On 17 May 2018 at 19:49 Ben Harrison <bh@bharrison.it> wrote:

I've successfully implemented the mail_crypt plugin on v2.2.27 and it's working like a champ, but some of our administrative operations require access to Maildir messages in plaintext.

I've found numerous threads detailing help with mail_crypt setup, but none of my research has yielded a method of decrypting the stored messages.

Relevant plugin config:

mail_crypt_curve = prime256v1 mail_crypt_global_private_key = <pirvkey> mail_crypt_global_public_key = <pubkey> mail_crypt_save_version = 2

Method I attempted for manual decryption is listed below:

openssl pkeyutl -derive -inkey mailcrypt.key -peerkey mailcrypt.pub -out shared_secret.bin openssl enc -aes256 -base64 -k $(base64 shared_secret.bin) -d -in test.enc -out test.txt

Openssl reports an error reading the input file, but it isn't permissions related.

I started looking for the encryption/decryption method in the source but figure it's worth seeing if there's some existing methodology I can employ here.

Appreciate any feedback. Thanks,

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*Ben Harrison*

*BHarrison.IT*843.492.4870

The file is not decryptable using openssl enc, since it's not encrypted using that method.

To decrypt the file, you can use this ruby script https://gist.github.com/cmouse/882f2e2a60c1e49b7d343f5a6a2721de

Or you can write one yourself, the mail crypt file format is documented at https://wiki.dovecot.org/Design/Dcrypt

Aki