zfs-builds-mm/zfs-0.8.1/lib/libzfs/libzfs_crypto.c

1518 lines
38 KiB
C
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2019-07-06 23:40:11 +02:00
/*
* 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 (c) 2017, Datto, Inc. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/fs/zfs.h>
#include <sys/dsl_crypt.h>
#include <libintl.h>
#include <termios.h>
#include <signal.h>
#include <errno.h>
#include <openssl/evp.h>
#include <libzfs.h>
#include "libzfs_impl.h"
#include "zfeature_common.h"
/*
* User keys are used to decrypt the master encryption keys of a dataset. This
* indirection allows a user to change his / her access key without having to
* re-encrypt the entire dataset. User keys can be provided in one of several
* ways. Raw keys are simply given to the kernel as is. Similarly, hex keys
* are converted to binary and passed into the kernel. Password based keys are
* a bit more complicated. Passwords alone do not provide suitable entropy for
* encryption and may be too short or too long to be used. In order to derive
* a more appropriate key we use a PBKDF2 function. This function is designed
* to take a (relatively) long time to calculate in order to discourage
* attackers from guessing from a list of common passwords. PBKDF2 requires
* 2 additional parameters. The first is the number of iterations to run, which
* will ultimately determine how long it takes to derive the resulting key from
* the password. The second parameter is a salt that is randomly generated for
* each dataset. The salt is used to "tweak" PBKDF2 such that a group of
* attackers cannot reasonably generate a table of commonly known passwords to
* their output keys and expect it work for all past and future PBKDF2 users.
* We store the salt as a hidden property of the dataset (although it is
* technically ok if the salt is known to the attacker).
*/
typedef enum key_locator {
KEY_LOCATOR_NONE,
KEY_LOCATOR_PROMPT,
KEY_LOCATOR_URI
} key_locator_t;
#define MIN_PASSPHRASE_LEN 8
#define MAX_PASSPHRASE_LEN 512
#define MAX_KEY_PROMPT_ATTEMPTS 3
static int caught_interrupt;
static int
pkcs11_get_urandom(uint8_t *buf, size_t bytes)
{
int rand;
ssize_t bytes_read = 0;
rand = open("/dev/urandom", O_RDONLY);
if (rand < 0)
return (rand);
while (bytes_read < bytes) {
ssize_t rc = read(rand, buf + bytes_read, bytes - bytes_read);
if (rc < 0)
break;
bytes_read += rc;
}
(void) close(rand);
return (bytes_read);
}
static zfs_keylocation_t
zfs_prop_parse_keylocation(const char *str)
{
if (strcmp("prompt", str) == 0)
return (ZFS_KEYLOCATION_PROMPT);
else if (strlen(str) > 8 && strncmp("file:///", str, 8) == 0)
return (ZFS_KEYLOCATION_URI);
return (ZFS_KEYLOCATION_NONE);
}
static int
hex_key_to_raw(char *hex, int hexlen, uint8_t *out)
{
int ret, i;
unsigned int c;
for (i = 0; i < hexlen; i += 2) {
if (!isxdigit(hex[i]) || !isxdigit(hex[i + 1])) {
ret = EINVAL;
goto error;
}
ret = sscanf(&hex[i], "%02x", &c);
if (ret != 1) {
ret = EINVAL;
goto error;
}
out[i / 2] = c;
}
return (0);
error:
return (ret);
}
static void
catch_signal(int sig)
{
caught_interrupt = sig;
}
static const char *
get_format_prompt_string(zfs_keyformat_t format)
{
switch (format) {
case ZFS_KEYFORMAT_RAW:
return ("raw key");
case ZFS_KEYFORMAT_HEX:
return ("hex key");
case ZFS_KEYFORMAT_PASSPHRASE:
return ("passphrase");
default:
/* shouldn't happen */
return (NULL);
}
}
static int
get_key_material_raw(FILE *fd, const char *fsname, zfs_keyformat_t keyformat,
boolean_t again, boolean_t newkey, uint8_t **buf, size_t *len_out)
{
int ret = 0, bytes;
size_t buflen = 0;
struct termios old_term, new_term;
struct sigaction act, osigint, osigtstp;
*len_out = 0;
if (isatty(fileno(fd))) {
/*
* handle SIGINT and ignore SIGSTP. This is necessary to
* restore the state of the terminal.
*/
caught_interrupt = 0;
act.sa_flags = 0;
(void) sigemptyset(&act.sa_mask);
act.sa_handler = catch_signal;
(void) sigaction(SIGINT, &act, &osigint);
act.sa_handler = SIG_IGN;
(void) sigaction(SIGTSTP, &act, &osigtstp);
/* prompt for the key */
if (fsname != NULL) {
(void) printf("%s %s%s for '%s': ",
(again) ? "Re-enter" : "Enter",
(newkey) ? "new " : "",
get_format_prompt_string(keyformat), fsname);
} else {
(void) printf("%s %s%s: ",
(again) ? "Re-enter" : "Enter",
(newkey) ? "new " : "",
get_format_prompt_string(keyformat));
}
(void) fflush(stdout);
/* disable the terminal echo for key input */
(void) tcgetattr(fileno(fd), &old_term);
new_term = old_term;
new_term.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
ret = tcsetattr(fileno(fd), TCSAFLUSH, &new_term);
if (ret != 0) {
ret = errno;
errno = 0;
goto out;
}
}
/* read the key material */
if (keyformat != ZFS_KEYFORMAT_RAW) {
bytes = getline((char **)buf, &buflen, fd);
if (bytes < 0) {
ret = errno;
errno = 0;
goto out;
}
/* trim the ending newline if it exists */
if ((*buf)[bytes - 1] == '\n') {
(*buf)[bytes - 1] = '\0';
bytes--;
}
} else {
/*
* Raw keys may have newline characters in them and so can't
* use getline(). Here we attempt to read 33 bytes so that we
* can properly check the key length (the file should only have
* 32 bytes).
