EVP_KDF-PBKDF2(7ossl)

📦 version 3.5.0, in opensuse-leap 16.0

✨ NAME ✨

EVP_KDF-PBKDF2 — The PBKDF2 EVP_KDF implementation. That's it, that's the whole vibe. 💖 And yes bestie, this is the 7ossl manual from OpenSSL, hi! 👋

🌸 DESCRIPTION 🌸

Okay so this page is all about computing the PBKDF2 password-based KDF through the EVP_KDF API, and honestly it's giving secure. 🦋

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. No cap. ✨

The output is considered to be a cryptographic key. Periodt. 🔑

🦋 Identity 🦋

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

🎀 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. So if you don't set it, it's literally 2048, bestie. 💅
  • "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). iykyk. 🧚
  • "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. This option breaks FIPS compliance if it causes the approved "fips-indicator" to return 0. So like, handle with care, okay? 😭

  • "fips-indicator" (OSSL_KDF_PARAM_FIPS_APPROVED_INDICATOR) <integer> — this option is used by the OpenSSL FIPS provider. A getter that returns 1 if the operation is FIPS approved, or 0 otherwise. This may be used after calling EVP_KDF_derive. It returns 0 if "pkcs5" is set to 1 and the derived key length, salt length or iteration count test fails. It's giving "trust but verify" energy. 🔍

💅 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. Classic. 👑

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. So like, higher iter is doing the most for your security. 🔥

No assumption is made regarding the given password; it is simply treated as a byte sequence. No judgment, no assumptions, just bytes. 💜

⭐ CONFORMING TO ⭐

SP800-132. That's the standard, bestie. 🎀

🔥 SEE ALSO 🔥

🎀 HISTORY 🎀

This functionality was added in OpenSSL 3.0. So it's not new new, but it's iconic. 🌈

Copyright 2018-2024 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>.

and that's the whole page, bestie! This was EVP_KDF-PBKDF2(7ossl) from OpenSSL version 3.5.0, dated 2026-09-25. Stay cryptographic, stay slay. 💅✨🫶

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