=== WP PGP Encrypted Emails === Contributors: meitar Donate link: https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=TJLPJYXHSRBEE&lc=US&item_name=WP%20PGP%20Encrypted%20Emails&item_number=wp-pgp-encrypted-emails&currency_code=USD&bn=PP%2dDonationsBF%3abtn_donate_SM%2egif%3aNonHosted Tags: encryption, email, security, privacy, pgp, gpg, openpgp Requires at least: 4.4 Tested up to: 4.4.2 Stable tag: 0.2.0 License: GPLv3 License URI: https://www.gnu.org/licenses/gpl-3.0.html Encrypts emails WordPress sends using PGP public keys. Provides OpenPGP functions via WordPress plugin API. == Description == WP PGP Encrypted Emails automatically encrypts any email that WordPress sends to your site's admin email address or user email addresses after you give it a copy of the recipient's PGP public key. This protects your user's privacy by ensuring that emails intended for them can be read only by them and them alone. *Donations for this and [my other free software plugins](https://profiles.wordpress.org/meitar#content-plugins) make up a chunk of my income. If you continue to enjoy this plugin, please consider [making a donation](https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=TJLPJYXHSRBEE&lc=US&item_name=WP%20PGP%20Encrypted%20Emails&item_number=wp-pgp-encrypted-emails&currency_code=USD&bn=PP%2dDonationsBF%3abtn_donate_SM%2egif%3aNonHosted). :) Thank you for your support!* The plugin works transparently for *all email* your site generates, and will also encrypt outgoing email generated by other plugins (such as contact form plugins) or the built-in WordPress notification emails. All you have to do is add a PGP public key to the General Settings screen. You can also remove envelope information such as email subject lines, which PGP cannot encrypt. There is no longer any need to pay for the "pro" version of your favorite contact form plugin to get the benefit of email privacy. Additionally, each of your site's users can supply their own, personal public key for their own email address to have WordPress automatically encrypt any email destined for them. (They merely need to update their user profile pages.) Once saved, all future emails WordPress sends to that user will be encrypted with their public key. The encrypted emails can be decrypted by any OpenPGP-compatible mail client, such as [Mailvelope](https://www.mailvelope.com/), [MacGPG](https://gpgtools.org/), or [Enigmail](https://www.enigmail.net/). For more information on reading encrypted emails, generating keys, and other uses for OpenPGP-compatible encrpytion, consult any (or all!) of the following resourceful guides: * [The Electronic Frontier Foundation's Surveillance Self-Defense guide to PGP](https://ssd.eff.org/en/module/introduction-public-key-cryptography-and-pgp) * [RiseUp.net's OpenPGP best practices guide](https://help.riseup.net/en/gpg-best-practices) Additionally, WP PGP Encrypted Emails provides an easy to use API to OpenPGP operations through the familiar [WordPress plugin API](https://codex.wordpress.org/Plugin_API). See the [Other Notes](https://wordpress.org/plugins/wp-pgp-encrypted-emails/other_notes/) page for details. **Security Disclaimer** Security is a process, not a product. Using WP PGP Encrypted Emails does not guarantee that your site's outgoing messages are invulnerable to every attacker, in every possible scenario, at all times. No single security measure, in isolation, can do that. Do not rely solely on this plugin for the security or privacy of your webserver. See the [Frequently Asked Questions](https://wordpress.org/plugins/wp-pgp-encrypted-emails/faq/) for more security advice and for more information about the rationale for this plugin. == Installation == WP PGP Encrypted Emails can be installed automatically from the WordPress plugin repository by searching for "PGP Encrypted Emails" in the "Add new plugin" screen of your WordPres admin site and clicking the "Install now" button. WP PGP Encrypted Emails can also be installed manually by following these instructions: 1. [Download the latest plugin code](https://downloads.wordpress.org/plugin/wp-pgp-encrypted-emails.zip) from the WordPress plugin repository. 1. Upload the unzipped `wp-pgp-encrypted-emails` folder to the `/wp-content/plugins/` directory of your WordPress installation. 