Merged the hostap_2.6 updates, and the Leap of Faith work, from the hostap_update...

[mech_eap.git] / libeap / wlantest / wep.c

diff --git a/libeap/wlantest/wep.c b/libeap/wlantest/wep.c
new file mode 100644 (file)
index 0000000..c4137f3
--- /dev/null
+++ b/libeap/wlantest/wep.c
@@ -0,0 +1,103 @@
+/*
+ * Wired Equivalent Privacy (WEP)
+ * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include "utils/includes.h"
+
+#include "utils/common.h"
+#include "common/ieee802_11_defs.h"
+#include "wlantest.h"
+
+
+void wep_crypt(u8 *key, u8 *buf, size_t plen)
+{
+       u32 i, j, k;
+       u8 S[256];
+#define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
+       u8 *pos;
+
+       /* Setup RC4 state */
+       for (i = 0; i < 256; i++)
+               S[i] = i;
+       j = 0;
+       for (i = 0; i < 256; i++) {
+               j = (j + S[i] + key[i & 0x0f]) & 0xff;
+               S_SWAP(i, j);
+       }
+
+       /* Apply RC4 to data */
+       pos = buf;
+       i = j = 0;
+       for (k = 0; k < plen; k++) {
+               i = (i + 1) & 0xff;
+               j = (j + S[i]) & 0xff;
+               S_SWAP(i, j);
+               *pos ^= S[(S[i] + S[j]) & 0xff];
+               pos++;
+       }
+}
+
+
+static int try_wep(const u8 *key, size_t key_len, const u8 *data,
+                  size_t data_len, u8 *plain)
+{
+       u32 icv, rx_icv;
+       u8 k[16];
+       int i, j;
+
+       for (i = 0, j = 0; i < sizeof(k); i++) {
+               k[i] = key[j];
+               j++;
+               if (j >= key_len)
+                       j = 0;
+       }
+
+       os_memcpy(plain, data, data_len);
+       wep_crypt(k, plain, data_len);
+       icv = crc32(plain, data_len - 4);
+       rx_icv = WPA_GET_LE32(plain + data_len - 4);
+       if (icv != rx_icv)
+               return -1;
+
+       return 0;
+}
+
+
+u8 * wep_decrypt(struct wlantest *wt, const struct ieee80211_hdr *hdr,
+                const u8 *data, size_t data_len, size_t *decrypted_len)
+{
+       u8 *plain;
+       struct wlantest_wep *w;
+       int found = 0;
+       u8 key[16];
+
+       if (dl_list_empty(&wt->wep))
+               return NULL;
+
+       if (data_len < 4 + 4)
+               return NULL;
+       plain = os_malloc(data_len - 4);
+       if (plain == NULL)
+               return NULL;
+
+       dl_list_for_each(w, &wt->wep, struct wlantest_wep, list) {
+               os_memcpy(key, data, 3);
+               os_memcpy(key + 3, w->key, w->key_len);
+               if (try_wep(key, 3 + w->key_len, data + 4, data_len - 4, plain)
+                   == 0) {
+                       found = 1;
+                       break;
+               }
+       }
+       if (!found) {
+               os_free(plain);
+               return NULL;
+       }
+
+       *decrypted_len = data_len - 4 - 4;
+       return plain;
+}