29f4b05954
resolve the Valgrind issue with random numbers. Undo the changes to RAND_bytes() and RAND_pseudo_bytes() that are redundant in this respect. Update documentation and FAQ accordingly, as the PURIFY macro is available at least since 0.9.7.
51 lines
1.5 KiB
Plaintext
51 lines
1.5 KiB
Plaintext
=pod
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=head1 NAME
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RAND_bytes, RAND_pseudo_bytes - generate random data
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=head1 SYNOPSIS
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#include <openssl/rand.h>
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int RAND_bytes(unsigned char *buf, int num);
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int RAND_pseudo_bytes(unsigned char *buf, int num);
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=head1 DESCRIPTION
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RAND_bytes() puts B<num> cryptographically strong pseudo-random bytes
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into B<buf>. An error occurs if the PRNG has not been seeded with
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enough randomness to ensure an unpredictable byte sequence.
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RAND_pseudo_bytes() puts B<num> pseudo-random bytes into B<buf>.
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Pseudo-random byte sequences generated by RAND_pseudo_bytes() will be
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unique if they are of sufficient length, but are not necessarily
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unpredictable. They can be used for non-cryptographic purposes and for
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certain purposes in cryptographic protocols, but usually not for key
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generation etc.
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The contents of B<buf> is mixed into the entropy pool before retrieving
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the new pseudo-random bytes unless disabled at compile time (see FAQ).
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=head1 RETURN VALUES
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RAND_bytes() returns 1 on success, 0 otherwise. The error code can be
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obtained by L<ERR_get_error(3)|ERR_get_error(3)>. RAND_pseudo_bytes() returns 1 if the
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bytes generated are cryptographically strong, 0 otherwise. Both
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functions return -1 if they are not supported by the current RAND
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method.
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=head1 SEE ALSO
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L<rand(3)|rand(3)>, L<ERR_get_error(3)|ERR_get_error(3)>,
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L<RAND_add(3)|RAND_add(3)>
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=head1 HISTORY
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RAND_bytes() is available in all versions of SSLeay and OpenSSL. It
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has a return value since OpenSSL 0.9.5. RAND_pseudo_bytes() was added
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in OpenSSL 0.9.5.
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=cut
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