14223 Add change key zfs channel program

Portions contributed by: Alex Wilson <alex@cooperi.net>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Mike Zeller <mike.zeller@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Approved by: Dan McDonald <danmcd@joyent.com>

6 files changed, 278 insertions, 7 deletions

diff --git a/usr/src/uts/common/fs/zfs/dsl_crypt.c b/usr/src/uts/common/fs/zfs/dsl_crypt.c
index cb412151e7..ed98740f1d 100644
--- a/usr/src/uts/common/fs/zfs/dsl_crypt.c
+++ b/usr/src/uts/common/fs/zfs/dsl_crypt.c
@@ -1220,12 +1220,7 @@ dsl_crypto_key_sync(dsl_crypto_key_t *dck, dmu_tx_t *tx)
 	    tx);
 }
 
-typedef struct spa_keystore_change_key_args {
-	const char *skcka_dsname;
-	dsl_crypto_params_t *skcka_cp;
-} spa_keystore_change_key_args_t;
-
-static int
+int
 spa_keystore_change_key_check(void *arg, dmu_tx_t *tx)
 {
 	int ret;
@@ -1501,7 +1496,7 @@ spa_keystore_change_key_sync_impl(uint64_t rddobj, uint64_t ddobj,
 	dsl_dir_rele(dd, FTAG);
 }
 
-static void
+void
 spa_keystore_change_key_sync(void *arg, dmu_tx_t *tx)
 {
 	dsl_dataset_t *ds;
diff --git a/usr/src/uts/common/fs/zfs/sys/dsl_crypt.h b/usr/src/uts/common/fs/zfs/sys/dsl_crypt.h
index cf19665aae..5b7c1a9510 100644
--- a/usr/src/uts/common/fs/zfs/sys/dsl_crypt.h
+++ b/usr/src/uts/common/fs/zfs/sys/dsl_crypt.h
@@ -164,6 +164,11 @@ typedef struct spa_keystore {
 	avl_tree_t sk_wkeys;
 } spa_keystore_t;
 
+typedef struct spa_keystore_change_key_args {
+	const char *skcka_dsname;
+	dsl_crypto_params_t *skcka_cp;
+} spa_keystore_change_key_args_t;
+
 int dsl_crypto_params_create_nvlist(dcp_cmd_t cmd, nvlist_t *props,
     nvlist_t *crypto_args, dsl_crypto_params_t **dcp_out);
 void dsl_crypto_params_free(dsl_crypto_params_t *dcp, boolean_t unload);
@@ -199,6 +204,8 @@ int dsl_crypto_recv_raw(const char *poolname, uint64_t dsobj, uint64_t fromobj,
     dmu_objset_type_t ostype, nvlist_t *nvl, boolean_t do_key);
 
