EasyPG Assistant user’s manual
EasyPG Assistant is an Emacs user interface to GNU Privacy Guard (GnuPG, see Top in Using the GNU Privacy Guard).
EasyPG Assistant is a part of the package called EasyPG, an all-in-one GnuPG interface for Emacs. EasyPG also contains the library interface called EasyPG Library.
This file describes EasyPG Assistant 1.0.0.
Copyright © 2007–2016 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover Texts being “A GNU Manual,” and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled “GNU Free Documentation License”.
(a) The FSF’s Back-Cover Text is: “You have the freedom to copy and modify this GNU manual.”
|GnuPG version compatibility|
|GNU Free Documentation License||The license for this documentation.|
EasyPG Assistant provides the following features.
- Key management.
- Cryptographic operations on regions.
- Cryptographic operations on files.
- Dired integration.
- Mail-mode integration.
- Automatic encryption/decryption of *.gpg files.
2 Quick start
EasyPG Assistant commands are prefixed by ‘epa-’. For example,
- To browse your keyring, type M-x epa-list-keys
- To create a cleartext signature of the region, type M-x epa-sign-region
- To encrypt a file, type M-x epa-encrypt-file
EasyPG Assistant provides several cryptographic features which can be integrated into other Emacs functionalities. For example, automatic encryption/decryption of *.gpg files.
This chapter introduces various commands for typical use cases.
|• Key management:|
|• Cryptographic operations on regions:|
|• Cryptographic operations on files:|
|• Dired integration:|
|• Mail-mode integration:|
|• Encrypting/decrypting gpg files:|
3.1 Key management
Probably the first step of using EasyPG Assistant is to browse your keyring. M-x epa-list-keys is corresponding to ‘gpg --list-keys’ from the command line.
The output looks as follows.
u A5B6B2D4B15813FE Daiki Ueno <firstname.lastname@example.org>
A character on the leftmost column indicates the trust level of the key. If it is ‘u’, the key is marked as ultimately trusted. The second column is the key ID, and the rest is the user ID.
You can move over entries by TAB. If you type RET or click button1 on an entry, you will see more detailed information about the key you selected.
u Daiki Ueno <email@example.com> u A5B6B2D4B15813FE 1024bits DSA Created: 2001-10-09 Expires: 2007-09-04 Capabilities: sign certify Fingerprint: 8003 7CD0 0F1A 9400 03CA 50AA A5B6 B2D4 B158 13FE u 4447461B2A9BEA2D 2048bits ELGAMAL_E Created: 2001-10-09 Expires: 2007-09-04 Capabilities: encrypt Fingerprint: 9003 D76B 73B7 4A8A E588 10AF 4447 461B 2A9B EA2D
To browse your private keyring, use M-x epa-list-secret-keys.
In *Keys* buffer, several commands are available. The common use case is to export some keys to a file. To do that, type m to select keys, type o, and then supply the filename.
Below are other commands related to key management. Some of them take a file as input/output, and others take the current region.
- Command: epa-insert-keys keys
Insert selected keys after the point. It will let you select keys before insertion. By default, it will encode keys in the OpenPGP armor format.
- Command: epa-import-keys-region start end
Import keys from the current region between start and end to your keyring.
- Command: epa-import-armor-in-region start end
Import keys in the OpenPGP armor format in the current region between start and end. The difference from
epa-import-armor-in-regionsearches armors in the region and applies
epa-import-keys-regionto each of them.
- Command: epa-delete-keys allow-secret
Delete selected keys. If allow-secret is non-
nil, it also delete the secret keys.
3.2 Cryptographic operations on regions
- Command: epa-decrypt-region start end
Decrypt the current region between start and end. It replaces the region with the decrypted text.
- Command: epa-decrypt-armor-in-region start end
Decrypt OpenPGP armors in the current region between start and end. The difference from
epa-decrypt-armor-in-regionsearches armors in the region and applies
epa-decrypt-regionto each of them. That is, this command does not alter the original text around armors.
