RSA-PSS
Section: OpenSSL (7)
Updated: 2021-03-26
Page Index
NAME
RSA-PSS - EVP_PKEY RSA-PSS algorithm support
DESCRIPTION
The
RSA-PSS EVP_PKEY implementation is a restricted version of the
RSA
algorithm which only supports signing, verification and key generation
using
PSS padding modes with optional parameter restrictions.
It has associated private key and public key formats.
This algorithm shares several control operations with the RSA algorithm
but with some restrictions described below.
Signing and Verification
Signing and verification is similar to the
RSA algorithm except the
padding mode is always
PSS. If the key in use has parameter restrictions then
the corresponding signature parameters are set to the restrictions:
for example, if the key can only be used with digest
SHA256, MGF1 SHA256
and minimum salt length 32 then the digest,
MGF1 digest and salt length
will be set to
SHA256, SHA256 and 32 respectively.
Key Generation
By default no parameter restrictions are placed on the generated key.
NOTES
The public key format is documented in
RFC4055.
The PKCS#8 private key format used for RSA-PSS keys is similar to the RSA
format except it uses the id-RSASSA-PSS OID and the parameters field, if
present, restricts the key parameters in the same way as the public key.
CONFORMING TO
RFC 4055
SEE ALSO
EVP_PKEY_CTX_set_rsa_pss_keygen_md(3),
EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md(3),
EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen(3),
EVP_PKEY_CTX_new(3),
EVP_PKEY_CTX_ctrl_str(3),
EVP_PKEY_derive(3)
COPYRIGHT
Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (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
<https://www.openssl.org/source/license.html>.