--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/backend/plugins/plugin_sec_gre_encrypter_openpgp.py	Mon Jan 13 01:23:22 2025 +0100
@@ -0,0 +1,108 @@
+#!/usr/bin/env python3
+
+# Libervia plugin
+# Copyright (C) 2009-2025 Jérôme Poisson (goffi@goffi.org)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import base64
+from typing import Final, TYPE_CHECKING, cast
+
+from twisted.words.protocols.jabber import jid
+from twisted.words.protocols.jabber.xmlstream import XMPPHandler
+from twisted.words.xish import domish
+from wokkel import data_form, disco, iwokkel
+from zope.interface import implementer
+
+from libervia.backend.core import exceptions
+from libervia.backend.core.constants import Const as C
+from libervia.backend.core.core_types import SatXMPPEntity
+from libervia.backend.core.i18n import _
+from libervia.backend.core.log import getLogger
+from libervia.backend.plugins import plugin_xep_0373
+from .plugin_exp_gre import Encrypter
+
+if TYPE_CHECKING:
+    from libervia.backend.core.main import LiberviaBackend
+
+log = getLogger(__name__)
+
+
+PLUGIN_INFO = {
+    C.PI_NAME: "GRE Encrypter: OpenPGP",
+    C.PI_IMPORT_NAME: "GRE-OpenPGP",
+    C.PI_TYPE: "XEP",
+    C.PI_MODES: C.PLUG_MODE_BOTH,
+    C.PI_PROTOCOLS: [],
+    C.PI_DEPENDENCIES: [
+        "GRE",
+    ],
+    C.PI_RECOMMENDATIONS: [],
+    C.PI_MAIN: "GREEncrypterOpenPGP",
+    C.PI_HANDLER: "yes",
+    C.PI_DESCRIPTION: _("Handle MIME formatting for Gateway Relayed Encryption."),
+}
+
+NS_GRE_OPENPGP: Final = "urn:xmpp:gre:encrypter:openpgp:0"
+
+
+class GREEncrypterOpenPGP(Encrypter):
+    name = "openpgp"
+    namespace = NS_GRE_OPENPGP
+
+    def __init__(self, host: "LiberviaBackend") -> None:
+        log.info(f"plugin {PLUGIN_INFO[C.PI_NAME]!r} initialization")
+        super().__init__(host)
+        host.register_namespace("gre-openpgp", NS_GRE_OPENPGP)
+
+    def get_handler(self, client: SatXMPPEntity) -> XMPPHandler:
+        return GREMIMEHandler(self)
+
+    async def encrypt(
+        self,
+        client: SatXMPPEntity,
+        recipient_id: str,
+        message_elt: domish.Element,
+        formatted_payload: bytes,
+        encryption_data_form: data_form.Form,
+    ) -> str:
+        gpg_provider = plugin_xep_0373.get_gpg_provider(self.host, client)
+        public_keys = gpg_provider.list_public_keys(recipient_id)
+        if not public_keys:
+            raise exceptions.NotFound(
+                f"No public keys found for {recipient_id!r}, we can't encrypt."
+            )
+        encrypted_data = gpg_provider.encrypt(
+            formatted_payload, public_keys
+        )
+        return base64.b64encode(encrypted_data).decode("ASCII")
+
+
+@implementer(iwokkel.IDisco)
+class GREMIMEHandler(XMPPHandler):
+
+    def __init__(self, plugin_parent):
+        self.plugin_parent = plugin_parent
+
+    def getDiscoInfo(
+        self, requestor: jid.JID, target: jid.JID, nodeIdentifier: str = ""
+    ) -> list[disco.DiscoFeature]:
+        return [
+            disco.DiscoFeature(NS_GRE_OPENPGP),
+        ]
+
+    def getDiscoItems(
+        self, requestor: jid.JID, target: jid.JID, nodeIdentifier: str = ""
+    ) -> list[disco.DiscoItems]:
+        return []