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openssl: Move shared secret calculation to get_shared_secret()

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This is a change from the multi-KE branch.
This commit is contained in:
Tobias Brunner
2022-04-14 19:05:44 +02:00
parent 94a3563c68
commit 1c1213f4b6
4 changed files with 51 additions and 73 deletions
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src/libstrongswan/plugins/openssl/openssl_diffie_hellman.c
+18 -26
View File
@@ -63,11 +63,6 @@ struct private_openssl_diffie_hellman_t {
* Shared secret
*/
chunk_t shared_secret;
/**
* True if shared secret is computed
*/
bool computed;
};
METHOD(diffie_hellman_t, get_my_public_value, bool,
@@ -85,15 +80,24 @@ METHOD(diffie_hellman_t, get_my_public_value, bool,
METHOD(diffie_hellman_t, get_shared_secret, bool,
private_openssl_diffie_hellman_t *this, chunk_t *secret)
{
if (!this->computed)
int len;
if (!this->shared_secret.len)
{
return FALSE;
this->shared_secret = chunk_alloc(DH_size(this->dh));
memset(this->shared_secret.ptr, 0xFF, this->shared_secret.len);
len = DH_compute_key(this->shared_secret.ptr, this->pub_key, this->dh);
if (len < 0)
{
DBG1(DBG_LIB, "DH shared secret computation failed");
chunk_clear(&this->shared_secret);
return FALSE;
}
this->shared_secret.len = len;
}
/* shared secret should requires a len according the DH group */
*secret = chunk_alloc(DH_size(this->dh));
memset(secret->ptr, 0, secret->len);
memcpy(secret->ptr + secret->len - this->shared_secret.len,
this->shared_secret.ptr, this->shared_secret.len);
/* shared secret requires a length according to the DH group */
*secret = chunk_copy_pad(chunk_alloc(DH_size(this->dh)),
this->shared_secret, 0);
return TRUE;
}
@@ -101,25 +105,16 @@ METHOD(diffie_hellman_t, get_shared_secret, bool,
METHOD(diffie_hellman_t, set_other_public_value, bool,
private_openssl_diffie_hellman_t *this, chunk_t value)
{
int len;
if (!diffie_hellman_verify_value(this->group, value))
{
return FALSE;
}
BN_bin2bn(value.ptr, value.len, this->pub_key);
chunk_clear(&this->shared_secret);
this->shared_secret.ptr = malloc(DH_size(this->dh));
memset(this->shared_secret.ptr, 0xFF, this->shared_secret.len);
len = DH_compute_key(this->shared_secret.ptr, this->pub_key, this->dh);
if (len < 0)
if (!BN_bin2bn(value.ptr, value.len, this->pub_key))
{
DBG1(DBG_LIB, "DH shared secret computation failed");
return FALSE;
}
this->shared_secret.len = len;
this->computed = TRUE;
chunk_clear(&this->shared_secret);
return TRUE;
}
@@ -136,7 +131,6 @@ METHOD(diffie_hellman_t, set_private_value, bool,
return FALSE;
}
chunk_clear(&this->shared_secret);
this->computed = FALSE;
return DH_generate_key(this->dh);
}
return FALSE;
@@ -220,9 +214,7 @@ openssl_diffie_hellman_t *openssl_diffie_hellman_create(
}
this->group = group;
this->computed = FALSE;
this->pub_key = BN_new();
this->shared_secret = chunk_empty;
if (group == MODP_CUSTOM)
{
src/libstrongswan/plugins/openssl/openssl_ec_diffie_hellman.c
+18 -25
View File
@@ -51,6 +51,11 @@ struct private_openssl_ec_diffie_hellman_t {
*/
EVP_PKEY *key;
/**
* Public key provided by peer
*/
EVP_PKEY *pub;
/**
* EC group
*/
@@ -186,50 +191,35 @@ error:
METHOD(diffie_hellman_t, set_other_public_value, bool,
private_openssl_ec_diffie_hellman_t *this, chunk_t value)
{
EVP_PKEY *pub = NULL;
chunk_clear(&this->shared_secret);
this->computed = FALSE;
if (!diffie_hellman_verify_value(this->group, value))
{
return FALSE;
}
pub = EVP_PKEY_new();
if (!pub)
if (!this->pub)
{
goto error;
this->pub = EVP_PKEY_new();
}
#if OPENSSL_VERSION_NUMBER < 0x1010000fL
if (!chunk2ecp(this->ec_group, value, pub))
if (!chunk2ecp(this->ec_group, value, this->pub))
