[MPTCP] [PATCH v3 04/10] Re-factor and fixes for crypto_hmac_sha1()

[MPTCP] [PATCH v3 04/10] Re-factor and fixes for crypto_hmac_sha1()

[Peter Krystad]

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Re-factor to use parameters specific to MPTCP use case similar to
crypto_key_sha1() and get rid of var args. Also fix endianness issues.

squash to: Add key generation and token tree
and: Add handling of incoming MP_JOIN requests

Signed-off-by: Peter Krystad <peter.krystad(a)linux.intel.com>
---
 net/mptcp/crypto.c   | 23 +++++++++--------------
 net/mptcp/protocol.h |  4 ++--
 net/mptcp/token.c    | 19 ++++++++-----------
 3 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/net/mptcp/crypto.c b/net/mptcp/crypto.c
index 5b764798c536..8b67b11e626c 100644
--- a/net/mptcp/crypto.c
+++ b/net/mptcp/crypto.c
@@ -51,23 +51,23 @@ void crypto_key_sha1(u64 key, u32 *token, u64 *idsn)
 		*idsn = ((u64)mptcp_hashed_key[3] << 32) + mptcp_hashed_key[4];
 }
 
-void crypto_hmac_sha1(u64 key1, u64 key2, u32 *hash_out,
-		      int arg_num, ...)
+void crypto_hmac_sha1(u64 key1, u64 key2, u32 nonce1, u32 nonce2, u32 *hash_out)
 {
 	u32 workspace[SHA_WORKSPACE_WORDS];
 	u8 input[128]; /* 2 512-bit blocks */
 	int i;
 	int index;
-	int length;
-	u8 *msg;
-	va_list list;
 	u8 key_1[8];
 	u8 key_2[8];
+	u8 nonce_1[4];
+	u8 nonce_2[4];
 
 	memset(workspace, 0, sizeof(workspace));
 
 	put_unaligned_be64(key1, key_1);
 	put_unaligned_be64(key2, key_2);
+	put_unaligned_be32(nonce1, nonce_1);
+	put_unaligned_be32(nonce2, nonce_2);
 
 	/* Generate key xored with ipad */
 	memset(input, 0x36, 64);
@@ -76,16 +76,11 @@ void crypto_hmac_sha1(u64 key1, u64 key2, u32 *hash_out,
 	for (i = 0; i < 8; i++)
 		input[i + 8] ^= key_2[i];
 
-	va_start(list, arg_num);
 	index = 64;
-	for (i = 0; i < arg_num; i++) {
-		length = va_arg(list, int);
-		msg = va_arg(list, u8 *);
-		WARN_ON(index + length > 125); /* Message is too long */
-		memcpy(&input[index], msg, length);
-		index += length;
-	}
-	va_end(list);
+	memcpy(&input[index], nonce_1, 4);
+	index = 68;
+	memcpy(&input[index], nonce_2, 4);
+	index = 72;
 
 	input[index] = 0x80; /* Padding: First bit after message = 1 */
 	memset(&input[index + 1], 0, (126 - index));
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index dedd3524e4a2..1d1e89109e98 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -226,8 +226,6 @@ void token_release(u32 token);
 void token_destroy(u32 token);
 
 void crypto_key_sha1(u64 key, u32 *token, u64 *idsn);
-void crypto_hmac_sha1(u64 key1, u64 key2, u32 *hash_out, int arg_num, ...);
-
 static inline void crypto_key_gen_sha1(u64 *key, u32 *token, u64 *idsn)
 {
 	/* we might consider a faster version that computes the key as a
@@ -239,6 +237,8 @@ static inline void crypto_key_gen_sha1(u64 *key, u32 *token, u64 *idsn)
 	get_random_bytes(key, sizeof(u64));
 	crypto_key_sha1(*key, token, idsn);
 }
+void crypto_hmac_sha1(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
+		      u32 *hash_out);
 
 void pm_init(void);
 void pm_new_connection(struct mptcp_sock *msk, int server_side);
diff --git a/net/mptcp/token.c b/net/mptcp/token.c
index e5e0c9689e3a..ef03ef19af98 100644
--- a/net/mptcp/token.c
+++ b/net/mptcp/token.c
@@ -84,12 +84,11 @@ static void new_req_join(struct request_sock *req, struct sock *sk,
 	u8 hmac[MPTCPOPT_HMAC_LEN];
 
 	get_random_bytes(&subflow_req->local_nonce, sizeof(u32));
-	crypto_hmac_sha1(msk->local_key,
-			 msk->remote_key,
-			 (u32 *)hmac, 2,
-			 4, (u8 *)&subflow_req->local_nonce,
-			 4, (u8 *)&subflow_req->remote_nonce);
-	subflow_req->thmac = *(u64 *)hmac;
+	crypto_hmac_sha1(msk->local_key, msk->remote_key,
+			 subflow_req->local_nonce, subflow_req->remote_nonce,
+			 (u32 *)hmac);
+
+	subflow_req->thmac = get_unaligned_be64(hmac);
 	pr_debug("local_nonce=%u, thmac=%llu", subflow_req->local_nonce,
 		 subflow_req->thmac);
 }
@@ -101,11 +100,9 @@ static int new_join_valid(struct request_sock *req, struct sock *sk,
 	struct mptcp_sock *msk = mptcp_sk(sk);
 	u8 hmac[MPTCPOPT_HMAC_LEN];
 
-	crypto_hmac_sha1(msk->remote_key,
-			 msk->local_key,
-			 (u32 *)hmac, 2,
-			 4, (u8 *)&subflow_req->remote_nonce,
-			 4, (u8 *)&subflow_req->local_nonce);
+	crypto_hmac_sha1(msk->remote_key, msk->local_key,
+			 subflow_req->remote_nonce, subflow_req->local_nonce,
+			 (u32 *)hmac);
 
 	return memcmp(hmac, (char *)rx_opt->mptcp.hmac, MPTCPOPT_HMAC_LEN);
 }
-- 
2.17.2

Re: [MPTCP] [PATCH v3 04/10] Re-factor and fixes for crypto_hmac_sha1()

[Matthieu Baerts]

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Hi Peter, Mat, Paolo,

On 08/08/2019 00:44, Peter Krystad wrote:
> Re-factor to use parameters specific to MPTCP use case similar to
> crypto_key_sha1() and get rid of var args. Also fix endianness issues.
> 
> squash to: Add key generation and token tree
> and: Add handling of incoming MP_JOIN requests

Thank you for the patch and the reviews!

- bc31e4f64971: part 1: "squashed" in "mptcp: Add key generation and
token tree"
- f282f6b36b49: part 2: "squahsed" in "mptcp: Add handling of incoming
MP_JOIN requests"
- f7938dd15948..009b132dc29d: result

Cheers,
Matt
-- 
Matthieu Baerts | R&D Engineer
matthieu.baerts(a)tessares.net
Tessares SA | Hybrid Access Solutions
www.tessares.net
1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium