From: Andrey Kartashev <andrey.kartashev@xxxxxxxxxxxxx>
There is already partial support of GCM-AES-256. It is possible to
enable this mode by setting 'kay->macsec_csindex = 1;' in
ieee802_1x_kay_init() function, but generated key contain only 128 bits
of data while other 128 bits are in 0.
This patch enables KaY to generate full 256bit key from same 128bit CAK.
Signed-off-by: Andrey Kartashev <andrey.kartashev@xxxxxxxxxxxxx>
---
src/pae/ieee802_1x_kay.c | 12 ++++++------
src/pae/ieee802_1x_key.c | 6 ++++--
src/pae/ieee802_1x_key.h | 2 +-
3 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/src/pae/ieee802_1x_kay.c b/src/pae/ieee802_1x_kay.c
index a4771b792..3a31bdf93 100644
--- a/src/pae/ieee802_1x_kay.c
+++ b/src/pae/ieee802_1x_kay.c
@@ -2039,12 +2039,12 @@ ieee802_1x_kay_generate_new_sak(struct ieee802_1x_mka_participant *participant)
ctx_offset += sizeof(participant->mi);
os_memcpy(context + ctx_offset, &kay->dist_kn, sizeof(kay->dist_kn));
- if (key_len == 16) {
- ieee802_1x_sak_128bits_aes_cmac(participant->cak.key,
- context, ctx_len, key);
- } else if (key_len == 32) {
- ieee802_1x_sak_128bits_aes_cmac(participant->cak.key,
- context, ctx_len, key);
+ if ((key_len == 16)||(key_len == 32)) {
+ if (ieee802_1x_sak_128bits_aes_cmac(participant->cak.key,
+ context, ctx_len, key, key_len)) {
+ wpa_printf(MSG_ERROR, "KaY: Failed to generate SAK");
+ goto fail;
+ }
} else {
wpa_printf(MSG_ERROR, "KaY: SAK Length not support");
goto fail;
diff --git a/src/pae/ieee802_1x_key.c b/src/pae/ieee802_1x_key.c
index 9a8d923d1..3ed9d1645 100644
--- a/src/pae/ieee802_1x_key.c
+++ b/src/pae/ieee802_1x_key.c
@@ -183,7 +183,9 @@ int ieee802_1x_icv_128bits_aes_cmac(const u8 *ick, const u8 *msg,
* SAK = KDF(Key, Label, KS-nonce | MI-value list | KN, SAKLength)
*/
int ieee802_1x_sak_128bits_aes_cmac(const u8 *cak, const u8 *ctx,
- size_t ctx_bytes, u8 *sak)
+ size_t ctx_bytes, u8 *sak, size_t sak_bytes)
{
- return aes_kdf_128(cak, "IEEE8021 SAK", ctx, ctx_bytes * 8, 128, sak);
+ return aes_kdf_128(cak, "IEEE8021 SAK", ctx, ctx_bytes * 8,
+ sak_bytes * 8, sak);
}
+
diff --git a/src/pae/ieee802_1x_key.h b/src/pae/ieee802_1x_key.h
index ea318ea4d..1be5df07e 100644
--- a/src/pae/ieee802_1x_key.h
+++ b/src/pae/ieee802_1x_key.h
@@ -21,6 +21,6 @@ int ieee802_1x_ick_128bits_aes_cmac(const u8 *cak, const u8 *ckn,
int ieee802_1x_icv_128bits_aes_cmac(const u8 *ick, const u8 *msg,
size_t msg_bytes, u8 *icv);
int ieee802_1x_sak_128bits_aes_cmac(const u8 *cak, const u8 *ctx,
- size_t ctx_bytes, u8 *sak);
+ size_t ctx_bytes, u8 *sak, size_t sak_bytes);
#endif /* IEEE802_1X_KEY_H */
--
2.17.1
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