EVP_CAST5_CBC(3ossl)

💖 EVP_CAST5_CBC — the OpenSSL manual, but make it make sense 💖

okay bestie, pull up a chair 🫶 this is EVP_CAST5_CBC(3ossl) from the OpenSSL fam, and we're gonna talk about the CAST cipher and its whole little friend group of EVP functions. no cap, it's shorter than you think.

---

✨ NAME ✨

EVP_cast5_cbc, EVP_cast5_cfb, EVP_cast5_cfb64, EVP_cast5_ecb, EVP_cast5_ofb — it's giving EVP CAST cipher, and honestly? iconic. 👑

---

🌸 SYNOPSIS 🌸

#include <openssl/evp.h>

const EVP_CIPHER *EVP_cast5_cbc(void);
const EVP_CIPHER *EVP_cast5_cfb(void);
const EVP_CIPHER *EVP_cast5_cfb64(void);
const EVP_CIPHER *EVP_cast5_ecb(void);
const EVP_CIPHER *EVP_cast5_ofb(void);

five little functions, all returning a const EVP_CIPHER *, all taking void (so like, no arguments, she doesn't want your input 💅).

---

🦋 DESCRIPTION 🦋

so basically: this is the CAST encryption algorithm for EVP. that's the whole vibe.

and the tea is — this is a variable key length cipher. meaning the key length isn't locked in, it flexes. main character energy, honestly. ✨

now the lineup, one by one:

• EVP_cast5_cbc(), EVP_cast5_ecb(), EVP_cast5_cfb(), EVP_cast5_cfb64(), EVP_cast5_ofb() — these give you the CAST encryption algorithm in CBC, ECB, CFB and OFB modes respectively. like, same girl, different outfits. each one matches the mode in her name, iykyk. 🎀

---

💀 NOTES 💀

okay this part matters, don't skip it bestie 😭

devs should be aware of the negative performance implications of calling these functions multiple times — like, it's not free, okay?? and instead you should consider using EVP_CIPHER_fetch(3) with EVP_CIPHER-CAST(7).

for the full rundown, go read "Performance" in crypto(7). it's all there, fr fr. 📖

---

🌈 RETURN VALUES 🌈

these functions return an EVP_CIPHER structure that contains the implementation of the symmetric cipher. that's the whole return value, that's the gift 🎁

want the deets on what's actually inside that EVP_CIPHER structure? EVP_CIPHER_meth_new(3) has you covered. 🫶

---

👑 SEE ALSO 👑

• evp(7)
• EVP_EncryptInit(3)
• EVP_CIPHER_meth_new(3)

go read those next, bestie, the lore is deep 💜

---

🎀 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>.

---

and that's the whole page, periodt 💅 this was OpenSSL 3.5.9, dated 2026-09-29, and yes the footer really did say EVP_CAST5_CBC(3ossl) — slay, go encrypt something responsibly 🌸🦋