Android keystore jks pk8 x509.pem

Lists entries in a keystore

  1. keytool -list -v -keystore platform.keystore

Generate Signed APK Using jarsigner

  1. jarsigner -verbose -keystore platform.keystore -signedjar app-debug-signed.apk app-debug.apk alias-name

pk8 & x509.pem -> keystore

  1. ./keytool-importkeypair -k ./oldplatform.keystore -p password -pk8 ../platform.pk8 -cert ../platform.x509.pem -alias alias-name

keystore -> p12 -> jks

  1. keytool -importkeystore -srckeystore platform.keystore -srcstoretype JKS -deststoretype PKCS12 -destkeystore platform.keystore.p12
  2. keytool -v -importkeystore -srckeystore platform.keystore.p12 -srcstoretype PKCS12 -destkeystore platform.keystore.jks -deststoretype JKS

Generate Signed APK Using Android Studio


Using X11 for GUI

Result

Code

  1. #include <X11/Xlib.h>
  2. #include <X11/Xlocale.h>
  3. #include <stdio.h>
  4. #include <stdlib.h>
  5. #include <string.h>
  6.  
  7. void
  8. DrawCenteredMbString(Display* dpy, Window w, XFontSet fontset, GC gc, char* str, int num_bytes, int x, int y, int width,
  9. 	int height) {
  10. 	XRectangle boundingbox;
  11. 	XRectangle dummy;
  12. 	int originx, originy;
  13.  
  14. 	(void)XmbTextExtents(fontset, str, num_bytes, &dummy, &boundingbox);
  15.  
  16. 	originx = x + (width - boundingbox.width) / 2 - boundingbox.x;
  17. 	originy = y + (height - boundingbox.height) / 2 - boundingbox.y;
  18.  
  19. 	XmbDrawString(dpy, w, fontset, gc, originx, originy, str, num_bytes);
  20. }
  21.  
  22. int main(void) {
  23. 	Display* d;
  24. 	Window w;
  25. 	GC gc;
  26. 	XGCValues values;
  27. 	XEvent e;
  28. 	XFontStruct* fs, * fs16;
  29. 	char** fonts;
  30. 	int font_count;
  31. 	XFontSet fontset;
  32. 	char** missing_charsets;
  33. 	int num_missing_charsets;
  34. 	char* default_string;
  35.  
  36. 	char* msg = "Hello, World!";
  37. 	char* msg2 = "啊,世界,啊啊啊";
  38. 	int s;
  39.  
  40. 	if (setlocale(LC_ALL, "") == NULL) {
  41. 		printf("cannot set locale \n");
  42. 		exit(1);
  43. 	}
  44.  
  45. 	if (!XSupportsLocale()) {
  46. 		printf("X does not support locale %s\n", setlocale(LC_ALL, NULL));
  47. 		exit(1);
  48. 	}
  49.  
  50. 	if (XSetLocaleModifiers("") == NULL) {
  51. 		printf("Warning: cannot set locale modifiers\n");
  52. 	}
  53.  
  54.  
  55. 	d = XOpenDisplay(NULL);
  56. 	if (d == NULL) {
  57. 		fprintf(stderr, "Cannot open display\n");
  58. 		exit(1);
  59. 	}
  60.  
  61. 	fonts = XListFonts(d, "*hanzi*", 10000, &font_count);
  62. 	for (int i = 0; i < font_count; i++)
  63. 		printf("%s\n", fonts[i]);
  64. 	XFreeFontNames(fonts);
  65.  
  66. 	if ((fs16 = XLoadQueryFont(d, "hanzigb16st")) == NULL) {
  67. 		printf("Cannot load font\n");
  68. 		exit(1);
  69. 	}
  70.  
  71. 	s = DefaultScreen(d);
  72. 	w = XCreateSimpleWindow(d, RootWindow(d, s), 100, 100, 500, 500, 1,
  73. 		777215, 111111);
  74. 	printf("BlackPixel(d, s) is %d\n", (int)BlackPixel(d, s));
  75. 	printf("WhitePixel(d, s) is %d\n", (int)WhitePixel(d, s));
  76.  
  77. 	fontset = XCreateFontSet(
  78. 		d, "-*-*-*-*-*-*-16-*-*-*-*-*-*-*",
  79. 		&missing_charsets, &num_missing_charsets,
  80. 		&default_string);
  81. 	if (num_missing_charsets > 0) {
  82. 		printf("The following charsets are missing\n");
  83. 		for (int i = 0; i < num_missing_charsets; i++) {
  84. 			printf("%s \n", missing_charsets);
  85. 			printf("The string is %s \n", default_string);
  86. 			printf("of any characters from those sets\n");
  87. 		}
  88. 		XFreeStringList(missing_charsets);
  89. 	}
  90. 	XSetLineAttributes(d, gc, 5, LineSolid, CapRound, JoinRound);
  91.  
  92.  
  93. 	XSelectInput(d, w, ExposureMask | KeyPressMask);
  94. 	gc = XCreateGC(d, w, 0, &values);
  95. 	XMapWindow(d, w);
  96.  
  97. 	int y = 50;
  98. 	for (int i = 0; i < 10; i++) {
  99.  
  100. 		//XFillRectangle(d, w, DefaultGC(d, s), 20, 20, 10, 10);
  101. 		XDrawString(d, w, DefaultGC(d, s), 10, y + i * 20, msg, strlen(msg));
  102.  
  103. 		//XSetFont(d, gc, fs16->fid);
  104. 		//XDrawString16(d, w, gc, 100, y + i * 20, (XChar2b *) msg2, strlen(msg2) / 2);
  105.  
  106. 		int msg_len = strlen(msg2);
  107.  
  108. 		DrawCenteredMbString(
  109. 			d, w, fontset, gc,
  110. 			msg2,
  111. 			msg_len, 50, y + i * 20, 100, 50);
  112.  
  113. 		XFlush(d);
  114. 		sleep(1);
  115.  
  116. 	}
  117.  
  118. 	/*while(1) {
  119. 		XNextEvent(d, &e);
  120. 		if (e.type == KeyPress)
  121. 		  break;
  122. 	}*/
  123.  
  124. 	XCloseDisplay(d);
  125. 	return 0;
  126. }

