NAME
CRYPTO_memcmp —
constant time memory
comparison
SYNOPSIS
#include
<openssl/crypto.h>
int
CRYPTO_memcmp(const void *a,
const void *b, size_t len);
DESCRIPTION
CRYPTO_memcmp()
compares the len bytes pointed to by
a and b for equality. It takes
an amount of time dependent on len, but independent of
the contents of the memory regions pointed to by a and
b.
RETURN VALUES
CRYPTO_memcmp() returns 0 if the content
of the memory regions is equal or non-zero otherwise.
HISTORY
CRYPTO_memcmp() first appeared in OpenSSL
1.0.1d and has been available since OpenBSD 5.6.
BUGS
Unlike memcmp(3) and timingsafe_memcmp(3), this function cannot be used to order the two memory regions. In the current implementation, the return value is always greater than or equal to 0.