[PATCH v6 08/17] crypto/sha3: Add SHAKE128/256 support

[David Howells <dhowells@redhat.com>]

SHAKE128/256 'digest' algos need to be available for the ML-DSA pre-digest,
which is a selectable algorithm and need to be available through the same
API as, say, SHA3-512 and SHA512 both.  Resqueezability (probably) isn't
required for this and they'll produce the default number of bytes as the
digest size.

Also, increase MAX_ALGAPI_BLOCKSIZE to accommodate SHAKE128.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric Biggers <ebiggers@kernel.org>
cc: Jason A. Donenfeld <Jason@zx2c4.com>
cc: Ard Biesheuvel <ardb@kernel.org>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: Stephan Mueller <smueller@chronox.de>
cc: linux-crypto@vger.kernel.org
---
 crypto/sha3_generic.c   | 26 ++++++++++++++++++++++++++
 include/crypto/algapi.h |  2 +-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/crypto/sha3_generic.c b/crypto/sha3_generic.c
index 7b16e4c27fc8..3e5a23022596 100644
--- a/crypto/sha3_generic.c
+++ b/crypto/sha3_generic.c
@@ -95,6 +95,28 @@ static struct shash_alg algs[] = { {
 	.base.cra_flags		= 0,
 	.base.cra_blocksize	= SHA3_512_BLOCK_SIZE,
 	.base.cra_module	= THIS_MODULE,
+}, {
+	.digestsize		= SHAKE128_DEFAULT_SIZE,
+	.init			= crypto_sha3_init,
+	.update			= crypto_sha3_update,
+	.finup			= crypto_sha3_finup,
+	.descsize		= sizeof(struct sha3_ctx),
+	.base.cra_name		= "shake128",
+	.base.cra_driver_name	= "shake128-generic",
+	.base.cra_flags		= 0,
+	.base.cra_blocksize	= SHAKE128_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
+}, {
+	.digestsize		= SHAKE256_DEFAULT_SIZE,
+	.init			= crypto_sha3_init,
+	.update			= crypto_sha3_update,
+	.finup			= crypto_sha3_finup,
+	.descsize		= sizeof(struct sha3_ctx),
+	.base.cra_name		= "shake256",
+	.base.cra_driver_name	= "shake256-generic",
+	.base.cra_flags		= 0,
+	.base.cra_blocksize	= SHAKE256_BLOCK_SIZE,
+	.base.cra_module	= THIS_MODULE,
 } };
 
 static int __init sha3_generic_mod_init(void)
@@ -121,3 +143,7 @@ MODULE_ALIAS_CRYPTO("sha3-384");
 MODULE_ALIAS_CRYPTO("sha3-384-generic");
 MODULE_ALIAS_CRYPTO("sha3-512");
 MODULE_ALIAS_CRYPTO("sha3-512-generic");
+MODULE_ALIAS_CRYPTO("shake128");
+MODULE_ALIAS_CRYPTO("shake128-generic");
+MODULE_ALIAS_CRYPTO("shake256");
+MODULE_ALIAS_CRYPTO("shake256-generic");
diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index fc4574940636..6209762736c4 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -20,7 +20,7 @@
  * static buffers that are big enough for any combination of
  * algs and architectures. Ciphers have a lower maximum size.
  */
-#define MAX_ALGAPI_BLOCKSIZE		160
+#define MAX_ALGAPI_BLOCKSIZE		168
 #define MAX_ALGAPI_ALIGNMASK		127
 #define MAX_CIPHER_BLOCKSIZE		16
 #define MAX_CIPHER_ALIGNMASK		15