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-rw-r--r--src/import/pull-common.c677
1 files changed, 677 insertions, 0 deletions
diff --git a/src/import/pull-common.c b/src/import/pull-common.c
new file mode 100644
index 0000000..028bae8
--- /dev/null
+++ b/src/import/pull-common.c
@@ -0,0 +1,677 @@
+/* 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 "rlimit-util.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) {
+
+ 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] = { -1, -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(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 = -1;
+
+ 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, &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]), -1, STDERR_FILENO);
+ if (r < 0) {
+ log_error_errno(r, "Failed to rearrange stdin/stdout: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ (void) rlimit_nofile_safe();
+
+ 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);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-29 23:29:59 +0000