Add ZFS_PROP_PASSPHRASE_KDF (passphrasekdf) property and argon2id

Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>

.github/workflows/build-dependencies.txt

@@ -28,6 +28,7 @@ libmount-dev
 libpam0g-dev
 libselinux1-dev
 libssl-dev
+libargon2-dev
 libtool
 libudev-dev
 linux-headers-generic

cmd/zdb/zdb.c

@@ -42,6 +42,7 @@
 #include <stdlib.h>
 #include <ctype.h>
 #include <getopt.h>
+#include <argon2.h>
 #include <openssl/evp.h>
 #include <sys/zfs_context.h>
 #include <sys/spa.h>
@@ -3123,7 +3124,7 @@ static char *key_material = NULL;
 static boolean_t
 zdb_derive_key(dsl_dir_t *dd, uint8_t *key_out)
 {
-	uint64_t keyformat, salt, iters;
+	uint64_t keyformat, kdf = ZFS_PASSPHRASE_KDF_PBKDF2, salt, iters;
 	int i;
 	unsigned char c;
 
@@ -3151,10 +3152,32 @@ zdb_derive_key(dsl_dir_t *dd, uint8_t *key_out)
 		    dd->dd_crypto_obj, zfs_prop_to_name(ZFS_PROP_PBKDF2_ITERS),
 		    sizeof (uint64_t), 1, &iters));
 
-		if (PKCS5_PBKDF2_HMAC_SHA1(key_material, strlen(key_material),
-		    ((uint8_t *)&salt), sizeof (uint64_t), iters,
-		    WRAPPING_KEY_LEN, key_out) != 1)
-			return (B_FALSE);
+		int err = zap_lookup(dd->dd_pool->dp_meta_objset,
+		    dd->dd_crypto_obj,
+		    zfs_prop_to_name(ZFS_PROP_PASSPHRASE_KDF),
+		    sizeof (uint64_t), 1, &kdf);
+		VERIFY(err == 0 || err == ENOENT);
+
+		switch (kdf) {
+		case ZFS_PASSPHRASE_KDF_PBKDF2:
+			if (PKCS5_PBKDF2_HMAC_SHA1(key_material,
+			    strlen(key_material), ((uint8_t *)&salt),
+			    sizeof (uint64_t), iters,
+			    WRAPPING_KEY_LEN, key_out) != 1)
+				return (B_FALSE);
+			break;
+		case ZFS_PASSPHRASE_KDF_ARGON2ID:
+			if (argon2_hash(iters, 18, 1,
+			    key_material, strlen(key_material),
+			    &salt, sizeof (uint64_t), key_out, WRAPPING_KEY_LEN,
+			    NULL, 0, Argon2_id, ARGON2_VERSION_13)
+			    != ARGON2_OK)
+				return (B_FALSE);
+			break;
+		default:
+			fatal("no support for KDF %u\n",
+			    (unsigned int) kdf);
+		}
 
 		break;
 

cmd/zfs/zfs_main.c

@@ -415,8 +415,9 @@ get_usage(zfs_help_t idx)
 		    "<-a | filesystem|volume>\n"));
 	case HELP_CHANGE_KEY:
 		return (gettext("\tchange-key [-l] [-o keyformat=<value>]\n"
-		    "\t    [-o keylocation=<value>] [-o pbkdf2iters=<value>]\n"
-		    "\t    <filesystem|volume>\n"
+		    "\t    [-o keylocation=<value>] "
+		    "[-o passphrasekdf=<value>] \n"
+		    "\t    [-o pbkdf2iters=<value>] <filesystem|volume>\n"
 		    "\tchange-key -i [-l] <filesystem|volume>\n"));
 	case HELP_VERSION:
 		return (gettext("\tversion\n"));

