BUF_reverse
BUF_reverse((unsigned char *)buf, NULL, i);
BUF_reverse(icv, NULL, 8);
BUF_reverse(out, NULL, inl - 16);
BUF_reverse(ctx->iv, iv, 8);
BUF_reverse(out, NULL, inl + 16);
void BUF_reverse(unsigned char *out, const unsigned char *in, size_t siz);
BUF_reverse(out, NULL, len);
BUF_reverse(icv, NULL, 8);
BUF_reverse(out, NULL, inl - 16);
BUF_reverse(ctx->iv, iv, 8);
BUF_reverse(sig, NULL, siglen);
BUF_reverse(gost_data, data, len);