1=pod 2 3=head1 NAME 4 5EVP_KDF-HMAC-DRBG 6- The HMAC DRBG DETERMINISTIC EVP_KDF implementation 7 8=head1 DESCRIPTION 9 10Support for a deterministic HMAC DRBG using the B<EVP_KDF> API. This is similar 11to L<EVP_RAND-HMAC-DRBG(7)>, but uses fixed values for its entropy and nonce 12values. This is used to generate deterministic nonce value required by ECDSA 13and DSA (as defined in RFC 6979). 14 15=head2 Identity 16 17"HMAC-DRBG-KDF" is the name for this implementation; it can be used 18with the EVP_KDF_fetch() function. 19 20=head2 Supported parameters 21 22The supported parameters are: 23 24=over 4 25 26=item "digest" (B<OSSL_DRBG_PARAM_DIGEST>) <UTF8 string> 27 28=item "properties" (B<OSSL_DRBG_PARAM_PROPERTIES>) <UTF8 string> 29 30These parameters work as described in L<EVP_KDF(3)/PARAMETERS>. 31 32=item "entropy" (B<OSSL_KDF_PARAM_HMACDRBG_ENTROPY>) <octet string> 33 34Sets the entropy bytes supplied to the HMAC-DRBG. 35 36=item "nonce" (B<OSSL_KDF_PARAM_HMACDRBG_NONCE>) <octet string> 37 38Sets the nonce bytes supplied to the HMAC-DRBG. 39 40=back 41 42=head1 NOTES 43 44A context for KDF HMAC DRBG can be obtained by calling: 45 46 EVP_KDF *kdf = EVP_KDF_fetch(NULL, "HMAC-DRBG-KDF", NULL); 47 EVP_KDF_CTX *kdf_ctx = EVP_KDF_CTX_new(kdf, NULL); 48 49=head1 CONFORMING TO 50 51RFC 6979 52 53=head1 SEE ALSO 54 55L<EVP_KDF(3)>, 56L<EVP_KDF(3)/PARAMETERS> 57 58=head1 HISTORY 59 60The EVP_KDF-HMAC-DRBG functionality was added in OpenSSL 3.2. 61 62=head1 COPYRIGHT 63 64Copyright 2022-2023 The OpenSSL Project Authors. All Rights Reserved. 65 66Licensed under the Apache License 2.0 (the "License"). You may not use 67this file except in compliance with the License. You can obtain a copy 68in the file LICENSE in the source distribution or at 69L<https://www.openssl.org/source/license.html>. 70 71=cut 72
