[PATCH 2/2] dm crypt: support using trusted keys

[PATCH 2/2] dm crypt: support using trusted keys

[Ahmad Fatoum]

Commit 27f5411a718c ("dm crypt: support using encrypted keys") extended
dm-crypt to allow use of "encrypted" keys along with "user" and "logon".

Along the same lines, teach dm-crypt to support "trusted" keys as well.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
Unsure on whether target_type::version is something authors increment or
maintainers fix up. I can respin if needed.

Cc: Jan Lübbe <jlu@pengutronix.de>
Cc: linux-integrity@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
---
 .../admin-guide/device-mapper/dm-crypt.rst    |  2 +-
 drivers/md/Kconfig                            |  1 +
 drivers/md/dm-crypt.c                         | 23 ++++++++++++++++++-
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/device-mapper/dm-crypt.rst b/Documentation/admin-guide/device-mapper/dm-crypt.rst
index 1a6753b76dbb..aa2d04d95df6 100644
--- a/Documentation/admin-guide/device-mapper/dm-crypt.rst
+++ b/Documentation/admin-guide/device-mapper/dm-crypt.rst
@@ -67,7 +67,7 @@ Parameters::
     the value passed in <key_size>.
 
 <key_type>
-    Either 'logon', 'user' or 'encrypted' kernel key type.
+    Either 'logon', 'user', 'encrypted' or 'trusted' kernel key type.
 
 <key_description>
     The kernel keyring key description crypt target should look for
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 9e44c09f6410..f2014385d48b 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -270,6 +270,7 @@ config DM_CRYPT
 	tristate "Crypt target support"
 	depends on BLK_DEV_DM
 	depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
+	depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
 	select CRYPTO
 	select CRYPTO_CBC
 	select CRYPTO_ESSIV
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 7eeb9248eda5..6c7c687e546c 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -37,6 +37,7 @@
 #include <linux/key-type.h>
 #include <keys/user-type.h>
 #include <keys/encrypted-type.h>
+#include <keys/trusted-type.h>
 
 #include <linux/device-mapper.h>
 
@@ -2452,6 +2453,22 @@ static int set_key_encrypted(struct crypt_config *cc, struct key *key)
 	return 0;
 }
 
+static int set_key_trusted(struct crypt_config *cc, struct key *key)
+{
+	const struct trusted_key_payload *tkp;
+
+	tkp = key->payload.data[0];
+	if (!tkp)
+		return -EKEYREVOKED;
+
+	if (cc->key_size != tkp->key_len)
+		return -EINVAL;
+
+	memcpy(cc->key, tkp->key, cc->key_size);
+
+	return 0;
+}
+
 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
 {
 	char *new_key_string, *key_desc;
@@ -2484,6 +2501,10 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string
 		   !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
 		type = &key_type_encrypted;
 		set_key = set_key_encrypted;
+	} else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
+	           !strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
+		type = &key_type_trusted;
+		set_key = set_key_trusted;
 	} else {
 		return -EINVAL;
 	}
@@ -3555,7 +3576,7 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 static struct target_type crypt_target = {
 	.name   = "crypt",
-	.version = {1, 22, 0},
+	.version = {1, 23, 0},
 	.module = THIS_MODULE,
 	.ctr    = crypt_ctr,
 	.dtr    = crypt_dtr,
-- 
2.30.0

Re: [PATCH 2/2] dm crypt: support using trusted keys

[Jarkko Sakkinen]

On Fri, Jan 22, 2021 at 09:43:21AM +0100, Ahmad Fatoum wrote:
> Commit 27f5411a718c ("dm crypt: support using encrypted keys") extended
> dm-crypt to allow use of "encrypted" keys along with "user" and "logon".
> 
> Along the same lines, teach dm-crypt to support "trusted" keys as well.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---

Is it possible to test run this with tmpfs? Would be a good test
target for Sumit's ARM-TEE trusted keys patches.

https://lore.kernel.org/linux-integrity/1604419306-26105-1-git-send-email-sumit.garg@linaro.org/

