man > RSA-PSS(7SSL)

man perldoc info pydoc3 ri search

📛 NAME

RSA-PSS - EVP_PKEY RSA-PSS algorithm support

🚀 Quick Reference

Use Case	Command	Description
🔑 Generate key (default)	openssl genpkey -algorithm RSA-PSS -out key.pem	Create an RSA-PSS private key with no parameter restrictions
🔑 Generate key with restrictions	openssl genpkey -algorithm RSA-PSS -out key.pem -pkeyopt rsa_keygen_bits:2048 -pkeyopt rsa_pss_keygen_md:sha256 -pkeyopt rsa_pss_keygen_mgf1_md:sha256 -pkeyopt rsa_pss_keygen_saltlen:32	Key locked to SHA‑256, MGF1 SHA‑256, salt length 32
🖋️ Sign a file	openssl dgst -sha256 -sign key.pem -sigopt rsa_padding_mode:pss -out sig.bin data.txt	Create a PSS signature; digest and salt length auto‑match key restrictions if present
🔍 Verify a signature	openssl dgst -sha256 -verify public.pem -sigopt rsa_padding_mode:pss -signature sig.bin data.txt	Verify PSS signature using the public key
📊 Inspect key parameters	openssl pkey -in key.pem -text -noout	Display PSS restrictions (digest, MGF1 digest, salt length)

📖 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>.

📛 NAME 🚀 Quick Reference 📖 DESCRIPTION 📝 NOTES ✅ CONFORMING TO 🔗 SEE ALSO © COPYRIGHT