text: #ifndef HEADER_CURL_SSH_H
  #define HEADER_CURL_SSH_H
  /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
   *
   * This software is licensed as described in the file COPYING, which
   * you should have received as part of this distribution. The terms
   * are also available at https://curl.haxx.se/docs/copyright.html.
   *
   * You may opt to use, copy, modify, merge, publish, distribute and/or sell
   * copies of the Software, and permit persons to whom the Software is
   * furnished to do so, under the terms of the COPYING file.
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   * KIND, either express or implied.
   *
   ***************************************************************************/
  
  #include "curl_setup.h"
  
  #if defined(HAVE_LIBSSH2_H)
  #include <libssh2.h>
  #include <libssh2_sftp.h>
  #elif defined(HAVE_LIBSSH_LIBSSH_H)
  #include <libssh/libssh.h>
  #include <libssh/sftp.h>
  #endif /* HAVE_LIBSSH2_H */
  
  /****************************************************************************
   * SSH unique setup
   ***************************************************************************/
  typedef enum {
    SSH_NO_STATE = -1,  /* Used for "nextState" so say there is none */
    SSH_STOP = 0,       /* do nothing state, stops the state machine */
  
    SSH_INIT,           /* First state in SSH-CONNECT */
    SSH_S_STARTUP,      /* Session startup */
    SSH_HOSTKEY,        /* verify hostkey */
    SSH_AUTHLIST,
    SSH_AUTH_PKEY_INIT,
    SSH_AUTH_PKEY,
    SSH_AUTH_PASS_INIT,
    SSH_AUTH_PASS,
    SSH_AUTH_AGENT_INIT, /* initialize then wait for connection to agent */
    SSH_AUTH_AGENT_LIST, /* ask for list then wait for entire list to come */
    SSH_AUTH_AGENT,      /* attempt one key at a time */
    SSH_AUTH_HOST_INIT,
    SSH_AUTH_HOST,
    SSH_AUTH_KEY_INIT,
    SSH_AUTH_KEY,
    SSH_AUTH_GSSAPI,
    SSH_AUTH_DONE,
    SSH_SFTP_INIT,
    SSH_SFTP_REALPATH,   /* Last state in SSH-CONNECT */
  
    SSH_SFTP_QUOTE_INIT, /* First state in SFTP-DO */
    SSH_SFTP_POSTQUOTE_INIT, /* (Possibly) First state in SFTP-DONE */
    SSH_SFTP_QUOTE,
    SSH_SFTP_NEXT_QUOTE,
    SSH_SFTP_QUOTE_STAT,
    SSH_SFTP_QUOTE_SETSTAT,
    SSH_SFTP_QUOTE_SYMLINK,
    SSH_SFTP_QUOTE_MKDIR,
    SSH_SFTP_QUOTE_RENAME,
    SSH_SFTP_QUOTE_RMDIR,
    SSH_SFTP_QUOTE_UNLINK,
    SSH_SFTP_QUOTE_STATVFS,
    SSH_SFTP_GETINFO,
    SSH_SFTP_FILETIME,
    SSH_SFTP_TRANS_INIT,
    SSH_SFTP_UPLOAD_INIT,
    SSH_SFTP_CREATE_DIRS_INIT,
    SSH_SFTP_CREATE_DIRS,
    SSH_SFTP_CREATE_DIRS_MKDIR,
    SSH_SFTP_READDIR_INIT,
    SSH_SFTP_READDIR,
    SSH_SFTP_READDIR_LINK,
    SSH_SFTP_READDIR_BOTTOM,
    SSH_SFTP_READDIR_DONE,
    SSH_SFTP_DOWNLOAD_INIT,
    SSH_SFTP_DOWNLOAD_STAT, /* Last state in SFTP-DO */
    SSH_SFTP_CLOSE,    /* Last state in SFTP-DONE */
    SSH_SFTP_SHUTDOWN, /* First state in SFTP-DISCONNECT */
    SSH_SCP_TRANS_INIT, /* First state in SCP-DO */
    SSH_SCP_UPLOAD_INIT,
    SSH_SCP_DOWNLOAD_INIT,
    SSH_SCP_DOWNLOAD,
    SSH_SCP_DONE,
    SSH_SCP_SEND_EOF,
    SSH_SCP_WAIT_EOF,
    SSH_SCP_WAIT_CLOSE,
    SSH_SCP_CHANNEL_FREE,   /* Last state in SCP-DONE */
    SSH_SESSION_DISCONNECT, /* First state in SCP-DISCONNECT */
    SSH_SESSION_FREE,       /* Last state in SCP/SFTP-DISCONNECT */
    SSH_QUIT,
    SSH_LAST  /* never used */
  } sshstate;
  
  /* this struct is used in the HandleData struct which is part of the
     Curl_easy, which means this is used on a per-easy handle basis.
     Everything that is strictly related to a connection is banned from this
     struct. */
  struct SSHPROTO {
    char *path;                  /* the path we operate on */
  };
  
  /* ssh_conn is used for struct connection-oriented data in the connectdata
     struct */
  struct ssh_conn {
    const char *authlist;       /* List of auth. methods, managed by libssh2 */
  