/Jarkko

> Unsure on whether target_type::version is something authors increment or
> maintainers fix up. I can respin if needed.
> 
> Cc: Jan Lübbe <jlu@pengutronix.de>
> Cc: linux-integrity@vger.kernel.org
> Cc: keyrings@vger.kernel.org
> Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
> ---
>  .../admin-guide/device-mapper/dm-crypt.rst    |  2 +-
>  drivers/md/Kconfig                            |  1 +
>  drivers/md/dm-crypt.c                         | 23 ++++++++++++++++++-
>  3 files changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/admin-guide/device-mapper/dm-crypt.rst b/Documentation/admin-guide/device-mapper/dm-crypt.rst
> index 1a6753b76dbb..aa2d04d95df6 100644
> --- a/Documentation/admin-guide/device-mapper/dm-crypt.rst
> +++ b/Documentation/admin-guide/device-mapper/dm-crypt.rst
> @@ -67,7 +67,7 @@ Parameters::
>      the value passed in <key_size>.
>  
>  <key_type>
> -    Either 'logon', 'user' or 'encrypted' kernel key type.
> +    Either 'logon', 'user', 'encrypted' or 'trusted' kernel key type.
>  
>  <key_description>
>      The kernel keyring key description crypt target should look for
> diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
> index 9e44c09f6410..f2014385d48b 100644
> --- a/drivers/md/Kconfig
> +++ b/drivers/md/Kconfig
> @@ -270,6 +270,7 @@ config DM_CRYPT
>  	tristate "Crypt target support"
>  	depends on BLK_DEV_DM
>  	depends on (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
> +	depends on (TRUSTED_KEYS || TRUSTED_KEYS=n)
>  	select CRYPTO
>  	select CRYPTO_CBC
>  	select CRYPTO_ESSIV
> diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
> index 7eeb9248eda5..6c7c687e546c 100644
> --- a/drivers/md/dm-crypt.c
> +++ b/drivers/md/dm-crypt.c
> @@ -37,6 +37,7 @@
>  #include <linux/key-type.h>
>  #include <keys/user-type.h>
>  #include <keys/encrypted-type.h>
> +#include <keys/trusted-type.h>
>  
>  #include <linux/device-mapper.h>
>  
> @@ -2452,6 +2453,22 @@ static int set_key_encrypted(struct crypt_config *cc, struct key *key)
>  	return 0;
>  }
>  
> +static int set_key_trusted(struct crypt_config *cc, struct key *key)
> +{
> +	const struct trusted_key_payload *tkp;
> +
> +	tkp = key->payload.data[0];
> +	if (!tkp)
> +		return -EKEYREVOKED;
> +
> +	if (cc->key_size != tkp->key_len)
> +		return -EINVAL;
> +
> +	memcpy(cc->key, tkp->key, cc->key_size);
> +
> +	return 0;
> +}
> +
>  static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
>  {
>  	char *new_key_string, *key_desc;
> @@ -2484,6 +2501,10 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string
>  		   !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
>  		type = &key_type_encrypted;
>  		set_key = set_key_encrypted;
> +	} else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
> +	           !strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
> +		type = &key_type_trusted;
> +		set_key = set_key_trusted;
>  	} else {
>  		return -EINVAL;
>  	}
> @@ -3555,7 +3576,7 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
>  
>  static struct target_type crypt_target = {
>  	.name   = "crypt",
> -	.version = {1, 22, 0},
> +	.version = {1, 23, 0},
>  	.module = THIS_MODULE,
>  	.ctr    = crypt_ctr,
>  	.dtr    = crypt_dtr,
> -- 
> 2.30.0
> 
> 

Re: [PATCH 2/2] dm crypt: support using trusted keys

[Jarkko Sakkinen]

On Fri, Jan 22, 2021 at 08:05:51PM +0200, Jarkko Sakkinen wrote:
> On Fri, Jan 22, 2021 at 09:43:21AM +0100, Ahmad Fatoum wrote:
> > Commit 27f5411a718c ("dm crypt: support using encrypted keys") extended
> > dm-crypt to allow use of "encrypted" keys along with "user" and "logon".
> > 
> > Along the same lines, teach dm-crypt to support "trusted" keys as well.
> > 
> > Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> > ---
> 
> Is it possible to test run this with tmpfs? Would be a good test
> target for Sumit's ARM-TEE trusted keys patches.
> 
> https://lore.kernel.org/linux-integrity/1604419306-26105-1-git-send-email-sumit.garg@linaro.org/

Also, I would hold merging *this* patch up until we are able to
test TEE trusted keys with TEE trusted keys.

/Jarkko

Re: [PATCH 2/2] dm crypt: support using trusted keys

[Ahmad Fatoum]

Hello Jarkko,

On 22.01.21 19:18, Jarkko Sakkinen wrote:
> On Fri, Jan 22, 2021 at 08:05:51PM +0200, Jarkko Sakkinen wrote:
>> On Fri, Jan 22, 2021 at 09:43:21AM +0100, Ahmad Fatoum wrote:
>>> Commit 27f5411a718c ("dm crypt: support using encrypted keys") extended
>>> dm-crypt to allow use of "encrypted" keys along with "user" and "logon".
>>>
>>> Along the same lines, teach dm-crypt to support "trusted" keys as well.
>>>
>>> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
>>> ---
>>
>> Is it possible to test run this with tmpfs? Would be a good test
>> target for Sumit's ARM-TEE trusted keys patches.

