Simplify cleanup paths by using glib's auto cleanup macros for stack variables, allowing several goto jumps / labels to be eliminated. Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
		
			
				
	
	
		
			111 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			111 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * QEMU Crypto PBKDF support (Password-Based Key Derivation Function)
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 *
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 * Copyright (c) 2015-2016 Red Hat, Inc.
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
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 *
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 */
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#include "qemu/osdep.h"
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#include "qapi/error.h"
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#include "crypto/pbkdf.h"
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#ifndef _WIN32
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#include <sys/resource.h>
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#endif
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static int qcrypto_pbkdf2_get_thread_cpu(unsigned long long *val_ms,
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                                         Error **errp)
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{
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#ifdef _WIN32
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    FILETIME creation_time, exit_time, kernel_time, user_time;
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    ULARGE_INTEGER thread_time;
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    if (!GetThreadTimes(GetCurrentThread(), &creation_time, &exit_time,
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                        &kernel_time, &user_time)) {
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        error_setg(errp, "Unable to get thread CPU usage");
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        return -1;
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    }
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    thread_time.LowPart = user_time.dwLowDateTime;
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    thread_time.HighPart = user_time.dwHighDateTime;
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    /* QuadPart is units of 100ns and we want ms as unit */
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    *val_ms = thread_time.QuadPart / 10000ll;
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    return 0;
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#elif defined(RUSAGE_THREAD)
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    struct rusage ru;
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    if (getrusage(RUSAGE_THREAD, &ru) < 0) {
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        error_setg_errno(errp, errno, "Unable to get thread CPU usage");
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        return -1;
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    }
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    *val_ms = ((ru.ru_utime.tv_sec * 1000ll) +
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               (ru.ru_utime.tv_usec / 1000));
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    return 0;
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#else
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    *val_ms = 0;
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    error_setg(errp, "Unable to calculate thread CPU usage on this platform");
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    return -1;
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#endif
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}
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uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash,
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                                    const uint8_t *key, size_t nkey,
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                                    const uint8_t *salt, size_t nsalt,
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                                    size_t nout,
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                                    Error **errp)
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{
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    uint64_t ret = -1;
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    g_autofree uint8_t *out = g_new(uint8_t, nout);
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    uint64_t iterations = (1 << 15);
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    unsigned long long delta_ms, start_ms, end_ms;
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    while (1) {
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        if (qcrypto_pbkdf2_get_thread_cpu(&start_ms, errp) < 0) {
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            goto cleanup;
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        }
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        if (qcrypto_pbkdf2(hash,
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                           key, nkey,
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                           salt, nsalt,
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                           iterations,
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                           out, nout,
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                           errp) < 0) {
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            goto cleanup;
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        }
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        if (qcrypto_pbkdf2_get_thread_cpu(&end_ms, errp) < 0) {
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            goto cleanup;
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        }
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        delta_ms = end_ms - start_ms;
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        if (delta_ms > 500) {
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            break;
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        } else if (delta_ms < 100) {
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            iterations = iterations * 10;
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        } else {
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            iterations = (iterations * 1000 / delta_ms);
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        }
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    }
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    iterations = iterations * 1000 / delta_ms;
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    ret = iterations;
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 cleanup:
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    memset(out, 0, nout);
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    return ret;
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}
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