---
name: "libkeccak_cshake_suffix"
section: "3"
platform: "linux"
package: "libkeccak"
version: "1.4.3-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/libkeccak_cshake_suffix"
---

# libkeccak\_cshake\_suffix(3)

Get message suffix for cSHAKE hashing

## NAME

libkeccak\_cshake\_suffix - Get message suffix for cSHAKE hashing

## SYNOPSIS

```
#include <libkeccak.h>
const char *libkeccak_cshake_suffix(size_t nlen, size_t slen);
```

Link with *-lkeccak*.

## DESCRIPTION

The **libkeccak\_cshake\_suffix**() function returns a string of '1':s and '0':s representing the bits the the message suffixed that shall be used. Canonically, the values of the *nlen* and *slen* parameters shall be the length of the cSHAKE function-name bit-string and the cSHAKE customisation bit-string, however, the function will only check whether these values are zero or non-zero.

## RETURN VALUES

The **libkeccak\_cshake\_suffix**() function returns a statically allocated, read-only, message suffix bit-string that shall be used.

## ERRORS

The **libkeccak\_cshake\_suffix**() function cannot fail.

## SEE ALSO

[**libkeccak\_spec\_cshake**(3)](/libkeccak_spec_cshake/3.md), [**libkeccak\_generalised\_spec\_initialise**(3)](/libkeccak_generalised_spec_initialise/3.md), [**libkeccak\_state\_initialise**(3)](/libkeccak_state_initialise/3.md), [**libkeccak\_cshake\_initialise**(3)](/libkeccak_cshake_initialise/3.md), [**libkeccak\_fast\_digest**(3)](/libkeccak_fast_digest/3.md), [**libkeccak\_zerocopy\_digest**(3)](/libkeccak_zerocopy_digest/3.md), [**libkeccak\_digest**(3)](/libkeccak_digest/3.md)