Luca Boccassi
896cc0da98
Some tokens support authorization via fingerprint or other biometric ID. Add support for "user verification" to cryptenroll and cryptsetup. Disable by default, as it is still quite uncommon.
236 lines
9.4 KiB
C
236 lines
9.4 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
|
|
|
|
#include "ask-password-api.h"
|
|
#include "cryptsetup-fido2.h"
|
|
#include "fileio.h"
|
|
#include "hexdecoct.h"
|
|
#include "json.h"
|
|
#include "libfido2-util.h"
|
|
#include "parse-util.h"
|
|
#include "random-util.h"
|
|
#include "strv.h"
|
|
|
|
int acquire_fido2_key(
|
|
const char *volume_name,
|
|
const char *friendly_name,
|
|
const char *device,
|
|
const char *rp_id,
|
|
const void *cid,
|
|
size_t cid_size,
|
|
const char *key_file,
|
|
size_t key_file_size,
|
|
uint64_t key_file_offset,
|
|
const void *key_data,
|
|
size_t key_data_size,
|
|
usec_t until,
|
|
bool headless,
|
|
Fido2EnrollFlags required,
|
|
void **ret_decrypted_key,
|
|
size_t *ret_decrypted_key_size) {
|
|
|
|
AskPasswordFlags flags = ASK_PASSWORD_PUSH_CACHE | ASK_PASSWORD_ACCEPT_CACHED;
|
|
_cleanup_strv_free_erase_ char **pins = NULL;
|
|
_cleanup_free_ void *loaded_salt = NULL;
|
|
const char *salt;
|
|
size_t salt_size;
|
|
char *e;
|
|
int r;
|
|
|
|
assert(cid);
|
|
assert(key_file || key_data);
|
|
|
|
if (key_data) {
|
|
salt = key_data;
|
|
salt_size = key_data_size;
|
|
} else {
|
|
_cleanup_free_ char *bindname = NULL;
|
|
|
|
/* If we read the salt via AF_UNIX, make this client recognizable */
|
|
if (asprintf(&bindname, "@%" PRIx64"/cryptsetup-fido2/%s", random_u64(), volume_name) < 0)
|
|
return log_oom();
|
|
|
|
r = read_full_file_full(
|
|
AT_FDCWD, key_file,
|
|
key_file_offset == 0 ? UINT64_MAX : key_file_offset,
|
|
key_file_size == 0 ? SIZE_MAX : key_file_size,
|
|
READ_FULL_FILE_CONNECT_SOCKET,
|
|
bindname,
|
|
(char**) &loaded_salt, &salt_size);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
salt = loaded_salt;
|
|
}
|
|
|
|
e = getenv("PIN");
|
|
if (e) {
|
|
pins = strv_new(e);
|
|
if (!pins)
|
|
return log_oom();
|
|
|
|
string_erase(e);
|
|
if (unsetenv("PIN") < 0)
|
|
return log_error_errno(errno, "Failed to unset $PIN: %m");
|
|
}
|
|
|
|
for (;;) {
|
|
if (!FLAGS_SET(required, FIDO2ENROLL_PIN) || pins) {
|
|
r = fido2_use_hmac_hash(
|
|
device,
|
|
rp_id ?: "io.systemd.cryptsetup",
|
|
salt, salt_size,
|
|
cid, cid_size,
|
|
pins,
|
|
required,
|
|
ret_decrypted_key,
|
|
ret_decrypted_key_size);
|
|
if (!IN_SET(r,
|
|
-ENOANO, /* needs pin */
|
|
-ENOLCK)) /* pin incorrect */
|
|
return r;
|
|
}
|
|
|
|
pins = strv_free_erase(pins);
|
|
|
|
if (headless)
|
|
return log_error_errno(SYNTHETIC_ERRNO(ENOPKG), "PIN querying disabled via 'headless' option. Use the '$PIN' environment variable.");
|
|
|
|
r = ask_password_auto("Please enter security token PIN:", "drive-harddisk", NULL, "fido2-pin", "cryptsetup.fido2-pin", until, flags, &pins);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to ask for user password: %m");
|
|
|
|
flags &= ~ASK_PASSWORD_ACCEPT_CACHED;
|
|
}
|
|
}
|
|
|
|
int find_fido2_auto_data(
|
|
struct crypt_device *cd,
|
|
char **ret_rp_id,
|
|
void **ret_salt,
|
|
size_t *ret_salt_size,
|
|
void **ret_cid,
|
|
size_t *ret_cid_size,
|
|
int *ret_keyslot,
|
|
Fido2EnrollFlags *ret_required) {
|
|
|
|
_cleanup_free_ void *cid = NULL, *salt = NULL;
|
|
size_t cid_size = 0, salt_size = 0;
|
|
_cleanup_free_ char *rp = NULL;
|
|
int r, keyslot = -1;
|
|
/* For backward compatibility, require pin and presence by default */
|
|
Fido2EnrollFlags required = FIDO2ENROLL_PIN | FIDO2ENROLL_UP;
|
|
|
|
assert(cd);
|
|
assert(ret_salt);
|
|
assert(ret_salt_size);
