KCAPI_AKCIPHER_ENCRY(3)

💖 KCAPI_AKCIPHER_ENCRY 💖

okay bestie, welcome to the libkcapi girlies' corner of section 3 — this one lives in the Programming Interface manual and it's literally the moment you've been waiting for 🫶

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✨ NAME ✨

kcapi_akcipher_encrypt_aio — encrypt data (asynchronous one shot) 🔐✨

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🌸 SYNOPSIS 🌸

ssize_t kcapi_akcipher_encrypt_aio(struct kcapi_handle * handle,
                                   struct iovec * iniov,
                                   struct iovec * outiov, size_t iovlen,
                                   int access);

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🎀 ARGUMENTS 🎀

• handle — [in] your cipher handle, the main character of this whole operation 👑
• iniov — [in] head of the scatter-gather list array holding the plaintext (this is the tea you're about to encrypt 🍓)
• outiov — [out] head of the scatter-gather list of the destination buffers, which get filled with ciphertext 💜
• iovlen — [in] number of scatter-gather list entries (how many lil chunks we're working with)
• access — [in] kernel access type, and babes you have options:
  • KCAPI_ACCESS_HEURISTIC — use internal heuristic for fastest kernel access ⚡
  • KCAPI_ACCESS_VMSPLICE — use vmsplice access
  • KCAPI_ACCESS_SENDMSG — sendmsg access

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🦋 DESCRIPTION 🦋

so here's the vibe: the individual scatter-gather list entries are processed with separate invocations of the the given cipher. like, each one gets its own moment, no sharing ✨

now the memory part, and listen closely because this one matters — the memory should be aligned at the page boundary using posix_memalign(sysconf(_SC_PAGESIZE)). if it is not aligned at the page boundary, the vmsplice call may not send all data to the kernel 😭 no cap, that's just how it is.

⚠️ fr fr, get that alignment right or the kernel might not receive everything. it's giving "missing data" and nobody wants that.

and the return value? number of bytes encrypted upon success 🎉 — or a negative errno-style error code if an error occurred 💀

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🌈 AUTHOR 🌈

Stephan Mueller <smueller@chronox.de> Author. 💅

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👑 COPYRIGHT 👑

that's the whole page, bestie — no more sections, no less. 🧚

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and that's a wrap on this one, gorgeous 🌸 the source is the libkcapi Manual, version 1.5.0, dated July 2025 — so you know exactly which era of the manual you're reading. go forth and encrypt responsibly, mwah 💖✨