I have been trying multiple different ways to decrypt using a Windows batch file. Moving the options around will a) cause the passphrase prompt to pop up or b) the batch file simply failing with a message that the passphrase was not found. There is lots of info online but most of them are old and no longer applicable to the newer version of GPG.
When I do get prompted for the passphrase the files decrypt just fine
Using GPG 2.2.19
Below is the line from the batch file. Can anyone see what is wrong? I understand putting the --password string in the batch-file is not good practice but there only 2 trusted admins on this Windows machine (Win 2012 R2) and we both need the decryption tasks automated.
Batch file:
CD "C:\Program Files (x86)\GnuPG\bin\"
GPG echo PASSPHRASE|gpg --batch --pinentry-mode loopback -o X:\OUTPUTDIRECTORY\FILENAME.CSV --passphrase-fd 0 -d X:\ENCRYPTEDFILEDIRECTORY\FILENAME.gpg
The correct answer is below. Note the quotes, absence of --batch, elimination of echo and PASSPHRASE|gpg. The placement of the options must be exactly like that. I have tested this numerous times and set up windows task scheduler to execute the batch file, everything runs perfect.
gpg --pinentry-mode=loopback --passphrase "YOURPASSPHRASE" -d -o "X:\OUTPUT DIRECTORY\FILENAME.csv" "X:\ENCRYPTEDFILEDIRECTORY\FILENAME.gpg"
Related
I will be receiving PGP encrypted files from a customer through sFTP - I already have a process to automate pulling of files. Once I receive the encrypted file, I'd like to automate decryption.
I created a key pair with GoAnywhere OpenPGP Studio (public key will go to customer). I want to use the private key along with the secret passphrase in a batch file script that will run as a scheduled task in Windows Task Scheduler. This is my script:
gpg --keyring "C:\UserFolder\.openpgpstudio\keys\pubring.pkr" --secret-keyring "C:\UserFolder\.openpgpstudio\keys\secring.skr" --batch --yes --passphrase-fd "secretPassPhrase" -o "D:\FilePath\testPGP.txt" -d "D:\FilePath\testPGP.txt.pgp"
exit
When I try to run my script, there are still some manual steps needed to decrypt files - there are a couple issues I faced:
When executing the batch file, a command prompt window opens with the same script I have in my batch file. For decryption to occur and output a text file, I have to hit Enter. This is not automatic and would cause the scheduled task to get stuck.
Even though I am using the --passphrase-fd option, there are times when I am still prompted for the passphrase - this passphrase popup would also cause the scheduled task to get stuck running.
Is there a way to bypass these two manual steps so that my script is fully automated?
Follow up question: Does the -d option accept wildcard characters so that I can just decrypt any found file with a .pgp extension, and am I able to use the -o option to output a .txt file of the same name as the .pgp file?
--passphrase-fd option should be used with file descriptor (i.e. number like 3, 4, 5 and so on), not the password string. You should use --passphrase option, adding --pinentry-mode=loopback. Currently most likely it works since password is asked via popup and cached.
-d with wildcards doesn't work, however you may use simple script to iterate over all files with pgp extension
I have tectia ssh server in a windows environment.
When I use sftpg3 -B cmd.txt username#host that works fine. The only problem is that it doesnt let me execute files remotely, it only lets me move files. It reads the commands from cmd.txt but since I cant execute anything it ignores the commands.
Well when I do the same thing but use sshg3, it doesnt recognize the -B flag at all.
SSHG3 -B cmd.txt username#host
cmd.txt' is not recognized as an internal or external command,
operable program or batch file.
I've tried putting -B "cmd.txt"
I tried just putting the cmd.txt contents in the same script instead of housing them in cmd.txt and getting rid of -B, but it doesnt run them that way either.
The docs dont have much to go off of. All it says is use -B for batch processing.
Contents of cmd.txt:
D:
cd Library
cd Backup
parseLibrary.cmd
exit
Trying to sshg3 into a host, navigate to a path and run a batch file on that host.
