crypto: poly1305 - fix poly1305_core_setkey() declaration

gcc-11 points out a mismatch between the declaration and the definition
of poly1305_core_setkey():

lib/crypto/poly1305-donna32.c:13:67: error: argument 2 of type ‘const u8[16]’ {aka ‘const unsigned char[16]’} with mismatched bound [-Werror=array-parameter=]
   13 | void poly1305_core_setkey(struct poly1305_core_key *key, const u8 raw_key[16])
      |                                                          ~~~~~~~~~^~~~~~~~~~~
In file included from lib/crypto/poly1305-donna32.c:11:
include/crypto/internal/poly1305.h:21:68: note: previously declared as ‘const u8 *’ {aka ‘const unsigned char *’}
   21 | void poly1305_core_setkey(struct poly1305_core_key *key, const u8 *raw_key);

This is harmless in principle, as the calling conventions are the same,
but the more specific prototype allows better type checking in the
caller.

Change the declaration to match the actual function definition.
The poly1305_simd_init() is a bit suspicious here, as it previously
had a 32-byte argument type, but looks like it needs to take the
16-byte POLY1305_BLOCK_SIZE array instead.

Fixes: 1c08a104360f ("crypto: poly1305 - add new 32 and 64-bit generic versions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 6 insertions, 3 deletions

diff --git a/include/crypto/internal/poly1305.h b/include/crypto/internal/poly1305.h
index 064e52ca5248..196aa769f296 100644
--- a/include/crypto/internal/poly1305.h
+++ b/include/crypto/internal/poly1305.h
@@ -18,7 +18,8 @@
  * only the ε-almost-∆-universal hash function (not the full MAC) is computed.
  */
 
-void poly1305_core_setkey(struct poly1305_core_key *key, const u8 *raw_key);
+void poly1305_core_setkey(struct poly1305_core_key *key,
+			  const u8 raw_key[POLY1305_BLOCK_SIZE]);
 static inline void poly1305_core_init(struct poly1305_state *state)
 {
 	*state = (struct poly1305_state){};
diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h
index f1f67fc749cf..090692ec3bc7 100644
--- a/include/crypto/poly1305.h
+++ b/include/crypto/poly1305.h
@@ -58,8 +58,10 @@ struct poly1305_desc_ctx {
 	};
 };
 
-void poly1305_init_arch(struct poly1305_desc_ctx *desc, const u8 *key);
-void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key);
+void poly1305_init_arch(struct poly1305_desc_ctx *desc,
+			const u8 key[POLY1305_KEY_SIZE]);
+void poly1305_init_generic(struct poly1305_desc_ctx *desc,
+			   const u8 key[POLY1305_KEY_SIZE]);
 
 static inline void poly1305_init(struct poly1305_desc_ctx *desc, const u8 *key)
 {