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. 60This option breaks FIPS compliance if it causes the approved "fips-indicator" 61to return 0. 62 63=item "fips-indicator" (B<OSSL_KDF_PARAM_FIPS_APPROVED_INDICATOR>) <integer> 64 65This option is used by the OpenSSL FIPS provider. 66 67A getter that returns 1 if the operation is FIPS approved, or 0 otherwise. 68This may be used after calling EVP_KDF_derive. It returns 0 if "pkcs5" 69is set to 1 and the derived key length, salt length or iteration count test 70fails. 71 72=back 73 74=head1 NOTES 75 76A typical application of this algorithm is to derive keying material for an 77encryption algorithm from a password in the "pass", a salt in "salt", 78and an iteration count. 79 80Increasing the "iter" parameter slows down the algorithm which makes it 81harder for an attacker to perform a brute force attack using a large number 82of candidate passwords. 83 84No assumption is made regarding the given password; it is simply treated as a 85byte sequence. 86 87=head1 CONFORMING TO 88 89SP800-132 90 91=head1 SEE ALSO 92 93L<EVP_KDF(3)>, 94L<EVP_KDF_CTX_new(3)>, 95L<EVP_KDF_CTX_free(3)>, 96L<EVP_KDF_CTX_set_params(3)>, 97L<EVP_KDF_derive(3)>, 98L<EVP_KDF(3)/PARAMETERS> 99 100=head1 HISTORY 101 102This functionality was added in OpenSSL 3.0. 103 104=head1 COPYRIGHT 105 106Copyright 2018-2024 The OpenSSL Project Authors. All Rights Reserved. 107 108Licensed under the Apache License 2.0 (the "License"). You may not use 109this file except in compliance with the License. You can obtain a copy 110in the file LICENSE in the source distribution or at 111L<https://www.openssl.org/source/license.html>. 112 113=cut 114
