ima_file_hash(9)

✨ ima_file_hash(9) — a Kernel API Manual moment ✨

okay so bestie, welcome to the Kernel API Manual 💖 this one is literally about ima_file_hash(9), and it’s giving “get the measurement of the file” energy. stay with me, it’s not scary fr fr 🫶

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🌸 NAME 🌸

ima_file_hash — return a measurement of the file ✨

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🦋 SYNOPSIS 🦋

int ima_file_hash (struct file *file , char *buf , size_t buf_size );

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🎀 ARGUMENTS 🎀

• file — pointer to the file 👀
• buf — buffer in which to store the hash 🧺
• buf_size — length of the buffer 📏

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💅 DESCRIPTION 💅

On success, return the hash algorithm (as defined in the enum hash_algo) 🔥 If buf is not NULL, this function also outputs the hash into buf. If the hash is larger than buf_size, then only buf_size bytes will be copied.

It generally just makes sense to pass a buffer capable of holding the largest possible hash: IMA_MAX_DIGEST_SIZE 💖 The file hash returned is based on the entire file, including the appended signature. no cap, the whole thing 🫶

If the measurement cannot be performed, return -EOPNOTSUPP 😭 If the parameters are incorrect, return -EINVAL 💀

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🌈 SEE ALSO 🌈

Kernel file ./security/integrity/ima/ima_main.c — and also, go say hi to these icons: ima_file_free(9), ima_file_mmap(9), ima_file_mprotect(9), ima_bprm_check(9), ima_creds_check(9), ima_bprm_creds_for_exec(9), ima_file_check(9), ima_inode_hash(9), ima_post_create_tmpfile(9), ima_post_path_mknod(9), ima_read_file(9), ima_post_read_file(9), ima_load_data(9), ima_post_load_data(9), process_buffer_measurement(9), ima_kexec_cmdline(9), ima_measure_critical_data(9), ima_measure_raw_policy(9), ima_kernel_module_request(9) ⭐

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xoxo 💅 source/version: ./security/integrity/ima · date: October 2026 · title: ima_file_hash(9) — periodt 🎀