+/*
+ * utils_crypt - cipher utilities for cryptsetup
+ *
+ * Copyright (C) 2004-2007, Clemens Fruhwirth <clemens@endorphin.org>
+ * Copyright (C) 2009-2012, Red Hat, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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 <stdlib.h>
#include <stddef.h>
#include <stdio.h>
#include "nls.h"
#include "utils_crypt.h"
+#define log_dbg(x) crypt_log(NULL, CRYPT_LOG_DEBUG, x)
+#define log_err(cd, x) crypt_log(cd, CRYPT_LOG_ERROR, x)
+
struct safe_allocation {
size_t size;
char data[0];
};
-int crypt_parse_name_and_mode(const char *s, char *cipher, char *cipher_mode)
+int crypt_parse_name_and_mode(const char *s, char *cipher, int *key_nums,
+ char *cipher_mode)
{
if (sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]-%" MAX_CIPHER_LEN_STR "s",
cipher, cipher_mode) == 2) {
+ if (!strcmp(cipher_mode, "plain"))
+ strncpy(cipher_mode, "cbc-plain", 10);
+ if (key_nums) {
+ char *tmp = strchr(cipher, ':');
+ *key_nums = tmp ? atoi(++tmp) : 1;
+ if (!*key_nums)
+ return -EINVAL;
+ }
+
+ return 0;
+ }
+
+ /* Short version for "empty" cipher */
+ if (!strcmp(s, "null")) {
+ strncpy(cipher, "cipher_null", MAX_CIPHER_LEN);
+ strncpy(cipher_mode, "ecb", 9);
+ if (key_nums)
+ *key_nums = 0;
return 0;
}
if (sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]", cipher) == 1) {
- strncpy(cipher_mode, "cbc-plain", 9);
+ strncpy(cipher_mode, "cbc-plain", 10);
+ if (key_nums)
+ *key_nums = 1;
return 0;
}
if (!data)
return;
- alloc = data - offsetof(struct safe_allocation, data);
+ alloc = (struct safe_allocation *)
+ ((char *)data - offsetof(struct safe_allocation, data));
memset(data, 0, alloc->size);
void *crypt_safe_realloc(void *data, size_t size)
{
+ struct safe_allocation *alloc;
void *new_data;
new_data = crypt_safe_alloc(size);
if (new_data && data) {
- struct safe_allocation *alloc;
- alloc = data - offsetof(struct safe_allocation, data);
+ alloc = (struct safe_allocation *)
+ ((char *)data - offsetof(struct safe_allocation, data));
if (size > alloc->size)
size = alloc->size;
crypt_safe_free(data);
return new_data;
}
+
+/* Password reading helpers */
+static int untimed_read(int fd, char *pass, size_t maxlen)
+{
+ ssize_t i;
+
+ i = read(fd, pass, maxlen);
+ if (i > 0) {
+ pass[i-1] = '\0';
+ i = 0;
+ } else if (i == 0) { /* EOF */
+ *pass = 0;
+ i = -1;
+ }
+ return i;
+}
+
+static int timed_read(int fd, char *pass, size_t maxlen, long timeout)
+{
+ struct timeval t;
+ fd_set fds;
+ int failed = -1;
+
+ FD_ZERO(&fds);
+ FD_SET(fd, &fds);
+ t.tv_sec = timeout;
+ t.tv_usec = 0;
+
+ if (select(fd+1, &fds, NULL, NULL, &t) > 0)
+ failed = untimed_read(fd, pass, maxlen);
+
+ return failed;
+}
+
+static int interactive_pass(const char *prompt, char *pass, size_t maxlen,
+ long timeout)
+{
+ struct termios orig, tmp;
+ int failed = -1;
+ int infd = STDIN_FILENO, outfd;
+
+ if (maxlen < 1)
+ goto out_err;
+
+ /* Read and write to /dev/tty if available */
+ if ((infd = outfd = open("/dev/tty", O_RDWR)) == -1) {
+ infd = STDIN_FILENO;
+ outfd = STDERR_FILENO;
+ }
+
+ if (tcgetattr(infd, &orig))
+ goto out_err;
+
+ memcpy(&tmp, &orig, sizeof(tmp));
+ tmp.c_lflag &= ~ECHO;
+
+ if (prompt && write(outfd, prompt, strlen(prompt)) < 0)
+ goto out_err;
+
+ tcsetattr(infd, TCSAFLUSH, &tmp);
+ if (timeout)
+ failed = timed_read(infd, pass, maxlen, timeout);
+ else
+ failed = untimed_read(infd, pass, maxlen);
+ tcsetattr(infd, TCSAFLUSH, &orig);
+
+out_err:
+ if (!failed && write(outfd, "\n", 1)) {};
+
+ if (infd != STDIN_FILENO)
+ close(infd);
+ return failed;
+}
+
+static int crypt_get_key_tty(const char *prompt,
+ char **key, size_t *key_size,
+ int timeout, int verify,
+ struct crypt_device *cd)
+{
+ int key_size_max = DEFAULT_PASSPHRASE_SIZE_MAX;
+ int r = -EINVAL;
+ char *pass = NULL, *pass_verify = NULL;
+
+ log_dbg("Interactive passphrase entry requested.");
+
+ pass = crypt_safe_alloc(key_size_max + 1);
+ if (!pass) {
+ log_err(cd, _("Out of memory while reading passphrase.\n"));
+ return -ENOMEM;
+ }
+
+ if (interactive_pass(prompt, pass, key_size_max, timeout)) {
+ log_err(cd, _("Error reading passphrase from terminal.\n"));
+ goto out_err;
