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Diffstat (limited to 'rpc_misc.c')
| -rw-r--r-- | rpc_misc.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/rpc_misc.c b/rpc_misc.c new file mode 100644 index 0000000..bcd1974 --- /dev/null +++ b/rpc_misc.c @@ -0,0 +1,229 @@ +/* + * rpc_misc.c + * ---------- + * RPC interface to TRNG and PIN functions + * + * 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 <assert.h> + +#include "hal.h" +#include "hal_internal.h" + +static hal_error_t get_random(void *buffer, const size_t length) +{ + assert(buffer != NULL && length > 0); + + return hal_get_random(NULL, buffer, length); +} + +/* + * PINs, salt, and iteration count live in the keystore. + * + * We also need a client table in conventional memory (here, probably) + * to record login status. + * + * The USER and SO PINs correspond to PKCS #11. + * + * The WHEEL PIN is the one that's allowed to change the SO PIN. + * + * It's a bit unclear how we should manage changes to the WHEEL PIN. + * Implementing a factory default would be easy enough (just + * pre-compute and compile in a const hal_ks_pin_t), question is + * whether doing so provides anything useful. Certainly adds no real + * security, question is whether it would help prevent accidently + * bricking the HSM right out of the shrink wrap. + * + * More interesting question is whether we should ever allow the WHEEL + * PIN to be changed a second time without toasting the keystore. + */ + +#warning PIN code not yet fully implemented + +typedef struct { + hal_client_handle_t handle; + hal_user_t logged_in; +} client_slot_t; + +#ifndef HAL_PIN_MINIMUM_ITERATIONS +#define HAL_PIN_MINIMUM_ITERATIONS 10000 +#endif + +#ifndef HAL_PIN_DEFAULT_ITERATIONS +#define HAL_PIN_DEFAULT_ITERATIONS 20000 +#endif + +#ifndef HAL_STATIC_CLIENT_STATE_BLOCKS +#define HAL_STATIC_CLIENT_STATE_BLOCKS 10 +#endif + +#if HAL_STATIC_CLIENT_STATE_BLOCKS > 0 +static client_slot_t client_handle[HAL_STATIC_CLIENT_STATE_BLOCKS]; +#endif + +/* + * Client handles are supplied by the application, we don't get to + * pick them, we just store them and associate a login state with + * them. HAL_USER_NONE indicates an empty slot in the table. + */ + +static inline client_slot_t *alloc_slot(void) +{ +#if HAL_STATIC_CLIENT_STATE_BLOCKS > 0 + for (int i = 0; i < sizeof(client_handle)/sizeof(*client_handle); i++) + if (client_handle[i].logged_in == HAL_USER_NONE) + return &client_handle[i]; +#endif + + return NULL; +} + +static inline client_slot_t *find_handle(const hal_client_handle_t handle) +{ +#if HAL_STATIC_CLIENT_STATE_BLOCKS > 0 + for (int i = 0; i < sizeof(client_handle)/sizeof(*client_handle); i++) + if (client_handle[i].logged_in != HAL_USER_NONE && client_handle[i].handle.handle == handle.handle) + return &client_handle[i]; +#endif + + return NULL; +} + +static hal_error_t set_pin(const hal_client_handle_t client, + const hal_user_t user, + const char * const newpin, const size_t newpin_len) +{ + assert(newpin != NULL && newpin_len != 0); + +#warning Need access control to decide who is allowed to set this PIN +#warning Need length checks (here or in caller) on supplied PIN + + const hal_ks_pin_t *pp; + hal_error_t err; + + if ((err = hal_ks_get_pin(user, &pp)) != HAL_OK) + return err; + + hal_ks_pin_t p = *pp; + + if (p.iterations == 0) + p.iterations = HAL_PIN_DEFAULT_ITERATIONS; + + if ((err = hal_get_random(NULL, p.salt, sizeof(p.salt))) != HAL_OK || + (err = hal_pbkdf2(NULL, hal_hash_sha256, + (const uint8_t *) newpin, newpin_len, + p.salt, sizeof(p.salt), + p.pin, sizeof(p.pin), p.iterations)) != HAL_OK || + (err = hal_ks_set_pin(user, &p)) != HAL_OK) + return err; + + return HAL_OK; +} + +static hal_error_t login(const hal_client_handle_t client, + const hal_user_t user, + const char * const pin, const size_t pin_len) +{ + assert(pin != NULL && pin_len != 0); + assert(user == HAL_USER_NORMAL || user == HAL_USER_SO || user == HAL_USER_WHEEL); + + const hal_ks_pin_t *p; + hal_error_t err; + + if ((err = hal_ks_get_pin(user, &p)) != HAL_OK) + return err; + + uint8_t buf[sizeof(p->pin)]; + + if ((err = hal_pbkdf2(NULL, hal_hash_sha256, (const uint8_t *) pin, pin_len, + p->salt, sizeof(p->salt), buf, sizeof(buf), p->iterations)) != HAL_OK) + return err; + + unsigned diff = 0; + for (int i = 0; i < sizeof(buf); i++) + diff |= buf[i] ^ p->pin[i]; + + if (diff != 0) + return HAL_ERROR_PIN_INCORRECT; + + client_slot_t *slot = find_handle(client); + + if (slot == NULL && (slot = alloc_slot()) == NULL) + return HAL_ERROR_NO_CLIENT_SLOTS_AVAILABLE; + + slot->handle = client; + slot->logged_in = user; + + return HAL_OK; +} + +static hal_error_t is_logged_in(const hal_client_handle_t client, + const hal_user_t user) +{ + assert(user == HAL_USER_NORMAL || user == HAL_USER_SO || user == HAL_USER_WHEEL); + + client_slot_t *slot = find_handle(client); + + if (slot == NULL || slot->logged_in != user) + return HAL_ERROR_FORBIDDEN; + + return HAL_OK; +} + +static hal_error_t logout(const hal_client_handle_t client) +{ + client_slot_t *slot = find_handle(client); + + if (slot != NULL) + slot->logged_in = HAL_USER_NONE; + + return HAL_OK; +} + +static hal_error_t logout_all(void) +{ +#if HAL_STATIC_CLIENT_STATE_BLOCKS > 0 + for (int i = 0; i < sizeof(client_handle)/sizeof(*client_handle); i++) + client_handle[i].logged_in = HAL_USER_NONE; +#endif + + return HAL_OK; +} + +const hal_rpc_misc_dispatch_t hal_rpc_local_misc_dispatch = { + set_pin, login, logout, logout_all, is_logged_in, get_random +}; + +/* + * Local variables: + * indent-tabs-mode: nil + * End: + */ |