Add HPKE DHKEM provider support for EC, X25519 and X448.

[openssl.git] / doc / man7 / EVP_PKEY-X25519.pod

diff --git a/doc/man7/EVP_PKEY-X25519.pod b/doc/man7/EVP_PKEY-X25519.pod
index 9e13e15f7f4fbabd9747db6622d75a0d28cff125..a63e50baa8322164c1c51760ef3fb3bd7d2bd081 100644 (file)
--- a/doc/man7/EVP_PKEY-X25519.pod
+++ b/doc/man7/EVP_PKEY-X25519.pod
@@ -13,8 +13,22 @@ implemented in OpenSSL's default and FIPS providers.  These implementations
 support the associated key, containing the public key I<pub> and the
 private key I<priv>.
 
-No additional parameters can be set during key generation.
+=head2 Keygen Parameters
 
+=over 4
+
+=item "dhkem-ikm" (B<OSSL_PKEY_PARAM_DHKEM_IKM>) <octet string>
+
+DHKEM requires the generation of a keypair using an input key material (seed).
+Use this to specify the key material used for generation of the private key.
+This value should not be reused for other purposes.
+It should have a length of at least 32 for X25519, and 56 for X448.
+
+This is only supported by X25519 and X448.
+
+=back
+
+Use EVP_PKEY_CTX_set_params() after calling EVP_PKEY_keygen_init().
 
 =head2 Common X25519, X448, ED25519 and ED448 parameters