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authorDon Dugger <n0ano@n0ano.com>2016-06-03 03:33:22 +0000
committerGerrit Code Review <gerrit@172.30.200.206>2016-06-03 03:33:23 +0000
commitda27230f80795d0028333713f036d44c53cb0e68 (patch)
treeb3d379eaf000adf72b36cb01cdf4d79c3e3f064c /qemu/crypto/pbkdf.c
parent0e68cb048bb8aadb14675f5d4286d8ab2fc35449 (diff)
parent437fd90c0250dee670290f9b714253671a990160 (diff)
Merge "These changes are the raw update to qemu-2.6."
Diffstat (limited to 'qemu/crypto/pbkdf.c')
-rw-r--r--qemu/crypto/pbkdf.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/qemu/crypto/pbkdf.c b/qemu/crypto/pbkdf.c
new file mode 100644
index 000000000..695cc35df
--- /dev/null
+++ b/qemu/crypto/pbkdf.c
@@ -0,0 +1,110 @@
+/*
+ * 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
+}
+
+int qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash,
+ const uint8_t *key, size_t nkey,
+ const uint8_t *salt, size_t nsalt,
+ Error **errp)
+{
+ uint8_t out[32];
+ long long int iterations = (1 << 15);
+ unsigned long long delta_ms, start_ms, end_ms;
+
+ while (1) {
+ if (qcrypto_pbkdf2_get_thread_cpu(&start_ms, errp) < 0) {
+ return -1;
+ }
+ if (qcrypto_pbkdf2(hash,
+ key, nkey,
+ salt, nsalt,
+ iterations,
+ out, sizeof(out),
+ errp) < 0) {
+ return -1;
+ }
+ if (qcrypto_pbkdf2_get_thread_cpu(&end_ms, errp) < 0) {
+ return -1;
+ }
+
+ 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;
+
+ if (iterations > INT32_MAX) {
+ error_setg(errp, "Iterations %lld too large for a 32-bit int",
+ iterations);
+ return -1;
+ }
+
+ return iterations;
+}