RAND_bytes.pod

=pod

=head1 NAME

RAND_bytes, RAND_pseudo_bytes - Generate random data

=head1 SYNOPSIS

 #include <openssl/rand.h>

 int RAND_bytes(unsigned char *buf, int num);

 int RAND_pseudo_bytes(unsigned char *buf, int num);

=head1 DESCRIPTION

RAND_bytes() puts B<num> random bytes into B<buf>. An error occurs if
the PRNG has not been seeded with enough randomness.

RAND_pseudo_bytes() puts B<num> pseudo-random bytes into B<buf>. These
bytes are guaranteed to be unique, but not unpredictable. They can be
used for non-cryptographic purposes and for certain purposes in
cryptographic protocols, but not for key generation etc.

=head1 RETURN VALUES

RAND_bytes() returns 1 on success, 0 otherwise. The error code can be
obtained by ERR_get_error(3). RAND_pseudo_bytes() returns 1 if the
bytes generated are cryptographically strong, 0 otherwise. Both
functions return -1 if they are not supported by the current RAND
method.

=head1 SEE ALSO

rand(3), err(3), RAND_add(3)

=head1 HISTORY

RAND_bytes() is available in all versions of SSLeay and OpenSSL.  It
has a return value since OpenSSL 0.9.5. RAND_pseudo_bytes() was added
in OpenSSL 0.9.5.

=cut