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#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <poll.h>
#include <unistd.h>
#include "util.h"
#include "sshnc.h"
static bool prompt_yn(const char *text) {
printf("%s [y/n] ", text);
fflush(stdout);
bool response;
char *line = NULL;
size_t linelen = 0;
while (true) {
ssize_t nr = getline(&line, &linelen, stdin);
if (nr == -1) {
perror("getline");
exit(1);
}
while (nr > 0 && isspace(line[nr - 1])) nr--;
for (ssize_t i = 0; i < nr; i++) line[i] = tolower(line[i]);
if ((nr == 1 && line[0] == 'y') || (nr == 3 && memcmp(line, "yes", 3) == 0)) {
response = true;
break;
}
if ((nr == 1 && line[0] == 'n') || (nr == 2 && memcmp(line, "no", 2) == 0)) {
response = false;
break;
}
printf("Please answer with 'y', 'n', 'yes' or 'no'. [y/n] ");
fflush(stdout);
}
free(line);
return response;
}
static bool hostkey_checker(const unsigned char *hash, size_t length, void *userdata) {
(void)userdata;
printf("Server host key hash: %s\n", sshnc_print_hash(hash, length));
bool response = prompt_yn(
"Does this hash match the one given to you by the server administrator, or by a\n"
"member that you trust and is already connected to the server?");
if (!response) {
printf("Disconnecting.\n");
}
return response;
}
int main(int argc, char **argv) {
const char *server_host = NULL;
int port = 2222;
if (argc != 2) {
fprintf(stderr, "Usage: %s <server[:port]>\n", argv[0]);
fprintf(stderr, "If port is not specified, %d is assumed.\n", port);
return 1;
}
if (!parse_host_port(argv[1], &server_host, &port)) {
fprintf(stderr, "Cannot parse host:port from argument '%s'\n", argv[1]);
return 1;
}
struct sshnc_client *client;
enum sshnc_retval ret = sshnc_connect(
server_host, port, "tomsg", "tomsg", hostkey_checker, NULL, &client);
if (ret != SSHNC_OK) {
fprintf(stderr, "Could not connect: %s\n", sshnc_strerror(ret));
return 1;
}
struct pollfd polls[2];
polls[0] = (struct pollfd){
.fd = sshnc_poll_fd(client),
.events = POLLIN,
};
polls[1] = (struct pollfd){
.fd = STDIN_FILENO,
.events = POLLIN,
};
while (true) {
int pollret = poll(polls, sizeof polls / sizeof polls[0], -1);
if (pollret < 0) {
perror("poll");
goto cleanup;
}
if (polls[0].revents & (POLLERR | POLLNVAL)) {
fprintf(stderr, "Error reading from SSH socket\n");
goto cleanup;
}
if (polls[1].revents & (POLLERR | POLLNVAL)) {
fprintf(stderr, "Error reading from stdin\n");
goto cleanup;
}
if (polls[0].revents & (POLLIN | POLLHUP)) {
// Get all data currently available
bool should_exit = false;
while (true) {
char buffer[4096];
size_t length = 0;
ret = sshnc_maybe_recv(client, sizeof buffer, buffer, &length);
if (ret == SSHNC_AGAIN) break;
if (ret == SSHNC_EOF) {
should_exit = true;
break;
} else if (ret == SSHNC_OK) {
fwrite(buffer, 1, length, stdout);
} else {
fprintf(stderr, "Error on SSH recv: %s\n", sshnc_strerror(ret));
goto cleanup;
}
}
if (should_exit) break;
}
if (polls[1].revents & (POLLIN | POLLHUP)) {
char buffer[4096];
ssize_t nr = read(STDIN_FILENO, buffer, sizeof buffer);
if (nr < 0) {
perror("Error reading from stdin");
goto cleanup;
}
if (nr == 0) {
break;
}
ret = sshnc_send(client, buffer, nr);
if (ret == SSHNC_EOF) {
break;
} else if (ret != SSHNC_OK) {
fprintf(stderr, "Error on SSH send: %s\n", sshnc_strerror(ret));
goto cleanup;
}
}
}
sshnc_close(client);
return 0;
cleanup:
sshnc_close(client);
return 1;
}
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