chapoly: add chacha20_poly1305 feature

Signed-off-by: Rob Norris <[email protected]>

include/zfeature_common.h

@@ -80,6 +80,7 @@ typedef enum spa_feature {
 	SPA_FEATURE_BLAKE3,
 	SPA_FEATURE_BLOCK_CLONING,
 	SPA_FEATURE_AVZ_V2,
+	SPA_FEATURE_CHACHA20_POLY1305,
 	SPA_FEATURES
 } spa_feature_t;
 

lib/libzfs/libzfs.abi

@@ -596,7 +596,7 @@
     <elf-symbol name='fletcher_4_superscalar_ops' size='128' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='libzfs_config_ops' size='16' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='sa_protocol_names' size='16' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
-    <elf-symbol name='spa_feature_table' size='2184' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='spa_feature_table' size='2240' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfeature_checks_disable' size='4' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_deleg_perm_tab' size='512' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_history_event_names' size='328' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -5809,7 +5809,8 @@
       <enumerator name='SPA_FEATURE_BLAKE3' value='36'/>
       <enumerator name='SPA_FEATURE_BLOCK_CLONING' value='37'/>
       <enumerator name='SPA_FEATURE_AVZ_V2' value='38'/>
-      <enumerator name='SPA_FEATURES' value='39'/>
+      <enumerator name='SPA_FEATURE_CHACHA20_POLY1305' value='39'/>
+      <enumerator name='SPA_FEATURES' value='40'/>
     </enum-decl>
     <typedef-decl name='spa_feature_t' type-id='33ecb627' id='d6618c78'/>
     <qualified-type-def type-id='22cce67b' const='yes' id='d2816df0'/>
@@ -8706,8 +8707,8 @@
     </function-decl>
   </abi-instr>
   <abi-instr address-size='64' path='module/zcommon/zfeature_common.c' language='LANG_C99'>
-    <array-type-def dimensions='1' type-id='83f29ca2' size-in-bits='17472' id='dd432c71'>
-      <subrange length='39' type-id='7359adad' id='ae4a9561'/>
+    <array-type-def dimensions='1' type-id='83f29ca2' size-in-bits='17920' id='dd432c71'>
+      <subrange length='40' type-id='7359adad' id='ae4a9561'/>
     </array-type-def>
     <enum-decl name='zfeature_flags' id='6db816a4'>
       <underlying-type type-id='9cac1fee'/>

man/man7/zpool-features.7

@@ -18,7 +18,7 @@
 .\" Copyright (c) 2019, Allan Jude
 .\" Copyright (c) 2021, Colm Buckley <[email protected]>
 .\"
-.Dd June 23, 2022
+.Dd May 21, 2023
 .Dt ZPOOL-FEATURES 7
 .Os
 .
@@ -396,6 +396,21 @@ returned to the
 .Sy enabled
 state when all bookmarks with these fields are destroyed.
 .
+.feature org.openzfs chacha20_poly1305 no encryption extensible_dataset
+This feature enables the use of the ChaCha20-Poly1305 cipher suite for encrypted
+datasets.
+On systems lackng hardware-accelerated AES (many non-x86 boards), this suite
+will usually offer better performance than AES suites without compromising
+security.
+.Pp
+This feature becomes
+.Sy active
+when an encrypted dataset is created with
+.Nm encryption Ns = Ns Sy chacha20-poly1305
+and will be returned to the
+.Sy enabled
+state when all datasets that use this feature are destroyed.
+.
 .feature org.openzfs device_rebuild yes
 This feature enables the ability for the
 .Nm zpool Cm attach

module/zcommon/zfeature_common.c

@@ -737,6 +737,19 @@ zpool_feature_init(void)
 	    ZFEATURE_FLAG_MOS, ZFEATURE_TYPE_BOOLEAN, NULL,
 	    sfeatures);
 
+	{
+		static const spa_feature_t chapoly_deps[] = {
+			SPA_FEATURE_EXTENSIBLE_DATASET,
+			SPA_FEATURE_ENCRYPTION,
+			SPA_FEATURE_NONE
+		};
+		zfeature_register(SPA_FEATURE_CHACHA20_POLY1305,
+		    "org.openzfs:chacha20_poly1305", "chacha20_poly1305",
+		    "Chacha20-Poly1305 encryption suite.",
+		    ZFEATURE_FLAG_PER_DATASET, ZFEATURE_TYPE_BOOLEAN,
+		    chapoly_deps, sfeatures);
+	}
+
 	zfs_mod_list_supported_free(sfeatures);
 }
 

module/zfs/dsl_crypt.c

@@ -1819,6 +1819,12 @@ dmu_objset_create_crypt_check(dsl_dir_t *parentdd, dsl_crypto_params_t *dcp,
 		return (SET_ERROR(EOPNOTSUPP));
 	}
 