*/
*buf = malloc((WRAPPING_KEY_LEN + 1) * sizeof (char));
if (*buf == NULL) {
ret = ENOMEM;
goto out;
}
bytes = fread(*buf, 1, WRAPPING_KEY_LEN + 1, fd);
if (bytes < 0) {
/* size errors are handled by the calling function */
free(*buf);
*buf = NULL;
ret = errno;
errno = 0;
goto out;
}
}
*len_out = bytes;
out:
if (isatty(fileno(fd))) {
/* reset the teminal */
(void) tcsetattr(fileno(fd), TCSAFLUSH, &old_term);
(void) sigaction(SIGINT, &osigint, NULL);
(void) sigaction(SIGTSTP, &osigtstp, NULL);
/* if we caught a signal, re-throw it now */
if (caught_interrupt != 0) {
(void) kill(getpid(), caught_interrupt);
}
/* print the newline that was not echo'd */
printf("\n");
}
return (ret);
}
/*
* Attempts to fetch key material, no matter where it might live. The key
* material is allocated and returned in km_out. *can_retry_out will be set
* to B_TRUE if the user is providing the key material interactively, allowing
* for re-entry attempts.
*/
static int
get_key_material(libzfs_handle_t *hdl, boolean_t do_verify, boolean_t newkey,
zfs_keyformat_t keyformat, char *keylocation, const char *fsname,
uint8_t **km_out, size_t *kmlen_out, boolean_t *can_retry_out)
{
int ret, i;
zfs_keylocation_t keyloc = ZFS_KEYLOCATION_NONE;
FILE *fd = NULL;
uint8_t *km = NULL, *km2 = NULL;
size_t kmlen, kmlen2;
boolean_t can_retry = B_FALSE;
/* verify and parse the keylocation */
keyloc = zfs_prop_parse_keylocation(keylocation);
/* open the appropriate file descriptor */
switch (keyloc) {
case ZFS_KEYLOCATION_PROMPT:
fd = stdin;
if (isatty(fileno(fd))) {
can_retry = B_TRUE;
/* raw keys cannot be entered on the terminal */
if (keyformat == ZFS_KEYFORMAT_RAW) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Cannot enter raw keys on the terminal"));
goto error;
}
}
break;
case ZFS_KEYLOCATION_URI:
fd = fopen(&keylocation[7], "r");
if (!fd) {
ret = errno;
errno = 0;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Failed to open key material file"));
goto error;
}
break;
default:
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Invalid keylocation."));
goto error;
}
/* fetch the key material into the buffer */
ret = get_key_material_raw(fd, fsname, keyformat, B_FALSE, newkey,
&km, &kmlen);
if (ret != 0)
goto error;
/* do basic validation of the key material */
switch (keyformat) {
case ZFS_KEYFORMAT_RAW:
/* verify the key length is correct */
if (kmlen < WRAPPING_KEY_LEN) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Raw key too short (expected %u)."),
WRAPPING_KEY_LEN);
goto error;
}
if (kmlen > WRAPPING_KEY_LEN) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Raw key too long (expected %u)."),
WRAPPING_KEY_LEN);
goto error;
}
break;
case ZFS_KEYFORMAT_HEX:
/* verify the key length is correct */
if (kmlen < WRAPPING_KEY_LEN * 2) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Hex key too short (expected %u)."),
WRAPPING_KEY_LEN * 2);
goto error;
}
if (kmlen > WRAPPING_KEY_LEN * 2) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Hex key too long (expected %u)."),
WRAPPING_KEY_LEN * 2);
goto error;
}
/* check for invalid hex digits */
for (i = 0; i < WRAPPING_KEY_LEN * 2; i++) {
if (!isxdigit((char)km[i])) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Invalid hex character detected."));
goto error;
}
}
break;
case ZFS_KEYFORMAT_PASSPHRASE:
/* verify the length is within bounds */
if (kmlen > MAX_PASSPHRASE_LEN) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Passphrase too long (max %u)."),
MAX_PASSPHRASE_LEN);
goto error;
}
if (kmlen < MIN_PASSPHRASE_LEN) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Passphrase too short (min %u)."),
