Chacha20-Poly1305 encryption

This commit implements the Chacha20-Poly1305 AEAD from RFC 8439 as a new
algorithm option for encrypted datasets.

AES (and particularly the default AES-GCM mode used in OpenZFS) is known
to be very slow on systems without hardware assistance. There are many
such machines out there could make good use of OpenZFS, especially
low-cost machines and small boards that would otherwise make very nice
storage machines. The Raspberry Pi series of machines are a good
example.

The best option for these systems is an encryption option that performs
well in software. Chacha20-Poly1305 is the current "standard" option for
this in many contexts, and is a good choice for OpenZFS.

The core Chacha20 and Poly1305 implementations are taken from Loup
Valliant's Monocypher. These were chosen because they are compact, easy
to read, easy to use and the author has written extensively about its
development, all of which give me confidence that there are unlikely to
be any surprises.

I've added a KCF-style module to the ICP to implement the AEAD. This
implements just enough for OpenZFS, and is not suitable as a
general-purpose KCF for Illumos (though it could be the starting point
for one).

For FreeBSD, which does not use the ICP, I've instead hooked it up to
FreeBSD's builtin crypto stack.

The rest is adding an enabling property value and a feature flag and and
hooking it up to all the right touch points, and documentation updates.

The existing tests that cycle through the possible encryption options
have been extended to add one more.

I've added a test to ensure that raw receives of chacha20-poly1305
datasets do the right thing based on the state of the feature flag on
the receiving side.

There's also a test unit that runs the test vectors in RFC 8439 against
Chacha20, Poly1305 and the AEAD in the ICP that combines them. This is
most useful as a sanity check during future work to add alternate
(accelerated) implementations.

Finally, manual interop testing has been done to confirm that pools and
streams can be moved between Linux and FreeBSD correctly.

Light and uncontrolled performance testing on a Raspberry Pi 4B
(Broadcom BCM2711, no hardware AES) writing to a chacha20-poly1305
dataset was ~2.4x faster than aes-256-gcm on the same hardware. On a
Fitlet2 (Celeron J3455, AES-NI but no AVX (#10846)) it was ~1.3x faster.

Sponsored-by: https://despairlabs.com/sponsor/
Signed-off-by: Rob Norris <robn@despairlabs.com>

Author: robn

Makefile.am

@@ -124,6 +124,7 @@ cstyle:
 		! -name 'zfs_config.*' ! -name '*.mod.c' \
 		! -name 'opt_global.h' ! -name '*_if*.h' \
 		! -name 'zstd_compat_wrapper.h' \
+		! -name 'monocypher.[ch]' \
 		! -path './module/zstd/lib/*' \
 		! -path './include/sys/lua/*' \
 		! -path './module/lua/l*.[ch]' \

include/os/freebsd/zfs/sys/freebsd_crypto.h

@@ -41,6 +41,7 @@
 #define	SUN_CKM_AES_CCM	"CKM_AES_CCM"
 #define	SUN_CKM_AES_GCM	"CKM_AES_GCM"
 #define	SUN_CKM_SHA512_HMAC	"CKM_SHA512_HMAC"
+#define	SUN_CKM_CHACHA20_POLY1305	"CKM_CHACHA20_POLY1305"
 
 #define	CRYPTO_BITS2BYTES(n) ((n) == 0 ? 0 : (((n) - 1) >> 3) + 1)
 #define	CRYPTO_BYTES2BITS(n) ((n) << 3)

include/sys/crypto/common.h

@@ -82,6 +82,7 @@ typedef uint32_t crypto_keysize_unit_t;
 #define	SUN_CKM_SHA512_HMAC		"CKM_SHA512_HMAC"
 #define	SUN_CKM_AES_CCM			"CKM_AES_CCM"
 #define	SUN_CKM_AES_GCM			"CKM_AES_GCM"
+#define	SUN_CKM_CHACHA20_POLY1305	"CKM_CHACHA20_POLY1305"
 
