libssh2

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/* Copyright (C) The libssh2 project and its contributors.
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 *
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 * Sample doing an SFTP directory listing.
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 *
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 * The sample code has default values for host name, user name, password and
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 * path, but you can specify them on the command line like:
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 *
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 * $ ./sftpdir 192.168.0.1 user password /tmp/secretdir
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 *
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 * SPDX-License-Identifier: BSD-3-Clause
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 */
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#include "libssh2_setup.h"
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#include <libssh2.h>
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#include <libssh2_sftp.h>
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#ifdef HAVE_SYS_SOCKET_H
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#include <sys/socket.h>
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#endif
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#ifdef HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#ifdef HAVE_NETINET_IN_H
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#include <netinet/in.h>
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#endif
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#ifdef HAVE_ARPA_INET_H
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#include <arpa/inet.h>
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#endif
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#include <stdio.h>
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#include <string.h>
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#if defined(_MSC_VER)
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#define LIBSSH2_FILESIZE_MASK "I64u"
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#else
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#define LIBSSH2_FILESIZE_MASK "llu"
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#endif
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static const char *pubkey = "/home/username/.ssh/id_rsa.pub";
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static const char *privkey = "/home/username/.ssh/id_rsa";
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static const char *username = "username";
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static const char *password = "password";
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static const char *sftppath = "/tmp/secretdir";
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static void kbd_callback(const char *name, int name_len,
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                         const char *instruction, int instruction_len,
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                         int num_prompts,
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                         const LIBSSH2_USERAUTH_KBDINT_PROMPT *prompts,
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                         LIBSSH2_USERAUTH_KBDINT_RESPONSE *responses,
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                         void **abstract)
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{
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    (void)name;
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    (void)name_len;
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    (void)instruction;
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    (void)instruction_len;
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    if(num_prompts == 1) {
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        responses[0].text = strdup(password);
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        responses[0].length = (unsigned int)strlen(password);
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    }
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    (void)prompts;
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    (void)abstract;
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} /* kbd_callback */
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int main(int argc, char *argv[])
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{
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    uint32_t hostaddr;
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    libssh2_socket_t sock;
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    int i, auth_pw = 0;
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    struct sockaddr_in sin;
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    const char *fingerprint;
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    char *userauthlist;
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    int rc;
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    LIBSSH2_SESSION *session = NULL;
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    LIBSSH2_SFTP *sftp_session;
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    LIBSSH2_SFTP_HANDLE *sftp_handle;
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#ifdef _WIN32
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    WSADATA wsadata;
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    rc = WSAStartup(MAKEWORD(2, 0), &wsadata);
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    if(rc) {
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        fprintf(stderr, "WSAStartup failed with error: %d\n", rc);
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        return 1;
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    }
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#endif
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    if(argc > 1) {
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        hostaddr = inet_addr(argv[1]);
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    }
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    else {
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        hostaddr = htonl(0x7F000001);
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    }
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    if(argc > 2) {
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        username = argv[2];
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    }
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    if(argc > 3) {
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        password = argv[3];
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    }
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    if(argc > 4) {
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        sftppath = argv[4];
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    }
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    rc = libssh2_init(0);
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    if(rc) {
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        fprintf(stderr, "libssh2 initialization failed (%d)\n", rc);
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        return 1;
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    }
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    /*
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     * The application code is responsible for creating the socket
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     * and establishing the connection
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     */
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    sock = socket(AF_INET, SOCK_STREAM, 0);
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    if(sock == LIBSSH2_INVALID_SOCKET) {
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        fprintf(stderr, "failed to create socket.\n");
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        goto shutdown;
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    }
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    sin.sin_family = AF_INET;
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    sin.sin_port = htons(22);
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    sin.sin_addr.s_addr = hostaddr;
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    if(connect(sock, (struct sockaddr*)(&sin), sizeof(struct sockaddr_in))) {
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        fprintf(stderr, "failed to connect.\n");
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        goto shutdown;
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    }
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    /* Create a session instance */
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    session = libssh2_session_init();
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    if(!session) {
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        fprintf(stderr, "Could not initialize SSH session.\n");
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        goto shutdown;
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    }
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    /* ... start it up. This will trade welcome banners, exchange keys,
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     * and setup crypto, compression, and MAC layers
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     */
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    rc = libssh2_session_handshake(session, sock);
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    if(rc) {
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        fprintf(stderr, "Failure establishing SSH session: %d\n", rc);
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        goto shutdown;
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    }
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    /* At this point we have not yet authenticated.  The first thing to do
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     * is check the hostkey's fingerprint against our known hosts Your app
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     * may have it hard coded, may go to a file, may present it to the
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     * user, that's your call
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     */
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    fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
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    fprintf(stderr, "Fingerprint: ");
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    for(i = 0; i < 20; i++) {
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        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
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    }
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    fprintf(stderr, "\n");
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    /* check what authentication methods are available */
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    userauthlist = libssh2_userauth_list(session, username,
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                                         (unsigned int)strlen(username));
