114 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			114 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
 | |
|  * QEMU Crypto PBKDF support (Password-Based Key Derivation Function)
 | |
|  *
 | |
|  * Copyright (c) 2015-2016 Red Hat, Inc.
 | |
|  *
 | |
|  * This library is free software; you can redistribute it and/or
 | |
|  * modify it under the terms of the GNU Lesser General Public
 | |
|  * License as published by the Free Software Foundation; either
 | |
|  * version 2 of the License, or (at your option) any later version.
 | |
|  *
 | |
|  * This library is distributed in the hope that it will be useful,
 | |
|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 | |
|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 | |
|  * Lesser General Public License for more details.
 | |
|  *
 | |
|  * You should have received a copy of the GNU Lesser General Public
 | |
|  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 | |
|  *
 | |
|  */
 | |
| 
 | |
| #include "qemu/osdep.h"
 | |
| #include "qapi/error.h"
 | |
| #include "crypto/pbkdf.h"
 | |
| #ifndef _WIN32
 | |
| #include <sys/resource.h>
 | |
| #endif
 | |
| 
 | |
| 
 | |
| static int qcrypto_pbkdf2_get_thread_cpu(unsigned long long *val_ms,
 | |
|                                          Error **errp)
 | |
| {
 | |
| #ifdef _WIN32
 | |
|     FILETIME creation_time, exit_time, kernel_time, user_time;
 | |
|     ULARGE_INTEGER thread_time;
 | |
| 
 | |
|     if (!GetThreadTimes(GetCurrentThread(), &creation_time, &exit_time,
 | |
|                         &kernel_time, &user_time)) {
 | |
|         error_setg(errp, "Unable to get thread CPU usage");
 | |
|         return -1;
 | |
|     }
 | |
| 
 | |
|     thread_time.LowPart = user_time.dwLowDateTime;
 | |
|     thread_time.HighPart = user_time.dwHighDateTime;
 | |
| 
 | |
|     /* QuadPart is units of 100ns and we want ms as unit */
 | |
|     *val_ms = thread_time.QuadPart / 10000ll;
 | |
|     return 0;
 | |
| #elif defined(RUSAGE_THREAD)
 | |
|     struct rusage ru;
 | |
|     if (getrusage(RUSAGE_THREAD, &ru) < 0) {
 | |
|         error_setg_errno(errp, errno, "Unable to get thread CPU usage");
 | |
|         return -1;
 | |
|     }
 | |
| 
 | |
|     *val_ms = ((ru.ru_utime.tv_sec * 1000ll) +
 | |
|                (ru.ru_utime.tv_usec / 1000));
 | |
|     return 0;
 | |
| #else
 | |
|     *val_ms = 0;
 | |
|     error_setg(errp, "Unable to calculate thread CPU usage on this platform");
 | |
|     return -1;
 | |
| #endif
 | |
| }
 | |
| 
 | |
| uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash,
 | |
|                                     const uint8_t *key, size_t nkey,
 | |
|                                     const uint8_t *salt, size_t nsalt,
 | |
|                                     size_t nout,
 | |
|                                     Error **errp)
 | |
| {
 | |
|     uint64_t ret = -1;
 | |
|     uint8_t *out;
 | |
|     uint64_t iterations = (1 << 15);
 | |
|     unsigned long long delta_ms, start_ms, end_ms;
 | |
| 
 | |
|     out = g_new(uint8_t, nout);
 | |
| 
 | |
|     while (1) {
 | |
|         if (qcrypto_pbkdf2_get_thread_cpu(&start_ms, errp) < 0) {
 | |
|             goto cleanup;
 | |
|         }
 | |
|         if (qcrypto_pbkdf2(hash,
 | |
|                            key, nkey,
 | |
|                            salt, nsalt,
 | |
|                            iterations,
 | |
|                            out, nout,
 | |
|                            errp) < 0) {
 | |
|             goto cleanup;
 | |
|         }
 | |
|         if (qcrypto_pbkdf2_get_thread_cpu(&end_ms, errp) < 0) {
 | |
|             goto cleanup;
 | |
|         }
 | |
| 
 | |
|         delta_ms = end_ms - start_ms;
 | |
| 
 | |
|         if (delta_ms > 500) {
 | |
|             break;
 | |
|         } else if (delta_ms < 100) {
 | |
|             iterations = iterations * 10;
 | |
|         } else {
 | |
|             iterations = (iterations * 1000 / delta_ms);
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     iterations = iterations * 1000 / delta_ms;
 | |
| 
 | |
|     ret = iterations;
 | |
| 
 | |
|  cleanup:
 | |
|     memset(out, 0, nout);
 | |
|     g_free(out);
 | |
|     return ret;
 | |
| }
 |