From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Mon, 7 Nov 2022 23:54:38 +0000 (+0100)
Subject: lib-auth: auth-scram-server - Diligently clean key data.
X-Git-Tag: 2.4.0~3125
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e378bcc7e1d0158c4621d46d743978f48bdf0c9d;p=thirdparty%2Fdovecot%2Fcore.git

lib-auth: auth-scram-server - Diligently clean key data.
---

diff --git a/src/lib-auth/auth-scram-server.c b/src/lib-auth/auth-scram-server.c
index 3ed3953aae..7f6b90f6a5 100644
--- a/src/lib-auth/auth-scram-server.c
+++ b/src/lib-auth/auth-scram-server.c
@@ -69,6 +69,9 @@ void auth_scram_server_init(struct auth_scram_server *server_r, pool_t pool,
 void auth_scram_server_deinit(struct auth_scram_server *server)
 {
 	i_assert(server->hash_method != NULL);
+	if (server->proof != NULL)
+		buffer_clear_safe(server->proof);
+	auth_scram_key_data_clear(&server->key_data);
 	pool_unref(&server->pool);
 }
 
@@ -318,6 +321,7 @@ auth_scram_server_verify_credentials(struct auth_scram_server *server)
 	const unsigned char *proof_data = server->proof->data;
 	for (i = 0; i < sizeof(client_signature); i++)
 		client_key[i] = proof_data[i] ^ client_signature[i];
+	buffer_clear_safe(server->proof);
 
 	/* StoredKey       := H(ClientKey) */
 	hash_method_get_digest(hmethod, client_key, sizeof(client_key),
diff --git a/src/lib-auth/auth-scram.c b/src/lib-auth/auth-scram.c
index 50be682e14..a1b5460e8d 100644
--- a/src/lib-auth/auth-scram.c
+++ b/src/lib-auth/auth-scram.c
@@ -1,10 +1,28 @@
 /* Copyright (c) 2022-2023 Dovecot authors, see the included COPYING file */
 
 #include "lib.h"
+#include "safe-memset.h"
 #include "hmac.h"
 
 #include "auth-scram.h"
 
+void auth_scram_key_data_clear(struct auth_scram_key_data *data)
+{
+	if (data->hmethod != NULL) {
+		if (data->stored_key != NULL) {
+			safe_memset(data->stored_key, 0,
+				    data->hmethod->digest_size);
+		}
+		if (data->server_key != NULL) {
+			safe_memset(data->server_key, 0,
+				    data->hmethod->digest_size);
+		}
+	} else {
+		i_assert(data->stored_key == NULL);
+		i_assert(data->server_key == NULL);
+	}
+}
+
 void auth_scram_hi(const struct hash_method *hmethod,
 		   const unsigned char *str, size_t str_size,
 		   const unsigned char *salt, size_t salt_size, unsigned int i,
diff --git a/src/lib-auth/auth-scram.h b/src/lib-auth/auth-scram.h
index ea9194b287..91fff2b8dc 100644
--- a/src/lib-auth/auth-scram.h
+++ b/src/lib-auth/auth-scram.h
@@ -11,6 +11,8 @@ struct auth_scram_key_data {
 	unsigned char *server_key;
 };
 
+void auth_scram_key_data_clear(struct auth_scram_key_data *data);
+
 void auth_scram_hi(const struct hash_method *hmethod,
 		   const unsigned char *str, size_t str_size,
 		   const unsigned char *salt, size_t salt_size, unsigned int i,