 int spa_keystore_change_key(const char *dsname, dsl_crypto_params_t *dcp);
+int spa_keystore_change_key_check(void *arg, dmu_tx_t *tx);
+void spa_keystore_change_key_sync(void *arg, dmu_tx_t *tx);
 int dsl_dir_rename_crypt_check(dsl_dir_t *dd, dsl_dir_t *newparent);
 int dsl_dataset_promote_crypt_check(dsl_dir_t *target, dsl_dir_t *origin);
 void dsl_dataset_promote_crypt_sync(dsl_dir_t *target, dsl_dir_t *origin,
diff --git a/usr/src/uts/common/fs/zfs/sys/zcp_change_key.h b/usr/src/uts/common/fs/zfs/sys/zcp_change_key.h
new file mode 100644
index 0000000000..fea520455f
--- /dev/null
+++ b/usr/src/uts/common/fs/zfs/sys/zcp_change_key.h
@@ -0,0 +1,41 @@
+/*
+ * CDDL HEADER START
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2020 Joyent, Inc.
+ */
+
+#ifndef _SYS_ZCP_CHANGE_KEY_H
+#define	_SYS_ZCP_CHANGE_KEY_H
+
+#include <sys/types.h>
+#include <sys/dmu.h>
+#include <sys/dsl_crypt.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void zcp_synctask_change_key_cleanup(void *arg);
+int zcp_synctask_change_key_check(void *arg, dmu_tx_t *tx);
+void zcp_synctask_change_key_sync(void *arg, dmu_tx_t *tx);
+int zcp_synctask_change_key_create_params(const char *key, size_t keylen,
+    zfs_keyformat_t keyformat, dsl_crypto_params_t **dcpp);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SYS_ZCP_CHANGE_KEY_H */
diff --git a/usr/src/uts/common/fs/zfs/zcp_change_key.c b/usr/src/uts/common/fs/zfs/zcp_change_key.c
new file mode 100644
index 0000000000..be16a8d5c6
--- /dev/null
+++ b/usr/src/uts/common/fs/zfs/zcp_change_key.c
@@ -0,0 +1,144 @@
+/*
+ * CDDL HEADER START
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2020 Joyent, Inc.
+ */
+
+#include <sys/ctype.h>
+#include <sys/zcp.h>
+#include <sys/zcp_change_key.h>
+
+static uint8_t
+hexval(char c)
+{
+	if (c >= '0' && c <= '9')
+		return (c - '0');
+	else if (c >= 'a' && c <= 'f')
+		return (c - 'a' + 10);
+	else if (c >= 'A' && c <= 'F')
+		return (c - 'A' + 10);
+
+	panic("invalid hex value");
+}
+
+static int
+hex_to_raw(const char *key, uint8_t *buf, size_t buflen)
+{
+	uint8_t *p;
+	size_t srclen = strlen(key);
+	size_t i;
+
+	if (buflen * 2 != srclen)
+		return (SET_ERROR(EINVAL));
+
+	for (i = 0, p = buf; i < srclen; i += 2, p++) {
+		if (!isxdigit(key[i]) || !isxdigit(key[i + 1]))
+			return (SET_ERROR(EINVAL));
+
+		*p = hexval(key[i]) << 4 | hexval(key[i + 1]);
+	}
+
+	return (0);
+}
+
+int
+zcp_synctask_change_key_create_params(const char *key, size_t keylen,
+    zfs_keyformat_t keyformat, dsl_crypto_params_t **dcpp)
+{
+	nvlist_t *args = fnvlist_alloc();
+	nvlist_t *hidden_args = fnvlist_alloc();
+	uint8_t rawkey[WRAPPING_KEY_LEN];
+	uint_t rawlen = 0;
+	int err = 0;
+
+	/*
+	 * Currently, only raw and hex keys are supported in channel
+	 * programs (there is no pbkdf2 support in the kernel to convert
+	 * a passphrase).
+	 */
+	switch (keyformat) {
+	case ZFS_KEYFORMAT_RAW:
+		/*
+		 * dsl_crypto_params_create_nvlist() also verifies the
+		 * raw key is WRAPPING_KEY_LEN bytes, so this is
+		 * _almost_ redundant -- however we still want to
+		 * guarantee we won't overflow rawkey when copying
+		 * the contents over.
+		 */
+		if (keylen != WRAPPING_KEY_LEN) {
+			err = SET_ERROR(EINVAL);
+			goto done;
+		}
+
+		bcopy(key, rawkey, keylen);
+		rawlen = keylen;
+		break;
+	case ZFS_KEYFORMAT_HEX:
+		/*
+		 * hex_to_raw() will reject any input that doesn't exactly
+		 * fit into rawkey
+		 */
+		err = hex_to_raw(key, rawkey, sizeof (rawkey));
+		if (err != 0)
+			goto done;
+		rawlen = sizeof (rawkey);
+		break;
+	default:
+		err = SET_ERROR(EINVAL);
+		goto done;
+	}
+
+	fnvlist_add_uint64(args, zfs_prop_to_name(ZFS_PROP_KEYFORMAT),
+	    (uint64_t)keyformat);
+	fnvlist_add_uint8_array(hidden_args, "wkeydata", rawkey, rawlen);
+
+	err = dsl_crypto_params_create_nvlist(DCP_CMD_NEW_KEY, args,
+	    hidden_args, dcpp);
+
+done:
+	fnvlist_free(args);
+	fnvlist_free(hidden_args);
+	bzero(rawkey, sizeof (rawkey));
+
+	return (err);
+}
+
+void
+zcp_synctask_change_key_cleanup(void *arg)
+{
+	spa_keystore_change_key_args_t *skcka = arg;
+
+	dsl_crypto_params_free(skcka->skcka_cp, B_TRUE);
+}
+
+int
+zcp_synctask_change_key_check(void *arg, dmu_tx_t *tx)
+{
+	/*
+	 * zcp_synctask_change_key_create_params() already validates that
+	 * the new key is in an acceptable format and size for a channel
+	 * program. Any future channel program specific checks would go here.
+	 * For now, we just perform all the same checks done for
+	 * 'zfs change-key' by calling spa_keystore_change_key_check().
+	 */
+	return (spa_keystore_change_key_check(arg, tx));
+}
+
+void
+zcp_synctask_change_key_sync(void *arg, dmu_tx_t *tx)
+{
+	spa_keystore_change_key_sync(arg, tx);
+}
diff --git a/usr/src/uts/common/fs/zfs/zcp_synctask.c b/usr/src/uts/common/fs/zfs/zcp_synctask.c
index 09af25c1c9..9a1dceb044 100644
--- a/usr/src/uts/common/fs/zfs/zcp_synctask.c
+++ b/usr/src/uts/common/fs/zfs/zcp_synctask.c
@@ -23,6 +23,8 @@
 
