mirror of
https://github.com/openssl/openssl.git
synced 2024-12-27 06:21:43 +08:00
8020d79b40
Reviewed-by: Richard Levitte <levitte@openssl.org> (Merged from https://github.com/openssl/openssl/pull/14512)
88 lines
2.2 KiB
Plaintext
88 lines
2.2 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
EVP_RAND-SEED-SRC - The randomness seed source EVP_RAND implementation
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
Support for deterministic random number generator seeding through the
|
|
B<EVP_RAND> API.
|
|
|
|
The seed sources used are specified at the time OpenSSL is configured for
|
|
building using the B<--with-rand-seed=> option. By default, operating system
|
|
randomness sources are used.
|
|
|
|
=head2 Identity
|
|
|
|
"SEED-SRC" is the name for this implementation; it can be used with the
|
|
EVP_RAND_fetch() function.
|
|
|
|
=head2 Supported parameters
|
|
|
|
The supported parameters are:
|
|
|
|
=over 4
|
|
|
|
=item "state" (B<OSSL_RAND_PARAM_STATE>) <integer>
|
|
|
|
=item "strength" (B<OSSL_RAND_PARAM_STRENGTH>) <unsigned integer>
|
|
|
|
=item "max_request" (B<OSSL_RAND_PARAM_MAX_REQUEST>) <unsigned integer>
|
|
|
|
These parameters work as described in L<EVP_RAND(3)/PARAMETERS>.
|
|
|
|
=back
|
|
|
|
=head1 NOTES
|
|
|
|
A context for the seed source can be obtained by calling:
|
|
|
|
EVP_RAND *rand = EVP_RAND_fetch(NULL, "SEED-SRC", NULL);
|
|
EVP_RAND_CTX *rctx = EVP_RAND_CTX_new(rand);
|
|
|
|
=head1 EXAMPLES
|
|
|
|
EVP_RAND *rand;
|
|
EVP_RAND_CTX *seed, *rctx;
|
|
unsigned char bytes[100];
|
|
OSSL_PARAM params[2], *p = params;
|
|
unsigned int strength = 128;
|
|
|
|
/* Create a seed source */
|
|
rand = EVP_RAND_fetch(NULL, "SEED-SRC", NULL);
|
|
seed = EVP_RAND_CTX_new(rand, NULL);
|
|
EVP_RAND_free(rand);
|
|
|
|
/* Feed this into a DRBG */
|
|
rand = EVP_RAND_fetch(NULL, "CTR-DRBG", NULL);
|
|
rctx = EVP_RAND_CTX_new(rand, seed);
|
|
EVP_RAND_free(rand);
|
|
|
|
/* Configure the DRBG */
|
|
*p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER,
|
|
SN_aes_256_ctr, 0);
|
|
*p = OSSL_PARAM_construct_end();
|
|
EVP_RAND_instantiate(rctx, strength, 0, NULL, 0, params);
|
|
|
|
EVP_RAND_generate(rctx, bytes, sizeof(bytes), strength, 0, NULL, 0);
|
|
|
|
EVP_RAND_CTX_free(rctx);
|
|
EVP_RAND_CTX_free(seed);
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<EVP_RAND(3)>,
|
|
L<EVP_RAND(3)/PARAMETERS>
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2020-2021 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the Apache License 2.0 (the "License"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file LICENSE in the source distribution or at
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|