From: Aki Tuomi <aki.tuomi@open-xchange.com>
Date: Mon, 17 Feb 2025 16:09:58 +0000 (+0200)
Subject: lib-sasl: Support ANONYMOUS mechanism
X-Git-Tag: 2.4.1~121
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=17ed5579027636d7dce2d29042db5b276524be98;p=thirdparty%2Fdovecot%2Fcore.git

lib-sasl: Support ANONYMOUS mechanism
---

diff --git a/src/lib-sasl/Makefile.am b/src/lib-sasl/Makefile.am
index 22a6f290e7..295b8384ef 100644
--- a/src/lib-sasl/Makefile.am
+++ b/src/lib-sasl/Makefile.am
@@ -9,6 +9,7 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)/src/lib-ssl-iostream
 
 libsasl_la_SOURCES = \
+	mech-anonymous.c \
 	mech-external.c \
 	mech-login.c \
 	mech-plain.c \
diff --git a/src/lib-sasl/dsasl-client-private.h b/src/lib-sasl/dsasl-client-private.h
index d1a6174678..8a0cd4f6cb 100644
--- a/src/lib-sasl/dsasl-client-private.h
+++ b/src/lib-sasl/dsasl-client-private.h
@@ -39,6 +39,7 @@ struct dsasl_client_mech {
 	void (*free)(struct dsasl_client *client);
 };
 
+extern const struct dsasl_client_mech dsasl_client_mech_anonymous;
 extern const struct dsasl_client_mech dsasl_client_mech_external;
 extern const struct dsasl_client_mech dsasl_client_mech_login;
 extern const struct dsasl_client_mech dsasl_client_mech_oauthbearer;
diff --git a/src/lib-sasl/dsasl-client.c b/src/lib-sasl/dsasl-client.c
index d1919505d0..d1e38fef3c 100644
--- a/src/lib-sasl/dsasl-client.c
+++ b/src/lib-sasl/dsasl-client.c
@@ -151,7 +151,8 @@ void dsasl_clients_init(void)
 	if (init_refcount++ > 0)
 		return;
 
-	i_array_init(&dsasl_mechanisms, 8);
+	i_array_init(&dsasl_mechanisms, 16);
+	dsasl_client_mech_register(&dsasl_client_mech_anonymous);
 	dsasl_client_mech_register(&dsasl_client_mech_external);
 	dsasl_client_mech_register(&dsasl_client_mech_plain);
 	dsasl_client_mech_register(&dsasl_client_mech_login);
diff --git a/src/lib-sasl/mech-anonymous.c b/src/lib-sasl/mech-anonymous.c
new file mode 100644
index 0000000000..1659085932
--- /dev/null
+++ b/src/lib-sasl/mech-anonymous.c
@@ -0,0 +1,55 @@
+/* Copyright (c) 2025 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "dsasl-client-private.h"
+
+struct anonymous_dsasl_client {
+	struct dsasl_client client;
+	bool output_sent;
+};
+
+static int
+mech_anonymous_input(struct dsasl_client *_client,
+		    const unsigned char *input ATTR_UNUSED, size_t input_len,
+		    const char **error_r)
+{
+	struct anonymous_dsasl_client *client =
+		container_of(_client, struct anonymous_dsasl_client, client);
+
+	if (!client->output_sent) {
+		if (input_len > 0) {
+			*error_r = "Server sent non-empty initial response";
+			return -1;
+		}
+	} else if (input_len > 0) {
+		*error_r = "Server sent non-empty response";
+		return -1;
+	}
+	return 0;
+}
+
+static int
+mech_anonymous_output(struct dsasl_client *_client,
+		     const unsigned char **output_r, size_t *output_len_r,
+		     const char **error_r ATTR_UNUSED)
+{
+	struct anonymous_dsasl_client *client =
+		container_of(_client, struct anonymous_dsasl_client, client);
+
+	const char *authid = client->client.set.authid;
+	if (authid == NULL)
+		authid = "";
+	*output_r = (const unsigned char*)authid;
+	*output_len_r = strlen(authid);
+	client->output_sent = TRUE;
+	return 0;
+}
+
+const struct dsasl_client_mech dsasl_client_mech_anonymous = {
+	.name = "ANONYMOUS",
+	.struct_size = sizeof(struct anonymous_dsasl_client),
+	.flags = DSASL_MECH_SEC_NO_PASSWORD,
+
+	.input = mech_anonymous_input,
+	.output = mech_anonymous_output
+};