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authorTom Gundersen <teg@jklm.no>2012-08-03 12:47:24 +0200
committerLennart Poettering <lennart@poettering.net>2012-08-03 20:49:55 +0200
commit4271d8235f1186ddad54f432eaca10f8e3bd255f (patch)
tree0769a23c4e97f823ba00f4a0aba89e5188b365e6
parentf9a3b83bf4e24ab50c43b7502afbb701782d87a7 (diff)
cryptsetup: add keyfile-size= support
This is useful e.g. if the keyfile is a raw device, where only parts of it should be read. It is typically used whenever the keyfile-offset= option is specified. Tested-by: Erik Westrup <erik.westrup@gmail.com>
-rw-r--r--man/crypttab.xml12
-rw-r--r--src/cryptsetup/cryptsetup.c22
2 files changed, 27 insertions, 7 deletions
diff --git a/man/crypttab.xml b/man/crypttab.xml
index 2fa8e8940f..8711272a87 100644
--- a/man/crypttab.xml
+++ b/man/crypttab.xml
@@ -131,6 +131,18 @@
<varlistentry>
+ <term><varname>keyfile-size=</varname></term>
+
+ <listitem><para>Specifies the maximum number
+ of bytes to read from the keyfile; see
+ <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for possible values and the default
+ value of this option. This option is ignored
+ in plain encryption mode, as the keyfile-size is then given by the key size.</para></listitem>
+ </varlistentry>
+
+
+ <varlistentry>
<term><varname>keyfile-offset=</varname></term>
<listitem><para>Specifies the number
diff --git a/src/cryptsetup/cryptsetup.c b/src/cryptsetup/cryptsetup.c
index cc30e50003..916509ab93 100644
--- a/src/cryptsetup/cryptsetup.c
+++ b/src/cryptsetup/cryptsetup.c
@@ -37,6 +37,7 @@
static const char *opt_type = NULL; /* LUKS1 or PLAIN */
static char *opt_cipher = NULL;
static unsigned opt_key_size = 0;
+static unsigned opt_keyfile_size = 0;
static unsigned opt_keyfile_offset = 0;
static char *opt_hash = NULL;
static unsigned opt_tries = 0;
@@ -80,6 +81,13 @@ static int parse_one_option(const char *option) {
return 0;
}
+ } else if (startswith(option, "keyfile-size=")) {
+
+ if (safe_atou(option+13, &opt_keyfile_size) < 0) {
+ log_error("keyfile-size= parse failure, ignoring.");
+ return 0;
+ }
+
} else if (startswith(option, "keyfile-offset=")) {
if (safe_atou(option+15, &opt_keyfile_offset) < 0) {
@@ -238,7 +246,6 @@ int main(int argc, char *argv[]) {
char **passwords = NULL, *truncated_cipher = NULL;
const char *cipher = NULL, *cipher_mode = NULL, *hash = NULL, *name = NULL;
char *description = NULL, *name_buffer = NULL, *mount_point = NULL;
- unsigned keyfile_size = 0;
if (argc <= 1) {
help();
@@ -437,6 +444,11 @@ int main(int argc, char *argv[]) {
zero(params);
params.hash = hash;
+ /* for CRYPT_PLAIN limit reads
+ * from keyfile to key length, and
+ * ignore keyfile-size */
+ opt_keyfile_size = opt_key_size / 8;
+
/* In contrast to what the name
* crypt_setup() might suggest this
* doesn't actually format anything,
@@ -448,14 +460,10 @@ int main(int argc, char *argv[]) {
cipher_mode,
NULL,
NULL,
- opt_key_size / 8,
+ opt_keyfile_size,
&params);
pass_volume_key = streq(hash, "plain");
-
- /* for CRYPT_PLAIN limit reads
- * from keyfile to key length */
- keyfile_size = opt_key_size / 8;
}
if (k < 0) {
@@ -470,7 +478,7 @@ int main(int argc, char *argv[]) {
argv[3]);
if (key_file)
- k = crypt_activate_by_keyfile_offset(cd, argv[2], CRYPT_ANY_SLOT, key_file, keyfile_size,
+ k = crypt_activate_by_keyfile_offset(cd, argv[2], CRYPT_ANY_SLOT, key_file, opt_keyfile_size,
opt_keyfile_offset, flags);
else {
char **p;