id_rsa file has, so that nobody can steal the key by reading the file. Then, obviously, modify your paramiko call to read the key from the new PEM-format file.
I have encountered the same error while I was connected with ssh to an Ubuntu VM.
In my terminal SSH_AUTH_SOCK environment variable is not defined, and paramiko throws the not a valid RSA private key file error.
However, if I am connected in a graphical session to the same machine, the graphical terminal has got SSH_AUTH_SOCK defined, and Paramiko is happy.
As a workaround, I have copied the content of SSH_AUTH_SOCK in my SSH terminal and it works better.
As I checked, there was no issue with the path as well permissions(only read permission on the RSA file will work), so the problem was with the Paramiko version.
I updated it using the below command and it resolved the issue for me.
pip3 install paramiko update

Recursive decryption using gpgdir

I have a lot of files that are encrypted with gpg in a lot of directories. So I want to use gpgdir command to decrypt recursively all files in all directories.
The problem is in the use of gpgdir. I installed it correctly and I set the correct defualt key id in my conf file using gpg --list-keys to find the id. But when I use the command
gpgdir -decrypt <directory>
the console gives me back
[+] Executing: gpgdir -decrypt <directory>
Using GnuPG key: 3662FD5E
Password:
I don't know what password I must insert to decrypt the files. I tried with the admin password but doesn't work.
Someone can help me?
Thanks!!

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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