STRUCT ECRYPTFS_KEY_TFM(9)

💖 NAME 💖

struct ecryptfs_key_tfm — the Persistent key tfm, aka the crypto handle that just stays around 💅

✨ SYNOPSIS ✨

okay so picture the vibes, here's the whole struct bestie:

struct ecryptfs_key_tfm {
    struct crypto_skcipher *key_tfm;
    size_t key_size;
    struct mutex key_tfm_mutex;
    struct list_head key_tfm_list;
    unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
 };

🎀 Members 🎀

• key_tfm — the crypto API handle to the key, it's giving main character energy 🔥
• key_size — how big the key is, in bytes
• key_tfm_mutex — a mutex so that literally only one operation in eCryptfs is using the persistent TFM at any point in time. no sharing, no chaos, one at a time periodt 🔒
• key_tfm_list — the handle that hangs this whole thing off the module-wide TFM list 🧵
• cipher_name — string name for the cipher for this TFM, iconic ✨

🦋 Description 🦋

so the tea is: typically eCryptfs will use the same ciphers over and over again throughout the course of its operations. and like… re-initializing the same cipher every single time? exhausting. unnecessary. so to avoid unnecessarily destroying and initializing the same cipher repeatedly, eCryptfs keeps a list of crypto API contexts around to use when needed 🫶

it's literally a little crypto wardrobe. why rebuild the fit every time when you can just keep it on rotation 💅

🌸 SEE ALSO 🌸

• Kernel file ./fs/ecryptfs/ecryptfs_kernel.h struct ecryptfs_global_auth_tok(9) 👀

and that's the page bestie!! source is ./fs/ecryptfs, dated October 2026, all about struct ecryptfs_key_tfm(9) — go read it again, slay 💜🎀✨