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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "ask-password-api.h"
#include "cryptenroll-fido2.h"
#include "cryptsetup-fido2.h"
#include "hexdecoct.h"
#include "json.h"
#include "libfido2-util.h"
#include "memory-util.h"
#include "random-util.h"
int load_volume_key_fido2(
struct crypt_device *cd,
const char *cd_node,
const char *device,
void *ret_vk,
size_t *ret_vks) {
_cleanup_(erase_and_freep) void *decrypted_key = NULL;
_cleanup_(erase_and_freep) char *passphrase = NULL;
size_t decrypted_key_size;
ssize_t passphrase_size;
int r;
assert_se(cd);
assert_se(cd_node);
assert_se(ret_vk);
assert_se(ret_vks);
r = acquire_fido2_key_auto(
cd,
cd_node,
cd_node,
device,
/* until= */ 0,
"cryptenroll.fido2-pin",
ASK_PASSWORD_PUSH_CACHE|ASK_PASSWORD_ACCEPT_CACHED,
&decrypted_key,
&decrypted_key_size);
if (r == -EAGAIN)
return log_error_errno(r, "FIDO2 token does not exist, or UV is blocked. Please try again.");
if (r < 0)
return r;
/* Because cryptenroll requires a LUKS header, we can assume that this device is not
* a PLAIN device. In this case, we need to base64 encode the secret to use as the passphrase */
passphrase_size = base64mem(decrypted_key, decrypted_key_size, &passphrase);
if (passphrase_size < 0)
return log_oom();
r = crypt_volume_key_get(
cd,
CRYPT_ANY_SLOT,
ret_vk,
ret_vks,
passphrase,
passphrase_size);
if (r < 0)
return log_error_errno(r, "Unlocking via FIDO2 device failed: %m");
return r;
}
int enroll_fido2(
struct crypt_device *cd,
const void *volume_key,
size_t volume_key_size,
const char *device,
Fido2EnrollFlags lock_with,
int cred_alg) {
_cleanup_(erase_and_freep) void *salt = NULL, *secret = NULL;
_cleanup_(erase_and_freep) char *base64_encoded = NULL;
_cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
_cleanup_free_ char *keyslot_as_string = NULL;
size_t cid_size, salt_size, secret_size;
_cleanup_free_ void *cid = NULL;
ssize_t base64_encoded_size;
const char *node, *un;
int r, keyslot;
assert_se(cd);
assert_se(volume_key);
assert_se(volume_key_size > 0);
assert_se(device);
assert_se(node = crypt_get_device_name(cd));
un = strempty(crypt_get_uuid(cd));
r = fido2_generate_hmac_hash(
device,
/* rp_id= */ "io.systemd.cryptsetup",
/* rp_name= */ "Encrypted Volume",
/* user_id= */ un, strlen(un), /* We pass the user ID and name as the same: the disk's UUID if we have it */
/* user_name= */ un,
/* user_display_name= */ node,
/* user_icon_name= */ NULL,
/* askpw_icon_name= */ "drive-harddisk",
/* askpw_credential= */ "cryptenroll.fido2-pin",
lock_with,
cred_alg,
&cid, &cid_size,
&salt, &salt_size,
&secret, &secret_size,
NULL,
&lock_with);
if (r < 0)
return r;
/* Before we use the secret, we base64 encode it, for compat with homed, and to make it easier to type in manually */
base64_encoded_size = base64mem(secret, secret_size, &base64_encoded);
if (base64_encoded_size < 0)
return log_error_errno(base64_encoded_size, "Failed to base64 encode secret key: %m");
r = cryptsetup_set_minimal_pbkdf(cd);
if (r < 0)
return log_error_errno(r, "Failed to set minimal PBKDF: %m");
keyslot = crypt_keyslot_add_by_volume_key(
cd,
CRYPT_ANY_SLOT,
volume_key,
volume_key_size,
base64_encoded,
base64_encoded_size);
if (keyslot < 0)
return log_error_errno(keyslot, "Failed to add new FIDO2 key to %s: %m", node);
if (asprintf(&keyslot_as_string, "%i", keyslot) < 0)
return log_oom();
r = json_build(&v,
JSON_BUILD_OBJECT(
JSON_BUILD_PAIR("type", JSON_BUILD_CONST_STRING("systemd-fido2")),
JSON_BUILD_PAIR("keyslots", JSON_BUILD_ARRAY(JSON_BUILD_STRING(keyslot_as_string))),
JSON_BUILD_PAIR("fido2-credential", JSON_BUILD_BASE64(cid, cid_size)),
JSON_BUILD_PAIR("fido2-salt", JSON_BUILD_BASE64(salt, salt_size)),
JSON_BUILD_PAIR("fido2-rp", JSON_BUILD_CONST_STRING("io.systemd.cryptsetup")),
JSON_BUILD_PAIR("fido2-clientPin-required", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_PIN))),
JSON_BUILD_PAIR("fido2-up-required", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_UP))),
JSON_BUILD_PAIR("fido2-uv-required", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_UV)))));
if (r < 0)
return log_error_errno(r, "Failed to prepare FIDO2 JSON token object: %m");
r = cryptsetup_add_token_json(cd, v);
if (r < 0)
return log_error_errno(r, "Failed to add FIDO2 JSON token to LUKS2 header: %m");
log_info("New FIDO2 token enrolled as key slot %i.", keyslot);
return keyslot;
}
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