#include <sys/prctl.h>

#include "alloc-util.h"

#include "btrfs-util.h"

#include "capability-util.h"

#include "copy.h"

#include "dirent-util.h"

#include "escape.h"

#include "fd-util.h"

#include "io-util.h"

#include "path-util.h"

#include "process-util.h"

#include "pull-common.h"

#include "pull-job.h"

#include "rm-rf.h"

#include "signal-util.h"

#include "siphash24.h"

#include "string-util.h"

#include "strv.h"

#include "util.h"

#include "web-util.h"

#define FILENAME_ESCAPE "/.#\"\'"

#define HASH_URL_THRESHOLD_LENGTH (_POSIX_PATH_MAX - 16)

int pull_find_old_etags(

const char *url,

const char *image_root,

int dt,

const char *prefix,

const char *suffix,

char ***etags) {

_cleanup_free_ char *escaped_url = NULL;

_cleanup_closedir_ DIR *d = NULL;

_cleanup_strv_free_ char **l = NULL;

struct dirent *de;

int r;

assert(url);

assert(etags);

if (!image_root)

image_root = "/var/lib/machines";

escaped_url = xescape(url, FILENAME_ESCAPE);

if (!escaped_url)

return -ENOMEM;

d = opendir(image_root);

if (!d) {

if (errno == ENOENT) {

*etags = NULL;

return 0;

}

return -errno;

}

FOREACH_DIRENT_ALL(de, d, return -errno) {

const char *a, *b;

char *u;

if (de->d_type != DT_UNKNOWN &&

de->d_type != dt)

continue;

if (prefix) {

a = startswith(de->d_name, prefix);

if (!a)

continue;

} else

a = de->d_name;

a = startswith(a, escaped_url);

if (!a)

continue;

a = startswith(a, ".");

if (!a)

continue;

if (suffix) {

b = endswith(de->d_name, suffix);

if (!b)

continue;

} else

b = strchr(de->d_name, 0);

if (a >= b)

continue;

r = cunescape_length(a, b - a, 0, &u);

if (r < 0)

return r;

if (!http_etag_is_valid(u)) {

free(u);

continue;

}

r = strv_consume(&l, u);

if (r < 0)

return r;

}

*etags = l;

l = NULL;

return 0;

}

int pull_make_local_copy(const char *final, const char *image_root, const char *local, bool force_local) {

const char *p;

int r;

assert(final);

assert(local);

if (!image_root)

image_root = "/var/lib/machines";

p = strjoina(image_root, "/", local);

if (force_local)

(void) rm_rf(p, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);

r = btrfs_subvol_snapshot(final, p, BTRFS_SNAPSHOT_QUOTA);

if (r == -ENOTTY) {

r = copy_tree(final, p, false);

if (r < 0)

return log_error_errno(r, "Failed to copy image: %m");

} else if (r < 0)

return log_error_errno(r, "Failed to create local image: %m");

log_info("Created new local image '%s'.", local);

return 0;

}

static int hash_url(const char *url, char **ret) {

uint64_t h;

static const sd_id128_t k = SD_ID128_ARRAY(df,89,16,87,01,cc,42,30,98,ab,4a,19,a6,a5,63,4f);

assert(url);

h = siphash24(url, strlen(url), k.bytes);

if (asprintf(ret, "%"PRIx64, h) < 0)

return -ENOMEM;

return 0;

}

int pull_make_path(const char *url, const char *etag, const char *image_root, const char *prefix, const char *suffix, char **ret) {

_cleanup_free_ char *escaped_url = NULL, *escaped_etag = NULL;

char *path;

assert(url);

assert(ret);

if (!image_root)

image_root = "/var/lib/machines";

escaped_url = xescape(url, FILENAME_ESCAPE);

if (!escaped_url)

return -ENOMEM;

if (etag) {

escaped_etag = xescape(etag, FILENAME_ESCAPE);

if (!escaped_etag)

return -ENOMEM;

}

path = strjoin(image_root, "/", strempty(prefix), escaped_url, escaped_etag ? "." : "",

strempty(escaped_etag), strempty(suffix), NULL);

if (!path)

return -ENOMEM;

/* URLs might make the path longer than the maximum allowed length for a file name.

if (strlen(path) >= HASH_URL_THRESHOLD_LENGTH) {

_cleanup_free_ char *hash = NULL;

int r;

free(path);

r = hash_url(url, &hash);

if (r < 0)

return r;

path = strjoin(image_root, "/", strempty(prefix), hash, escaped_etag ? "." : "",

strempty(escaped_etag), strempty(suffix), NULL);

if (!path)

return -ENOMEM;

}

*ret = path;

return 0;

