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-rw-r--r--lib/crypto_backend/pbkdf_check.c431
1 files changed, 431 insertions, 0 deletions
diff --git a/lib/crypto_backend/pbkdf_check.c b/lib/crypto_backend/pbkdf_check.c
new file mode 100644
index 0000000..db65eab
--- /dev/null
+++ b/lib/crypto_backend/pbkdf_check.c
@@ -0,0 +1,431 @@
+/*
+ * PBKDF performance check
+ * Copyright (C) 2012-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2012-2019 Milan Broz
+ * Copyright (C) 2016-2019 Ondrej Mosnacek
+ *
+ * This file 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 file 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 file; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <limits.h>
+#include <time.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include "crypto_backend.h"
+
+#define BENCH_MIN_MS 250
+#define BENCH_MIN_MS_FAST 10
+#define BENCH_PERCENT_ATLEAST 95
+#define BENCH_PERCENT_ATMOST 110
+#define BENCH_SAMPLES_FAST 3
+#define BENCH_SAMPLES_SLOW 1
+
+/* These PBKDF2 limits must be never violated */
+int crypt_pbkdf_get_limits(const char *kdf, struct crypt_pbkdf_limits *limits)
+{
+ if (!kdf || !limits)
+ return -EINVAL;
+
+ if (!strcmp(kdf, "pbkdf2")) {
+ limits->min_iterations = 1000; /* recommendation in NIST SP 800-132 */
+ limits->max_iterations = UINT32_MAX;
+ limits->min_memory = 0; /* N/A */
+ limits->max_memory = 0; /* N/A */
+ limits->min_parallel = 0; /* N/A */
+ limits->max_parallel = 0; /* N/A */
+ return 0;
+ } else if (!strcmp(kdf, "argon2i") || !strcmp(kdf, "argon2id")) {
+ limits->min_iterations = 4;
+ limits->max_iterations = UINT32_MAX;
+ limits->min_memory = 32;
+ limits->max_memory = 4*1024*1024; /* 4GiB */
+ limits->min_parallel = 1;
+ limits->max_parallel = 4;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static long time_ms(struct rusage *start, struct rusage *end)
+{
+ int count_kernel_time = 0;
+ long ms;
+
+ if (crypt_backend_flags() & CRYPT_BACKEND_KERNEL)
+ count_kernel_time = 1;
+
+ /*
+ * FIXME: if there is no self usage info, count system time.
+ * This seem like getrusage() bug in some hypervisors...
+ */
+ if (!end->ru_utime.tv_sec && !start->ru_utime.tv_sec &&
+ !end->ru_utime.tv_usec && !start->ru_utime.tv_usec)
+ count_kernel_time = 1;
+
+ ms = (end->ru_utime.tv_sec - start->ru_utime.tv_sec) * 1000;
+ ms += (end->ru_utime.tv_usec - start->ru_utime.tv_usec) / 1000;
+
+ if (count_kernel_time) {
+ ms += (end->ru_stime.tv_sec - start->ru_stime.tv_sec) * 1000;
+ ms += (end->ru_stime.tv_usec - start->ru_stime.tv_usec) / 1000;
+ }
+
+ return ms;
+}
+
+static long timespec_ms(struct timespec *start, struct timespec *end)
+{
+ return (end->tv_sec - start->tv_sec) * 1000 +
+ (end->tv_nsec - start->tv_nsec) / (1000 * 1000);
+}
+
+static int measure_argon2(const char *kdf, const char *password, size_t password_length,
+ const char *salt, size_t salt_length,
+ char *key, size_t key_length,
+ uint32_t t_cost, uint32_t m_cost, uint32_t parallel,
+ size_t samples, long ms_atleast, long *out_ms)
+{
+ long ms, ms_min = LONG_MAX;
+ int r;
+ size_t i;
+
+ for (i = 0; i < samples; i++) {
+ struct timespec tstart, tend;
+
+ /*
+ * NOTE: We must use clock_gettime here, because Argon2 can run over
+ * multiple threads, and thus we care about real time, not CPU time!
