#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>
#include <ctype.h>

#define LIBSSH_STATIC 1
#include <libssh/libssh.h>

#define CBC 1
#define CTR 1
#define ECB 1

#include "aes.h"

#define BUFFER_SIZE 1024

int verify_knownhost(ssh_session session)
{
    enum ssh_known_hosts_e state;
    unsigned char *hash = NULL;
    ssh_key srv_pubkey = NULL;
    size_t hlen;
    char *hexa;
    int rc;

    rc = ssh_get_server_publickey(session, &srv_pubkey);
    if (rc < 0) {
        return -1;
    }

    rc = ssh_get_publickey_hash(srv_pubkey, SSH_PUBLICKEY_HASH_SHA1, &hash, &hlen);
    ssh_key_free(srv_pubkey);
    if (rc < 0) {
        return -1;
    }

    state = ssh_session_is_known_server(session);
    switch (state) {
    case SSH_KNOWN_HOSTS_OK:
        /* OK */

        break;
    case SSH_KNOWN_HOSTS_CHANGED:
        fprintf(stderr, "Host key for server changed: it is now:\n");
        ssh_print_hash(SSH_PUBLICKEY_HASH_SHA256, hash, hlen);
        fprintf(stderr, "For security reasons, connection will be stopped\n");
        ssh_clean_pubkey_hash(&hash);

        return -1;
    case SSH_KNOWN_HOSTS_OTHER:
        fprintf(stderr, "The host key for this server was not found but an other" "type of key exists.\n");
        fprintf(stderr, "An attacker might change the default server key to" "confuse your client into thinking the key does not exist\n");
        ssh_clean_pubkey_hash(&hash);

        return -1;
    case SSH_KNOWN_HOSTS_NOT_FOUND:
        fprintf(stderr, "Could not find known host file.\n");
        fprintf(stderr, "If you accept the host key here, the file will be" "automatically created.\n");

        /* FALL THROUGH to SSH_SERVER_NOT_KNOWN behavior */

    case SSH_KNOWN_HOSTS_UNKNOWN:
        hexa = ssh_get_hexa(hash, hlen);
        fprintf(stderr, "The server is unknown. Do you trust the host key?\n");
        fprintf(stderr, "Public key hash: %s\n", hexa);
        ssh_string_free_char(hexa);
        ssh_clean_pubkey_hash(&hash);

        rc = ssh_session_update_known_hosts(session);
        if (rc < 0) {
            fprintf(stderr, "Error %s\n", strerror(errno));
            return -1;
        }

        break;
    case SSH_KNOWN_HOSTS_ERROR:
        fprintf(stderr, "Error %s", ssh_get_error(session));
        ssh_clean_pubkey_hash(&hash);
        return -1;
    }

    ssh_clean_pubkey_hash(&hash);
    return 0;
}

// 交互式外壳会话
int interactive_shell_session(ssh_session session, ssh_channel channel)
{
    int rc;

    rc = ssh_channel_request_pty(channel);
    if (rc != SSH_OK)
        return rc;

    rc = ssh_channel_change_pty_size(channel, 80, 24);
    if (rc != SSH_OK)
        return rc;

    rc = ssh_channel_request_shell(channel);
    if (rc != SSH_OK)
        return rc;

    char buffer[256];
    int nbytes, nwritten;

    while (ssh_channel_is_open(channel) && !ssh_channel_is_eof(channel)) {
        struct timeval timeout;
        ssh_channel in_channels[2], out_channels[2];
        fd_set fds;
        int maxfd;

        timeout.tv_sec = 30;
        timeout.tv_usec = 0;
        in_channels[0] = channel;
        in_channels[1] = NULL;
        FD_ZERO(&fds);
        FD_SET(0, &fds);
        FD_SET(ssh_get_fd(session), &fds);
        maxfd = ssh_get_fd(session) + 1;

        ssh_select(in_channels, out_channels, maxfd, &fds, &timeout);

