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mirror of https://github.com/systemd/systemd-stable.git synced 2025-01-20 14:03:39 +03:00

bootctl: split out setting of system token into function of its own

Let's break a huge function in two. No code change, just some
refactoring.
This commit is contained in:
Lennart Poettering 2022-12-20 18:03:06 +01:00
parent 921fc451cb
commit 54978e3f3b

View File

@ -17,12 +17,79 @@
#include "tmpfile-util.h"
#include "umask-util.h"
static int set_system_token(void) {
uint8_t buffer[RANDOM_EFI_SEED_SIZE];
size_t token_size;
int r;
if (!arg_touch_variables)
return 0;
if (arg_root) {
log_warning("Acting on %s, skipping EFI variable setup.",
arg_image ? "image" : "root directory");
return 0;
}
if (!is_efi_boot()) {
log_notice("Not booted with EFI, skipping EFI variable setup.");
return 0;
}
r = getenv_bool("SYSTEMD_WRITE_SYSTEM_TOKEN");
if (r < 0) {
if (r != -ENXIO)
log_warning_errno(r, "Failed to parse $SYSTEMD_WRITE_SYSTEM_TOKEN, ignoring.");
} else if (r == 0) {
log_notice("Not writing system token, because $SYSTEMD_WRITE_SYSTEM_TOKEN is set to false.");
return 0;
}
r = efi_get_variable(EFI_LOADER_VARIABLE(LoaderSystemToken), NULL, NULL, &token_size);
if (r == -ENODATA)
log_debug_errno(r, "LoaderSystemToken EFI variable is invalid (too short?), replacing.");
else if (r < 0) {
if (r != -ENOENT)
return log_error_errno(r, "Failed to test system token validity: %m");
} else {
if (token_size >= sizeof(buffer)) {
/* Let's avoid writes if we can, and initialize this only once. */
log_debug("System token already written, not updating.");
return 0;
}
log_debug("Existing system token size (%zu) does not match our expectations (%zu), replacing.", token_size, sizeof(buffer));
}
r = crypto_random_bytes(buffer, sizeof(buffer));
if (r < 0)
return log_error_errno(r, "Failed to acquire random seed: %m");
/* Let's write this variable with an umask in effect, so that unprivileged users can't see the token
* and possibly get identification information or too much insight into the kernel's entropy pool
* state. */
WITH_UMASK(0077) {
r = efi_set_variable(EFI_LOADER_VARIABLE(LoaderSystemToken), buffer, sizeof(buffer));
if (r < 0) {
if (!arg_graceful)
return log_error_errno(r, "Failed to write 'LoaderSystemToken' EFI variable: %m");
if (r == -EINVAL)
log_notice_errno(r, "Unable to write 'LoaderSystemToken' EFI variable (firmware problem?), ignoring: %m");
else
log_notice_errno(r, "Unable to write 'LoaderSystemToken' EFI variable, ignoring: %m");
} else
log_info("Successfully initialized system token in EFI variable with %zu bytes.", sizeof(buffer));
}
return 0;
}
int install_random_seed(const char *esp) {
_cleanup_close_ int esp_fd = -EBADF, loader_dir_fd = -EBADF, fd = -EBADF;
_cleanup_free_ char *tmp = NULL;
uint8_t buffer[RANDOM_EFI_SEED_SIZE];
struct sha256_ctx hash_state;
size_t token_size;
bool refreshed;
int r;
@ -99,67 +166,7 @@ int install_random_seed(const char *esp) {
log_info("Random seed file %s/loader/random-seed successfully %s (%zu bytes).", esp, refreshed ? "refreshed" : "written", sizeof(buffer));
if (!arg_touch_variables)
return 0;
if (arg_root) {
log_warning("Acting on %s, skipping EFI variable setup.",
arg_image ? "image" : "root directory");
return 0;
}
if (!is_efi_boot()) {
log_notice("Not booted with EFI, skipping EFI variable setup.");
return 0;
}
r = getenv_bool("SYSTEMD_WRITE_SYSTEM_TOKEN");
if (r < 0) {
if (r != -ENXIO)
log_warning_errno(r, "Failed to parse $SYSTEMD_WRITE_SYSTEM_TOKEN, ignoring.");
} else if (r == 0) {
log_notice("Not writing system token, because $SYSTEMD_WRITE_SYSTEM_TOKEN is set to false.");
return 0;
}
r = efi_get_variable(EFI_LOADER_VARIABLE(LoaderSystemToken), NULL, NULL, &token_size);
if (r == -ENODATA)
log_debug_errno(r, "LoaderSystemToken EFI variable is invalid (too short?), replacing.");
else if (r < 0) {
if (r != -ENOENT)
return log_error_errno(r, "Failed to test system token validity: %m");
} else {
if (token_size >= sizeof(buffer)) {
/* Let's avoid writes if we can, and initialize this only once. */
log_debug("System token already written, not updating.");
return 0;
}
log_debug("Existing system token size (%zu) does not match our expectations (%zu), replacing.", token_size, sizeof(buffer));
}
r = crypto_random_bytes(buffer, sizeof(buffer));
if (r < 0)
return log_error_errno(r, "Failed to acquire random seed: %m");
/* Let's write this variable with an umask in effect, so that unprivileged users can't see the token
* and possibly get identification information or too much insight into the kernel's entropy pool
* state. */
WITH_UMASK(0077) {
r = efi_set_variable(EFI_LOADER_VARIABLE(LoaderSystemToken), buffer, sizeof(buffer));
if (r < 0) {
if (!arg_graceful)
return log_error_errno(r, "Failed to write 'LoaderSystemToken' EFI variable: %m");
if (r == -EINVAL)
log_notice_errno(r, "Unable to write 'LoaderSystemToken' EFI variable (firmware problem?), ignoring: %m");
else
log_notice_errno(r, "Unable to write 'LoaderSystemToken' EFI variable, ignoring: %m");
} else
log_info("Successfully initialized system token in EFI variable with %zu bytes.", sizeof(buffer));
}
return 0;
return set_system_token();
fail:
if (tmp)