MIN_PASSPHRASE_LEN);
goto error;
}
break;
default:
/* can't happen, checked above */
break;
}
if (do_verify && isatty(fileno(fd))) {
ret = get_key_material_raw(fd, fsname, keyformat, B_TRUE,
newkey, &km2, &kmlen2);
if (ret != 0)
goto error;
if (kmlen2 != kmlen ||
(memcmp((char *)km, (char *)km2, kmlen) != 0)) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Provided keys do not match."));
goto error;
}
}
if (fd != stdin)
fclose(fd);
if (km2 != NULL)
free(km2);
*km_out = km;
*kmlen_out = kmlen;
if (can_retry_out != NULL)
*can_retry_out = can_retry;
return (0);
error:
if (km != NULL)
free(km);
if (km2 != NULL)
free(km2);
if (fd != NULL && fd != stdin)
fclose(fd);
*km_out = NULL;
*kmlen_out = 0;
if (can_retry_out != NULL)
*can_retry_out = can_retry;
return (ret);
}
static int
derive_key(libzfs_handle_t *hdl, zfs_keyformat_t format, uint64_t iters,
uint8_t *key_material, size_t key_material_len, uint64_t salt,
uint8_t **key_out)
{
int ret;
uint8_t *key;
*key_out = NULL;
key = zfs_alloc(hdl, WRAPPING_KEY_LEN);
if (!key)
return (ENOMEM);
switch (format) {
case ZFS_KEYFORMAT_RAW:
bcopy(key_material, key, WRAPPING_KEY_LEN);
break;
case ZFS_KEYFORMAT_HEX:
ret = hex_key_to_raw((char *)key_material,
WRAPPING_KEY_LEN * 2, key);
if (ret != 0) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Invalid hex key provided."));
goto error;
}
break;
case ZFS_KEYFORMAT_PASSPHRASE:
salt = LE_64(salt);
ret = PKCS5_PBKDF2_HMAC_SHA1((char *)key_material,
strlen((char *)key_material), ((uint8_t *)&salt),
sizeof (uint64_t), iters, WRAPPING_KEY_LEN, key);
if (ret != 1) {
ret = EIO;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Failed to generate key from passphrase."));
goto error;
}
break;
default:
ret = EINVAL;
goto error;
}
*key_out = key;
return (0);
error:
free(key);
*key_out = NULL;
return (ret);
}
static boolean_t
encryption_feature_is_enabled(zpool_handle_t *zph)
{
nvlist_t *features;
uint64_t feat_refcount;
/* check that features can be enabled */
if (zpool_get_prop_int(zph, ZPOOL_PROP_VERSION, NULL)
< SPA_VERSION_FEATURES)
return (B_FALSE);
/* check for crypto feature */
features = zpool_get_features(zph);
if (!features || nvlist_lookup_uint64(features,
spa_feature_table[SPA_FEATURE_ENCRYPTION].fi_guid,
&feat_refcount) != 0)
return (B_FALSE);
return (B_TRUE);
}
static int
populate_create_encryption_params_nvlists(libzfs_handle_t *hdl,
zfs_handle_t *zhp, boolean_t newkey, zfs_keyformat_t keyformat,
char *keylocation, nvlist_t *props, uint8_t **wkeydata, uint_t *wkeylen)
{
int ret;
uint64_t iters = 0, salt = 0;
uint8_t *key_material = NULL;
size_t key_material_len = 0;
uint8_t *key_data = NULL;
const char *fsname = (zhp) ? zfs_get_name(zhp) : NULL;
/* get key material from keyformat and keylocation */
ret = get_key_material(hdl, B_TRUE, newkey, keyformat, keylocation,
fsname, &key_material, &key_material_len, NULL);
if (ret != 0)
goto error;
/* passphrase formats require a salt and pbkdf2 iters property */
if (keyformat == ZFS_KEYFORMAT_PASSPHRASE) {
/* always generate a new salt */
ret = pkcs11_get_urandom((uint8_t *)&salt, sizeof (uint64_t));
if (ret != sizeof (uint64_t)) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Failed to generate salt."));
goto error;
}
ret = nvlist_add_uint64(props,
zfs_prop_to_name(ZFS_PROP_PBKDF2_SALT), salt);
if (ret != 0) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Failed to add salt to properties."));
goto error;
}
/*
* If not otherwise specified, use the default number of
* pbkdf2 iterations. If specified, we have already checked
* that the given value is greater than MIN_PBKDF2_ITERATIONS
* during zfs_valid_proplist().