Calling a C Function From Lua

Prepare So

  1. #include <math.h>
  2. #include <lua.h>
  3. #include <lauxlib.h>
  4. #include <lualib.h>
  5.  
  6. static int my_sum(lua_State *L){
  7.     int d1 = luaL_checknumber(L, 1);
  8.     int d2 = luaL_checknumber(L, 2);
  9.     lua_pushnumber(L, d1+d2);
  10.     return 1;
  11. }
  12.  
  13. static int my_info(lua_State *L){
  14.     lua_pushstring(L, "qinuu");
  15.     return 1;
  16. }
  17.  
  18. static const struct luaL_Reg test_lib[] = {
  19.     {"my_sum" , my_sum},
  20.     {"my_info" , my_info},
  21.     {NULL, NULL}
  22. };
  23.  
  24. int luaopen_test_lib(lua_State *L){
  25.     //luaL_newlib(L, test_lib); // 5.2
  26.     luaL_register(L, "test_lib",test_lib); // lua 5.1
  27.     return 1;
  28. }

Test

  1. local my_lib = require "test_lib"
  2.  
  3. print(type(test_lib))
  4.  
  5. print(test_lib.my_sum(23,17))
  6.  
  7. print(test_lib.my_info())

Speed up by ignoring std::cout

Test Code

  1. #include <iostream>
  2.  
  3. int main(int argc, char *argv[])
  4. {
  5. 	//std::cout.setstate(std::ios_base::badbit);
  6. 	for(int i = 0; i < 100; i ++) {
  7. 		for(int i = 0; i < 100; i ++) {
  8. 			;//std::cout << "" << std::endl;
  9. 		}
  10. 	}
  11. 	return 0;
  12. }

