tor-android/external/badvpn_dns/security/OTPGenerator.c

160 lines
4.3 KiB
C

/**
* @file OTPGenerator.c
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the author 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 AUTHOR 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 <security/OTPGenerator.h>
static void work_func (OTPGenerator *g)
{
g->otps[!g->cur_calc] = OTPCalculator_Generate(&g->calc[!g->cur_calc], g->tw_key, g->tw_iv, 1);
}
static void work_done_handler (OTPGenerator *g)
{
ASSERT(g->tw_have)
DebugObject_Access(&g->d_obj);
// free work
BThreadWork_Free(&g->tw);
g->tw_have = 0;
// use new OTPs
g->cur_calc = !g->cur_calc;
g->position = 0;
// call handler
g->handler(g->user);
return;
}
int OTPGenerator_Init (OTPGenerator *g, int num_otps, int cipher, BThreadWorkDispatcher *twd, OTPGenerator_handler handler, void *user)
{
ASSERT(num_otps >= 0)
ASSERT(BEncryption_cipher_valid(cipher))
// init arguments
g->num_otps = num_otps;
g->cipher = cipher;
g->twd = twd;
g->handler = handler;
g->user = user;
// init position
g->position = g->num_otps;
// init calculator
if (!OTPCalculator_Init(&g->calc[0], g->num_otps, g->cipher)) {
goto fail0;
}
// init calculator
if (!OTPCalculator_Init(&g->calc[1], g->num_otps, g->cipher)) {
goto fail1;
}
// set current calculator
g->cur_calc = 0;
// have no work
g->tw_have = 0;
DebugObject_Init(&g->d_obj);
return 1;
fail1:
OTPCalculator_Free(&g->calc[0]);
fail0:
return 0;
}
void OTPGenerator_Free (OTPGenerator *g)
{
DebugObject_Free(&g->d_obj);
// free work
if (g->tw_have) {
BThreadWork_Free(&g->tw);
}
// free calculator
OTPCalculator_Free(&g->calc[1]);
// free calculator
OTPCalculator_Free(&g->calc[0]);
}
void OTPGenerator_SetSeed (OTPGenerator *g, uint8_t *key, uint8_t *iv)
{
DebugObject_Access(&g->d_obj);
// free existing work
if (g->tw_have) {
BThreadWork_Free(&g->tw);
}
// copy key and IV
memcpy(g->tw_key, key, BEncryption_cipher_key_size(g->cipher));
memcpy(g->tw_iv, iv, BEncryption_cipher_block_size(g->cipher));
// start work
BThreadWork_Init(&g->tw, g->twd, (BThreadWork_handler_done)work_done_handler, g, (BThreadWork_work_func)work_func, g);
// set have work
g->tw_have = 1;
}
int OTPGenerator_GetPosition (OTPGenerator *g)
{
DebugObject_Access(&g->d_obj);
return g->position;
}
void OTPGenerator_Reset (OTPGenerator *g)
{
DebugObject_Access(&g->d_obj);
// free existing work
if (g->tw_have) {
BThreadWork_Free(&g->tw);
g->tw_have = 0;
}
g->position = g->num_otps;
}
otp_t OTPGenerator_GetOTP (OTPGenerator *g)
{
ASSERT(g->position < g->num_otps)
DebugObject_Access(&g->d_obj);
return g->otps[g->cur_calc][g->position++];
}