*/
ret = nvlist_lookup_uint64(props,
zfs_prop_to_name(ZFS_PROP_PBKDF2_ITERS), &iters);
if (ret == ENOENT) {
iters = DEFAULT_PBKDF2_ITERATIONS;
ret = nvlist_add_uint64(props,
zfs_prop_to_name(ZFS_PROP_PBKDF2_ITERS), iters);
if (ret != 0)
goto error;
} else if (ret != 0) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Failed to get pbkdf2 iterations."));
goto error;
}
} else {
/* check that pbkdf2iters was not specified by the user */
ret = nvlist_lookup_uint64(props,
zfs_prop_to_name(ZFS_PROP_PBKDF2_ITERS), &iters);
if (ret == 0) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Cannot specify pbkdf2iters with a non-passphrase "
"keyformat."));
goto error;
}
}
/* derive a key from the key material */
ret = derive_key(hdl, keyformat, iters, key_material, key_material_len,
salt, &key_data);
if (ret != 0)
goto error;
free(key_material);
*wkeydata = key_data;
*wkeylen = WRAPPING_KEY_LEN;
return (0);
error:
if (key_material != NULL)
free(key_material);
if (key_data != NULL)
free(key_data);
*wkeydata = NULL;
*wkeylen = 0;
return (ret);
}
static boolean_t
proplist_has_encryption_props(nvlist_t *props)
{
int ret;
uint64_t intval;
char *strval;
ret = nvlist_lookup_uint64(props,
zfs_prop_to_name(ZFS_PROP_ENCRYPTION), &intval);
if (ret == 0 && intval != ZIO_CRYPT_OFF)
return (B_TRUE);
ret = nvlist_lookup_string(props,
zfs_prop_to_name(ZFS_PROP_KEYLOCATION), &strval);
if (ret == 0 && strcmp(strval, "none") != 0)
return (B_TRUE);
ret = nvlist_lookup_uint64(props,
zfs_prop_to_name(ZFS_PROP_KEYFORMAT), &intval);
if (ret == 0)
return (B_TRUE);
ret = nvlist_lookup_uint64(props,
zfs_prop_to_name(ZFS_PROP_PBKDF2_ITERS), &intval);
if (ret == 0)
return (B_TRUE);
return (B_FALSE);
}
int
zfs_crypto_get_encryption_root(zfs_handle_t *zhp, boolean_t *is_encroot,
char *buf)
{
int ret;
char prop_encroot[MAXNAMELEN];
/* if the dataset isn't encrypted, just return */
if (zfs_prop_get_int(zhp, ZFS_PROP_ENCRYPTION) == ZIO_CRYPT_OFF) {
*is_encroot = B_FALSE;
if (buf != NULL)
buf[0] = '\0';
return (0);
}
ret = zfs_prop_get(zhp, ZFS_PROP_ENCRYPTION_ROOT, prop_encroot,
sizeof (prop_encroot), NULL, NULL, 0, B_TRUE);
if (ret != 0) {
*is_encroot = B_FALSE;
if (buf != NULL)
buf[0] = '\0';
return (ret);
}
*is_encroot = strcmp(prop_encroot, zfs_get_name(zhp)) == 0;
if (buf != NULL)
strcpy(buf, prop_encroot);
return (0);
}
int
zfs_crypto_create(libzfs_handle_t *hdl, char *parent_name, nvlist_t *props,
nvlist_t *pool_props, boolean_t stdin_available, uint8_t **wkeydata_out,
uint_t *wkeylen_out)
{
int ret;
char errbuf[1024];
uint64_t crypt = ZIO_CRYPT_INHERIT, pcrypt = ZIO_CRYPT_INHERIT;
uint64_t keyformat = ZFS_KEYFORMAT_NONE;
char *keylocation = NULL;
zfs_handle_t *pzhp = NULL;
uint8_t *wkeydata = NULL;
uint_t wkeylen = 0;
boolean_t local_crypt = B_TRUE;
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "Encryption create error"));
/* lookup crypt from props */
ret = nvlist_lookup_uint64(props,
zfs_prop_to_name(ZFS_PROP_ENCRYPTION), &crypt);
if (ret != 0)
local_crypt = B_FALSE;
/* lookup key location and format from props */
(void) nvlist_lookup_uint64(props,
zfs_prop_to_name(ZFS_PROP_KEYFORMAT), &keyformat);
(void) nvlist_lookup_string(props,
zfs_prop_to_name(ZFS_PROP_KEYLOCATION), &keylocation);
if (parent_name != NULL) {
/* get a reference to parent dataset */
pzhp = make_dataset_handle(hdl, parent_name);
if (pzhp == NULL) {
ret = ENOENT;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Failed to lookup parent."));
goto out;
}
/* Lookup parent's crypt */
pcrypt = zfs_prop_get_int(pzhp, ZFS_PROP_ENCRYPTION);
/* Params require the encryption feature */
if (!encryption_feature_is_enabled(pzhp->zpool_hdl)) {
if (proplist_has_encryption_props(props)) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Encryption feature not enabled."));
goto out;
}
ret = 0;
goto out;
}
} else {
/*
* special case for root dataset where encryption feature
* feature won't be on disk yet
*/
if (!nvlist_exists(pool_props, "feature@encryption")) {
if (proplist_has_encryption_props(props)) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Encryption feature not enabled."));
goto out;
}
ret = 0;
goto out;
}
pcrypt = ZIO_CRYPT_OFF;
}
/* Check for encryption being explicitly truned off */
if (crypt == ZIO_CRYPT_OFF && pcrypt != ZIO_CRYPT_OFF) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Invalid encryption value. Dataset must be encrypted."));
goto out;
}
/* Get the inherited encryption property if we don't have it locally */
if (!local_crypt)
crypt = pcrypt;
/*
* At this point crypt should be the actual encryption value. If
* encryption is off just verify that no encryption properties have
* been specified and return.
*/
if (crypt == ZIO_CRYPT_OFF) {
if (proplist_has_encryption_props(props)) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Encryption must be turned on to set encryption "
"properties."));
goto out;
}
ret = 0;
goto out;
}
/*
* If we have a parent crypt it is valid to specify encryption alone.