+ */
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &tstart) < 0)
+ return -EINVAL;
+
+ r = crypt_pbkdf(kdf, NULL, password, password_length, salt,
+ salt_length, key, key_length, t_cost, m_cost, parallel);
+ if (r < 0)
+ return r;
+
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &tend) < 0)
+ return -EINVAL;
+
+ ms = timespec_ms(&tstart, &tend);
+ if (ms < 0)
+ return -EINVAL;
+
+ if (ms < ms_atleast) {
+ /* early exit */
+ ms_min = ms;
+ break;
+ }
+ if (ms < ms_min) {
+ ms_min = ms;
+ }
+ }
+ *out_ms = ms_min;
+ return 0;
+}
+
+#define CONTINUE 0
+#define FINAL 1
+static int next_argon2_params(uint32_t *t_cost, uint32_t *m_cost,
+ uint32_t min_t_cost, uint32_t min_m_cost,
+ uint32_t max_m_cost, long ms, uint32_t target_ms)
+{
+ uint32_t old_t_cost, old_m_cost, new_t_cost, new_m_cost;
+ uint64_t num, denom;
+
+ old_t_cost = *t_cost;
+ old_m_cost = *m_cost;
+
+ if (ms > target_ms) {
+ /* decreasing, first try to lower t_cost, then m_cost */
+ num = (uint64_t)*t_cost * (uint64_t)target_ms;
+ denom = (uint64_t)ms;
+ new_t_cost = (uint32_t)(num / denom);
+ if (new_t_cost < min_t_cost) {
+ num = (uint64_t)*t_cost * (uint64_t)*m_cost *
+ (uint64_t)target_ms;
+ denom = (uint64_t)min_t_cost * (uint64_t)ms;
+ *t_cost = min_t_cost;
+ *m_cost = (uint32_t)(num / denom);
+ if (*m_cost < min_m_cost) {
+ *m_cost = min_m_cost;
+ return FINAL;
+ }
+ } else {
+ *t_cost = new_t_cost;
+ }
+ } else {
+ /* increasing, first try to increase m_cost, then t_cost */
+ num = (uint64_t)*m_cost * (uint64_t)target_ms;
+ denom = (uint64_t)ms;
+ new_m_cost = (uint32_t)(num / denom);
+ if (new_m_cost > max_m_cost) {
+ num = (uint64_t)*t_cost * (uint64_t)*m_cost *
+ (uint64_t)target_ms;
+ denom = (uint64_t)max_m_cost * (uint64_t)ms;
+ *t_cost = (uint32_t)(num / denom);
+ *m_cost = max_m_cost;
+ if (*t_cost <= min_t_cost) {
+ *t_cost = min_t_cost;
+ return FINAL;
+ }
+ } else if (new_m_cost < min_m_cost) {
+ *m_cost = min_m_cost;
+ return FINAL;
+ } else {
+ *m_cost = new_m_cost;
+ }
+ }
+
+ /* do not continue if it is the same as in the previous run */
+ if (old_t_cost == *t_cost && old_m_cost == *m_cost)
+ return FINAL;
+
+ return CONTINUE;
+}
+
+static int crypt_argon2_check(const char *kdf, const char *password,
+ size_t password_length, const char *salt,
+ size_t salt_length, size_t key_length,
+ uint32_t min_t_cost, uint32_t min_m_cost, uint32_t max_m_cost,
+ uint32_t parallel, uint32_t target_ms,
+ uint32_t *out_t_cost, uint32_t *out_m_cost,
+ int (*progress)(uint32_t time_ms, void *usrptr),
+ void *usrptr)
+{
+ int r = 0;
+ char *key = NULL;
+ uint32_t t_cost, m_cost;
+ long ms;
+ long ms_atleast = (long)target_ms * BENCH_PERCENT_ATLEAST / 100;
+ long ms_atmost = (long)target_ms * BENCH_PERCENT_ATMOST / 100;
+
+ if (key_length <= 0 || target_ms <= 0)
+ return -EINVAL;
+
+ if (min_m_cost < (parallel * 8))
+ min_m_cost = parallel * 8;
+
+ if (max_m_cost < min_m_cost)
+ return -EINVAL;
+
+ key = malloc(key_length);
+ if (!key)
+ return -ENOMEM;
+
+ t_cost = min_t_cost;
+ m_cost = min_m_cost;
+
+ /* 1. Find some small parameters, s. t. ms >= BENCH_MIN_MS: */
+ while (1) {
+ r = measure_argon2(kdf, password, password_length, salt, salt_length,
+ key, key_length, t_cost, m_cost, parallel,
+ BENCH_SAMPLES_FAST, BENCH_MIN_MS, &ms);
+ if (!r) {
+ /* Update parameters to actual measurement */
+ *out_t_cost = t_cost;
+ *out_m_cost = m_cost;
+ if (progress && progress((uint32_t)ms, usrptr))
+ r = -EINTR;
+ }
+
+ if (r < 0)
+ goto out;
+
+ if (ms >= BENCH_MIN_MS)
+ break;
+
+ if (m_cost == max_m_cost) {
+ if (ms < BENCH_MIN_MS_FAST)
+ t_cost *= 16;
+ else {
+ uint32_t new = (t_cost * BENCH_MIN_MS) / (uint32_t)ms;
+ if (new == t_cost)
+ break;
+
+ t_cost = new;
+ }
+ } else {
+ if (ms < BENCH_MIN_MS_FAST)
+ m_cost *= 16;
+ else {
+ uint32_t new = (m_cost * BENCH_MIN_MS) / (uint32_t)ms;
+ if (new == m_cost)
+ break;
+
+ m_cost = new;
+ }
+ if (m_cost > max_m_cost) {
+ m_cost = max_m_cost;
+ }
+ }
+ }
+ /*
+ * 2. Use the params obtained in (1.) to estimate the target params.
