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: 1c08a10436 ("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>

arch/arm/crypto/poly1305-glue.c

@@ -29,7 +29,7 @@ void __weak poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit)
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
 
-void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
+void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
 {
 	poly1305_init_arm(&dctx->h, key);
 	dctx->s[0] = get_unaligned_le32(key + 16);

arch/arm64/crypto/poly1305-glue.c

@@ -25,7 +25,7 @@ asmlinkage void poly1305_emit(void *state, u8 *digest, const u32 *nonce);
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
 
-void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
+void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
 {
 	poly1305_init_arm64(&dctx->h, key);
 	dctx->s[0] = get_unaligned_le32(key + 16);

arch/mips/crypto/poly1305-glue.c

@@ -17,7 +17,7 @@ asmlinkage void poly1305_init_mips(void *state, const u8 *key);
 asmlinkage void poly1305_blocks_mips(void *state, const u8 *src, u32 len, u32 hibit);
 asmlinkage void poly1305_emit_mips(void *state, u8 *digest, const u32 *nonce);
 
-void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
+void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
 {
 	poly1305_init_mips(&dctx->h, key);
 	dctx->s[0] = get_unaligned_le32(key + 16);

arch/x86/crypto/poly1305_glue.c

@@ -16,7 +16,7 @@
 #include <asm/simd.h>
 
 asmlinkage void poly1305_init_x86_64(void *ctx,
-				     const u8 key[POLY1305_KEY_SIZE]);
+				     const u8 key[POLY1305_BLOCK_SIZE]);
 asmlinkage void poly1305_blocks_x86_64(void *ctx, const u8 *inp,
 				       const size_t len, const u32 padbit);
 asmlinkage void poly1305_emit_x86_64(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
@@ -81,7 +81,7 @@ static void convert_to_base2_64(void *ctx)
 	state->is_base2_26 = 0;
 }
 
-static void poly1305_simd_init(void *ctx, const u8 key[POLY1305_KEY_SIZE])
+static void poly1305_simd_init(void *ctx, const u8 key[POLY1305_BLOCK_SIZE])
 {
 	poly1305_init_x86_64(ctx, key);
 }
@@ -129,7 +129,7 @@ static void poly1305_simd_emit(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
 		poly1305_emit_avx(ctx, mac, nonce);
 }
 
-void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
+void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
 {
 	poly1305_simd_init(&dctx->h, key);
 	dctx->s[0] = get_unaligned_le32(&key[16]);

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){};

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_arch(struct poly1305_desc_ctx *desc,
-void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key);
+			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)
 {

lib/crypto/poly1305-donna32.c

@@ -10,7 +10,8 @@
 #include <asm/unaligned.h>
 #include <crypto/internal/poly1305.h>
 
-void poly1305_core_setkey(struct poly1305_core_key *key, const u8 raw_key[16])
+void poly1305_core_setkey(struct poly1305_core_key *key,
+			  const u8 raw_key[POLY1305_BLOCK_SIZE])
 {
 	/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
 	key->key.r[0] = (get_unaligned_le32(&raw_key[0])) & 0x3ffffff;

lib/crypto/poly1305-donna64.c

@@ -12,7 +12,8 @@
 
 typedef __uint128_t u128;
 
-void poly1305_core_setkey(struct poly1305_core_key *key, const u8 raw_key[16])
+void poly1305_core_setkey(struct poly1305_core_key *key,
+			  const u8 raw_key[POLY1305_BLOCK_SIZE])
 {
 	u64 t0, t1;
 

lib/crypto/poly1305.c

@@ -12,7 +12,8 @@
 #include <linux/module.h>
 #include <asm/unaligned.h>
 
-void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key)
+void poly1305_init_generic(struct poly1305_desc_ctx *desc,
+			   const u8 key[POLY1305_KEY_SIZE])
 {
 	poly1305_core_setkey(&desc->core_r, key);
 	desc->s[0] = get_unaligned_le32(key + 16);