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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#if HAVE_LIBFIDO2
#include <fido.h>
#endif
#include "ask-password-api.h"
#include "errno-util.h"
#include "format-table.h"
#include "hexdecoct.h"
#include "homectl-fido2.h"
#include "homectl-pkcs11.h"
#include "libcrypt-util.h"
#include "libfido2-util.h"
#include "locale-util.h"
#include "memory-util.h"
#include "random-util.h"
#include "strv.h"
#if HAVE_LIBFIDO2
static int add_fido2_credential_id(
JsonVariant **v,
const void *cid,
size_t cid_size) {
_cleanup_(json_variant_unrefp) JsonVariant *w = NULL;
_cleanup_strv_free_ char **l = NULL;
_cleanup_free_ char *escaped = NULL;
ssize_t escaped_size;
int r;
assert(v);
assert(cid);
escaped_size = base64mem(cid, cid_size, &escaped);
if (escaped_size < 0)
return log_error_errno(escaped_size, "Failed to base64 encode FIDO2 credential ID: %m");
w = json_variant_ref(json_variant_by_key(*v, "fido2HmacCredential"));
if (w) {
r = json_variant_strv(w, &l);
if (r < 0)
return log_error_errno(r, "Failed to parse FIDO2 credential ID list: %m");
if (strv_contains(l, escaped))
return 0;
}
r = strv_extend(&l, escaped);
if (r < 0)
return log_oom();
w = json_variant_unref(w);
r = json_variant_new_array_strv(&w, l);
if (r < 0)
return log_error_errno(r, "Failed to create FIDO2 credential ID JSON: %m");
r = json_variant_set_field(v, "fido2HmacCredential", w);
if (r < 0)
return log_error_errno(r, "Failed to update FIDO2 credential ID: %m");
return 0;
}
static int add_fido2_salt(
JsonVariant **v,
const void *cid,
size_t cid_size,
const void *fido2_salt,
size_t fido2_salt_size,
const void *secret,
size_t secret_size,
Fido2EnrollFlags lock_with) {
_cleanup_(json_variant_unrefp) JsonVariant *l = NULL, *w = NULL, *e = NULL;
_cleanup_(erase_and_freep) char *base64_encoded = NULL, *hashed = NULL;
ssize_t base64_encoded_size;
int r;
/* Before using UNIX hashing on the supplied key we base64 encode it, since crypt_r() and friends
* expect a NUL terminated string, and we use a binary key */
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 = hash_password(base64_encoded, &hashed);
if (r < 0)
return log_error_errno(errno_or_else(EINVAL), "Failed to UNIX hash secret key: %m");
r = json_build(&e, JSON_BUILD_OBJECT(
JSON_BUILD_PAIR("credential", JSON_BUILD_BASE64(cid, cid_size)),
JSON_BUILD_PAIR("salt", JSON_BUILD_BASE64(fido2_salt, fido2_salt_size)),
JSON_BUILD_PAIR("hashedPassword", JSON_BUILD_STRING(hashed)),
JSON_BUILD_PAIR("up", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_UP))),
JSON_BUILD_PAIR("uv", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_UV))),
JSON_BUILD_PAIR("clientPin", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_PIN)))));
if (r < 0)
return log_error_errno(r, "Failed to build FIDO2 salt JSON key object: %m");
w = json_variant_ref(json_variant_by_key(*v, "privileged"));
l = json_variant_ref(json_variant_by_key(w, "fido2HmacSalt"));
r = json_variant_append_array(&l, e);
if (r < 0)
return log_error_errno(r, "Failed append FIDO2 salt: %m");
r = json_variant_set_field(&w, "fido2HmacSalt", l);
if (r < 0)
return log_error_errno(r, "Failed to set FDO2 salt: %m");
r = json_variant_set_field(v, "privileged", w);
if (r < 0)
return log_error_errno(r, "Failed to update privileged field: %m");
return 0;
}
#endif
int identity_add_fido2_parameters(
JsonVariant **v,
const char *device,
Fido2EnrollFlags lock_with,
int cred_alg) {
#if HAVE_LIBFIDO2
JsonVariant *un, *realm, *rn;
_cleanup_(erase_and_freep) void *secret = NULL, *salt = NULL;
_cleanup_(erase_and_freep) char *used_pin = NULL;
size_t cid_size, salt_size, secret_size;
_cleanup_free_ void *cid = NULL;
const char *fido_un;
int r;
assert(v);
assert(device);
un = json_variant_by_key(*v, "userName");
if (!un)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"userName field of user record is missing");
if (!json_variant_is_string(un))
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"userName field of user record is not a string");
realm = json_variant_by_key(*v, "realm");
if (realm) {
if (!json_variant_is_string(realm))
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"realm field of user record is not a string");
fido_un = strjoina(json_variant_string(un), json_variant_string(realm));
} else
fido_un = json_variant_string(un);
rn = json_variant_by_key(*v, "realName");
if (rn && !json_variant_is_string(rn))
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"realName field of user record is not a string");
r = fido2_generate_hmac_hash(
device,
/* rp_id= */ "io.systemd.home",
/* rp_name= */ "Home Directory",
/* user_id= */ fido_un, strlen(fido_un), /* We pass the user ID and name as the same */
/* user_name= */ fido_un,
/* user_display_name= */ rn ? json_variant_string(rn) : NULL,
/* user_icon_name= */ NULL,
/* askpw_icon_name= */ "user-home",
/* askpw_credential= */ "home.token-pin",
lock_with,
cred_alg,
&cid, &cid_size,
&salt, &salt_size,
&secret, &secret_size,
&used_pin,
&lock_with);
if (r < 0)
return r;
r = add_fido2_credential_id(
v,
cid,
cid_size);
if (r < 0)
return r;
r = add_fido2_salt(
v,
cid,
cid_size,
salt,
salt_size,
secret,
secret_size,
lock_with);
if (r < 0)
return r;
/* If we acquired the PIN also include it in the secret section of the record, so that systemd-homed
* can use it if it needs to, given that it likely needs to decrypt the key again to pass to LUKS or
* fscrypt. */
r = identity_add_token_pin(v, used_pin);
if (r < 0)
return r;
return 0;
#else
return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
"FIDO2 tokens not supported on this build.");
#endif
}
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