 /* Data arguments of cryptographic operations */
 

include/sys/crypto/icp.h

@@ -26,6 +26,9 @@
 #ifndef	_SYS_CRYPTO_ALGS_H
 #define	_SYS_CRYPTO_ALGS_H
 
+int chapoly_mod_init(void);
+int chapoly_mod_fini(void);
+
 int aes_mod_init(void);
 int aes_mod_fini(void);
 

include/sys/fs/zfs.h

@@ -1888,6 +1888,7 @@ enum zio_encrypt {
 	ZIO_CRYPT_AES_128_GCM,
 	ZIO_CRYPT_AES_192_GCM,
 	ZIO_CRYPT_AES_256_GCM,
+	ZIO_CRYPT_CHACHA20_POLY1305,
 	ZIO_CRYPT_FUNCTIONS
 };
 

include/sys/zio_crypt.h

@@ -45,7 +45,8 @@ struct zbookmark_phys;
 typedef enum zio_crypt_type {
 	ZC_TYPE_NONE = 0,
 	ZC_TYPE_CCM,
-	ZC_TYPE_GCM
+	ZC_TYPE_GCM,
+	ZC_TYPE_CHACHA20_POLY1305,
 } zio_crypt_type_t;
 
 /* table of supported crypto algorithms, modes and keylengths. */
@@ -60,7 +61,7 @@ typedef struct zio_crypt_info {
 #else
 	crypto_mech_name_t ci_mechname;
 #endif
-	/* cipher mode type (GCM, CCM) */
+	/* cipher mode type (GCM, CCM, ChaCha20-Poly1305) */
 	zio_crypt_type_t ci_crypt_type;
 
 	/* length of the encryption key */

include/zfeature_common.h

@@ -83,6 +83,7 @@ typedef enum spa_feature {
 	SPA_FEATURE_REDACTION_LIST_SPILL,
 	SPA_FEATURE_RAIDZ_EXPANSION,
 	SPA_FEATURE_FAST_DEDUP,
+	SPA_FEATURE_CHACHA20_POLY1305,
 	SPA_FEATURES
 } spa_feature_t;
 

lib/libicp/Makefile.am

@@ -29,8 +29,10 @@ nodist_libicp_la_SOURCES = \
 	module/icp/algs/skein/skein_block.c \
 	module/icp/algs/skein/skein_iv.c \
 	module/icp/illumos-crypto.c \
+	module/icp/monocypher.c \
 	module/icp/io/aes.c \
 	module/icp/io/sha2_mod.c \
+	module/icp/io/chapoly.c \
 	module/icp/core/kcf_sched.c \
 	module/icp/core/kcf_prov_lib.c \
 	module/icp/core/kcf_callprov.c \

