add "ipaccess-telnet" support, i.e. telnetting to an ip.access nanoBTS
There is a special MD5-challenge/response authentication after
establishing the telnet session to an ip.access nanoBTS / TCP port 3210.
The ipaccess-telnet program supports this mode of operation
diff --git a/util/Makefile.am b/util/Makefile.am
index 4500cea..7134d68 100644
--- a/util/Makefile.am
+++ b/util/Makefile.am
@@ -1,6 +1,9 @@
AM_CFLAGS = -I..
AM_LDFLAGS = -L..
+ipaccess_telnet_SOURCES = telnet-client-ipa.c ../libtelnet.h
+ipaccess_telnet_LDADD = ../libtelnet.la -lssl
+
telnet_client_SOURCES = telnet-client.c ../libtelnet.h
telnet_client_LDADD = ../libtelnet.la
@@ -10,4 +13,4 @@
telnet_proxy_SOURCES = telnet-proxy.c ../libtelnet.h
telnet_proxy_LDADD = ../libtelnet.la
-bin_PROGRAMS = telnet-client telnet-chatd telnet-proxy
+bin_PROGRAMS = telnet-client telnet-chatd telnet-proxy ipaccess-telnet
diff --git a/util/telnet-client-ipa.c b/util/telnet-client-ipa.c
new file mode 100644
index 0000000..4e22e20
--- /dev/null
+++ b/util/telnet-client-ipa.c
@@ -0,0 +1,327 @@
+/*
+ * Sean Middleditch
+ * sean@sourcemud.org
+ *
+ * The author or authors of this code dedicate any and all copyright interest
+ * in this code to the public domain. We make this dedication for the benefit
+ * of the public at large and to the detriment of our heirs and successors. We
+ * intend this dedication to be an overt act of relinquishment in perpetuity of
+ * all present and future rights to this code under copyright law.
+ */
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <poll.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <termios.h>
+#include <unistd.h>
+
+#ifdef HAVE_ZLIB
+#include "zlib.h"
+#endif
+
+#include "libtelnet.h"
+
+#define NANO_BTS_CLI_CLIENT 1
+
+#if NANO_BTS_CLI_CLIENT
+ #include <openssl/md5.h>
+#endif
+
+static struct termios orig_tios;
+static telnet_t *telnet;
+static int do_echo;
+
+static const telnet_telopt_t telopts[] = {
+ { TELNET_TELOPT_ECHO, TELNET_WONT, TELNET_DO },
+ { TELNET_TELOPT_TTYPE, TELNET_WILL, TELNET_DONT },
+ { TELNET_TELOPT_COMPRESS2, TELNET_WONT, TELNET_DO },
+ { TELNET_TELOPT_MSSP, TELNET_WONT, TELNET_DO },
+ { -1, 0, 0 }
+};
+
+static void _cleanup(void) {
+ tcsetattr(STDOUT_FILENO, TCSADRAIN, &orig_tios);
+}
+
+static void _input(char *buffer, int size) {
+ static char crlf[] = { '\r', '\n' };
+ int i;
+
+ for (i = 0; i != size; ++i) {
+ /* if we got a CR or LF, replace with CRLF
+ * NOTE that usually you'd get a CR in UNIX, but in raw
+ * mode we get LF instead (not sure why)
+ */
+ if (buffer[i] == '\r' || buffer[i] == '\n') {
+ if (do_echo)
+ printf("\r\n");
+ telnet_send(telnet, crlf, 2);
+ } else {
+ if (do_echo)
+ putchar(buffer[i]);
+ telnet_send(telnet, buffer + i, 1);
+ }
+ }
+ fflush(stdout);
+}
+
+static void _send(int sock, const char *buffer, size_t size) {
+ int rs;
+
+ /* send data */
+ while (size > 0) {
+ if ((rs = send(sock, buffer, size, 0)) == -1) {
+ fprintf(stderr, "send() failed: %s\n", strerror(errno));
+ exit(1);
+ } else if (rs == 0) {
+ fprintf(stderr, "send() unexpectedly returned 0\n");
+ exit(1);
+ }
+
+ /* update pointer and size to see if we've got more to send */
+ buffer += rs;
+ size -= rs;
+ }
+}
+
+static void _event_handler(telnet_t *telnet, telnet_event_t *ev,
+ void *user_data) {
+ int sock = *(int*)user_data;
+
+ switch (ev->type) {
+ /* data received */
+ case TELNET_EV_DATA:
+ printf("%.*s", (int)ev->size, ev->buffer);
+ break;
+ /* data must be sent */
+ case TELNET_EV_SEND:
+ _send(sock, ev->buffer, ev->size);
+ break;
+ /* request to enable remote feature (or receipt) */
+ case TELNET_EV_WILL:
+ /* we'll agree to turn off our echo if server wants us to stop */
+ if (ev->telopt == TELNET_TELOPT_ECHO)
+ do_echo = 0;
+ break;
+ /* notification of disabling remote feature (or receipt) */
+ case TELNET_EV_WONT:
+ if (ev->telopt == TELNET_TELOPT_ECHO)
+ do_echo = 1;
+ break;
+ /* request to enable local feature (or receipt) */
+ case TELNET_EV_DO:
+ break;
+ /* demand to disable local feature (or receipt) */
+ case TELNET_EV_DONT:
+ break;
+ /* respond to particular subnegotiations */
+ case TELNET_EV_SUBNEGOTIATION:
+ /* if they just asked for our terminal type, response with it */
+ /* respond with our terminal type */
+ if (ev->telopt == TELNET_TELOPT_TTYPE &&
