/* * 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 2.1 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; g_autofree uint8_t *out = g_new(uint8_t, nout); uint64_t iterations = (1 << 15); unsigned long long delta_ms, start_ms, end_ms; 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); return ret; }