Using: MS Outlook 2003 SP2 (fully patched up) + GPGol 0.9.91

Problem:

A UTF-8 message is sent. It is correctly decrypted. However the displayed text
is mangled. It appears that any non-ASCII parts of the text are interpreted as
another encoding (perhaps Latin-1), not as UTF-8. This problem has also been
seen with EUC-KR encoding. Font issues have been ruled out.

It appears that the problem is caused by Outlook ignoring the charset parameter
in the message's mime-type, and assuming that the charset is some other encoding.

This has been submitted as "Critical" because this problem means that Korean,
Japanese and other foreign language users cannot use GPGol.

To replicate:

Use the following private key (it's a test key):

-----BEGIN PGP PRIVATE KEY BLOCK-----
Version: GnuPG v1.4.7 (GNU/Linux)
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iu3Z

-----END PGP PRIVATE KEY BLOCK-----

Use the following email:

From apache@test.com Thu Jul 26 19:04:15 2007
Received: (from apache@localhost)
by test.com (8.13.8/8.13.8/Submit) id l6QA4FEN013935;
Thu, 26 Jul 2007 19:04:15 +0900
Date: Thu, 26 Jul 2007 19:04:15 +0900
Message-Id: <200707261004.l6QA4FEN013935@test.com>
To: test@localhost.localdomain
Subject: =?utf-8?B?VGVzdCBzdWJqZWN0?=
reply-to: dev_null@this.domain.doesnt.exist
mime-version: 1.0
content-type: multipart/encrypted; protocol="application/pgp-encrypted";
boundary="=_78b3c8b8aaaf76c0c4add"
from: Test Email <noreply@test.com>

--=_78b3c8b8aaaf76c0c4add
Content-Type: application/pgp-encrypted
Content-Transfer-Encoding: 7bit

Version: 1

--=_78b3c8b8aaaf76c0c4add
Content-Transfer-Encoding: 7bit
Content-Type: application/octet-stream; name=encrypted.asc

-----BEGIN PGP MESSAGE-----
Version: GnuPG v1.4.7 (GNU/Linux)
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4BZW

-----END PGP MESSAGE-----

--=_78b3c8b8aaaf76c0c4add--

This email decrypts to:

MIME-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: base64

RW5nbGlzaDogVGhlIHJhaW4gaW4gU3BhaW4gZmFsbHMgbWFpbmx5IG9uIHRoZSBwbGFpbgpKYXBh
bmVzZTog5pel5pys6KqeCktvcmVhbjog7ZWc6rWt7Ja0Ckdlcm1hbjogenVmw6RsbGlnZSBXw7Zy
dGVyIGRldXRzY2g=

The base64 in turn is decoded into the following UTF-8 string (if it doesn't
display right in your browser, switch the encoding to UTF-8):

English: The rain in Spain falls mainly on the plain
Japanese: 日本語
Korean: 한국어
German: zufällige Wörter deutsch

Outlook/GPGol will correctly decrypt the message and apply base64 decoding.
However it will not subsequently consider the decrypted text to be using "UTF-8"
encoding. This means that some of the text is displayed as garbage. This is
what is actually shown (copy/pasted from Outlook's message window)

English: The rain in Spain falls mainly on the plain
Japanese: 日本語
Korean: 한국어
German: zufällige Wörter deutsch