ica_shake_256

Purpose

Performs a secure hash operation on the input data using the SHAKE-256 algorithm. Unlike other hash functions, the SHAKE algorithm has no fixed output length. This means that you can choose any output length which is a multiple of 8 bits (1 byte).

Format

unsigned int ica_shake_256(unsigned int message_part,
  uint64_t input_length,
  const unsigned char *input_data,
  shake_256_context_t *shake_256_context,
  unsigned char *output_data, unsigned int output_length);

Required hardware support

KIMD-SHAKE-256 and KLMD-SHAKE-256

Parameters

unsigned int message_part

The message chaining state. This parameter must be one of the following values:

SHA_MSG_PART_ONLY

a single hash operation.

SHA_MSG_PART_FIRST

the first part.

SHA_MSG_PART_MIDDLE

the middle part.

SHA_MSG_PART_FINAL

the last part.

uint64_t input_length

Length in bytes of the input data to be hashed using the SHAKE-256 algorithm. For SHA_MSG_PART_FIRST and SHA_MSG_PART_MIDDLE calls, the byte length must be a multiple of 136, that is, the SHAKE-256 block size.

const unsigned char *input_data

Pointer to the input data to be hashed. This pointer must not be zero. So even in case of zero size message data, it must be set to a valid value.

shake_256_context_t *shake_256_context

Pointer to the SHAKE-256 context structure used to store intermediate values needed when chaining is used. The contents are ignored for message part SHA_MSG_PART_ONLY and SHA_MSG_PART_FIRST. This structure must contain the returned value of the preceding call to ica_shake_256 for message part SHA_MSG_PART_MIDDLE and SHA_MSG_PART_FINAL. For message part SHA_MSG_PART_FIRST and SHA_MSG_PART_MIDDLE, the returned value can be used for a chained call of ica_shake_256. Therefore, the application must not modify the contents of this structure in between chained calls.

unsigned char *output_data

Pointer to the buffer to contain the resulting hash data. This pointer must be available and must not be NULL. The resulting output data has a length as returned in parameter output_length. Make sure that the buffer is at least this size.

unsigned int output_length

The resulting length of the hashed data. The output length must not be zero and must be 1 byte or more for all message parts.

Return codes

0

Success

For return codes indicating exceptions, see Return codes.