EnglishFrenchSpanish

Ad


OnWorks favicon

gpgwrap - Online in the Cloud

Run gpgwrap in OnWorks free hosting provider over Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator

This is the command gpgwrap that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator

PROGRAM:

NAME


gpgwrap - a small wrapper for gpg

SYNOPSIS


gpgwrap -V

gpgwrap -P [-v] [-i] [-a] [-p <file>]

gpgwrap -F [-v] [-i] [-a] [-c] [-p <file>] [-o <name>] [--] <file> [<file> ... ]

gpgwrap [-v] [-i] [-a] [-p <file>] [-o <name>] [--] gpg [gpg options]

DESCRIPTION


The GNU Privacy Guard (gpg) supplies the option --passphrase-fd. This instructs gpg to
read the passphrase from the given file descriptor. Usually this file descriptor is opened
before gpg is executed via execvp(3). Exactly that is what gpgwrap is doing. The
passphrase may be passed to gpgwrap in 4 ways:

* as file path, whereat the passphrase is stored as plain text in the file

* it is piped from another program to the stdin of gpgwrap

* through the GPGWRAP_PASSPHRASE environment variable

* gpgwrap prompts for it

With no precautions the first point undermines the secure infrastructure gpg provides. But
in pure batch oriented environments this may be what you want. Otherwise if you are
willing to enter passphrases once and don't want them to be stored as plain text in a file
gpg-agent is what you are looking for. Another security objection could be the use of the
environment variable GPGWRAP_PASSPHRASE which contains the passphrase and may be read by
other processes of the same user.

OPTIONS


-V, --version
Print out version and exit.

-P, --print
Get the passphrase and print it mangled to stdout.

-F, --file
Read gpg commands from the given files. If <file> is - it is read from stdin.
Exactly one command per line is expected. The given line is handled in the
following way:

* In the first place the passphrase is mangled. This means that unusual characters
are replaced by their backslash escaped octal numbers.

* Secondly the mangled passphrase is stored in the environment variable
GPGWRAP_PASSPHRASE.

* "exec gpgwrap -- " is prepended to each line, before the result is passed as
argument to "sh -c".

-h, --help
Print out usage information.

-v, --verbose
Increase verbosity level.

-i, --interactive
Always prompt for passphrase (ignores -p and the environment variable).

-a, --ask-twice
Ask twice if prompting for a passphrase.

-c, --check-exit-code
While reading gpg commands from a file, gpgwrap ignores per default the exit code
of its child processes. This option enables the check of the exit code. If a child
terminates abnormal or with an exit code not equal 0 gpgwrap stops immediately and
does return with this exit code. See also section BUGS.

-p <file>, --passphrase-file <file>
Read passphrase from <file>. If <file> is - it is read from stdin. The passphrase
is expected to be in plain text. If this option is not given the passphrase will
be taken either from the environment variable GPGWRAP_PASSPHRASE or it will be
prompted on the controlling tty if the environment variable is not set.

-o <name>, --option-name <name>
Specify the name of the "--passphrase-fd" option understood by the program to be
executed. This is useful if you want to use gpgwrap in combination with other
programs than gpg.

LIMITATIONS


The given passphrase is subject to several limitations depending on the way it was passed
to gpgwrap:

* There is a size limitation: the passphrase should be not larger than some
kilobytes (examine the source code for the exact limit).

* gpgwrap allows you to use all characters in a passphrase even \000, but this does
not mean that gpg will accept it. gpg may reject your passphrase or may only read
a part of it, if it contains characters like \012 (in C also known as \n).

* If you set the environment variable GPGWRAP_PASSPHRASE you should take special
care with the backslash character, because gpgwrap uses backslash to escape octal
numbers, (see option -F). Therefore write backslash itself as octal number: \134.

EXAMPLES


1.
gpgwrap -p /path/to/a/secret/file \
gpg -c -z 0 --batch --no-tty \
--cipher-algo blowfish < infile > outfile

Read passphrase from /path/to/a/secret/file and execute gpg to do symmetric
encryption of infile and write it to outfile.

2.
gpgwrap -i -a \
gpg -c -z 0 --batch --no-tty \
--cipher-algo blowfish < infile > outfile

Same as above except that gpgwrap prompts twice for the passphrase.

3.
gpgwrap -F -i - <<EOL
gpg --decrypt --batch --no-tty < "$HOME/infile1" > "$HOME/outfile1"
gpg --decrypt --batch --no-tty < "$HOME/infile2" > "$HOME/outfile2"
gpg --decrypt --batch --no-tty < "$HOME/infile3" > "$HOME/outfile3"
gpg --decrypt --batch --no-tty < "$HOME/infile4" > "$HOME/outfile4"
EOL

gpgwrap prompts for the passphrase and executes four instances of gpg to decrypt
the given files.

4.
GPGWRAP_PASSPHRASE="mysecretpassphrase"
export GPGWRAP_PASSPHRASE
gpgwrap -F -c -v /tmp/cmdfile1 - /tmp/cmdfile2 <<EOL
gpg --decrypt --batch --no-tty < "$HOME/infile1" > "$HOME/outfile1"
gpg --decrypt --batch --no-tty < "$HOME/infile2" > "$HOME/outfile2"
gpg --decrypt --batch --no-tty < "$HOME/infile3" > "$HOME/outfile3"
gpg --decrypt --batch --no-tty < "$HOME/infile4" > "$HOME/outfile4"
EOL

Same as above except that gpgwrap gets the passphrase via the environment
variable, reads commands additionally from other files and checks the exit code of
every gpg instance. This means if one gpg command has a non zero exit code, no
further commands are executed. Furthermore gpgwrap produces verbose output.