 #include <sys/zcp.h>
 #include <sys/zcp_set.h>
+#include <sys/zcp_change_key.h>
+#include <sys/dsl_crypt.h>
 #include <sys/dsl_dir.h>
 #include <sys/dsl_pool.h>
 #include <sys/dsl_prop.h>
@@ -399,6 +401,74 @@ zcp_synctask_set_prop(lua_State *state, boolean_t sync, nvlist_t *err_details)
 	return (err);
 }
 
+static int zcp_synctask_change_key(lua_State *, boolean_t, nvlist_t *);
+static zcp_synctask_info_t zcp_synctask_change_key_info = {
+	.name = "change_key",
+	.func = zcp_synctask_change_key,
+	.pargs = {
+		{ .za_name = "dataset", .za_lua_type = LUA_TSTRING },
+		{ .za_name = "key", .za_lua_type = LUA_TSTRING },
+		{ .za_name = "format", .za_lua_type = LUA_TSTRING },
+		{ NULL, 0 },
+	},
+	.kwargs = {
+		{ NULL, 0 }
+	},
+	.space_check = ZFS_SPACE_CHECK_RESERVED,
+	/*
+	 * This is the same value that is used when zfs change-key is run.
+	 * See spa_keystore_change_key() in dsl_crypt.c
+	 */
+	.blocks_modified = 15
+};
+
+static int
+zcp_synctask_change_key(lua_State *state, boolean_t sync, nvlist_t *err_details)
+{
+	int err;
+	spa_keystore_change_key_args_t skcka = { 0 };
+	dsl_crypto_params_t *dcp = NULL;
+	const char *dsname;
+	const char *key;
+	const char *format;
+	size_t keylen;
+	uint64_t keyformat;
+
+	dsname = lua_tostring(state, 1);
+
+	/*
+	 * The key may be raw key, which could contain NUL within it.
+	 * Use lua_tolstring() instead of lua_tostring() to obtain the length.
+	 */
+	key = lua_tolstring(state, 2, &keylen);
+
+	format = lua_tostring(state, 3);
+
+	if (zfs_prop_string_to_index(ZFS_PROP_KEYFORMAT, format,
+	    &keyformat) != 0)
+		return (SET_ERROR(EINVAL));
+
+	err = zcp_synctask_change_key_create_params(key, keylen, keyformat,
+	    &dcp);
+	if (err != 0)
+		goto done;
+
+	skcka.skcka_dsname = dsname;
+	skcka.skcka_cp = dcp;
+
+	zcp_cleanup_handler_t *zch = zcp_register_cleanup(state,
+	    (zcp_cleanup_t *)&zcp_synctask_change_key_cleanup, &skcka);
+
+	err = zcp_sync_task(state, zcp_synctask_change_key_check,
+	    zcp_synctask_change_key_sync, &skcka, sync, dsname);
+
+	zcp_deregister_cleanup(state, zch);
+
+done:
+	dsl_crypto_params_free(dcp, (err != 0 || !sync) ? B_TRUE : B_FALSE);
+	return (err);
+}
+
 static int
 zcp_synctask_wrapper(lua_State *state)
 {
@@ -468,6 +538,7 @@ zcp_load_synctask_lib(lua_State *state, boolean_t sync)
 		&zcp_synctask_snapshot_info,
 		&zcp_synctask_inherit_prop_info,
 		&zcp_synctask_set_prop_info,
+		&zcp_synctask_change_key_info,
 		NULL
 	};
 
