262 lines
5.7 KiB
C
262 lines
5.7 KiB
C
/*
|
|
* Copyright (C) 2018 René Korthaus
|
|
* Copyright (C) 2018 Konstantinos Kolelis
|
|
* Rohde & Schwarz Cybersecurity GmbH
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include "botan_diffie_hellman.h"
|
|
|
|
#include <botan/build.h>
|
|
|
|
#ifdef BOTAN_HAS_DIFFIE_HELLMAN
|
|
|
|
#include "botan_util.h"
|
|
|
|
#include <botan/ffi.h>
|
|
|
|
#include <utils/debug.h>
|
|
|
|
typedef struct private_botan_diffie_hellman_t private_botan_diffie_hellman_t;
|
|
|
|
/**
|
|
* Private data of an botan_diffie_hellman_t object.
|
|
*/
|
|
struct private_botan_diffie_hellman_t {
|
|
|
|
/**
|
|
* Public botan_diffie_hellman_t interface
|
|
*/
|
|
botan_diffie_hellman_t public;
|
|
|
|
/**
|
|
* Diffie Hellman group number
|
|
*/
|
|
diffie_hellman_group_t group;
|
|
|
|
/**
|
|
* Private key
|
|
*/
|
|
botan_privkey_t dh_key;
|
|
|
|
/**
|
|
* Diffie hellman shared secret
|
|
*/
|
|
chunk_t shared_secret;
|
|
|
|
/**
|
|
* Generator value
|
|
*/
|
|
botan_mp_t g;
|
|
|
|
/**
|
|
* Modulus
|
|
*/
|
|
botan_mp_t p;
|
|
|
|
};
|
|
|
|
bool load_private_key(private_botan_diffie_hellman_t *this, chunk_t value)
|
|
{
|
|
botan_mp_t xa;
|
|
if (chunk_to_botan_mp(value, &xa))
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
if (botan_privkey_destroy(this->dh_key) ||
|
|
botan_privkey_load_dh (&this->dh_key, this->p, this->g, xa))
|
|
{
|
|
return FALSE;
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
METHOD(diffie_hellman_t, set_other_public_value, bool,
|
|
private_botan_diffie_hellman_t *this, chunk_t value)
|
|
{
|
|
botan_pk_op_ka_t op;
|
|
|
|
if (!diffie_hellman_verify_value(this->group, value))
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
chunk_clear(&this->shared_secret);
|
|
botan_pk_op_key_agreement_create(&op, this->dh_key, "Raw", 0);
|
|
|
|
/* get shared secret key size */
|
|
if (botan_pk_op_key_agreement(op, NULL, &this->shared_secret.len, value.ptr,
|
|
value.len, NULL, 0)
|
|
!= BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
this->shared_secret = chunk_alloc(this->shared_secret.len);
|
|
if (botan_pk_op_key_agreement(op, this->shared_secret.ptr,
|
|
&this->shared_secret.len, value.ptr,
|
|
value.len, NULL, 0))
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
METHOD(diffie_hellman_t, get_my_public_value, bool,
|
|
private_botan_diffie_hellman_t *this, chunk_t *value)
|
|
{
|
|
*value = chunk_empty;
|
|
|
|
/* get key size of public key first */
|
|
if (botan_pk_op_key_agreement_export_public(this->dh_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,
|
|
&value->len))
|
|
{
|
|
chunk_clear(value);
|
|
return FALSE;
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
METHOD(diffie_hellman_t, set_private_value, bool,
|
|
private_botan_diffie_hellman_t *this, chunk_t value)
|
|
{
|
|
return load_private_key(this, value);
|
|
}
|
|
|
|
METHOD(diffie_hellman_t, get_shared_secret, bool,
|
|
private_botan_diffie_hellman_t *this, chunk_t *secret)
|
|
{
|
|
if (this->shared_secret.len == 0)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
*secret = chunk_clone(this->shared_secret);
|
|
return TRUE;
|
|
}
|
|
|
|
METHOD(diffie_hellman_t, get_dh_group, diffie_hellman_group_t,
|
|
private_botan_diffie_hellman_t *this)
|
|
{
|
|
return this->group;
|
|
}
|
|
|
|
METHOD(diffie_hellman_t, destroy, void,
|
|
private_botan_diffie_hellman_t *this)
|
|
{
|
|
botan_mp_destroy(this->p);
|
|
botan_mp_destroy(this->g);
|
|
botan_privkey_destroy(this->dh_key);
|
|
chunk_clear(&this->shared_secret);
|
|
free(this);
|
|
}
|
|
|
|
/*
|
|
* Generic internal constructor
|
|
*/
|
|
botan_diffie_hellman_t *create_generic(diffie_hellman_group_t group,
|
|
chunk_t g, chunk_t p)
|
|
{
|
|
private_botan_diffie_hellman_t *this;
|
|
|
|
INIT(this,
|
|
.public = {
|
|
.dh = {
|
|
.get_shared_secret = _get_shared_secret,
|
|
.set_other_public_value = _set_other_public_value,
|
|
.get_my_public_value = _get_my_public_value,
|
|
.set_private_value = _set_private_value,
|
|
.get_dh_group = _get_dh_group,
|
|
.destroy = _destroy,
|
|
},
|
|
},
|
|
.group = group,
|
|
);
|
|
|
|
if (chunk_to_botan_mp(p, &this->p))
|
|
{
|
|
destroy(this);
|
|
return NULL;
|
|
}
|
|
|
|
if (chunk_to_botan_mp(g, &this->g))
|
|
{
|
|
destroy(this);
|
|
return NULL;
|
|
}
|
|
|
|
chunk_t random;
|
|
rng_t *rng;
|
|
rng = lib->crypto->create_rng(lib->crypto, RNG_STRONG);
|
|
if (rng && rng->allocate_bytes(rng, p.len, &random))
|
|
{
|
|
rng->destroy(rng);
|
|
if (!load_private_key(this, random))
|
|
{
|
|
destroy(this);
|
|
chunk_clear(&random);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
return &this->public;
|
|
}
|
|
|
|
/*
|
|
* Described in header.
|
|
*/
|
|
botan_diffie_hellman_t *
|
|
botan_diffie_hellman_create(diffie_hellman_group_t group)
|
|
{
|
|
diffie_hellman_params_t *params;
|
|
params = diffie_hellman_get_params(group);
|
|
if (!params)
|
|
{
|
|
return NULL;
|
|
}
|
|
return create_generic(group, params->generator, params->prime);
|
|
}
|
|
|
|
/*
|
|
* Described in header.
|
|
*/
|
|
botan_diffie_hellman_t *
|
|
botan_diffie_hellman_create_custom(diffie_hellman_group_t group, chunk_t g,
|
|
chunk_t p)
|
|
{
|
|
if (group == MODP_CUSTOM)
|
|
{
|
|
return create_generic(group, g, p);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
#endif
|