lib/libzfs/libzfs.abi

@@ -183,8 +183,8 @@
     <elf-symbol name='fsleep' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='get_dataset_depth' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='get_system_hostid' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
-    <elf-symbol name='getexecname' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='get_timestamp' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='getexecname' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='getextmntent' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='getmntany' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='getprop_uint64' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -466,6 +466,7 @@
     <elf-symbol name='zpool_clear' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_clear_label' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_close' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zpool_collect_unsup_feat' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_create' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_default_search_paths' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_destroy' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -485,8 +486,8 @@
     <elf-symbol name='zpool_export_force' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_feature_init' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_find_config' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
-    <elf-symbol name='zpool_find_vdev' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_find_parent_vdev' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='zpool_find_vdev' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_find_vdev_by_physpath' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_free_handles' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_get_all_vdev_props' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -529,7 +530,6 @@
     <elf-symbol name='zpool_prefetch' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_prepare_and_label_disk' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_prepare_disk' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
-    <elf-symbol name='zpool_collect_unsup_feat' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_prop_align_right' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_prop_column_name' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zpool_prop_default_numeric' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -616,7 +616,7 @@
     <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='2352' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='spa_feature_table' size='2408' 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'/>
@@ -6007,7 +6007,8 @@
       <enumerator name='SPA_FEATURE_REDACTION_LIST_SPILL' value='39'/>
       <enumerator name='SPA_FEATURE_RAIDZ_EXPANSION' value='40'/>
       <enumerator name='SPA_FEATURE_FAST_DEDUP' value='41'/>
-      <enumerator name='SPA_FEATURES' value='42'/>
+      <enumerator name='SPA_FEATURE_CHACHA20_POLY1305' value='42'/>
+      <enumerator name='SPA_FEATURES' value='43'/>
     </enum-decl>
     <typedef-decl name='spa_feature_t' type-id='33ecb627' id='d6618c78'/>
     <qualified-type-def type-id='80f4b756' const='yes' id='b99c00c9'/>
@@ -7831,7 +7832,7 @@
       </data-member>
     </class-decl>
     <typedef-decl name='vdev_cbdata_t' type-id='b8006be8' id='a9679c94'/>
-    <class-decl name='zprop_get_cbdata' size-in-bits='832' is-struct='yes' visibility='default' id='f3d3c319'>
+    <class-decl name='zprop_get_cbdata' size-in-bits='960' is-struct='yes' visibility='default' id='f3d3c319'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='cb_sources' type-id='95e97e5e' visibility='default'/>
       </data-member>
@@ -7850,6 +7851,9 @@
       <data-member access='public' layout-offset-in-bits='448'>
         <var-decl name='cb_first' type-id='c19b74c3' visibility='default'/>
       </data-member>
+      <data-member access='public' layout-offset-in-bits='480'>
+        <var-decl name='cb_json' type-id='c19b74c3' visibility='default'/>
+      </data-member>
       <data-member access='public' layout-offset-in-bits='512'>
         <var-decl name='cb_proplist' type-id='3a9b2288' visibility='default'/>
       </data-member>
@@ -7859,6 +7863,15 @@
       <data-member access='public' layout-offset-in-bits='640'>
         <var-decl name='cb_vdevs' type-id='a9679c94' visibility='default'/>
       </data-member>
+      <data-member access='public' layout-offset-in-bits='832'>
+        <var-decl name='cb_jsobj' type-id='5ce45b60' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='896'>
+        <var-decl name='cb_json_as_int' type-id='c19b74c3' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='928'>
+        <var-decl name='cb_json_pool_key_guid' type-id='c19b74c3' visibility='default'/>
+      </data-member>
     </class-decl>
     <typedef-decl name='zprop_get_cbdata_t' type-id='f3d3c319' id='f3d87113'/>
     <typedef-decl name='zprop_func' type-id='2e711a2a' id='1ec3747a'/>
@@ -7962,6 +7975,11 @@
     <qualified-type-def type-id='d33f11cb' restrict='yes' id='5c53ba29'/>
     <pointer-type-def type-id='ffa52b96' size-in-bits='64' id='76c8174b'/>
     <pointer-type-def type-id='f3d87113' size-in-bits='64' id='0d2a0670'/>
+    <function-decl name='nvlist_print_json' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='822cd80b'/>
+      <parameter type-id='5ce45b60'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
     <function-decl name='zpool_label_disk' mangled-name='zpool_label_disk' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_label_disk'>
       <parameter type-id='b0382bb3'/>
       <parameter type-id='4c81de99'/>
@@ -8069,6 +8087,11 @@
       <parameter type-id='d33f11cb'/>
       <return type-id='48b5725f'/>
     </function-decl>
+    <function-decl name='putc' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='822cd80b'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
     <function-decl name='puts' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <return type-id='95e97e5e'/>
@@ -8087,6 +8110,11 @@
       <parameter type-id='95e97e5e'/>
       <return type-id='48b5725f'/>
     </function-decl>
+    <function-decl name='strspn' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='80f4b756'/>
+      <parameter type-id='80f4b756'/>
+      <return type-id='b59d7dce'/>
+    </function-decl>
     <function-decl name='strnlen' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <parameter type-id='b59d7dce'/>
@@ -8286,12 +8314,12 @@
     <function-decl name='zfs_version_print' mangled-name='zfs_version_print' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_version_print'>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='use_color' mangled-name='use_color' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='use_color'>
-      <return type-id='95e97e5e'/>
-    </function-decl>
     <function-decl name='zfs_version_nvlist' mangled-name='zfs_version_nvlist' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_version_nvlist'>
       <return type-id='5ce45b60'/>
     </function-decl>
+    <function-decl name='use_color' mangled-name='use_color' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='use_color'>
+      <return type-id='95e97e5e'/>
+    </function-decl>
     <function-decl name='printf_color' mangled-name='printf_color' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='printf_color'>
       <parameter type-id='80f4b756' name='color'/>
       <parameter type-id='80f4b756' name='format'/>
@@ -8796,11 +8824,6 @@
       <parameter type-id='78c01427'/>
       <return type-id='13956559'/>
     </function-decl>
-    <function-decl name='strspn' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='80f4b756'/>
-      <parameter type-id='80f4b756'/>
-      <return type-id='b59d7dce'/>
-    </function-decl>
     <function-decl name='zfs_dirnamelen' mangled-name='zfs_dirnamelen' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_dirnamelen'>
       <parameter type-id='80f4b756' name='path'/>
       <return type-id='79a0948f'/>
@@ -9132,8 +9155,8 @@
     </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='18816' id='b937914f'>
-      <subrange length='42' type-id='7359adad' id='cb7c937f'/>
+    <array-type-def dimensions='1' type-id='83f29ca2' size-in-bits='19264' id='bd39d632'>
+      <subrange length='43' type-id='7359adad' id='8f7e73a2'/>
     </array-type-def>
     <enum-decl name='zfeature_flags' id='6db816a4'>
       <underlying-type type-id='9cac1fee'/>
@@ -9210,7 +9233,7 @@
     <pointer-type-def type-id='611586a1' size-in-bits='64' id='2e243169'/>
     <qualified-type-def type-id='eaa32e2f' const='yes' id='83be723c'/>
     <pointer-type-def type-id='83be723c' size-in-bits='64' id='7acd98a2'/>
-    <var-decl name='spa_feature_table' type-id='b937914f' mangled-name='spa_feature_table' visibility='default' elf-symbol-id='spa_feature_table'/>
+    <var-decl name='spa_feature_table' type-id='bd39d632' mangled-name='spa_feature_table' visibility='default' elf-symbol-id='spa_feature_table'/>
     <var-decl name='zfeature_checks_disable' type-id='c19b74c3' mangled-name='zfeature_checks_disable' visibility='default' elf-symbol-id='zfeature_checks_disable'/>
     <function-decl name='opendir' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>

