From: Tobias Brunner <tobias@strongswan.org>
Date: Tue, 2 Jul 2019 13:01:26 +0000 (+0200)
Subject: keymat_v2: Add method to calculate IntAuth for IKE_INTERMEDIATE exchanges
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df886ea9717c6206f5fbfb9bd57a55a881dc79c5;p=thirdparty%2Fstrongswan.git

keymat_v2: Add method to calculate IntAuth for IKE_INTERMEDIATE exchanges
---

diff --git a/src/charon-tkm/src/tkm/tkm_keymat.c b/src/charon-tkm/src/tkm/tkm_keymat.c
index 6e79c639eb..2d3c1030e5 100644
--- a/src/charon-tkm/src/tkm/tkm_keymat.c
+++ b/src/charon-tkm/src/tkm/tkm_keymat.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 Tobias Brunner
+ * Copyright (C) 2015-2019 Tobias Brunner
  * Copyright (C) 2012 Reto Buerki
  * Copyright (C) 2012 Adrian-Ken Rueegsegger
  *
@@ -246,6 +246,14 @@ METHOD(keymat_t, get_aead, aead_t*,
 	return this->aead;
 }
 
+METHOD(keymat_v2_t, get_int_auth, bool,
+	private_tkm_keymat_t *this, bool verify, chunk_t data, chunk_t prev,
+	chunk_t *auth)
+{
+	DBG1(DBG_IKE, "TKM doesn't support IntAuth calculation");
+	return FALSE;
+}
+
 METHOD(keymat_v2_t, get_auth_octets, bool,
 	private_tkm_keymat_t *this, bool verify, chunk_t ike_sa_init,
 	chunk_t nonce, chunk_t ppk, identification_t *id, char reserved[3],
@@ -388,6 +396,7 @@ tkm_keymat_t *tkm_keymat_create(bool initiator)
 				.derive_ike_keys_ppk = (void*)return_false,
 				.derive_child_keys = _derive_child_keys,
 				.get_skd = _get_skd,
+				.get_int_auth = _get_int_auth,
 				.get_auth_octets = _get_auth_octets,
 				.get_psk_sig = _get_psk_sig,
 				.add_hash_algorithm = _add_hash_algorithm,
diff --git a/src/libcharon/sa/ikev2/keymat_v2.c b/src/libcharon/sa/ikev2/keymat_v2.c
index c8a9c7117d..42ce6c67bd 100644
--- a/src/libcharon/sa/ikev2/keymat_v2.c
+++ b/src/libcharon/sa/ikev2/keymat_v2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 Tobias Brunner
+ * Copyright (C) 2015-2019 Tobias Brunner
  * Copyright (C) 2008 Martin Willi
  *
  * Copyright (C) secunet Security Networks AG
@@ -261,6 +261,7 @@ METHOD(keymat_v2_t, derive_ike_keys, bool,
 		return FALSE;
 	}
 	this->prf_alg = prf_alg;
+	DESTROY_IF(this->prf);
 	this->prf = lib->crypto->create_prf(lib->crypto, this->prf_alg);
 	if (!this->prf)
 	{
@@ -656,6 +657,27 @@ METHOD(keymat_t, get_aead, aead_t*,
 	return in ? this->aead_in : this->aead_out;
 }
 
+METHOD(keymat_v2_t, get_int_auth, bool,
+	private_keymat_v2_t *this, bool verify, chunk_t data, chunk_t prev,
+	chunk_t *auth)
+{
+	chunk_t skp;
+
+	skp = verify ? this->skp_verify : this->skp_build;
+
+	DBG3(DBG_IKE, "IntAuth_N-1 %B", &prev);
+	DBG3(DBG_IKE, "IntAuth_A|P %B", &data);
+	DBG4(DBG_IKE, "SK_p %B", &skp);
+	data = chunk_cata("cc", prev, data);
+	if (!this->prf->set_key(this->prf, skp) ||
+		!this->prf->allocate_bytes(this->prf, data, auth))
+	{
+		return FALSE;
+	}
+	DBG3(DBG_IKE, "IntAuth_N = prf(Sk_px, data) %B", auth);
+	return TRUE;
+}
+
 METHOD(keymat_v2_t, get_auth_octets, bool,
 	private_keymat_v2_t *this, bool verify, chunk_t ike_sa_init,
 	chunk_t nonce, chunk_t ppk, identification_t *id, char reserved[3],
@@ -749,7 +771,6 @@ failure:
 	chunk_free(&octets);
 	chunk_free(&key);
 	return success;
-
 }
 
 METHOD(keymat_v2_t, hash_algorithm_supported, bool,
@@ -805,6 +826,7 @@ keymat_v2_t *keymat_v2_create(bool initiator)
 			.derive_ike_keys_ppk = _derive_ike_keys_ppk,
 			.derive_child_keys = _derive_child_keys,
 			.get_skd = _get_skd,
+			.get_int_auth = _get_int_auth,
 			.get_auth_octets = _get_auth_octets,
 			.get_psk_sig = _get_psk_sig,
 			.add_hash_algorithm = _add_hash_algorithm,
diff --git a/src/libcharon/sa/ikev2/keymat_v2.h b/src/libcharon/sa/ikev2/keymat_v2.h
index 60bac653b7..f2f0bec1ce 100644
--- a/src/libcharon/sa/ikev2/keymat_v2.h
+++ b/src/libcharon/sa/ikev2/keymat_v2.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011-2015 Tobias Brunner
+ * Copyright (C) 2011-2019 Tobias Brunner
  *
  * Copyright (C) secunet Security Networks AG
  *
@@ -91,6 +91,7 @@ struct keymat_v2_t {
 							  chunk_t nonce_i, chunk_t nonce_r,
 							  chunk_t *encr_i, chunk_t *integ_i,
 							  chunk_t *encr_r, chunk_t *integ_r);
+
 	/**
 	 * Get SKd to pass to derive_ikey_keys() during rekeying.
 	 *
@@ -99,6 +100,22 @@ struct keymat_v2_t {
 	 */
 	pseudo_random_function_t (*get_skd)(keymat_v2_t *this, chunk_t *skd);
 
+	/**
+	 * Generate data for signed octets when using IKE_INTEMEDIATE exchanges.
+	 *
+	 * The supplied chunk must contain the IKE header until the end of the
+	 * Encrypted Payload header followed by the plaintext contents of the
+	 * latter.
+	 *
+	 * @param verify		TRUE as recipient, FALSE as sender
+	 * @param data			IKE_INTERMEDIATE packet data
+	 * @param prev			previous IntAuth value
+	 * @param[out] auth		IntAuth data to be used later with get_auth_octets()
+	 * @return				TRUE if octets created successfully
+	 */
+	bool (*get_int_auth)(keymat_v2_t *this, bool verify, chunk_t data,
+						 chunk_t prev, chunk_t *auth);
+
 	/**
 	 * Generate octets to use for authentication procedure (RFC4306 2.15).
 	 *