crypto: lib/chacha - add array bounds to function prototypes

Add explicit array bounds to the function prototypes for the parameters
that didn't already get handled by the conversion to use chacha_state:

- chacha_block_*():
  Change 'u8 *out' or 'u8 *stream' to u8 out[CHACHA_BLOCK_SIZE].

- hchacha_block_*():
  Change 'u32 *out' or 'u32 *stream' to u32 out[HCHACHA_OUT_WORDS].

- chacha_init():
  Change 'const u32 *key' to 'const u32 key[CHACHA_KEY_WORDS]'.
  Change 'const u8 *iv' to 'const u8 iv[CHACHA_IV_SIZE]'.

No functional changes.  This just makes it clear when fixed-size arrays
are expected.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 8 insertions, 9 deletions

diff --git a/lib/crypto/chacha.c b/lib/crypto/chacha.c
index ae50e441f9fb..ced87dd31a97 100644
--- a/lib/crypto/chacha.c
+++ b/lib/crypto/chacha.c
@@ -67,14 +67,15 @@ static void chacha_permute(struct chacha_state *state, int nrounds)
 /**
  * chacha_block_generic - generate one keystream block and increment block counter
  * @state: input state matrix
- * @stream: output keystream block (64 bytes)
+ * @out: output keystream block
  * @nrounds: number of rounds (20 or 12; 20 is recommended)
  *
  * This is the ChaCha core, a function from 64-byte strings to 64-byte strings.
  * The caller has already converted the endianness of the input.  This function
  * also handles incrementing the block counter in the input matrix.
  */
-void chacha_block_generic(struct chacha_state *state, u8 *stream, int nrounds)
+void chacha_block_generic(struct chacha_state *state,
+			  u8 out[CHACHA_BLOCK_SIZE], int nrounds)
 {
 	struct chacha_state permuted_state = *state;
 	int i;
@@ -83,7 +84,7 @@ void chacha_block_generic(struct chacha_state *state, u8 *stream, int nrounds)
 
 	for (i = 0; i < ARRAY_SIZE(state->x); i++)
 		put_unaligned_le32(permuted_state.x[i] + state->x[i],
-				   &stream[i * sizeof(u32)]);
+				   &out[i * sizeof(u32)]);
 
 	state->x[12]++;
 }
@@ -92,7 +93,7 @@ EXPORT_SYMBOL(chacha_block_generic);
 /**
  * hchacha_block_generic - abbreviated ChaCha core, for XChaCha
  * @state: input state matrix
- * @stream: output (8 32-bit words)
+ * @out: the output words
  * @nrounds: number of rounds (20 or 12; 20 is recommended)
  *
  * HChaCha is the ChaCha equivalent of HSalsa and is an intermediate step
@@ -101,13 +102,13 @@ EXPORT_SYMBOL(chacha_block_generic);
  * of the state.  It should not be used for streaming directly.
  */
 void hchacha_block_generic(const struct chacha_state *state,
-			   u32 *stream, int nrounds)
+			   u32 out[HCHACHA_OUT_WORDS], int nrounds)
 {
 	struct chacha_state permuted_state = *state;
 
 	chacha_permute(&permuted_state, nrounds);
 
-	memcpy(&stream[0], &permuted_state.x[0], 16);
-	memcpy(&stream[4], &permuted_state.x[12], 16);
+	memcpy(&out[0], &permuted_state.x[0], 16);
+	memcpy(&out[4], &permuted_state.x[12], 16);
 }
 EXPORT_SYMBOL(hchacha_block_generic);
diff --git a/lib/crypto/chacha20poly1305.c b/lib/crypto/chacha20poly1305.c
index 2e7bbc1a67ea..fbd3690e2531 100644
--- a/lib/crypto/chacha20poly1305.c
+++ b/lib/crypto/chacha20poly1305.c
@@ -18,8 +18,6 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 
-#define CHACHA_KEY_WORDS	(CHACHA_KEY_SIZE / sizeof(u32))
-
 static void chacha_load_key(u32 *k, const u8 *in)
 {
 	k[0] = get_unaligned_le32(in);