man/man7/zfsprops.7

@@ -37,8 +37,9 @@
 .\" Copyright 2019 Joyent, Inc.
 .\" Copyright (c) 2019, Kjeld Schouten-Lebbing
 .\" Copyright (c) 2022 Hewlett Packard Enterprise Development LP.
+.\" Copyright (c) 2023, Rob Norris <robn@despairlabs.com>
 .\"
-.Dd June 29, 2024
+.Dd July 26, 2024
 .Dt ZFSPROPS 7
 .Os
 .
@@ -1077,7 +1078,7 @@ This property can also be referred to by its shortened column name,
 .It Xo
 .Sy encryption Ns = Ns Sy off Ns | Ns Sy on Ns | Ns Sy aes-128-ccm Ns | Ns
 .Sy aes-192-ccm Ns | Ns Sy aes-256-ccm Ns | Ns Sy aes-128-gcm Ns | Ns
-.Sy aes-192-gcm Ns | Ns Sy aes-256-gcm
+.Sy aes-192-gcm Ns | Ns Sy aes-256-gcm Ns | Ns Sy chacha20-poly1305
 .Xc
 Controls the encryption cipher suite (block cipher, key length, and mode) used
 for this dataset.
@@ -1096,6 +1097,12 @@ selected, which is currently
 In order to provide consistent data protection, encryption must be specified at
 dataset creation time and it cannot be changed afterwards.
 .Pp
+On systems lacking hardware-accelerated AES (many non-x86 boards)
+.Sy chacha20-poly1305
+will usually offer better performance without compromising security.
+On x86, or when datasets may be mounted on on older versions of ZFS, an AES
+suite is the best choice.
+.Pp
 For more details and caveats about encryption see the
 .Sx Encryption
 section of