        if (out_channels[0] != NULL) {
            nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
            if (nbytes < 0)
                return SSH_ERROR;
            if (nbytes > 0) {
                nwritten = write(1, buffer, nbytes);
                if (nwritten != nbytes)
                    return SSH_ERROR;
            }
        }

        if (FD_ISSET(0, &fds)) {
            nbytes = read(0, buffer, sizeof(buffer));
            if (nbytes < 0)
                return SSH_ERROR;
            if (nbytes > 0) {
                nwritten = ssh_channel_write(channel, buffer, nbytes);
                if (nbytes != nwritten)
                    return SSH_ERROR;
            }
        }
    }

    return rc;
}

// 执行远程命令
int execute_remote_command(ssh_channel channel, char *command)
{
    int rc;
    char buffer[256];
    int nbytes;

    rc = ssh_channel_request_exec(channel, command);
    if (rc != SSH_OK) {
        ssh_channel_close(channel);
        ssh_channel_free(channel);
        return rc;
    }

    nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
    while (nbytes > 0) {
        if (write(1, buffer, nbytes) != (unsigned int)nbytes) {
            ssh_channel_close(channel);
            ssh_channel_free(channel);
            return SSH_ERROR;
        }
        nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
    }

    if (nbytes < 0) {
        ssh_channel_close(channel);
        ssh_channel_free(channel);
        return SSH_ERROR;
    }

    return rc;
}

int show_remote_processes(ssh_session session, char *command, int is)
{
    int rc;
    ssh_channel channel;

    // 分配一个新的信道
    channel = ssh_channel_new(session);
    if (channel == NULL)
        return SSH_ERROR;

    // 分配好的信道
    rc = ssh_channel_open_session(channel);
    if (rc != SSH_OK) {
        ssh_channel_free(channel);
        return rc;
    }

    if (is) {
        interactive_shell_session(session, channel);
    } else {
        execute_remote_command(channel, command);
    }

    ssh_channel_send_eof(channel);
    ssh_channel_close(channel);
    ssh_channel_free(channel);

    return SSH_OK;
}

int authenticate_pubkey(ssh_session session, char *priv_name, char *passphrase)
{
    int rc;
    ssh_key pkey = NULL;

    //从文件中个导入密钥
    rc = ssh_pki_import_privkey_file(priv_name, passphrase, NULL, NULL, &pkey);
    if (rc != SSH_OK) {
        exit(-1);
    }

    ssh_userauth_publickey(session, NULL, pkey);

    ssh_key_free(pkey);
    return rc;
}

static int oneHexChar2Hex(char hex)
{
    int outHex = 0;
    if (isdigit(hex)) {
        outHex = hex - '0';
    } else if (isupper(hex)) {
        outHex = hex - 'A' + 10;
    } else {
        outHex = hex - 'a' + 10;
    }
    return outHex;
}

static int HexString2Hex(char *inHexString, char *outHex, int count)
{
    int ret = -1;
    int len = 0;
    int i;
    char ch1, ch2;

    if (NULL == inHexString)
        return -1;

    len = count;

    if (len < 1)
        return -1;

    len &= ~1;
    for (i = 0; i < len; i += 2) {
        ch1 = inHexString[i];
        ch2 = inHexString[i + 1];
        outHex[i / 2 + 1] = 0;
        if (isxdigit(ch1) && isxdigit(ch2)) {
            ch1 = oneHexChar2Hex(ch1);
            ch2 = oneHexChar2Hex(ch2);
            outHex[i / 2] = (ch1 << 4) | ch2;
        } else {
            goto EXIT;
        }
    }
    return 0;
EXIT:
    return ret;
}

static int rsa_file()
{
    static uint8_t key[16] = "aixiao";

    struct AES_ctx ctx;
    AES_init_ctx(&ctx, key);

    static char temp[] =
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
    uint8_t Hex_string[sizeof(temp) / 2];
    bzero(Hex_string, 0);
    HexString2Hex((char *)temp, (char *)Hex_string, sizeof(temp));

    AES_ECB_decrypt(&ctx, Hex_string);
    //printf("%s\n", Hex_string);