    /* common */
    const char *passphrase;     /* pass-phrase to use */
    char *rsa_pub;              /* path name */
    char *rsa;                  /* path name */
    bool authed;                /* the connection has been authenticated fine */
    sshstate state;             /* always use ssh.c:state() to change state! */
    sshstate nextstate;         /* the state to goto after stopping */
    CURLcode actualcode;        /* the actual error code */
    struct curl_slist *quote_item; /* for the quote option */
    char *quote_path1;          /* two generic pointers for the QUOTE stuff */
    char *quote_path2;
  
    bool acceptfail;            /* used by the SFTP_QUOTE (continue if
                                   quote command fails) */
    char *homedir;              /* when doing SFTP we figure out home dir in the
                                   connect phase */
    size_t readdir_len, readdir_totalLen, readdir_currLen;
    char *readdir_line;
    char *readdir_linkPath;
    /* end of READDIR stuff */
  
    int secondCreateDirs;         /* counter use by the code to see if the
                                     second attempt has been made to change
                                     to/create a directory */
    char *slash_pos;              /* used by the SFTP_CREATE_DIRS state */
  
    int orig_waitfor;             /* default READ/WRITE bits wait for */
  
  #if defined(USE_LIBSSH)
  /* our variables */
    unsigned kbd_state; /* 0 or 1 */
    ssh_key privkey;
    ssh_key pubkey;
    int auth_methods;
    ssh_session ssh_session;
    ssh_scp scp_session;
    sftp_session sftp_session;
    sftp_file sftp_file;
    sftp_dir sftp_dir;
  
    unsigned sftp_recv_state; /* 0 or 1 */
    int sftp_file_index; /* for async read */
    sftp_attributes readdir_attrs; /* used by the SFTP readdir actions */
    sftp_attributes readdir_link_attrs; /* used by the SFTP readdir actions */
    sftp_attributes quote_attrs; /* used by the SFTP_QUOTE state */
  
    const char *readdir_filename; /* points within readdir_attrs */
    const char *readdir_longentry;
    char *readdir_tmp;
  #elif defined(USE_LIBSSH2)
    char *readdir_filename;
    char *readdir_longentry;
  
    LIBSSH2_SFTP_ATTRIBUTES quote_attrs; /* used by the SFTP_QUOTE state */
  
    /* Here's a set of struct members used by the SFTP_READDIR state */
    LIBSSH2_SFTP_ATTRIBUTES readdir_attrs;
    LIBSSH2_SESSION *ssh_session; /* Secure Shell session */
    LIBSSH2_CHANNEL *ssh_channel; /* Secure Shell channel handle */
    LIBSSH2_SFTP *sftp_session;   /* SFTP handle */
    LIBSSH2_SFTP_HANDLE *sftp_handle;
  
  #ifdef HAVE_LIBSSH2_AGENT_API
    LIBSSH2_AGENT *ssh_agent;     /* proxy to ssh-agent/pageant */
    struct libssh2_agent_publickey *sshagent_identity,
                                   *sshagent_prev_identity;
  #endif
  
    /* note that HAVE_LIBSSH2_KNOWNHOST_API is a define set in the libssh2.h
       header */
  #ifdef HAVE_LIBSSH2_KNOWNHOST_API
    LIBSSH2_KNOWNHOSTS *kh;
  #endif
  #endif /* USE_LIBSSH */
  };
  
  #if defined(USE_LIBSSH)
  
  #define CURL_LIBSSH_VERSION ssh_version(0)
  
  extern const struct Curl_handler Curl_handler_scp;
  extern const struct Curl_handler Curl_handler_sftp;
  
  #elif defined(USE_LIBSSH2)
  
  /* Feature detection based on version numbers to better work with
     non-configure platforms */
  
  #if !defined(LIBSSH2_VERSION_NUM) || (LIBSSH2_VERSION_NUM < 0x001000)
  #  error "SCP/SFTP protocols require libssh2 0.16 or later"
  #endif
  
  #if LIBSSH2_VERSION_NUM >= 0x010000
  #define HAVE_LIBSSH2_SFTP_SEEK64 1
  #endif
  
  #if LIBSSH2_VERSION_NUM >= 0x010100
  #define HAVE_LIBSSH2_VERSION 1
  #endif
  
  #if LIBSSH2_VERSION_NUM >= 0x010205
  #define HAVE_LIBSSH2_INIT 1
  #define HAVE_LIBSSH2_EXIT 1
  #endif
  
  #if LIBSSH2_VERSION_NUM >= 0x010206
  #define HAVE_LIBSSH2_KNOWNHOST_CHECKP 1
  #define HAVE_LIBSSH2_SCP_SEND64 1
  #endif
  
  #if LIBSSH2_VERSION_NUM >= 0x010208
  #define HAVE_LIBSSH2_SESSION_HANDSHAKE 1
  #endif
  
  #ifdef HAVE_LIBSSH2_VERSION
  /* get it run-time if possible */
  #define CURL_LIBSSH2_VERSION libssh2_version(0)
  #else
  /* use build-time if run-time not possible */
  #define CURL_LIBSSH2_VERSION LIBSSH2_VERSION
  #endif
  
  extern const struct Curl_handler Curl_handler_scp;
  extern const struct Curl_handler Curl_handler_sftp;
  
  #endif /* USE_LIBSSH2 */
  
  #endif /* HEADER_CURL_SSH_H */
  