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Background:
I have a GPG encrypted secret that must not be written to file unencrypted.
Let say that it lives at ~/.secrets/.mysecret.gpg.
Running gpg ~/.secrets/.mysecret.gpg unencrypts the .mysecret.gpg and saves it to file at .mysecret (unacceptable). Running gpg -d ~/.secrets/.mysecret.gpg prints the decrypted secret only (thank you JustinC).
To avoid the stderr and to encode it in base64 for my use purpose, I wrote this shell function as a convenience method:
keyreader() {
local gpg_file=$1
echo -n "$(gpg -d "$gpg_file" 2> /dev/null)" | base64
}
Running keyreader ~/.secrets/.mysecret.gpg, after entering the password for the encrypted secret, it prints out the base64 encoded, decrypted secret, no output file.
Questions:
When gpg -d ~/.secrets/.mysecret.gpg is run, does gpg write a tmp file that would include the unencrypted .mysecret?
Why does gpg not output a file, .mysecret, when I use the above syntax? (ANSWER: the -d flag was used, again thank you JustinC).
Assuming I use the appropriate $HISTIGNORE identifier before running the command, how can I encrypt a string from the command line to a .gpg AES256 encrypted file without having first written it unencrypted to file?
For Q3, something like:
$ echo "secret info" | gpg --cipher-algo AES265 -c -o secrets_file.txt.gpg
instead of:
$gpg --cipher-algo AES265 -c secrets_file.txt
Again, #JustinC, thank you for your answer.
For completeness, here is my solution for encrypting/decrypting a string in memory only:
encryption:
# notice the space before echo here
# it is the default $HISTIGNORE flag which can be set in the ~/.bashrc
# it keeps this line from being written to the ~/.bash_history file
echo -n 'your secrets here' | gpg -c > ~/.secrets/.mysecret.gpg
# Enter passphrase:
decryption:
# 2> /dev/null: skip printing strerr
gpg -d ~/.secrets/.mysecrets.gpg 2> /dev/null
NB: If you get the error "inappropriate ioctl for device", you may be running on WSL and this may help you:
# https://d.sb/2016/11/gpg-inappropriate-ioctl-for-device-errors
echo -e "use-agent\npinentry-mode loopback" >> ~/.gnupg/gpg.conf
echo "allow-loopback-pinentry" >> ~/.gnupg/gpg-agent.conf
echo RELOADAGENT | gpg-connect-agent
Are you sure gpg -d ~/.secrets/.mysecret.gpg writes decrypted file to disk? It does not for me.
You can use strace to check if any temporal file is created.
I sometimes prevent leaving password in bash history by typing:
PP=`cat`
secret-info ENTER Ctrl+D
echo $PP # will print "secret-info"
The secret-info string is sent to cat program, not to shell, so bash will not save it to history file.
I would like to encrypt a string without writing it to a file.
The way to encrypt a file using GPG is
gpg --encrypt --sign --armor -r <target#email.com> -r <sender#email.com> <filename.txt>
What I want would like is to be able to simply type in a string or a series of numbers where filename.txt is, and have it encrypt that into a file.
gpg --encrypt --sign --armor -r <target#email.com> -r <sender#email.com> <"this is a string that needs to be encrypted">
Is there a way to do this, or is passing in the filename.txt required?
I'm not aware of any option that allows you to pass input as a parameter, but you can simply use a pipe instead:
echo 'foo bar' | gpg -r target#example.com --encrypt
You can of course add all the additional options and commands you used. By using a pipe, the output is not stored as an intermediate file, but echos stdout and gpgs stdin get connected using a small in-memory buffer.
If you are using bash, you can use the HEREDOC syntax, which is useful for multiline strings. You can just copy and paste the multiline string without having to worry about escaping.
gpg -r target#email.com --encrypt -o out.gpg << 'HEREDOC'
first line
second line
HEREDOC
I am trying to add my GPG public key as a part of our appliance installation process. The purpose of it to encrypt any important files like logs before admin pulling them into his local using admin portal and then decrypt them using private key.
