463 lines
15 KiB
C
463 lines
15 KiB
C
/* $NetBSD: ssh.h,v 1.2 2000/10/05 14:09:08 sommerfeld Exp $ */
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/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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*
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* Generic header file for ssh.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*/
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/* from OpenBSD: ssh.h,v 1.51 2000/09/12 20:53:10 markus Exp */
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#ifndef SSH_H
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#define SSH_H
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#include "rsa.h"
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#include "cipher.h"
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/*
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* XXX
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* The default cipher used if IDEA is not supported by the remote host. It is
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* recommended that this be one of the mandatory ciphers (DES, 3DES), though
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* that is not required.
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*/
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#define SSH_FALLBACK_CIPHER SSH_CIPHER_3DES
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/* Cipher used for encrypting authentication files. */
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#define SSH_AUTHFILE_CIPHER SSH_CIPHER_3DES
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/* Default port number. */
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#define SSH_DEFAULT_PORT 22
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/* Maximum number of TCP/IP ports forwarded per direction. */
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#define SSH_MAX_FORWARDS_PER_DIRECTION 100
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/*
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* Maximum number of RSA authentication identity files that can be specified
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* in configuration files or on the command line.
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*/
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#define SSH_MAX_IDENTITY_FILES 100
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/*
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* Major protocol version. Different version indicates major incompatiblity
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* that prevents communication.
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*
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* Minor protocol version. Different version indicates minor incompatibility
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* that does not prevent interoperation.
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*/
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#define PROTOCOL_MAJOR_1 1
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#define PROTOCOL_MINOR_1 5
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/* We support both SSH1 and SSH2 */
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#define PROTOCOL_MAJOR_2 2
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#define PROTOCOL_MINOR_2 0
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/*
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* Name for the service. The port named by this service overrides the
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* default port if present.
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*/
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#define SSH_SERVICE_NAME "ssh"
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/*
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* Name of the environment variable containing the pathname of the
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* authentication socket.
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*/
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#define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK"
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/*
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* Name of the environment variable containing the pathname of the
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* authentication socket.
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*/
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#define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID"
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/*
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* environment variable for overwriting the default ssh-askpass location
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*/
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#define SSH_ASKPASS_ENV "SSH_ASKPASS"
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/*
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* Force host key length and server key length to differ by at least this
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* many bits. This is to make double encryption with rsaref work.
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*/
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#define SSH_KEY_BITS_RESERVED 128
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/*
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* Length of the session key in bytes. (Specified as 256 bits in the
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* protocol.)
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*/
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#define SSH_SESSION_KEY_LENGTH 32
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/* Name of Kerberos service for SSH to use. */
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#define KRB4_SERVICE_NAME "rcmd"
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/*
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* Authentication methods. New types can be added, but old types should not
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* be removed for compatibility. The maximum allowed value is 31.
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*/
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#define SSH_AUTH_RHOSTS 1
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#define SSH_AUTH_RSA 2
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#define SSH_AUTH_PASSWORD 3
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#define SSH_AUTH_RHOSTS_RSA 4
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#define SSH_AUTH_TIS 5
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#define SSH_AUTH_KERBEROS 6
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#define SSH_PASS_KERBEROS_TGT 7
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/* 8 to 15 are reserved */
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#define SSH_PASS_AFS_TOKEN 21
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/* Protocol flags. These are bit masks. */
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#define SSH_PROTOFLAG_SCREEN_NUMBER 1 /* X11 forwarding includes screen */
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#define SSH_PROTOFLAG_HOST_IN_FWD_OPEN 2 /* forwarding opens contain host */
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/*
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* Definition of message types. New values can be added, but old values
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* should not be removed or without careful consideration of the consequences
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* for compatibility. The maximum value is 254; value 255 is reserved for
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* future extension.
