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Diffstat (limited to 'lib/utils.c')
-rw-r--r-- | lib/utils.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/lib/utils.c b/lib/utils.c new file mode 100644 index 0000000..63c9189 --- /dev/null +++ b/lib/utils.c @@ -0,0 +1,325 @@ +/* + * 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) 2009-2019 Red Hat, Inc. All rights reserved. + * Copyright (C) 2009-2019 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 <fcntl.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; +} + +/* MEMLOCK */ +#define DEFAULT_PROCESS_PRIORITY -18 + +static int _priority; +static int _memlock_count = 0; + +// return 1 if memory is locked +int crypt_memlock_inc(struct crypt_device *ctx) +{ + if (!_memlock_count++) { + log_dbg(ctx, "Locking memory."); + if (mlockall(MCL_CURRENT | MCL_FUTURE) == -1) { + log_dbg(ctx, "Cannot lock memory with mlockall."); + _memlock_count--; + return 0; + } + errno = 0; + if (((_priority = getpriority(PRIO_PROCESS, 0)) == -1) && errno) + log_err(ctx, _("Cannot get process priority.")); + else + if (setpriority(PRIO_PROCESS, 0, DEFAULT_PROCESS_PRIORITY)) + log_dbg(ctx, "setpriority %d failed: %s", + DEFAULT_PROCESS_PRIORITY, strerror(errno)); + } + return _memlock_count ? 1 : 0; +} + +int crypt_memlock_dec(struct crypt_device *ctx) +{ + if (_memlock_count && (!--_memlock_count)) { + log_dbg(ctx, "Unlocking memory."); + if (munlockall() == -1) + log_err(ctx, _("Cannot unlock memory.")); + if (setpriority(PRIO_PROCESS, 0, _priority)) + log_dbg(ctx, "setpriority %d failed: %s", _priority, strerror(errno)); + } + return _memlock_count ? 1 : 0; +} + +/* 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; + off64_t r; + + r = lseek64(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_memzero(tmp, sizeof(tmp)); + /* read error */ + return -1; + } + + if (bytes_r == 0) + /* EOF */ + break; + + bytes -= bytes_r; + } + + crypt_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.")); + r = -EINVAL; + goto out_err; + } + + /* 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 - 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_err; + } + 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_err; + } + 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_err; + } + + /* 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_err; + } + + 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_err; + } + } + + 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_err; + } + + 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_err; + } + + /* Fail if we exceeded internal default (no specified size) */ + if (unlimited_read && i == key_size) { + log_err(cd, _("Maximum keyfile size exceeded.")); + goto out_err; + } + + if (!unlimited_read && i != key_size) { + log_err(cd, _("Cannot read requested amount of data.")); + goto out_err; + } + + *key = pass; + *key_size_read = i; + r = 0; +out_err: + 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 = version(maj, min, patch, rel); + + return r; +} |