* This will result in a child that is encrypted with the chosen
* encryption suite that will also inherit the parent's key. If
* the parent is not encrypted we need an encryption suite provided.
*/
if (pcrypt == ZIO_CRYPT_OFF && keylocation == NULL &&
keyformat == ZFS_KEYFORMAT_NONE) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Keyformat required for new encryption root."));
goto out;
}
/*
* Specifying a keylocation implies this will be a new encryption root.
* Check that a keyformat is also specified.
*/
if (keylocation != NULL && keyformat == ZFS_KEYFORMAT_NONE) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Keyformat required for new encryption root."));
goto out;
}
/* default to prompt if no keylocation is specified */
if (keyformat != ZFS_KEYFORMAT_NONE && keylocation == NULL) {
keylocation = "prompt";
ret = nvlist_add_string(props,
zfs_prop_to_name(ZFS_PROP_KEYLOCATION), keylocation);
if (ret != 0)
goto out;
}
/*
* If a local key is provided, this dataset will be a new
* encryption root. Populate the encryption params.
*/
if (keylocation != NULL) {
/*
* 'zfs recv -o keylocation=prompt' won't work because stdin
* is being used by the send stream, so we disallow it.
*/
if (!stdin_available && strcmp(keylocation, "prompt") == 0) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "Cannot use "
"'prompt' keylocation because stdin is in use."));
goto out;
}
ret = populate_create_encryption_params_nvlists(hdl, NULL,
B_FALSE, keyformat, keylocation, props, &wkeydata,
&wkeylen);
if (ret != 0)
goto out;
}
if (pzhp != NULL)
zfs_close(pzhp);
*wkeydata_out = wkeydata;
*wkeylen_out = wkeylen;
return (0);
out:
if (pzhp != NULL)
zfs_close(pzhp);
if (wkeydata != NULL)
free(wkeydata);
*wkeydata_out = NULL;
*wkeylen_out = 0;
return (ret);
}
int
zfs_crypto_clone_check(libzfs_handle_t *hdl, zfs_handle_t *origin_zhp,
char *parent_name, nvlist_t *props)
{
int ret;
char errbuf[1024];
zfs_handle_t *pzhp = NULL;
uint64_t pcrypt, ocrypt;
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "Encryption clone error"));
/*
* No encryption properties should be specified. They will all be
* inherited from the origin dataset.
*/
if (nvlist_exists(props, zfs_prop_to_name(ZFS_PROP_KEYFORMAT)) ||
nvlist_exists(props, zfs_prop_to_name(ZFS_PROP_KEYLOCATION)) ||
nvlist_exists(props, zfs_prop_to_name(ZFS_PROP_ENCRYPTION)) ||
nvlist_exists(props, zfs_prop_to_name(ZFS_PROP_PBKDF2_ITERS))) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Encryption properties must inherit from origin dataset."));
goto out;
}
/* get a reference to parent dataset, should never be NULL */
pzhp = make_dataset_handle(hdl, parent_name);
if (pzhp == NULL) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Failed to lookup parent."));
return (ENOENT);
}
/* Lookup parent's crypt */
pcrypt = zfs_prop_get_int(pzhp, ZFS_PROP_ENCRYPTION);
ocrypt = zfs_prop_get_int(origin_zhp, ZFS_PROP_ENCRYPTION);
/* all children of encrypted parents must be encrypted */
if (pcrypt != ZIO_CRYPT_OFF && ocrypt == ZIO_CRYPT_OFF) {
ret = EINVAL;
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Cannot create unencrypted clone as a child "
"of encrypted parent."));
goto out;
}
zfs_close(pzhp);
return (0);
out:
if (pzhp != NULL)
zfs_close(pzhp);
return (ret);
}
typedef struct loadkeys_cbdata {
uint64_t cb_numfailed;
uint64_t cb_numattempted;
} loadkey_cbdata_t;
static int
load_keys_cb(zfs_handle_t *zhp, void *arg)
{
int ret;
boolean_t is_encroot;
loadkey_cbdata_t *cb = arg;
uint64_t keystatus = zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS);
/* only attempt to load keys for encryption roots */
ret = zfs_crypto_get_encryption_root(zhp, &is_encroot, NULL);
if (ret != 0 || !is_encroot)
goto out;
/* don't attempt to load already loaded keys */
if (keystatus == ZFS_KEYSTATUS_AVAILABLE)
goto out;
/* Attempt to load the key. Record status in cb. */
cb->cb_numattempted++;
ret = zfs_crypto_load_key(zhp, B_FALSE, NULL);
if (ret)
cb->cb_numfailed++;
out:
(void) zfs_iter_filesystems(zhp, load_keys_cb, cb);
zfs_close(zhp);
/* always return 0, since this function is best effort */
return (0);
}
/*
* This function is best effort. It attempts to load all the keys for the given
* filesystem and all of its children.
