加密IC 在android 機子上的簡單應用
阿新 • • 發佈：2019-01-08
原理：
產生一個組隨機機，寫入加密IC ，再從IC 中讀出來一組數，經演算法計算後，判斷之前的隨機數和計算的結果一樣，就證明此IC 為加密 IC ..因為加密演算法保密和隨機性比較大，防止抄板效果不錯。
kernel 層：
保證 i2c 通就行。不需要額外驅動。
hardware 層，通用程式碼如下。如果判斷沒有此 IC ,就重啟機子。此程式碼裡 隨機數就用的當前的時間
#define _GNU_SOURCE #include <string.h> #include <stdlib.h> #include<sys/socket.h> #include<arpa/inet.h> #include <linux/if.h> #include <sys/ioctl.h> #include <netinet/ether.h> #include <pthread.h> #include <signal.h> #include <utils/Log.h> #include <cutils/log.h> #include <hardware/hardware.h> #include <fcntl.h> #include <errno.h> #include <cutils/atomic.h> #include <stdio.h> #include <stdlib.h> #include <linux/types.h> #include <unistd.h> #include <sys/types.h> #include <sys/ioctl.h> #include <string.h> #include <time.h> #include <sys/reboot.h> #ifdef LOG_TAG #undef LOG_TAG #define LOG_TAG "encrypt_ic" #endif #define DEVICE_NAME "/dev/i2c-4" #define MODULE_NAME "iic" #define MODULE_AUTHOR "[email protected]" #define I2C_RETRIES 0x0701/* number of times a device address should be polled when not acknowledging */ #define I2C_TIMEOUT 0x0702/* set timeout in units of 10 ms */ #define I2C_RDWR 0x0707 int fd; /*********定義struct i2c_rdwr_ioctl_data和struct i2c_msg，要和核心一致*******/ struct i2c_msg { __u16 addr; /* slave address */ __u16 flags; #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ #define I2C_M_RD 0x0001 /* read data, from slave to master */ #define I2C_M_STOP 0x8000 /* if I2C_FUNC_PROTOCOL_MANGLING */ #define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_NOSTART */ #define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */ #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */ #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */ #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ __u16 len; /* msg length */ __u8 *buf; /* pointer to msg data */ __u32 scl_rate; /* add by kfx */ }; /* This is the structure as used in the I2C_RDWR ioctl call */ struct i2c_rdwr_ioctl_data { struct i2c_msg *msgs;/* pointers to i2c_msgs */ int nmsgs; /* number of i2c_msgs */ }; struct i2c_rdwr_ioctl_data iic_data; int ret; static int iic_write(unsigned char* dataBuf, unsigned char slaveAddr, unsigned char subAddr, int len) { int count = 0; unsigned char data[9]; unsigned char bytes; data[0] = subAddr; memcpy(&data[1], dataBuf, 8); iic_data.nmsgs=1; (iic_data.msgs[0]).len=len; //寫入地址位和資料長度 (iic_data.msgs[0]).addr=slaveAddr;// 裝置地址0x50 (iic_data.msgs[0]).flags=0; //write (iic_data.msgs[0]).scl_rate = 100000; (iic_data.msgs[0]).buf=data; ret=ioctl(fd,I2C_RDWR,(unsigned long)&iic_data); if(ret<0){ ALOGI("IIC HAL ioctl error"); } return 0; } static int iic_read(unsigned char* dataBuf, unsigned char slaveAddr, unsigned char subAddr, int len) { iic_data.nmsgs=2; (iic_data.msgs[0]).len=1; (iic_data.msgs[0]).addr=slaveAddr; // 裝置地址 (iic_data.msgs[0]).flags=0;//write (iic_data.msgs[0]).buf= &subAddr; (iic_data.msgs[0]).scl_rate = 100000; (iic_data.msgs[1]).len=len; (iic_data.msgs[1]).addr=slaveAddr; // 裝置地址 (iic_data.msgs[1]).flags=I2C_M_RD;//read (iic_data.msgs[1]).buf= dataBuf; (iic_data.msgs[1]).scl_rate = 100000; if(ioctl(fd, I2C_RDWR,(unsigned long)&iic_data)<0){ ALOGE("ioctl read error"); } ALOGI("IIC read HAL: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x", dataBuf[0], dataBuf[1], dataBuf[2], dataBuf[3], dataBuf[4], dataBuf[5], dataBuf[6], dataBuf[7], dataBuf[8], dataBuf[9]); return 0; } int main(int argc, char *argv[]) { unsigned char write_data[8]; unsigned