/* Copyright (C) The libssh2 project and its contributors.
 *
 * Sample showing how to do an SCP upload.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include "libssh2_setup.h"
#include <libssh2.h>

#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include <stdio.h>

static const char *pubkey = "/home/username/.ssh/id_rsa.pub";
static const char *privkey = "/home/username/.ssh/id_rsa";
static const char *username = "username";
static const char *password = "password";
static const char *loclfile = "scp_write.c";
static const char *scppath = "/tmp/TEST";

int main(int argc, char *argv[])
{
    uint32_t hostaddr;
    libssh2_socket_t sock;
    int i, auth_pw = 1;
    struct sockaddr_in sin;
    const char *fingerprint;
    int rc;
    LIBSSH2_SESSION *session = NULL;
    LIBSSH2_CHANNEL *channel;
    FILE *local;
    char mem[1024];
    size_t nread;
    char *ptr;
    struct stat fileinfo;

#ifdef _WIN32
    WSADATA wsadata;

    rc = WSAStartup(MAKEWORD(2, 0), &wsadata);
    if(rc) {
        fprintf(stderr, "WSAStartup failed with error: %d\n", rc);
        return 1;
    }
#endif

    if(argc > 1) {
        hostaddr = inet_addr(argv[1]);
    }
    else {
        hostaddr = htonl(0x7F000001);
    }
    if(argc > 2) {
        username = argv[2];
    }
    if(argc > 3) {
        password = argv[3];
    }
    if(argc > 4) {
        loclfile = argv[4];
    }
    if(argc > 5) {
        scppath = argv[5];
    }

    rc = libssh2_init(0);
    if(rc) {
        fprintf(stderr, "libssh2 initialization failed (%d)\n", rc);
        return 1;
    }

    local = fopen(loclfile, "rb");
    if(!local) {
        fprintf(stderr, "Cannot open local file %s\n", loclfile);
        return 1;
    }

    stat(loclfile, &fileinfo);

    /* Ultra basic "connect to port 22 on localhost".  Your code is
     * responsible for creating the socket establishing the connection
     */
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if(sock == LIBSSH2_INVALID_SOCKET) {
        fprintf(stderr, "failed to create socket.\n");
        goto shutdown;
    }

    sin.sin_family = AF_INET;
    sin.sin_port = htons(22);
    sin.sin_addr.s_addr = hostaddr;
    if(connect(sock, (struct sockaddr*)(&sin), sizeof(struct sockaddr_in))) {
        fprintf(stderr, "failed to connect.\n");
        goto shutdown;
    }

    /* Create a session instance */
    session = libssh2_session_init();
    if(!session) {
        fprintf(stderr, "Could not initialize SSH session.\n");
        goto shutdown;
    }

    /* ... start it up. This will trade welcome banners, exchange keys,
     * and setup crypto, compression, and MAC layers
     */
    rc = libssh2_session_handshake(session, sock);
    if(rc) {
        fprintf(stderr, "Failure establishing SSH session: %d\n", rc);
        goto shutdown;
    }

    /* At this point we have not yet authenticated.  The first thing to do
     * is check the hostkey's fingerprint against our known hosts Your app
     * may have it hard coded, may go to a file, may present it to the
     * user, that's your call
     */
    fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
    fprintf(stderr, "Fingerprint: ");
    for(i = 0; i < 20; i++) {
        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
    }
    fprintf(stderr, "\n");

    if(auth_pw) {
        /* We could authenticate via password */
        if(libssh2_userauth_password(session, username, password)) {
            fprintf(stderr, "Authentication by password failed.\n");
            goto shutdown;
        }
    }
    else {
        /* Or by public key */
        if(libssh2_userauth_publickey_fromfile(session, username,
                                               pubkey, privkey,
                                               password)) {
            fprintf(stderr, "Authentication by public key failed.\n");
            goto shutdown;
        }
    }

    /* Send a file via scp. The mode parameter must only have permissions! */
    channel = libssh2_scp_send(session, scppath, fileinfo.st_mode & 0777,
                               (size_t)fileinfo.st_size);

    if(!channel) {
        char *errmsg;
        int errlen;
        int err;
        err = libssh2_session_last_error(session, &errmsg, &errlen, 0);
        fprintf(stderr, "Unable to open a session: (%d) %s\n", err, errmsg);
        goto shutdown;
    }

    fprintf(stderr, "SCP session waiting to send file\n");
    do {
        nread = fread(mem, 1, sizeof(mem), local);
        if(nread <= 0) {
            /* end of file */
            break;
        }
        ptr = mem;

        do {
            ssize_t nwritten;
            /* write the same data over and over, until error or completion */
            nwritten = libssh2_channel_write(channel, ptr, nread);
            if(nwritten < 0) {
                fprintf(stderr, "ERROR %ld\n", (long)nwritten);
                break;
            }
            else {
                /* nwritten indicates how many bytes were written this time */
                ptr += nwritten;
                nread -= (size_t)nwritten;
            }
        } while(nread);
    } while(1);

    fprintf(stderr, "Sending EOF\n");
    libssh2_channel_send_eof(channel);

    fprintf(stderr, "Waiting for EOF\n");
    libssh2_channel_wait_eof(channel);

    fprintf(stderr, "Waiting for channel to close\n");
    libssh2_channel_wait_closed(channel);

    libssh2_channel_free(channel);
    channel = NULL;

shutdown:

    if(session) {
        libssh2_session_disconnect(session, "Normal Shutdown");
        libssh2_session_free(session);
    }

    if(sock != LIBSSH2_INVALID_SOCKET) {
        shutdown(sock, 2);
        LIBSSH2_SOCKET_CLOSE(sock);
    }

    if(local)
        fclose(local);

    fprintf(stderr, "all done\n");

    libssh2_exit();

#ifdef _WIN32
    WSACleanup();
#endif

    return 0;
}