1. Activate the plugin through the 'Plugins' menu in WordPress. Once activated, each user who wants to receive encrypted emails must add their PGP public key to their profile. See the [screenshots](https://wordpress.org/plugins/wp-pgp-encrypted-emails/screenshots/) for a brief walkthrough of how to configure WP PGP Encrypted Emails after it is installed. Keep in mind, you will need to have the private key corresponding to the public key you save in your WordPress site, or you will not be able to decrypt the email you receive. To learn more about generating keys and decrypting email, consult one (or more) of the following guides: * [The Electronic Frontier Foundation's Surveillance Self-Defense guide to PGP](https://ssd.eff.org/en/module/introduction-public-key-cryptography-and-pgp) * [RiseUp.net's OpenPGP best practices guide](https://help.riseup.net/en/gpg-best-practices) I have also found the following articles useful, but do not personally vouch for their accuracy: * [Jerzy Gangi's "Best PGP Tutorial for Mac OS X, ever"](http://notes.jerzygangi.com/the-best-pgp-tutorial-for-mac-os-x-ever/) * [DeepDotWeb's Basic Guide to PGP on Linux](https://www.deepdotweb.com/2015/02/17/basic-guide-pgp-linux/) * [BitCoin Not Bombs: Beginner's Guide to PGP](http://www.bitcoinnotbombs.com/beginners-guide-to-pgp/) If you found a good guide to using PGP/GPG that I haven't listed here, please share it in [the WP PGP Encrypted Emails plugin forum](https://wordpress.org/support/plugin/wp-pgp-encrypted-emails#postform). == Frequently Asked Questions== = Is this plugin *really* secure? = Against the NSA? No, probably not. Against a nosy co-worker? Yes, probably. The "realness" of security cannot "really" be measured in abstract, imprecise terms, but rather only based on what real threats you are likely to face and what risks you are vulnerable to if those threats materialize in reality. You have a much better sense of the answers to these things than I do for your situation, because I am not you. Security professionals call this process "threat modeling," and if you are "really" concerned for your security (I encourage you to be!) then learning how to conduct a threat assessment for yourself is a good idea. [Learn more about threat modeling from the EFF's Surveillance Self-Defense Guide](https://ssd.eff.org/en/module/introduction-threat-modeling). = If this plugin isn't secure against the NSA, what good is it? = First of all, not everyone's security needs are the same. (See "threat modeling," discussed in the previous question.) * Against an opportunistic attacker, your security measures merely need to be better than your neighbor's in order to be sufficient to deter attacks. This is "good enough" security for most users of WordPress, especially on shared hosting accounts (which are generally closer to the unsafe side of the security spectrum no matter what plugins you install anyway). * Against a well-resourced, determined adversary who has specifically singled you out, however, what matters is that your ability to secure yourself exceeds your adversary's ability to compromise the specific security precautions you've put in place. Your relative security as compared with your neighbor's doesn't matter. In this case, it is better to do anything and everything you reasonable can do for your protection, even if no specific security measure will be enough on its own. This is known as "[defense in depth](https://en.wikipedia.org/wiki/Defense_in_depth_%28computing%29)" and is analogous to the way a medival castle had a moat that surrounded an outer wall which itself surrounded an inner wall protecting a keep. These concentric rings of security provide redundancy and serve to slow an attacker's intrusion. This plugin can be considered *one* small part of a larger defense-in-depth security approach for your website. Read [Bruce Schneier's "Lessons from the Sony Hack"](https://www.schneier.com/blog/archives/2014/12/lessons_from_th_4.html) for a brief, real-life case study in understanding this important nuance between opportunistic and focused attackers. Further, security is largely a matter of operational practice, not theoretics. If you never use PGP/GPG because the only tools you have access to are not perfect, then you will not have the experience you need to know how to use PGP/GPG when you actually get access to it because you never even practiced using it. By way of analogy, if you want to learn swordfighting but all you have is sticks you picked up in the forest, you are better off picking up those sticks and practicing with them than