From: Tobias Brunner <tobias@strongswan.org>
Date: Fri, 23 Jul 2021 12:53:15 +0000 (+0200)
Subject: botan: Move shared secret calculation to get_shared_secret()
X-Git-Tag: 5.9.7dr2~1^2~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=31f467d70b6f7adf9f8d92d1ba94b306e8f6e84b;p=thirdparty%2Fstrongswan.git

botan: Move shared secret calculation to get_shared_secret()
---

diff --git a/src/libstrongswan/plugins/botan/botan_diffie_hellman.c b/src/libstrongswan/plugins/botan/botan_diffie_hellman.c
index 4b54175858..cacc220d65 100644
--- a/src/libstrongswan/plugins/botan/botan_diffie_hellman.c
+++ b/src/libstrongswan/plugins/botan/botan_diffie_hellman.c
@@ -54,7 +54,12 @@ struct private_botan_diffie_hellman_t {
 	/**
 	 * Private key
 	 */
-	botan_privkey_t dh_key;
+	botan_privkey_t key;
+
+	/**
+	 * Public key value provided by peer
+	 */
+	chunk_t pubkey;
 
 	/**
 	 * Diffie hellman shared secret
@@ -84,8 +89,8 @@ bool load_private_key(private_botan_diffie_hellman_t *this, chunk_t value)
 		return FALSE;
 	}
 
-	if (botan_privkey_destroy(this->dh_key) ||
-		botan_privkey_load_dh(&this->dh_key, this->p, this->g, xa))
+	if (botan_privkey_destroy(this->key) ||
+		botan_privkey_load_dh(&this->key, this->p, this->g, xa))
 	{
 		botan_mp_destroy(xa);
 		return FALSE;
@@ -102,9 +107,9 @@ METHOD(key_exchange_t, set_public_key, bool,
 		return FALSE;
 	}
 
-	chunk_clear(&this->shared_secret);
-
-	return botan_dh_key_derivation(this->dh_key, value, &this->shared_secret);
+	chunk_clear(&this->pubkey);
+	this->pubkey = chunk_clone(value);
+	return TRUE;
 }
 
 METHOD(key_exchange_t, get_public_key, bool,
@@ -113,14 +118,14 @@ METHOD(key_exchange_t, get_public_key, bool,
 	*value = chunk_empty;
 
 	/* get key size of public key first */
-	if (botan_pk_op_key_agreement_export_public(this->dh_key, NULL, &value->len)
+	if (botan_pk_op_key_agreement_export_public(this->key, NULL, &value->len)
 		!= BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE)
 	{
 		return FALSE;
 	}
 
 	*value = chunk_alloc(value->len);
-	if (botan_pk_op_key_agreement_export_public(this->dh_key, value->ptr,
+	if (botan_pk_op_key_agreement_export_public(this->key, value->ptr,
 												&value->len))
 	{
 		chunk_clear(value);
@@ -139,7 +144,8 @@ METHOD(key_exchange_t, set_private_key, bool,
 METHOD(key_exchange_t, get_shared_secret, bool,
 	private_botan_diffie_hellman_t *this, chunk_t *secret)
 {
-	if (!this->shared_secret.len)
+	if (!this->shared_secret.len &&
+		!botan_dh_key_derivation(this->key, this->pubkey, &this->shared_secret))
 	{
 		return FALSE;
 	}
@@ -158,8 +164,9 @@ METHOD(key_exchange_t, destroy, void,
 {
 	botan_mp_destroy(this->p);
 	botan_mp_destroy(this->g);
-	botan_privkey_destroy(this->dh_key);
+	botan_privkey_destroy(this->key);
 	chunk_clear(&this->shared_secret);
+	chunk_clear(&this->pubkey);
 	free(this);
 }
 
diff --git a/src/libstrongswan/plugins/botan/botan_ec_diffie_hellman.c b/src/libstrongswan/plugins/botan/botan_ec_diffie_hellman.c
index 871e58c565..5ebaca4c44 100644
--- a/src/libstrongswan/plugins/botan/botan_ec_diffie_hellman.c
+++ b/src/libstrongswan/plugins/botan/botan_ec_diffie_hellman.c
@@ -60,6 +60,11 @@ struct private_botan_ec_diffie_hellman_t {
 	 */
 	botan_privkey_t key;
 
+	/**
+	 * Public key value provided by peer
+	 */
+	chunk_t pubkey;
+
 	/**
 	 * Shared secret
 	 */
@@ -74,12 +79,10 @@ METHOD(key_exchange_t, set_public_key, bool,
 		return FALSE;
 	}
 
-	chunk_clear(&this->shared_secret);
-
+	chunk_clear(&this->pubkey);
 	/* prepend 0x04 to indicate uncompressed point format */
-	value = chunk_cata("cc", chunk_from_chars(0x04), value);
-
-	return botan_dh_key_derivation(this->key, value, &this->shared_secret);
+	this->pubkey = chunk_cat("cc", chunk_from_chars(0x04), value);
+	return TRUE;
 }
 
 METHOD(key_exchange_t, get_public_key, bool,
@@ -135,7 +138,8 @@ METHOD(key_exchange_t, set_private_key, bool,
 METHOD(key_exchange_t, get_shared_secret, bool,
 	private_botan_ec_diffie_hellman_t *this, chunk_t *secret)
 {
-	if (!this->shared_secret.len)
+	if (!this->shared_secret.len &&
+		!botan_dh_key_derivation(this->key, this->pubkey, &this->shared_secret))
 	{
 		return FALSE;
 	}
@@ -154,6 +158,7 @@ METHOD(key_exchange_t, destroy, void,
 {
 	botan_privkey_destroy(this->key);
 	chunk_clear(&this->shared_secret);
+	chunk_clear(&this->pubkey);
 	free(this);
 }
 
diff --git a/src/libstrongswan/plugins/botan/botan_x25519.c b/src/libstrongswan/plugins/botan/botan_x25519.c
index 184ce2e8da..8323e555dc 100644
--- a/src/libstrongswan/plugins/botan/botan_x25519.c
+++ b/src/libstrongswan/plugins/botan/botan_x25519.c
@@ -49,6 +49,11 @@ struct private_diffie_hellman_t {
 	 */
 	botan_privkey_t key;
 
+	/**
+	 * Public key value provided by peer
+	 */
+	chunk_t pubkey;
+
 	/**
 	 * Shared secret
 	 */
@@ -63,9 +68,9 @@ METHOD(key_exchange_t, set_public_key, bool,
 		return FALSE;
 	}
 
-	chunk_clear(&this->shared_secret);
-
-	return botan_dh_key_derivation(this->key, value, &this->shared_secret);
+	chunk_clear(&this->pubkey);
+	this->pubkey = chunk_clone(value);
+	return TRUE;
 }
 
 METHOD(key_exchange_t, get_public_key, bool,
@@ -113,7 +118,8 @@ METHOD(key_exchange_t, set_private_key, bool,
 METHOD(key_exchange_t, get_shared_secret, bool,
 	private_diffie_hellman_t *this, chunk_t *secret)
 {
-	if (!this->shared_secret.len)
+	if (!this->shared_secret.len &&
+		!botan_dh_key_derivation(this->key, this->pubkey, &this->shared_secret))
 	{
 		return FALSE;
 	}
@@ -132,6 +138,7 @@ METHOD(key_exchange_t, destroy, void,
 {
 	botan_privkey_destroy(this->key);
 	chunk_clear(&this->shared_secret);
+	chunk_clear(&this->pubkey);
 	free(this);
 }