more

3 files changed, 248 insertions, 0 deletions

diff --git a/src/grp-initprogs/systemd-random-seed/Makefile b/src/grp-initprogs/systemd-random-seed/Makefile
new file mode 100644
index 0000000000..489a8ab007
--- /dev/null
+++ b/src/grp-initprogs/systemd-random-seed/Makefile
@@ -0,0 +1,50 @@
+#  -*- Mode: makefile; indent-tabs-mode: t -*-
+#
+#  This file is part of systemd.
+#
+#  Copyright 2010-2012 Lennart Poettering
+#  Copyright 2010-2012 Kay Sievers
+#  Copyright 2013 Zbigniew Jędrzejewski-Szmek
+#  Copyright 2013 David Strauss
+#  Copyright 2016 Luke Shumaker
+#
+#  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 $(dir $(lastword $(MAKEFILE_LIST)))/../../../config.mk
+include $(topsrcdir)/build-aux/Makefile.head.mk
+
+ifneq ($(ENABLE_RANDOMSEED),)
+rootlibexec_PROGRAMS += \
+	systemd-random-seed
+
+nodist_systemunit_DATA += \
+	units/systemd-random-seed.service
+
+systemd_random_seed_SOURCES = \
+	src/random-seed/random-seed.c
+
+systemd_random_seed_LDADD = \
+	libshared.la
+
+SYSINIT_TARGET_WANTS += \
+	systemd-random-seed.service
+
+endif # ENABLE_RANDOMSEED
+
+EXTRA_DIST += \
+	units/systemd-random-seed.service.in
+
+sd.CPPFLAGS += -DRANDOM_SEED_DIR=\"$(localstatedir)/lib/systemd/\"
+sd.CPPFLAGS += -DRANDOM_SEED=\"$(localstatedir)/lib/systemd/random-seed\"
+
+include $(topsrcdir)/build-aux/Makefile.tail.mk
diff --git a/src/grp-initprogs/systemd-random-seed/random-seed.c b/src/grp-initprogs/systemd-random-seed/random-seed.c
new file mode 100644
index 0000000000..7fea6069f3
--- /dev/null
+++ b/src/grp-initprogs/systemd-random-seed/random-seed.c
@@ -0,0 +1,176 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2010 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 <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "basic/alloc-util.h"
+#include "basic/fd-util.h"
+#include "basic/io-util.h"
+#include "basic/log.h"
+#include "basic/mkdir.h"
+#include "basic/string-util.h"
+#include "basic/util.h"
+
+#define POOL_SIZE_MIN 512
+
+int main(int argc, char *argv[]) {
+        _cleanup_close_ int seed_fd = -1, random_fd = -1;
+        _cleanup_free_ void* buf = NULL;
+        size_t buf_size = 0;
+        ssize_t k;
+        int r, open_rw_error;
+        FILE *f;
+        bool refresh_seed_file = true;
+
+        if (argc != 2) {
+                log_error("This program requires one argument.");
+                return EXIT_FAILURE;
+        }
+
+        log_set_target(LOG_TARGET_AUTO);
+        log_parse_environment();
+        log_open();
+
+        umask(0022);
+
+        /* Read pool size, if possible */
+        f = fopen("/proc/sys/kernel/random/poolsize", "re");
+        if (f) {
+                if (fscanf(f, "%zu", &buf_size) > 0)
+                        /* poolsize is in bits on 2.6, but we want bytes */
+                        buf_size /= 8;
+
+                fclose(f);
+        }
+
+        if (buf_size <= POOL_SIZE_MIN)
+                buf_size = POOL_SIZE_MIN;
+
+        buf = malloc(buf_size);
+        if (!buf) {
+                r = log_oom();
+                goto finish;
+        }
+
+        r = mkdir_parents_label(RANDOM_SEED, 0755);
+        if (r < 0) {
+                log_error_errno(r, "Failed to create directory " RANDOM_SEED_DIR ": %m");
+                goto finish;
+        }
+
+        /* When we load the seed we read it and write it to the device
+         * and then immediately update the saved seed with new data,
+         * to make sure the next boot gets seeded differently. */
+
+        if (streq(argv[1], "load")) {
+
+                seed_fd = open(RANDOM_SEED, O_RDWR|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600);
+                open_rw_error = -errno;
+                if (seed_fd < 0) {
+                        refresh_seed_file = false;
+
+                        seed_fd = open(RANDOM_SEED, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+                        if (seed_fd < 0) {
+                                bool missing = errno == ENOENT;
+
+                                log_full_errno(missing ? LOG_DEBUG : LOG_ERR,
+                                               open_rw_error, "Failed to open " RANDOM_SEED " for writing: %m");
