| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #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 "hostname-util.h" |
| #include "io-util.h" |
| #include "memory-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 "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) { |
| |
| int r; |
| |
| assert(url); |
| assert(etags); |
| |
| if (!image_root) |
| image_root = "/var/lib/machines"; |
| |
| _cleanup_free_ char *escaped_url = xescape(url, FILENAME_ESCAPE); |
| if (!escaped_url) |
| return -ENOMEM; |
| |
| _cleanup_closedir_ DIR *d = opendir(image_root); |
| if (!d) { |
| if (errno == ENOENT) { |
| *etags = NULL; |
| return 0; |
| } |
| |
| return -errno; |
| } |
| |
| _cleanup_strv_free_ char **ans = NULL; |
| |
| FOREACH_DIRENT_ALL(de, d, return -errno) { |
| _cleanup_free_ char *u = NULL; |
| const char *a, *b; |
| |
| 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; |
| |
| ssize_t l = cunescape_length(a, b - a, 0, &u); |
| if (l < 0) { |
| assert(l >= INT8_MIN); |
| return l; |
| } |
| |
| if (!http_etag_is_valid(u)) |
| continue; |
| |
| r = strv_consume(&ans, TAKE_PTR(u)); |
| if (r < 0) |
| return r; |
| } |
| |
| *etags = TAKE_PTR(ans); |
| |
| 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)); |
| 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)); |
| 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, |
| ImportVerify verify, |
| CurlGlue *glue, |
| PullJobOpenDisk on_open_disk, |
| 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_open_disk = on_open_disk; |
| job->on_finished = on_finished; |
| job->compressed_max = job->uncompressed_max = 1ULL * 1024ULL * 1024ULL; |
| job->calc_checksum = IN_SET(verify, IMPORT_VERIFY_CHECKSUM, IMPORT_VERIFY_SIGNATURE); |
| |
| *ret = TAKE_PTR(job); |
| return 0; |
| } |
| |
| static bool is_checksum_file(const char *fn) { |
| /* Returns true if the specified filename refers to a checksum file we grok */ |
| |
| if (!fn) |
| return false; |
| |
| return streq(fn, "SHA256SUMS") || endswith(fn, ".sha256"); |
| } |
| |
| static bool is_signature_file(const char *fn) { |
| /* Returns true if the specified filename refers to a signature file we grok (reminder: |
| * suse-style .sha256 files are inline signed) */ |
| |
| if (!fn) |
| return false; |
| |
| return streq(fn, "SHA256SUMS.gpg") || endswith(fn, ".sha256"); |
| } |
| |
| int pull_make_verification_jobs( |
| PullJob **ret_checksum_job, |
| PullJob **ret_signature_job, |
| ImportVerify verify, |
| const char *checksum, /* set if literal checksum verification is requested, in which case 'verify' is set to _IMPORT_VERIFY_INVALID */ |
| const char *url, |
| CurlGlue *glue, |
| PullJobFinished on_finished, |
| void *userdata) { |
| |
| _cleanup_(pull_job_unrefp) PullJob *checksum_job = NULL, *signature_job = NULL; |
| _cleanup_free_ char *fn = NULL; |
| int r; |
| |
| assert(ret_checksum_job); |
| assert(ret_signature_job); |
| assert(verify == _IMPORT_VERIFY_INVALID || verify < _IMPORT_VERIFY_MAX); |
| assert(verify == _IMPORT_VERIFY_INVALID || verify >= 0); |
| assert((verify < 0) || !checksum); |
| assert(url); |
| assert(glue); |
| |
| /* If verification is turned off, or if the checksum to validate is already specified we don't need |
| * to download a checksum file or signature, hence shortcut things */ |
| if (verify == IMPORT_VERIFY_NO || checksum) { |
| *ret_checksum_job = *ret_signature_job = NULL; |
| return 0; |
| } |
| |
| r = import_url_last_component(url, &fn); |
| if (r < 0 && r != -EADDRNOTAVAIL) /* EADDRNOTAVAIL means there was no last component, which is OK for |
| * us, we'll just assume it's not a checksum/signature file */ |
| return r; |
| |
| /* Acquire the checksum file if verification or signature verification is requested and the main file |
| * to acquire isn't a checksum or signature file anyway */ |
| if (verify != IMPORT_VERIFY_NO && !is_checksum_file(fn) && !is_signature_file(fn)) { |
| _cleanup_free_ char *checksum_url = NULL; |
| const char *suffixed = NULL; |
| |
| /* Queue jobs for the checksum file for the image. */ |
| |
| if (fn) |
| suffixed = strjoina(fn, ".sha256"); /* Start with the suse-style checksum (if there's a base filename) */ |
| else |
| suffixed = "SHA256SUMS"; |
| |
| r = import_url_change_last_component(url, suffixed, &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; |
| checksum_job->on_not_found = pull_job_restart_with_sha256sum; /* if this fails, look for ubuntu-style checksum */ |
| } |
| |
