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API Reference

#./fio-stl/152 sha2z hkdf.h

5 public symbols.

#Macros

#FIO_HKDF_SHA256_HASH_LEN

c
#define FIO_HKDF_SHA256_HASH_LEN 32

SHA-256 hash length (32 bytes).

Symbol type: macro

#FIO_HKDF_SHA384_HASH_LEN

c
#define FIO_HKDF_SHA384_HASH_LEN 48

SHA-384 hash length (48 bytes).

Symbol type: macro

#Functions

#fio_hkdf_extract

c
void fio_hkdf_extract(void *restrict prk, const void *restrict salt, size_t salt_len, const void *restrict ikm, size_t ikm_len, int use_sha384)

HKDF-Extract: PRK = HMAC-Hash(salt, IKM)

Extracts a pseudorandom key (PRK) from input keying material (IKM).

Parameters:

  • prk - Output buffer (32 bytes for SHA-256, 48 for SHA-384)
  • salt - Optional salt (if NULL, uses zeros of hash length)
  • salt_len - Salt length in bytes
  • ikm - Input keying material
  • ikm_len - IKM length in bytes
  • use_sha384 - If non-zero, use SHA-384; otherwise SHA-256

Symbol type: function

#fio_hkdf_expand

c
void fio_hkdf_expand(void *restrict okm, size_t okm_len, const void *restrict prk, size_t prk_len, const void *restrict info, size_t info_len, int use_sha384)

HKDF-Expand: OKM = HKDF-Expand(PRK, info, L)

Expands a pseudorandom key (PRK) into output keying material (OKM).

Parameters:

  • okm - Output keying material buffer
  • okm_len - Desired output length (max 255 * hash_len)
  • prk - Pseudorandom key from Extract (32 or 48 bytes)
  • prk_len - PRK length (32 for SHA-256, 48 for SHA-384)
  • info - Optional context/application info
  • info_len - Info length in bytes
  • use_sha384 - If non-zero, use SHA-384; otherwise SHA-256

Symbol type: function

#fio_hkdf

c
void fio_hkdf(void *restrict okm, size_t okm_len, const void *restrict salt, size_t salt_len, const void *restrict ikm, size_t ikm_len, const void *restrict info, size_t info_len, int use_sha384)

Combined HKDF (Extract + Expand) - RFC 5869 Section 2.

Derives keying material from input keying material using HKDF.

Parameters:

  • okm - Output keying material buffer
  • okm_len - Desired output length (max 255 * hash_len)
  • salt - Optional salt (if NULL, uses zeros of hash length)
  • salt_len - Salt length in bytes
  • ikm - Input keying material
  • ikm_len - IKM length in bytes
  • info - Optional context/application info
  • info_len - Info length in bytes
  • use_sha384 - If non-zero, use SHA-384; otherwise SHA-256

Symbol type: function