I tested these on top of Sumit's patches with TPM and a CAAM blobifier
backend, I am preparing. The system I am developing these patches against
doesn't have a TEE.  Steps to test these changes:

#!/bin/sh

DEV=/dev/loop0
ALGO=aes-cbc-essiv:sha256
KEYNAME=kmk
BLOCKS=20

fallocate -l $((BLOCKS*512)) /tmp/loop0.img
losetup -P $DEV /tmp/loop0.img
mount -o remount,rw /
KEY="$(keyctl add trusted $KEYNAME 'new 32' @s)"
keyctl pipe $KEY >$HOME/kmk.blob

TABLE="0 $BLOCKS crypt $ALGO :32:trusted:$KEYNAME 0 $DEV 0 1 allow_discards"
echo $TABLE | dmsetup create mydev
echo $TABLE | dmsetup load mydev
dd if=/dev/zero of=/dev/mapper/mydev
echo "It works!" 1<> /dev/mapper/mydev
cryptsetup close mydev

reboot

DEV=/dev/loop0
ALGO=aes-cbc-essiv:sha256
KEYNAME=kmk
BLOCKS=20

losetup -P $DEV $HOME/loop0.img
keyctl add trusted $KEYNAME "load $(cat $HOME/kmk.blob)" @s
TABLE="0 $BLOCKS crypt $ALGO :32:trusted:$KEYNAME 0 $DEV 0 1 allow_discards"
echo $TABLE | dmsetup create mydev
echo $TABLE | dmsetup load mydev

# should print that It works!
hexdump -C /dev/mapper/mydev

>> https://lore.kernel.org/linux-integrity/1604419306-26105-1-git-send-email-sumit.garg@linaro.org/
> 
> Also, I would hold merging *this* patch up until we are able to
> test TEE trusted keys with TEE trusted keys.

Which blocks which? I tested this with TPM-Trusted keys, so it's usable
as is. For convenient usage, it would be nice to have cryptsetup
support for trusted and encrypted keys. I intended to look at this next week.

Cheers,
Ahmad

> 
> /Jarkko
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH 2/2] dm crypt: support using trusted keys

[Ahmad Fatoum]

On 22.01.21 20:04, Ahmad Fatoum wrote:
> On 22.01.21 19:18, Jarkko Sakkinen wrote:
>> On Fri, Jan 22, 2021 at 08:05:51PM +0200, Jarkko Sakkinen wrote:
>>> On Fri, Jan 22, 2021 at 09:43:21AM +0100, Ahmad Fatoum wrote:
>>>> Commit 27f5411a718c ("dm crypt: support using encrypted keys") extended
>>>> dm-crypt to allow use of "encrypted" keys along with "user" and "logon".
>>>>
>>>> Along the same lines, teach dm-crypt to support "trusted" keys as well.

Gentle ping.
Is there anything further you require from me regarding these two patches?

>>>>
>>>> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
>>>> ---
>>>
>>> Is it possible to test run this with tmpfs? Would be a good test
>>> target for Sumit's ARM-TEE trusted keys patches.
> 
> I tested these on top of Sumit's patches with TPM and a CAAM blobifier
> backend, I am preparing. The system I am developing these patches against
> doesn't have a TEE.  Steps to test these changes:
> 
> #!/bin/sh
> 
> DEV=/dev/loop0
> ALGO=aes-cbc-essiv:sha256
> KEYNAME=kmk
> BLOCKS=20
> 
> fallocate -l $((BLOCKS*512)) /tmp/loop0.img
> losetup -P $DEV /tmp/loop0.img
> mount -o remount,rw /
> KEY="$(keyctl add trusted $KEYNAME 'new 32' @s)"
> keyctl pipe $KEY >$HOME/kmk.blob
> 
> TABLE="0 $BLOCKS crypt $ALGO :32:trusted:$KEYNAME 0 $DEV 0 1 allow_discards"
> echo $TABLE | dmsetup create mydev
> echo $TABLE | dmsetup load mydev
> dd if=/dev/zero of=/dev/mapper/mydev
> echo "It works!" 1<> /dev/mapper/mydev
> cryptsetup close mydev
> 
> reboot
> 
> DEV=/dev/loop0
> ALGO=aes-cbc-essiv:sha256
> KEYNAME=kmk
> BLOCKS=20
> 
> losetup -P $DEV $HOME/loop0.img
> keyctl add trusted $KEYNAME "load $(cat $HOME/kmk.blob)" @s
> TABLE="0 $BLOCKS crypt $ALGO :32:trusted:$KEYNAME 0 $DEV 0 1 allow_discards"
> echo $TABLE | dmsetup create mydev
> echo $TABLE | dmsetup load mydev
> 
> # should print that It works!
> hexdump -C /dev/mapper/mydev
> 
>>> https://lore.kernel.org/linux-integrity/1604419306-26105-1-git-send-email-sumit.garg@linaro.org/
>>
>> Also, I would hold merging *this* patch up until we are able to
>> test TEE trusted keys with TEE trusted keys.
> 
> Which blocks which? I tested this with TPM-Trusted keys, so it's usable
> as is. For convenient usage, it would be nice to have cryptsetup
> support for trusted and encrypted keys. I intended to look at this next week.
> 
> Cheers,
> Ahmad
> 
>>
>> /Jarkko
>>
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |