[PATCH] KEYS: asymmetric: Fix sign/verify on pkcs1pad without a hash

From: Herbert Xu <herbert@gondor.apana.org.au>
To: Denis Kenzior <denkenz@gmail.com>
Cc: Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
	Marcel Holtmann <marcel@holtmann.org>,
	James Prestwood <prestwoj@gmail.com>,
	David Howells <dhowells@redhat.com>,
	keyrings@vger.kernel.org, Jarkko Sakkinen <jarkko@kernel.org>
Subject: [PATCH] KEYS: asymmetric: Fix sign/verify on pkcs1pad without a hash
Date: Mon, 16 Oct 2023 16:35:36 +0800	[thread overview]
Message-ID: <ZSz12KHsfJmZGjKz@gondor.apana.org.au> (raw)
In-Reply-To: <c917020d-0cb0-4289-a2e3-d9a0fa28151a@gmail.com>

On Thu, Oct 12, 2023 at 10:08:46AM -0500, Denis Kenzior wrote:
>
> Looks like something took out the ability to run sign/verify without a hash
> on asymmetric keys.

Indeed this is what it was.  Please try this patch.  Thanks!

---8<---
The new sign/verify code broke the case of pkcs1pad without a
hash algorithm.  Fix it by setting issig correctly for this case.

Fixes: 63ba4d67594a ("KEYS: asymmetric: Use new crypto interface without scatterlists")
Cc: stable@vger.kernel.org # v6.5
Reported-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index abeecb8329b3..2f9181c4cd59 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -81,14 +81,13 @@ software_key_determine_akcipher(const struct public_key *pkey,
 		 * RSA signatures usually use EMSA-PKCS1-1_5 [RFC3447 sec 8.2].
 		 */
 		if (strcmp(encoding, "pkcs1") == 0) {
+			*sig = op == kernel_pkey_sign ||
+			       op == kernel_pkey_verify;
 			if (!hash_algo) {
-				*sig = false;
 				n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME,
 					     "pkcs1pad(%s)",
 					     pkey->pkey_algo);
 			} else {
-				*sig = op == kernel_pkey_sign ||
-				       op == kernel_pkey_verify;
 				n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME,
 					     "pkcs1pad(%s,%s)",
 					     pkey->pkey_algo, hash_algo);
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
