path: root/libblake_blake2s_digest.c

/* See LICENSE file for copyright and license details. */
#include "common.h"

static void
encode_uint32_le(unsigned char *out, uint_least32_t value, size_t bytes)
{
	switch (bytes) {
	default:
		out[3] = (unsigned char)((value >> 24) & 255);
		/* fall through */
	case 3:
		out[2] = (unsigned char)((value >> 16) & 255);
		/* fall through */
	case 2:
		out[1] = (unsigned char)((value >>  8) & 255);
		/* fall through */
	case 1:
		out[0] = (unsigned char)((value >>  0) & 255);
		/* fall through */
	case 0:
		break;
	}
}

void
libblake_blake2s_digest(struct libblake_blake2s_state *state, void *data_, size_t len,
                        size_t output_len, unsigned char output[static output_len])
{
	unsigned char *data = data_;
	size_t r, i, j;

	r = libblake_blake2s_update(state, data, len);
	data = &data[r];
	len -= r;

	state->f[0] = UINT_LEAST32_C(0xFFFFffff);
	memset(&data[len], 0, 64 - len);

	state->t[0] = (state->t[0] + len) & UINT_LEAST32_C(0xFFFFffff);
	if (state->t[0] < len)
		state->t[1] = (state->t[1] + 1) & UINT_LEAST32_C(0xFFFFffff);

	libblake_internal_blake2s_compress(state, data);

	for (i = 0, j = 0; i < output_len; i += 4, j += 1)
		encode_uint32_le(&output[i], state->h[j], output_len - i);
}