EVP_KEYEXCH-X25519, EVP_KEYEXCH-X448 - X25519 and X448 Key Exchange algorithm support

Copyright 2020-2024 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>. 3.5.0 2025-06-04 EVP_KEYEXCH-X25519(7SSL)

Key exchange support for the X25519 and X448 key types. Keyexchangeparameters "pad" (OSSL_EXCHANGE_PARAM_PAD) <unsigned integer> "fips-indicator" (OSSL_EXCHANGE_PARAM_FIPS_APPROVED_INDICATOR) <integer> X25519 and X448 are not FIPS approved in FIPS 140-3. So this getter will return 0. See "Common Key Exchange parameters" in provider-keyexch(7).

Keys for the host and peer can be generated as shown in "Examples" in EVP_PKEY-X25519(7). The code to generate a shared secret is identical to "Examples" in EVP_KEYEXCH-DH(7).

EVP_KEYEXCH-X25519, EVP_KEYEXCH-X448 - X25519 and X448 Key Exchange algorithm support

EVP_PKEY-FFC(7), EVP_PKEY-DH(7) EVP_PKEY(3), provider-keyexch(7), provider-keymgmt(7), OSSL_PROVIDER-default(7), OSSL_PROVIDER-FIPS(7),