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From:   Dimitri John Ledkov <dimitri.ledkov@canonical.com>
To:     David Howells <dhowells@redhat.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>
Cc:     keyrings@vger.kernel.org, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2] crypto: mscode_parser - remove sha224 authenticode support
Date:   Sat, 21 Oct 2023 01:16:58 +0100
Message-Id: <20231021001658.1602526-1-dimitri.ledkov@canonical.com>
In-Reply-To: <20231010212530.63470-1-dimitri.ledkov@canonical.com>
References: <20231010212530.63470-1-dimitri.ledkov@canonical.com>
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It is possible to stand up your own certificates and sign PE-COFF
binaries using SHA-224. However it never became popular or needed
since it has similar costs as SHA-256. Windows Authenticode
infrastructure never had support for SHA-224, and all secureboot keys
used for linux vmlinuz have always been using at least SHA-256.

Given the point of mscode_parser is to support interoperability with
typical de-facto hashes, remove support for SHA-224 to avoid the
possibility of creating interoperability issues with rhboot/shim,
grub, and non-linux systems trying to sign or verify vmlinux.

SHA-224 itself is not removed from the kernel, as it is truncated
SHA-256. If requested I can write patches to remove SHA-224 support
across all of the drivers.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

Changes since v1:

 * Correct spelling and grammatical mistakes in the commit
   message. This is a request to replace c1d760a471 ("crypto:
   mscode_parser - remove sha224 authenticode support") in cryptodev
   repository with this one.

 crypto/asymmetric_keys/mscode_parser.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c
index 6416bded0e..855cbc46a9 100644
--- a/crypto/asymmetric_keys/mscode_parser.c
+++ b/crypto/asymmetric_keys/mscode_parser.c
@@ -84,9 +84,6 @@ int mscode_note_digest_algo(void *context, size_t hdrlen,
 	case OID_sha512:
 		ctx->digest_algo = "sha512";
 		break;
-	case OID_sha224:
-		ctx->digest_algo = "sha224";
-		break;
 
 	case OID__NR:
 		sprint_oid(value, vlen, buffer, sizeof(buffer));
-- 
2.34.1