From: Eric Biggers <ebiggers@kernel.org>
To: Mimi Zohar <zohar@linux.ibm.com>
Cc: linux-integrity@vger.kernel.org, linux-fscrypt@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 4/5] ima: support fs-verity file digest based signatures
Date: Thu, 2 Dec 2021 14:07:56 -0800 [thread overview]
Message-ID: <YalDvGjq0inMFKln@sol.localdomain> (raw)
In-Reply-To: <20211202215507.298415-5-zohar@linux.ibm.com>
On Thu, Dec 02, 2021 at 04:55:06PM -0500, Mimi Zohar wrote:
> case IMA_VERITY_DIGSIG:
> - fallthrough;
> + set_bit(IMA_DIGSIG, &iint->atomic_flags);
> +
> + /*
> + * The IMA signature is based on a hash of IMA_VERITY_DIGSIG
> + * and the fs-verity file digest, not directly on the
> + * fs-verity file digest. Both digests should probably be
> + * included in the IMA measurement list, but for now this
> + * digest is only used for verifying the IMA signature.
> + */
> + verity_digest[0] = IMA_VERITY_DIGSIG;
> + memcpy(verity_digest + 1, iint->ima_hash->digest,
> + iint->ima_hash->length);
> +
> + hash.hdr.algo = iint->ima_hash->algo;
> + hash.hdr.length = iint->ima_hash->length;
This is still wrong because the bytes being signed don't include the hash
algorithm. Unless you mean for it to be implicitly always SHA-256? fs-verity
supports SHA-512 too, and it may support other hash algorithms in the future.
- Eric
next prev parent reply other threads:[~2021-12-02 22:08 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-02 21:55 [PATCH v1 0/5] ima: support fs-verity signatures stored as Mimi Zohar
2021-12-02 21:55 ` [PATCH v1 1/5] fs-verity: define a function to return the integrity protected file digest Mimi Zohar
2021-12-02 22:15 ` Eric Biggers
2021-12-02 21:55 ` [PATCH v1 2/5] ima: define a new signature type named IMA_VERITY_DIGSIG Mimi Zohar
2021-12-02 21:55 ` [PATCH v1 3/5] ima: limit including fs-verity's file digest in measurement list Mimi Zohar
2021-12-02 22:22 ` Eric Biggers
2021-12-02 22:55 ` Mimi Zohar
2021-12-02 21:55 ` [PATCH v1 4/5] ima: support fs-verity file digest based signatures Mimi Zohar
2021-12-02 22:07 ` Eric Biggers [this message]
2021-12-02 22:13 ` Mimi Zohar
2021-12-02 22:18 ` Eric Biggers
2021-12-31 15:35 ` Mimi Zohar
2022-01-05 23:37 ` Eric Biggers
2022-01-09 20:45 ` Vitaly Chikunov
2022-01-09 21:07 ` Eric Biggers
2022-01-15 5:31 ` Vitaly Chikunov
2022-01-15 6:21 ` Eric Biggers
2022-01-16 3:31 ` Stefan Berger
2022-01-16 5:24 ` Stefan Berger
2022-01-19 0:49 ` Eric Biggers
2022-01-19 15:41 ` Stefan Berger
2022-01-16 17:01 ` Mimi Zohar
2022-01-19 0:39 ` Eric Biggers
2022-01-20 16:39 ` Mimi Zohar
2022-01-20 21:05 ` Eric Biggers
2021-12-02 21:55 ` [PATCH v1 5/5] fsverity: update the documentation Mimi Zohar
2021-12-02 22:09 ` Eric Biggers
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