cmd/ztest.c

@@ -4553,6 +4553,9 @@ ztest_dataset_create(char *dsname)
 		    zfs_prop_to_name(ZFS_PROP_KEYFORMAT), ZFS_KEYFORMAT_RAW);
 		fnvlist_add_string(props,
 		    zfs_prop_to_name(ZFS_PROP_KEYLOCATION), "prompt");
+		fnvlist_add_uint64(props,
+		    zfs_prop_to_name(ZFS_PROP_PASSPHRASE_KDF),
+		    ztest_random(ZFS_PASSPHRASE_KDF_KDFS));
 		fnvlist_add_uint64(props,
 		    zfs_prop_to_name(ZFS_PROP_PBKDF2_SALT), 0ULL);
 		fnvlist_add_uint64(props,

config/user-libcrypto.m4

@@ -1,8 +1,16 @@
 dnl #
-dnl # Check for libcrypto. Used for userspace password derivation via PBKDF2.
+dnl # Check for libcrypto and libargon. Used for userspace password derivation via PBKDF2 and argon2id.
 dnl #
 AC_DEFUN([ZFS_AC_CONFIG_USER_LIBCRYPTO], [
-	ZFS_AC_FIND_SYSTEM_LIBRARY(LIBCRYPTO, [libcrypto], [openssl/evp.h], [], [crypto], [PKCS5_PBKDF2_HMAC_SHA1], [], [
-		AC_MSG_FAILURE([
-		*** evp.h missing, libssl-devel package required])])
+	ZFS_AC_FIND_SYSTEM_LIBRARY(LIBCRYPTO_SSL, [libcrypto], [openssl/evp.h], [], [crypto], [PKCS5_PBKDF2_HMAC_SHA1], [], [
+		AC_MSG_FAILURE([*** evp.h missing, libssl-devel package required])])
+
+	# ARGON2 is included in openssl 3.2: once this is widely distributed, we should detect it and drop the libargon2 dep
+	ZFS_AC_FIND_SYSTEM_LIBRARY(LIBCRYPTO_ARGON2, [libargon2], [argon2.h], [], [argon2], [argon2id_hash_raw], [], [
+		AC_MSG_FAILURE([*** libargon2-dev package required])])
+
+	LIBCRYPTO_CFLAGS="$LIBCRYPTO_SSL_CFLAGS $LIBCRYPTO_ARGON2_CFLAGS"
+	LIBCRYPTO_LIBS="$LIBCRYPTO_SSL_LIBS $LIBCRYPTO_ARGON2_LIBS"
+	AC_SUBST(LIBCRYPTO_CFLAGS, [])
+	AC_SUBST(LIBCRYPTO_LIBS, [])
 ])

contrib/pam_zfs_key/pam_zfs_key.c

@@ -33,6 +33,7 @@
 
 #include <sys/zio_crypt.h>
 #include <openssl/evp.h>
+#include <argon2.h>
 
 #define	PAM_SM_AUTH
 #define	PAM_SM_PASSWORD
@@ -250,17 +251,24 @@ static pw_password_t *
 prepare_passphrase(pam_handle_t *pamh, zfs_handle_t *ds,
     const char *passphrase, nvlist_t *nvlist)
 {
+	const char *errstr = NULL;
 	pw_password_t *key = alloc_pw_size(WRAPPING_KEY_LEN);
 	if (!key) {
 		return (NULL);
 	}
-	uint64_t salt;
-	uint64_t iters;
+	uint64_t kdf, salt, iters;
 	if (nvlist != NULL) {
+		kdf = ZFS_PASSPHRASE_KDF_PBKDF2;
+		if (nvlist_add_uint64(nvlist,
+		    zfs_prop_to_name(ZFS_PROP_PASSPHRASE_KDF), kdf)) {
+			errstr = "failed to add KDF to nvlist";
+			goto err;
+		}
+
 		int fd = open("/dev/urandom", O_RDONLY);
 		if (fd < 0) {
-			pw_free(key);
-			return (NULL);
+			errstr = "/dev/urandom";
+			goto err;
 		}
 		int bytes_read = 0;
 		char *buf = (char *)&salt;
@@ -270,43 +278,60 @@ prepare_passphrase(pam_handle_t *pamh, zfs_handle_t *ds,
 			    - bytes_read);
 			if (len < 0) {
 				close(fd);
-				pw_free(key);
-				return (NULL);
+				errstr = "failed to read salt";
+				goto err;
 			}
 			bytes_read += len;
 		}
 		close(fd);
 
