1=pod 2 3=head1 NAME 4 5EVP_PKEY_CTX_set_rsa_pss_keygen_md, 6EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md, 7EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen 8- EVP_PKEY RSA-PSS algorithm support functions 9 10=head1 SYNOPSIS 11 12 #include <openssl/rsa.h> 13 14 int EVP_PKEY_CTX_set_rsa_pss_keygen_md(EVP_PKEY_CTX *pctx, 15 const EVP_MD *md); 16 int EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md(EVP_PKEY_CTX *pctx, 17 const EVP_MD *md); 18 int EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen(EVP_PKEY_CTX *pctx, 19 int saltlen); 20 21=head1 DESCRIPTION 22 23These are the functions that implement L<RSA-PSS(7)>. 24 25=head2 Signing and Verification 26 27The macro EVP_PKEY_CTX_set_rsa_padding() is supported but an error is 28returned if an attempt is made to set the padding mode to anything other 29than B<PSS>. It is otherwise similar to the B<RSA> version. 30 31The EVP_PKEY_CTX_set_rsa_pss_saltlen() macro is used to set the salt length. 32If the key has usage restrictions then an error is returned if an attempt is 33made to set the salt length below the minimum value. It is otherwise similar 34to the B<RSA> operation except detection of the salt length (using 35RSA_PSS_SALTLEN_AUTO) is not supported for verification if the key has 36usage restrictions. 37 38The EVP_PKEY_CTX_set_signature_md() and EVP_PKEY_CTX_set_rsa_mgf1_md() macros 39are used to set the digest and MGF1 algorithms respectively. If the key has 40usage restrictions then an error is returned if an attempt is made to set the 41digest to anything other than the restricted value. Otherwise these are 42similar to the B<RSA> versions. 43 44=head2 Key Generation 45 46As with RSA key generation the EVP_PKEY_CTX_set_rsa_keygen_bits() 47and EVP_PKEY_CTX_set_rsa_keygen_pubexp() macros are supported for RSA-PSS: 48they have exactly the same meaning as for the RSA algorithm. 49 50Optional parameter restrictions can be specified when generating a PSS key. 51If any restrictions are set (using the macros described below) then B<all> 52parameters are restricted. For example, setting a minimum salt length also 53restricts the digest and MGF1 algorithms. If any restrictions are in place 54then they are reflected in the corresponding parameters of the public key 55when (for example) a certificate request is signed. 56 57EVP_PKEY_CTX_set_rsa_pss_keygen_md() restricts the digest algorithm the 58generated key can use to B<md>. 59 60EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md() restricts the MGF1 algorithm the 61generated key can use to B<md>. 62 63EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen() restricts the minimum salt length 64to B<saltlen>. 65 66=head1 NOTES 67 68A context for the B<RSA-PSS> algorithm can be obtained by calling: 69 70 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA_PSS, NULL); 71 72=head1 RETURN VALUES 73 74All these functions return 1 for success and 0 or a negative value for failure. 75In particular a return value of -2 indicates the operation is not supported by 76the public key algorithm. 77 78=head1 SEE ALSO 79 80L<RSA-PSS(7)>, 81L<EVP_PKEY_CTX_new(3)>, 82L<EVP_PKEY_CTX_ctrl_str(3)>, 83L<EVP_PKEY_derive(3)> 84 85=head1 COPYRIGHT 86 87Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved. 88 89Licensed under the OpenSSL license (the "License"). You may not use 90this file except in compliance with the License. You can obtain a copy 91in the file LICENSE in the source distribution or at 92L<https://www.openssl.org/source/license.html>. 93 94=cut 95