- Command: epa-verify-region start end
Verify the current region between start and end. It sends the verification result to the minibuffer or a popup window. It replaces the region with the signed text.
- Command: epa-verify-cleartext-in-region
Verify OpenPGP cleartext blocks in the current region between start and end. The difference from
epa-verify-cleartext-in-regionsearches OpenPGP cleartext blocks in the region and applies
epa-verify-regionto each of them. That is, this command does not alter the original text around OpenPGP cleartext blocks.
- Command: epa-sign-region start end signers type
Sign the current region between start and end. By default, it creates a cleartext signature. If a prefix argument is given, it will let you select signing keys, and then a signature type.
- Command: epa-encrypt-region start end recipients sign signers
Encrypt the current region between start and end. It will let you select recipients. If a prefix argument is given, it will also ask you whether or not to sign the text before encryption and if you answered yes, it will let you select the signing keys.
3.3 Cryptographic operations on files
- Command: epa-decrypt-file file &optional output
Decrypt file. If you do not specify the name output to use for the decrypted file, this function prompts for the value to use.
- Command: epa-sign-file file signers type
Sign file. If a prefix argument is given, it will let you select signing keys, and then a signature type.
3.4 Dired integration
EasyPG Assistant extends Dired Mode for GNU Emacs to allow users to easily do cryptographic operations on files. For example,
M-x dired (mark some files) : e (or M-x epa-dired-do-encrypt) (select recipients by 'm' and click [OK])
The following keys are assigned.
3.5 Mail-mode integration
EasyPG Assistant provides a minor mode
epa-mail-mode to help
user compose inline OpenPGP messages. Inline OpenPGP is a traditional
style of sending signed/encrypted emails by embedding raw OpenPGP
blobs inside a message body, not using modern MIME format.
NOTE: Inline OpenPGP is not recommended and you should consider to use PGP/MIME. See Inline OpenPGP in E-mail is bad, Mm’kay?.
epa-mail-mode is enabled, the following keys are assigned.
You can do it by C-u 1 M-x epa-mail-mode or through the Customize
interface. Try M-x customize-variable epa-global-mail-mode.
- C-c C-e C-d and C-c C-e d
Decrypt OpenPGP armors in the current buffer.
- C-c C-e C-v and C-c C-e v
Verify OpenPGP cleartext signed messages in the current buffer.
- C-c C-e C-s and C-c C-e s
Compose a signed message from the current buffer.
- C-c C-e C-e and C-c C-e e
Compose an encrypted message from the current buffer. By default it tries to build the recipient list from ‘to’, ‘cc’, and ‘bcc’ fields of the mail header. To include your key in the recipient list, use ‘encrypt-to’ option in ~/.gnupg/gpg.conf. This function translates recipient addresses using the
epa-mail-aliaseslist. You can also use that option to ignore specific recipients for encryption purposes.
3.6 Encrypting/decrypting gpg files
By default, every file whose name ends with .gpg will be treated as encrypted. That is, when you open such a file, the decrypted text is inserted in the buffer rather than encrypted one. Similarly, when you save the buffer to a foo.gpg file, encrypted data is written.
The file name pattern for encrypted files can be controlled by epa-file-name-regexp.
You can disable this behavior with M-x epa-file-disable, and then get it back with M-x epa-file-enable.
epa-file will try to use symmetric encryption, aka
password-based encryption. If you want to use public key encryption
instead, do M-x epa-file-select-keys, which pops up the key
- Command: epa-file-select-keys
Select recipient keys to encrypt the currently visiting file with public key encryption.
You can also change the default behavior with the variable epa-file-select-keys.
For frequently visited files, it might be a good idea to tell Emacs
which encryption method should be used through See File Variables in the Emacs Manual. Use the
variable for this.
For example, if you want an Elisp file to be encrypted with a public key associated with an email address ‘firstname.lastname@example.org’, add the following line to the beginning of the file.
