Subject: Enhance luksOpen to make use of key_size parameter
In case you want to read your key from a block device (or large file) the
normal behavior is to read the whole thing. However if your key is stored at
the beginning of that file this patch allows you to specify the -s parameter
with luksOpen and just read n bits from that file.
Example:
cryptsetup luksOpen /dev/sda1 sda1 -d /dev/sdb -s 256
Reads only the first 256 bits from /dev/sdb
Not supplying -s option for luksOpen results, as before, in an exhaustive read.
Signed-off-by: Stefan Assmann <sassmann@xxxxxxx>
---
lib/setup.c | 2 +-
src/cryptsetup.c | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
--- a/src/cryptsetup.c
+++ b/src/cryptsetup.c
@@ -276,6 +276,7 @@ static int action_luksOpen(int arg)
.name = action_argv[1],
.device = action_argv[0],
.key_file = opt_key_file,
+ .key_size = (opt_key_size != 0 ? opt_key_size : 0) / 8,
.timeout = opt_timeout,
.tries = opt_tries,
.icb = &cmd_icb,
--- a/lib/setup.c
+++ b/lib/setup.c
@@ -474,7 +474,7 @@ static int __crypt_luks_open(int arg, st
start:
mk=NULL;
- if(get_key("Enter LUKS passphrase: ",&password,&passwordLen, 0, options->key_file, options->passphrase_fd, options->timeout, options->flags))
+ if(get_key("Enter LUKS passphrase: ",&password,&passwordLen, options->key_size, options->key_file, options->passphrase_fd, options->timeout, options->flags))
tries--;
else
tries = 0;
Stefan
--
Stefan Assmann | SUSE LINUX Products GmbH
Software Engineer | Maxfeldstr. 5, D-90409 Nuernberg
Mail: sassmann@xxxxxxx | GF: Markus Rex, HRB 16746 (AG Nuernberg)
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