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    if(userauthlist) {
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        fprintf(stderr, "Authentication methods: %s\n", userauthlist);
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        if(strstr(userauthlist, "password")) {
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            auth_pw |= 1;
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        }
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        if(strstr(userauthlist, "keyboard-interactive")) {
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            auth_pw |= 2;
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        }
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        if(strstr(userauthlist, "publickey")) {
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            auth_pw |= 4;
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        }
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        /* check for options */
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        if(argc > 5) {
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            if((auth_pw & 1) && !strcmp(argv[5], "-p")) {
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                auth_pw = 1;
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            }
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            if((auth_pw & 2) && !strcmp(argv[5], "-i")) {
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                auth_pw = 2;
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            }
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            if((auth_pw & 4) && !strcmp(argv[5], "-k")) {
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                auth_pw = 4;
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            }
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        }
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        if(auth_pw & 1) {
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            /* We could authenticate via password */
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            if(libssh2_userauth_password(session, username, password)) {
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                fprintf(stderr, "Authentication by password failed.\n");
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                goto shutdown;
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            }
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        }
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        else if(auth_pw & 2) {
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            /* Or via keyboard-interactive */
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            if(libssh2_userauth_keyboard_interactive(session, username,
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                                                     &kbd_callback) ) {
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                fprintf(stderr,
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                        "Authentication by keyboard-interactive failed.\n");
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                goto shutdown;
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            }
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            else {
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                fprintf(stderr,
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                        "Authentication by keyboard-interactive succeeded.\n");
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            }
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        }
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        else if(auth_pw & 4) {
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            /* Or by public key */
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            if(libssh2_userauth_publickey_fromfile(session, username,
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                                                   pubkey, privkey,
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                                                   password)) {
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                fprintf(stderr, "Authentication by public key failed.\n");
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                goto shutdown;
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            }
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            else {
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                fprintf(stderr, "Authentication by public key succeeded.\n");
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            }
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        }
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        else {
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            fprintf(stderr, "No supported authentication methods found.\n");
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            goto shutdown;
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        }
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    }
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    fprintf(stderr, "libssh2_sftp_init().\n");
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    sftp_session = libssh2_sftp_init(session);
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    if(!sftp_session) {
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        fprintf(stderr, "Unable to init SFTP session\n");
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        goto shutdown;
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    }
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    /* Since we have not set non-blocking, tell libssh2 we are blocking */
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    libssh2_session_set_blocking(session, 1);
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    fprintf(stderr, "libssh2_sftp_opendir().\n");
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    /* Request a dir listing via SFTP */
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    sftp_handle = libssh2_sftp_opendir(sftp_session, sftppath);
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    if(!sftp_handle) {
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        fprintf(stderr, "Unable to open dir with SFTP\n");
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        goto shutdown;
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    }
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    fprintf(stderr, "libssh2_sftp_opendir() is done, now receive listing.\n");
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    do {
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        char mem[512];
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        char longentry[512];
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        LIBSSH2_SFTP_ATTRIBUTES attrs;
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        /* loop until we fail */
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        rc = libssh2_sftp_readdir_ex(sftp_handle, mem, sizeof(mem),
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                                     longentry, sizeof(longentry), &attrs);
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        if(rc > 0) {
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            /* rc is the length of the file name in the mem
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               buffer */
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            if(longentry[0] != '\0') {
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                printf("%s\n", longentry);
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            }
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            else {
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                if(attrs.flags & LIBSSH2_SFTP_ATTR_PERMISSIONS) {
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                    /* this should check what permissions it
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                       is and print the output accordingly */
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                    printf("--fix----- ");
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                }
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                else {
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                    printf("---------- ");
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                }
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                if(attrs.flags & LIBSSH2_SFTP_ATTR_UIDGID) {
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                    printf("%4d %4d ", (int) attrs.uid, (int) attrs.gid);
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                }
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                else {
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                    printf("   -    - ");
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                }
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                if(attrs.flags & LIBSSH2_SFTP_ATTR_SIZE) {
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                    printf("%8" LIBSSH2_FILESIZE_MASK " ", attrs.filesize);
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                }
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                printf("%s\n", mem);
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            }
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        }
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        else {
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            break;
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        }
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    } while(1);
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    libssh2_sftp_closedir(sftp_handle);
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    libssh2_sftp_shutdown(sftp_session);
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shutdown:
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291
    if(session) {
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        libssh2_session_disconnect(session, "Normal Shutdown");
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        libssh2_session_free(session);
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    }
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296
    if(sock != LIBSSH2_INVALID_SOCKET) {
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        shutdown(sock, 2);
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        LIBSSH2_SOCKET_CLOSE(sock);
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    }
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301
    fprintf(stderr, "all done\n");
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303
    libssh2_exit();
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305
#ifdef _WIN32
306
    WSACleanup();
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#endif
308

309
    return 0;
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}
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