*/
int
zfs_crypto_attempt_load_keys(libzfs_handle_t *hdl, char *fsname)
{
int ret;
zfs_handle_t *zhp = NULL;
loadkey_cbdata_t cb = { 0 };
zhp = zfs_open(hdl, fsname, ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME);
if (zhp == NULL) {
ret = ENOENT;
goto error;
}
ret = load_keys_cb(zfs_handle_dup(zhp), &cb);
if (ret)
goto error;
(void) printf(gettext("%llu / %llu keys successfully loaded\n"),
(u_longlong_t)(cb.cb_numattempted - cb.cb_numfailed),
(u_longlong_t)cb.cb_numattempted);
if (cb.cb_numfailed != 0) {
ret = -1;
goto error;
}
zfs_close(zhp);
return (0);
error:
if (zhp != NULL)
zfs_close(zhp);
return (ret);
}
int
zfs_crypto_load_key(zfs_handle_t *zhp, boolean_t noop, char *alt_keylocation)
{
int ret, attempts = 0;
char errbuf[1024];
uint64_t keystatus, iters = 0, salt = 0;
uint64_t keyformat = ZFS_KEYFORMAT_NONE;
char prop_keylocation[MAXNAMELEN];
char prop_encroot[MAXNAMELEN];
char *keylocation = NULL;
uint8_t *key_material = NULL, *key_data = NULL;
size_t key_material_len;
boolean_t is_encroot, can_retry = B_FALSE, correctible = B_FALSE;
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "Key load error"));
/* check that encryption is enabled for the pool */
if (!encryption_feature_is_enabled(zhp->zpool_hdl)) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Encryption feature not enabled."));
ret = EINVAL;
goto error;
}
/* Fetch the keyformat. Check that the dataset is encrypted. */
keyformat = zfs_prop_get_int(zhp, ZFS_PROP_KEYFORMAT);
if (keyformat == ZFS_KEYFORMAT_NONE) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"'%s' is not encrypted."), zfs_get_name(zhp));
ret = EINVAL;
goto error;
}
/*
* Fetch the key location. Check that we are working with an
* encryption root.
*/
ret = zfs_crypto_get_encryption_root(zhp, &is_encroot, prop_encroot);
if (ret != 0) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Failed to get encryption root for '%s'."),
zfs_get_name(zhp));
goto error;
} else if (!is_encroot) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Keys must be loaded for encryption root of '%s' (%s)."),
zfs_get_name(zhp), prop_encroot);
ret = EINVAL;
goto error;
}
/*
* if the caller has elected to override the keylocation property
* use that instead
*/
if (alt_keylocation != NULL) {
keylocation = alt_keylocation;
} else {
ret = zfs_prop_get(zhp, ZFS_PROP_KEYLOCATION, prop_keylocation,
sizeof (prop_keylocation), NULL, NULL, 0, B_TRUE);
if (ret != 0) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Failed to get keylocation for '%s'."),
zfs_get_name(zhp));
goto error;
}
keylocation = prop_keylocation;
}
/* check that the key is unloaded unless this is a noop */
if (!noop) {
keystatus = zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS);
if (keystatus == ZFS_KEYSTATUS_AVAILABLE) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Key already loaded for '%s'."), zfs_get_name(zhp));
ret = EEXIST;
goto error;
}
}
/* passphrase formats require a salt and pbkdf2_iters property */
if (keyformat == ZFS_KEYFORMAT_PASSPHRASE) {
salt = zfs_prop_get_int(zhp, ZFS_PROP_PBKDF2_SALT);
iters = zfs_prop_get_int(zhp, ZFS_PROP_PBKDF2_ITERS);
}
try_again:
/* fetching and deriving the key are correctable errors. set the flag */
correctible = B_TRUE;
/* get key material from key format and location */
ret = get_key_material(zhp->zfs_hdl, B_FALSE, B_FALSE, keyformat,
keylocation, zfs_get_name(zhp), &key_material, &key_material_len,
&can_retry);
if (ret != 0)
goto error;
/* derive a key from the key material */
ret = derive_key(zhp->zfs_hdl, keyformat, iters, key_material,
key_material_len, salt, &key_data);
if (ret != 0)
goto error;
correctible = B_FALSE;
/* pass the wrapping key and noop flag to the ioctl */
ret = lzc_load_key(zhp->zfs_name, noop, key_data, WRAPPING_KEY_LEN);
if (ret != 0) {
switch (ret) {
case EPERM:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Permission denied."));
break;
case EINVAL:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Invalid parameters provided for dataset %s."),
zfs_get_name(zhp));
break;
case EEXIST:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Key already loaded for '%s'."), zfs_get_name(zhp));
break;
case EBUSY:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"'%s' is busy."), zfs_get_name(zhp));
break;
case EACCES:
correctible = B_TRUE;
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Incorrect key provided for '%s'."),
zfs_get_name(zhp));
break;
}
goto error;
}
free(key_material);
free(key_data);
return (0);
error:
zfs_error(zhp->zfs_hdl, EZFS_CRYPTOFAILED, errbuf);
if (key_material != NULL) {
free(key_material);
key_material = NULL;
}
if (key_data != NULL) {
free(key_data);
key_data = NULL;
}
/*
* Here we decide if it is ok to allow the user to retry entering their
* key. The can_retry flag will be set if the user is entering their
* key from an interactive prompt. The correctable flag will only be
* set if an error that occurred could be corrected by retrying. Both
* flags are needed to allow the user to attempt key entry again
*/
attempts++;
if (can_retry && correctible && attempts < MAX_KEY_PROMPT_ATTEMPTS)
goto try_again;
return (ret);
}
int
zfs_crypto_unload_key(zfs_handle_t *zhp)
{
int ret;
char errbuf[1024];
char prop_encroot[MAXNAMELEN];
uint64_t keystatus, keyformat;
boolean_t is_encroot;
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "Key unload error"));
/* check that encryption is enabled for the pool */
if (!encryption_feature_is_enabled(zhp->zpool_hdl)) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Encryption feature not enabled."));
ret = EINVAL;
goto error;
}
/* Fetch the keyformat. Check that the dataset is encrypted. */
keyformat = zfs_prop_get_int(zhp, ZFS_PROP_KEYFORMAT);
if (keyformat == ZFS_KEYFORMAT_NONE) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"'%s' is not encrypted."), zfs_get_name(zhp));
ret = EINVAL;
goto error;
}
/*
* Fetch the key location. Check that we are working with an
* encryption root.