}

int pull_make_settings_job(

PullJob **ret,

const char *url,

CurlGlue *glue,

PullJobFinished on_finished,

void *userdata) {

_cleanup_free_ char *last_component = NULL, *ll = NULL, *settings_url = NULL;

_cleanup_(pull_job_unrefp) PullJob *job = NULL;

const char *q;

int r;

assert(ret);

assert(url);

assert(glue);

r = import_url_last_component(url, &last_component);

if (r < 0)

return r;

r = tar_strip_suffixes(last_component, &ll);

if (r < 0)

return r;

q = strjoina(ll, ".nspawn");

r = import_url_change_last_component(url, q, &settings_url);

if (r < 0)

return r;

r = pull_job_new(&job, settings_url, glue, userdata);

if (r < 0)

return r;

job->on_finished = on_finished;

job->compressed_max = job->uncompressed_max = 1ULL * 1024ULL * 1024ULL;

*ret = job;

job = NULL;

return 0;

}

int pull_make_verification_jobs(

PullJob **ret_checksum_job,

PullJob **ret_signature_job,

ImportVerify verify,

const char *url,

CurlGlue *glue,

PullJobFinished on_finished,

void *userdata) {

_cleanup_(pull_job_unrefp) PullJob *checksum_job = NULL, *signature_job = NULL;

int r;

assert(ret_checksum_job);

assert(ret_signature_job);

assert(verify >= 0);

assert(verify < _IMPORT_VERIFY_MAX);

assert(url);

assert(glue);

if (verify != IMPORT_VERIFY_NO) {

_cleanup_free_ char *checksum_url = NULL;

/* Queue job for the SHA256SUMS file for the image */

r = import_url_change_last_component(url, "SHA256SUMS", &checksum_url);

if (r < 0)

return r;

r = pull_job_new(&checksum_job, checksum_url, glue, userdata);

if (r < 0)

return r;

checksum_job->on_finished = on_finished;

checksum_job->uncompressed_max = checksum_job->compressed_max = 1ULL * 1024ULL * 1024ULL;

}

if (verify == IMPORT_VERIFY_SIGNATURE) {

_cleanup_free_ char *signature_url = NULL;

/* Queue job for the SHA256SUMS.gpg file for the image. */

r = import_url_change_last_component(url, "SHA256SUMS.gpg", &signature_url);

if (r < 0)

return r;

r = pull_job_new(&signature_job, signature_url, glue, userdata);

if (r < 0)

return r;

signature_job->on_finished = on_finished;

signature_job->uncompressed_max = signature_job->compressed_max = 1ULL * 1024ULL * 1024ULL;

}

*ret_checksum_job = checksum_job;

*ret_signature_job = signature_job;

checksum_job = signature_job = NULL;

return 0;

}

int pull_verify(PullJob *main_job,

PullJob *settings_job,

PullJob *checksum_job,

PullJob *signature_job) {

_cleanup_close_pair_ int gpg_pipe[2] = { -1, -1 };

_cleanup_free_ char *fn = NULL;

_cleanup_close_ int sig_file = -1;

const char *p, *line;

char sig_file_path[] = "/tmp/sigXXXXXX", gpg_home[] = "/tmp/gpghomeXXXXXX";

_cleanup_sigkill_wait_ pid_t pid = 0;

bool gpg_home_created = false;

int r;

assert(main_job);

assert(main_job->state == PULL_JOB_DONE);

if (!checksum_job)

return 0;

assert(main_job->calc_checksum);

assert(main_job->checksum);

assert(checksum_job->state == PULL_JOB_DONE);

if (!checksum_job->payload || checksum_job->payload_size <= 0) {

log_error("Checksum is empty, cannot verify.");

return -EBADMSG;

}

r = import_url_last_component(main_job->url, &fn);

if (r < 0)

return log_oom();

if (!filename_is_valid(fn)) {

log_error("Cannot verify checksum, could not determine valid server-side file name.");

return -EBADMSG;

}

line = strjoina(main_job->checksum, " *", fn, "\n");

p = memmem(checksum_job->payload,

checksum_job->payload_size,

line,

strlen(line));

if (!p || (p != (char*) checksum_job->payload && p[-1] != '\n')) {

log_error("DOWNLOAD INVALID: Checksum did not check out, payload has been tampered with.");

return -EBADMSG;

}

log_info("SHA256 checksum of %s is valid.", main_job->url);

assert(!settings_job || IN_SET(settings_job->state, PULL_JOB_DONE, PULL_JOB_FAILED));

if (settings_job &&

settings_job->state == PULL_JOB_DONE &&

settings_job->error == 0 &&

!settings_job->etag_exists) {

_cleanup_free_ char *settings_fn = NULL;

assert(settings_job->calc_checksum);

assert(settings_job->checksum);

r = import_url_last_component(settings_job->url, &settings_fn);

if (r < 0)

return log_oom();

if (!filename_is_valid(settings_fn)) {

log_error("Cannot verify checksum, could not determine server-side settings file name.");

return -EBADMSG;

