EVP_SEED_CBC(3SSL)

👑 EVP_SEED_CBC — the EVP SEED cipher, bestie edition

okay so this is from the OpenSSL manual, section 3SSL, and it's literally the glow-up guide to the SEED cipher. it's giving "crypto but make it cute". let's go 💅

---

✨ NAME ✨

EVP_seed_cbc, EVP_seed_cfb, EVP_seed_cfb128, EVP_seed_ecb, EVP_seed_ofb — the EVP SEED cipher. that's the whole vibe. 🦋

---

🌸 SYNOPSIS 🌸

#include <openssl/evp.h>

const EVP_CIPHER *EVP_seed_cbc(void);
const EVP_CIPHER *EVP_seed_cfb(void);
const EVP_CIPHER *EVP_seed_cfb128(void);
const EVP_CIPHER *EVP_seed_ecb(void);
const EVP_CIPHER *EVP_seed_ofb(void);

five little functions, all returning a const EVP_CIPHER *, no args, no drama. iconic behavior tbh. ✨

---

💖 DESCRIPTION 💖

so the SEED encryption algorithm, but for EVP. that's it, that's the tweet. 🎀

every single mode down below uses a key length of 128 bits and acts on blocks of 128 bits. no cap, both of those are 128.

• EVP_seed_cbc(), EVP_seed_cfb(), EVP_seed_cfb128(), EVP_seed_ecb(), EVP_seed_ofb() — this is the SEED encryption algorithm in CBC, CFB, ECB and OFB modes respectively. five functions, four modes, because cfb and cfb128 are both hanging out in the CFB lane. slay. 💅

---

⚠️ NOTES ⚠️

bestie, listen up, this part matters. 🫶 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-SEED(7) instead. see "Performance" in crypto(7) for further information.

not me warning you that spamming these calls is lowkey a performance L 😭 go fetch instead. the more you know. 🌈

---

🫶 RETURN VALUES 🫶

these functions return an EVP_CIPHER structure that contains the implementation of the symmetric cipher. that's your prize, bestie. go off. 👑

---

🔥 SEE ALSO 🔥

• evp(7)
• EVP_EncryptInit(3)

go read those too, iykyk. 📚✨

---

💜 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, bestie!! 🎀 this was OpenSSL 4.0.3, dated 2026-09-29, and it's EVP_SEED_CBC(3SSL) — main character energy from start to finish. no notes. periodt. 💅🌟🦋