The plan is to export public key into a file and make appliance installation process to import it using gpg --import command. But I realized, the key is needed to be trusted/signed before do any encryption.
How to make this key is trusted without any human intervention at the time of installation?
Btw, our appliance os is ubuntu vm and we use kickstart to automate.
Advance thanks for all help.
Your question is really "How do I encrypt to a key without gpg balking at the fact that the key is untrusted?"
One answer is you could sign the key.
gpg --edit-key YOUR_RECIPIENT
sign
yes
save
The other is you could tell gpg to go ahead and trust.
gpg --encrypt --recipient YOUR_RECIPIENT --trust-model always YOUR_FILE
Coincidentally I have a similar situation to the OP - I'm trying to use public/private keys to sign and encrypt firmware for different embedded devices. Since no answer yet shows how to add trust to a key you already have imported, here is my answer.
After creating and testing the keys on a test machine, I exported them as ascii:
$ gpg --export -a <hex_key_id> > public_key.asc
$ gpg --export-secret-keys -a <hex_key_id> > private_key.asc
Then secure-copied and imported them to the build server:
$ gpg --import public_key.asc
$ gpg --import private_key.asc
Important: add trust
Now edit the key to add ultimate trust:
$ gpg --edit-key <user#here.com>
At the gpg> prompt, type trust, then type 5 for ultimate trust, then y to confirm, then quit.
Now test it with a test file:
$ gpg --sign --encrypt --yes --batch --status-fd 1 --recipient "recipient" --output testfile.gpg testfile.txt
which reports
...
[GNUPG:] END_ENCRYPTION
without adding trust, I get various errors (not limited to the following):
gpg: There is no assurance this key belongs to the named user
gpg: testfile.bin: sign+encrypt failed: Unusable public key
There's an easier way to tell GPG to trust all of its keys by using the --trust-model option:
gpg -a --encrypt -r <recipient key name> --trust-model always
From the man page:
--trust-model pgp|classic|direct|always|auto
Set what trust model GnuPG should follow. The models are:
always Skip key validation and assume that used
keys are always fully trusted. You generally
won't use this unless you are using some
external validation scheme. This option also
suppresses the "[uncertain]" tag printed
with signature checks when there is no evidence
that the user ID is bound to the key. Note that
this trust model still does not allow the use
of expired, revoked, or disabled keys.
Add trusted-key 0x0123456789ABCDEF to your ~/.gnupg/gpg.conf replacing the keyid. This is equivalent to ultimately trusting this key which means that certifications done by it will be accepted as valid. Just marking this key as valid without trusting it is harder and either requires a signature or switching the trust-model to direct. If you are sure to only import valid keys you can simply mark all keys as valid by adding trust-model always. In the latter case ensure that you disable automatic key retrieval (not enabled by default).
This worked for me:
Trying to encrypt a file responds with this:
gpg -e --yes -r <uid> <filename>
It is NOT certain that the key belongs to the person named
in the user ID. If you *really* know what you are doing,
you may answer the next question with yes.
Use this key anyway? (y/N)
That causes my shell script to fail.
So I:
$gpg --edit-key <uid>
gpg> trust
Please decide how far you trust this user to correctly verify other
users' keys (by looking at passports, checking fingerprints from
different sources, etc.)
1 = I don't know or won't say
2 = I do NOT trust
3 = I trust marginally
4 = I trust fully
5 = I trust ultimately
m = back to the main menu
Your decision? 5
Do you really want to set this key to ultimate trust? (y/N) y
Please note that the shown key validity is not necessarily correct
unless you restart the program.
gpg> quit
Now the encrypt works properly.
