Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 669 insertions, 0 deletions

diff --git a/src/import/pull-common.c b/src/import/pull-common.c
new file mode 100644
index 0000000..5e1ea20
--- /dev/null
+++ b/src/import/pull-common.c
@@ -0,0 +1,669 @@
+/* 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] = EBADF_PAIR;
+        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);
+                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_full("(gpg)",
+                           (int[]) { gpg_pipe[0], -EBADF, STDERR_FILENO },
+                           NULL, 0,
+                           FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG_SIGTERM|FORK_REARRANGE_STDIO|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 */
+
+                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);
+        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);
+}