EVP_RC5_32_12_16_CBC(3ossl)

📦
version 15.1 · 2 versions
, in freebsd 15.1

💫 EVP_RC5_32_12_16_CBC(3ossl) — the RC5 cipher, but make it make sense 💫

okay so bestie, this is a page from the OpenSSL manual, and it's all about the RC5 cipher family in EVP. yes, that RC5. the one with the little numbers in the name. let's get into it ✨

🌸 NAME 🌸

EVP_rc5_32_12_16_cbc, EVP_rc5_32_12_16_cfb, EVP_rc5_32_12_16_cfb64, EVP_rc5_32_12_16_ecb, EVP_rc5_32_12_16_ofb — literally the EVP RC5 cipher. that's the whole vibe. 💅

🎀 SYNOPSIS 🎀

#include <openssl/evp.h>

const EVP_CIPHER *EVP_rc5_32_12_16_cbc(void);
const EVP_CIPHER *EVP_rc5_32_12_16_cfb(void);
const EVP_CIPHER *EVP_rc5_32_12_16_cfb64(void);
const EVP_CIPHER *EVP_rc5_32_12_16_ecb(void);
const EVP_CIPHER *EVP_rc5_32_12_16_ofb(void);

look at them. five little functions. all iconic, all returning a const EVP_CIPHER *. 🫶

🦋 DESCRIPTION 🦋

so, the RC5 encryption algorithm, but for EVP. that's the summary, that's the post. ✨

💜 EVP_rc5_32_12_16_cbc(), EVP_rc5_32_12_16_cfb(), EVP_rc5_32_12_16_cfb64(), EVP_rc5_32_12_16_ecb(), EVP_rc5_32_12_16_ofb()

these give you the RC5 encryption algorithm in CBC, CFB, ECB and OFB modes respectively. no cap, one function per mode. 🌈

here's the main character detail: this is a variable key length cipher with an extra "number of rounds" parameter. so it's not just "set it and forget it" — you got options, bestie. 👑

by default the key length is set to 128 bits and 12 rounds. yes, that's where the 32_12_16 energy comes from, bestie noticed. 🔥

alternative key lengths can be set using EVP_CIPHER_CTX_set_key_length(3). and the maximum key length is 2040 bits. that's not a typo, that's two thousand and forty. 😭

🧚 the rc5 specific ctrls

these are supported — see EVP_CIPHER_CTX_ctrl(3):

  • EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC5_ROUNDS, rounds, NULL) — sets the number of rounds to rounds. this must be one of RC5_8_ROUNDS, RC5_12_ROUNDS or RC5_16_ROUNDS. no custom round counts, she has a type. 💅
  • EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC5_ROUNDS, 0, &rounds) — stores the number of rounds currently configured in *rounds, where *rounds is an int. 🍓

⚡ NOTES ⚡

developers should be aware of the negative performance implications of calling these functions multiple times 😬 and should consider using EVP_CIPHER_fetch(3) with EVP_CIPHER-RC5(7) instead. see "Performance" in crypto(7) for further information. like, she's telling you for your own good, fr fr. 🙈

👑 RETURN VALUES 👑

these functions return an EVP_CIPHER structure that contains the implementation of the symmetric cipher. see EVP_CIPHER_meth_new(3) for details of the EVP_CIPHER structure. that's it, that's the return. simple, clean, slay. ✨

🌺 SEE ALSO 🌺

go read those next, bestie, iykyk. 📚

Copyright 2017-2023 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>.

aaaand that's the whole page, bestie!! 🎀 no details left behind, we ate and left no crumbs. stay ciphering 💅✨

version 3.5.6, dated 2026-04-07 — mwah, from your favorite manual page 🫶

📦 where this page comes from