Based on #tersmitten's article and a bit of trial and error, I ended up with the following command line to trust all keys in a given keyring without user interaction. I use it for keys used with both StackEschange Blackbox and hiera-eyaml-gpg:
# The "-E" makes this work with both GNU sed and OS X sed
gpg --list-keys --fingerprint --with-colons |
sed -E -n -e 's/^fpr:::::::::([0-9A-F]+):$/\1:6:/p' |
gpg --import-ownertrust
Personally, I prefer a solution which stores the results in the trustdb file itself rather than depends on user environment outside the shared Git repo.
Here's a trick I've figured out for automation of GnuPG key management, hint heredoc + --command-fd 0 is like magic. Below is an abridged version of one of the scripts that's been written to aid in automation with GnuPG.
#!/usr/bin/env bash
## First argument should be a file path or key id
Var_gnupg_import_key="${1}"
## Second argument should be an integer
Var_gnupg_import_key_trust="${2:-1}"
## Point to preferred default key server
Var_gnupg_key_server="${3:-hkp://keys.gnupg.net}"
Func_import_gnupg_key_edit_trust(){
_gnupg_import_key="${1:-${Var_gnupg_import_key}}"
gpg --no-tty --command-fd 0 --edit-key ${_gnupg_import_key} <<EOF
trust
${Var_gnupg_import_key_trust}
quit
EOF
}
Func_import_gnupg_key(){
_gnupg_import_key="${1:-${Var_gnupg_import_key}}"
if [ -f "${_gnupg_import_key}" ]; then
echo "# ${0##*/} reports: importing key file [${_gnupg_import_key}]"
gpg --no-tty --command-fd 0 --import ${_gnupg_import_key} <<EOF
trust
${Var_gnupg_import_key_trust}
quit
EOF
else
_grep_string='not found on keyserver'
gpg --dry-run --batch --search-keys ${_gnupg_import_key} --keyserver ${Var_gnupg_key_server} | grep -qE "${_grep_string}"
_exit_status=$?
if [ "${_exit_status}" != "0" ]; then
_key_fingerprint="$(gpg --no-tty --batch --dry-run --search-keys ${_gnupg_import_key} | awk '/key /{print $5}' | tail -n1)"
_key_fingerprint="${_key_fingerprint//,/}"
if [ "${#_key_fingerprint}" != "0" ]; then
echo "# ${0##*/} reports: importing key [${_key_fingerprint}] from keyserver [${Var_gnupg_key_server}]"
gpg --keyserver ${Var_gnupg_key_server} --recv-keys ${_key_fingerprint}
Func_import_gnupg_key_edit_trust "${_gnupg_import_key}"
else
echo "# ${0##*/} reports: error no public key [${_gnupg_import_key}] as file or on key server [${Var_gnupg_key_server}]"
fi
else
echo "# ${0##*/} reports: error no public key [${_gnupg_import_key}] as file or on key server [${Var_gnupg_key_server}]"
fi
fi
}
if [ "${#Var_gnupg_import_key}" != "0" ]; then
Func_import_gnupg_key "${Var_gnupg_import_key}"
else
echo "# ${0##*/} needs a key to import."
exit 1
fi
Run with script_name.sh 'path/to/key' '1' or script_name.sh 'key-id' '1' to import a key and assign a trust value of 1 or edit all values with script_name.sh 'path/to/key' '1' 'hkp://preferred.key.server'
Encryption should now be without complaint but even if it does the following --always-trust option should allow encryption even with complaint.
gpg --no-tty --batch --always-trust -e some_file -r some_recipient -o some_file.gpg
If you wish to see this in action, then check the Travis-CI build logs and how the helper script GnuPG_Gen_Key.sh is used for both generating and importing keys in the same operation... version two of this helper script will be much cleaner and modifiable but it's a good starting point.
This oneliner updates the trustdb with the ownertrust values from STDIN -- by extracting the fingerprint to the format required by --import-ownertrust flag.
