1 /*
2 * BIP
3 * Copyright (c) 2010-2012, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "utils/includes.h"
10
11 #include "utils/common.h"
12 #include "common/ieee802_11_defs.h"
13 #include "crypto/aes_wrap.h"
14 #include "wlantest.h"
15
16
bip_protect(const u8 * igtk,size_t igtk_len,u8 * frame,size_t len,u8 * ipn,int keyid,size_t * prot_len)17 u8 * bip_protect(const u8 *igtk, size_t igtk_len, u8 *frame, size_t len,
18 u8 *ipn, int keyid, size_t *prot_len)
19 {
20 u8 *prot, *pos, *buf;
21 u8 mic[16];
22 u16 fc;
23 struct ieee80211_hdr *hdr;
24 size_t plen;
25
26 plen = len + (igtk_len == 32 ? 26 : 18);
27 prot = os_malloc(plen);
28 if (prot == NULL)
29 return NULL;
30 os_memcpy(prot, frame, len);
31 pos = prot + len;
32 *pos++ = WLAN_EID_MMIE;
33 *pos++ = igtk_len == 32 ? 24 : 16;
34 WPA_PUT_LE16(pos, keyid);
35 pos += 2;
36 os_memcpy(pos, ipn, 6);
37 pos += 6;
38 os_memset(pos, 0, igtk_len == 32 ? 16 : 8); /* MIC */
39
40 buf = os_malloc(plen + 20 - 24);
41 if (buf == NULL) {
42 os_free(prot);
43 return NULL;
44 }
45
46 /* BIP AAD: FC(masked) A1 A2 A3 */
47 hdr = (struct ieee80211_hdr *) frame;
48 fc = le_to_host16(hdr->frame_control);
49 fc &= ~(WLAN_FC_RETRY | WLAN_FC_PWRMGT | WLAN_FC_MOREDATA);
50 WPA_PUT_LE16(buf, fc);
51 os_memcpy(buf + 2, hdr->addr1, 3 * ETH_ALEN);
52 os_memcpy(buf + 20, prot + 24, plen - 24);
53 wpa_hexdump(MSG_MSGDUMP, "BIP: AAD|Body(masked)", buf, plen + 20 - 24);
54 /* MIC = L(AES-128-CMAC(AAD || Frame Body(masked)), 0, 64) */
55 if (omac1_aes_128(igtk, buf, plen + 20 - 24, mic) < 0) {
56 os_free(prot);
57 os_free(buf);
58 return NULL;
59 }
60 os_free(buf);
61
62 os_memcpy(pos, mic, igtk_len == 32 ? 16 : 8);
63 wpa_hexdump(MSG_DEBUG, "BIP MMIE MIC", pos, igtk_len == 32 ? 16 : 8);
64
65 *prot_len = plen;
66 return prot;
67 }
68
69
bip_gmac_protect(const u8 * igtk,size_t igtk_len,u8 * frame,size_t len,u8 * ipn,int keyid,size_t * prot_len)70 u8 * bip_gmac_protect(const u8 *igtk, size_t igtk_len, u8 *frame, size_t len,
71 u8 *ipn, int keyid, size_t *prot_len)
72 {
73 u8 *prot, *pos, *buf;
74 u16 fc;
75 struct ieee80211_hdr *hdr;
76 size_t plen;
77 u8 nonce[12], *npos;
78
79 plen = len + 26;
80 prot = os_malloc(plen);
81 if (prot == NULL)
82 return NULL;
83 os_memcpy(prot, frame, len);
84 pos = prot + len;
85 *pos++ = WLAN_EID_MMIE;
86 *pos++ = 24;
87 WPA_PUT_LE16(pos, keyid);
88 pos += 2;
89 os_memcpy(pos, ipn, 6);
90 pos += 6;
91 os_memset(pos, 0, 16); /* MIC */
92
93 buf = os_malloc(plen + 20 - 24);
94 if (buf == NULL) {
95 os_free(prot);
96 return NULL;
97 }
98
99 /* BIP AAD: FC(masked) A1 A2 A3 */
100 hdr = (struct ieee80211_hdr *) frame;
101 fc = le_to_host16(hdr->frame_control);
102 fc &= ~(WLAN_FC_RETRY | WLAN_FC_PWRMGT | WLAN_FC_MOREDATA);
103 WPA_PUT_LE16(buf, fc);
104 os_memcpy(buf + 2, hdr->addr1, 3 * ETH_ALEN);
105 os_memcpy(buf + 20, prot + 24, plen - 24);
106 wpa_hexdump(MSG_MSGDUMP, "BIP-GMAC: AAD|Body(masked)",
107 buf, plen + 20 - 24);
108
109 /* Nonce: A2 | IPN */
110 os_memcpy(nonce, hdr->addr2, ETH_ALEN);
111 npos = nonce + ETH_ALEN;
112 *npos++ = ipn[5];
113 *npos++ = ipn[4];
114 *npos++ = ipn[3];
115 *npos++ = ipn[2];
116 *npos++ = ipn[1];
117 *npos++ = ipn[0];
118 wpa_hexdump(MSG_EXCESSIVE, "BIP-GMAC: Nonce", nonce, sizeof(nonce));
119
120 /* MIC = AES-GMAC(AAD || Frame Body(masked)) */
121 if (aes_gmac(igtk, igtk_len, nonce, sizeof(nonce),
122 buf, plen + 20 - 24, pos) < 0) {
123 os_free(prot);
124 os_free(buf);
125 return NULL;
126 }
127 os_free(buf);
128
129 wpa_hexdump(MSG_DEBUG, "BIP-GMAC MMIE MIC", pos, 16);
130
131 *prot_len = plen;
132 return prot;
133 }
134
