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RAND_bytes(3)
NAME
  RAND_bytes, RAND_pseudo_bytes - Generate random data

SYNOPSIS
  #include <openssl/rand.h>

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

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

DESCRIPTION
  The RAND_bytes() function puts num cryptographically strong pseudo-random
  bytes into buf.  An error occurs if the PRNG has not been seeded with
  enough randomness to ensure an unpredictable byte sequence.

  The RAND_pseudo_bytes() function puts num pseudo-random bytes into buf.
  Pseudo-random byte sequences generated by the RAND_pseudo_bytes() function
  will be unique if they are of sufficient length, but are not necessarily
  unpredictable.  They can be used for non-cryptographic purposes and for
  certain purposes in cryptographic protocols, but usually not for key
  generation etc.

RETURN VALUES
  The RAND_bytes() functon returns 1 on success, 0 otherwise. The error code
  can be obtained by using ERR_get_error(). The RAND_pseudo_bytes() function
  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.

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

SEE ALSO
  Functions: rand_ssl(3), err(3), RAND_add(3)

Index for Section 3

Alphabetical listing for R

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