+ ev->argc >= 1 && ev->argv[0][0] == TELNET_TTYPE_SEND) {
+ telnet_format_sb(telnet, TELNET_TELOPT_TTYPE, 1,
+ TELNET_TTYPE_IS, getenv("TERM"));
+ }
+ break;
+ /* error */
+ case TELNET_EV_ERROR:
+ fprintf(stderr, "ERROR: %s\n", ev->buffer);
+ exit(1);
+ default:
+ /* ignore */
+ break;
+ }
+}
+
+#if NANO_BTS_CLI_CLIENT
+
+#define KEY "Sh1n30nY0uCra2yD1am0nd"
+
+void compute_response(unsigned char *ubChallenge, unsigned char *ubResponse)
+{
+ MD5_CTX md5;
+ int i;
+
+ MD5_Init(&md5);
+
+ for(i = 0; i < 4; i++)
+ {
+ MD5_Update(&md5, (unsigned char *)KEY, strlen(KEY));
+ MD5_Update(&md5, ubChallenge, 16);
+ }
+
+ MD5_Final(ubResponse, &md5);
+}
+
+#endif
+
+int main(int argc, char **argv) {
+ char buffer[512];
+ int rs;
+ int sock;
+ struct sockaddr_in addr;
+ struct pollfd pfd[2];
+ struct addrinfo *ai;
+ struct addrinfo hints;
+ struct termios tios;
+
+ /* check usage */
+ if (argc != 3) {
+ fprintf(stderr, "Usage:\n ./telnet-client <host> <port>\n");
+ return 1;
+ }
+
+ /* look up server host */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+ if ((rs = getaddrinfo(argv[1], argv[2], &hints, &ai)) != 0) {
+ fprintf(stderr, "getaddrinfo() failed for %s: %s\n", argv[1],
+ gai_strerror(rs));
+ return 1;
+ }
+
+ /* create server socket */
+ if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
+ fprintf(stderr, "socket() failed: %s\n", strerror(errno));
+ return 1;
+ }
+
+ /* bind server socket */
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+ fprintf(stderr, "bind() failed: %s\n", strerror(errno));
+ return 1;
+ }
+
+ /* connect */
+ if (connect(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
+ fprintf(stderr, "server() failed: %s\n", strerror(errno));
+ return 1;
+ }
+
+ /* free address lookup info */
+ freeaddrinfo(ai);
+
+#if NANO_BTS_CLI_CLIENT
+
+ {
+ // nanoBTS Challenge/Response
+
+ unsigned char ubResponse[18];
+
+ #define CLI_USER "CLICLIENT\n"
+
+ // send client name
+
+ if ((rs = send(sock, CLI_USER, strlen(CLI_USER), 0)) == -1) {
+ fprintf(stderr, "send() failed: %s\n", strerror(errno));
+ exit(1);
+ } else if (rs == 0) {
+ fprintf(stderr, "send() unexpectedly returned 0\n");
+ exit(1);
+ }
+
+ // receive challenge
+
+ if ((rs = recv(sock, buffer, sizeof(buffer), 0)) > 0) {
+ if(rs != 18 || buffer[0] != '<' || buffer[17] != '>') {
+ fprintf(stderr, "unexpected response\n");
+ exit(1);
+ }
+ } else if (rs == 0) {
+ fprintf(stderr, "recv(client) unexpectedly returned 0\n");
+ exit(1);
+ } else {
+ fprintf(stderr, "recv(client) failed: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+
+ // calculate response
+
+ memset(&ubResponse, 0, sizeof(ubResponse));
+ compute_response(buffer + 1, ubResponse + 1);
+ ubResponse[0] = '<';
+ ubResponse[17] = '>';
+
+ // send response
+
+ if ((rs = send(sock, ubResponse, sizeof(ubResponse), 0)) == -1) {
+ fprintf(stderr, "send() failed: %s\n", strerror(errno));
+ exit(1);
+ } else if (rs == 0) {
+ fprintf(stderr, "send() unexpectedly returned 0\n");
+ exit(1);
+ }
+ }
+
+#endif
+
+ /* get current terminal settings, set raw mode, make sure we
+ * register atexit handler to restore terminal settings
+ */
+
+ tcgetattr(STDOUT_FILENO, &orig_tios);
+ atexit(_cleanup);
+ tios = orig_tios;
+ cfmakeraw(&tios);
+ tcsetattr(STDOUT_FILENO, TCSADRAIN, &tios);
+
+ /* set input echoing on by default */
+ do_echo = 1;
+
+ /* initialize telnet box */
+ telnet = telnet_init(telopts, _event_handler, 0, &sock);
+
+ /* initialize poll descriptors */
+ memset(pfd, 0, sizeof(pfd));
+ pfd[0].fd = STDIN_FILENO;
+ pfd[0].events = POLLIN;
+ pfd[1].fd = sock;
+ pfd[1].events = POLLIN;
+ /* loop while both connections are open */
+ while (poll(pfd, 2, -1) != -1) {
+ /* read from stdin */
+ if (pfd[0].revents & POLLIN) {
+ if ((rs = read(STDIN_FILENO, buffer, sizeof(buffer))) > 0) {
+ _input(buffer, rs);
+ } else if (rs == 0) {
+ break;
+ } else {
+ fprintf(stderr, "recv(server) failed: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+ }
+
+ /* read from client */
+ if (pfd[1].revents & POLLIN) {
+ if ((rs = recv(sock, buffer, sizeof(buffer), 0)) > 0) {
+ telnet_recv(telnet, buffer, rs);
+ } else if (rs == 0) {
+ break;
+ } else {
+ fprintf(stderr, "recv(client) failed: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+ }
+ }
+
+ /* clean up */
+ telnet_free(telnet);
+ close(sock);
+
+ return 0;
+}
+