@@ -3,6 +3,7 @@ config MPTCP
bool "MPTCP: Multipath TCP"
depends on INET
select SKB_EXTENSIONS
+ select CRYPTO_LIB_SHA256
help
Multipath TCP (MPTCP) connections send and receive data over multiple
subflows in order to utilize multiple network paths. Each subflow
@@ -14,3 +15,12 @@ config MPTCP_IPV6
depends on MPTCP
select IPV6
default y
+
+config MPTCP_HMAC_TEST
+ bool "Tests for MPTCP HMAC implementation"
+ default n
+ help
+ This option enable boot time self-test for the HMAC implementation
+ used by the MPTCP code
+
+ Say N if you are unsure.
@@ -21,67 +21,36 @@
*/
#include <linux/kernel.h>
-#include <linux/cryptohash.h>
+#include <crypto/sha.h>
#include <asm/unaligned.h>
#include "protocol.h"
-struct sha1_state {
- u32 workspace[SHA_WORKSPACE_WORDS];
- u32 digest[SHA_DIGEST_WORDS];
- unsigned int count;
-};
-
-static void sha1_init(struct sha1_state *state)
-{
- sha_init(state->digest);
- state->count = 0;
-}
-
-static void sha1_update(struct sha1_state *state, u8 *input)
-{
- sha_transform(state->digest, input, state->workspace);
- state->count += SHA_MESSAGE_BYTES;
-}
-
-static void sha1_pad_final(struct sha1_state *state, u8 *input,
- unsigned int length, __be32 *mptcp_hashed_key)
-{
- int i;
-
- input[length] = 0x80;
- memset(&input[length + 1], 0, SHA_MESSAGE_BYTES - length - 9);
- put_unaligned_be64((length + state->count) << 3,
- &input[SHA_MESSAGE_BYTES - 8]);
-
- sha_transform(state->digest, input, state->workspace);
- for (i = 0; i < SHA_DIGEST_WORDS; ++i)
- put_unaligned_be32(state->digest[i], &mptcp_hashed_key[i]);
-
- memzero_explicit(state->workspace, SHA_WORKSPACE_WORDS << 2);
-}
+#define SHA256_DIGEST_WORDS (SHA256_DIGEST_SIZE / 4)
void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn)
{
- __be32 mptcp_hashed_key[SHA_DIGEST_WORDS];
- u8 input[SHA_MESSAGE_BYTES];
- struct sha1_state state;
+ __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS];
+ __be64 input = cpu_to_be64(key);
+ struct sha256_state state;
- sha1_init(&state);
- put_unaligned_be64(key, input);
- sha1_pad_final(&state, input, 8, mptcp_hashed_key);
+ sha256_init(&state);
+ sha256_update(&state, (__force u8 *)&input, sizeof(input));
+ sha256_final(&state, (u8 *)mptcp_hashed_key);
if (token)
*token = be32_to_cpu(mptcp_hashed_key[0]);
if (idsn)
- *idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[3]));
+ *idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[6]));
}
void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
- u32 *hash_out)
+ void *hmac)
{
- u8 input[SHA_MESSAGE_BYTES * 2];
- struct sha1_state state;
+ u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE];
+ __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS];
+ __be32 *hash_out = (__force __be32 *)hmac;
+ struct sha256_state state;
u8 key1be[8];
u8 key2be[8];
int i;
@@ -96,17 +65,16 @@ void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
for (i = 0; i < 8; i++)
input[i + 8] ^= key2be[i];
- put_unaligned_be32(nonce1, &input[SHA_MESSAGE_BYTES]);
- put_unaligned_be32(nonce2, &input[SHA_MESSAGE_BYTES + 4]);
+ put_unaligned_be32(nonce1, &input[SHA256_BLOCK_SIZE]);
+ put_unaligned_be32(nonce2, &input[SHA256_BLOCK_SIZE + 4]);
- sha1_init(&state);
- sha1_update(&state, input);
+ sha256_init(&state);
+ sha256_update(&state, input, SHA256_BLOCK_SIZE + 8);
/* emit sha256(K1 || msg) on the second input block, so we can
* reuse 'input' for the last hashing
*/
- sha1_pad_final(&state, &input[SHA_MESSAGE_BYTES], 8,
- (__force __be32 *)&input[SHA_MESSAGE_BYTES]);
+ sha256_final(&state, &input[SHA256_BLOCK_SIZE]);
/* Prepare second part of hmac */
memset(input, 0x5C, SHA_MESSAGE_BYTES);
@@ -115,8 +83,70 @@ void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
for (i = 0; i < 8; i++)
input[i + 8] ^= key2be[i];
- sha1_init(&state);
- sha1_update(&state, input);
- sha1_pad_final(&state, &input[SHA_MESSAGE_BYTES], SHA_DIGEST_WORDS << 2,
- (__be32 *)hash_out);
+ sha256_init(&state);
+ sha256_update(&state, input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE);
+ sha256_final(&state, (u8 *)mptcp_hashed_key);
+
+ /* takes only first 160 bits */
+ for (i = 0; i < 5; i++)
+ hash_out[i] = mptcp_hashed_key[i];
+}
+
+#ifdef CONFIG_MPTCP_HMAC_TEST
+struct test_cast {
+ char *key;
+ char *msg;
+ char *result;
+};
+
+/* we can't reuse RFC 4231 test vectors, as we have constraint on the
+ * input and key size, and we truncate the output.
