5 EVP_RAND-HASH-DRBG - The HASH DRBG EVP_RAND implementation
9 Support for the hash deterministic random bit generator through the
14 "HASH-DRBG" is the name for this implementation; it can be used with the
15 EVP_RAND_fetch() function.
17 =head2 Supported parameters
19 The supported parameters are:
23 =item "state" (B<OSSL_RAND_PARAM_STATE>) <integer>
25 =item "strength" (B<OSSL_RAND_PARAM_STRENGTH>) <unsigned integer>
27 =item "reseed_requests" (B<OSSL_DRBG_PARAM_RESEED_REQUESTS>) <unsigned integer>
29 =item "reseed_time_interval" (B<OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL>) <integer>
31 =item "max_request" (B<OSSL_DRBG_PARAM_MAX_REQUEST>) <unsigned integer>
33 =item "min_entropylen" (B<OSSL_DRBG_PARAM_MIN_ENTROPYLEN>) <unsigned integer>
35 =item "max_entropylen" (B<OSSL_DRBG_PARAM_MAX_ENTROPYLEN>) <unsigned integer>
37 =item "min_noncelen" (B<OSSL_DRBG_PARAM_MIN_NONCELEN>) <unsigned integer>
39 =item "max_noncelen" (B<OSSL_DRBG_PARAM_MAX_NONCELEN>) <unsigned integer>
41 =item "max_perslen" (B<OSSL_DRBG_PARAM_MAX_PERSLEN>) <unsigned integer>
43 =item "max_adinlen" (B<OSSL_DRBG_PARAM_MAX_ADINLEN>) <unsigned integer>
45 =item "reseed_counter" (B<OSSL_DRBG_PARAM_RESEED_CTR>) <unsigned integer>
47 =item "properties" (B<OSSL_DRBG_PARAM_PROPERTIES>) <UTF8 string>
49 =item "digest" (B<OSSL_DRBG_PARAM_DIGEST>) <UTF8 string>
51 These parameters work as described in L<EVP_RAND(3)/PARAMETERS>.
57 A context for HASH DRBG can be obtained by calling:
59 EVP_RAND *rand = EVP_RAND_fetch(NULL, "HASH-DRBG", NULL);
60 EVP_RAND_CTX *rctx = EVP_RAND_CTX_new(rand);
66 unsigned char bytes[100];
67 OSSL_PARAM params[2], *p = params;
68 unsigned int strength = 128;
70 rand = EVP_RAND_fetch(NULL, "HASH-DRBG", NULL);
71 rctx = EVP_RAND_CTX_new(rand, NULL);
74 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_DIGEST, SN_sha512, 0);
75 *p = OSSL_PARAM_construct_end();
76 EVP_RAND_set_ctx_params(rctx, params);
78 EVP_RAND_generate(rctx, bytes, sizeof(bytes), strength, 0, NULL, 0);
80 EVP_RAND_CTX_free(rctx);
84 NIST SP 800-90A and SP 800-90B
89 L<EVP_RAND(3)/PARAMETERS>
93 Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
95 Licensed under the Apache License 2.0 (the "License"). You may not use
96 this file except in compliance with the License. You can obtain a copy
97 in the file LICENSE in the source distribution or at
98 L<https://www.openssl.org/source/license.html>.