_crypt_extended_init(void)
{
	int i, j, b, k, inbit, obit;
	uint32_t *p, *il, *ir, *fl, *fr;
	uint32_t *bits28, *bits24;
	u_char inv_key_perm[64];
	u_char u_key_perm[56];
	u_char inv_comp_perm[56];
	u_char init_perm[64], final_perm[64];
	u_char u_sbox[8][64];
	u_char un_pbox[32];

	bits24 = (bits28 = bits32 + 4) + 4;

	/*
	 * Invert the S-boxes, reordering the input bits.
	 */
	for (i = 0; i < 8; i++)
		for (j = 0; j < 64; j++) {
			b = (j & 0x20) | ((j & 1) << 4) | ((j >> 1) & 0xf);
			u_sbox[i][j] = sbox[i][b];
		}

	/*
	 * Convert the inverted S-boxes into 4 arrays of 8 bits.
	 * Each will handle 12 bits of the S-box input.
	 */
	for (b = 0; b < 4; b++)
		for (i = 0; i < 64; i++)
			for (j = 0; j < 64; j++)
				m_sbox[b][(i << 6) | j] =
					(u_sbox[(b << 1)][i] << 4) |
					u_sbox[(b << 1) + 1][j];

	/*
	 * Set up the initial & final permutations into a useful form, and
	 * initialise the inverted key permutation.
	 */
	for (i = 0; i < 64; i++) {
		init_perm[final_perm[i] = IP[i] - 1] = i;
		inv_key_perm[i] = 255;
	}

	/*
	 * Invert the key permutation and initialise the inverted key
	 * compression permutation.
	 */
	for (i = 0; i < 56; i++) {
		u_key_perm[i] = key_perm[i] - 1;
		inv_key_perm[key_perm[i] - 1] = i;
		inv_comp_perm[i] = 255;
	}

	/*
	 * Invert the key compression permutation.
	 */
	for (i = 0; i < 48; i++) {
		inv_comp_perm[comp_perm[i] - 1] = i;
	}

	/*
	 * Set up the OR-mask arrays for the initial and final permutations,
	 * and for the key initial and compression permutations.
	 */
	for (k = 0; k < 8; k++) {
		for (i = 0; i < 256; i++) {
			*(il = &ip_maskl[k][i]) = 0;
			*(ir = &ip_maskr[k][i]) = 0;
			*(fl = &fp_maskl[k][i]) = 0;
			*(fr = &fp_maskr[k][i]) = 0;
			for (j = 0; j < 8; j++) {
				inbit = 8 * k + j;
				if (i & bits8[j]) {
					if ((obit = init_perm[inbit]) < 32)
						*il |= bits32[obit];
					else
						*ir |= bits32[obit-32];
					if ((obit = final_perm[inbit]) < 32)
						*fl |= bits32[obit];
					else
						*fr |= bits32[obit - 32];
				}
			}
		}
		for (i = 0; i < 128; i++) {
			*(il = &key_perm_maskl[k][i]) = 0;
			*(ir = &key_perm_maskr[k][i]) = 0;
			for (j = 0; j < 7; j++) {
				inbit = 8 * k + j;
				if (i & bits8[j + 1]) {
					if ((obit = inv_key_perm[inbit]) == 255)
						continue;
					if (obit < 28)
						*il |= bits28[obit];
					else
						*ir |= bits28[obit - 28];
				}
			}
			*(il = &comp_maskl[k][i]) = 0;
			*(ir = &comp_maskr[k][i]) = 0;
			for (j = 0; j < 7; j++) {
				inbit = 7 * k + j;
				if (i & bits8[j + 1]) {
					if ((obit=inv_comp_perm[inbit]) == 255)
						continue;
					if (obit < 24)
						*il |= bits24[obit];
					else
						*ir |= bits24[obit - 24];
				}
			}
		}
	}

	/*
	 * Invert the P-box permutation, and convert into OR-masks for
	 * handling the output of the S-box arrays setup above.
	 */
	for (i = 0; i < 32; i++)
		un_pbox[pbox[i] - 1] = i;

	for (b = 0; b < 4; b++)
		for (i = 0; i < 256; i++) {
			*(p = &psbox[b][i]) = 0;
			for (j = 0; j < 8; j++) {
				if (i & bits8[j])
					*p |= bits32[un_pbox[8 * b + j]];
			}
		}
}

This weakness pertains to the use of cryptographic functions that are weak, misconfigured, or outdated, which undermines the intended protection of encrypted data and communications.