This flag, as detailed on gpg man page, should be used In case of a severely damaged trustdb and/or if you have a recent backup of the ownertrust values, you may re-create the trustdb.
gpg --list-keys --fingerprint \
| grep ^pub -A 1 \
| tail -1 \
| tr -d ' ' \
| awk 'BEGIN { FS = "\n" } ; { print $1":6:" }' \
| gpg --import-ownertrust
One way to trust imported gpg keys:
gpg --import <user-id.keyfile>
fpr=`gpg --with-colons --fingerprint <user-id> |awk -F: '$1 == "fpr" {print$10; exit}'`
gpg --export-ownertrust && echo $fpr:6: |gpg --import-ownertrust
here, I assume that you import a key with the <user-id> from <user-id.keyfile>. The second line only extracts fingerprint, you can drop it if you know the fingerprint beforehand.
I think, I figured way to do this.
I used 'gpg --import-ownertrust' to export my trust db into a text file then removed all of my keys from it except public key I needed to push. And then imported my public key and edited owner-trust file on to server. This seems like working.
Now I am having trouble implementing these steps in Kickstart file:-(
With powershell, here is how to trust john.doe#foo.bar (adapted from #tersmitten blog post):
(gpg --fingerprint john.doe#foo.bar | out-string) -match 'fingerprint = (.+)'
$fingerprint = $Matches[1] -replace '\s'
"${fingerprint}:6:" | gpg --import-ownertrust
Note: using cinst gpg4win-vanilla
There is a way to autotrust key using --edit-key, but without getting into interactive shell (so can be automated in script). Below is a sample for windows:
(echo trust &echo 5 &echo y &echo quit) | gpg --command-fd 0 --edit-key your#email.com
Unix based:
echo -e "5\ny\n" | gpg --homedir . --command-fd 0 --expert --edit-key user#exaple.com trust;
For more info read this post. It details if you are creating more than one key.
I used following script for import key:
#!/bin/bash
function usage() {
cat >&2 <<EOF
Usage: $0 path_of_private_key
Example: gpg_import.sh ~/.ssh/my_gpg_private.key
Import gpg key with trust.
EOF
exit 1
}
[[ $# -lt 1 ]] && usage
KEY_PATH=$1
KEY_ID=$(gpg --list-packets ${KEY_PATH}/${GPG_PRIVATE_KEY} | awk '/keyid:/{ print $2 }' | head -1)
gpg --import ${KEY_PATH}/${GPG_PRIVATE_KEY}
(echo trust &echo 5 &echo y &echo quit) | gpg --command-fd 0 --edit-key $KEY_ID
I am using windows with gpgwin4.0.2 installed.
Open the Kleopatra (the GUI) -> Certificates -> Right Click -> Certify. Once the has been certify, this message will not show any.
Try this :
(echo trust &echo 5 &echo y &echo quit &echo save) | gpg --homedir 'gpgDirectory/' --batch --command-fd 0 --edit-key 'youKey'
--homedir : not required
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Is there an easy way to verify that a given private key matches a given public key? I have a few *.puband a few *.key files, and I need to check which go with which.
Again, these are pub/key files, DSA.
I would really prefer a one-liner of some sort...
I found a way that seems to work better for me:
ssh-keygen -y -f <private key file>
That command will output the public key for the given private key, so then just compare the output to each *.pub file.
I always compare an MD5 hash of the modulus using these commands:
Certificate: openssl x509 -noout -modulus -in server.crt | openssl md5
Private Key: openssl rsa -noout -modulus -in server.key | openssl md5
CSR: openssl req -noout -modulus -in server.csr | openssl md5
If the hashes match, then those two files go together.
For DSA keys, use
openssl dsa -pubin -in dsa.pub -modulus -noout
to print the public keys, then
openssl dsa -in dsa.key -modulus -noout
to display the public keys corresponding to a private key, then compare them.
Assuming you have the public keys inside X.509 certificates, and assuming they are RSA keys, then for each public key, do
openssl x509 -in certfile -modulus -noout
For each private key, do
openssl rsa -in keyfile -modulus -noout
Then match the keys by modulus.
