1=pod 2{- OpenSSL::safe::output_do_not_edit_headers(); -} 3 4=head1 NAME 5 6openssl-kdf - perform Key Derivation Function operations 7 8=head1 SYNOPSIS 9 10B<openssl kdf> 11[B<-help>] 12[B<-cipher>] 13[B<-digest>] 14[B<-mac>] 15[B<-kdfopt> I<nm>:I<v>] 16[B<-keylen> I<num>] 17[B<-out> I<filename>] 18[B<-binary>] 19{- $OpenSSL::safe::opt_provider_synopsis -} 20I<kdf_name> 21 22=head1 DESCRIPTION 23 24The key derivation functions generate a derived key from either a secret or 25password. 26 27=head1 OPTIONS 28 29=over 4 30 31=item B<-help> 32 33Print a usage message. 34 35=item B<-keylen> I<num> 36 37The output size of the derived key. This field is required. 38 39=item B<-out> I<filename> 40 41Filename to output to, or standard output by default. 42 43=item B<-binary> 44 45Output the derived key in binary form. Uses hexadecimal text format if not specified. 46 47=item B<-cipher> I<name> 48 49Specify the cipher to be used by the KDF. 50Not all KDFs require a cipher and it is an error to use this option in such 51cases. 52 53=item B<-digest> I<name> 54 55Specify the digest to be used by the KDF. 56Not all KDFs require a digest and it is an error to use this option in such 57cases. 58To see the list of supported digests, use C<openssl list -digest-commands>. 59 60=item B<-mac> I<name> 61 62Specify the MAC to be used by the KDF. 63Not all KDFs require a MAC and it is an error to use this option in such 64cases. 65 66=item B<-kdfopt> I<nm>:I<v> 67 68Passes options to the KDF algorithm. 69A comprehensive list of parameters can be found in the EVP_KDF_CTX 70implementation documentation. 71Common parameter names used by EVP_KDF_CTX_set_params() are: 72 73=over 4 74 75=item B<key:>I<string> 76 77Specifies the secret key as an alphanumeric string (use if the key contains 78printable characters only). 79The string length must conform to any restrictions of the KDF algorithm. 80A key must be specified for most KDF algorithms. 81 82=item B<hexkey:>I<string> 83 84Specifies the secret key in hexadecimal form (two hex digits per byte). 85The key length must conform to any restrictions of the KDF algorithm. 86A key must be specified for most KDF algorithms. 87 88=item B<pass:>I<string> 89 90Specifies the password as an alphanumeric string (use if the password contains 91printable characters only). 92The password must be specified for PBKDF2 and scrypt. 93 94=item B<hexpass:>I<string> 95 96Specifies the password in hexadecimal form (two hex digits per byte). 97The password must be specified for PBKDF2 and scrypt. 98 99=item B<digest:>I<string> 100 101This option is identical to the B<-digest> option. 102 103=item B<cipher:>I<string> 104 105This option is identical to the B<-cipher> option. 106 107=item B<mac:>I<string> 108 109This option is identical to the B<-mac> option. 110 111=back 112 113{- $OpenSSL::safe::opt_provider_item -} 114 115=item I<kdf_name> 116 117Specifies the name of a supported KDF algorithm which will be used. 118The supported algorithms names include TLS1-PRF, HKDF, SSKDF, PBKDF2, 119SSHKDF, X942KDF-ASN1, X942KDF-CONCAT, X963KDF and SCRYPT. 120 121=back 122 123=head1 EXAMPLES 124 125Use TLS1-PRF to create a hex-encoded derived key from a secret key and seed: 126 127 openssl kdf -keylen 16 -kdfopt digest:SHA2-256 -kdfopt key:secret \ 128 -kdfopt seed:seed TLS1-PRF 129 130Use HKDF to create a hex-encoded derived key from a secret key, salt and info: 131 132 openssl kdf -keylen 10 -kdfopt digest:SHA2-256 -kdfopt key:secret \ 133 -kdfopt salt:salt -kdfopt info:label HKDF 134 135Use SSKDF with KMAC to create a hex-encoded derived key from a secret key, salt and info: 136 137 openssl kdf -keylen 64 -kdfopt mac:KMAC-128 -kdfopt maclen:20 \ 138 -kdfopt hexkey:b74a149a161545 -kdfopt hexinfo:348a37a2 \ 139 -kdfopt hexsalt:3638271ccd68a2 SSKDF 140 141Use SSKDF with HMAC to create a hex-encoded derived key from a secret key, salt and info: 142 143 openssl kdf -keylen 16 -kdfopt mac:HMAC -kdfopt digest:SHA2-256 \ 144 -kdfopt hexkey:b74a149a -kdfopt hexinfo:348a37a2 \ 145 -kdfopt hexsalt:3638271c SSKDF 146 147Use SSKDF with Hash to create a hex-encoded derived key from a secret key, salt and info: 148 149 openssl kdf -keylen 14 -kdfopt digest:SHA2-256 \ 150 -kdfopt hexkey:6dbdc23f045488 \ 151 -kdfopt hexinfo:a1b2c3d4 SSKDF 152 153Use SSHKDF to create a hex-encoded derived key from a secret key, hash and session_id: 154 155 openssl kdf -keylen 16 -kdfopt digest:SHA2-256 \ 156 -kdfopt hexkey:0102030405 \ 157 -kdfopt hexxcghash:06090A \ 158 -kdfopt hexsession_id:01020304 \ 159 -kdfopt type:A SSHKDF 160 161Use PBKDF2 to create a hex-encoded derived key from a password and salt: 162 163 openssl kdf -keylen 32 -kdfopt digest:SHA256 -kdfopt pass:password \ 164 -kdfopt salt:salt -kdfopt iter:2 PBKDF2 165 166Use scrypt to create a hex-encoded derived key from a password and salt: 167 168 openssl kdf -keylen 64 -kdfopt pass:password -kdfopt salt:NaCl \ 169 -kdfopt n:1024 -kdfopt r:8 -kdfopt p:16 \ 170 -kdfopt maxmem_bytes:10485760 SCRYPT 171 172=head1 NOTES 173 174The KDF mechanisms that are available will depend on the options 175used when building OpenSSL. 176 177=head1 SEE ALSO 178 179L<openssl(1)>, 180L<openssl-pkeyutl(1)>, 181L<EVP_KDF(3)>, 182L<EVP_KDF-SCRYPT(7)>, 183L<EVP_KDF-TLS1_PRF(7)>, 184L<EVP_KDF-PBKDF2(7)>, 185L<EVP_KDF-HKDF(7)>, 186L<EVP_KDF-SS(7)>, 187L<EVP_KDF-SSHKDF(7)>, 188L<EVP_KDF-X942-ASN1(7)>, 189L<EVP_KDF-X942-CONCAT(7)>, 190L<EVP_KDF-X963(7)> 191 192=head1 HISTORY 193 194Added in OpenSSL 3.0 195 196=head1 COPYRIGHT 197 198Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved. 199 200Licensed under the Apache License 2.0 (the "License"). You may not use 201this file except in compliance with the License. You can obtain a copy 202in the file LICENSE in the source distribution or at 203L<https://www.openssl.org/source/license.html>. 204 205=cut 206
