EVP_KEM-RSA(7ssl)

EVP_KEM-RSA7ssl

Evp_kem rsa keytype and algorithm support

Overview

The RSA keytype and its parameters are described in EVP_PKEY-RSA(7). See EVP_PKEY_encapsulate(3) and EVP_PKEY_decapsulate(3) for more info.

RSA KEM parameters

"operation" (OSSL_KEM_PARAM_OPERATION) <UTF8 string>

The OpenSSL RSA Key Encapsulation Mechanism only currently supports the following default operation (operating mode):

"RSASVE"

The encapsulate function simply generates a secret using random bytes and then encrypts the secret using the RSA public key (with no padding). The decapsulate function recovers the secret using the RSA private key.

This can be set using EVP_PKEY_CTX_set_kem_op().

"fips-indicator" (OSSL_KEM_PARAM_FIPS_APPROVED_INDICATOR) <integer>
"key-check" (OSSL_KEM_PARAM_FIPS_KEY_CHECK) <integer>

These parameters are described in provider-kem(7).

Releases

3 releases since Debian 12 (Bookworm); the text changed 2 times.

  1. 12
  2. 13
  3. Arch

Conforming to

SP800-56Br2

Section 7.2.1.2 RSASVE Generate Operation (RSASVE.GENERATE). Section 7.2.1.3 RSASVE Recovery Operation (RSASVE.RECOVER).

History

This functionality was added in OpenSSL 3.0.

The "operation" (operating mode) was a required parameter prior to OpenSSL 3.5. As of OpenSSL 3.5, "RSASVE" is the default operating mode, and no explicit value need be specified.

From openssl 3.6.5-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.