diff options
Diffstat (limited to 'ks_volatile.c')
-rw-r--r-- | ks_volatile.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/ks_volatile.c b/ks_volatile.c new file mode 100644 index 0000000..9a47d52 --- /dev/null +++ b/ks_volatile.c @@ -0,0 +1,143 @@ +/* + * ks_volatile.c + * ------------- + * Keystore implementation in normal volatile internal memory. + * + * NB: This is only suitable for cases where you do not want the keystore + * to survive library exit, eg, for storing PKCS #11 session keys. + * + * 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 "hal_internal.h" + +/* + * Splitting the different keystore backends out into separate files + * seemed like a good idea at the time, but the code is getting + * somewhat repetitive. Might want to re-merge and conditionalize in + * some other way. Deferred until we sort out ks_flash.c. + */ + +/* + * Use a one-element array here so that references can be pointer-based + * as in the other implementations, to ease re-merge at some later date. + */ + +static hal_ks_keydb_t db[1]; + +/* + * There's no good place to store the master key (KEK) in this volatile memory implementation. + * We might be able to add a bit of protection doing things like using locked physical memory, + * as gpg does, or obfuscating the KEK a bit to make it harder to pull out of a crash dump, + * but, really, there's not a lot we can do against a determined opponant in this case. + * + * For now, we just go through the motions. + */ + +static uint8_t kekbuf[bitsToBytes(256)]; + +const hal_ks_keydb_t *hal_ks_get_keydb(void) +{ + return db; +} + +hal_error_t hal_ks_set_keydb(const hal_ks_key_t * const key, + const int loc) +{ + if (key == NULL || loc < 0 || loc >= sizeof(db->keys)/sizeof(*db->keys) || key->in_use) + return HAL_ERROR_BAD_ARGUMENTS; + + db->keys[loc] = *key; + db->keys[loc].in_use = 1; + return HAL_OK; +} + +hal_error_t hal_ks_del_keydb(const int loc) +{ + if (loc < 0 || loc >= sizeof(db->keys)/sizeof(*db->keys)) + return HAL_ERROR_BAD_ARGUMENTS; + + memset(&db->keys[loc], 0, sizeof(db->keys[loc])); + return HAL_OK; +} + +hal_error_t hal_ks_set_pin(const hal_user_t user, + const hal_ks_pin_t * const pin) +{ + if (pin == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + hal_ks_pin_t *p = NULL; + + switch (user) { + case HAL_USER_WHEEL: p = &db->wheel_pin; break; + case HAL_USER_SO: p = &db->so_pin; break; + case HAL_USER_NORMAL: p = &db->user_pin; break; + default: return HAL_ERROR_BAD_ARGUMENTS; + } + + *p = *pin; + return HAL_OK; +} + +hal_error_t hal_ks_get_kek(uint8_t *kek, + size_t *kek_len, + const size_t kek_max) +{ + if (kek == NULL || kek_len == NULL || kek_max < bitsToBytes(128)) + return HAL_ERROR_BAD_ARGUMENTS; + + hal_error_t err; + + const size_t len = ((kek_max < bitsToBytes(192)) ? bitsToBytes(128) : + (kek_max < bitsToBytes(256)) ? bitsToBytes(192) : + bitsToBytes(256)); + + uint8_t t = 0; + + for (int i = 0; i < sizeof(kekbuf); i++) + t |= kekbuf[i]; + + if (t == 0 && (err = hal_rpc_get_random(kekbuf, sizeof(kekbuf))) != HAL_OK) + return err; + + memcpy(kek, kekbuf, len); + *kek_len = len; + return HAL_OK; +} + +/* + * Local variables: + * indent-tabs-mode: nil + * End: + */ |