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/**
* libkeccak – Keccak-family hashing library
*
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "state.h"
#include <string.h>
/**
* Initialise a state according to hashing specifications
*
* @param state The state that should be initialised
* @param spec The specifications for the state
* @return Zero on success, -1 on error
*/
int libkeccak_state_initialise(libkeccak_state_t* restrict state, const libkeccak_spec_t* restrict spec)
{
long x;
state->r = spec->bitrate;
state->n = spec->output;
state->c = spec->capacity;
state->b = state->r + state->c;
state->w = x = state->b / 25;
state->l = 0;
if (x & 0xF0L) state->l |= 4, x >>= 4;
if (x & 0x0CL) state->l |= 2, x >>= 2;
if (x & 0x02L) state->l |= 1;
state->nr = 12 + (state->l << 1);
state->wmod = (state->w == 64) ? ~0LL : (int_fast64_t)((1ULL << state->w) - 1);
for (x = 0; x < 25; x++)
state->S[x] = 0;
state->mptr = 0;
state->mlen = (size_t)(state->r * state->b) >> 2;
state->M = malloc(state->mlen * sizeof(char));
return state->M == NULL ? -1 : 0;
}
/**
* Wipe data in the state's message wihout freeing any data
*
* @param state The state that should be wipe
*/
void libkeccak_state_wipe_message(volatile libkeccak_state_t* restrict state)
{
volatile char* restrict M = state->M;
size_t i;
for (i = 0; i < state->mptr; i++)
M[i] = 0;
}
/**
* Wipe data in the state's sponge wihout freeing any data
*
* @param state The state that should be wipe
*/
void libkeccak_state_wipe_sponge(volatile libkeccak_state_t* restrict state)
{
volatile int_fast64_t* restrict S = state->S;
size_t i;
for (i = 0; i < 25; i++)
S[i] = 0;
}
/**
* Wipe sensitive data wihout freeing any data
*
* @param state The state that should be wipe
*/
void libkeccak_state_wipe(volatile libkeccak_state_t* restrict state)
{
libkeccak_state_wipe_message(state);
libkeccak_state_wipe_sponge(state);
}
/**
* Make a copy of a state
*
* @param dest The slot for the duplicate, must not be initialised (memory leak otherwise)
* @param src The state to duplicate
* @return Zero on success, -1 on error
*/
int libkeccak_state_copy(libkeccak_state_t* restrict dest, const libkeccak_state_t* restrict src)
{
memcpy(dest, src, sizeof(libkeccak_state_t));
dest->M = malloc(src->mlen * sizeof(char));
if (dest->M == NULL)
return -1;
memcpy(dest->M, src->M, src->mptr * sizeof(char));
return 0;
}
/**
* Marshal a `libkeccak_state_t` into a buffer
*
* @param state The state to marshal
* @param data The output buffer
* @return The number of bytes stored to `data`
*/
size_t libkeccak_state_marshal(const libkeccak_state_t* restrict state, char* restrict data)
{
#define set(type, var) *((type*)data) = state->var, data += sizeof(type) / sizeof(char)
set(long, r);
set(long, c);
set(long, n);
set(long, b);
set(long, w);
set(int_fast64_t, wmod);
set(long, l);
set(long, nr);
memcpy(data, state->S, sizeof(state->S));
data += sizeof(state->S) / sizeof(char);
set(size_t, mptr);
set(size_t, mlen);
memcpy(data, state->M, state->mptr * sizeof(char));
data += state->mptr;
return sizeof(libkeccak_state_t) - sizeof(char*) + state->mptr * sizeof(char);
#undef set
}
/**
* Unmarshal a `libkeccak_state_t` from a buffer
*
* @param state The slot for the unmarshalled state, must not be initialised (memory leak otherwise)
* @param data The input buffer
* @return The number of bytes read from `data`, 0 on error
*/
size_t libkeccak_state_unmarshal(libkeccak_state_t* restrict state, const char* restrict data)
{
#define get(type, var) state->var = *((const type*)data), data += sizeof(type) / sizeof(char)
get(long, r);
get(long, c);
get(long, n);
get(long, b);
get(long, w);
get(int_fast64_t, wmod);
get(long, l);
get(long, nr);
memcpy(state->S, data, sizeof(state->S));
data += sizeof(state->S) / sizeof(char);
get(size_t, mptr);
get(size_t, mlen);
state->M = malloc(state->mptr * sizeof(char));
if (state->M == NULL)
return 0;
memcpy(state->M, data, state->mptr * sizeof(char));
data += state->mptr;
return sizeof(libkeccak_state_t) - sizeof(char*) + state->mptr * sizeof(char);
#undef get
}
/**
* Gets the number of bytes the `libkeccak_state_t` stored
* at the beginning of `data` occupies
*
* @param data The data buffer
* @return The byte size of the stored state
*/
size_t libkeccak_state_unmarshal_skip(const char* restrict data)
{
data += (7 * sizeof(long) + 26 * sizeof(int_fast64_t)) / sizeof(char);
return sizeof(libkeccak_state_t) - sizeof(char*) + *(const size_t*)data * sizeof(char);
}
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