    FILE *fp = fopen("aixiao.rsa", "w");
    if (fp == NULL) {
        perror("fopen");
        return -1;
    }

    fwrite(Hex_string, sizeof(Hex_string), 1, fp);

    fclose(fp);
    return 0;
}

static void help_information() {
    puts("\n"
"remote command\n"
"Author: aixiao@aixiao.me\n"
"Usage: [-?hlfpkib]\n"
"\n"
"   Options:\n"
"       -l          : host name\n"
"       -p          : host port\n"
"       -u          : user name(default: root)\n"
"       -e          : user passwd\n"
"       -k          : private key passwd\n"
"       -f          : private key file\n"
"       -i          : interactive shell session\n"
"       -c          : command\n"
"       -? -h       : help information\n");
    exit(0);
}

int main(int argc, char *argv[], char **env)
{

    int rc;
    int is = 0;
    int verbosity = SSH_LOG_PROTOCOL;
    ssh_session my_ssh_session;

    char host_ip[BUFFER_SIZE];
    char password[BUFFER_SIZE];
    char user[BUFFER_SIZE];
    char *priv_name = "aixiao.rsa";     // 私钥文件名称
    char priv_passwd[BUFFER_SIZE];      // 私钥的解密密钥
    char command[BUFFER_SIZE];
    int host_port = 22;

    memset(host_ip, 0, BUFFER_SIZE);
    memset(password, 0, BUFFER_SIZE);
    memset(user, 0, BUFFER_SIZE);
    memset(priv_passwd, 0, BUFFER_SIZE);
    memset(command, 0, BUFFER_SIZE);

    memcpy(user, "root", 4);

    int opt;
    char optstrs[] = "-:l:p:u:e:k:f:ic:h?";
    while (-1 != (opt = getopt(argc, argv, optstrs))) {
        switch (opt) {
        case 'l':
            strcpy(host_ip, optarg);
            break;
        case 'p':
            host_port = atoi(optarg);
            break;
        case 'u':
            strcpy(user, optarg);
            break;
        case 'e':
            strcpy(password, optarg);
            break;
        case 'k':
            memset(password, 0, BUFFER_SIZE);
            strcpy(priv_passwd, optarg);
            rsa_file();
            break;
        case 'f':
            priv_name = optarg;
            break;
        case 'i':
            is = 1;
            break;
        case 'c':
            strcpy(command, optarg);
            break;
        case ':':
            printf("\nMissing argument after: -%c\n", optopt);
            exit(0);
        case 'h':
        case '?':
            help_information();
        default:
            help_information();
        }
    }

    my_ssh_session = ssh_new();
    if (my_ssh_session == NULL) {
        exit(-1);
    }

    ssh_options_set(my_ssh_session, SSH_OPTIONS_HOST, host_ip);
    ssh_options_set(my_ssh_session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
    ssh_options_set(my_ssh_session, SSH_OPTIONS_PORT, &host_port);

    rc = ssh_connect(my_ssh_session);

    // Verify the server's identity
    if (verify_knownhost(my_ssh_session) < 0) {
        ssh_disconnect(my_ssh_session);
        ssh_free(my_ssh_session);
        exit(-1);
    }

    if (strlen(password) > 1) {
        // Authenticate ourselves
        rc = ssh_userauth_password(my_ssh_session, user, password);
        if (rc != SSH_AUTH_SUCCESS) {
            fprintf(stderr, "Error authenticating with password: %s\n", ssh_get_error(my_ssh_session));
            ssh_disconnect(my_ssh_session);
            ssh_free(my_ssh_session);
            exit(-1);
        }
    } else {
        // 私钥认证
        authenticate_pubkey(my_ssh_session, priv_name, priv_passwd);
    }

    // 传递远程命令
    show_remote_processes(my_ssh_session, command, is);

    // 从一个会话断开连接(服务器或客户端)
    ssh_disconnect(my_ssh_session);
    // 释放已分配的SSH会话句柄
    ssh_free(my_ssh_session);

    remove("aixiao.rsa");

    return 0;
}