Hi to all I was looking at protonmail.com Is possible to implement and end-to-end encryption with dovecot, where server-side there is no private key to decrypt messages? If I understood properly, on protonmail the private key is encrypted with user's password, so that only an user is able to decrypt the mailbox. Anything similiar ?
> On 15 May 2018 at 22:43 Gandalf Corvotempesta <gandalf.corvotempesta at gmail.com> wrote: > > > Hi to all > I was looking at protonmail.com > Is possible to implement and end-to-end encryption with dovecot, where > server-side there is no private key to decrypt messages? >You could probably automate this with sieve and e.g. GnuPG, which would mean that all your mails are encrypted without server having key to decrypt this.> If I understood properly, on protonmail the private key is encrypted with > user's password, so that only an user is able to decrypt the mailbox. > > Anything similiar ?In this case, the server *does* have the private key, even if it's encrypted... =) Dovecot's mail crypt plugin can achieve *similar* thing with mail_crypt_private_password=%{password} (see https://wiki.dovecot.org/Plugins/MailCrypt) But this requires quite good planning, esp. if you are hosting mails, since there is currently no DR feature in dovecot. If you decide to use mail crypt plugin, set it up with private key password, and lose the password, then the mails really are gone. Also worth noting is that, currently, dovecot does not encrypt indexes, which can contain information about your mails. Aki
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Tue, 15 May 2018, Gandalf Corvotempesta wrote:> I was looking at protonmail.com > Is possible to implement and end-to-end encryption with dovecot, where > server-side there is no private key to decrypt messages?Maybe the term "end-to-end encryption" has changed, but usually that means that clients are the "end". Hence, there are no keys on the server. There are some approaches to automatic key discovery and hosting with GnuPG's WKD / WKS.> If I understood properly, on protonmail the private key is encrypted with > user's password, so that only an user is able to decrypt the mailbox.When the encryption takes place on the server, the server admin is able to tinker the process, hence, this is no end-to-end. But, read Aki's fine answer about this. - -- Steffen Kaiser -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEVAwUBWvvNJcQnQQNheMxiAQKGvggAmTSJypn1AnTbarajkEoTWw3q3ciBjDFP Ivv7ENlbXLVVEurx+KWCvP/eO3OnMunUKQjBcTqc9q4fuaDD8GK8CssP1I31oi1i FC4FPOU2U3WGlOjGmgCUsAJuQpdO3kyy28UGWZgmWLFOqDrGtBh3xEGJxOpxI3MH w1Sqhig9M//CBVT+cT5+jcQy2YxuHJODFQj0rhimdRXmK+xSsQioxlUrKpXihw1U n594pw9ogXkZPm5MoEsOahtqxwtXtWbzUqnQZiq3mPDWTtHj0YsSz2HoSAix8oJ/ mGOazhZwLTKYyRLjjTfzmKtT6XMvuHINqXIcrG78t7L9bJwIjdfpnQ==VBMS -----END PGP SIGNATURE-----
Il giorno mer 16 mag 2018 alle ore 06:09 Aki Tuomi <aki.tuomi at dovecot.fi> ha scritto:> You could probably automate this with sieve and e.g. GnuPG, which wouldmean that all your mails are encrypted without server having key to decrypt this. Any guide or sample to look for ?
On 05/16/2018 06:07 AM, Aki Tuomi wrote:>> On 15 May 2018 at 22:43 Gandalf Corvotempesta <gandalf.corvotempesta at gmail.com> wrote: >> Is possible to implement and end-to-end encryption with dovecot, where >> server-side there is no private key to decrypt messages? > > You could probably automate this with sieve and e.g. GnuPG, which would mean > that all your mails are encrypted without server having key to decrypt this.Considering the keywords "dovecot" and "sieve", that would still not be "end to end" and not even "MSA to MX"(-ish) but merely "encrypted storage upon/after final delivery", wouldn't it ... ? FWIW, for auto-encrypting someplace near the MSA, I've used the "GPGPit" tool that's available on the web (and that I've made into an "SMIMEit" myself). The nontrivial problem with that is to retrieve recipients' pubkeys in an even remotely trustworthy manner, of course. Regards, -- Jochen Bern Systemingenieur www.binect.de www.facebook.de/binect -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 4278 bytes Desc: S/MIME Cryptographic Signature URL: <https://dovecot.org/pipermail/dovecot/attachments/20180516/8658631d/attachment-0001.p7s>