sm4_expandkey(9)

💖 sm4_expandkey(9) 💖

okay bestie, welcome to the sm4_expandkey(9) page from the Kernel API Manual — and it's literally all about expanding the SM4 key the way GB/T 32907-2016 says to do it. no cap 🫶

✨ NAME ✨

sm4_expandkey — expands the SM4 key as described in GB/T 32907-2016. 💅

🦋 SYNOPSIS 🦋

int sm4_expandkey (struct sm4_ctx *ctx , const u8 *in_key , unsigned int
      key_len );

💅 ARGUMENTS 💅

• ctx — the location where the computed key will be stored. 💖
• in_key — the supplied key. 🔑
• key_len — the length of the supplied key. 📏

🌸 DESCRIPTION 🌸

Returns 0 on success. ✨ The function fails only if an invalid key size (or pointer) is supplied. 😭

bestie, that's the fail vibe: invalid key size (or pointer), and that's it. 🫶

🎀 SEE ALSO 🎀

Also peek at the Kernel file ./include/crypto/sm4.h and sm4_crypt_block(9). 👀

xoxo bestie, this page came from ./include/crypto, dated October 2026 — stay slay and may your keys always expand correctly 💖✨