Any ideas?
-B, --batch-mode
Uses batch mode. Fails authentication if it requires user interaction on the terminal.
Using batch mode requires that you have previously saved the server host key on the client and set up a non-interactive method for user authentication (for example, host-based authentication or public-key authentication without a passphrase).
It does use public key authentication, there is no user interaction needed on the terminal.
Noticed this on the docs for sftpg3
-B [ - | batch_file ]
The -B - option enables reading from the standard input. This option is useful when you want to launch processes with sftpg3 and redirect the stdin pipes.
By defining the name of a batch_file as an attribute, you can execute SFTP commands from the given file in batch mode. The file can contain any allowed SFTP commands. For a description of the commands, see the section called “Commands”.
Using batch mode requires that you have previously saved the server host key on the client and set up a non-interactive method for user authentication (for example, host-based authentication or public-key authentication without a passphrase).
I'm guessing batch file is different than batch mode?
*I figured it out. You have to use the -B flag for every command you want to execute.
I figured it out. You have to use the -B flag for every command you want to execute.
sshg3 user#host -B dir -B ipconfig -B etc.cmd
Having read this question and my answer there, I would like to do a similar thing on Windows.
My Linux solution is this:
#!/bin/bash
[[ $1 =~ password: ]] && cat || SSH_ASKPASS="$0" DISPLAY=nothing:0 exec setsid "$#"
How can I do a similar thing on Windows, something I can use like this from a Windows Command Prompt or batch file:
C:> echo password | pass ssh user#host ...
Points to note:
ssh here was installed using the free edition of crwsync. It uses Cygwin DLLs but does not require a Cygwin install.
the solution should not require further dependencies: it work from a typical Windows Command Prompt or batch file.
I'm looking for an answer to the above, even if the answer is "it can't be done". I know I can use keys (and their relative merits), or other tools such as Python/Paramiko, PuTTY plink, and so-on. I know I can do it in a Cygwin environment. I don't want to do those things... I need to do it from a plain old Windows command prompt or batch file without incurring additional dependencies because, if this is possible, it will reduce existing dependencies.
Here is what I have so far:
#echo off
echo.%1 | findstr /C:"password">nul
if errorlevel 1 (
set SSH_ASKPASS="%0"
set DISPLAY="nothing:0"
%*
) else (
findstr "^"
)
The idea is to save that as, say pass.bat and use it like this:
C:> echo password | pass.bat ssh user#host ...
What happens is that the SSH session is launched but ssh still interactively prompts for the password. I think that, in theory, the script is ok becuse the below works:
C:> echo mypassword | pass.bat pass.bat "password"
mypassword
As far as I understand, the underlying Cygwin DLLs should see the Windows environment so the setting of SSH_ASKPASS should propagate into ssh.
I think the problem is that ssh is connected to the terminal. According to man ssh, If ssh needs a passphrase, it will read the passphrase from the current terminal if it was run from a terminal. This is why I use setsid in the Linux example. I think a way to detach the process from the terminal in Windows is required but I am not sure there is one (I did try start /B).
So I'm stuck - I don't know enough about scripting windows to know what should work. Any solution that uses native windows techniques (i.e. batch or perhaps powershell) and does not require anything not available on a vanilla Windows would be welcome.
The solution will be used by a cross platform application that I am working on that needs to use SSH to interact with an external service. The current prototype version is Python and is aready wired up to launch ssh as a subprocess. The Linux version already uses the above method so I would like a Windows solution that does not require reworking of the application.
SSH will never read password from stdin. I would give a shot sshpass utility, which is quite standard for this task. The other common solution is using expect script (which should work the same way on the Cygwin as on Linux).
I would like to use GnuPG´s decrypt command without any user interation. The script's --passphrase-fd argument seems exactly what I need. But I don't know how it works - haven't found examples.
Could anyone give me an example of such a command, on both Windows and UNIX environments?