The check can be made easier with diff:
diff <(ssh-keygen -y -f $private_key_file) $public_key_file
The only odd thing is that diff says nothing if the files are the same, so you'll only be told if the public and private don't match.
Enter the following command to check if a private key and public key are a matched set (identical) or not a matched set (differ) in $USER/.ssh directory. The cut command prevents the comment at the end of the line in the public key from being compared, allowing only the key to be compared.
ssh-keygen -y -f ~/.ssh/id_rsa | diff -s - <(cut -d ' ' -f 1,2 ~/.ssh/id_rsa.pub)
Output will look like either one of these lines.
Files - and /dev/fd/63 are identical
Files - and /dev/fd/63 differ
I wrote a shell script that users use to check file permission of their ~/.ssh/files and matched key set. It solves my challenges with user incidents setting up ssh. It may help you. https://github.com/BradleyA/docker-security-infrastructure/tree/master/ssh
Note: My previous answer (in Mar 2018) no longer works with the latest releases of openssh. Previous answer: diff -qs <(ssh-keygen -yf ~/.ssh/id_rsa) <(cut -d ' ' -f 1,2 ~/.ssh/id_rsa.pub)
Delete the public keys and generate new ones from the private keys. Keep them in separate directories, or use a naming convention to keep them straight.
If you are in Windows and want use a GUI, with puttygen you can import your private key into it:
Once imported, you can save its public key and compare it to yours.
The easiest is to compare fingerprints as the public and private keys have the same. Visual comparison is pretty easy by putting the two commands on same line:
ssh-keygen -l -f PRIVATE_KEY; ssh-keygen -l -f PUBLIC_KEY
Programmatically, you'll want to ignore the comment portion so
diff -s <(ssh-keygen -l -f PRIVATE_KEY | cut -d' ' -f2) <(ssh-keygen -l -f PUBLIC_KEY | cut -d' ' -f2)
A simple script to check matching of the keys with 3 options:
#!/bin/bash
PRKEY=mysshkey
PUKEY=mysshkey.pub
echo "1. OUTPUT"
diff <( ssh-keygen -y -e -f "${PRKEY}" ) <( ssh-keygen -y -e -f "${PUKEY}")
echo -e "\n"
echo "2. OUTPUT"
diff <( cut -d' ' -f 2 ${PUKEY} ) <( ssh-keygen -y -f "${PRKEY}" | cut -d' ' -f 2)
echo -e "\n"
echo "3. OUTPUT"
DIFF=$(diff <( cut -d' ' -f 2 ${PUKEY} ) <( ssh-keygen -y -f "${PRKEY}" | cut -d' ' -f 2) )
if [ "$DIFF" != "" ]; then
echo "ERROR KEY"
else
echo "TRUE KEY"
fi
If they keys not match you will get an output for output 1 and 2.
If they keys match you get no output.
Output 3 show's a message if keys fit or not.
Encrypt something with the public key, and see which private key decrypts it.
This Code Project article by none other than Jeff Atwood implements a simplified wrapper around the .NET cryptography classes. Assuming these keys were created for use with RSA, use the asymmetric class with your public key to encrypt, and the same with your private key to decrypt.
If it returns nothing, then they match:
cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys
ssh -i $HOME/.ssh/id_rsa localhost
This answer should contain a warning:
https://stackoverflow.com/a/67423640/1312559
WARNING! If the public and private key are in the same directory, the fingerprint is calculated for the public key even though the private key is given as a parameter.
-l' Show fingerprint of specified public key file. Private RSA1 keys are also supported. For RSA and DSA keys ssh-keygen tries to find the matching public key file and prints its fingerprint.
Unfortunately I don't have the reputation to comment.
Just use puttygen and load your private key into it. It offers different options, e.g. exporting the corresponding public key.
I set a passphrase when creating a new SSH key on my laptop. But, as I realise now, this is quite painful when you are trying to commit (Git and SVN) to a remote location over SSH many times in an hour.
