2019-06-24 07:18:48 +08:00
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=pod
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=head1 NAME
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CRYPTO_memcmp - Constant time memory comparison
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=head1 SYNOPSIS
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#include <openssl/crypto.h>
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int CRYPTO_memcmp(const void *a, const void *b, size_t len);
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=head1 DESCRIPTION
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The CRYPTO_memcmp function compares the B<len> bytes pointed to by B<a> and B<b>
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for equality.
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It takes an amount of time dependent on B<len>, but independent of the
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contents of the memory regions pointed to by B<a> and B<b>.
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=head1 RETURN VALUES
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2019-09-28 01:17:09 +08:00
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CRYPTO_memcmp() returns 0 if the memory regions are equal and nonzero
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2019-06-24 07:18:48 +08:00
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otherwise.
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=head1 NOTES
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Unlike memcmp(2), this function cannot be used to order the two memory regions
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2019-09-28 01:17:09 +08:00
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as the return value when they differ is undefined, other than being nonzero.
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2019-06-24 07:18:48 +08:00
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=head1 COPYRIGHT
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Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
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Licensed under the Apache License 2.0 (the "License"). You may not use
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this file except in compliance with the License. You can obtain a copy
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in the file LICENSE in the source distribution or at
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L<https://www.openssl.org/source/license.html>.
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=cut
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