|
|
assert(ret_cid);
|
|
assert(ret_cid_size);
|
|
assert(ret_keyslot);
|
|
assert(ret_required);
|
|
|
|
/* Loads FIDO2 metadata from LUKS2 JSON token headers. */
|
|
|
|
for (int token = 0; token < sym_crypt_token_max(CRYPT_LUKS2); token ++) {
|
|
_cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
|
|
JsonVariant *w;
|
|
|
|
r = cryptsetup_get_token_as_json(cd, token, "systemd-fido2", &v);
|
|
if (IN_SET(r, -ENOENT, -EINVAL, -EMEDIUMTYPE))
|
|
continue;
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to read JSON token data off disk: %m");
|
|
|
|
if (cid)
|
|
return log_error_errno(SYNTHETIC_ERRNO(ENOTUNIQ),
|
|
"Multiple FIDO2 tokens enrolled, cannot automatically determine token.");
|
|
|
|
w = json_variant_by_key(v, "fido2-credential");
|
|
if (!w || !json_variant_is_string(w))
|
|
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
|
|
"FIDO2 token data lacks 'fido2-credential' field.");
|
|
|
|
r = unbase64mem(json_variant_string(w), SIZE_MAX, &cid, &cid_size);
|
|
if (r < 0)
|
|
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
|
|
"Invalid base64 data in 'fido2-credential' field.");
|
|
|
|
w = json_variant_by_key(v, "fido2-salt");
|
|
if (!w || !json_variant_is_string(w))
|
|
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
|
|
"FIDO2 token data lacks 'fido2-salt' field.");
|
|
|
|
assert(!salt);
|
|
assert(salt_size == 0);
|
|
r = unbase64mem(json_variant_string(w), SIZE_MAX, &salt, &salt_size);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to decode base64 encoded salt.");
|
|
|
|
assert(keyslot < 0);
|
|
keyslot = cryptsetup_get_keyslot_from_token(v);
|
|
if (keyslot < 0)
|
|
return log_error_errno(keyslot, "Failed to extract keyslot index from FIDO2 JSON data: %m");
|
|
|
|
w = json_variant_by_key(v, "fido2-rp");
|
|
if (w) {
|
|
/* The "rp" field is optional. */
|
|
|
|
if (!json_variant_is_string(w))
|
|
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
|
|
"FIDO2 token data's 'fido2-rp' field is not a string.");
|
|
|
|
assert(!rp);
|
|
rp = strdup(json_variant_string(w));
|
|
if (!rp)
|
|
return log_oom();
|
|
}
|
|
|
|
w = json_variant_by_key(v, "fido2-clientPin-required");
|
|
if (w) {
|
|
/* The "fido2-clientPin-required" field is optional. */
|
|
|
|
if (!json_variant_is_boolean(w))
|
|
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
|
|
"FIDO2 token data's 'fido2-clientPin-required' field is not a boolean.");
|
|
|
|
SET_FLAG(required, FIDO2ENROLL_PIN, json_variant_boolean(w));
|
|
}
|
|
|
|
w = json_variant_by_key(v, "fido2-up-required");
|
|
if (w) {
|
|
/* The "fido2-up-required" field is optional. */
|
|
|
|
if (!json_variant_is_boolean(w))
|
|
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
|
|
"FIDO2 token data's 'fido2-up-required' field is not a boolean.");
|
|
|
|
SET_FLAG(required, FIDO2ENROLL_UP, json_variant_boolean(w));
|
|
}
|
|
|
|
w = json_variant_by_key(v, "fido2-uv-required");
|
|
if (w) {
|
|
/* The "fido2-uv-required" field is optional. */
|
|
|
|
if (!json_variant_is_boolean(w))
|
|
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
|
|
"FIDO2 token data's 'fido2-uv-required' field is not a boolean.");
|
|
|
|
SET_FLAG(required, FIDO2ENROLL_UV, json_variant_boolean(w));
|
|
}
|
|
}
|
|
|
|
if (!cid)
|
|
return log_error_errno(SYNTHETIC_ERRNO(ENXIO),
|
|
"No valid FIDO2 token data found.");
|
|
|
|
log_info("Automatically discovered security FIDO2 token unlocks volume.");
|
|
|
|
*ret_rp_id = TAKE_PTR(rp);
|
|
*ret_cid = TAKE_PTR(cid);
|
|
*ret_cid_size = cid_size;
|
|
*ret_salt = TAKE_PTR(salt);
|
|
*ret_salt_size = salt_size;
|
|
*ret_keyslot = keyslot;
|
|
*ret_required = required;
|
|
return 0;
|
|
}
|