crypto_cipher_blocksize(9)

✨ crypto_cipher_blocksize — like, how big is one block, bestie? ✨

okay so this is a page straight out of the Kernel API Manual (crypto_cipher_blocksize(9), section 9) and honestly it's a short one but it's iconic for what it does 💅

🌸 SYNOPSIS 🌸

unsigned int crypto_cipher_blocksize (struct crypto_cipher *tfm );

that's the whole vibe. one function, one handle, one answer 🎀

🦋 ARGUMENTS 🦋

• tfm — your cipher handle, aka the main character of this whole operation 👑

💖 DESCRIPTION 💖

so basically: you hand over the cipher handle tfm, and the function returns the block size for the single block cipher that handle references. that's it. that's the tea ☕

and why do you care? because the caller may use that information to allocate appropriate memory for the data returned by the encryption or decryption operation. like, you literally need to know how big the block is so you can make room for it — no cap, that's the whole point 🫶

⭐ RETURN ⭐

the block size of the cipher ✨ (an unsigned int, harmlessly sitting there being useful)

🔥 SEE ALSO 🔥

• Kernel file ./include/crypto/internal/cipher.h — the single block cipher filesystem friend 📁
• Single Block Cipher API(9)
• crypto_alloc_cipher(9)
• crypto_free_cipher(9)
• crypto_has_cipher(9)
• crypto_cipher_setkey(9)
• crypto_cipher_encrypt_one(9)
• crypto_cipher_decrypt_one(9)

like, the whole cipher squad, ily all 💜

and that's the page!! sign-off time 🧚 source: ./include/crypto/internal — dated October 2026 — filed under crypto_cipher_blocksize(9). slay, go read the other cipher manpages, mwah 💋🌈