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*/
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/* Message name */ /* msg code */ /* arguments */
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#define SSH_MSG_NONE 0 /* no message */
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#define SSH_MSG_DISCONNECT 1 /* cause (string) */
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#define SSH_SMSG_PUBLIC_KEY 2 /* ck,msk,srvk,hostk */
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#define SSH_CMSG_SESSION_KEY 3 /* key (BIGNUM) */
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#define SSH_CMSG_USER 4 /* user (string) */
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#define SSH_CMSG_AUTH_RHOSTS 5 /* user (string) */
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#define SSH_CMSG_AUTH_RSA 6 /* modulus (BIGNUM) */
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#define SSH_SMSG_AUTH_RSA_CHALLENGE 7 /* int (BIGNUM) */
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#define SSH_CMSG_AUTH_RSA_RESPONSE 8 /* int (BIGNUM) */
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#define SSH_CMSG_AUTH_PASSWORD 9 /* pass (string) */
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#define SSH_CMSG_REQUEST_PTY 10 /* TERM, tty modes */
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#define SSH_CMSG_WINDOW_SIZE 11 /* row,col,xpix,ypix */
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#define SSH_CMSG_EXEC_SHELL 12 /* */
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#define SSH_CMSG_EXEC_CMD 13 /* cmd (string) */
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#define SSH_SMSG_SUCCESS 14 /* */
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#define SSH_SMSG_FAILURE 15 /* */
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#define SSH_CMSG_STDIN_DATA 16 /* data (string) */
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#define SSH_SMSG_STDOUT_DATA 17 /* data (string) */
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#define SSH_SMSG_STDERR_DATA 18 /* data (string) */
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#define SSH_CMSG_EOF 19 /* */
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#define SSH_SMSG_EXITSTATUS 20 /* status (int) */
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#define SSH_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* channel (int) */
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#define SSH_MSG_CHANNEL_OPEN_FAILURE 22 /* channel (int) */
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#define SSH_MSG_CHANNEL_DATA 23 /* ch,data (int,str) */
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#define SSH_MSG_CHANNEL_CLOSE 24 /* channel (int) */
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#define SSH_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* channel (int) */
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/* SSH_CMSG_X11_REQUEST_FORWARDING 26 OBSOLETE */
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#define SSH_SMSG_X11_OPEN 27 /* channel (int) */
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#define SSH_CMSG_PORT_FORWARD_REQUEST 28 /* p,host,hp (i,s,i) */
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#define SSH_MSG_PORT_OPEN 29 /* ch,h,p (i,s,i) */
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#define SSH_CMSG_AGENT_REQUEST_FORWARDING 30 /* */
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#define SSH_SMSG_AGENT_OPEN 31 /* port (int) */
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#define SSH_MSG_IGNORE 32 /* string */
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#define SSH_CMSG_EXIT_CONFIRMATION 33 /* */
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#define SSH_CMSG_X11_REQUEST_FORWARDING 34 /* proto,data (s,s) */
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#define SSH_CMSG_AUTH_RHOSTS_RSA 35 /* user,mod (s,mpi) */
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#define SSH_MSG_DEBUG 36 /* string */
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#define SSH_CMSG_REQUEST_COMPRESSION 37 /* level 1-9 (int) */
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#define SSH_CMSG_MAX_PACKET_SIZE 38 /* size 4k-1024k
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(int) */
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/*
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* The protocol defines this message as support for the
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* TIS authentication server. However, we currently use
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* it for s/key challenge/response.
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* XXX We should bring this up on secsh. --thorpej
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*/
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#define SSH_CMSG_AUTH_TIS 39 /* */
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#define SSH_SMSG_AUTH_TIS_CHALLENGE 40 /* challenge (string) */
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#define SSH_CMSG_AUTH_TIS_RESPONSE 41 /* response (string) */
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#define SSH_CMSG_AUTH_KERBEROS 42 /* (KTEXT) */
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#define SSH_SMSG_AUTH_KERBEROS_RESPONSE 43 /* (KTEXT) */
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#define SSH_CMSG_HAVE_KERBEROS_TGT 44 /* credentials (s) */
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/* Reserved for official extensions. */
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#define SSH_CMSG_RESERVED_START 45
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#define SSH_CMSG_RESERVED_END 63
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#define SSH_CMSG_HAVE_AFS_TOKEN 65 /* token (s) */
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/*------------ definitions for login.c -------------*/
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/*
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* Returns the time when the user last logged in. Returns 0 if the
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* information is not available. This must be called before record_login.
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* The host from which the user logged in is stored in buf.
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*/
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unsigned long
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get_last_login_time(uid_t uid, const char *logname,
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char *buf, unsigned int bufsize);
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/*
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* Records that the user has logged in. This does many things normally done
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* by login(1).
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*/
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void
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record_login(pid_t pid, const char *ttyname, const char *user, uid_t uid,
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const char *host, struct sockaddr *addr);
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/*
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* Records that the user has logged out. This does many thigs normally done
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* by login(1) or init.