waiting and not practicing at all until you get your hadns on steel swords. Don't let perfect be the enemy of good. = Why are emails from [other-plugin-here] not being encrypted? = Make sure the emails the other plugin sends are being addressed to an email account that WordPress knows about and that WordPress knows which PGP public key to use when encrypting email destined for that address. More specifically, this means the "TO:" field of the outgoing email needs to match either your WordPress's "admin email" address or the email address of one of your WordPress user accounts, and you need to provide the PGP public key you want WordPress to use when sending email to that address. In many contact form plugins, you can supply an arbitrary email address to send those emails to, but if that email address is not the address of a user on your site, WP PGP Encrypted Emails won't know which PGP public key to use for encryption. As a workaround, simply create an unprivileged ("Subscriber" [role](https://codex.wordpress.org/Roles_and_Capabilities)) new WordPress user account with that email addresss and enter the PGP public key in that user's profile. (Accept the automatically generated password, since you will not need to remember it, as you will never need to log in with that user account.) == Screenshots == 1. Paste the plain text version of your PGP public key into the "PGP Public Key" field in your profile, then click "Save changes" at the bottom of the page. (There is a similar field for the WordPress admin email in the General Settings screen accessible to Administrator users.) 2. If the plugin detects a problem with your PGP public key, you will get a notice like the one shown here. == Change log == = Version 0.2.0 = * [Developer](https://github.com/meitar/wp-pgp-encrypted-emails/issues/5): Added two new filters, `openpgp_key` and `openpgp_encrypt` so plugin developers and theme authors can encrypt arbitrary data, too. = Version 0.1.2 = * [Security](https://github.com/meitar/wp-pgp-encrypted-emails/issues/3): Switch PGP library to [OpenPGP-PGP](https://github.com/singpolyma/openpgp-php). = Version 0.1.1 = * Bugfix: Fix `Fatal error` in cases where the public key is set to `false`. = Version 0.1 = * Initial release. == Other notes == If you like this plugin, **please consider [making a donation](https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=TJLPJYXHSRBEE&lc=US&item_name=WP%20PGP%20Encrypted%20Emails&item_number=wp-pgp-encrypted-emails&currency_code=USD&bn=PP%2dDonationsBF%3abtn_donate_SM%2egif%3aNonHosted) for your use of the plugin**, [purchasing one of Meitar's web development books](http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2Fs%3Fie%3DUTF8%26redirect%3Dtrue%26sort%3Drelevancerank%26search-type%3Dss%26index%3Dbooks%26ref%3Dntt%255Fathr%255Fdp%255Fsr%255F2%26field-author%3DMeitar%2520Moscovitz&tag=maymaydotnet-20&linkCode=ur2&camp=1789&creative=390957) or, better yet, contributing directly to [Meitar's Cyberbusking fund](http://Cyberbusking.org/). (Publishing royalties ain't exactly the lucrative income it used to be, y'know?) Your support is appreciated! = Plugin hooks = This plugin offers additional functionality intended for other plugin developers or theme authors to make use of. This functionality is documented here. == Filters == * `openpgp_key` - Gets a binary OpenPGP public key for use in later PGP operations from an ASCII-armored representation of that key. * Required parameters: * `string` `$key` - The ASCII-armored PGP public key block. Example: Get a key saved as an ASCII string in the WordPress database option `my_plugin_pgp_public_key`. $key = apply_filters('openpgp_key', get_option('my_plugin_pgp_public_key')); * `openpgp_encrypt` - Encrypts data to one or more PGP public keys or passphrases. * Required arguments: * `string` `$data` - Data to encrypt. * `array|string` `$keys` - Passphrases or keys to use to encrypt the data. Examples: Encrypt the content of a blog post. // First, get the PGP public key(s) of the recipient(s) $ascii_key = '-----BEGIN PGP PUBLIC KEY BLOCK----- [...snipped for length...] -----END PGP PUBLIC KEY BLOCK-----'; $encryption_key = apply_filters('openpgp_key', $ascii_key); $encrypted_post = apply_filters('openpgp_encrypt', $post->post_content, $encryption_key); // Now you can safely send or display $encrypted_post anywhere you like and only // those who control the corresponding private key(s) can decrypt it.