(FYI, I'm using GnuPG 2).
Thanks already :)
In order to use the gpg option --passphrase-fd in GnuPG v2, you must specify the --batch parameter. I will first explain how --passphrase-fd works, and then get to the examples.
--passphrase-fd tells GnuPG which file descriptor (-fd) to expect the passphrase to come from. The standard file descriptors are STDIN (0), STDOUT (1) and STDERR (2). For the context of this question, you would normally only be concerned about STDIN (0).
You didn't specify where you want the passphrase to come from, so I will demonstrate the usage of STDIN (standard in) in a variety of ways.
--passphrase-fd 0 tells GnuPG to retrieve the passphrase from input into the current shell; so for example if you want GnuPG to get the passphrase data in the very next line of console input, the command and output would be like so:
gpg2 --batch --passphrase-fd 0 --armor --decrypt /path/to/encrypted_file.pgp
<next line of input is passphrase followed by hitting enter>
gpg: encrypted with 1024-bit RSA key, ID EC18C175, created 2013-10-26
"testkey4321 (4321) <test#4321.com>"
this is a test... this is only a test...
In the above example, the passphrase was provided via file descriptor 0 (STDIN) - which we provided by entering it on the shells current standard input.
In the next example, we will tell GnuPG to retrieve the passphrase from input into the current shell that is actually the output of another command (echo, in this case, which merely "echos" what you tell it to):
echo "mypassphrase" | gpg2 --batch --passphrase-fd 0 --armor --decrypt /path/to/encrypted_file.pgp
gpg: encrypted with 1024-bit RSA key, ID EC18C175, created 2013-10-26
"testkey4321 (4321) <test#4321.com>"
this is a test... this is only a test...
Another example that dumps the contents of a file that contains the passphrase to STDIN -
cat /path/to/file_with_passphrase | gpg2 --batch --passphrase-fd 0 --armor --decrypt /path/to/encrypted_file.pgp
gpg: encrypted with 1024-bit RSA key, ID EC18C175, created 2013-10-26
"testkey4321 (4321) <test#4321.com>"
this is a test... this is only a test...
In summary, --passphrase-fd just tells GnuPG that you want to feed it the requisite passphrase via a standard file descriptor; the difference between GnuPG v2 and GnuPG is merely the --batch parameter.
The above examples should work the same in Windows and *nix environments, with the only difference being that in Windows - depending on your configuration and version - you will have to replace cat with type in order to dump the contents of a file to STDIN.
kylehuff's answer still wouldn't work for me, with gpupg still popping up a password prompt.
According to https://wiki.archlinux.org/index.php/GnuPG#Unattended_passphrase with gnupg version 2.1.0 and higher, you need to do additional steps to support --passphrase-fd
First, edit the gpg-agent configuration to allow loopback pinentry mode:
~/.gnupg/gpg-agent.conf
allow-loopback-pinentry
Restart the gpg-agent process if it is running to let the change take effect.
Second, either the application needs to be updated to include a commandline parameter to use loopback mode like so:
$ gpg --pinentry-mode loopback ...
Using GPG4win/gpg 2.2.3: to use the passphrase-fd 0 and bypass the prompt, I can confirm that the following works:
--pinentry-mode loopback
As I've had to recently figure this out myself I thought it might be worth chiming in.
The answer by kylehuff is very good if you're decryping files, however, if you've need of input/output redirection, such as piping, here's an example of using a non-0 file descriptor to pass the passphrase.