+	if (crypt == ZIO_CRYPT_CHACHA20_POLY1305 && parentdd != NULL &&
+	    !spa_feature_is_enabled(parentdd->dd_pool->dp_spa,
+	    SPA_FEATURE_CHACHA20_POLY1305)) {
+		return (SET_ERROR(EOPNOTSUPP));
+	}
+
 	/* handle inheritance */
 	if (dcp->cp_wkey == NULL) {
 		ASSERT3P(parentdd, !=, NULL);
@@ -1937,6 +1943,9 @@ dsl_dataset_create_crypt_sync(uint64_t dsobj, dsl_dir_t *dd,
 	    tx));
 	dsl_dataset_activate_feature(dsobj, SPA_FEATURE_ENCRYPTION,
 	    (void *)B_TRUE, tx);
+	if (crypt == ZIO_CRYPT_CHACHA20_POLY1305)
+		dsl_dataset_activate_feature(dsobj,
+		    SPA_FEATURE_CHACHA20_POLY1305, (void *)B_TRUE, tx);
 
 	/*
 	 * If we inherited the wrapping key we release our reference now.
@@ -2157,6 +2166,11 @@ dsl_crypto_recv_raw_key_check(dsl_dataset_t *ds, nvlist_t *nvl, dmu_tx_t *tx)
 	if (intval >= ZIO_CRYPT_FUNCTIONS)
 		return (SET_ERROR(ZFS_ERR_CRYPTO_NOTSUP));
 
+	if (intval == ZIO_CRYPT_CHACHA20_POLY1305 &&
+	    !spa_feature_is_enabled(ds->ds_dir->dd_pool->dp_spa,
+	    SPA_FEATURE_CHACHA20_POLY1305))
+		return (SET_ERROR(EOPNOTSUPP));
+
 	ret = nvlist_lookup_uint64(nvl, DSL_CRYPTO_KEY_GUID, &intval);
 	if (ret != 0)
 		return (SET_ERROR(EINVAL));
@@ -2276,6 +2290,13 @@ dsl_crypto_recv_raw_key_sync(dsl_dataset_t *ds, nvlist_t *nvl, dmu_tx_t *tx)
 		    SPA_FEATURE_ENCRYPTION, (void *)B_TRUE, tx);
 		ds->ds_feature[SPA_FEATURE_ENCRYPTION] = (void *)B_TRUE;
 
+		if (crypt == ZIO_CRYPT_CHACHA20_POLY1305) {
+			dsl_dataset_activate_feature(ds->ds_object,
+			    SPA_FEATURE_CHACHA20_POLY1305, (void *)B_TRUE, tx);
+			ds->ds_feature[SPA_FEATURE_CHACHA20_POLY1305] =
+			    (void *)B_TRUE;
+		}
+
 		/* save the dd_crypto_obj on disk */
 		VERIFY0(zap_add(mos, dd->dd_object, DD_FIELD_CRYPTO_KEY_OBJ,
 		    sizeof (uint64_t), 1, &dd->dd_crypto_obj, tx));

module/zfs/dsl_pool.c

@@ -537,8 +537,12 @@ dsl_pool_create(spa_t *spa, nvlist_t *zplprops __attribute__((unused)),
 		spa_feature_create_zap_objects(spa, tx);
 
 	if (dcp != NULL && dcp->cp_crypt != ZIO_CRYPT_OFF &&
-	    dcp->cp_crypt != ZIO_CRYPT_INHERIT)
+	    dcp->cp_crypt != ZIO_CRYPT_INHERIT) {
 		spa_feature_enable(spa, SPA_FEATURE_ENCRYPTION, tx);
+		if (dcp->cp_crypt == ZIO_CRYPT_CHACHA20_POLY1305)
+			spa_feature_enable(spa,
+			    SPA_FEATURE_CHACHA20_POLY1305, tx);
+	}
 
 	/* create the root dataset */
 	obj = dsl_dataset_create_sync_dd(dp->dp_root_dir, NULL, dcp, 0, tx);