NAME

       EVP_KDF-PBKDF2 - The PBKDF2 EVP_KDF implementation

DESCRIPTION

       Support for computing the PBKDF2 password-based KDF through the EVP_KDF API.

       The EVP_KDF-PBKDF2 algorithm implements the PBKDF2 password-based key derivation function,
       as described in SP800-132; it derives a key from a password using a salt and iteration
       count.

   Identity
       "PBKDF2" is the name for this implementation; it can be used with the EVP_KDF_fetch()
       function.

   Supported parameters
       The supported parameters are:

       "pass" (OSSL_KDF_PARAM_PASSWORD) <octet string>
       "salt" (OSSL_KDF_PARAM_SALT) <octet string>
       "iter" (OSSL_KDF_PARAM_ITER) <unsigned integer>
           This parameter has a default value of 2048.

       "properties" (OSSL_KDF_PARAM_PROPERTIES) <UTF8 string>
       "digest" (OSSL_KDF_PARAM_DIGEST) <UTF8 string>
           These parameters work as described in "PARAMETERS" in EVP_KDF(3).

       "pkcs5" (OSSL_KDF_PARAM_PKCS5) <integer>
           This parameter can be used to enable or disable SP800-132 compliance checks.  Setting
           the mode to 0 enables the compliance checks.

           The checks performed are:

           - the iteration count is at least 1000.
           - the salt length is at least 128 bits.
           - the derived key length is at least 112 bits.

           The default provider uses a default mode of 1 for backwards compatibility, and the
           fips provider uses a default mode of 0.

           The value string is expected to be a decimal number 0 or 1.

NOTES

       A typical application of this algorithm is to derive keying material for an encryption
       algorithm from a password in the "pass", a salt in "salt", and an iteration count.

       Increasing the "iter" parameter slows down the algorithm which makes it harder for an
       attacker to perform a brute force attack using a large number of candidate passwords.

       No assumption is made regarding the given password; it is simply treated as a byte
       sequence.

CONFORMING TO

       SP800-132

SEE ALSO

       EVP_KDF(3), EVP_KDF_CTX_new(3), EVP_KDF_CTX_free(3), EVP_KDF_CTX_set_params(3),
       EVP_KDF_derive(3), "PARAMETERS" in EVP_KDF(3)

HISTORY

       This functionality was added to OpenSSL 3.0.

COPYRIGHT

       Copyright 2018-2020 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use this file except
       in compliance with the License.  You can obtain a copy in the file LICENSE in the source
       distribution or at <https://www.openssl.org/source/license.html>.