/*
* rpc_hash.c
* ----------
* Remote procedure call server-side hash implementation.
*
* Authors: Rob Austein
* Copyright (c) 2015, NORDUnet A/S All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of the NORDUnet nor the names of its contributors may
* be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <string.h>
#include "hal.h"
#include "rpc_internal.h"
/*
* Need table and handle allocation, including some kind of in_use
* flag (perhaps just handle == none).
*
* Hash and HMAC aren't really things for which we need permission
* bits, so not sure we even care about login stuff here.
*/
typedef struct {
hal_rpc_client_handle_t client_handle;
hal_rpc_session_handle_t session_handle;
hal_rpc_hash_handle_t hash_handle;
union {
hal_hash_state_t *hash;
hal_hmac_state_t *hmac;
} state;
} handle_slot_t;
#ifndef HAL_STATIC_HASH_STATE_BLOCKS
#define HAL_STATIC_HASH_STATE_BLOCKS 0
#endif
#ifndef HAL_STATIC_HMAC_STATE_BLOCKS
#define HAL_STATIC_HMAC_STATE_BLOCKS 0
#endif
#if HAL_STATIC_HASH_STATE_BLOCKS > 0
static handle_slot_t hash_handle[HAL_STATIC_HASH_STATE_BLOCKS];
#endif
#if HAL_STATIC_HMAC_STATE_BLOCKS > 0
static handle_slot_t hmac_handle[HAL_STATIC_HMAC_STATE_BLOCKS];
#endif
/*
* Handle allocation is simple: we look for an unused (state == NULL)
* slot in the appropriate table, and, assuming we find one, construct
* a composite handle consisting of a flag telling us which table this
* is, the index into the table, and a counter whose sole purpose is
* to keep the same handle from reoccurring anytime soon, to help
* identify use-after-free bugs in calling code.
*/
#define HANDLE_FLAG_HMAC 0x80000000
static inline handle_slot_t *alloc_handle(const int is_hmac)
{
#if HAL_STATIC_HASH_STATE_BLOCKS > 0 || HAL_STATIC_HMAC_STATE_BLOCKS > 0
static uint16_t next_glop = 0;
uint32_t glop = ++next_glop << 16;
next_glop %= 0x7FFF;
#endif
#if HAL_STATIC_HASH_STATE_BLOCKS > 0
if (!is_hmac) {
for (int i = 0; i < sizeof(hash_handle)/sizeof(*hash_handle); i++) {
if (hash_handle[i].state.hash == NULL) {
hash_handle[i].hash_handle.handle = i | glop;
return &hash_handle[i];
}
}
}
#endif
#if HAL_STATIC_HMAC_STATE_BLOCKS > 0
if (is_hmac) {
for (int i = 0; i < sizeof(hmac_handle)/sizeof(*hmac_handle); i++) {
if (hmac_handle[i].state.hmac == NULL) {
hmac_handle[i].hash_handle.handle = i | glop | HANDLE_FLAG_HMAC;
return &hmac_handle[i];
}
}
}
#endif
return NULL;
}
/*
* Check a caller-supplied handle. Must be in range, in use, and have
* the right glop. Returns slot pointer on success, NULL otherwise.
*/
static inline handle_slot_t *find_handle(const hal_rpc_hash_handle_t handle)
{
#if HAL_STATIC_HASH_STATE_BLOCKS > 0 || HAL_STATIC_HMAC_STATE_BLOCKS > 0
const int i = (int) (handle.handle & 0xFFFF);
const int is_hmac = (handle.handle & HANDLE_FLAG_HMAC) != 0;
#endif
#if HAL_STATIC_HASH_STATE_BLOCKS > 0
if (!is_hmac && i < sizeof(hash_handle)/sizeof(*hash_handle) &&
hash_handle[i].hash_handle.handle == handle.handle && hash_handle[i].state.hash != NULL)
return &hash_handle[i];
#endif
#if HAL_STATIC_HASH_STATE_BLOCKS > 0
if (is_hmac && i < sizeof(hmac_handle)/sizeof(*hmac_handle) &&
hmac_handle[i].hash_handle.handle == handle.handle && hmac_handle[i].state.hmac != NULL)
return &hmac_handle[i];
#endif
return NULL;
}
/*
* Translate an algorithm number to a descriptor.
