| 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 | */ |
| 20 | |
| 21 | #include "qemu/osdep.h" |
| 22 | #include "qemu/thread.h" |
| 23 | #include "qapi/error.h" |
| 24 | #include "crypto/pbkdf.h" |
| 25 | #ifndef _WIN32 |
| 26 | #include <sys/resource.h> |
| 27 | #endif |
| 28 | #ifdef CONFIG_DARWIN |
| 29 | #include <mach/mach_init.h> |
| 30 | #include <mach/thread_act.h> |
| 31 | #include <mach/mach_port.h> |
| 32 | #endif |
| 33 | |
| 34 | |
| 35 | static int qcrypto_pbkdf2_get_thread_cpu(unsigned long long *val_ms, |
| 36 | Error **errp) |
| 37 | { |
| 38 | #ifdef _WIN32 |
| 39 | FILETIME creation_time, exit_time, kernel_time, user_time; |
| 40 | ULARGE_INTEGER thread_time; |
| 41 | |
| 42 | if (!GetThreadTimes(GetCurrentThread(), &creation_time, &exit_time, |
| 43 | &kernel_time, &user_time)) { |
| 44 | error_setg(errp, "Unable to get thread CPU usage"); |
| 45 | return -1; |
| 46 | } |
| 47 | |
| 48 | thread_time.LowPart = user_time.dwLowDateTime; |
| 49 | thread_time.HighPart = user_time.dwHighDateTime; |
| 50 | |
| 51 | /* QuadPart is units of 100ns and we want ms as unit */ |
| 52 | *val_ms = thread_time.QuadPart / 10000ll; |
| 53 | return 0; |
| 54 | #elif defined(CONFIG_DARWIN) |
| 55 | mach_port_t thread; |
| 56 | kern_return_t kr; |
| 57 | mach_msg_type_number_t count; |
| 58 | thread_basic_info_data_t info; |
| 59 | |
| 60 | thread = mach_thread_self(); |
| 61 | count = THREAD_BASIC_INFO_COUNT; |
| 62 | kr = thread_info(thread, THREAD_BASIC_INFO, (thread_info_t)&info, &count); |
| 63 | mach_port_deallocate(mach_task_self(), thread); |
| 64 | if (kr != KERN_SUCCESS || (info.flags & TH_FLAGS_IDLE) != 0) { |
| 65 | error_setg_errno(errp, errno, "Unable to get thread CPU usage"); |
| 66 | return -1; |
| 67 | } |
| 68 | |
| 69 | *val_ms = ((info.user_time.seconds * 1000ll) + |
| 70 | (info.user_time.microseconds / 1000)); |
| 71 | return 0; |
| 72 | #elif defined(RUSAGE_THREAD) |
| 73 | struct rusage ru; |
| 74 | if (getrusage(RUSAGE_THREAD, &ru) < 0) { |
| 75 | error_setg_errno(errp, errno, "Unable to get thread CPU usage"); |
| 76 | return -1; |
| 77 | } |
| 78 | |
| 79 | *val_ms = ((ru.ru_utime.tv_sec * 1000ll) + |
| 80 | (ru.ru_utime.tv_usec / 1000)); |
| 81 | return 0; |
| 82 | #else |
| 83 | *val_ms = 0; |
| 84 | error_setg(errp, "Unable to calculate thread CPU usage on this platform"); |
| 85 | return -1; |
| 86 | #endif |
| 87 | } |
| 88 | |
| 89 | typedef struct CountItersData { |
| 90 | QCryptoHashAlgo hash; |
| 91 | const uint8_t *key; |
| 92 | size_t nkey; |
| 93 | const uint8_t *salt; |
| 94 | size_t nsalt; |
| 95 | size_t nout; |
| 96 | uint64_t iterations; |
| 97 | Error **errp; |
| 98 | } CountItersData; |
| 99 | |
| 100 | static void *threaded_qcrypto_pbkdf2_count_iters(void *data) |
| 101 | { |
| 102 | CountItersData *iters_data = (CountItersData *) data; |
| 103 | QCryptoHashAlgo hash = iters_data->hash; |
| 104 | const uint8_t *key = iters_data->key; |
| 105 | size_t nkey = iters_data->nkey; |
| 106 | const uint8_t *salt = iters_data->salt; |
| 107 | size_t nsalt = iters_data->nsalt; |
| 108 | size_t nout = iters_data->nout; |
| 109 | Error **errp = iters_data->errp; |
| 110 | size_t scaled = 0; |
| 111 | uint64_t ret = -1; |
| 112 | g_autofree uint8_t *out = g_new(uint8_t, nout); |
| 113 | uint64_t iterations = (1 << 15); |
| 114 | unsigned long long delta_ms, start_ms, end_ms; |
| 115 | |
| 116 | while (1) { |
| 117 | if (qcrypto_pbkdf2_get_thread_cpu(&start_ms, errp) < 0) { |
| 118 | goto cleanup; |
| 119 | } |
| 120 | if (qcrypto_pbkdf2(hash, |
| 121 | key, nkey, |
| 122 | salt, nsalt, |
| 123 | iterations, |
| 124 | out, nout, |
| 125 | errp) < 0) { |
| 126 | goto cleanup; |
| 127 | } |
| 128 | if (qcrypto_pbkdf2_get_thread_cpu(&end_ms, errp) < 0) { |
| 129 | goto cleanup; |
| 130 | } |
| 131 | |
| 132 | delta_ms = end_ms - start_ms; |
| 133 | |
| 134 | /* |
| 135 | * For very small 'iterations' values, CPU (or crypto |
| 136 | * accelerator) might be fast enough that the scheduler |
| 137 | * hasn't incremented getrusage() data, or incremented |
| 138 | * it by a very small amount, resulting in delta_ms == 0. |
| 139 | * Once we've scaled 'iterations' x10, 5 times, we really |
| 140 | * should be seeing delta_ms != 0, so sanity check at |
| 141 | * that point. |
| 142 | */ |
| 143 | if (scaled > 5 && |
| 144 | delta_ms == 0) { /* sanity check */ |
| 145 | error_setg(errp, "Unable to get accurate CPU usage"); |
| 146 | goto cleanup; |
| 147 | } else if (delta_ms > 500) { |
| 148 | break; |
| 149 | } else if (delta_ms < 100) { |
| 150 | iterations = iterations * 10; |
| 151 | } else { |
| 152 | iterations = (iterations * 1000 / delta_ms); |
| 153 | } |
| 154 | scaled++; |
| 155 | } |
| 156 | |
| 157 | iterations = iterations * 1000 / delta_ms; |
| 158 | |
| 159 | ret = iterations; |
| 160 | |
| 161 | cleanup: |
| 162 | memset(out, 0, nout); |
| 163 | iters_data->iterations = ret; |
| 164 | return NULL; |
| 165 | } |
| 166 | |
| 167 | uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgo hash, |
| 168 | const uint8_t *key, size_t nkey, |
| 169 | const uint8_t *salt, size_t nsalt, |
| 170 | size_t nout, |
| 171 | Error **errp) |
| 172 | { |
| 173 | CountItersData data = { |
| 174 | hash, key, nkey, salt, nsalt, nout, 0, errp |
| 175 | }; |
| 176 | QemuThread thread; |
| 177 | |
| 178 | qemu_thread_create(&thread, "pbkdf2", threaded_qcrypto_pbkdf2_count_iters, |
| 179 | &data, QEMU_THREAD_JOINABLE); |
| 180 | qemu_thread_join(&thread); |
| 181 | |
| 182 | return data.iterations; |
| 183 | } |