[PATCHv12,00/10] nvme: implement secure concatenation

Hi all,

here's my attempt to implement secure concatenation for NVMe-of TCP
as outlined in TP8018.
The original (v5) patchset had been split in two, the first part of
which has already been merged with nvme-6.11, and this is the second part
which actually implements secure concatenation.

Secure concatenation means that a TLS PSK is generated from the key
material negotiated by the DH-HMAC-CHAP protocol, and the TLS PSK
is then used for a subsequent TLS connection.
The difference between the original definition of secure concatenation
and the method outlined in TP8018 is that with TP8018 the connection
is reset after DH-HMAC-CHAP negotiation, and a new connection is setup
with the generated TLS PSK.

To implement that Sagi came up with the idea to directly reset the
admin queue once the DH-CHAP negotiation has completed; that way
it will be transparent to the upper layers and we don't have to
worry about exposing queues which should not be used.

A blktest submission is in
https://github.com/osandov/blktests/pull/147
in case anyone want to run their own tests.

As usual, comments and reviews are welcome.

Patchset can be found at
git.kernel.org:/pub/scm/linux/kernel/git/hare/nvme.git
branch secure-concat.v12

Changes to v11:
- Include reviews from Sagi

Changes to v10:
- Include reviews from Eric Biggers
- Drop test vectors for SHA1
- Add test vectors for SHA384 and SHA512
- Include reviews from Mark O'Donovan

Changes to v9:
- Include reviews from Eric Biggers
- Fixup secure concatenation after reset
- Rebased to nvme-6.12

Changes to v8:
- Include reviews from Eric Biggers
- Make hkdf a proper module
- Add testcases for hkdf

Changes to v7:
- Add patch to display nvme target TLS status in debugfs
- Include reviews from Sagi

Changes to v6:
- Rebase to nvme-6.11

Changes to v5:
- Include reviews from Sagi
- Split patchset in two parts

Changes to v4:
- Rework reset admin queue functionality based on an idea
  from Sagi (thanks!)
  - kbuild robot fixes
  - Fixup dhchap negotiation with non-empty C2 value

Changes to v3:
- Include reviews from Sagi
- Do not start I/O queues after DH-HMAC-CHAP negotiation
- Use bool to indicate TLS has been enabled on a queue
- Add 'tls_keyring' sysfs attribute
- Add 'tls_configured_key' sysfs attribute

Changes to v2:
- Fixup reset after dhchap negotiation
- Disable namespace scanning on I/O queues after
  dhchap negotiation
  - Reworked TLS key handling (again)

Changes to the original submission:
- Sanitize TLS key handling
- Fixup modconfig compilation

Hannes Reinecke (10):
  crypto,fs: Separate out hkdf_extract() and hkdf_expand()
  nvme: add nvme_auth_generate_psk()
  nvme: add nvme_auth_generate_digest()
  nvme: add nvme_auth_derive_tls_psk()
  nvme-keyring: add nvme_tls_psk_refresh()
  nvme: always include <linux/key.h>
  nvme-tcp: request secure channel concatenation
  nvme-fabrics: reset admin connection for secure concatenation
  nvmet-tcp: support secure channel concatenation
  nvmet: add tls_concat and tls_key debugfs entries

 crypto/Kconfig                         |   6 +
 crypto/Makefile                        |   1 +
 crypto/hkdf.c                          | 573 +++++++++++++++++++++++++
 drivers/nvme/common/Kconfig            |   1 +
 drivers/nvme/common/auth.c             | 346 +++++++++++++++
 drivers/nvme/common/keyring.c          |  65 ++-
 drivers/nvme/host/auth.c               | 113 ++++-
 drivers/nvme/host/fabrics.c            |  34 +-
 drivers/nvme/host/fabrics.h            |   3 +
 drivers/nvme/host/nvme.h               |   2 +
 drivers/nvme/host/sysfs.c              |   4 +-
 drivers/nvme/host/tcp.c                |  68 ++-
 drivers/nvme/target/auth.c             |  72 +++-
 drivers/nvme/target/debugfs.c          |  27 ++
 drivers/nvme/target/fabrics-cmd-auth.c |  49 ++-
 drivers/nvme/target/fabrics-cmd.c      |  33 +-
 drivers/nvme/target/nvmet.h            |  38 +-
 drivers/nvme/target/tcp.c              |  24 +-
 fs/crypto/Kconfig                      |   1 +
 fs/crypto/hkdf.c                       |  85 +---
 include/crypto/hkdf.h                  |  20 +
 include/linux/nvme-auth.h              |   7 +
 include/linux/nvme-keyring.h           |  11 +
 include/linux/nvme.h                   |   7 +
 24 files changed, 1480 insertions(+), 110 deletions(-)
 create mode 100644 crypto/hkdf.c
 create mode 100644 include/crypto/hkdf.h

On Mon, Dec 02, 2024 at 03:29:50PM +0100, Hannes Reinecke wrote:
> Separate out the HKDF functions into a separate module to
> to make them available to other callers.
> And add a testsuite to the module with test vectors
> from RFC 5869 (and additional vectors for SHA384 and SHA512)
> to ensure the integrity of the algorithm.
> 
> Signed-off-by: Hannes Reinecke <hare@kernel.org>
> Cc: Eric Biggers <ebiggers@kernel.org>
> Cc: linux-crypto@vger.kernel.org

Acked-by: Eric Biggers <ebiggers@kernel.org>

> +int hkdf_expand(struct crypto_shash *hmac_tfm,
> +		const u8 *info, unsigned int infolen,
> +		u8 *okm, unsigned int okmlen)
> +{
> +	SHASH_DESC_ON_STACK(desc, hmac_tfm);
> +	unsigned int i, hashlen = crypto_shash_digestsize(hmac_tfm);
> +	int err;
> +	const u8 *prev = NULL;
> +	u8 counter = 1;
> +	u8 tmp[HASH_MAX_DIGESTSIZE] = {};

Zero-initializing tmp is not necessary.

- Eric