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/* See LICENSE file for copyright and license details. */
#include "common.h"
/**
* Absorb more, or the first part, of the message
* and wipe sensitive data when possible
*
* @param state The hashing state
* @param msg The partial message
* @param msglen The length of the partial message, in bytes
* @return Zero on success, -1 on error
*/
int
libkeccak_hmac_update(struct libkeccak_hmac_state *restrict state, const void *restrict msg_, size_t msglen)
{
const char *restrict msg = msg_;
size_t i;
int n, cn, r;
if (state->key_ipad) {
if (libkeccak_update(&state->sponge, state->key_ipad, state->key_length >> 3) < 0)
return -1;
if (state->key_length & 7)
state->leftover = state->key_ipad[state->key_length >> 3];
state->key_ipad = NULL;
}
if (!msg || !msglen)
return 0;
if (!(state->key_length & 7))
return libkeccak_update(&state->sponge, msg, msglen);
if (msglen != state->buffer_size) {
free(state->buffer);
state->buffer = malloc(state->buffer_size = msglen);
if (!state->buffer)
return -1;
}
n = (int)(state->key_length & 7);
cn = 8 - n;
for (i = 1; i < msglen; i++)
state->buffer[i] = (char)(((unsigned char)msg[i - 1] >> cn) | (msg[i] << n));
state->buffer[0] = (char)((state->leftover & ((1 << n) - 1)) | (msg[0] << n));
state->leftover = (char)((unsigned char)msg[msglen - 1] >> cn);
r = libkeccak_update(&state->sponge, state->buffer, msglen);
my_explicit_bzero(state->buffer, msglen);
return r;
}
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