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 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 <https://www.openssl.org/source/license.html>.