{
DBG1(DBG_LIB, "ECDH public value is malformed");
goto error;
return FALSE;
}
#else
/* OpenSSL expects the pubkey in the format specified in section 2.3.4 of
* SECG SEC 1, i.e. prefixed with 0x04 to indicate an uncompressed point */
value = chunk_cata("cc", chunk_from_chars(0x04), value);
if (EVP_PKEY_copy_parameters(pub, this->key) <= 0 ||
EVP_PKEY_set1_tls_encodedpoint(pub, value.ptr, value.len) <= 0)
if (EVP_PKEY_copy_parameters(this->pub, this->key) <= 0 ||
EVP_PKEY_set1_tls_encodedpoint(this->pub, value.ptr, value.len) <= 0)
{
DBG1(DBG_LIB, "ECDH public value is malformed");
goto error;
return FALSE;
}
#endif
if (!openssl_compute_shared_key(this->key, pub, &this->shared_secret))
{
DBG1(DBG_LIB, "ECDH shared secret computation failed");
goto error;
}
this->computed = TRUE;
error:
EVP_PKEY_free(pub);
return this->computed;
chunk_clear(&this->shared_secret);
return TRUE;
}
METHOD(diffie_hellman_t, get_my_public_value, bool,
@@ -304,8 +294,10 @@ error:
METHOD(diffie_hellman_t, get_shared_secret, bool,
private_openssl_ec_diffie_hellman_t *this, chunk_t *secret)
{
if (!this->computed)
if (!this->shared_secret.len &&
!openssl_compute_shared_key(this->key, this->pub, &this->shared_secret))
{
DBG1(DBG_LIB, "ECDH shared secret computation failed");
return FALSE;
}
*secret = chunk_clone(this->shared_secret);
@@ -323,6 +315,7 @@ METHOD(diffie_hellman_t, destroy, void,
{
EC_GROUP_free(this->ec_group);
EVP_PKEY_free(this->key);
EVP_PKEY_free(this->pub);
chunk_clear(&this->shared_secret);
free(this);
}
src/libstrongswan/plugins/openssl/openssl_util.c
+1
View File
@@ -62,6 +62,7 @@ bool openssl_compute_shared_key(EVP_PKEY *priv, EVP_PKEY *pub, chunk_t *shared)
if (EVP_PKEY_derive(ctx, shared->ptr, &shared->len) <= 0)
{
chunk_clear(shared);
goto error;
}
src/libstrongswan/plugins/openssl/openssl_x_diffie_hellman.c
+14 -22
View File
@@ -45,15 +45,15 @@ struct private_diffie_hellman_t {
*/
EVP_PKEY *key;
/**
* Public key provided by peer
*/
EVP_PKEY *pub;
/**
* Shared secret
*/
chunk_t shared_secret;
/**
* True if shared secret is computed
*/
bool computed;
};
/**
@@ -75,33 +75,21 @@ static int map_key_type(diffie_hellman_group_t group)
METHOD(diffie_hellman_t, set_other_public_value, bool,
private_diffie_hellman_t *this, chunk_t value)
{
EVP_PKEY *pub;
if (!diffie_hellman_verify_value(this->group, value))
{
return FALSE;
}
pub = EVP_PKEY_new_raw_public_key(map_key_type(this->group), NULL,
value.ptr, value.len);
if (!pub)
EVP_PKEY_free(this->pub);
this->pub = EVP_PKEY_new_raw_public_key(map_key_type(this->group), NULL,
value.ptr, value.len);
if (!this->pub)
{
DBG1(DBG_LIB, "%N public value is malformed",
diffie_hellman_group_names, this->group);
return FALSE;
}
chunk_clear(&this->shared_secret);
if (!openssl_compute_shared_key(this->key, pub, &this->shared_secret))
{
DBG1(DBG_LIB, "%N shared secret computation failed",
diffie_hellman_group_names, this->group);
EVP_PKEY_free(pub);
return FALSE;
}
this->computed = TRUE;
EVP_PKEY_free(pub);
return TRUE;
}
@@ -141,8 +129,11 @@ METHOD(diffie_hellman_t, set_private_value, bool,
METHOD(diffie_hellman_t, get_shared_secret, bool,
private_diffie_hellman_t *this, chunk_t *secret)
{
if (!this->computed)
if (!this->shared_secret.len &&
!openssl_compute_shared_key(this->key, this->pub, &this->shared_secret))
{
DBG1(DBG_LIB, "%N shared secret computation failed",
diffie_hellman_group_names, this->group);
return FALSE;
}
*secret = chunk_clone(this->shared_secret);
@@ -159,6 +150,7 @@ METHOD(diffie_hellman_t, destroy, void,
private_diffie_hellman_t *this)
{
EVP_PKEY_free(this->key);
EVP_PKEY_free(this->pub);
chunk_clear(&this->shared_secret);
free(this);
}