}

line = strjoina(settings_job->checksum, " *", settings_fn, "\n");

p = memmem(checksum_job->payload,

checksum_job->payload_size,

line,

strlen(line));

if (!p || (p != (char*) checksum_job->payload && p[-1] != '\n')) {

log_error("DOWNLOAD INVALID: Checksum of settings file did not checkout, settings file has been tampered with.");

return -EBADMSG;

}

log_info("SHA256 checksum of %s is valid.", settings_job->url);

}

if (!signature_job)

return 0;

assert(signature_job->state == PULL_JOB_DONE);

if (!signature_job->payload || signature_job->payload_size <= 0) {

log_error("Signature is empty, cannot verify.");

return -EBADMSG;

}

r = pipe2(gpg_pipe, O_CLOEXEC);

if (r < 0)

return log_error_errno(errno, "Failed to create pipe for gpg: %m");

sig_file = mkostemp(sig_file_path, O_RDWR);

if (sig_file < 0)

return log_error_errno(errno, "Failed to create temporary file: %m");

r = loop_write(sig_file, signature_job->payload, signature_job->payload_size, false);

if (r < 0) {

log_error_errno(r, "Failed to write to temporary file: %m");

goto finish;

}

if (!mkdtemp(gpg_home)) {

r = log_error_errno(errno, "Failed to create tempory home for gpg: %m");

goto finish;

}

gpg_home_created = true;

pid = fork();

if (pid < 0)

return log_error_errno(errno, "Failed to fork off gpg: %m");

if (pid == 0) {

const char *cmd[] = {

"gpg",

"--no-options",

"--no-default-keyring",

"--no-auto-key-locate",

"--no-auto-check-trustdb",

"--batch",

"--trust-model=always",

NULL, /* --homedir= */

NULL, /* --keyring= */

NULL, /* --verify */

NULL, /* signature file */

NULL, /* dash */

NULL /* trailing NULL */

};

unsigned k = ELEMENTSOF(cmd) - 6;

int null_fd;

/* Child */

(void) reset_all_signal_handlers();

(void) reset_signal_mask();

assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);

gpg_pipe[1] = safe_close(gpg_pipe[1]);

if (dup2(gpg_pipe[0], STDIN_FILENO) != STDIN_FILENO) {

log_error_errno(errno, "Failed to dup2() fd: %m");

_exit(EXIT_FAILURE);

}

if (gpg_pipe[0] != STDIN_FILENO)

gpg_pipe[0] = safe_close(gpg_pipe[0]);

null_fd = open("/dev/null", O_WRONLY|O_NOCTTY);

if (null_fd < 0) {

log_error_errno(errno, "Failed to open /dev/null: %m");

_exit(EXIT_FAILURE);

}

if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) {

log_error_errno(errno, "Failed to dup2() fd: %m");

_exit(EXIT_FAILURE);

}

if (null_fd != STDOUT_FILENO)

null_fd = safe_close(null_fd);

cmd[k++] = strjoina("--homedir=", gpg_home);

/* We add the user keyring only to the command line

if (access(USER_KEYRING_PATH, F_OK) >= 0)

cmd[k++] = "--keyring=" USER_KEYRING_PATH;

else

cmd[k++] = "--keyring=" VENDOR_KEYRING_PATH;

cmd[k++] = "--verify";

cmd[k++] = sig_file_path;

cmd[k++] = "-";

cmd[k++] = NULL;

fd_cloexec(STDIN_FILENO, false);

fd_cloexec(STDOUT_FILENO, false);

fd_cloexec(STDERR_FILENO, false);

execvp("gpg2", (char * const *) cmd);

execvp("gpg", (char * const *) cmd);

log_error_errno(errno, "Failed to execute gpg: %m");

_exit(EXIT_FAILURE);

}

gpg_pipe[0] = safe_close(gpg_pipe[0]);

r = loop_write(gpg_pipe[1], checksum_job->payload, checksum_job->payload_size, false);

if (r < 0) {

log_error_errno(r, "Failed to write to pipe: %m");

goto finish;

}

gpg_pipe[1] = safe_close(gpg_pipe[1]);

r = wait_for_terminate_and_warn("gpg", pid, true);

pid = 0;

if (r < 0)

goto finish;

if (r > 0) {

log_error("DOWNLOAD INVALID: Signature verification failed.");

r = -EBADMSG;

} else {

log_info("Signature verification succeeded.");

r = 0;

}

finish:

if (sig_file >= 0)

(void) unlink(sig_file_path);

if (gpg_home_created)

(void) rm_rf(gpg_home, REMOVE_ROOT|REMOVE_PHYSICAL);

return r;

}