From: Nir Soffer <nsoffer@redhat.com>
To: Maxim Levitsky <mlevitsk@redhat.com>
Cc: "Kevin Wolf" <kwolf@redhat.com>, "Fam Zheng" <fam@euphon.net>,
"Daniel P. Berrangé" <berrange@redhat.com>,
qemu-block@nongnu.org, "QEMU Developers" <qemu-devel@nongnu.org>,
"Markus Armbruster" <armbru@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Max Reitz" <mreitz@redhat.com>
Subject: Re: [Qemu-devel] [Qemu-block] [PATCH 05/13] qcrypto-luks: clear the masterkey and password before freeing them always
Date: Thu, 22 Aug 2019 02:01:09 +0300 [thread overview]
Message-ID: <CAMRbyyvaOPSD0jxxFzkpnjEWyeNpbbU3r+2U+RKE=4x_1RteOw@mail.gmail.com> (raw)
In-Reply-To: <20190814202219.1870-6-mlevitsk@redhat.com>
On Wed, Aug 14, 2019, 23:23 Maxim Levitsky <mlevitsk@redhat.com> wrote:
> While there are other places where these are still stored in memory,
> this is still one less key material area that can be sniffed with
> various side channel attacks
>
>
>
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
> crypto/block-luks.c | 52 ++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 44 insertions(+), 8 deletions(-)
>
> diff --git a/crypto/block-luks.c b/crypto/block-luks.c
> index e1a4df94b7..336e633df4 100644
> --- a/crypto/block-luks.c
> +++ b/crypto/block-luks.c
> @@ -1023,8 +1023,18 @@ qcrypto_block_luks_load_key(QCryptoBlock *block,
> cleanup:
> qcrypto_ivgen_free(ivgen);
> qcrypto_cipher_free(cipher);
> - g_free(splitkey);
> - g_free(possiblekey);
> +
> + if (splitkey) {
> + memset(splitkey, 0, splitkeylen);
>
I think we need memset_s() or similar replacement, see
https://www.cryptologie.net/article/419/zeroing-memory-compiler-optimizations-and-memset_s/
+ g_free(splitkey);
> + }
> +
> + if (possiblekey) {
> + memset(possiblekey, 0, masterkeylen(luks));
> + g_free(possiblekey);
> +
> + }
> +
> return ret;
> }
>
> @@ -1161,16 +1171,34 @@ qcrypto_block_luks_open(QCryptoBlock *block,
> block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
> block->payload_offset = luks->header.payload_offset *
> block->sector_size;
>
> - g_free(masterkey);
> - g_free(password);
> + if (masterkey) {
> + memset(masterkey, 0, masterkeylen(luks));
> + g_free(masterkey);
> + }
> +
> + if (password) {
> + memset(password, 0, strlen(password));
> + g_free(password);
> + }
> +
> return 0;
>
> fail:
> - g_free(masterkey);
> +
> + if (masterkey) {
> + memset(masterkey, 0, masterkeylen(luks));
> + g_free(masterkey);
> + }
> +
> + if (password) {
> + memset(password, 0, strlen(password));
> + g_free(password);
> + }
> +
> qcrypto_block_free_cipher(block);
> qcrypto_ivgen_free(block->ivgen);
> +
> g_free(luks);
> - g_free(password);
> return ret;
> }
>
> @@ -1459,7 +1487,10 @@ qcrypto_block_luks_create(QCryptoBlock *block,
>
> memset(masterkey, 0, luks->header.key_bytes);
> g_free(masterkey);
> +
> + memset(password, 0, strlen(password));
> g_free(password);
> +
> g_free(cipher_mode_spec);
>
> return 0;
> @@ -1467,9 +1498,14 @@ qcrypto_block_luks_create(QCryptoBlock *block,
> error:
> if (masterkey) {
> memset(masterkey, 0, luks->header.key_bytes);
> + g_free(masterkey);
> }
> - g_free(masterkey);
> - g_free(password);
> +
> + if (password) {
> + memset(password, 0, strlen(password));
> + g_free(password);
> + }
> +
> g_free(cipher_mode_spec);
>
> qcrypto_block_free_cipher(block);
> --
> 2.17.2
>
>
>
next prev parent reply other threads:[~2019-08-21 23:02 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-14 20:22 [Qemu-devel] [PATCH 00/13] RFC: luks/encrypted qcow2 key management Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 01/13] block-crypto: misc refactoring Maxim Levitsky
2019-08-20 16:38 ` Max Reitz
2019-08-22 0:05 ` Maxim Levitsky
2019-08-22 14:34 ` Max Reitz
2019-08-22 15:04 ` Maxim Levitsky
2019-08-21 15:39 ` Daniel P. Berrangé
2019-08-22 0:08 ` Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 02/13] qcrypto-luks: " Maxim Levitsky
2019-08-15 21:40 ` [Qemu-devel] [Qemu-block] " John Snow
