1 /*
2 * Copyright 2011-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <openssl/evp.h>
11 #include <openssl/rand.h>
12 #include "rand_local.h"
13
14 /* Implements the default OpenSSL RAND_add() method */
drbg_add(const void * buf,int num,double randomness)15 static int drbg_add(const void *buf, int num, double randomness)
16 {
17 EVP_RAND_CTX *drbg = RAND_get0_primary(NULL);
18
19 if (drbg == NULL || num <= 0)
20 return 0;
21
22 return EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
23 }
24
25 /* Implements the default OpenSSL RAND_seed() method */
drbg_seed(const void * buf,int num)26 static int drbg_seed(const void *buf, int num)
27 {
28 return drbg_add(buf, num, num);
29 }
30
31 /* Implements the default OpenSSL RAND_status() method */
drbg_status(void)32 static int drbg_status(void)
33 {
34 EVP_RAND_CTX *drbg = RAND_get0_primary(NULL);
35
36 if (drbg == NULL)
37 return 0;
38
39 return EVP_RAND_get_state(drbg) == EVP_RAND_STATE_READY ? 1 : 0;
40 }
41
42 /* Implements the default OpenSSL RAND_bytes() method */
drbg_bytes(unsigned char * out,int count)43 static int drbg_bytes(unsigned char *out, int count)
44 {
45 EVP_RAND_CTX *drbg = RAND_get0_public(NULL);
46
47 if (drbg == NULL)
48 return 0;
49
50 return EVP_RAND_generate(drbg, out, count, 0, 0, NULL, 0);
51 }
52
53 RAND_METHOD ossl_rand_meth = {
54 drbg_seed,
55 drbg_bytes,
56 NULL,
57 drbg_add,
58 drbg_bytes,
59 drbg_status
60 };
61
RAND_OpenSSL(void)62 RAND_METHOD *RAND_OpenSSL(void)
63 {
64 return &ossl_rand_meth;
65 }
66