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*/
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void record_logout(pid_t pid, const char *ttyname);
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/*------------ definitions for sshconnect.c ----------*/
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/*
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* Opens a TCP/IP connection to the remote server on the given host. If port
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* is 0, the default port will be used. If anonymous is zero, a privileged
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* port will be allocated to make the connection. This requires super-user
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* privileges if anonymous is false. Connection_attempts specifies the
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* maximum number of tries, one per second. This returns true on success,
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* and zero on failure. If the connection is successful, this calls
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* packet_set_connection for the connection.
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*/
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int
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ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
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u_short port, int connection_attempts,
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int anonymous, uid_t original_real_uid,
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const char *proxy_command);
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/*
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* Starts a dialog with the server, and authenticates the current user on the
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* server. This does not need any extra privileges. The basic connection to
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* the server must already have been established before this is called. If
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* login fails, this function prints an error and never returns. This
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* initializes the random state, and leaves it initialized (it will also have
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* references from the packet module).
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*/
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void
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ssh_login(int host_key_valid, RSA * host_key, const char *host,
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struct sockaddr * hostaddr, uid_t original_real_uid);
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/*------------ Definitions for various authentication methods. -------*/
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/*
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* Tries to authenticate the user using the .rhosts file. Returns true if
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* authentication succeeds. If ignore_rhosts is non-zero, this will not
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* consider .rhosts and .shosts (/etc/hosts.equiv will still be used).
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*/
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int auth_rhosts(struct passwd * pw, const char *client_user);
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/*
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* Tries to authenticate the user using the .rhosts file and the host using
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* its host key. Returns true if authentication succeeds.
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*/
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int
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auth_rhosts_rsa(struct passwd * pw, const char *client_user, RSA* client_host_key);
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/*
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* Tries to authenticate the user using password. Returns true if
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* authentication succeeds.
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*/
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int auth_password(struct passwd * pw, const char *password);
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/*
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* Performs the RSA authentication dialog with the client. This returns 0 if
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* the client could not be authenticated, and 1 if authentication was
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* successful. This may exit if there is a serious protocol violation.
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*/
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int auth_rsa(struct passwd * pw, BIGNUM * client_n);
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/*
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* Parses an RSA key (number of bits, e, n) from a string. Moves the pointer
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* over the key. Skips any whitespace at the beginning and at end.
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*/
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int auth_rsa_read_key(char **cpp, unsigned int *bitsp, BIGNUM * e, BIGNUM * n);
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/*
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* Returns the name of the machine at the other end of the socket. The
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* returned string should be freed by the caller.
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*/
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char *get_remote_hostname(int socket);
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/*
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* Return the canonical name of the host in the other side of the current
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* connection (as returned by packet_get_connection). The host name is
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* cached, so it is efficient to call this several times.
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*/
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const char *get_canonical_hostname(void);
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/*
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* Returns the remote IP address as an ascii string. The value need not be
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* freed by the caller.
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*/
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const char *get_remote_ipaddr(void);
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/* Returns the port number of the peer of the socket. */
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int get_peer_port(int sock);
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/* Returns the port number of the remote/local host. */
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int get_remote_port(void);
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int get_local_port(void);
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/*
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* Performs the RSA authentication challenge-response dialog with the client,
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* and returns true (non-zero) if the client gave the correct answer to our
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* challenge; returns zero if the client gives a wrong answer.
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*/
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int auth_rsa_challenge_dialog(RSA *pk);
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/*
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* Reads a passphrase from /dev/tty with echo turned off. Returns the
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* passphrase (allocated with xmalloc). Exits if EOF is encountered. If
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* from_stdin is true, the passphrase will be read from stdin instead.