5.
GPGWRAP_PASSPHRASE="$(gpgwrap -P -i -a)"
export GPGWRAP_PASSPHRASE

find . -maxdepth 1 -type f |
while read FILE; do
FILE2="$FILE.bz2.gpg"
bzip2 -c "$FILE" |
gpgwrap gpg -c -z 0 --batch --no-tty \
--cipher-algo blowfish > "$FILE2" &&
touch -r "$FILE" "$FILE2" &&
rm -f "$FILE"
done

Read in passphrase, compress all files in the current directory, encrypt them and
keep date from original file.

6.
find . -maxdepth 1 -type f -name '*.bz2.gpg' |
awk '{
printf("gpg --decrypt --batch --no-tty --quiet ");
printf("--no-secmem-warning < %s\n", $0);
}' |
gpgwrap -F -i -c - |
bzip2 -d -c - |
grep -i 'data'

Decrypt all *.bz2.gpg files in the current directory, decompress them and print
out all occurances of data. If you pipe the result to less you get into trouble
because gpgwrap and less try to read from the TTY at the same time. In such a case
it is better to use the environment variable to give the passphrase (the example
above shows how to do this).

7.
GPGWRAP_PASSPHRASE="$(gpgwrap -P -i -a)"
export GPGWRAP_PASSPHRASE

gpgwrap -P |
ssh -C -x -P -l user host "
GPGWRAP_PASSPHRASE=\"\$(cat)\"
...
"

Prompt for a passphrase twice and write it to the GPGWRAP_PASSPHRASE environment
variable.

8.
echo -n "Passphrase: "
stty -echo
read GPGWRAP_PASSPHRASE
echo
stty echo
export GPGWRAP_PASSPHRASE

Another way to prompt manually for the passphrase. It was needed in combination
with older versions of gpgwrap, because they did not upport -P. Be aware that with
this method no automatic conversion to backslash escaped octal numbers takes
place.

9.
echo "mysecretpassphrase" |
gpg --batch --no-tty --passphrase-fd 0 \
--output outfile --decrypt infile

Cheap method to give passphrase to gpg without gpgwrap. Note that you can't use
stdin to pass a file to gpg, because stdin is already used for the passphrase.

10.
gpg --batch --no-tty \
--passphrase-fd 3 3< /path/to/a/secret/file \
< infile > outfile

This is a more advanced method to give the passphrase, it is equivalent to Option
-p of gpgwrap. This example should at least work with the bash.

11.
gpg --batch --no-tty --passphrase-fd 3 \
3< <(echo "mysecretpassphrase") \
< infile > outfile

Like above, but the passphrase is given directly. This example should at least
work with the bash.

Use gpgwrap online using onworks.net services


Free Servers & Workstations

Download Windows & Linux apps

  • 1
    XISMuS
    XISMuS
    ATTENTION: Cumulative update 2.4.3 has
    been released!! The update works for any
    previous 2.x.x version. If upgrading
    from version v1.x.x, please download and
    i...
    Download XISMuS
  • 2
    facetracknoir
    facetracknoir
    Modular headtracking program that
    supports multiple face-trackers, filters
    and game-protocols. Among the trackers
    are the SM FaceAPI, AIC Inertial Head
    Tracker ...
    Download facetracknoir
  • 3
    PHP QR Code
    PHP QR Code
    PHP QR Code is open source (LGPL)
    library for generating QR Code,
    2-dimensional barcode. Based on
    libqrencode C library, provides API for
    creating QR Code barc...
    Download PHP QR Code
  • 4
    Freeciv
    Freeciv
    Freeciv is a free turn-based
    multiplayer strategy game, in which each
    player becomes the leader of a
    civilization, fighting to obtain the
    ultimate goal: to bec...
    Download Freeciv
  • 5
    Cuckoo Sandbox
    Cuckoo Sandbox
    Cuckoo Sandbox uses components to
    monitor the behavior of malware in a
    Sandbox environment; isolated from the
    rest of the system. It offers automated
    analysis o...
    Download Cuckoo Sandbox
  • 6
    LMS-YouTube
    LMS-YouTube
    Play YouTube video on LMS (porting of
    Triode's to YouTbe API v3) This is
    an application that can also be fetched
    from
    https://sourceforge.net/projects/lms-y...
    Download LMS-YouTube
  • More »

Linux commands

  • 1
    a2crd
    a2crd
    a2crd - attempts the conversion of
    lyrics file into chordii input ...
    Run a2crd
  • 2
    a2j
    a2j
    a2j - Wrapper script to simulate
    a2jmidid's non-DBUS behaviour though
    a2jmidid actually being in DBUS mode ...
    Run a2j
  • 3
    coqdoc
    coqdoc
    coqdoc - A documentation tool for the
    Coq proof assistant ...
    Run coqdoc
  • 4
    coqide
    coqide
    coqide - The Coq Proof Assistant
    graphical interface ...
    Run coqide
  • 5
    g.gisenvgrass
    g.gisenvgrass
    g.gisenv - Outputs and modifies the
    user�s current GRASS variable settings.
    Prints all defined GRASS variables if no
    option is given. KEYWORDS: general,
    settin...
    Run g.gisenvgrass
  • 6
    g.guigrass
    g.guigrass
    g.gui - Launches a GRASS graphical user
    interface (GUI) session. Optionally
    updates default user interface settings.
    KEYWORDS: general, GUI, user interface ...
    Run g.guigrass
  • More »

Ad