From b48001d0e96ad798a5ecb8a9f311f2ac75c800bf Mon Sep 17 00:00:00 2001
From: Ken Murchison <murch@fastmail.com>
Date: Tue, 19 Mar 2024 01:50:50 -0400
Subject: [PATCH] imapd.c: add support for JMAPACCESS response code

---
 changes/next/imap_jmapaccess | 19 +++++++++++++++++++
 docsrc/imap/rfc-support.rst  |  8 ++++++--
 imap/imapd.c                 | 11 ++++++++++-
 lib/imapoptions              |  5 +++++
 4 files changed, 40 insertions(+), 3 deletions(-)
 create mode 100644 changes/next/imap_jmapaccess

diff --git a/changes/next/imap_jmapaccess b/changes/next/imap_jmapaccess
new file mode 100644
index 0000000000..1b6a27a1d6
--- /dev/null
+++ b/changes/next/imap_jmapaccess
@@ -0,0 +1,19 @@
+
+Description:
+
+Adds support for IMAP JMAPACCESS response code (draft-ietf-extra-jmapaccess).
+
+
+Config changes:
+
+Adds jmapaccess_url option.
+
+
+Upgrade instructions:
+
+None.
+
+
+GitHub issue:
+
+None.
diff --git a/docsrc/imap/rfc-support.rst b/docsrc/imap/rfc-support.rst
index fb82ccc4ea..416cde263f 100644
--- a/docsrc/imap/rfc-support.rst
+++ b/docsrc/imap/rfc-support.rst
@@ -908,6 +908,10 @@ The following is an inventory of RFCs supported by Cyrus IMAP.
 
     IMAP4 Extension: Message Preview Generation
 
+:rfc:`9042`
+
+    Sieve Email Filtering: Delivery by MAILBOXID
+
 :rfc:`9051`
 
     Internet Message Access Protocol (IMAP) - version 4rev2
@@ -931,9 +935,9 @@ draft-ietf-extra-imap-inprogress
 
    IMAP4 Response Code for Command Progress Notifications
 
-draft-ietf-extra-sieve-mailboxid
+draft-ietf-extra-jmapaccess
 
-    Sieve Email Filtering: delivery by mailboxid
+   The JMAPACCESS Extension for IMAP
 
 draft-ietf-extra-sieve-snooze
 
diff --git a/imap/imapd.c b/imap/imapd.c
index 4220d2e386..6cf61b4cc3 100644
--- a/imap/imapd.c
+++ b/imap/imapd.c
@@ -202,6 +202,7 @@ static int imapd_starttls_done = 0; /* have we done a successful starttls? */
 static int imapd_tls_required = 0; /* is tls required? */
 static void *imapd_tls_comp = NULL; /* TLS compression method, if any */
 static int imapd_compress_done = 0; /* have we done a successful compress? */
+static const char *imapd_jmapaccess_url = NULL;
 static const char *plaintextloginalert = NULL;
 static int ignorequota = 0;
 static int sync_sieve_mailbox_enabled = 0;
@@ -416,7 +417,7 @@ static struct capa_struct base_capabilities[] = {
       { .statep = &imapd_idle_enabled }                       },
     { "IMAPSIEVE=",            0, /* not implemented */ { 0 } }, /* RFC 6785 */
     { "INPROGRESS",            CAPA_POSTAUTH,           { 0 } }, /* draft-ietf-extra-imap-inprogress */
-    { "JMAPACCESS",            0, /* not implemented */ { 0 } }, /* draft-ietf-extra-jmapaccess */
+    { "JMAPACCESS",            0, /* just a respcode */ { 0 } }, /* draft-ietf-extra-jmapaccess */
     { "LANGUAGE",              0, /* not implemented */ { 0 } }, /* RFC 5255 */
     { "LIST-EXTENDED",         CAPA_POSTAUTH,           { 0 } }, /* RFC 5258 */
     { "LIST-METADATA",         CAPA_POSTAUTH,           { 0 } }, /* draft-ietf-extra-imap-list-metadata */
@@ -1076,6 +1077,8 @@ int service_init(int argc, char **argv, char **envp)
     imapd_compress_allowed = 1;
 #endif
 
+    imapd_jmapaccess_url = config_getstring(IMAPOPT_JMAPACCESS_URL);
+
     /* setup for sending IMAP IDLE/NOTIFY notifications */
     if ((imapd_idle_enabled = idle_enabled())) {
         idle_sock = idle_init();
@@ -2918,6 +2921,12 @@ static void authentication_success(const char *tag, int ssf, const char *reply)
     /* authstate already created by mysasl_proxy_policy() */
     imapd_userisadmin = global_authisa(imapd_authstate, IMAPOPT_ADMINS);
 
+    if (imapd_jmapaccess_url) {
+        prot_printf(imapd_out, "* OK [JMAPACCESS \"%s\"] %s\r\n",
+                    imapd_jmapaccess_url,
+                    "This server is also accessible via JMAP, see RFC8620");
+    }
+
     prot_printf(imapd_out, "%s OK", tag);
     if (!ssf) {
         prot_puts(imapd_out, " [CAPABILITY");
diff --git a/lib/imapoptions b/lib/imapoptions
index 000e7bb442..61a7085325 100644
--- a/lib/imapoptions
+++ b/lib/imapoptions
@@ -1230,6 +1230,11 @@ Blank lines and lines beginning with ``#'' are ignored.
    the same has to be done (cyr_dbtool) for each subscription database
    See improved_mboxlist_sort.html.*/
 
+{ "jmapaccess_url", NULL, STRING, "UNRELEASED" }
+/* The JMAP Session URL to advertise to sucessfully authenticated IMAP clients,
+   if the same credentials can be used to authenticate via JMAP
+   (see draft-ietf-extra-jmapaccess). */
+
 { "jmap_emailsearch_db_path", NULL, STRING, "3.1.6", "3.6.0" }
 /* The absolute path to the JMAP email search cache file.  If not
    specified, JMAP Email/query and Email/queryChanges will not