diff --git a/usr/src/uts/common/fs/zfs/zfs_ioctl.c b/usr/src/uts/common/fs/zfs/zfs_ioctl.c
index e0d4631c7c..f479ea9f30 100644
--- a/usr/src/uts/common/fs/zfs/zfs_ioctl.c
+++ b/usr/src/uts/common/fs/zfs/zfs_ioctl.c
@@ -37,6 +37,7 @@
  * Copyright (c) 2017, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
  * Copyright 2017 RackTop Systems.
  * Copyright (c) 2017, Datto, Inc. All rights reserved.
+ * Copyright 2021 The University of Queensland
  */
 
 /*
@@ -3837,6 +3838,7 @@ zfs_ioc_destroy_bookmarks(const char *poolname, nvlist_t *innvl,
 static const zfs_ioc_key_t zfs_keys_channel_program[] = {
 	{"program",	DATA_TYPE_STRING,		0},
 	{"arg",		DATA_TYPE_ANY,			0},
+	{"hidden_args",	DATA_TYPE_ANY,			ZK_OPTIONAL},
 	{"sync",	DATA_TYPE_BOOLEAN_VALUE,	ZK_OPTIONAL},
 	{"instrlimit",	DATA_TYPE_UINT64,		ZK_OPTIONAL},
 	{"memlimit",	DATA_TYPE_UINT64,		ZK_OPTIONAL},
@@ -3850,6 +3852,7 @@ zfs_ioc_channel_program(const char *poolname, nvlist_t *innvl,
 	uint64_t instrlimit, memlimit;
 	boolean_t sync_flag;
 	nvpair_t *nvarg = NULL;
+	nvlist_t *hidden_args = NULL;
 
 	program = fnvlist_lookup_string(innvl, ZCP_ARG_PROGRAM);
 	if (0 != nvlist_lookup_boolean_value(innvl, ZCP_ARG_SYNC, &sync_flag)) {
@@ -3863,6 +3866,16 @@ zfs_ioc_channel_program(const char *poolname, nvlist_t *innvl,
 	}
 	nvarg = fnvlist_lookup_nvpair(innvl, ZCP_ARG_ARGLIST);
 
+	/* hidden args are optional */
+	if (nvlist_lookup_nvlist(innvl, ZPOOL_HIDDEN_ARGS, &hidden_args) == 0) {
+		nvlist_t *argnvl = fnvpair_value_nvlist(nvarg);
+		int ret;
+
+		ret = nvlist_add_nvlist(argnvl, ZPOOL_HIDDEN_ARGS, hidden_args);
+		if (ret != 0)
+			return (ret);
+	}
+
 	if (instrlimit == 0 || instrlimit > zfs_lua_max_instrlimit)
 		return (EINVAL);
 	if (memlimit == 0 || memlimit > zfs_lua_max_memlimit)