*/
ret = zfs_crypto_get_encryption_root(zhp, &is_encroot, prop_encroot);
if (ret != 0) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Failed to get encryption root for '%s'."),
zfs_get_name(zhp));
goto error;
} else if (!is_encroot) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Keys must be unloaded for encryption root of '%s' (%s)."),
zfs_get_name(zhp), prop_encroot);
ret = EINVAL;
goto error;
}
/* check that the key is loaded */
keystatus = zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS);
if (keystatus == ZFS_KEYSTATUS_UNAVAILABLE) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Key already unloaded for '%s'."), zfs_get_name(zhp));
ret = EACCES;
goto error;
}
/* call the ioctl */
ret = lzc_unload_key(zhp->zfs_name);
if (ret != 0) {
switch (ret) {
case EPERM:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Permission denied."));
break;
case EACCES:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Key already unloaded for '%s'."),
zfs_get_name(zhp));
break;
case EBUSY:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"'%s' is busy."), zfs_get_name(zhp));
break;
}
zfs_error(zhp->zfs_hdl, EZFS_CRYPTOFAILED, errbuf);
}
return (ret);
error:
zfs_error(zhp->zfs_hdl, EZFS_CRYPTOFAILED, errbuf);
return (ret);
}
static int
zfs_crypto_verify_rewrap_nvlist(zfs_handle_t *zhp, nvlist_t *props,
nvlist_t **props_out, char *errbuf)
{
int ret;
nvpair_t *elem = NULL;
zfs_prop_t prop;
nvlist_t *new_props = NULL;
new_props = fnvlist_alloc();
/*
* loop through all provided properties, we should only have
* keyformat, keylocation and pbkdf2iters. The actual validation of
* values is done by zfs_valid_proplist().
*/
while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
const char *propname = nvpair_name(elem);
prop = zfs_name_to_prop(propname);
switch (prop) {
case ZFS_PROP_PBKDF2_ITERS:
case ZFS_PROP_KEYFORMAT:
case ZFS_PROP_KEYLOCATION:
break;
default:
ret = EINVAL;
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Only keyformat, keylocation and pbkdf2iters may "
"be set with this command."));
goto error;
}
}
new_props = zfs_valid_proplist(zhp->zfs_hdl, zhp->zfs_type, props,
zfs_prop_get_int(zhp, ZFS_PROP_ZONED), NULL, zhp->zpool_hdl,
B_TRUE, errbuf);
if (new_props == NULL) {
ret = EINVAL;
goto error;
}
*props_out = new_props;
return (0);
error:
nvlist_free(new_props);
*props_out = NULL;
return (ret);
}
int
zfs_crypto_rewrap(zfs_handle_t *zhp, nvlist_t *raw_props, boolean_t inheritkey)
{
int ret;
char errbuf[1024];
boolean_t is_encroot;
nvlist_t *props = NULL;
uint8_t *wkeydata = NULL;
uint_t wkeylen = 0;
dcp_cmd_t cmd = (inheritkey) ? DCP_CMD_INHERIT : DCP_CMD_NEW_KEY;
uint64_t crypt, pcrypt, keystatus, pkeystatus;
uint64_t keyformat = ZFS_KEYFORMAT_NONE;
zfs_handle_t *pzhp = NULL;
char *keylocation = NULL;
char origin_name[MAXNAMELEN];
char prop_keylocation[MAXNAMELEN];
char parent_name[ZFS_MAX_DATASET_NAME_LEN];
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "Key change error"));
/* check that encryption is enabled for the pool */
if (!encryption_feature_is_enabled(zhp->zpool_hdl)) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Encryption feature not enabled."));
ret = EINVAL;
goto error;
}
/* get crypt from dataset */
crypt = zfs_prop_get_int(zhp, ZFS_PROP_ENCRYPTION);
if (crypt == ZIO_CRYPT_OFF) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Dataset not encrypted."));
ret = EINVAL;
goto error;
}
/* get the encryption root of the dataset */
ret = zfs_crypto_get_encryption_root(zhp, &is_encroot, NULL);
if (ret != 0) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Failed to get encryption root for '%s'."),
zfs_get_name(zhp));
goto error;
}
/* Clones use their origin's key and cannot rewrap it */
ret = zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin_name,
sizeof (origin_name), NULL, NULL, 0, B_TRUE);
if (ret == 0 && strcmp(origin_name, "") != 0) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Keys cannot be changed on clones."));
ret = EINVAL;
goto error;
}
/*
* If the user wants to use the inheritkey variant of this function
* we don't need to collect any crypto arguments.
