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From:   "Herbert Xu" <herbert@gondor.apana.org.au>
Date:   Fri, 19 May 2023 16:28:37 +0800
Subject: [PATCH 3/3] crypto: cmac - Add support for cloning
References: <ZGcyuyjJwZhdYS/G@gondor.apana.org.au>
To:     Dmitry Safonov <dima@arista.com>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        linux-kernel@vger.kernel.org, David Ahern <dsahern@kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Jakub Kicinski <kuba@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Andy Lutomirski <luto@amacapital.net>,
        Ard Biesheuvel <ardb@kernel.org>,
        Bob Gilligan <gilligan@arista.com>,
        Dan Carpenter <error27@gmail.com>,
        David Laight <David.Laight@aculab.com>,
        Dmitry Safonov <0x7f454c46@gmail.com>,
        Eric Biggers <ebiggers@kernel.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Francesco Ruggeri <fruggeri05@gmail.com>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        Ivan Delalande <colona@arista.com>,
        Leonard Crestez <cdleonard@gmail.com>,
        Salam Noureddine <noureddine@arista.com>,
        netdev@vger.kernel.org
Message-Id: <E1pzvTZ-00AnMQ-5M@formenos.hmeau.com>
Precedence: bulk

Allow hmac to be cloned.  The underlying cipher needs to support
cloning by not having a cra_init function (all implementations of
aes that do not require a fallback can be cloned).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

 crypto/cmac.c |   18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/crypto/cmac.c b/crypto/cmac.c
index bcc6f19a4f64..fce6b0f58e88 100644
--- a/crypto/cmac.c
+++ b/crypto/cmac.c
@@ -213,7 +213,22 @@ static int cmac_init_tfm(struct crypto_shash *tfm)
 	ctx->child = cipher;
 
 	return 0;
-};
+}
+
+static int cmac_clone_tfm(struct crypto_shash *tfm, struct crypto_shash *otfm)
+{
+	struct cmac_tfm_ctx *octx = crypto_shash_ctx(otfm);
+	struct cmac_tfm_ctx *ctx = crypto_shash_ctx(tfm);
+	struct crypto_cipher *cipher;
+
+	cipher = crypto_clone_cipher(octx->child);
+	if (IS_ERR(cipher))
+		return PTR_ERR(cipher);
+
+	ctx->child = cipher;
+
+	return 0;
+}
 
 static void cmac_exit_tfm(struct crypto_shash *tfm)
 {
@@ -280,6 +295,7 @@ static int cmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 	inst->alg.final = crypto_cmac_digest_final;
 	inst->alg.setkey = crypto_cmac_digest_setkey;
 	inst->alg.init_tfm = cmac_init_tfm;
+	inst->alg.clone_tfm = cmac_clone_tfm;
 	inst->alg.exit_tfm = cmac_exit_tfm;
 
 	inst->free = shash_free_singlespawn_instance;