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-rw-r--r--lib/utils.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/lib/utils.c b/lib/utils.c
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+/*
+ * utils - miscellaneous device utilities for cryptsetup
+ *
+ * Copyright (C) 2004 Jana Saout <jana@saout.de>
+ * Copyright (C) 2004-2007 Clemens Fruhwirth <clemens@endorphin.org>
+ * Copyright (C) 2009-2023 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2009-2023 Milan Broz
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/utsname.h>
+
+#include "internal.h"
+
+size_t crypt_getpagesize(void)
+{
+ long r = sysconf(_SC_PAGESIZE);
+ return r <= 0 ? DEFAULT_MEM_ALIGNMENT : (size_t)r;
+}
+
+unsigned crypt_cpusonline(void)
+{
+ long r = sysconf(_SC_NPROCESSORS_ONLN);
+ return r < 0 ? 1 : r;
+}
+
+uint64_t crypt_getphysmemory_kb(void)
+{
+ long pagesize, phys_pages;
+ uint64_t phys_memory_kb;
+
+ pagesize = sysconf(_SC_PAGESIZE);
+ phys_pages = sysconf(_SC_PHYS_PAGES);
+
+ if (pagesize < 0 || phys_pages < 0)
+ return 0;
+
+ phys_memory_kb = pagesize / 1024;
+ phys_memory_kb *= phys_pages;
+
+ return phys_memory_kb;
+}
+
+void crypt_process_priority(struct crypt_device *cd, int *priority, bool raise)
+{
+ int _priority, new_priority;
+
+ if (raise) {
+ _priority = getpriority(PRIO_PROCESS, 0);
+ if (_priority < 0)
+ _priority = 0;
+ if (priority)
+ *priority = _priority;
+
+ /*
+ * Do not bother checking CAP_SYS_NICE as device activation
+ * requires CAP_SYSADMIN later anyway.
+ */
+ if (getuid() || geteuid())
+ new_priority = 0;
+ else
+ new_priority = -18;
+
+ if (setpriority(PRIO_PROCESS, 0, new_priority))
+ log_dbg(cd, "Cannot raise process priority.");
+ } else {
+ _priority = priority ? *priority : 0;
+ if (setpriority(PRIO_PROCESS, 0, _priority))
+ log_dbg(cd, "Cannot reset process priority.");
+ }
+}
+
+/* Keyfile processing */
+
+/*
+ * A simple call to lseek(3) might not be possible for some inputs (e.g.
+ * reading from a pipe), so this function instead reads of up to BUFSIZ bytes
+ * at a time until the specified number of bytes. It returns -1 on read error
+ * or when it reaches EOF before the requested number of bytes have been
+ * discarded.
+ */
+static int keyfile_seek(int fd, uint64_t bytes)
+{
+ char tmp[BUFSIZ];
+ size_t next_read;
+ ssize_t bytes_r;
+ off_t r;
+
+ r = lseek(fd, bytes, SEEK_CUR);
+ if (r > 0)
+ return 0;
+ if (r < 0 && errno != ESPIPE)
+ return -1;
+
+ while (bytes > 0) {
+ /* figure out how much to read */
+ next_read = bytes > sizeof(tmp) ? sizeof(tmp) : (size_t)bytes;
+
+ bytes_r = read(fd, tmp, next_read);
+ if (bytes_r < 0) {
+ if (errno == EINTR)
+ continue;
+
+ crypt_safe_memzero(tmp, sizeof(tmp));
+ /* read error */
+ return -1;
+ }
+
+ if (bytes_r == 0)
+ /* EOF */
+ break;
+
+ bytes -= bytes_r;
+ }
+
+ crypt_safe_memzero(tmp, sizeof(tmp));
+ return bytes == 0 ? 0 : -1;
+}
+
+int crypt_keyfile_device_read(struct crypt_device *cd, const char *keyfile,
+ char **key, size_t *key_size_read,
+ uint64_t keyfile_offset, size_t key_size,
+ uint32_t flags)
+{
+ int fd, regular_file, char_to_read = 0, char_read = 0, unlimited_read = 0;
+ int r = -EINVAL, newline;
+ char *pass = NULL;
+ size_t buflen, i;
+ uint64_t file_read_size;
+ struct stat st;
+
+ if (!key || !key_size_read)
+ return -EINVAL;
+
+ *key = NULL;
+ *key_size_read = 0;
+
+ fd = keyfile ? open(keyfile, O_RDONLY) : STDIN_FILENO;
+ if (fd < 0) {
+ log_err(cd, _("Failed to open key file."));
+ return -EINVAL;
+ }
+
+ if (isatty(fd)) {
+ log_err(cd, _("Cannot read keyfile from a terminal."));
+ goto out;
+ }
+
+ /* If not requested otherwise, we limit input to prevent memory exhaustion */
+ if (key_size == 0) {
+ key_size = DEFAULT_KEYFILE_SIZE_MAXKB * 1024 + 1;
+ unlimited_read = 1;
+ /* use 4k for buffer (page divisor but avoid huge pages) */
