B<openssl kdf>
[B<-help>]
+[B<-cipher>]
+[B<-digest>]
+[B<-mac>]
[B<-kdfopt> I<nm>:I<v>]
[B<-keylen> I<num>]
[B<-out> I<filename>]
Output the derived key in binary form. Uses hexadecimal text format if not specified.
+=item B<-cipher> I<name>
+
+Specify the cipher to be used by the KDF.
+Not all KDFs require a cipher and it is an error to use this option in such
+cases.
+
+=item B<-digest> I<name>
+
+Specify the digest to be used by the KDF.
+Not all KDFs require a digest and it is an error to use this option in such
+cases.
+To see the list of supported digests, use C<openssl list -digest-commands>.
+
+=item B<-mac> I<name>
+
+Specify the MAC to be used by the KDF.
+Not all KDFs require a MAC and it is an error to use this option in such
+cases.
+
=item B<-kdfopt> I<nm>:I<v>
Passes options to the KDF algorithm.
-A comprehensive list of parameters can be found in the EVP_KDF_CTX
-implementation documentation.
-Common parameter names used by EVP_KDF_set_ctx_params() are:
+A comprehensive list of parameters can be found in L<EVP_KDF(3)/PARAMETERS>.
+Common parameter names used by EVP_KDF_CTX_set_params() are:
=over 4
=item B<hexkey:>I<string>
-Specifies the secret key in hexadecimal form (two hex digits per byte).
-The key length must conform to any restrictions of the KDF algorithm.
-A key must be specified for most KDF algorithms.
+Alternative to the B<key:> option where
+the secret key is specified in hexadecimal form (two hex digits per byte).
=item B<pass:>I<string>
=item B<hexpass:>I<string>
-Specifies the password in hexadecimal form (two hex digits per byte).
-The password must be specified for PBKDF2 and scrypt.
+Alternative to the B<pass:> option where
+the password is specified in hexadecimal form (two hex digits per byte).
+
+=item B<salt:>I<string>
+
+Specifies a non-secret unique cryptographic salt as an alphanumeric string
+(use if it contains printable characters only).
+The length must conform to any restrictions of the KDF algorithm.
+A salt parameter is required for several KDF algorithms,
+such as L<EVP_KDF-PBKDF2(7)>.
+
+=item B<hexsalt:>I<string>
+
+Alternative to the B<salt:> option where
+the salt is specified in hexadecimal form (two hex digits per byte).
+
+=item B<info:>I<string>
+
+Some KDF implementations, such as L<EVP_KDF-HKDF(7)>, take an 'info' parameter
+for binding the derived key material
+to application- and context-specific information.
+Specifies the info, fixed info, other info or shared info argument
+as an alphanumeric string (use if it contains printable characters only).
+The length must conform to any restrictions of the KDF algorithm.
+
+=item B<hexinfo:>I<string>
+
+Alternative to the B<info:> option where
+the info is specified in hexadecimal form (two hex digits per byte).
=item B<digest:>I<string>
-Specifies the name of a digest as an alphanumeric string.
-To see the list of supported digests, use the command I<list -digest-commands>.
+This option is identical to the B<-digest> option.
+
+=item B<cipher:>I<string>
+
+This option is identical to the B<-cipher> option.
+
+=item B<mac:>I<string>
+
+This option is identical to the B<-mac> option.
=back
Specifies the name of a supported KDF algorithm which will be used.
The supported algorithms names include TLS1-PRF, HKDF, SSKDF, PBKDF2,
-SSHKDF, X942KDF, X963KDF and SCRYPT.
+SSHKDF, X942KDF-ASN1, X942KDF-CONCAT, X963KDF and SCRYPT.
=back
Use scrypt to create a hex-encoded derived key from a password and salt:
openssl kdf -keylen 64 -kdfopt pass:password -kdfopt salt:NaCl \
- -kdfopt N:1024 -kdfopt r:8 -kdfopt p:16 \
+ -kdfopt n:1024 -kdfopt r:8 -kdfopt p:16 \
-kdfopt maxmem_bytes:10485760 SCRYPT
=head1 NOTES
L<EVP_KDF-HKDF(7)>,
L<EVP_KDF-SS(7)>,
L<EVP_KDF-SSHKDF(7)>,
-L<EVP_KDF-X942(7)>,
+L<EVP_KDF-X942-ASN1(7)>,
+L<EVP_KDF-X942-CONCAT(7)>,
L<EVP_KDF-X963(7)>
=head1 HISTORY
=head1 COPYRIGHT
-Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2019-2023 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