| if (verify == IMPORT_VERIFY_SIGNATURE && !is_signature_file(fn)) { |
| _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 = TAKE_PTR(checksum_job); |
| *ret_signature_job = TAKE_PTR(signature_job); |
| 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_error_errno(r, "Failed to extract filename from URL '%s': %m", job->url); |
| |
| if (!filename_is_valid(fn)) |
| return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), |
| "Cannot verify checksum, could not determine server-side file name."); |
| |
| if (is_checksum_file(fn) || is_signature_file(fn)) /* We cannot verify checksum files or signature files with a checksum file */ |
| return log_error_errno(SYNTHETIC_ERRNO(ELOOP), |
| "Cannot verify checksum/signature files via themselves."); |
| |
| line = strjoina(job->checksum, " *", fn, "\n"); /* string for binary mode */ |
| p = memmem_safe(checksum_job->payload, |
| checksum_job->payload_size, |
| line, |
| strlen(line)); |
| if (!p) { |
| line = strjoina(job->checksum, " ", fn, "\n"); /* string for text mode */ |
| p = memmem_safe(checksum_job->payload, |
| checksum_job->payload_size, |
| line, |
| strlen(line)); |
| } |
| |
| /* Only counts if found at beginning of a line */ |
| if (!p || (p != (char*) checksum_job->payload && p[-1] != '\n')) |
| return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), |
| "DOWNLOAD INVALID: Checksum of %s file did not check out, file has been tampered with.", fn); |
| |
| log_info("SHA256 checksum of %s is valid.", job->url); |
| return 1; |
| } |
| |
| static int verify_gpg( |
| const void *payload, size_t payload_size, |
| const void *signature, size_t signature_size) { |
| |
| _cleanup_close_pair_ int gpg_pipe[2] = PIPE_EBADF; |
| 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(payload || payload_size == 0); |
| assert(signature || signature_size == 0); |
| |
| r = pipe2(gpg_pipe, O_CLOEXEC); |
| if (r < 0) |
| return log_error_errno(errno, "Failed to create pipe for gpg: %m"); |
| |
| if (signature_size > 0) { |
| _cleanup_close_ int sig_file = -EBADF; |
| |
| 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, signature_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 temporary home for gpg: %m"); |
| goto finish; |
| } |
| |
| gpg_home_created = true; |
| |
| r = safe_fork("(gpg)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG|FORK_RLIMIT_NOFILE_SAFE, &pid); |
| if (r < 0) |
| return r; |
| if (r == 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 */ |
| }; |
| size_t k = ELEMENTSOF(cmd) - 6; |
| |
| /* Child */ |
| |
| gpg_pipe[1] = safe_close(gpg_pipe[1]); |
| |
| r = rearrange_stdio(TAKE_FD(gpg_pipe[0]), -EBADF, STDERR_FILENO); |
| if (r < 0) { |
| log_error_errno(r, "Failed to rearrange stdin/stdout: %m"); |
| _exit(EXIT_FAILURE); |
| } |
| |
| 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"; |
| if (signature) { |
| cmd[k++] = sig_file_path; |
| cmd[k++] = "-"; |
| cmd[k++] = NULL; |
| } |
| |
| 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], payload, 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_check("gpg", TAKE_PID(pid), WAIT_LOG_ABNORMAL); |
| if (r < 0) |
| goto finish; |
| if (r != EXIT_SUCCESS) |
| r = log_error_errno(SYNTHETIC_ERRNO(EBADMSG), |
| "DOWNLOAD INVALID: Signature verification failed."); |
| else { |
| log_info("Signature verification succeeded."); |
| r = 0; |
| } |
| |
| finish: |
| if (signature_size > 0) |
| (void) unlink(sig_file_path); |
| |
| if (gpg_home_created) |
| (void) rm_rf(gpg_home, REMOVE_ROOT|REMOVE_PHYSICAL); |
| |
| return r; |
| } |
| |
| int pull_verify(ImportVerify verify, |
| const char *checksum, /* Verify with literal checksum */ |
| PullJob *main_job, |
| PullJob *checksum_job, |
| PullJob *signature_job, |
| PullJob *settings_job, |
| PullJob *roothash_job, |
| PullJob *roothash_signature_job, |
| PullJob *verity_job) { |
| |
| _cleanup_free_ char *fn = NULL; |
| VerificationStyle style; |
| PullJob *verify_job; |
| int r; |
| |
| assert(verify == _IMPORT_VERIFY_INVALID || verify < _IMPORT_VERIFY_MAX); |
| assert(verify == _IMPORT_VERIFY_INVALID || verify >= 0); |
| assert((verify < 0) || !checksum); |
| assert(main_job); |
| assert(main_job->state == PULL_JOB_DONE); |
| |
| if (verify == IMPORT_VERIFY_NO) /* verification turned off */ |
| return 0; |
| |
| if (checksum) { |
| /* Verification by literal checksum */ |
| assert(!checksum_job); |
| assert(!signature_job); |
| assert(!settings_job); |
| assert(!roothash_job); |
| assert(!roothash_signature_job); |