 		if (nvlist_add_uint64(nvlist,
 		    zfs_prop_to_name(ZFS_PROP_PBKDF2_SALT), salt)) {
-			pam_syslog(pamh, LOG_ERR,
-			    "failed to add salt to nvlist");
-			pw_free(key);
-			return (NULL);
+			errstr = "failed to add salt to nvlist";
+			goto err;
 		}
-		iters = DEFAULT_PBKDF2_ITERATIONS;
+		iters = zfs_passphrase_kdf_default_iterations[kdf];
 		if (nvlist_add_uint64(nvlist, zfs_prop_to_name(
 		    ZFS_PROP_PBKDF2_ITERS), iters)) {
-			pam_syslog(pamh, LOG_ERR,
-			    "failed to add iters to nvlist");
-			pw_free(key);
-			return (NULL);
+			errstr = "failed to add iters to nvlist";
+			goto err;
 		}
 	} else {
+		kdf = zfs_prop_get_int(ds, ZFS_PROP_PASSPHRASE_KDF);
 		salt = zfs_prop_get_int(ds, ZFS_PROP_PBKDF2_SALT);
 		iters = zfs_prop_get_int(ds, ZFS_PROP_PBKDF2_ITERS);
 	}
 
 	salt = LE_64(salt);
-	if (!PKCS5_PBKDF2_HMAC_SHA1((char *)passphrase,
-	    strlen(passphrase), (uint8_t *)&salt,
-	    sizeof (uint64_t), iters, WRAPPING_KEY_LEN,
-	    (uint8_t *)key->value)) {
-		pam_syslog(pamh, LOG_ERR, "pbkdf failed");
-		pw_free(key);
-		return (NULL);
-	}
+
+	switch (kdf) {
+	case ZFS_PASSPHRASE_KDF_PBKDF2:
+		if (PKCS5_PBKDF2_HMAC_SHA1((char *)passphrase,
+		    strlen(passphrase), ((uint8_t *)&salt),
+		    sizeof (uint64_t), iters, WRAPPING_KEY_LEN,
+		    (uint8_t *)key->value) != 1)
+			errstr = "PBKDF2 failed";
+		break;
+	case ZFS_PASSPHRASE_KDF_ARGON2ID:
+		if (argon2_hash(iters, 18, 1,
+		    passphrase, strlen((char *)passphrase),
+		    &salt, sizeof (uint64_t), (uint8_t *)key->value,
+		    WRAPPING_KEY_LEN, NULL, 0, Argon2_id, ARGON2_VERSION_13)
+		    != ARGON2_OK)
+			errstr = "ARGON2ID13 failed";
+		break;
+	default:
+		errstr = "unknown KDF";
+		break;
+	}
+	if (errstr)
+		goto err;
 	return (key);
+
+err:
+	pam_syslog(pamh, LOG_ERR, "%s", errstr);
+	pw_free(key);
+	return (NULL);
 }
 
 static int

contrib/pyzfs/libzfs_core/_libzfs_core.py

@@ -836,8 +836,8 @@ def lzc_change_key(fsname, crypt_cmd, props=None, key=None):
         supported values are "new_key", "inherit", "force_new_key" and
         "force_inherit".
     :param props: a `dict` of encryption-related property name-value pairs;
-        only "keyformat", "keylocation" and "pbkdf2iters" are supported
-        (empty by default).
+        only "keyformat", "keylocation", "passphrasepkdf", and "pbkdf2iters"
+        are supported (empty by default).
     :type props: dict of bytes:Any
     :param key: dataset encryption key data (empty by default).
     :type key: bytes

