env_ami.c

这是用C编写IMAP源代码

  fd_set rfd,efd;
  struct timeval tmo;
  FD_ZERO (&rfd);
  FD_ZERO (&efd);
  FD_SET (0,&rfd);
  FD_SET (0,&efd);
  tmo.tv_sec = seconds; tmo.tv_usec = 0;
  return select (1,&rfd,0,&efd,&tmo) ? LONGT : NIL;
}

/* Return Amiga password entry for user name
 * Accepts: user name string
 * Returns: password entry
 *
 * Tries all-lowercase form of user name if given user name fails
 */

static struct passwd *pwuser (unsigned char *user)
{
  unsigned char *s;
  struct passwd *pw = getpwnam (user);
  if (!pw) {			/* failed, see if any uppercase characters */
    for (s = user; *s && !isupper (*s); s++);
    if (*s) {			/* yes, try all lowercase form */
      pw = getpwnam (s = lcase (cpystr (user)));
      fs_give ((void **) &s);
    }
  }
  return pw;
}


/* Validate password for user name
 * Accepts: user name string
 *	    password string
 *	    argument count
 *	    argument vector
 * Returns: password entry if validated
 *
 * Tries password+1 if password fails and starts with space
 */

static struct passwd *valpwd (char *user,char *pwd,int argc,char *argv[])
{
  char *s;
  struct passwd *pw;
  struct passwd *ret = NIL;
  if (auth_md5.server) {	/* using CRAM-MD5 authentication? */
    if (s = auth_md5_pwd (user)) {
      if (!strcmp (s,pwd) || ((*pwd == ' ') && pwd[1] && !strcmp (s,pwd+1)))
	ret = pwuser (user);	/* validated, get passwd entry for user */
      memset (s,0,strlen (s));	/* erase sensitive information */
      fs_give ((void **) &s);
    }
  }
  else if (pw = pwuser (user)) {/* can get user? */
    s = cpystr (pw->pw_name);	/* copy returned name in case we need it */
    if (*pwd && !(ret = checkpw (pw,pwd,argc,argv)) &&
	(*pwd == ' ') && pwd[1] && (ret = pwuser (s)))
      ret = checkpw (pw,pwd+1,argc,argv);
    fs_give ((void **) &s);	/* don't need copy of name any more */
  }
  return ret;
}

/* Server log in
 * Accepts: user name string
 *	    password string
 *	    authenticating user name string
 *	    argument count
 *	    argument vector
 * Returns: T if password validated, NIL otherwise
 */

long server_login (char *user,char *pwd,char *authuser,int argc,char *argv[])
{
  struct passwd *pw = NIL;
  int level = LOG_NOTICE;
  char *err = "failed";
				/* cretins still haven't given up */
  if ((strlen (user) >= NETMAXUSER) ||
      (authuser && (strlen (authuser) >= NETMAXUSER))) {
    level = LOG_ALERT;		/* escalate this alert */
    err = "SYSTEM BREAK-IN ATTEMPT";
    logtry = 0;			/* render this session useless */
  }
  else if (logtry-- <= 0) err = "excessive login failures";
  else if (disablePlaintext) err = "disabled";
  else if (!(authuser && *authuser)) pw = valpwd (user,pwd,argc,argv);
  else if (valpwd (authuser,pwd,argc,argv)) pw = pwuser (user);
  if (pw && pw_login (pw,authuser,pw->pw_name,NIL,argc,argv)) return T;
  syslog (level|LOG_AUTH,"Login %s user=%.64s auth=%.64s host=%.80s",err,
	  user,(authuser && *authuser) ? authuser : user,tcp_clienthost ());
  sleep (3);			/* slow down possible cracker */
  return NIL;
}

/* Authenticated server log in
 * Accepts: user name string
 *	    authenticating user name string
 *	    argument count
 *	    argument vector
 * Returns: T if password validated, NIL otherwise
 */

long authserver_login (char *user,char *authuser,int argc,char *argv[])
{
  return pw_login (pwuser (user),authuser,user,NIL,argc,argv);
}


/* Log in as anonymous daemon
 * Accepts: argument count
 *	    argument vector
 * Returns: T if successful, NIL if error
 */

long anonymous_login (int argc,char *argv[])
{
				/* log in Mr. A. N. Onymous */
  return pw_login (getpwnam (ANONYMOUSUSER),NIL,NIL,
		   (char *) mail_parameters (NIL,GET_ANONYMOUSHOME,NIL),
		   argc,argv);
}

/* Finish log in and environment initialization
 * Accepts: passwd struct for loginpw()
 *	    optional authentication user name
 *	    user name (NIL for anonymous)
 *	    home directory (NIL to use directory from passwd struct)
 *	    argument count
 *	    argument vector
 * Returns: T if successful, NIL if error
 */

long pw_login (struct passwd *pw,char *auser,char *user,char *home,int argc,
	       char *argv[])
{
  struct group *gr;
  char **t;
  long ret = NIL;
  if (pw && pw->pw_uid) {	/* must have passwd struct for non-UID 0 */
				/* make safe copies of user and home */
    if (user) user = cpystr (pw->pw_name);
    home = cpystr (home ? home : pw->pw_dir);
				/* authorization ID .NE. authentication ID? */
    if (user && auser && *auser && compare_cstring (auser,user)) {
				/* scan list of mail administrators */
      if ((gr = getgrnam (ADMINGROUP)) && (t = gr->gr_mem)) while (*t && !ret)
	if (!compare_cstring (auser,*t++))
	  ret = pw_login (pw,NIL,user,home,argc,argv);
      syslog (LOG_NOTICE|LOG_AUTH,"%s %.80s override of user=%.80s host=%.80s",
	      ret ? "Admin" : "Failed",auser,user,tcp_clienthost ());
    }
				/* normal login */
    else if (((pw->pw_uid == geteuid ()) || loginpw (pw,argc,argv)) &&
	     (ret = env_init (user,home))) chdir (myhomedir ());
    fs_give ((void **) &home);	/* clean up */
    if (user) fs_give ((void **) &user);
  }
  return ret;			/* return status */
}

