crypto_ror.c

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// SPDX-FileCopyrightText: 2016 pancake <pancake@nopcode.org>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_lib.h>
#include <rz_crypto.h>
#include <rz_util.h>
 
#define NAME "ror"
 
enum { MAX_ror_KEY_SIZE = 32768 };
 
struct ror_state {
    ut8 key[MAX_ror_KEY_SIZE];
    int key_size;
};
 
static bool ror_init_state(struct ror_state *const state, const ut8 *key, int keylen) {
    if (!state || !key || keylen < 1 || keylen > MAX_ror_KEY_SIZE) {
        return false;
    }
    int i;
    state->key_size = keylen;
    for (i = 0; i < keylen; i++) {
        state->key[i] = key[i];
    }
    return true;
}
 
static void ror_crypt(struct ror_state *const state, const ut8 *inbuf, ut8 *outbuf, int buflen) {
    int i;
    for (i = 0; i < buflen; i++) {
        ut8 count = state->key[i % state->key_size] & 7;
        ut8 inByte = inbuf[i];
        outbuf[i] = (inByte >> count) | (inByte << ((8 - count) & 7));
    }
}
 
static bool ror_set_key(RzCrypto *cry, const ut8 *key, int keylen, int mode, int direction) {
    rz_return_val_if_fail(cry->user && key, false);
    struct ror_state *st = (struct ror_state *)cry->user;
 
    cry->dir = direction;
    return ror_init_state(st, key, keylen);
}
 
static int ror_get_key_size(RzCrypto *cry) {
    rz_return_val_if_fail(cry->user, 0);
    struct ror_state *st = (struct ror_state *)cry->user;
 
    return st->key_size;
}
 
static bool ror_use(const char *algo) {
    return !strcmp(algo, NAME);
}
 
static bool update(RzCrypto *cry, const ut8 *buf, int len) {
    rz_return_val_if_fail(cry->user, false);
    struct ror_state *st = (struct ror_state *)cry->user;
 
    if (cry->dir) {
        eprintf("Use ROL algorithm to decrypt\n");
        return false;
    }
    ut8 *obuf = calloc(1, len);
    if (!obuf) {
        return false;
    }
    ror_crypt(st, buf, obuf, len);
    rz_crypto_append(cry, obuf, len);
    free(obuf);
    return true;
}
 
static bool ror_init(RzCrypto *cry) {
    rz_return_val_if_fail(cry, false);
 
    cry->user = RZ_NEW0(struct ror_state);
    return cry->user != NULL;
}
 
static bool ror_fini(RzCrypto *cry) {
    rz_return_val_if_fail(cry, false);
 
    free(cry->user);
    return true;
}
 
RzCryptoPlugin rz_crypto_plugin_ror = {
    .name = NAME,
    .author = "pancake",
    .license = "LGPL-3",
    .set_key = ror_set_key,
    .get_key_size = ror_get_key_size,
    .use = ror_use,
    .update = update,
    .final = update,
    .init = ror_init,
    .fini = ror_fini,
};
 
#ifndef RZ_PLUGIN_INCORE
RZ_API RzLibStruct rizin_plugin = {
    .type = RZ_LIB_TYPE_CRYPTO,
    .data = &rz_crypto_plugin_ror,
    .version = RZ_VERSION
};
#endif