Test it without std::cout

  1. root@imx6ul7d:~/tmp# time ./t1_1 
  2.  
  3. real    0m0.041s
  4. user    0m0.020s
  5. sys     0m0.000s

Test it with std::cout, but redirect to /dev/null

  1. root@imx6ul7d:~/tmp# time ./t1_0 > /dev/null
  2.  
  3. real    0m0.096s
  4. user    0m0.030s
  5. sys     0m0.030s

Test it with std::cout, but set io state

  1. root@imx6ul7d:~/tmp# time ./t1_2
  2.  
  3. real    0m0.061s
  4. user    0m0.040s
  5. sys     0m0.000s

Profile : Linux

Example 1

Add -pg

  1. arm-linux-gnueabihf-g++ -Wall -g -pg hello.cpp -o hello -std=c++17

Test

  1. root@imx6ul7d:~# gprof -b hello 
  2. Flat profile:
  3.  
  4. Each sample counts as 0.01 seconds.
  5.   %   cumulative   self              self     total           
  6.  time   seconds   seconds    calls   s/call   s/call  name    
  7. 100.00      3.45     3.45        1     3.45     3.45  hehe()
  8.   0.00      3.45     0.00        4     0.00     0.00  std::_Optional_base<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::_M_is_engaged() const
  9. ......

