1 /* This Source Code Form is subject to the terms of the Mozilla Public
2  * License, v. 2.0. If a copy of the MPL was not distributed with this
3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4 
5 #ifndef _SECRNG_H_
6 #define _SECRNG_H_
7 /*
8  * secrng.h - public data structures and prototypes for the secure random
9  *	      number generator
10  */
11 
12 /******************************************/
13 /*
14 ** Random number generation. A cryptographically strong random number
15 ** generator.
16 */
17 
18 #include "blapi.h"
19 
20 /* the number of bytes to read from the system random number generator */
21 #define SYSTEM_RNG_SEED_COUNT 1024
22 
23 SEC_BEGIN_PROTOS
24 
25 /*
26 ** The following functions are provided by the security library
27 ** but are differently implemented for the UNIX, Win, and OS/2
28 ** versions
29 */
30 
31 /*
32 ** Get the "noisiest" information available on the system.
33 ** The amount of data returned depends on the system implementation.
34 ** It will not exceed maxbytes, but may be (much) less.
35 ** Returns number of noise bytes copied into buf, or zero if error.
36 */
37 extern size_t RNG_GetNoise(void *buf, size_t maxbytes);
38 
39 /*
40 ** RNG_SystemInfoForRNG should be called before any use of SSL. It
41 ** gathers up the system specific information to help seed the
42 ** state of the global random number generator.
43 */
44 extern void RNG_SystemInfoForRNG(void);
45 
46 /*
47 ** Use the contents (and stat) of a file to help seed the
48 ** global random number generator.
49 */
50 extern void RNG_FileForRNG(const char *filename);
51 
52 /*
53 ** Get maxbytes bytes of random data from the system random number
54 ** generator.
55 ** Returns the number of bytes copied into buf -- maxbytes if success
56 ** or zero if error.
57 ** Errors:
58 **   PR_NOT_IMPLEMENTED_ERROR   There is no system RNG on the platform.
59 **   SEC_ERROR_NEED_RANDOM      The system RNG failed.
60 */
61 extern size_t RNG_SystemRNG(void *buf, size_t maxbytes);
62 
63 SEC_END_PROTOS
64 
65 #endif /* _SECRNG_H_ */
66