2 {- OpenSSL::safe::output_do_not_edit_headers(); -}
6 openssl-kdf - perform Key Derivation Function operations
15 [B<-kdfopt> I<nm>:I<v>]
19 {- $OpenSSL::safe::opt_provider_synopsis -}
24 The key derivation functions generate a derived key from either a secret or
33 Print a usage message.
35 =item B<-keylen> I<num>
37 The output size of the derived key. This field is required.
39 =item B<-out> I<filename>
41 Filename to output to, or standard output by default.
45 Output the derived key in binary form. Uses hexadecimal text format if not specified.
47 =item B<-cipher> I<name>
49 Specify the cipher to be used by the KDF.
50 Not all KDFs require a cipher and it is an error to use this option in such
53 =item B<-digest> I<name>
55 Specify the digest to be used by the KDF.
56 Not all KDFs require a digest and it is an error to use this option in such
58 To see the list of supported digests, use C<openssl list -digest-commands>.
62 Specify the MAC to be used by the KDF.
63 Not all KDFs require a MAC and it is an error to use this option in such
66 =item B<-kdfopt> I<nm>:I<v>
68 Passes options to the KDF algorithm.
69 A comprehensive list of parameters can be found in L<EVP_KDF(3)/PARAMETERS>.
70 Common parameter names used by EVP_KDF_CTX_set_params() are:
74 =item B<key:>I<string>
76 Specifies the secret key as an alphanumeric string (use if the key contains
77 printable characters only).
78 The string length must conform to any restrictions of the KDF algorithm.
79 A key must be specified for most KDF algorithms.
81 =item B<hexkey:>I<string>
83 Alternative to the B<key:> option where
84 the secret key is specified in hexadecimal form (two hex digits per byte).
86 =item B<pass:>I<string>
88 Specifies the password as an alphanumeric string (use if the password contains
89 printable characters only).
90 The password must be specified for PBKDF2 and scrypt.
92 =item B<hexpass:>I<string>
94 Alternative to the B<pass:> option where
95 the password is specified in hexadecimal form (two hex digits per byte).
97 =item B<salt:>I<string>
99 Specifies a non-secret unique cryptographic salt as an alphanumeric string
100 (use if it contains printable characters only).
101 The length must conform to any restrictions of the KDF algorithm.
102 A salt parameter is required for several KDF algorithms,
103 such as L<EVP_KDF-PBKDF2(7)>.
105 =item B<hexsalt:>I<string>
107 Alternative to the B<salt:> option where
108 the salt is specified in hexadecimal form (two hex digits per byte).
110 =item B<info:>I<string>
112 Some KDF implementations, such as L<EVP_KDF-HKDF(7)>, take an 'info' parameter
113 for binding the derived key material
114 to application- and context-specific information.
115 Specifies the info, fixed info, other info or shared info argument
116 as an alphanumeric string (use if it contains printable characters only).
117 The length must conform to any restrictions of the KDF algorithm.
119 =item B<hexinfo:>I<string>
121 Alternative to the B<info:> option where
122 the info is specified in hexadecimal form (two hex digits per byte).
124 =item B<digest:>I<string>
126 This option is identical to the B<-digest> option.
128 =item B<cipher:>I<string>
130 This option is identical to the B<-cipher> option.
132 =item B<mac:>I<string>
134 This option is identical to the B<-mac> option.
138 {- $OpenSSL::safe::opt_provider_item -}
142 Specifies the name of a supported KDF algorithm which will be used.
143 The supported algorithms names include TLS1-PRF, HKDF, SSKDF, PBKDF2,
144 SSHKDF, X942KDF-ASN1, X942KDF-CONCAT, X963KDF and SCRYPT.
150 Use TLS1-PRF to create a hex-encoded derived key from a secret key and seed:
152 openssl kdf -keylen 16 -kdfopt digest:SHA2-256 -kdfopt key:secret \
153 -kdfopt seed:seed TLS1-PRF
155 Use HKDF to create a hex-encoded derived key from a secret key, salt and info:
157 openssl kdf -keylen 10 -kdfopt digest:SHA2-256 -kdfopt key:secret \
158 -kdfopt salt:salt -kdfopt info:label HKDF
160 Use SSKDF with KMAC to create a hex-encoded derived key from a secret key, salt and info:
162 openssl kdf -keylen 64 -kdfopt mac:KMAC-128 -kdfopt maclen:20 \
163 -kdfopt hexkey:b74a149a161545 -kdfopt hexinfo:348a37a2 \
164 -kdfopt hexsalt:3638271ccd68a2 SSKDF
166 Use SSKDF with HMAC to create a hex-encoded derived key from a secret key, salt and info:
168 openssl kdf -keylen 16 -kdfopt mac:HMAC -kdfopt digest:SHA2-256 \
169 -kdfopt hexkey:b74a149a -kdfopt hexinfo:348a37a2 \
170 -kdfopt hexsalt:3638271c SSKDF
172 Use SSKDF with Hash to create a hex-encoded derived key from a secret key, salt and info:
174 openssl kdf -keylen 14 -kdfopt digest:SHA2-256 \
175 -kdfopt hexkey:6dbdc23f045488 \
176 -kdfopt hexinfo:a1b2c3d4 SSKDF
178 Use SSHKDF to create a hex-encoded derived key from a secret key, hash and session_id:
180 openssl kdf -keylen 16 -kdfopt digest:SHA2-256 \
181 -kdfopt hexkey:0102030405 \
182 -kdfopt hexxcghash:06090A \
183 -kdfopt hexsession_id:01020304 \
184 -kdfopt type:A SSHKDF
186 Use PBKDF2 to create a hex-encoded derived key from a password and salt:
188 openssl kdf -keylen 32 -kdfopt digest:SHA256 -kdfopt pass:password \
189 -kdfopt salt:salt -kdfopt iter:2 PBKDF2
191 Use scrypt to create a hex-encoded derived key from a password and salt:
193 openssl kdf -keylen 64 -kdfopt pass:password -kdfopt salt:NaCl \
194 -kdfopt n:1024 -kdfopt r:8 -kdfopt p:16 \
195 -kdfopt maxmem_bytes:10485760 SCRYPT
199 The KDF mechanisms that are available will depend on the options
200 used when building OpenSSL.
205 L<openssl-pkeyutl(1)>,
207 L<EVP_KDF-SCRYPT(7)>,
208 L<EVP_KDF-TLS1_PRF(7)>,
209 L<EVP_KDF-PBKDF2(7)>,
212 L<EVP_KDF-SSHKDF(7)>,
213 L<EVP_KDF-X942-ASN1(7)>,
214 L<EVP_KDF-X942-CONCAT(7)>,
223 Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.
225 Licensed under the Apache License 2.0 (the "License"). You may not use
226 this file except in compliance with the License. You can obtain a copy
227 in the file LICENSE in the source distribution or at
228 L<https://www.openssl.org/source/license.html>.