+ buflen = 4096 - 16; /* sizeof(struct safe_allocation); */
+ } else
+ buflen = key_size;
+
+ regular_file = 0;
+ if (keyfile) {
+ if (stat(keyfile, &st) < 0) {
+ log_err(cd, _("Failed to stat key file."));
+ goto out;
+ }
+ if (S_ISREG(st.st_mode)) {
+ regular_file = 1;
+ file_read_size = (uint64_t)st.st_size;
+
+ if (keyfile_offset > file_read_size) {
+ log_err(cd, _("Cannot seek to requested keyfile offset."));
+ goto out;
+ }
+ file_read_size -= keyfile_offset;
+
+ /* known keyfile size, alloc it in one step */
+ if (file_read_size >= (uint64_t)key_size)
+ buflen = key_size;
+ else if (file_read_size)
+ buflen = file_read_size;
+ }
+ }
+
+ pass = crypt_safe_alloc(buflen);
+ if (!pass) {
+ log_err(cd, _("Out of memory while reading passphrase."));
+ goto out;
+ }
+
+ /* Discard keyfile_offset bytes on input */
+ if (keyfile_offset && keyfile_seek(fd, keyfile_offset) < 0) {
+ log_err(cd, _("Cannot seek to requested keyfile offset."));
+ goto out;
+ }
+
+ for (i = 0, newline = 0; i < key_size; i += char_read) {
+ if (i == buflen) {
+ buflen += 4096;
+ pass = crypt_safe_realloc(pass, buflen);
+ if (!pass) {
+ log_err(cd, _("Out of memory while reading passphrase."));
+ r = -ENOMEM;
+ goto out;
+ }
+ }
+
+ if (flags & CRYPT_KEYFILE_STOP_EOL) {
+ /* If we should stop on newline, we must read the input
+ * one character at the time. Otherwise we might end up
+ * having read some bytes after the newline, which we
+ * promised not to do.
+ */
+ char_to_read = 1;
+ } else {
+ /* char_to_read = min(key_size - i, buflen - i) */
+ char_to_read = key_size < buflen ?
+ key_size - i : buflen - i;
+ }
+ char_read = read_buffer(fd, &pass[i], char_to_read);
+ if (char_read < 0) {
+ log_err(cd, _("Error reading passphrase."));
+ r = -EPIPE;
+ goto out;
+ }
+
+ if (char_read == 0)
+ break;
+ /* Stop on newline only if not requested read from keyfile */
+ if ((flags & CRYPT_KEYFILE_STOP_EOL) && pass[i] == '\n') {
+ newline = 1;
+ pass[i] = '\0';
+ break;
+ }
+ }
+
+ /* Fail if piped input dies reading nothing */
+ if (!i && !regular_file && !newline) {
+ log_err(cd, _("Nothing to read on input."));
+ r = -EPIPE;
+ goto out;
+ }
+
+ /* Fail if we exceeded internal default (no specified size) */
+ if (unlimited_read && i == key_size) {
+ log_err(cd, _("Maximum keyfile size exceeded."));
+ goto out;
+ }
+
+ if (!unlimited_read && i != key_size) {
+ log_err(cd, _("Cannot read requested amount of data."));
+ goto out;
+ }
+
+ *key = pass;
+ *key_size_read = i;
+ r = 0;
+out:
+ if (fd != STDIN_FILENO)
+ close(fd);
+
+ if (r)
+ crypt_safe_free(pass);
+ return r;
+}
+
+int crypt_keyfile_read(struct crypt_device *cd, const char *keyfile,
+ char **key, size_t *key_size_read,
+ size_t keyfile_offset, size_t keyfile_size_max,
+ uint32_t flags)
+{
+ return crypt_keyfile_device_read(cd, keyfile, key, key_size_read,
+ keyfile_offset, keyfile_size_max, flags);
+}
+
+int kernel_version(uint64_t *kversion)
+{
+ struct utsname uts;
+ uint16_t maj, min, patch, rel;
+ int r = -EINVAL;
+
+ if (uname(&uts) < 0)
+ return r;
+
+ if (sscanf(uts.release, "%" SCNu16 ".%" SCNu16 ".%" SCNu16 "-%" SCNu16,
+ &maj, &min, &patch, &rel) == 4)
+ r = 0;
+ else if (sscanf(uts.release, "%" SCNu16 ".%" SCNu16 ".%" SCNu16,
+ &maj, &min, &patch) == 3) {
+ rel = 0;
+ r = 0;
+ }
+
+ if (!r)
+ *kversion = compact_version(maj, min, patch, rel);
+
+ return r;
+}
+
+bool crypt_string_in(const char *str, char **list, size_t list_size)
+{
+ size_t i;
+
+ for (i = 0; *list && i < list_size; i++, list++)
+ if (!strcmp(str, *list))
+ return true;
+
+ return false;
+}
+
+/* compare two strings (allows NULL values) */
+int crypt_strcmp(const char *a, const char *b)
+{
+ if (!a && !b)
+ return 0;
+ else if (!a || !b)
+ return 1;
+ return strcmp(a, b);
+}
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