alpine 3.6
crypto weakness #60

4

Weakness Breakdown


Definition:

This weakness involves creating non-standard or non-tested algorithms, using weak algorithms or applying cryptographic algorithms incorrectly. Algorithms that were once considered safe are commonly later found to be unsafe, as the algorithms were broken.

Warning code(s):

The crypt functions use a poor one-way hashing algorithm; since they only accept passwords of 8 characters or fewer and only a two-byte salt, they are excessively vulnerable to dictionary attacks given today's faster computing equipment.

File Name:

wpa_supplicant/src/wpa_supplicant-2.6/src/ap/wpa_auth_ft.c

Context:

The highlighted line of code below is the trigger point of this particular Alpine 3.6 crypto weakness.

 
	if (data_len < sizeof(f))
		return -1;

	r1kh = wpa_auth->conf.r1kh_list;
	while (r1kh) {
		if (os_memcmp(r1kh->addr, src_addr, ETH_ALEN) == 0)
			break;
		r1kh = r1kh->next;
	}
	if (r1kh == NULL) {
		wpa_printf(MSG_DEBUG, "FT: No matching R1KH address found for "
			   "PMK-R1 pull source address " MACSTR,
			   MAC2STR(src_addr));
		return -1;
	}

	crypt = data + offsetof(struct ft_r0kh_r1kh_pull_frame, nonce);
	os_memset(&f, 0, sizeof(f));
	plain = ((u8 *) &f) + offsetof(struct ft_r0kh_r1kh_pull_frame, nonce);
	/* aes_unwrap() does not support inplace decryption, so use a temporary
	 * buffer for the data. */
	if (aes_unwrap(r1kh->key, sizeof(r1kh->key),
		       (FT_R0KH_R1KH_PULL_DATA_LEN + 7) / 8,
		       crypt, plain) < 0) {
		wpa_printf(MSG_DEBUG, "FT: Failed to decrypt PMK-R1 pull "
			   "request from " MACSTR, MAC2STR(src_addr));
		return -1;
	}

	wpa_hexdump(MSG_DEBUG, "FT: PMK-R1 pull - nonce",
		    f.nonce, sizeof(f.nonce));
	wpa_hexdump(MSG_DEBUG, "FT: PMK-R1 pull - PMKR0Name",
		    f.pmk_r0_name, WPA_PMK_NAME_LEN);
	wpa_printf(MSG_DEBUG, "FT: PMK-R1 pull - R1KH-ID=" MACSTR " S1KH-ID="
		   MACSTR, MAC2STR(f.r1kh_id), MAC2STR(f.s1kh_id));

	os_memset(&resp, 0, sizeof(resp));
	resp.frame_type = RSN_REMOTE_FRAME_TYPE_FT_RRB;
	resp.packet_type = FT_PACKET_R0KH_R1KH_RESP;
	resp.data_length = host_to_le16(FT_R0KH_R1KH_RESP_DATA_LEN);
	os_memcpy(resp.ap_address, wpa_auth->addr, ETH_ALEN);

	/* aes_wrap() does not support inplace encryption, so use a temporary
	 * buffer for the data. */
	os_memcpy(r.nonce, f.nonce, sizeof(f.nonce));
	os_memcpy(r.r1kh_id, f.r1kh_id, FT_R1KH_ID_LEN);
	os_memcpy(r.s1kh_id, f.s1kh_id, ETH_ALEN);
	if (wpa_ft_fetch_pmk_r0(wpa_auth, f.s1kh_id, f.pmk_r0_name, pmk_r0,
				&pairwise) < 0) { 

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