Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20210330' into...
[qemu/ar7.git] / crypto / pbkdf.c
blob3775ddc6c5a2c50d744023e50e16b4eb87def975
1 /*
2  * QEMU Crypto PBKDF support (Password-Based Key Derivation Function)
3  *
4  * Copyright (c) 2015-2016 Red Hat, Inc.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  *
19  */
21 #include "qemu/osdep.h"
22 #include "qapi/error.h"
23 #include "crypto/pbkdf.h"
24 #ifndef _WIN32
25 #include <sys/resource.h>
26 #endif
29 static int qcrypto_pbkdf2_get_thread_cpu(unsigned long long *val_ms,
30                                          Error **errp)
32 #ifdef _WIN32
33     FILETIME creation_time, exit_time, kernel_time, user_time;
34     ULARGE_INTEGER thread_time;
36     if (!GetThreadTimes(GetCurrentThread(), &creation_time, &exit_time,
37                         &kernel_time, &user_time)) {
38         error_setg(errp, "Unable to get thread CPU usage");
39         return -1;
40     }
42     thread_time.LowPart = user_time.dwLowDateTime;
43     thread_time.HighPart = user_time.dwHighDateTime;
45     /* QuadPart is units of 100ns and we want ms as unit */
46     *val_ms = thread_time.QuadPart / 10000ll;
47     return 0;
48 #elif defined(RUSAGE_THREAD)
49     struct rusage ru;
50     if (getrusage(RUSAGE_THREAD, &ru) < 0) {
51         error_setg_errno(errp, errno, "Unable to get thread CPU usage");
52         return -1;
53     }
55     *val_ms = ((ru.ru_utime.tv_sec * 1000ll) +
56                (ru.ru_utime.tv_usec / 1000));
57     return 0;
58 #else
59     *val_ms = 0;
60     error_setg(errp, "Unable to calculate thread CPU usage on this platform");
61     return -1;
62 #endif
65 uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash,
66                                     const uint8_t *key, size_t nkey,
67                                     const uint8_t *salt, size_t nsalt,
68                                     size_t nout,
69                                     Error **errp)
71     uint64_t ret = -1;
72     g_autofree uint8_t *out = g_new(uint8_t, nout);
73     uint64_t iterations = (1 << 15);
74     unsigned long long delta_ms, start_ms, end_ms;
76     while (1) {
77         if (qcrypto_pbkdf2_get_thread_cpu(&start_ms, errp) < 0) {
78             goto cleanup;
79         }
80         if (qcrypto_pbkdf2(hash,
81                            key, nkey,
82                            salt, nsalt,
83                            iterations,
84                            out, nout,
85                            errp) < 0) {
86             goto cleanup;
87         }
88         if (qcrypto_pbkdf2_get_thread_cpu(&end_ms, errp) < 0) {
89             goto cleanup;
90         }
92         delta_ms = end_ms - start_ms;
94         if (delta_ms > 500) {
95             break;
96         } else if (delta_ms < 100) {
97             iterations = iterations * 10;
98         } else {
99             iterations = (iterations * 1000 / delta_ms);
100         }
101     }
103     iterations = iterations * 1000 / delta_ms;
105     ret = iterations;
107  cleanup:
108     memset(out, 0, nout);
109     return ret;