[PATCH v2 4/5] mptcp: use sha256() instead of open coding

[Eric Biggers]

From: Eric Biggers <ebigg...@google.com>

Now that there's a function that calculates the SHA-256 digest of a
buffer in one step, use it instead of sha256_init() + sha256_update() +
sha256_final().

Reviewed-by: Ard Biesheuvel <a...@kernel.org>
Acked-by: Matthieu Baerts <matthieu.bae...@tessares.net>
Cc: mp...@lists.01.org
Cc: Mat Martineau <mathew.j.martin...@linux.intel.com>
Cc: Matthieu Baerts <matthieu.bae...@tessares.net>
Signed-off-by: Eric Biggers <ebigg...@google.com>
---
 net/mptcp/crypto.c | 15 +++------------
 1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/net/mptcp/crypto.c b/net/mptcp/crypto.c
index 3d980713a9e2..82bd2b54d741 100644
--- a/net/mptcp/crypto.c
+++ b/net/mptcp/crypto.c
@@ -32,11 +32,8 @@ void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn)
 {
        __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS];
        __be64 input = cpu_to_be64(key);
-       struct sha256_state state;
 
-       sha256_init(&state);
-       sha256_update(&state, (__force u8 *)&input, sizeof(input));
-       sha256_final(&state, (u8 *)mptcp_hashed_key);
+       sha256((__force u8 *)&input, sizeof(input), (u8 *)mptcp_hashed_key);
 
        if (token)
                *token = be32_to_cpu(mptcp_hashed_key[0]);
@@ -47,7 +44,6 @@ void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn)
 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac)
 {
        u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE];
-       struct sha256_state state;
        u8 key1be[8];
        u8 key2be[8];
        int i;
@@ -67,13 +63,10 @@ void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int 
len, void *hmac)
 
        memcpy(&input[SHA256_BLOCK_SIZE], msg, len);
 
-       sha256_init(&state);
-       sha256_update(&state, input, SHA256_BLOCK_SIZE + len);
-
        /* emit sha256(K1 || msg) on the second input block, so we can
         * reuse 'input' for the last hashing
         */
-       sha256_final(&state, &input[SHA256_BLOCK_SIZE]);
+       sha256(input, SHA256_BLOCK_SIZE + len, &input[SHA256_BLOCK_SIZE]);
 
        /* Prepare second part of hmac */
        memset(input, 0x5C, SHA256_BLOCK_SIZE);
@@ -82,9 +75,7 @@ void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int 
len, void *hmac)
        for (i = 0; i < 8; i++)
                input[i + 8] ^= key2be[i];
 
-       sha256_init(&state);
-       sha256_update(&state, input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE);
-       sha256_final(&state, (u8 *)hmac);
+       sha256(input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE, hmac);
 }
 
 #ifdef CONFIG_MPTCP_HMAC_TEST
-- 
2.27.0