parity.c

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// SPDX-FileCopyrightText: 2021 deroad <wargio@libero.it>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include "parity.h"
#include <rz_util.h>
 
bool rz_parity_init(RzParity *ctx) {
    rz_return_val_if_fail(ctx, false);
    *ctx = 0;
    return true;
}
 
bool rz_parity_update(RzParity *ctx, const ut8 *data, size_t len) {
    rz_return_val_if_fail(ctx && data, false);
    ut32 ones = *ctx;
    for (size_t i = 0; i < len; ++i) {
        ut8 x = data[i];
        ones += ((x & 128) ? 1 : 0) + ((x & 64) ? 1 : 0) + ((x & 32) ? 1 : 0) + ((x & 16) ? 1 : 0) +
            ((x & 8) ? 1 : 0) + ((x & 4) ? 1 : 0) + ((x & 2) ? 1 : 0) + ((x & 1) ? 1 : 0);
    }
    *ctx = ones;
    return true;
}
 
bool rz_parity_final(ut8 *digest, RzParity *ctx) {
    rz_return_val_if_fail(digest && ctx, false);
    *digest = (*ctx) & 1;
    return true;
}