One way I can think of is, delete my SSH keys and create new. Is there a way to remove the passphrase, while still keeping the same keys?
Short answer:
$ ssh-keygen -p
This will then prompt you to enter the keyfile location, the old passphrase, and the new passphrase (which can be left blank to have no passphrase).
If you would like to do it all on one line without prompts do:
$ ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-f keyfile]
Important: Beware that when executing commands they will typically be logged in your ~/.bash_history file (or similar) in plain text including all arguments provided (i.e. the passphrases in this case). It is, therefore, is recommended that you use the first option unless you have a specific reason to do otherwise.
Notice though that you can still use -f keyfile without having to specify -P nor -N, and that the keyfile defaults to ~/.ssh/id_rsa, so in many cases, it's not even needed.
You might want to consider using ssh-agent, which can cache the passphrase for a time. The latest versions of gpg-agent also support the protocol that is used by ssh-agent.
$ ssh-keygen -p worked for me
Opened git bash. Pasted : $ ssh-keygen -p
Hit enter for default location.
Enter old passphrase
Enter new passphrase - BLANK
Confirm new passphrase - BLANK
BOOM the pain of entering passphrase for git push was gone.
Thanks!
You might want to add the following to your .bash_profile (or equivalent), which starts ssh-agent on login.
if [ -f ~/.agent.env ] ; then
. ~/.agent.env > /dev/null
if ! kill -0 $SSH_AGENT_PID > /dev/null 2>&1; then
echo "Stale agent file found. Spawning new agent… "
eval `ssh-agent | tee ~/.agent.env`
ssh-add
fi
else
echo "Starting ssh-agent"
eval `ssh-agent | tee ~/.agent.env`
ssh-add
fi
On some Linux distros (Ubuntu, Debian) you can use:
ssh-copy-id -i ~/.ssh/id_dsa.pub username#host
This will copy the generated id to a remote machine and add it to the remote keychain.
You can read more here and here.
To change or remove the passphrase, I often find it simplest to pass in only the p and f flags, then let the system prompt me to supply the passphrases:
ssh-keygen -p -f <name-of-private-key>
For instance:
ssh-keygen -p -f id_rsa
Enter an empty password if you want to remove the passphrase.
A sample run to remove or change a password looks something like this:
ssh-keygen -p -f id_rsa
Enter old passphrase:
Key has comment 'bcuser#pl1909'
Enter new passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved with the new passphrase.
When adding a passphrase to a key that has no passphrase, the run looks something like this:
ssh-keygen -p -f id_rsa
Key has comment 'charlie#elf-path'
Enter new passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved with the new passphrase.
On the Mac you can store the passphrase for your private ssh key in your Keychain, which makes the use of it transparent. If you're logged in, it is available, when you are logged out your root user cannot use it. Removing the passphrase is a bad idea because anyone with the file can use it.
ssh-keygen -K
Add this to ~/.ssh/config
UseKeychain yes
On windows, you can use PuttyGen to load the private key file, remove the passphrase and then overwrite the existing private key file.
In windows for me it kept saying
"id_ed25135: No such file or directory" upon entering above commands. So I went to the folder, copied the path within folder explorer and added "\id_ed25135" at the end.
This is what I ended up typing and worked:
ssh-keygen -p -f C:\Users\john\.ssh\id_ed25135
This worked. Because for some reason, in Cmder the default path was something like this C:\Users\capit/.ssh/id_ed25135 (some were backslashes: "\" and some were forward slashes: "/")
If you have set a passphrase before and is using mac, use the keychain instead, you'll need to enter your passpharase for the last time and that's it
ssh-add --apple-use-keychain ~/.ssh/id_rsa
Enter passphrase for /Users/{{user_name}}/.ssh/id_rsa:
Identity added: /Users/{{user_name}}/.ssh/id_rsa(/Users/{{user_name}}/.ssh/id_rsa)
If you are using Mac
Go to .ssh folder
update config file by adding "UseKeychain yes"