#!/usr/bin/env bash
# Set some variables for easy modding
Var_fd='9'
Var_pass_location="/path/to/passphrase.file"
Var_gpg_decrypt_opts="--passphrase-fd ${Var_fd} --decrypt"
Var_output_location="out.txt"
Arr_string=( "$#" )
# Open file descriptor and shove the passphrase file into it
exec ${Var_fd}<${Var_pass_location}
# Pipe input array though gpg and append to output file
cat <<<"${Arr_string[*]}" | $(which gpg) ${Var_gpg_decrypt_opts} >> ${Var_output_location}
# Do not forget to close the file descriptor
exec ${Var_fd}>&-
Do be warned, outside of special use cases, that saving your private keys passphrase is generally seen as a bad idea or bad security practice. -Also please don't forget to close the descriptor when finished so that your passphrase isn't accessible via that method anymore.- Often I've seen advised in these use cases to use specifically non-passphrase protected keys but that's totally your choose. If you like the above code then you may want to also checkout the script I debugged for key generation either unattended or attended because it covers even less commonly used gpg file descriptor options.
Edits/updates
So I've been debugging the bulk decryption operations and have evidence to show that file descriptors seem to close automatically or perhaps it's auto closed by GnuPG. Check build 152 all the way at the bottom of the raw logs, just before diff checks, you'll find that the first block of encrypted data ate the passphrase leaving the next two blocks of data without a valid passphrase. The related scripts in this operation are ; first the script_decrypt.sh build script sets the test key's passphrase to file descriptor 9 as shown in above examples, then the Helper script is called such that it'll make use of that file descriptor... it's a funky use case but the moral of the story seems to be that what ever bulk decryption operations you plan to implement with GnuPG file descriptors will likely need to follow the steps outlined above as a whole function to properly have the file descriptors reopened. I'll be rewriting the helper script over the next few pushes so check the Travis-CI build logs greater than 152 to find if I've a solution to where file descriptors get closed...
... so that only took two tries to get things working, see the difference in build 154 both the encrypted file and raw input log match. As hypothesised the file descriptors get dumped after first usage by either GnuPG or a sub shell, thus the passphrase needs to be assigned before every decrypt command for bulk decryption to happen.
Hope this was valuable to y'all.
I want to install a software library (SWIG) on a list of computers (Jenkins nodes). I'm using the following script to automate this somewhat:
NODES="10.8.255.70 10.8.255.85 10.8.255.88 10.8.255.86 10.8.255.65 10.8.255.64 10.8.255.97 10.8.255.69"
for node in $NODES; do
scp InstallSWIG.sh root#$node:/root/InstallSWIG.sh
ssh root#$node sh InstallSWIG.sh
done
This way it's automated, except for the password request that occur for both the scp and ssh commands.
Is there a way to enter the passwords programmatically?
Security is not an issue. I’m looking for solutions that don’t involve SSH keys.
Here’s an expect example that sshs in to Stripe’s Capture The Flag server and enters the password automatically.
expect <<< 'spawn ssh level01#ctf.stri.pe; expect "password:"; send "e9gx26YEb2\r";'
With SSH the right way to do it is to use keys instead.
# ssh-keygen
and then copy the *~/.ssh/id_rsa.pub* file to the remote machine (root#$node) into the remote user's .ssh/authorized_keys file.
You can perform the task using empty, a small utility from sourceforge. It's similar to expect but probably more convenient in this case. Once you have installed it, your first scp will be accomplished by following two commands:
./empty -f scp InstallSWIG.sh root#$node:/root/InstallSWIG.sh
echo YOUR_SECRET_PASSWORD | ./empty -s -c
The first one starts your command in the background, tricking it into thinking it's running in interactive mode on a terminal. The other one sends it data from stdin. Of course, putting your password anywhere on command line is risky due to shell history being preserved, users being able to see it in ps results etc. Not secure either, but a bit better thing would be to store the password in a file and redirect the second command's input from that file instead of using echo and a pipe.
After copying to the server, you can run the script in a similar manner:
./empty -f ssh root#$node sh InstallSWIG.sh
echo YOUR_SECRET_PASSWORD | ./empty -s -c
You could look into setting up passwordless ssh keys for that. Establishing Batch Mode Connections between OpenSSH and SSH2 is a starting point, you'll find lots of information on this topic on the web.
Wes' answer is the correct one but if you're keen on something dirty and slow, you can use expect to automate this.