KangarooTwelve

Faster, reduced-round XOF with a customzation string, as defined in the draft KangarooTwelve and TurboSHAKE specification. More...

Data Structures
struct	k12_t
	KangarooTwelve XOF context (all members are private). More...

Functions
void	k12_once (const uint8_t *src, const size_t src_len, uint8_t *dst, const size_t dst_len)
	Absorb data into KangarooTwelve, then squeeze bytes out. More...
void	k12_custom_once (const uint8_t *src, const size_t src_len, const uint8_t *custom, const size_t custom_len, uint8_t *dst, const size_t dst_len)
	Absorb data into KangarooTwelve with customization string, then squeeze bytes out. More...
void	k12_init (k12_t *k12, const uint8_t *src, const size_t src_len, const uint8_t *custom, const size_t custom_len)
	Initialize KangarooTwelve context. More...
void	k12_squeeze (k12_t *k12, uint8_t *dst, const size_t len)
	Squeeze bytes from KangarooTwelve context. More...

Detailed Description

Faster, reduced-round XOF with a customzation string, as defined in the draft KangarooTwelve and TurboSHAKE specification.

Function Documentation

k12_custom_once()

void k12_custom_once	(	const uint8_t *	src,
		const size_t	src_len,
		const uint8_t *	custom,
		const size_t	custom_len,
		uint8_t *	dst,
		const size_t	dst_len
	)

Absorb data into KangarooTwelve with customization string, then squeeze bytes out.

Initialize internal KangarooTwelve context with custom string custom of length custom_len, absorb src_len bytes of input from source buffer src, then squeeze dst_len bytes of output into destination buffer dst.

Parameters

[in]	src	Source buffer.
[in]	src_len	Source buffer length, in bytes.
[in]	custom	Custom string buffer.
[in]	custom_len	Custom string length, in bytes.
[out]	dst	Destination buffer.
[in]	dst_len	Destination buffer length, in bytes.

Example:

  // get 1024 random bytes
  uint8_t buf[1024] = { 0 };
  rand_bytes(buf, sizeof(buf));
 
  // customization string and length (in bytes, w/o NUL)
  const uint8_t custom[] = "hello";
  const size_t custom_len = sizeof(custom) - 1;
 
  // absorb `buf` and `custom` into KangarooTwelve, write 32 bytes to
  // `out`
  uint8_t out[32] = { 0 };
  k12_custom_once(buf, sizeof(buf), custom, custom_len, out, sizeof(out));

k12_init()

void k12_init	(	k12_t *	k12,
		const uint8_t *	src,
		const size_t	src_len,
		const uint8_t *	custom,
		const size_t	custom_len
	)

Initialize KangarooTwelve context.

Initialize KangarooTwelve context with message src of length src_len bytes and custom string custom of length custom_len bytes.

Note

This KangarooTwelve implementation is sequential, not parallel.

Parameters

[out]	k12	KangarooTwelve context.
[in]	src	Source buffer.
[in]	src_len	Source buffer length, in bytes.
[in]	custom	Custom string buffer.
[in]	custom_len	Custom string length, in bytes.

Example:

  // get 1024 random bytes
  uint8_t buf[1024] = { 0 };
  rand_bytes(buf, sizeof(buf));
 
  // customization string and length (in bytes, w/o NUL)
  const uint8_t custom[] = "hello";
  const size_t custom_len = sizeof(custom) - 1;
 
  // create KangarooTwelve context from `buf and `custom`
  k12_t ctx = { 0 };
  k12_init(&ctx, buf, sizeof(buf), custom, custom_len);
 
  // print result prefix to stdout
  printf("%s: ", __func__);
 
  // squeeze first 128 bytes of of result in 32 byte chunks
  for (size_t i = 0; i < 128; i += 32) {
    // squeeze 32 bytes of result into `out`
    uint8_t out[32] = { 0 };
    k12_squeeze(&ctx, out, sizeof(out));
 
    // encode as hex, print to stdout
    hex_write(stdout, out, sizeof(out));
  }
 
  // print result suffix to stdout
  fputs("\n", stdout);

k12_once()

void k12_once	(	const uint8_t *	src,
		const size_t	src_len,
		uint8_t *	dst,
		const size_t	dst_len
	)

Absorb data into KangarooTwelve, then squeeze bytes out.

Initialize internal KangarooTwelve context, absorb src_len bytes of input from source buffer src, then squeeze dst_len bytes of output into destination buffer dst.

Parameters

[in]	src	Source buffer.
[in]	src_len	Source buffer length, in bytes.
[out]	dst	Destination buffer.
[in]	dst_len	Destination buffer length, in bytes.

Example:

  // get 1024 random bytes
  uint8_t buf[1024] = { 0 };
  rand_bytes(buf, sizeof(buf));
 
  // absorb `buf` into KangarooTwelve, write 32 bytes to `out`
  uint8_t out[32] = { 0 };
  k12_once(buf, sizeof(buf), out, sizeof(out));

k12_squeeze()

void k12_squeeze	(	k12_t *	k12,
		uint8_t *	dst,
		const size_t	len
	)

Squeeze bytes from KangarooTwelve context.

Squeeze dst_len bytes of output into destination buffer dst from KangarooTwelve context k12. Can be called iteratively to squeeze output data in chunks.

Note

This KangarooTwelve implementation is sequential, not parallel.

Parameters

[in,out]	k12	KangarooTwelve context.
[out]	dst	Destination buffer.
[in]	len	Destination buffer length, in bytes.

Example:

  // get 1024 random bytes
  uint8_t buf[1024] = { 0 };
  rand_bytes(buf, sizeof(buf));
 
  // customization string and length (in bytes, w/o NUL)
  const uint8_t custom[] = "hello";
  const size_t custom_len = sizeof(custom) - 1;
 
  // create KangarooTwelve context from `buf and `custom`
  k12_t ctx = { 0 };
  k12_init(&ctx, buf, sizeof(buf), custom, custom_len);
 
  // print result prefix to stdout
  printf("%s: ", __func__);
 
  // squeeze first 128 bytes of of result in 32 byte chunks
  for (size_t i = 0; i < 128; i += 32) {
    // squeeze 32 bytes of result into `out`
    uint8_t out[32] = { 0 };
    k12_squeeze(&ctx, out, sizeof(out));
 
    // encode as hex, print to stdout
    hex_write(stdout, out, sizeof(out));
  }
 
  // print result suffix to stdout
  fputs("\n", stdout);