IPC Performance : Socket on ARM

Test Environment

CPU: Freescale i.MX6UL rev1.1 528 MHz
DRAM: 512 MiB

Test Code

  1. #include <stdlib.h>
  2. #include <sys/types.h>
  3. #include <sys/socket.h> 
  4. #include <netinet/in.h>
  5. #include <errno.h>
  6. #include <string.h>
  7. #include <unistd.h>
  8. #include <fcntl.h>
  9.  
  10. #define CLTIP "127.0.0.1"
  11. #define SRVPORT 10172
  12. #define MAX_NUM 1024
  13.  
  14. int main(int argc, char* argv[])
  15. {
  16. 	struct timeval tv_sta, tv_end;
  17.  
  18. 	gettimeofday(&tv_sta, NULL);
  19.  
  20. 	int i = 0;
  21. 	int total = 1;
  22. 	int is_printf = 1;
  23. 	if (argc > 1) {
  24. 		total = atoi(argv[1]);
  25. 	}
  26. 	if (argc > 2) {
  27. 		is_printf = atoi(argv[2]);
  28. 	}
  29.  
  30. 	for (i = 0; i < total; i++) {
  31.  
  32. 		int clientsock = socket(PF_INET, SOCK_STREAM, 0);
  33. 		if (clientsock < 0)
  34. 		{
  35. 			printf("socket creation failed\n");
  36. 			exit(-1);
  37. 		}
  38. 		if (is_printf)
  39. 			printf("socket create successfully.\n");
  40.  
  41. 		struct sockaddr_in clientAddr;
  42. 		clientAddr.sin_family = AF_INET;
  43. 		clientAddr.sin_port = htons((u_short)SRVPORT);
  44. 		clientAddr.sin_addr.s_addr = inet_addr(CLTIP);
  45.  
  46. 		int flags = fcntl(clientsock, F_GETFL, 0);
  47. 		fcntl(clientsock, F_SETFL, flags | O_NONBLOCK);
  48.  
  49. 		int n;
  50. 		if ((n = connect(clientsock, (struct sockaddr*) & clientAddr, sizeof(struct sockaddr))) < 0)
  51. 		{
  52. 			if (errno != EINPROGRESS) {
  53. 				printf("Connect error.IP[%s], port[%d]\n", CLTIP, clientAddr.sin_port);
  54. 				exit(-1);
  55. 			}
  56. 		}
  57.  
  58. 		if (n != 0) {
  59.  
  60. 			fd_set rset, wset;
  61. 			FD_ZERO(&rset);
  62. 			FD_SET(clientsock, &rset);
  63. 			wset = rset;
  64. 			struct timeval tval;
  65. 			tval.tv_sec = 1;
  66. 			tval.tv_usec = 0;
  67. 			if ((n = select(clientsock + 1, &rset, &wset, NULL, 3 ? &tval : NULL)) == 0) {
  68. 				printf("Connect TIMEOUT.IP[%s], port[%d]\n", CLTIP, clientAddr.sin_port);
  69. 				exit(-1);
  70. 			}
  71. 			if (FD_ISSET(clientsock, &rset) || FD_ISSET(clientsock, &wset)) {
  72. 				int error;
  73. 				int len = sizeof(error);
  74. 				if (getsockopt(clientsock, SOL_SOCKET, SO_ERROR, &error, &len) < 0) {
  75. 					printf("pending error");
  76. 					exit(-1);
  77. 				}
  78. 			}
  79. 			else {
  80. 				printf("select error: clientsock not set");
  81. 				exit(-1);
  82. 			}
  83.  
  84. 		}
  85. 		fcntl(clientsock, F_SETFL, flags);
  86.  
  87. 		if (is_printf)
  88. 			printf("Connect to IP[%s], port[%d]\n", CLTIP, clientAddr.sin_port);
  89.  
  90. 		const char* sendBuf = "{\"signalType\":\"CONFIG\", \"signalData\":[{\"id\":\"CONF_NAME\", \"value\":\"PPS_MChip1\"}]}";
  91. 		char recvBuf[MAX_NUM] = { 0 };
  92.  
  93. 		//while(gets(sendBuf) != '\0')
  94. 		{
  95. 			if (send(clientsock, sendBuf, strlen(sendBuf), 0) == -1)
  96. 			{
  97. 				printf("send error!\n");
  98. 			}
  99. 			if (is_printf)
  100. 				printf("send to server:%s\n", sendBuf);
  101. 			//memset(sendBuf, 0, sizeof(sendBuf));
  102.  
  103. 			{
  104. 				int timeOut = 3000;
  105. 				int nRet = 0;
  106. 				struct timeval timeout;
  107. 				fd_set recvset;
  108. 				FD_ZERO(&recvset);
  109. 				FD_SET(clientsock, &recvset);
  110. 				timeout.tv_sec = timeOut / 1000;
  111. 				timeout.tv_usec = timeOut % 1000;
  112. 				nRet = select(clientsock + 1, &recvset, 0, 0, &timeout);
  113. 				if (nRet <= 0)
  114. 				{
  115. 					printf("clientsock recv select is error!\n");
  116. 					exit(-1);
  117. 				}
  118. 			}
  119.  
  120. 			if (recv(clientsock, recvBuf, MAX_NUM, 0) == -1)
  121. 			{
  122. 				printf("rev error!\n");
  123. 			}
  124. 			if (is_printf)
  125. 				printf("receive from server:%s\n", recvBuf);
  126. 			if (strcmp(recvBuf, "Goodbye,my dear client!") == 0)
  127. 			{
  128. 				//break;
  129. 			}
  130. 			memset(recvBuf, 0, sizeof(recvBuf));
  131. 		}
  132. 		close(clientsock);
  133.  
  134. 	}
  135.  
  136. 	gettimeofday(&tv_end, NULL);
  137.  
  138. 	int total_millisecond = (tv_end.tv_sec * 1000 + tv_end.tv_usec / 1000) - (tv_sta.tv_sec * 1000 + tv_sta.tv_usec / 1000);
  139. 	int average_millisecond = (total_millisecond / total);
  140.  
  141. 	printf("total_millisecond : %ld total_nums : %d\n", total_millisecond, total);
  142. 	printf("average_millisecond   : %ld\n", average_millisecond);
  143.  
  144. 	return 0;
  145. }

Test Result

  1. root@imx6ul7d:~/tmp# ./a.out 1 0
  2. total_millisecond : 13 total_nums : 1
  3. average_millisecond   : 13
  4. root@imx6ul7d:~/tmp# ./a.out 10 0
  5. total_millisecond : 104 total_nums : 10
  6. average_millisecond   : 10
  7. root@imx6ul7d:~/tmp# ./a.out 100 0 
  8. total_millisecond : 1023 total_nums : 100
  9. average_millisecond   : 10
  10. root@imx6ul7d:~/tmp# ./a.out 1000 0
  11. total_millisecond : 10801 total_nums : 1000
  12. average_millisecond   : 10