;; -*- epa-file-encrypt-to: ("email@example.com") -*-
Instead, if you want the file always (regardless of the value of the
epa-file-select-keys variable) encrypted with symmetric
encryption, change the line as follows.
;; -*- epa-file-encrypt-to: nil -*-
Other variables which control the automatic encryption/decryption behavior are below.
- Variable: epa-file-cache-passphrase-for-symmetric-encryption
nil, cache passphrase for symmetric encryption. The default value is
- Variable: epa-file-inhibit-auto-save
nil, disable auto-saving when opening an encrypted file. The default value is
4 GnuPG version compatibility
As of February 2016, there are three active branches of GnuPG: 2.1, 2.0, and 1.4. All those branches should work flawlessly with Emacs with basic use-cases. They have, however, some incompatible characteristics, which might be visible when used from Emacs.
- The key store format used by GnuPG 2.1 is incompatible with 1.4. That means, a key created with GnuPG 2.1 is not visible with 1.4.
- GnuPG 2.1 uses a fixed address for the Unix domain socket used to
communicate with gpg-agent. The
GPG_AGENT_INFOenvironment variable, which is used by GnuPG 2.0 and 1.4, is ignored. That means, if your system has both GnuPG 2.1 and 1.4, the gpg command from GnuPG 1.4 is not able to use gpg-agent provided by 2.1 (at least out of box).q
- GnuPG 2.1 (2.1.5 or later) has a mechanism to direct the Pinentry password prompt to the Emacs minibuffer1, which would be useful when you use Emacs remotely or from a text-only terminal. That feature is not available in other versions, and more specifically, with 2.0 (as of 2.0.29), there is no way to avoid the graphical prompt.
5 Caching Passphrases
Typing passphrases is a troublesome task if you frequently open and close the same file. GnuPG and EasyPG Assistant provide mechanisms to remember your passphrases. However, the configuration is a bit confusing since it depends on your GnuPG installationSee GnuPG version compatibility, encryption method (symmetric or public key), and whether or not you want to use gpg-agent. Here are some questions:
- Do you use GnuPG version 2.1 or 2.0 instead of GnuPG version 1.4?
- Do you use symmetric encryption rather than public key encryption?
- Do you want to use gpg-agent?
Here are configurations depending on your answers:
|Yes||Yes||Yes||Set up gpg-agent.|
|Yes||Yes||No||You can’t, without gpg-agent.|
|Yes||No||Yes||Set up gpg-agent.|
|Yes||No||No||You can’t, without gpg-agent.|
|No||Yes||Yes||Set up elisp passphrase cache.|
|No||Yes||No||Set up elisp passphrase cache.|
|No||No||Yes||Set up gpg-agent.|
|No||No||No||You can’t, without gpg-agent.|
To set up gpg-agent, follow the instruction in GnuPG manual. see (gnupg)Invoking GPG-AGENT.
To set up elisp passphrase cache, set
See Encrypting/decrypting gpg files.
6 Bug Reports
Bugs and problems with EasyPG Assistant are actively worked on by the Emacs development team. Feature requests and suggestions are also more than welcome. Use M-x report-emacs-bug, see Bugs in Reporting Bugs.
When submitting a bug report, please try to describe in excruciating detail the steps required to reproduce the problem. Also try to collect necessary information to fix the bug, such as:
- the GnuPG version. Send the output of ‘gpg --version’.
- the GnuPG configuration. Send the contents of ~/.gnupg/gpg.conf.
Before reporting the bug, you should set
epg-debug in the
~/.emacs file and repeat the bug. Then, include the contents
of the *epg-debug* buffer. Note that the first letter of the
buffer name is a whitespace.
Appendix A GNU Free Documentation License
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ADDENDUM: How to use this License for your documents
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with the Invariant Sections being list their titles, with the Front-Cover Texts being list, and with the Back-Cover Texts being list.
If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.
If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.
To enable this feature, add ‘allow-emacs-pinentry’ to ~/.gnupg/gpg-agent.conf and let gpg-agent reload the configuration, with: ‘gpgconf --reload gpg-agent’