+ }
+ pass[key_size_max] = '\0';
+
+ if (verify) {
+ pass_verify = crypt_safe_alloc(key_size_max);
+ if (!pass_verify) {
+ log_err(cd, _("Out of memory while reading passphrase.\n"));
+ r = -ENOMEM;
+ goto out_err;
+ }
+
+ if (interactive_pass(_("Verify passphrase: "),
+ pass_verify, key_size_max, timeout)) {
+ log_err(cd, _("Error reading passphrase from terminal.\n"));
+ goto out_err;
+ }
+
+ if (strncmp(pass, pass_verify, key_size_max)) {
+ log_err(cd, _("Passphrases do not match.\n"));
+ r = -EPERM;
+ goto out_err;
+ }
+ }
+
+ *key = pass;
+ *key_size = strlen(pass);
+ r = 0;
+out_err:
+ crypt_safe_free(pass_verify);
+ if (r)
+ crypt_safe_free(pass);
+ return r;
+}
+
+/*
+ * Note: --key-file=- is interpreted as a read from a binary file (stdin)
+ * key_size_max == 0 means detect maximum according to input type (tty/file)
+ * timeout and verify options only applies to tty input
+ */
+int crypt_get_key(const char *prompt,
+ char **key, size_t *key_size,
+ size_t keyfile_offset, size_t keyfile_size_max,
+ const char *key_file, int timeout, int verify,
+ struct crypt_device *cd)
+{
+ int fd, regular_file, read_stdin, char_read, unlimited_read = 0;
+ int r = -EINVAL;
+ char *pass = NULL, tmp;
+ size_t buflen, i, file_read_size;
+ struct stat st;
+
+ *key = NULL;
+ *key_size = 0;
+
+ /* Passphrase read from stdin? */
+ read_stdin = (!key_file || !strcmp(key_file, "-")) ? 1 : 0;
+
+ if (read_stdin && isatty(STDIN_FILENO)) {
+ if (keyfile_offset) {
+ log_err(cd, _("Cannot use offset with terminal input.\n"));
+ return -EINVAL;
+ }
+ return crypt_get_key_tty(prompt, key, key_size, timeout, verify, cd);
+ }
+
+ if (read_stdin)
+ log_dbg("STDIN descriptor passphrase entry requested.");
+ else
+ log_dbg("File descriptor passphrase entry requested.");
+
+ /* If not requsted otherwise, we limit input to prevent memory exhaustion */
+ if (keyfile_size_max == 0) {
+ keyfile_size_max = DEFAULT_KEYFILE_SIZE_MAXKB * 1024;
+ unlimited_read = 1;
+ }
+
+ fd = read_stdin ? STDIN_FILENO : open(key_file, O_RDONLY);
+ if (fd < 0) {
+ log_err(cd, _("Failed to open key file.\n"));
+ return -EINVAL;
+ }
+
+ /* use 4k for buffer (page divisor but avoid huge pages) */
+ buflen = 4096 - sizeof(struct safe_allocation);
+ regular_file = 0;
+ if(!read_stdin) {
+ if(stat(key_file, &st) < 0) {
+ log_err(cd, _("Failed to stat key file.\n"));
+ goto out_err;
+ }
+ if(S_ISREG(st.st_mode)) {
+ regular_file = 1;
+ file_read_size = (size_t)st.st_size;
+
+ if (keyfile_offset > file_read_size) {
+ log_err(cd, _("Cannot seek to requested keyfile offset.\n"));
+ goto out_err;
+ }
+ file_read_size -= keyfile_offset;
+
+ /* known keyfile size, alloc it in one step */
+ if (file_read_size >= keyfile_size_max)
+ buflen = keyfile_size_max;
+ 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.\n"));
+ goto out_err;
+ }
+
+ /* Discard keyfile_offset bytes on input */
+ for(i = 0; i < keyfile_offset; i++)
+ if (read(fd, &tmp, 1) != 1) {
+ log_err(cd, _("Cannot seek to requested keyfile offset.\n"));
+ goto out_err;
+ }
+
+ for(i = 0; i < keyfile_size_max; i++) {
+ if(i == buflen) {
+ buflen += 4096;
+ pass = crypt_safe_realloc(pass, buflen);
+ if (!pass) {
+ log_err(cd, _("Out of memory while reading passphrase.\n"));
+ r = -ENOMEM;
+ goto out_err;
+ }
+ }
+
+ char_read = read(fd, &pass[i], 1);
+ if (char_read < 0) {
+ log_err(cd, _("Error reading passphrase.\n"));
+ goto out_err;
+ }
+
+ /* Stop on newline only if not requested read from keyfile */
+ if(char_read == 0 || (!key_file && pass[i] == '\n'))
+ break;
+ }
+
+ /* Fail if piped input dies reading nothing */
+ if(!i && !regular_file) {
+ log_dbg("Nothing read on input.");
+ r = -EPIPE;
+ goto out_err;
+ }
+
+ /* Fail if we exceeded internal default (no specified size) */
+ if (unlimited_read && i == keyfile_size_max) {
+ log_err(cd, _("Maximum keyfile size exceeded.\n"));
+ goto out_err;
+ }
+
+ if (!unlimited_read && i != keyfile_size_max) {
+ log_err(cd, _("Cannot read requested amount of data.\n"));
+ goto out_err;
+ }
+
+ *key = pass;
+ *key_size = i;
+ r = 0;
+out_err:
+ if(fd != STDIN_FILENO)
+ close(fd);
+
+ if (r)
+ crypt_safe_free(pass);
+ return r;
+}