How to expose a local server behind a NAT or firewall to the internet

Download FRP Server & Client

Modify frps.ini

  1. [root@VM_0_5_centos frp_0.25.3_linux_amd64]# cat frps.ini
  2. [common]
  3. bind_port = xxxxxx
  4. dashboard_port = xxxxxx
  5. dashboard_user = xxxxxxxxxxxxxxxx
  6. dashboard_pwd = xxxxxxxxxxxxxxxx
  7. allow_ports = xxxxx-xxxxx
  8. token = xxxxxxxxxxxxxxxx
  9. max_pool_count = 10
  10. pool_count = 3

Start frps

  1. [root@VM_0_5_centos frp_0.25.3_linux_amd64]# ./frps -c ./frps.ini

Modify frpc.ini

  1. root@imx6ul7d:~/frp# cat frpc.ini 
  2. [common]
  3. server_addr = qinuu.com
  4. server_port = xxxxxx
  5. token = xxxxxxxxxxxxxxxx
  6. [ssh]
  7. type = tcp
  8. local_ip = 127.0.0.1
  9. local_port = 22
  10. remote_port = xxxxxx

Start frpc

root@imx6ul7d:~/frp# ./frpc -c ./frpc.ini

Start a systemd service

[root@VM_0_5_centos frp_0.25.3_linux_amd64]# cat /lib/systemd/system/frps.service
[Unit]
Description=Frp Server Service
After=network.target
 
[Service]
Type=simple
User=nobody
Restart=on-failure
RestartSec=5s
ExecStart=/usr/local/frp/frp_0.25.3_linux_amd64/frps -c /usr/local/frp/frp_0.25.3_linux_amd64/frps.ini
 
[Install]
WantedBy=multi-user.targethis
 
[root@VM_0_5_centos frp_0.25.3_linux_amd64]# systemctl start frps
[root@VM_0_5_centos frp_0.25.3_linux_amd64]# systemctl enable frps
[root@VM_0_5_centos frp_0.25.3_linux_amd64]# systemctl status frps

Cross compile wget with openssl for ARM

Config OpenSSL

tar xvf openssl-1.1.1b.tar.gz 
cd openssl-1.1.1b/
mkdir __install
./config --prefix=$PWD/__install no-asm shared

Edit Makefile

PLATFORM=linux-armv4
CROSS_COMPILE=arm-linux-gnueabihf-
delete "-m32" "-m64"

Compile OpenSSL

make
make install

Config Wget && Make

tar zxvf wget-1.20.1.tar.gz
cd wget-1.20.1
./configure --prefix=$PWD/__install --host=arm-linux CC=arm-linux-gnueabihf-gcc --with-ssl=openssl --with-libssl-prefix=/root/Downloads/wget_arm/openssl-1.1.1b/__install --without-zlib
make 
make install

./xxx: /usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.22′ not found (required by ./xxx)

Copy libstdc++.so.6.0.24 from cross compiler (7.3.1)

cd /usr/lib
mv libstdc++.so.6 libstdc++.so.6.bak
ln -s libstdc++.so.6.0.24 libstdc++.so.6
chmod 777 libstdc++.so.6

Now, it will be like this !

root@imx6ul7d:/usr/lib# ls -al libstdc++.so.6*
lrwxrwxrwx 1 root root      19 Sep 16 23:03 libstdc++.so.6 -> libstdc++.so.6.0.24
-rwxr-xr-x 1 root root 1240644 Sep  9 02:04 libstdc++.so.6.0.21
-rwxrwxrwx 1 root root 9459568 Sep 16 23:35 libstdc++.so.6.0.24
lrwxrwxrwx 1 root root      19 Jan  1  1970 libstdc++.so.6.bak -> libstdc++.so.6.0.21
-rwxr-xr-x 1 root root 9459568 Sep 16 23:11 libstdc++.so.6.bak_24