+ */
+static struct test_cast tests[] = {
+ {
+ .key = "0b0b0b0b0b0b0b0b",
+ .msg = "48692054",
+ .result = "8385e24fb4235ac37556b6b886db106284a1da67",
+ },
+ {
+ .key = "aaaaaaaaaaaaaaaa",
+ .msg = "dddddddd",
+ .result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492",
+ },
+ {
+ .key = "0102030405060708",
+ .msg = "cdcdcdcd",
+ .result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6",
+ },
+};
+
+static int __init test_mptcp_crypto(void)
+{
+ char hmac[20], hmac_hex[41];
+ u32 nonce1, nonce2;
+ u64 key1, key2;
+ int i, j;
+
+ for (i = 0; i < ARRAY_SIZE(tests); ++i) {
+ /* mptcp hmap will convert to be before computing the hmac */
+ key1 = be64_to_cpu(*((__be64 *)&tests[i].key[0]));
+ key2 = be64_to_cpu(*((__be64 *)&tests[i].key[8]));
+ nonce1 = be32_to_cpu(*((__be32 *)&tests[i].msg[0]));
+ nonce2 = be32_to_cpu(*((__be32 *)&tests[i].msg[4]));
+
+ mptcp_crypto_hmac_sha(key1, key2, nonce1, nonce2, hmac);
+ for (j = 0; j < 20; ++j)
+ sprintf(&hmac_hex[j << 1], "%02x", hmac[j] & 0xff);
+ hmac_hex[40] = 0;
+
+ if (memcmp(hmac_hex, tests[i].result, 40))
+ pr_err("test %d failed, got %s expected %s", i,
+ hmac_hex, tests[i].result);
+ else
+ pr_info("test %d [ ok ]", i);
+ }
+ return 0;
}
+
+late_initcall(test_mptcp_crypto);
+#endif
@@ -9,6 +9,11 @@
#include <net/mptcp.h>
#include "protocol.h"
+static bool mptcp_cap_flag_sha256(u8 flags)
+{
+ return (flags & MPTCP_CAP_FLAG_MASK) == MPTCP_CAP_HMAC_SHA256;
+}
+
void mptcp_parse_option(const unsigned char *ptr, int opsize,
struct tcp_options_received *opt_rx)
{
@@ -29,7 +34,7 @@ void mptcp_parse_option(const unsigned char *ptr, int opsize,
break;
flags = *ptr++;
- if (!((flags & MPTCP_CAP_FLAG_MASK) == MPTCP_CAP_HMAC_SHA1) ||
+ if (!mptcp_cap_flag_sha256(flags) ||
(flags & MPTCP_CAP_EXTENSIBILITY))
break;
@@ -399,7 +404,7 @@ void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts)
*ptr++ = htonl((TCPOPT_MPTCP << 24) | (len << 16) |
(MPTCPOPT_MP_CAPABLE << 12) |
(MPTCP_SUPPORTED_VERSION << 8) |
- MPTCP_CAP_HMAC_SHA1);
+ MPTCP_CAP_HMAC_SHA256);
put_unaligned_be64(opts->sndr_key, ptr);
ptr += 2;
if (OPTION_MPTCP_MPC_ACK & opts->suboptions) {
@@ -43,7 +43,7 @@
#define MPTCP_VERSION_MASK (0x0F)
#define MPTCP_CAP_CHECKSUM_REQD BIT(7)
#define MPTCP_CAP_EXTENSIBILITY BIT(6)
-#define MPTCP_CAP_HMAC_SHA1 BIT(0)
+#define MPTCP_CAP_HMAC_SHA256 BIT(0)
#define MPTCP_CAP_FLAG_MASK (0x3F)
/* MPTCP DSS flags */
@@ -216,7 +216,7 @@ static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn)
}
void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
- u32 *hash_out);
+ void *hash_out);
static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
{