| /*** |
| This file is part of systemd. |
| |
| Copyright 2015 Lennart Poettering |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #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| |
| BTRFS_SNAPSHOT_FALLBACK_COPY| |
| BTRFS_SNAPSHOT_FALLBACK_DIRECTORY| |
| BTRFS_SNAPSHOT_RECURSIVE); |
| 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. |
| * When that happens, a URL hash is used instead. Paths returned by this function |
| * can be later used with tempfn_random() which adds 16 bytes to the resulting 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_auxiliary_job( |
| PullJob **ret, |
| const char *url, |
| int (*strip_suffixes)(const char *name, char **ret), |
| const char *suffix, |
| CurlGlue *glue, |
| PullJobFinished on_finished, |
| void *userdata) { |
| |
| _cleanup_free_ char *last_component = NULL, *ll = NULL, *auxiliary_url = NULL; |
| _cleanup_(pull_job_unrefp) PullJob *job = NULL; |
| const char *q; |
| int r; |
| |
| assert(ret); |
| assert(url); |
| assert(strip_suffixes); |
| assert(glue); |
| |
| r = import_url_last_component(url, &last_component); |
| if (r < 0) |
| return r; |
| |
| r = strip_suffixes(last_component, &ll); |
| if (r < 0) |
| return r; |
| |
| q = strjoina(ll, suffix); |
| |
| r = import_url_change_last_component(url, q, &auxiliary_url); |
| if (r < 0) |
| return r; |
| |
| r = pull_job_new(&job, auxiliary_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; |
| } |
| |
| static int verify_one(PullJob *checksum_job, PullJob *job) { |
| _cleanup_free_ char *fn = NULL; |
| const char *line, *p; |
| int r; |
| |
| assert(checksum_job); |
| |
| if (!job) |
| return 0; |
| |
| assert(IN_SET(job->state, PULL_JOB_DONE, PULL_JOB_FAILED)); |
| |
| /* Don't verify the checksum if we didn't actually successfully download something new */ |
| if (job->state != PULL_JOB_DONE) |
| return 0; |
| if (job->error != 0) |
| return 0; |
| if (job->etag_exists) |
| return 0; |
| |
| assert(job->calc_checksum); |
| assert(job->checksum); |
| |
| r = import_url_last_component(job->url, &fn); |
| if (r < 0) |
| return log_oom(); |
| |
| if (!filename_is_valid(fn)) { |
| log_error("Cannot verify checksum, could not determine server-side file name."); |
| return -EBADMSG; |
| } |
| |
| line = strjoina(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 of %s file did not checkout, file has been tampered with.", fn); |
| return -EBADMSG; |
| } |
| |
| log_info("SHA256 checksum of %s is valid.", job->url); |
| return 1; |
| } |
| |
| int pull_verify(PullJob *main_job, |
| PullJob *roothash_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; |
| char sig_file_path[] = "/tmp/sigXXXXXX", gpg_home[] = "/tmp/gpghomeXXXXXX"; |
| _cleanup_(sigkill_waitp) 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 = verify_one(checksum_job, main_job); |
| if (r < 0) |
| return r; |
| |
| r = verify_one(checksum_job, roothash_job); |
| if (r < 0) |
| return r; |
| |
| r = verify_one(checksum_job, settings_job); |
| if (r < 0) |
| return r; |
| |
| 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 |
| * arguments, if it's around since gpg fails |
| * otherwise. */ |
| 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; |
| |
| stdio_unset_cloexec(); |
| |
| 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; |
| } |