include/sys/dsl_crypt.h

@@ -28,8 +28,9 @@
 
 /*
  * ZAP entry keys for DSL Crypto Keys stored on disk. In addition,
- * ZFS_PROP_KEYFORMAT, ZFS_PROP_PBKDF2_SALT, and ZFS_PROP_PBKDF2_ITERS are
- * also maintained here using their respective property names.
+ * ZFS_PROP_KEYFORMAT, ZFS_PROP_PBKDF2_SALT, ZFS_PROP_PBKDF2_ITERS,
+ * and ZFS_PROP_PASSPHRASE_KDF are also maintained here using their
+ * respective property names.
  */
 #define	DSL_CRYPTO_KEY_CRYPTO_SUITE	"DSL_CRYPTO_SUITE"
 #define	DSL_CRYPTO_KEY_GUID		"DSL_CRYPTO_GUID"
@@ -52,10 +53,13 @@ typedef struct dsl_wrapping_key {
 	/* keyformat property enum */
 	zfs_keyformat_t wk_keyformat;
 
-	/* the pbkdf2 salt, if the keyformat is of type passphrase */
+	/* the KDF to use, if the keyformat is of type passphrase */
+	zfs_passphrase_kdf_t wk_kdf;
+
+	/* the KDF salt, if the keyformat is of type passphrase */
 	uint64_t wk_salt;
 
-	/* the pbkdf2 iterations, if the keyformat is of type passphrase */
+	/* the KDF iterations, if the keyformat is of type passphrase */
 	uint64_t wk_iters;
 
 	/* actual wrapping key */

include/sys/fs/zfs.h

@@ -193,6 +193,7 @@ typedef enum {
 	ZFS_PROP_SNAPSHOTS_CHANGED,
 	ZFS_PROP_PREFETCH,
 	ZFS_PROP_VOLTHREADING,
+	ZFS_PROP_PASSPHRASE_KDF,
 	ZFS_NUM_PROPS
 } zfs_prop_t;
 
@@ -539,6 +540,17 @@ typedef enum zfs_keyformat {
 	ZFS_KEYFORMAT_FORMATS
 } zfs_keyformat_t;
 
+typedef enum zfs_passphrase_kdf {
+	ZFS_PASSPHRASE_KDF_PBKDF2 = 0,
+	ZFS_PASSPHRASE_KDF_ARGON2ID,
+	ZFS_PASSPHRASE_KDF_KDFS
+} zfs_passphrase_kdf_t;
+
+static const uint32_t zfs_passphrase_kdf_default_iterations[
+    ZFS_PASSPHRASE_KDF_KDFS] = {350000, 40000};
+static const uint32_t zfs_passphrase_kdf_min_iterations[
+    ZFS_PASSPHRASE_KDF_KDFS] = {100000, 10000};
+
 typedef enum zfs_key_location {
 	ZFS_KEYLOCATION_NONE = 0,
 	ZFS_KEYLOCATION_PROMPT,
@@ -552,9 +564,6 @@ typedef enum {
 	ZFS_PREFETCH_ALL = 2
 } zfs_prefetch_type_t;
 
-#define	DEFAULT_PBKDF2_ITERATIONS 350000
-#define	MIN_PBKDF2_ITERATIONS 100000
-
 /*
  * On-disk version number.
  */

lib/libzfs/libzfs.abi

@@ -1822,7 +1822,8 @@
       <enumerator name='ZFS_PROP_SNAPSHOTS_CHANGED' value='95'/>
       <enumerator name='ZFS_PROP_PREFETCH' value='96'/>
       <enumerator name='ZFS_PROP_VOLTHREADING' value='97'/>
-      <enumerator name='ZFS_NUM_PROPS' value='98'/>
+      <enumerator name='ZFS_PROP_PASSPHRASE_KDF' value='98'/>
+      <enumerator name='ZFS_NUM_PROPS' value='99'/>
     </enum-decl>
     <typedef-decl name='zfs_prop_t' type-id='4b000d60' id='58603c44'/>
     <enum-decl name='zprop_source_t' naming-typedef-id='a2256d42' id='5903f80e'>