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*/
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char *read_passphrase(const char *prompt, int from_stdin);
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/*------------ Definitions for logging. -----------------------*/
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/* Supported syslog facilities and levels. */
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typedef enum {
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SYSLOG_FACILITY_DAEMON,
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SYSLOG_FACILITY_USER,
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SYSLOG_FACILITY_AUTH,
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SYSLOG_FACILITY_LOCAL0,
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SYSLOG_FACILITY_LOCAL1,
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SYSLOG_FACILITY_LOCAL2,
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SYSLOG_FACILITY_LOCAL3,
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SYSLOG_FACILITY_LOCAL4,
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SYSLOG_FACILITY_LOCAL5,
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SYSLOG_FACILITY_LOCAL6,
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SYSLOG_FACILITY_LOCAL7
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} SyslogFacility;
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typedef enum {
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SYSLOG_LEVEL_QUIET,
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SYSLOG_LEVEL_FATAL,
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SYSLOG_LEVEL_ERROR,
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SYSLOG_LEVEL_INFO,
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SYSLOG_LEVEL_VERBOSE,
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SYSLOG_LEVEL_DEBUG1,
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SYSLOG_LEVEL_DEBUG2,
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SYSLOG_LEVEL_DEBUG3
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} LogLevel;
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/* Initializes logging. */
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void log_init(const char *av0, LogLevel level, SyslogFacility facility,
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int on_stderr, int quiet_mode, int debug_mode);
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/* Logging implementation, depending on server or client */
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void do_log(LogLevel level, const char *fmt, va_list args)
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__attribute__((format(printf, 2, 0)));
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/* name to facility/level */
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SyslogFacility log_facility_number(const char *name);
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LogLevel log_level_number(const char *name);
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/* Output a message to syslog or stderr */
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void fatal(const char *fmt,...) __attribute__((format(printf, 1, 2)));
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void error(const char *fmt,...) __attribute__((format(printf, 1, 2)));
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void log(const char *fmt,...) __attribute__((format(printf, 1, 2)));
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void verbose(const char *fmt,...) __attribute__((format(printf, 1, 2)));
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void debug(const char *fmt,...) __attribute__((format(printf, 1, 2)));
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void debug2(const char *fmt,...) __attribute__((format(printf, 1, 2)));
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void debug3(const char *fmt,...) __attribute__((format(printf, 1, 2)));
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/* same as fatal() but w/o logging */
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void fatal_cleanup(void);
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/*
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* Registers a cleanup function to be called by fatal()/fatal_cleanup()
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* before exiting. It is permissible to call fatal_remove_cleanup for the
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* function itself from the function.
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*/
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void fatal_add_cleanup(void (*proc) (void *context), void *context);
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/* Removes a cleanup function to be called at fatal(). */
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void fatal_remove_cleanup(void (*proc) (void *context), void *context);
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/* ---- misc */
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/*
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* Expands tildes in the file name. Returns data allocated by xmalloc.
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* Warning: this calls getpw*.
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*/
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char *tilde_expand_filename(const char *filename, uid_t my_uid);
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/* remove newline at end of string */
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char *chop(char *s);
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/* return next token in configuration line */
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char *strdelim(char **s);
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/* set filedescriptor to non-blocking */
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void set_nonblock(int fd);
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/*
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* Performs the interactive session. This handles data transmission between
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* the client and the program. Note that the notion of stdin, stdout, and
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* stderr in this function is sort of reversed: this function writes to stdin
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* (of the child program), and reads from stdout and stderr (of the child
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* program).
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*/
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void server_loop(pid_t pid, int fdin, int fdout, int fderr);
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void server_loop2(void);
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/* Client side main loop for the interactive session. */
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int client_loop(int have_pty, int escape_char, int id);
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/* Linked list of custom environment strings (see auth-rsa.c). */
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struct envstring {
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struct envstring *next;
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char *s;
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};
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/*
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* `Atomic' read and write operations, to ensure that all the
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* data makes it through a socket (handles signals, etc.).
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*/
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ssize_t atomic_read(int, void *, size_t);
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ssize_t atomic_write(int, const void *, size_t);
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/*
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* Misc. random functions.
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*/
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void ssh_random_stir(void);
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#ifdef KRB4
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#include <krb.h>
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/*
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* Performs Kerberos v4 mutual authentication with the client. This returns 0
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* if the client could not be authenticated, and 1 if authentication was
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* successful. This may exit if there is a serious protocol violation.
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*/
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int auth_krb4(const char *server_user, KTEXT auth, char **client);
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int krb4_init(uid_t uid);
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void krb4_cleanup_proc(void *ignore);
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int auth_krb4_password(struct passwd * pw, const char *password);
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#ifdef AFS
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#include <kafs.h>
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/* Accept passed Kerberos v4 ticket-granting ticket and AFS tokens. */
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int auth_kerberos_tgt(struct passwd * pw, const char *string);
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int auth_afs_token(struct passwd * pw, const char *token_string);
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int creds_to_radix(CREDENTIALS * creds, unsigned char *buf, size_t buflen);
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int radix_to_creds(const char *buf, CREDENTIALS * creds);
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#endif /* AFS */
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#endif /* KRB4 */
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#ifdef SKEY
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#include <skey.h>
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char *skey_fake_keyinfo(const char *username);
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int auth_skey_password(struct passwd *pw, const char *password);
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#endif /* SKEY */
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/* AF_UNSPEC or AF_INET or AF_INET6 */
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extern int IPv4or6;
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#endif /* SSH_H */
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