| assert(!verity_job); |
| |
| assert(main_job->calc_checksum); |
| assert(main_job->checksum); |
| |
| if (!strcaseeq(checksum, main_job->checksum)) |
| return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), |
| "DOWNLOAD INVALID: Checksum of %s file did not check out, file has been tampered with.", |
| main_job->url); |
| |
| return 0; |
| } |
| |
| r = import_url_last_component(main_job->url, &fn); |
| if (r < 0) |
| return log_error_errno(r, "Failed to extract filename from URL '%s': %m", main_job->url); |
| |
| if (is_signature_file(fn)) |
| return log_error_errno(SYNTHETIC_ERRNO(ELOOP), |
| "Main download is a signature file, can't verify it."); |
| |
| if (is_checksum_file(fn)) { |
| log_debug("Main download is a checksum file, can't validate its checksum with itself, skipping."); |
| verify_job = main_job; |
| } else { |
| PullJob *j; |
| assert(main_job->calc_checksum); |
| assert(main_job->checksum); |
| assert(checksum_job); |
| assert(checksum_job->state == PULL_JOB_DONE); |
| |
| if (!checksum_job->payload || checksum_job->payload_size <= 0) |
| return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), |
| "Checksum is empty, cannot verify."); |
| |
| FOREACH_POINTER(j, main_job, settings_job, roothash_job, roothash_signature_job, verity_job) { |
| r = verify_one(checksum_job, j); |
| if (r < 0) |
| return r; |
| } |
| |
| verify_job = checksum_job; |
| } |
| |
| if (verify != IMPORT_VERIFY_SIGNATURE) |
| return 0; |
| |
| assert(verify_job); |
| |
| r = verification_style_from_url(verify_job->url, &style); |
| if (r < 0) |
| return log_error_errno(r, "Failed to determine verification style from URL '%s': %m", verify_job->url); |
| |
| if (style == VERIFICATION_PER_DIRECTORY) { |
| assert(signature_job); |
| assert(signature_job->state == PULL_JOB_DONE); |
| |
| if (!signature_job->payload || signature_job->payload_size <= 0) |
| return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), |
| "Signature is empty, cannot verify."); |
| |
| return verify_gpg(verify_job->payload, verify_job->payload_size, signature_job->payload, signature_job->payload_size); |
| } else |
| return verify_gpg(verify_job->payload, verify_job->payload_size, NULL, 0); |
| } |
| |
| int verification_style_from_url(const char *url, VerificationStyle *ret) { |
| _cleanup_free_ char *last = NULL; |
| int r; |
| |
| assert(url); |
| assert(ret); |
| |
| /* Determines which kind of verification style is appropriate for this url */ |
| |
| r = import_url_last_component(url, &last); |
| if (r < 0) |
| return r; |
| |
| if (streq(last, "SHA256SUMS")) { |
| *ret = VERIFICATION_PER_DIRECTORY; |
| return 0; |
| } |
| |
| if (endswith(last, ".sha256")) { |
| *ret = VERIFICATION_PER_FILE; |
| return 0; |
| } |
| |
| return -EINVAL; |
| } |
| |
| int pull_job_restart_with_sha256sum(PullJob *j, char **ret) { |
| VerificationStyle style; |
| int r; |
| |
| assert(j); |
| |
| /* Generic implementation of a PullJobNotFound handler, that restarts the job requesting SHA256SUMS */ |
| |
| r = verification_style_from_url(j->url, &style); |
| if (r < 0) |
| return log_error_errno(r, "Failed to determine verification style of URL '%s': %m", j->url); |
| |
| if (style == VERIFICATION_PER_DIRECTORY) /* Nothing to do anymore */ |
| return 0; |
| |
| assert(style == VERIFICATION_PER_FILE); /* This must have been .sha256 style URL before */ |
| |
| log_debug("Got 404 for %s, now trying to get SHA256SUMS instead.", j->url); |
| |
| r = import_url_change_last_component(j->url, "SHA256SUMS", ret); |
| if (r < 0) |
| return log_error_errno(r, "Failed to replace SHA256SUMS suffix: %m"); |
| |
| return 1; |
| } |
| |
| bool pull_validate_local(const char *name, PullFlags flags) { |
| |
| if (FLAGS_SET(flags, PULL_DIRECT)) |
| return path_is_valid(name); |
| |
| return hostname_is_valid(name, 0); |
| } |
| |
| int pull_url_needs_checksum(const char *url) { |
| _cleanup_free_ char *fn = NULL; |
| int r; |
| |
| /* Returns true if we need to validate this resource via a hash value. This returns true for all |
| * files — except for gpg signature files and SHA256SUMS files and the like, which are validated with |
| * a validation tool like gpg. */ |
| |
| r = import_url_last_component(url, &fn); |
| if (r == -EADDRNOTAVAIL) /* no last component? then let's assume it's not a signature/checksum file */ |
| return false; |
| if (r < 0) |
| return r; |
| |
| return !is_checksum_file(fn) && !is_signature_file(fn); |
| } |