char read_data[10]; unsigned char tx_data[10]; unsigned char rx_data[8]; struct tm *time_now; time_t time_second; time(&time_second); time_now = localtime(&time_second); memset(write_data, 0x68, 8); write_data[0] = time_now->tm_sec; write_data[1] = time_now->tm_min; write_data[2] = time_now->tm_hour; write_data[3] = time_now->tm_mday; write_data[4] = time_now->tm_mon; write_data[5] = time_now->tm_year; write_data[6] = time_now->tm_wday; if((fd = open(DEVICE_NAME, O_RDWR)) == -1) { ALOGE("iic Stub hal: failed to open /dev/i2c-1 -- %s.", strerror(errno)); return -EFAULT; }else{ ALOGV("iic Stub hal: open %s successfully.", DEVICE_NAME); iic_data.nmsgs=2; iic_data.msgs=(struct i2c_msg*)malloc(iic_data.nmsgs*sizeof(struct i2c_msg)); if(!iic_data.msgs){ ALOGE("malloc error"); close(fd); exit(1); } ioctl(fd, I2C_TIMEOUT, 2);//設定超時時間 ioctl(fd, I2C_RETRIES, 1);//設定重發次數 } iic_write(write_data, 0x60, 0xa0, 9); iic_read(read_data,0x60,0xa0, 10); //copy the encrypt ic data to soft input memcpy(tx_data, read_data, 10); EDesEn_Crypt(tx_data, rx_data); //ALOGI("is soft we get the data: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x", rx_data[0], rx_data[1], rx_data[2], rx_data[3], rx_data[4], rx_data[5], rx_data[6], rx_data[7]); ALOGI("is soft we get the data: %d, %d, %d, %d, %d, %d, %d, %d", rx_data[0], rx_data[1], rx_data[2], rx_data[3], rx_data[4], rx_data[5], rx_data[6], rx_data[7]); if(memcmp(write_data, rx_data, 8) == 0 ) ALOGD("read encrypt ic OKay & the devices is hello"); else { ALOGD("read encrypt ic the devices is not hello, so reboot"); sync(); // 同步磁碟資料,將快取資料回寫到硬碟,以防資料丟失[luther.gliethttp] return reboot(RB_AUTOBOOT); } return 0; }
Android.mk 如下， licsc.a 為演算法庫。mm 後產生一個 i2c_write 的檔案在 /system/bin/
LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE_TAGS := optional LOCAL_PRELINK_MODULE := false #LOCAL_MODULE_RELATIVE_PATH := hw LOCAL_SRC_FILES := i2c_command.c # All of the shared libraries we link against. LOCAL_SHARED_LIBRARIES := \ libutils libc libcutils LOCAL_LDFLAGS = $(LOCAL_PATH)/libsc.a LOCAL_MODULE := i2c_write include $(BUILD_EXECUTABLE)
以上檔案編譯好後，手動可以在板子上敲命令 ./i2c_write 可以檢視
I/encrypt_ic( 6299): IIC read HAL: 0xff, 0x31, 0xe7, 0xd3, 0x3f, 0x4e, 0x88, 0x2a, 0xa7, 0x5b
I/encrypt_ic( 6299): is soft we get the data: 33, 0, 13, 1, 0, 111, 6, 104
D/encrypt_ic( 6299): read encrypt ic OKay & the devices is hello
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測試OK 後，把其功能加到系統。
由於 android 可以定製。決定在 bootanimation 通過 init.rc 這裡進行判斷。
程式碼
--- a/frameworks/base/cmds/bootanimation/bootanimation_main.cpp
+++ b/frameworks/base/cmds/bootanimation/bootanimation_main.cpp
@@ -43,6 +43,8 @@ int main(int argc, char** argv)
#if defined(HAVE_PTHREADS)
setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_DISPLAY);
#endif
+ ALOGE("!!!!!!!!!!!!!! Now check the ic encrypt . if the IC check fail .the system will be reboot");
+ property_set("ctl.start", "ic_encrypt");
char value[PROPERTY_VALUE_MAX];
property_get("debug.sf.nobootanimation", value, "0");--- a/device/rockchip/rk3288/init.rc
+++ b/device/rockchip/rk3288/init.rc
@@ -642,3 +642,11 @@ service drawpath /system/bin/drawpath
class main
disabled
oneshot
+
+
+service ic_encrypt /system/bin/i2c_write
+ class main
+ disabled
+ oneshot
+
+編譯刷機後，經驗證：在沒有 加密ic 或者 ic 讀寫出錯 的機子上，機子啟動不了，會不斷重啟
read encrypt ic the devices is not hello, so reboot在有對應加密演算法會正常重啟。
log 就會看到
ead encrypt ic OKay & the devices is hello
備註：
此 i2c 用的是連續寫 8個位元組 和 讀 10 個位元組的方法