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 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 index 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
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