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 16The output is considered to be a cryptographic key. 17 18=head2 Identity 19 20"PBKDF2" is the name for this implementation; it 21can be used with the EVP_KDF_fetch() function. 22 23=head2 Supported parameters 24 25The supported parameters are: 26 27=over 4 28 29=item "pass" (B<OSSL_KDF_PARAM_PASSWORD>) <octet string> 30 31=item "salt" (B<OSSL_KDF_PARAM_SALT>) <octet string> 32 33=item "iter" (B<OSSL_KDF_PARAM_ITER>) <unsigned integer> 34 35This parameter has a default value of 2048. 36 37=item "properties" (B<OSSL_KDF_PARAM_PROPERTIES>) <UTF8 string> 38 39=item "digest" (B<OSSL_KDF_PARAM_DIGEST>) <UTF8 string> 40 41These parameters work as described in L<EVP_KDF(3)/PARAMETERS>. 42 43=item "pkcs5" (B<OSSL_KDF_PARAM_PKCS5>) <integer> 44 45This parameter can be used to enable or disable SP800-132 compliance checks. 46Setting the mode to 0 enables the compliance checks. 47 48The checks performed are: 49 50=over 4 51 52=item - the iteration count is at least 1000. 53 54=item - the salt length is at least 128 bits. 55 56=item - the derived key length is at least 112 bits. 57 58=back 59 60The default provider uses a default mode of 1 for backwards compatibility, 61and the FIPS provider uses a default mode of 0. 62This option breaks FIPS compliance if it causes the approved "fips-indicator" 63to return 0. 64 65=item "fips-indicator" (B<OSSL_KDF_PARAM_FIPS_APPROVED_INDICATOR>) <integer> 66 67This option is used by the OpenSSL FIPS provider. 68 69A getter that returns 1 if the operation is FIPS approved, or 0 otherwise. 70This may be used after calling EVP_KDF_derive. It returns 0 if "pkcs5" 71is set to 1 and the derived key length, salt length or iteration count test 72fails. 73 74=back 75 76=head1 NOTES 77 78A typical application of this algorithm is to derive keying material for an 79encryption algorithm from a password in the "pass", a salt in "salt", 80and an iteration count. 81 82Increasing the "iter" parameter slows down the algorithm which makes it 83harder for an attacker to perform a brute force attack using a large number 84of candidate passwords. 85 86No assumption is made regarding the given password; it is simply treated as a 87byte sequence. 88 89=head1 CONFORMING TO 90 91SP800-132 92 93=head1 SEE ALSO 94 95L<EVP_KDF(3)>, 96L<EVP_KDF_CTX_new(3)>, 97L<EVP_KDF_CTX_free(3)>, 98L<EVP_KDF_CTX_set_params(3)>, 99L<EVP_KDF_derive(3)>, 100L<EVP_KDF(3)/PARAMETERS> 101 102=head1 HISTORY 103 104This functionality was added in OpenSSL 3.0. 105 106=head1 COPYRIGHT 107 108Copyright 2018-2024 The OpenSSL Project Authors. All Rights Reserved. 109 110Licensed under the Apache License 2.0 (the "License"). You may not use 111this file except in compliance with the License. You can obtain a copy 112in the file LICENSE in the source distribution or at 113L<https://www.openssl.org/source/license.html>. 114 115=cut 116