+                                r = log_full_errno(missing ? LOG_DEBUG : LOG_ERR,
+                                                   errno, "Failed to open " RANDOM_SEED " for reading: %m");
+                                if (missing)
+                                        r = 0;
+
+                                goto finish;
+                        }
+                }
+
+                random_fd = open("/dev/urandom", O_RDWR|O_CLOEXEC|O_NOCTTY, 0600);
+                if (random_fd < 0) {
+                        random_fd = open("/dev/urandom", O_WRONLY|O_CLOEXEC|O_NOCTTY, 0600);
+                        if (random_fd < 0) {
+                                r = log_error_errno(errno, "Failed to open /dev/urandom: %m");
+                                goto finish;
+                        }
+                }
+
+                k = loop_read(seed_fd, buf, buf_size, false);
+                if (k < 0)
+                        r = log_error_errno(k, "Failed to read seed from " RANDOM_SEED ": %m");
+                else if (k == 0) {
+                        r = 0;
+                        log_debug("Seed file " RANDOM_SEED " not yet initialized, proceeding.");
+                } else {
+                        (void) lseek(seed_fd, 0, SEEK_SET);
+
+                        r = loop_write(random_fd, buf, (size_t) k, false);
+                        if (r < 0)
+                                log_error_errno(r, "Failed to write seed to /dev/urandom: %m");
+                }
+
+        } else if (streq(argv[1], "save")) {
+
+                seed_fd = open(RANDOM_SEED, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600);
+                if (seed_fd < 0) {
+                        r = log_error_errno(errno, "Failed to open " RANDOM_SEED ": %m");
+                        goto finish;
+                }
+
+                random_fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+                if (random_fd < 0) {
+                        r = log_error_errno(errno, "Failed to open /dev/urandom: %m");
+                        goto finish;
+                }
+
+        } else {
+                log_error("Unknown verb '%s'.", argv[1]);
+                r = -EINVAL;
+                goto finish;
+        }
+
+        if (refresh_seed_file) {
+
+                /* This is just a safety measure. Given that we are root and
+                 * most likely created the file ourselves the mode and owner
+                 * should be correct anyway. */
+                (void) fchmod(seed_fd, 0600);
+                (void) fchown(seed_fd, 0, 0);
+
+                k = loop_read(random_fd, buf, buf_size, false);
+                if (k < 0) {
+                        r = log_error_errno(k, "Failed to read new seed from /dev/urandom: %m");
+                        goto finish;
+                }
+                if (k == 0) {
+                        log_error("Got EOF while reading from /dev/urandom.");
+                        r = -EIO;
+                        goto finish;
+                }
+
+                r = loop_write(seed_fd, buf, (size_t) k, false);
+                if (r < 0)
+                        log_error_errno(r, "Failed to write new random seed file: %m");
+        }
+
+finish:
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}
diff --git a/src/grp-initprogs/systemd-random-seed/systemd-random-seed.service.in b/src/grp-initprogs/systemd-random-seed/systemd-random-seed.service.in
new file mode 100644
index 0000000000..115233268d
--- /dev/null
+++ b/src/grp-initprogs/systemd-random-seed/systemd-random-seed.service.in
@@ -0,0 +1,22 @@
+#  This file is part of systemd.
+#
+#  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.
+
+[Unit]
+Description=Load/Save Random Seed
+Documentation=man:systemd-random-seed.service(8) man:random(4)
+DefaultDependencies=no
+RequiresMountsFor=@RANDOM_SEED@
+Conflicts=shutdown.target
+After=systemd-remount-fs.service
+Before=sysinit.target shutdown.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=@rootlibexecdir@/systemd-random-seed load
+ExecStop=@rootlibexecdir@/systemd-random-seed save
+TimeoutSec=30s