EVP_RC5_32_12_16_CBC(3ossl)

💅 NAME 💅

okay so bestie, welcome to EVP_RC5_32_12_16_CBC(3ossl) — the OpenSSL manual page for the EVP RC5 cipher 🎀

the whole squad of functions on this page is: EVP_rc5_32_12_16_cbc, EVP_rc5_32_12_16_cfb, EVP_rc5_32_12_16_cfb64, EVP_rc5_32_12_16_ecb, and EVP_rc5_32_12_16_ofb — and they're all literally just the EVP RC5 cipher ✨

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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 🎀

it's the RC5 encryption algorithm, but for EVP 🫶

🌸 the five functions 🌸

• 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 bad boys give you the RC5 encryption algorithm in CBC, CFB, ECB and OFB modes respectively 💫

and here's the iconic part: this is a variable key length cipher with an extra "number of rounds" parameter 👑

• 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 rc5-specific ctrls 🦋

these are supported too — see EVP_CIPHER_CTX_ctrl(3) for the deets:

EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC5_ROUNDS, rounds, NULL)

sets the number of rounds to rounds. no cap, this must be one of RC5_8_ROUNDS, RC5_12_ROUNDS or RC5_16_ROUNDS 💀

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 🔥

bestie, hear me out — there are negative performance implications of calling these functions multiple times 😭 so maybe consider using EVP_CIPHER_fetch(3) with EVP_CIPHER-RC5(7) instead ✨ see "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 🫶 see EVP_CIPHER_meth_new(3) if you wanna know what's inside that EVP_CIPHER structure 👀

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🧚 SEE ALSO 🧚

• evp(7)
• EVP_EncryptInit(3)
• EVP_CIPHER_meth_new(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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okay that's the whole page, mwah 💋 — this was version 3.5.0, dated 2026-09-25, and yes the title is still EVP_RC5_32_12_16_CBC(3ossl) because we don't do name changes around here 🎀✨🌸