OSSL_PROVIDER-LEGACY(7SSL)

💖 OSSL_PROVIDER-legacy — bestie's guide to the OpenSSL legacy provider 💖

okay so this is the OSSL_PROVIDER-legacy(7SSL) page, and honestly? it's giving retirement home for algorithms. let's get into it 🫶

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✨ NAME ✨

OSSL_PROVIDER-legacy — the OpenSSL legacy provider, aka the place where the old cryptos go to chill.

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🌸 DESCRIPTION 🌸

The OpenSSL legacy provider hands you OpenSSL's implementations of algorithms that have officially been deemed legacy. And like, what does "legacy" mean here? basically these algorithms have commonly fallen out of use, or the cryptography community has deemed them insecure, or, yk, something similar. no cap.

We can consider this the retirement home of cryptographic algorithms. 🏡👵 they lived, they served, they're not invited to new projects anymore.

🌈 Properties 🌈

The implementations in this provider specifically has this property defined:

"provider=legacy"

It may be used in a property query string with fetching functions such as EVP_MD_fetch(3) or EVP_CIPHER_fetch(3), as well as with other functions that take a property query string, such as EVP_PKEY_CTX_new_from_name(3).

It isn't mandatory to query for any of these properties, except to make sure to get implementations of this provider and none other. slay. 💅

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🔥 OPERATIONS AND ALGORITHMS 🔥

The OpenSSL legacy provider supports these operations and algorithms:

⭐ Hashing Algorithms / Message Digests ⭐

• MD2, see EVP_MD-MD2(7)
  • Disabled by default. Use enable-md2 config option to enable.
• MD4, see EVP_MD-MD4(7)
• MDC2, see EVP_MD-MDC2(7)
• WHIRLPOOL, see EVP_MD-WHIRLPOOL(7)
• RIPEMD160, see EVP_MD-RIPEMD160(7)

🦋 Symmetric Ciphers 🦋

Not all of these symmetric cipher algorithms are enabled by default. (some of them are lowkey asleep, wake them up in config 😴)

• Blowfish, see EVP_CIPHER-BLOWFISH(7)
• CAST, see EVP_CIPHER-CAST(7)
• DES, see EVP_CIPHER-DES(7)
  • The algorithm names are: DES_ECB, DES_CBC, DES_OFB, DES_CFB, DES_CFB1, DES_CFB8 and DESX_CBC.
• IDEA, see EVP_CIPHER-IDEA(7)
• RC2, see EVP_CIPHER-RC2(7)
• RC4, see EVP_CIPHER-RC4(7)
• RC5, see EVP_CIPHER-RC5(7)
  • Disabled by default. Use enable-rc5 config option to enable.
• SEED, see EVP_CIPHER-SEED(7)

🎀 Key Derivation Function (KDF) 🎀

• PBKDF1
• PVKKDF

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👀 SEE ALSO 👀

OSSL_PARAM(3), openssl-core.h(7), openssl-core_dispatch.h(7), provider(7)

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📜 HISTORY 📜

This functionality was added in OpenSSL 3.0. so it's not ancient, it just houses ancient things. iconic behavior tbh.

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💜 COPYRIGHT 💜

Copyright 2020-2021 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>.

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and that's the whole page bestie 💖 version 4.0.3, dated 2026-09-29, and yes it's still OSSL_PROVIDER-LEGACY(7SSL) — go forth and fetch responsibly 🧚✨