1=pod 2 3=head1 NAME 4 5EVP_KDF-PBKDF2 - The PBKDF2 EVP_KDF implementation 6 7=head1 DESCRIPTION 8 9Support for computing the B<PBKDF2> password-based KDF through the B<EVP_KDF> 10API. 11 12The EVP_KDF-PBKDF2 algorithm implements the PBKDF2 password-based key 13derivation function, as described in SP800-132; it derives a key from a password 14using a salt and iteration count. 15 16=head2 Identity 17 18"PBKDF2" is the name for this implementation; it 19can be used with the EVP_KDF_fetch() function. 20 21=head2 Supported parameters 22 23The supported parameters are: 24 25=over 4 26 27=item "pass" (B<OSSL_KDF_PARAM_PASSWORD>) <octet string> 28 29=item "salt" (B<OSSL_KDF_PARAM_SALT>) <octet string> 30 31=item "iter" (B<OSSL_KDF_PARAM_ITER>) <unsigned integer> 32 33This parameter has a default value of 2048. 34 35=item "properties" (B<OSSL_KDF_PARAM_PROPERTIES>) <UTF8 string> 36 37=item "digest" (B<OSSL_KDF_PARAM_DIGEST>) <UTF8 string> 38 39These parameters work as described in L<EVP_KDF(3)/PARAMETERS>. 40 41=item "pkcs5" (B<OSSL_KDF_PARAM_PKCS5>) <integer> 42 43This parameter can be used to enable or disable SP800-132 compliance checks. 44Setting the mode to 0 enables the compliance checks. 45 46The checks performed are: 47 48=over 4 49 50=item - the iteration count is at least 1000. 51 52=item - the salt length is at least 128 bits. 53 54=item - the derived key length is at least 112 bits. 55 56=back 57 58The default provider uses a default mode of 1 for backwards compatibility, 59and the FIPS provider uses a default mode of 0. 60 61The value string is expected to be a decimal number 0 or 1. 62 63=back 64 65=head1 NOTES 66 67A typical application of this algorithm is to derive keying material for an 68encryption algorithm from a password in the "pass", a salt in "salt", 69and an iteration count. 70 71Increasing the "iter" parameter slows down the algorithm which makes it 72harder for an attacker to perform a brute force attack using a large number 73of candidate passwords. 74 75No assumption is made regarding the given password; it is simply treated as a 76byte sequence. 77 78=head1 CONFORMING TO 79 80SP800-132 81 82=head1 SEE ALSO 83 84L<EVP_KDF(3)>, 85L<EVP_KDF_CTX_new(3)>, 86L<EVP_KDF_CTX_free(3)>, 87L<EVP_KDF_CTX_set_params(3)>, 88L<EVP_KDF_derive(3)>, 89L<EVP_KDF(3)/PARAMETERS> 90 91=head1 HISTORY 92 93This functionality was added in OpenSSL 3.0. 94 95=head1 COPYRIGHT 96 97Copyright 2018-2022 The OpenSSL Project Authors. All Rights Reserved. 98 99Licensed under the Apache License 2.0 (the "License"). You may not use 100this file except in compliance with the License. You can obtain a copy 101in the file LICENSE in the source distribution or at 102L<https://www.openssl.org/source/license.html>. 103 104=cut 105