1 files changed, 35 insertions, 22 deletions

diff --git a/include/crypto/chacha.h b/include/crypto/chacha.h
index 424dd818..c9d23ab3 100644
--- a/include/crypto/chacha.h
+++ b/include/crypto/chacha.h
@@ -12,7 +12,13 @@
 #define CHACHA_IV_SIZE	16
 #define CHACHA_KEY_SIZE	32
 #define CHACHA_BLOCK_SIZE	64
-#define CHACHA_STATE_WORDS	(CHACHA_BLOCK_SIZE / sizeof(u32))
+
+#define CHACHA_KEY_WORDS	8
+#define CHACHA_STATE_WORDS	16
+
+struct chacha_state {
+	u32 x[CHACHA_STATE_WORDS];
+};
 
 enum chacha_constants { /* expand 32-byte k */
 	CHACHA_CONSTANT_EXPA = 0x61707865U,
@@ -21,38 +27,40 @@ enum chacha_constants { /* expand 32-byte k */
 	CHACHA_CONSTANT_TE_K = 0x6b206574U
 };
 
-static inline void chacha_init_consts(u32 *state)
+static inline void chacha_init_consts(struct chacha_state *state)
 {
-	state[0]  = CHACHA_CONSTANT_EXPA;
-	state[1]  = CHACHA_CONSTANT_ND_3;
-	state[2]  = CHACHA_CONSTANT_2_BY;
-	state[3]  = CHACHA_CONSTANT_TE_K;
+	state->x[0]  = CHACHA_CONSTANT_EXPA;
+	state->x[1]  = CHACHA_CONSTANT_ND_3;
+	state->x[2]  = CHACHA_CONSTANT_2_BY;
+	state->x[3]  = CHACHA_CONSTANT_TE_K;
 }
 
-static inline void chacha_init(u32 *state, const u32 *key, const u8 *iv)
+static inline void chacha_init(struct chacha_state *state,
+			       const u32 key[CHACHA_KEY_WORDS],
+			       const u8 iv[CHACHA_IV_SIZE])
 {
 	chacha_init_consts(state);
-	state[4]  = key[0];
-	state[5]  = key[1];
-	state[6]  = key[2];
-	state[7]  = key[3];
-	state[8]  = key[4];
-	state[9]  = key[5];
-	state[10] = key[6];
-	state[11] = key[7];
-	state[12] = get_unaligned_le32(iv +  0);
-	state[13] = get_unaligned_le32(iv +  4);
-	state[14] = get_unaligned_le32(iv +  8);
-	state[15] = get_unaligned_le32(iv + 12);
+	state->x[4]  = key[0];
+	state->x[5]  = key[1];
+	state->x[6]  = key[2];
+	state->x[7]  = key[3];
+	state->x[8]  = key[4];
+	state->x[9]  = key[5];
+	state->x[10] = key[6];
+	state->x[11] = key[7];
+	state->x[12] = get_unaligned_le32(iv +  0);
+	state->x[13] = get_unaligned_le32(iv +  4);
+	state->x[14] = get_unaligned_le32(iv +  8);
+	state->x[15] = get_unaligned_le32(iv + 12);
 }
 
 #include <sodium/crypto_stream_chacha20.h>
 
-static inline void chacha20_crypt(u32 *state, u8 *dst, const u8 *src,
+static inline void chacha20_crypt(struct chacha_state *state, u8 *dst, const u8 *src,
 				  unsigned int bytes)
 {
-	u32 *key = state + 4;
-	u32 *iv  = state + 12;
+	u32 *key = state->x + 4;
+	u32 *iv  = state->x + 12;
 	int ret = crypto_stream_chacha20_xor_ic(dst, src, bytes,
 						(void *) &iv[2],
 						iv[0] | ((u64) iv[1] << 32),
@@ -60,4 +68,9 @@ static inline void chacha20_crypt(u32 *state, u8 *dst, const u8 *src,
 	BUG_ON(ret);
 }
 
+static inline void chacha_zeroize_state(struct chacha_state *state)
+{
+	memzero_explicit(state, sizeof(*state));
+}
+
 #endif