For the record: executing gpg2 from the command line is revealing:
gpg: WARNING: message was not integrity protected
gpg: Hint: If this message was created before the year 2003 it is
likely that this message is legitimate. This is because back
then integrity protection was not widely used.
gpg: Use the option '--ignore-mdc-error' to decrypt anyway.
gpg: decryption forced to fail!
The solution is to add `ignore-mdc-error' to ~/.gnupg/gpg.conf.
Óscar Fuentes <o...@wanadoo.es> writes:
> Hello.
>
> Today I noticed that org-crypt is broken on my daily driver.
>
> On a header with the :crypt: tag I invoke org-decrypt-entry, a popup
> dialog asks for the password, I type the password and then the
> minibuffer shows
>
> GPG error: "Decryption failed", ""
>
> The complete error message on *Messages* is
>
> epg--check-error-for-decrypt: GPG error: "Decryption failed", ""
>
> This is a very recent problem. In dpkg.log I see:
>
> 2018-06-12 00:33:00 upgrade gnupg-utils:amd64 2.2.4-1ubuntu1 2.2.4-1ubuntu1.1
>
> 2018-06-12 00:33:05 upgrade gnupg:amd64 2.2.4-1ubuntu1 2.2.4-1ubuntu1.1
>
> I tried the latest org-mode (9.1.13) and Emacs from master branch but
> the problem persists.
>
> $ gpg --version
> gpg (GnuPG) 2.2.4
> libgcrypt 1.8.1
> Copyright (C) 2017 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.
>
> Home: /home/oscar/.gnupg
> Supported algorithms:
> Pubkey: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
> Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
> CAMELLIA128, CAMELLIA192, CAMELLIA256
> Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
> Compression: Uncompressed, ZIP, ZLIB, BZIP2
