1=pod 2 3=head1 NAME 4 5EVP_PKEY-X25519, EVP_PKEY-X448, EVP_PKEY-ED25519, EVP_PKEY-ED448, 6EVP_KEYMGMT-X25519, EVP_KEYMGMT-X448, EVP_KEYMGMT-ED25519, EVP_KEYMGMT-ED448 7- EVP_PKEY X25519, X448, ED25519 and ED448 keytype and algorithm support 8 9=head1 DESCRIPTION 10 11The B<X25519>, B<X448>, B<ED25519> and B<ED448> keytypes are 12implemented in OpenSSL's default and FIPS providers. These implementations 13support the associated key, containing the public key I<pub> and the 14private key I<priv>. 15 16=head2 Keygen Parameters 17 18=over 4 19 20=item "dhkem-ikm" (B<OSSL_PKEY_PARAM_DHKEM_IKM>) <octet string> 21 22DHKEM requires the generation of a keypair using an input key material (seed). 23Use this to specify the key material used for generation of the private key. 24This value should not be reused for other purposes. 25It should have a length of at least 32 for X25519, and 56 for X448. 26This is only supported by X25519 and X448. 27 28=item "fips-indicator" (B<OSSL_PKEY_PARAM_FIPS_APPROVED_INDICATOR>) <integer> 29 30This getter is only supported by X25519 and X448 for the FIPS provider. 31Since X25519 and X448 are unapproved in FIPS 140-3 this getter return 0. 32 33See L<provider-keymgmt(7)/Common Information Parameters> for further information. 34 35=back 36 37Use EVP_PKEY_CTX_set_params() after calling EVP_PKEY_keygen_init(). 38 39=head2 Common X25519, X448, ED25519 and ED448 parameters 40 41In addition to the common parameters that all keytypes should support (see 42L<provider-keymgmt(7)/Common parameters>), the implementation of these keytypes 43support the following. 44 45=over 4 46 47=item "group" (B<OSSL_PKEY_PARAM_GROUP_NAME>) <UTF8 string> 48 49This is only supported by X25519 and X448. The group name must be "x25519" or 50"x448" respectively for those algorithms. This is only present for consistency 51with other key exchange algorithms and is typically not needed. 52 53=item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <octet string> 54 55The public key value. 56 57=item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <octet string> 58 59The private key value. 60 61=item "encoded-pub-key" (B<OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY>) <octet string> 62 63Used for getting and setting the encoding of a public key for the B<X25519> and 64B<X448> key types. Public keys are expected be encoded in a format as defined by 65RFC7748. 66 67=back 68 69=head2 ED25519 and ED448 parameters 70 71=over 4 72 73=item "mandatory-digest" (B<OSSL_PKEY_PARAM_MANDATORY_DIGEST>) <UTF8 string> 74 75The empty string, signifying that no digest may be specified. 76 77=back 78 79=head1 CONFORMING TO 80 81=over 4 82 83=item RFC 8032 84 85=item RFC 8410 86 87=back 88 89=head1 EXAMPLES 90 91An B<EVP_PKEY> context can be obtained by calling: 92 93 EVP_PKEY_CTX *pctx = 94 EVP_PKEY_CTX_new_from_name(NULL, "X25519", NULL); 95 96 EVP_PKEY_CTX *pctx = 97 EVP_PKEY_CTX_new_from_name(NULL, "X448", NULL); 98 99 EVP_PKEY_CTX *pctx = 100 EVP_PKEY_CTX_new_from_name(NULL, "ED25519", NULL); 101 102 EVP_PKEY_CTX *pctx = 103 EVP_PKEY_CTX_new_from_name(NULL, "ED448", NULL); 104 105An B<X25519> key can be generated like this: 106 107 pkey = EVP_PKEY_Q_keygen(NULL, NULL, "X25519"); 108 109An B<X448>, B<ED25519>, or B<ED448> key can be generated likewise. 110 111=head1 SEE ALSO 112 113L<EVP_KEYMGMT(3)>, L<EVP_PKEY(3)>, L<provider-keymgmt(7)>, 114L<EVP_KEYEXCH-X25519(7)>, L<EVP_KEYEXCH-X448(7)>, 115L<EVP_SIGNATURE-ED25519(7)>, L<EVP_SIGNATURE-ED448(7)> 116 117=head1 COPYRIGHT 118 119Copyright 2020-2024 The OpenSSL Project Authors. All Rights Reserved. 120 121Licensed under the Apache License 2.0 (the "License"). You may not use 122this file except in compliance with the License. You can obtain a copy 123in the file LICENSE in the source distribution or at 124L<https://www.openssl.org/source/license.html>. 125 126=cut 127
