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/* See LICENSE file for copyright and license details. */
#include "common.h"
/**
* Absorb the last part of the message and output a hash
*
* @param state The hashing state
* @param message The message, in bits
* @param msglen The length of the message, zero if there is nothing more to absorb
* @param output The output buffer for the hash
*/
void
libsha2_digest(struct libsha2_state *restrict state, const char *restrict message, size_t msglen, char *output)
{
char *appendix;
size_t i, j, k, n;
if (msglen & ~7) {
libsha2_update(state, message, msglen & ~7);
message += msglen & ~7;
msglen &= 7;
}
k = 8 * state->chunk_size;
n = state->chunk_size + 8;
n = (k + (n % k)) % k;
n = n / 8 - 1;
appendix = state->appendix;
if (msglen) {
j = 7 - msglen;
*appendix = *message;
*appendix |= 1 << j;
*appendix &= ~((1 << j) - 1);
} else {
*appendix = (unsigned char)128;
}
k = state->message_size + msglen;
i = state->chunk_size / 8;
appendix += n + i - 1;
for (i = i < sizeof(size_t) ? i : sizeof(size_t); i--;)
*(appendix - i) = (unsigned char)((k >> (i * 8)) & 255);
n += state->chunk_size;
libsha2_update(state, state->appendix, n);
n = libsha2_algorithm_output_size(state->algorithm);
switch (state->algorithm) {
case LIBSHA2_224:
case LIBSHA2_256:
for (i = 0; i < 8; i++)
for (j = 0; j < (state->chunk_size / 16); j++)
if (k = (i + 1) * (state->chunk_size / 16) - j - 1, k < n)
output[k] = (char)((state->h.b32[i] >> (8 * j)) & 255);
break;
default:
for (i = 0; i < 8; i++)
for (j = 0; j < (state->chunk_size / 16); j++)
if (k = (i + 1) * (state->chunk_size / 16) - j - 1, k < n)
output[k] = (char)((state->h.b64[i] >> (8 * j)) & 255);
break;
}
}
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