*/
static inline const hal_hash_descriptor_t *alg_to_descriptor(const hal_digest_algorithm_t alg)
{
switch (alg) {
case hal_digest_algorithm_sha1: return hal_hash_sha1;
case hal_digest_algorithm_sha256: return hal_hash_sha256;
case hal_digest_algorithm_sha512_224: return hal_hash_sha512_224;
case hal_digest_algorithm_sha512_256: return hal_hash_sha512_256;
case hal_digest_algorithm_sha384: return hal_hash_sha384;
case hal_digest_algorithm_sha512: return hal_hash_sha512;
default: return NULL;
}
}
/*
* Given a slot pointer, fetch the descriptor.
*/
static inline const hal_hash_descriptor_t *slot_to_descriptor(const handle_slot_t * const slot)
{
if (slot == NULL)
return NULL;
if ((slot->hash_handle.handle & HANDLE_FLAG_HMAC) == 0)
return hal_hash_get_descriptor(slot->state.hash);
else
return hal_hmac_get_descriptor(slot->state.hmac);
}
/*
* Public API
*/
static hal_error_t get_digest_length(const hal_digest_algorithm_t alg, size_t *length)
{
const hal_hash_descriptor_t * const d = alg_to_descriptor(alg);
if (d == NULL || length == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
*length = d->digest_length;
return HAL_OK;
}
static hal_error_t get_digest_algorithm_id(const hal_digest_algorithm_t alg,
uint8_t *id, size_t *len, const size_t len_max)
{
const hal_hash_descriptor_t * const d = alg_to_descriptor(alg);
if (d == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
if (len != NULL)
*len = d->digest_algorithm_id_length;
if (id == NULL)
return HAL_OK;
if (len_max < d->digest_algorithm_id_length)
return HAL_ERROR_RESULT_TOO_LONG;
memcpy(id, d->digest_algorithm_id, d->digest_algorithm_id_length);
return HAL_OK;
}
static hal_error_t get_algorithm(const hal_rpc_hash_handle_t handle, hal_digest_algorithm_t *alg)
{
handle_slot_t *slot = find_handle(handle);
const hal_hash_descriptor_t *descriptor = slot_to_descriptor(slot);
if (slot == NULL || alg == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
if (descriptor == NULL)
return HAL_ERROR_IMPOSSIBLE;
*alg = descriptor->digest_algorithm;
return HAL_OK;
}
static hal_error_t initialize(const hal_rpc_client_handle_t client,
const hal_rpc_session_handle_t session,
hal_rpc_hash_handle_t *hash,
const hal_digest_algorithm_t alg,
const uint8_t * const key, const size_t key_len)
{
const hal_hash_descriptor_t *descriptor;
handle_slot_t *slot;
if (hash == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
if ((descriptor = alg_to_descriptor(alg)) == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
if ((slot = alloc_handle(key != NULL)) == NULL)
return HAL_ERROR_ALLOCATION_FAILURE;
slot->client_handle = client;
slot->session_handle = session;
if (key == NULL)
return hal_hash_initialize(NULL, descriptor, &slot->state.hash, NULL, 0);
else
return hal_hmac_initialize(NULL, descriptor, &slot->state.hmac, NULL, 0, key, key_len);
}
static hal_error_t update(const hal_rpc_hash_handle_t handle,
const uint8_t * data, const size_t length)
{
handle_slot_t *slot = find_handle(handle);
if (slot == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
if ((handle.handle & HANDLE_FLAG_HMAC) == 0)
return hal_hash_update(slot->state.hash, data, length);
else
return hal_hmac_update(slot->state.hmac, data, length);
}
static hal_error_t finalize(const hal_rpc_hash_handle_t handle,
uint8_t *digest, const size_t length)
{
handle_slot_t *slot = find_handle(handle);
hal_error_t err;
if (slot == NULL)
return HAL_ERROR_BAD_ARGUMENTS;
if ((handle.handle & HANDLE_FLAG_HMAC) == 0) {
err = hal_hash_finalize(slot->state.hash, digest, length);
hal_hash_cleanup(&slot->state.hash);
}
else {
err = hal_hmac_finalize(slot->state.hmac, digest, length);
hal_hmac_cleanup(&slot->state.hmac);
}
return err;
}
const hal_rpc_hash_dispatch_t hal_rpc_remote_hash_dispatch = {
get_digest_length, get_digest_algorithm_id, get_algorithm, initialize, update, finalize
};
/*
* Local variables:
* indent-tabs-mode: nil
* End:
*/
