Airkiss: add aes-cbc-128 decryption

Makefile

@@ -1,7 +1,7 @@
 ELF = airkiss
 SRCS = main.c 
 SRCS += capture/common.c capture/osdep.c capture/linux.c capture/radiotap/radiotap-parser.c
-SRCS += utils/wifi_scan.c airkiss.c
+SRCS += utils/wifi_scan.c airkiss.c aes/aes.c aes/aes_dec.c
 OBJS = $(patsubst %.c,%.o,$(SRCS))
 
 LIBIW = -liw

aes/aes.c

@@ -0,0 +1,31 @@
+#include "aes.h"
+#include <stdio.h>
+#include <string.h>
+extern void * aes_decrypt_init(const u8 *, size_t);
+extern void * aes_decrypt(void *, const u8 *, u8 *);
+extern void * aes_decrypt_deinit(void *);
+
+int aes_128_cbc_decrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len)
+{
+	void *ctx;
+	u8 cbc[AES_BLOCK_SIZE], tmp[AES_BLOCK_SIZE];
+	u8 *pos = data;
+	int i, j, blocks;
+
+	ctx = aes_decrypt_init(key, 16);
+	if (ctx == NULL)
+		return -1;
+	memcpy(cbc, iv, AES_BLOCK_SIZE);
+
+	blocks = data_len / AES_BLOCK_SIZE;
+	for (i = 0; i < blocks; i++) {
+		memcpy(tmp, pos, AES_BLOCK_SIZE);
+		aes_decrypt(ctx, pos, pos);
+		for (j = 0; j < AES_BLOCK_SIZE; j++)
+			pos[j] ^= cbc[j];
+		memcpy(cbc, tmp, AES_BLOCK_SIZE);
+		pos += AES_BLOCK_SIZE;
+	}
+	aes_decrypt_deinit(ctx);
+	return 0;
+}

aes/aes.h

@@ -0,0 +1,10 @@
+#ifndef AES_H_AK
+#define AES_H_AK
+#define AES_BLOCK_SIZE 16
+#define AES_PRIV_SIZE (4 * 4 * 15 + 4)
+#define AES_PRIV_NR_POS (4 * 15)
+
+typedef unsigned char u8;
+typedef unsigned int u32;
+
+#endif