[PATCH v2 15/18] handshake: add functions to save and set IGTK

[John Brandt <brandtwjohn@gmail.com>]

To add MFP support in the AP mode, add utility functions to save the
IGTK and to add the IGTK to handshake messages.
---
 src/handshake.c | 34 ++++++++++++++++++++++++++++++++++
 src/handshake.h |  8 ++++++++
 2 files changed, 42 insertions(+)

diff --git a/src/handshake.c b/src/handshake.c
index ee23dbad..fc1978df 100644
--- a/src/handshake.c
+++ b/src/handshake.c
@@ -838,6 +838,21 @@ void handshake_state_set_gtk(struct handshake_state *s, const uint8_t *key,
 	memcpy(s->gtk_rsc, rsc, 6);
 }
 
+void handshake_state_set_igtk(struct handshake_state *s, const uint8_t *key,
+				unsigned int key_index, const uint8_t *rsc)
+{
+	enum crypto_cipher cipher =
+		ie_rsn_cipher_suite_to_cipher(s->group_management_cipher);
+	int key_len = crypto_cipher_key_len(cipher);
+
+	if (!key_len)
+		return;
+
+	memcpy(s->igtk, key, key_len);
+	s->igtk_index = key_index;
+	memcpy(s->igtk_rsc, rsc, 6);
+}
+
 /*
  * This function performs a match of the RSN/WPA IE obtained from the scan
  * results vs the RSN/WPA IE obtained as part of the 4-way handshake.  If they
@@ -1027,6 +1042,25 @@ void handshake_util_build_gtk_kde(enum crypto_cipher cipher, const uint8_t *key,
 	memcpy(to, key, key_len);
 }
 
+void handshake_util_build_igtk_kde(enum crypto_cipher cipher, const uint8_t *key,
+					unsigned int key_index, uint8_t *to)
+{
+	size_t key_len = crypto_cipher_key_len(cipher);
+
+	*to++ = IE_TYPE_VENDOR_SPECIFIC;
+	*to++ = 12 + key_len;
+	l_put_be32(HANDSHAKE_KDE_IGTK, to);
+	to += 4;
+	*to++ = key_index;
+	*to++ = 0;
+
+	/** Initialize PN to zero **/
+	memset(to, 0, 6);
+	to += 6;
+
+	memcpy(to, key, key_len);
+}
+
 static const uint8_t *handshake_state_get_ft_fils_kek(struct handshake_state *s,
 						size_t *len)
 {
diff --git a/src/handshake.h b/src/handshake.h
index 62118fe2..8a356e6b 100644
--- a/src/handshake.h
+++ b/src/handshake.h
@@ -150,8 +150,11 @@ struct handshake_state {
 	uint8_t r1khid[6];
 	uint8_t gtk[32];
 	uint8_t gtk_rsc[6];
+	uint8_t igtk[32];
+	uint8_t igtk_rsc[6];
 	uint8_t proto_version : 2;
 	unsigned int gtk_index;
+	unsigned int igtk_index;
 	uint8_t active_tk_index;
 	struct erp_cache_entry *erp_cache;
 	bool support_ip_allocation : 1;
@@ -288,6 +291,9 @@ bool handshake_decode_fte_key(struct handshake_state *s, const uint8_t *wrapped,
 void handshake_state_set_gtk(struct handshake_state *s, const uint8_t *key,
 				unsigned int key_index, const uint8_t *rsc);
 
+void handshake_state_set_igtk(struct handshake_state *s, const uint8_t *key,
+				unsigned int key_index, const uint8_t *rsc);
+
 void handshake_state_set_chandef(struct handshake_state *s,
 					struct band_chandef *chandef);
 int handshake_state_verify_oci(struct handshake_state *s, const uint8_t *oci,
@@ -307,5 +313,7 @@ const uint8_t *handshake_util_find_pmkid_kde(const uint8_t *data,
 					size_t data_len);
 void handshake_util_build_gtk_kde(enum crypto_cipher cipher, const uint8_t *key,
 					unsigned int key_index, uint8_t *to);
+void handshake_util_build_igtk_kde(enum crypto_cipher cipher, const uint8_t *key,
+					unsigned int key_index, uint8_t *to);
 
 DEFINE_CLEANUP_FUNC(handshake_state_free);
-- 
2.45.0