2019-08-19 14:21 ` Maxim Levitsky
2019-08-22 10:29 ` Daniel P. Berrangé
2019-08-22 11:04 ` Maxim Levitsky
2019-08-22 11:10 ` Daniel P. Berrangé
2019-08-22 11:13 ` Maxim Levitsky
2019-08-20 17:36 ` [Qemu-devel] " Max Reitz
2019-08-21 23:59 ` Maxim Levitsky
2019-08-22 14:32 ` Max Reitz
2019-08-25 10:46 ` Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 03/13] qcrypto-luks: refactoring: extract load/store/check/parse header functions Maxim Levitsky
2019-08-20 18:01 ` Max Reitz
2019-08-21 22:43 ` Maxim Levitsky
2019-08-22 10:32 ` Daniel P. Berrangé
2019-08-22 10:57 ` Maxim Levitsky
2019-08-22 10:34 ` Daniel P. Berrangé
2019-08-25 14:11 ` Maxim Levitsky
2019-08-22 10:38 ` Daniel P. Berrangé
2019-08-25 14:09 ` Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 04/13] qcrypto-luks: refactoring: simplify the math used for keyslot locations Maxim Levitsky
2019-08-22 10:47 ` Daniel P. Berrangé
2019-08-25 14:30 ` Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 05/13] qcrypto-luks: clear the masterkey and password before freeing them always Maxim Levitsky
2019-08-20 18:12 ` Max Reitz
2019-08-21 22:40 ` Maxim Levitsky
2019-08-22 10:49 ` Daniel P. Berrangé
2019-08-22 10:56 ` Maxim Levitsky
2019-08-25 15:31 ` Maxim Levitsky
2019-08-25 17:15 ` Maxim Levitsky
2019-08-27 8:55 ` Daniel P. Berrangé
2019-08-21 23:01 ` Nir Soffer [this message]
2019-08-21 23:11 ` [Qemu-devel] [Qemu-block] " Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 06/13] qcrypto-luks: implement more rigorous header checking Maxim Levitsky
2019-08-22 11:04 ` Daniel P. Berrangé
2019-08-25 15:40 ` Maxim Levitsky
2019-08-25 16:08 ` Maxim Levitsky
2019-08-26 13:31 ` Eric Blake
2019-08-26 13:39 ` Maxim Levitsky
2019-08-27 8:56 ` Daniel P. Berrangé
2019-08-14 20:22 ` [Qemu-devel] [PATCH 07/13] block: add manage-encryption command (qmp and blockdev) Maxim Levitsky
2019-08-20 18:27 ` Max Reitz
2019-08-21 22:32 ` Maxim Levitsky
2019-08-22 11:14 ` Daniel P. Berrangé
2019-08-21 11:47 ` Markus Armbruster
2019-08-21 22:24 ` Maxim Levitsky
2019-08-22 14:07 ` Markus Armbruster
2019-08-25 16:42 ` Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 08/13] qcrypto: add the plumbing for encryption management Maxim Levitsky
2019-08-22 11:16 ` Daniel P. Berrangé
2019-08-22 11:47 ` Maxim Levitsky
2019-08-22 11:49 ` Daniel P. Berrangé
2019-08-14 20:22 ` [Qemu-devel] [PATCH 09/13] qcrypto-luks: implement the encryption key management Maxim Levitsky
2019-08-22 11:27 ` Daniel P. Berrangé
2019-08-25 17:01 ` Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 10/13] block/crypto: " Maxim Levitsky
2019-08-22 11:29 ` Daniel P. Berrangé
2019-08-22 11:36 ` Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 11/13] block/qcow2: implement the encryption key managment Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 12/13] qemu-img: implement key management Maxim Levitsky
2019-08-20 18:29 ` Max Reitz
2019-08-21 22:33 ` Maxim Levitsky
2019-08-22 11:32 ` Daniel P. Berrangé
2019-08-22 14:42 ` Max Reitz
2019-08-25 17:04 ` Maxim Levitsky
2019-08-14 20:22 ` [Qemu-devel] [PATCH 13/13] iotests : add tests for encryption " Maxim Levitsky
2019-08-14 21:08 ` [Qemu-devel] [PATCH 00/13] RFC: luks/encrypted qcow2 " Eric Blake
2019-08-15 8:49 ` Maxim Levitsky
2019-08-15 9:10 ` Kevin Wolf
2019-08-15 14:18 ` Markus Armbruster
2019-08-15 14:44 ` Maxim Levitsky
2019-08-15 15:00 ` Eric Blake
2019-08-19 12:35 ` Maxim Levitsky
2019-08-21 11:31 ` Markus Armbruster
2019-08-21 13:22 ` Maxim Levitsky
2019-08-20 17:59 ` Max Reitz
2019-08-21 22:00 ` Maxim Levitsky
2019-08-22 11:35 ` Daniel P. Berrangé
2019-08-25 17:10 ` Maxim Levitsky
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAMRbyyvaOPSD0jxxFzkpnjEWyeNpbbU3r+2U+RKE=4x_1RteOw@mail.gmail.com' \
--to=nsoffer@redhat.com \
--cc=armbru@redhat.com \
--cc=berrange@redhat.com \
--cc=fam@euphon.net \
--cc=kwolf@redhat.com \
--cc=mlevitsk@redhat.com \
--cc=mreitz@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).