EXTERNAL_HEADERS/corecrypto/ccrng.h

   1 /*
   2  *  ccrng.h
   3  *  corecrypto
   4  *
   5  *  Created on 12/13/2010
   6  *
   7  *  Copyright (c) 2010,2011,2013,2014,2015 Apple Inc. All rights reserved.
   8  *
   9  */
  10
  11 #ifndef _CORECRYPTO_CCRNG_H_
  12 #define _CORECRYPTO_CCRNG_H_
  13
  14 #include <corecrypto/cc.h>
  15
  16 #define CCRNG_STATE_COMMON                                                          \
  17     int (*generate)(struct ccrng_state *rng, size_t outlen, void *out);
  18
  19 /* default state structure. Do not instantiate, ccrng() returns a reference to this structure */
  20 struct ccrng_state {
  21     CCRNG_STATE_COMMON
  22 };
  23
  24 /*!
  25  @function   ccrng
  26  @abstract   initializes a AES-CTR mode cryptographic random number generator and returns the statically alocated rng object.
  27              Getting a pointer to a ccrng has never been simpler!
  28              Call this function, get an rng object and then pass the object to ccrng_generate() to generate randoms.
  29              ccrng() may be called more than once. It returns pointer to the same object on all calls.
  30
  31  @result  a cryptographically secure random number generator or NULL if fails
  32
  33  @discussion
  34  - It is significantly faster than using the system /dev/random
  35  - FIPS Compliant: NIST SP800-80A + FIPS 140-2
  36  - Seeded from the system entropy.
  37  - Provides at least 128bit security if the system provide 2bit of entropy / byte.
  38  - Entropy accumulation
  39  - Backtracing resistance
  40  - Prediction break with frequent (asynchronous) reseed
  41  */
  42
  43 struct ccrng_state *ccrng(int *error);
  44
  45 //call this macro with the rng argument set to output of the call to the ccrng() function
  46 #define ccrng_generate(rng, outlen, out) ((rng)->generate((struct ccrng_state *)(rng), (outlen), (out)))
  47
  48 #endif /* _CORECRYPTO_CCRNG_H_ */