ecryptfs_enc...ode_filename(9)

💅 ecryptfs_encrypt_and_encode_filename — Kernel API Manual, bestie edition ✨

okay so real talk, this is a page from the Kernel API Manual (the header up top is literally ecryptfs_enc...ode_filename(9) — yes the title got squished and truncated, we love a dramatic ellipsis 💀) and it's all about turning a cute little plaintext filename into cryptographic confetti. let's get into it 🎀

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✨ NAME ✨

ecryptfs_encrypt_and_encode_filename — converts a plaintext file name to cipher text 🔐

like, it takes your readable name and makes it unreadable. glow-up via encryption, no cap.

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🌸 SYNOPSIS 🌸

int ecryptfs_encrypt_and_encode_filename (char **encoded_name , size_t
*encoded_name_size , struct ecryptfs_mount_crypt_stat *mount_crypt_stat
, const char *name , size_t name_size );

that's the whole signature, character for character, don't @ me 🫶

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🦋 ARGUMENTS 🦋

• encoded_name — the encrypted name 💖 the function hands it back to you through this pointer-to-pointer, so it's giving main character energy.
• encoded_name_size — the length of the encrypted name 📏 (yes, you gotta track the size, it's that kind of relationship).
• mount_crypt_stat — the crypt_stat struct associated with the file name to encode 🗂️ it's the struct that's tied to the name you're encoding.
• name — the plaintext name 🌼 your innocent, readable, pre-glow-up filename.
• name_size — the length of the plaintext name ✨ keep it exact bestie.

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💜 DESCRIPTION 💜

So what it does: it encrypts and encodes a filename into something that constitutes a valid filename for a filesystem, using printable characters 🔥

which is lowkey the whole point — filesystems are picky about what characters they'll accept, so this thing makes sure the encrypted output is all printable and legal. iconic behavior, honestly 👑

We assume that we have a properly initialized crypto context, pointed to by crypt_stat->tfm 🧚 so like… don't come in here with an uninitialized context, that's not the vibe.

Returns zero on success; non-zero on otherwise ⭐ that's it, that's the return value contract. zero = slay, non-zero = something went sideways 😭

⚠️ heads up: the properly-initialized crypto context pointed to by crypt_stat->tfm is an assumption, not something this function checks for you. read the room (and the code) before calling.

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🌈 SEE ALSO 🌈

Kernel file ./fs/ecryptfs/crypto.c — and the whole friend group of related functions, all (9)s, all here, no gatekeeping:

• ecryptfs_from_hex(9)
• ecryptfs_derive_iv(9)
• ecryptfs_init_crypt_stat(9)
• ecryptfs_destroy_crypt_stat(9)
• virt_to_scatterlist(9)
• crypt_scatterlist(9)
• crypt_extent(9)
• ecryptfs_encrypt_page(9)
• ecryptfs_decrypt_page(9)
• ecryptfs_init_crypt_ctx(9)
• ecryptfs_copy_mount_wide_flags_to_inode_flags(9)
• ecryptfs_set_default_crypt_stat_vals(9)
• ecryptfs_new_file_context(9)
• ecryptfs_validate_marker(9)
• ecryptfs_process_flags(9)
• write_ecryptfs_marker(9)
• ecryptfs_code_for_cipher_string(9)
• ecryptfs_cipher_code_to_string(9)
• ecryptfs_write_headers_virt(9)
• ecryptfs_write_metadata(9)
• set_default_header_data(9)
• ecryptfs_read_headers_virt(9)
• ecryptfs_read_xattr_region(9)
• ecryptfs_process_key_cipher(9)
• ecryptfs_destroy_crypto(9)
• ecryptfs_tfm_exists(9)
• ecryptfs_get_tfm_and_mutex_for_cipher_name(9)
• ecryptfs_encode_for_filename(9)
• ecryptfs_decode_from_filename(9)
• ecryptfs_decode_and_decrypt_filename(9)

like I said — full friend group, all invited to the function party 🎉

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and that's the page, bestie 🫶 this one came out of ./fs/ecryptfs in October 2026, filed under the very dramatically truncated name ecryptfs_enc...ode_filename(9). go encrypt something. periodt 💅✨