chacha20: split chacha20_ctx into union

This avoids casts and makes counter increments obvious.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 11 insertions, 11 deletions

diff --git a/src/crypto/zinc/chacha20/chacha20.c b/src/crypto/zinc/chacha20/chacha20.c
index 3415105..3f0392f 100644
--- a/src/crypto/zinc/chacha20/chacha20.c
+++ b/src/crypto/zinc/chacha20/chacha20.c
@@ -25,7 +25,7 @@
 static void __init chacha20_fpu_init(void)
 {
 }
-static inline bool chacha20_arch(struct chacha20_ctx *state, u8 *dst,
+static inline bool chacha20_arch(struct chacha20_ctx *ctx, u8 *dst,
 				 const u8 *src, size_t len,
 				 simd_context_t *simd_context)
 {
@@ -79,45 +79,45 @@ static inline bool hchacha20_arch(u32 derived_key[CHACHA20_KEY_WORDS],
 	DOUBLE_ROUND(x) \
 )
 
-static void chacha20_block_generic(__le32 *stream, u32 *state)
+static void chacha20_block_generic(struct chacha20_ctx *ctx, __le32 *stream)
 {
 	u32 x[CHACHA20_BLOCK_WORDS];
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(x); ++i)
-		x[i] = state[i];
+		x[i] = ctx->state[i];
 
 	TWENTY_ROUNDS(x);
 
 	for (i = 0; i < ARRAY_SIZE(x); ++i)
-		stream[i] = cpu_to_le32(x[i] + state[i]);
+		stream[i] = cpu_to_le32(x[i] + ctx->state[i]);
 
-	++state[12];
+	ctx->counter[0] += 1;
 }
 
-static void chacha20_generic(struct chacha20_ctx *state, u8 *out, const u8 *in,
+static void chacha20_generic(struct chacha20_ctx *ctx, u8 *out, const u8 *in,
 			     u32 len)
 {
 	__le32 buf[CHACHA20_BLOCK_WORDS];
 
 	while (len >= CHACHA20_BLOCK_SIZE) {
-		chacha20_block_generic(buf, (u32 *)state);
+		chacha20_block_generic(ctx, buf);
 		crypto_xor_cpy(out, in, (u8 *)buf, CHACHA20_BLOCK_SIZE);
 		len -= CHACHA20_BLOCK_SIZE;
 		out += CHACHA20_BLOCK_SIZE;
 		in += CHACHA20_BLOCK_SIZE;
 	}
 	if (len) {
-		chacha20_block_generic(buf, (u32 *)state);
+		chacha20_block_generic(ctx, buf);
 		crypto_xor_cpy(out, in, (u8 *)buf, len);
 	}
 }
 
-void chacha20(struct chacha20_ctx *state, u8 *dst, const u8 *src, u32 len,
+void chacha20(struct chacha20_ctx *ctx, u8 *dst, const u8 *src, u32 len,
 	      simd_context_t *simd_context)
 {
-	if (!chacha20_arch(state, dst, src, len, simd_context))
-		chacha20_generic(state, dst, src, len);
+	if (!chacha20_arch(ctx, dst, src, len, simd_context))
+		chacha20_generic(ctx, dst, src, len);
 }
 EXPORT_SYMBOL(chacha20);