+ * 3. Then repeatedly measure the candidate params and if they fall out of
+ * the acceptance range (+-5 %), try to improve the estimate:
+ */
+ do {
+ if (next_argon2_params(&t_cost, &m_cost, min_t_cost, min_m_cost,
+ max_m_cost, ms, target_ms)) {
+ /* Update parameters to final computation */
+ *out_t_cost = t_cost;
+ *out_m_cost = m_cost;
+ break;
+ }
+
+ r = measure_argon2(kdf, password, password_length, salt, salt_length,
+ key, key_length, t_cost, m_cost, parallel,
+ BENCH_SAMPLES_SLOW, ms_atleast, &ms);
+
+ if (!r) {
+ /* Update parameters to actual measurement */
+ *out_t_cost = t_cost;
+ *out_m_cost = m_cost;
+ if (progress && progress((uint32_t)ms, usrptr))
+ r = -EINTR;
+ }
+
+ if (r < 0)
+ break;
+
+ } while (ms < ms_atleast || ms > ms_atmost);
+out:
+ if (key) {
+ crypt_backend_memzero(key, key_length);
+ free(key);
+ }
+ return r;
+}
+
+/* This code benchmarks PBKDF and returns iterations/second using specified hash */
+static int crypt_pbkdf_check(const char *kdf, const char *hash,
+ const char *password, size_t password_length,
+ const char *salt, size_t salt_length,
+ size_t key_length, uint32_t *iter_secs, uint32_t target_ms,
+ int (*progress)(uint32_t time_ms, void *usrptr), void *usrptr)
+
+{
+ struct rusage rstart, rend;
+ int r = 0, step = 0;
+ long ms = 0;
+ char *key = NULL;
+ uint32_t iterations;
+ double PBKDF2_temp;
+
+ if (!kdf || !hash || key_length <= 0)
+ return -EINVAL;
+
+ key = malloc(key_length);
+ if (!key)
+ return -ENOMEM;
+
+ *iter_secs = 0;
+ iterations = 1 << 15;
+ while (1) {
+ if (getrusage(RUSAGE_SELF, &rstart) < 0) {
+ r = -EINVAL;
+ goto out;
+ }
+
+ r = crypt_pbkdf(kdf, hash, password, password_length, salt,
+ salt_length, key, key_length, iterations, 0, 0);
+
+ if (r < 0)
+ goto out;
+
+ if (getrusage(RUSAGE_SELF, &rend) < 0) {
+ r = -EINVAL;
+ goto out;
+ }
+
+ ms = time_ms(&rstart, &rend);
+ if (ms) {
+ PBKDF2_temp = (double)iterations * target_ms / ms;
+ if (PBKDF2_temp > UINT32_MAX)
+ return -EINVAL;
+ *iter_secs = (uint32_t)PBKDF2_temp;
+ }
+
+ if (progress && progress((uint32_t)ms, usrptr)) {
+ r = -EINTR;
+ goto out;
+ }
+
+ if (ms > 500)
+ break;
+
+ if (ms <= 62)
+ iterations <<= 4;
+ else if (ms <= 125)
+ iterations <<= 3;
+ else if (ms <= 250)
+ iterations <<= 2;
+ else
+ iterations <<= 1;
+
+ if (++step > 10 || !iterations) {
+ r = -EINVAL;
+ goto out;
+ }
+ }
+out:
+ if (key) {
+ crypt_backend_memzero(key, key_length);
+ free(key);
+ }
+ return r;
+}
+
+int crypt_pbkdf_perf(const char *kdf, const char *hash,
+ const char *password, size_t password_size,
+ const char *salt, size_t salt_size,
+ size_t volume_key_size, uint32_t time_ms,
+ uint32_t max_memory_kb, uint32_t parallel_threads,
+ uint32_t *iterations_out, uint32_t *memory_out,
+ int (*progress)(uint32_t time_ms, void *usrptr), void *usrptr)
+{
+ struct crypt_pbkdf_limits pbkdf_limits;
+ int r = -EINVAL;
+
+ if (!kdf || !iterations_out || !memory_out)
+ return -EINVAL;
+
+ /* FIXME: whole limits propagation should be more clear here */
+ r = crypt_pbkdf_get_limits(kdf, &pbkdf_limits);
+ if (r < 0)
+ return r;
+
+ *memory_out = 0;
+ *iterations_out = 0;
+
+ if (!strcmp(kdf, "pbkdf2"))
+ r = crypt_pbkdf_check(kdf, hash, password, password_size,
+ salt, salt_size, volume_key_size,
+ iterations_out, time_ms, progress, usrptr);
+
+ else if (!strncmp(kdf, "argon2", 6))
+ r = crypt_argon2_check(kdf, password, password_size,
+ salt, salt_size, volume_key_size,
+ pbkdf_limits.min_iterations,
+ pbkdf_limits.min_memory,
+ max_memory_kb,
+ parallel_threads, time_ms, iterations_out,
+ memory_out, progress, usrptr);
+ return r;
+}
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