cSHAKE

cSHAKE variants of the SHA3 algorithms, with variable output lengths. More...

Files
file	ocrypto_cshake.h
	cSHAKE variants of the SHA3 algorithms, with variable output lengths.

Functions
void	ocrypto_cshake128 (uint8_t *r, size_t r_len, const uint8_t *in, size_t in_len, const uint8_t *n, size_t n_len, const uint8_t *s, size_t s_len)
void	ocrypto_cshake256 (uint8_t *r, size_t r_len, const uint8_t *in, size_t in_len, const uint8_t *n, size_t n_len, const uint8_t *s, size_t s_len)

Incremental cSHAKE generator
This group of functions can be used to incrementally compute the cSHAKE hash for a given input.
void	ocrypto_cshake128_init (ocrypto_cshake_ctx *ctx, const uint8_t *n, size_t n_len, const uint8_t *s, size_t s_len)
void	ocrypto_cshake256_init (ocrypto_cshake_ctx *ctx, const uint8_t *n, size_t n_len, const uint8_t *s, size_t s_len)
void	ocrypto_cshake128_update (ocrypto_cshake_ctx *ctx, const uint8_t *in, size_t in_len)
void	ocrypto_cshake256_update (ocrypto_cshake_ctx *ctx, const uint8_t *in, size_t in_len)
void	ocrypto_cshake128_final (ocrypto_cshake_ctx *ctx, uint8_t *r, size_t r_len)
void	ocrypto_cshake256_final (ocrypto_cshake_ctx *ctx, uint8_t *r, size_t r_len)
void	ocrypto_cshake128_ext (ocrypto_cshake_ctx *ctx, uint8_t *r, size_t r_len)
void	ocrypto_cshake256_ext (ocrypto_cshake_ctx *ctx, uint8_t *r, size_t r_len)

Detailed Description

cSHAKE variants of the SHA3 algorithms, with variable output lengths.

The cSHAKE family is a variable output variant of the SHA3 hash functions with additional inputs, with 128 and 256 bit security.

A fixed-sized message digest is computed from variable length input data, a function name, and a customization string. The function is practically impossible to revert, and small changes in the input message lead to major changes in the message digest.

See also

FIPS - SHA-3 Standard: Permutation-Based Hash and Extendable-Output Functions

NIST - SHA-3 Derived Functions: cSHAKE, KMAC, TupleHash and ParallelHash