auth.h

/*
 * Dropbear - a SSH2 server
 *
 * Copyright (c) 2002,2003 Matt Johnston
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. */

#ifndef DROPBEAR_AUTH_H_
#define DROPBEAR_AUTH_H_

#include "includes.h"
#include "signkey.h"
#include "chansession.h"

void svr_authinitialise(void);
void cli_authinitialise(void);

/* Server functions */
void recv_msg_userauth_request(void);
void send_msg_userauth_failure(int partial, int incrfail);
void send_msg_userauth_success(void);
void send_msg_userauth_banner(buffer *msg);
void svr_auth_password(void);
void svr_auth_pubkey(void);
void svr_auth_pam(void);

#ifdef ENABLE_SVR_PUBKEY_OPTIONS
int svr_pubkey_allows_agentfwd(void);
int svr_pubkey_allows_tcpfwd(void);
int svr_pubkey_allows_x11fwd(void);
int svr_pubkey_allows_pty(void);
void svr_pubkey_set_forced_command(struct ChanSess *chansess);
void svr_pubkey_options_cleanup(void);
int svr_add_pubkey_options(buffer *options_buf, int line_num,
                           const char *filename);
#else
/* no option : success */
#define svr_pubkey_allows_agentfwd() 1
#define svr_pubkey_allows_tcpfwd() 1
#define svr_pubkey_allows_x11fwd() 1
#define svr_pubkey_allows_pty() 1
static inline void svr_pubkey_set_forced_command(struct ChanSess *chansess) {}
static inline void svr_pubkey_options_cleanup(void) {}
#define svr_add_pubkey_options(x, y, z) DROPBEAR_SUCCESS
#endif

/* Client functions */
void recv_msg_userauth_failure(void);
void recv_msg_userauth_success(void);
void recv_msg_userauth_specific_60(void);
void recv_msg_userauth_pk_ok(void);
void recv_msg_userauth_info_request(void);
void cli_get_user(void);
void cli_auth_getmethods(void);
int cli_auth_try(void);
void recv_msg_userauth_banner(void);
void cli_pubkeyfail(void);
void cli_auth_password(void);
int cli_auth_pubkey(void);
void cli_auth_interactive(void);
char *getpass_or_cancel(char *prompt);
void cli_auth_pubkey_cleanup(void);

#define MAX_USERNAME_LEN 25 /* arbitrary for the moment */

#define AUTH_TYPE_NONE 1
#define AUTH_TYPE_PUBKEY (1 << 1)
#define AUTH_TYPE_PASSWORD (1 << 2)
#define AUTH_TYPE_INTERACT (1 << 3)

#define AUTH_METHOD_NONE "none"
#define AUTH_METHOD_NONE_LEN 4
#define AUTH_METHOD_PUBKEY "publickey"
#define AUTH_METHOD_PUBKEY_LEN 9
#define AUTH_METHOD_PASSWORD "password"
#define AUTH_METHOD_PASSWORD_LEN 8
#define AUTH_METHOD_INTERACT "keyboard-interactive"
#define AUTH_METHOD_INTERACT_LEN 20

/* This structure is shared between server and client - it contains
 * relatively little extraneous bits when used for the client rather than the
 * server */
struct AuthState {
  char
      *username; /* This is the username the client presents to check. It
                                    is updated each run through, used for auth
                    checking */
  unsigned char authtypes; /* Flags indicating which auth types are still
                                                          valid */
  unsigned int failcount;  /* Number of (failed) authentication attempts.*/
  unsigned authdone : 1;   /* 0 if we haven't authed, 1 if we have. Applies for
                                                      client and server (though
                              has differing
                                                      meanings). */
  unsigned perm_warn : 1;  /* Server only, set if bad permissions on
                                                      ~/.ssh/authorized_keys have
                              already been
                                                      logged. */

  /* These are only used for the server */
  uid_t pw_uid;
  gid_t pw_gid;
  char *pw_dir;
  char *pw_shell;
  char *pw_name;
  char *pw_passwd;
#ifdef ENABLE_SVR_PUBKEY_OPTIONS
  struct PubKeyOptions *pubkey_options;
#endif
};

#ifdef ENABLE_SVR_PUBKEY_OPTIONS
struct PubKeyOptions;
struct PubKeyOptions {
  /* Flags */
  int no_port_forwarding_flag;
  int no_agent_forwarding_flag;
  int no_x11_forwarding_flag;
  int no_pty_flag;
  /* "command=" option. */
  char *forced_command;
};
#endif

#endif /* DROPBEAR_AUTH_H_ */