*/
if (!inheritkey) {
/* validate the provided properties */
ret = zfs_crypto_verify_rewrap_nvlist(zhp, raw_props, &props,
errbuf);
if (ret != 0)
goto error;
/*
* Load keyformat and keylocation from the nvlist. Fetch from
* the dataset properties if not specified.
*/
(void) nvlist_lookup_uint64(props,
zfs_prop_to_name(ZFS_PROP_KEYFORMAT), &keyformat);
(void) nvlist_lookup_string(props,
zfs_prop_to_name(ZFS_PROP_KEYLOCATION), &keylocation);
if (is_encroot) {
/*
* If this is already an ecryption root, just keep
* any properties not set by the user.
*/
if (keyformat == ZFS_KEYFORMAT_NONE) {
keyformat = zfs_prop_get_int(zhp,
ZFS_PROP_KEYFORMAT);
ret = nvlist_add_uint64(props,
zfs_prop_to_name(ZFS_PROP_KEYFORMAT),
keyformat);
if (ret != 0) {
zfs_error_aux(zhp->zfs_hdl,
dgettext(TEXT_DOMAIN, "Failed to "
"get existing keyformat "
"property."));
goto error;
}
}
if (keylocation == NULL) {
ret = zfs_prop_get(zhp, ZFS_PROP_KEYLOCATION,
prop_keylocation, sizeof (prop_keylocation),
NULL, NULL, 0, B_TRUE);
if (ret != 0) {
zfs_error_aux(zhp->zfs_hdl,
dgettext(TEXT_DOMAIN, "Failed to "
"get existing keylocation "
"property."));
goto error;
}
keylocation = prop_keylocation;
}
} else {
/* need a new key for non-encryption roots */
if (keyformat == ZFS_KEYFORMAT_NONE) {
ret = EINVAL;
zfs_error_aux(zhp->zfs_hdl,
dgettext(TEXT_DOMAIN, "Keyformat required "
"for new encryption root."));
goto error;
}
/* default to prompt if no keylocation is specified */
if (keylocation == NULL) {
keylocation = "prompt";
ret = nvlist_add_string(props,
zfs_prop_to_name(ZFS_PROP_KEYLOCATION),
keylocation);
if (ret != 0)
goto error;
}
}
/* fetch the new wrapping key and associated properties */
ret = populate_create_encryption_params_nvlists(zhp->zfs_hdl,
zhp, B_TRUE, keyformat, keylocation, props, &wkeydata,
&wkeylen);
if (ret != 0)
goto error;
} else {
/* check that zhp is an encryption root */
if (!is_encroot) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Key inheritting can only be performed on "
"encryption roots."));
ret = EINVAL;
goto error;
}
/* get the parent's name */
ret = zfs_parent_name(zhp, parent_name, sizeof (parent_name));
if (ret != 0) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Root dataset cannot inherit key."));
ret = EINVAL;
goto error;
}
/* get a handle to the parent */
pzhp = make_dataset_handle(zhp->zfs_hdl, parent_name);
if (pzhp == NULL) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Failed to lookup parent."));
ret = ENOENT;
goto error;
}
/* parent must be encrypted */
pcrypt = zfs_prop_get_int(pzhp, ZFS_PROP_ENCRYPTION);
if (pcrypt == ZIO_CRYPT_OFF) {
zfs_error_aux(pzhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Parent must be encrypted."));
ret = EINVAL;
goto error;
}
/* check that the parent's key is loaded */
pkeystatus = zfs_prop_get_int(pzhp, ZFS_PROP_KEYSTATUS);
if (pkeystatus == ZFS_KEYSTATUS_UNAVAILABLE) {
zfs_error_aux(pzhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Parent key must be loaded."));
ret = EACCES;
goto error;
}
}
/* check that the key is loaded */
keystatus = zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS);
if (keystatus == ZFS_KEYSTATUS_UNAVAILABLE) {
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Key must be loaded."));
ret = EACCES;
goto error;
}
/* call the ioctl */
ret = lzc_change_key(zhp->zfs_name, cmd, props, wkeydata, wkeylen);
if (ret != 0) {
switch (ret) {
case EPERM:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Permission denied."));
break;
case EINVAL:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Invalid properties for key change."));
break;
case EACCES:
zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
"Key is not currently loaded."));
break;
}
zfs_error(zhp->zfs_hdl, EZFS_CRYPTOFAILED, errbuf);
}
if (pzhp != NULL)
zfs_close(pzhp);
if (props != NULL)
nvlist_free(props);
if (wkeydata != NULL)
free(wkeydata);
return (ret);
error:
if (pzhp != NULL)
zfs_close(pzhp);
if (props != NULL)
nvlist_free(props);
if (wkeydata != NULL)
free(wkeydata);
zfs_error(zhp->zfs_hdl, EZFS_CRYPTOFAILED, errbuf);
return (ret);
}