diff options
Diffstat (limited to 'rpc_hash.c')
| -rw-r--r-- | rpc_hash.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/rpc_hash.c b/rpc_hash.c new file mode 100644 index 0000000..1bce86e --- /dev/null +++ b/rpc_hash.c @@ -0,0 +1,312 @@ +/* + * rpc_hash.c + * ---------- + * Remote procedure call server-side hash implementation. + * + * Authors: Rob Austein + * Copyright (c) 2015-2016, 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 "hal_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_client_handle_t client_handle; + hal_session_handle_t session_handle; + hal_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) + continue; + 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) + continue; + 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_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_HMAC_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; +} + +static inline free_handle(handle_slot_t *slot) +{ + /* state is a union, so this this works for hash and hmac */ + slot->state.hash = 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_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_client_handle_t client, + const hal_session_handle_t session, + hal_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; + hal_error_t err; + + 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_len != 0)) == NULL) + return HAL_ERROR_ALLOCATION_FAILURE; + + slot->client_handle = client; + slot->session_handle = session; + *hash = slot->hash_handle; + + if (key_len == 0) + err = hal_hash_initialize(NULL, descriptor, &slot->state.hash, NULL, 0); + else + err = hal_hmac_initialize(NULL, descriptor, &slot->state.hmac, NULL, 0, key, key_len); + if (err != HAL_OK) + free_handle(slot); + return err; +} + +static hal_error_t update(const hal_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_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); + } + + free_handle(slot); + return err; +} + +const hal_rpc_hash_dispatch_t hal_rpc_local_hash_dispatch = { + get_digest_length, get_digest_algorithm_id, get_algorithm, initialize, update, finalize +}; + +/* + * Local variables: + * indent-tabs-mode: nil + * End: + */ |