EVP_RC5_32_12_16_CBC(3SSL)

✨ 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 — bestie, it's the EVP RC5 cipher 💅

This page lives in the OpenSSL manual, so if you're looking for it by name, it's EVP_RC5_32_12_16_CBC(3SSL) 🎀

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🌸 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);

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🦋 DESCRIPTION 🦋

Okay so, this is the RC5 encryption algorithm, but for EVP 🫶

• 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.

This is a variable key length cipher, and she also carries an extra little "number of rounds" parameter, like a bonus accessory ✨ By default the key length is set to 128 bits and 12 rounds. You can set alternative key lengths with EVP_CIPHER_CTX_set_key_length(3). The maximum key length is 2040 bits.

The following rc5 specific ctrls are supported — go peek at EVP_CIPHER_CTX_ctrl(3) for the whole vibe:

• 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. Periodt, those are the only options 💀
• 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 👑

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⚠️ NOTES ⚠️

Devs, listen up bestie: there are negative performance implications of calling these functions multiple times 😭 So you should consider using EVP_CIPHER_fetch(3) with EVP_CIPHER-RC5(7) instead. Go read "Performance" in crypto(7) for the full tea 🌈

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💖 RETURN VALUES 💖

These functions return an EVP_CIPHER structure that contains the implementation of the symmetric cipher. Slay, that's it 🌸

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👑 SEE ALSO 👑

evp(7), EVP_EncryptInit(3)

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🎀 COPYRIGHT 🎀

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>.

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And that's the whole page, babe — this was 4.0.3, dated 2026-09-29, straight from the OpenSSL manual under EVP_RC5_32_12_16_CBC(3SSL). Go forth and encrypt responsibly 🧚💜