/* Initialize environment
 * Accepts: user name (NIL for anonymous)
 *	    home directory name
 * Returns: T, always
 */

long env_init (char *user,char *home)
{
  extern MAILSTREAM CREATEPROTO;
  extern MAILSTREAM EMPTYPROTO;
  struct passwd *pw;
  struct stat sbuf;
  char tmp[MAILTMPLEN];
  if (myUserName) fatal ("env_init called twice!");
				/* set up user name */
  myUserName = cpystr (user ? user : ANONYMOUSUSER);
  if (user) {			/* remember user name and home directory */
    nslist[0] = &nshome;	/* home namespace */
    nslist[1] = &nsamigaother;
    nslist[2] = advertisetheworld ? &nsworld : &nsshared;
  }
  else {			/* anonymous user */
    nslist[0] = nslist[1] = NIL,nslist[2] = &nsftp;
    sprintf (tmp,"%s/INBOX",
	     home = (char *) mail_parameters (NIL,GET_ANONYMOUSHOME,NIL));
    sysInbox = cpystr (tmp);	/* make system INBOX */
    anonymous = T;		/* flag as anonymous */
  }
  myHomeDir = cpystr (home);	/* set home directory */
  if (!noautomaticsharedns) {
				/* #ftp namespace */
    if (!ftpHome && (pw = getpwnam ("ftp"))) ftpHome = cpystr (pw->pw_dir);
				/* #public namespace */
    if (!publicHome && (pw = getpwnam ("imappublic")))
      publicHome = cpystr (pw->pw_dir);
				/* #shared namespace */
    if (!anonymous && !sharedHome && (pw = getpwnam ("imapshared")))
      sharedHome = cpystr (pw->pw_dir);
  }
  if (!myLocalHost) mylocalhost ();
  if (!myNewsrc) myNewsrc = cpystr(strcat (strcpy (tmp,myHomeDir),"/.newsrc"));
  if (!newsActive) newsActive = cpystr (ACTIVEFILE);
  if (!newsSpool) newsSpool = cpystr (NEWSSPOOL);
				/* force default prototype to be set */
  if (!createProto) createProto = &CREATEPROTO;
  if (!appendProto) appendProto = &EMPTYPROTO;
				/* re-do open action to get flags */
  (*createProto->dtb->open) (NIL);
  endpwent ();			/* close pw database */
  return T;
}
 
/* Return my user name
 * Accepts: pointer to optional flags
 * Returns: my user name
 */

char *myusername_full (unsigned long *flags)
{
  char *ret = UNLOGGEDUSER;
  if (!myUserName) {		/* get user name if don't have it yet */
    struct passwd *pw;
    struct stat sbuf;
    unsigned long euid = geteuid ();
    char *s = (char *) (euid ? getlogin () : NIL);
				/* look up getlogin() user name or EUID */
    if (!((s && *s && (strlen (s) < NETMAXUSER) && (pw = getpwnam (s)) &&
	   (pw->pw_uid == euid)) || (pw = getpwuid (euid))))
      fatal ("Unable to look up user name");
				/* init environment if not root */
    if (euid) env_init (pw->pw_name,((s = getenv ("HOME")) && *s &&
				     (strlen (s) < NETMAXMBX) &&
				     !stat (s,&sbuf) &&
				     ((sbuf.st_mode & S_IFMT) == S_IFDIR)) ?
			s : pw->pw_dir);
    else ret = pw->pw_name;	/* in case UID 0 user is other than root */
  }
  if (myUserName) {		/* logged in? */
    if (flags) *flags = anonymous ? MU_ANONYMOUS : MU_LOGGEDIN;
    ret = myUserName;		/* return user name */
  }
  else if (flags) *flags = MU_NOTLOGGEDIN;
  return ret;
}


/* Return my local host name
 * Returns: my local host name
 */

char *mylocalhost ()
{
  char tmp[MAILTMPLEN];
  struct hostent *host_name;
  if (!myLocalHost) {
    gethostname(tmp,MAILTMPLEN);/* get local host name */
    myLocalHost = cpystr ((host_name = gethostbyname (tmp)) ?
			  host_name->h_name : tmp);
  }
  return myLocalHost;
}

/* Return my home directory name
 * Returns: my home directory name
 */

char *myhomedir ()
{
  if (!myHomeDir) myusername ();/* initialize if first time */
  return myHomeDir ? myHomeDir : "";
}


/* Return my home mailbox name
 * Returns: my home directory name
 */

static char *mymailboxdir ()
{
  char *home = myhomedir ();
  if (!myMailboxDir && home) {	/* initialize if first time */
    if (mailsubdir) {
      char tmp[MAILTMPLEN];
      sprintf (tmp,"%s/%s",home,mailsubdir);
      myMailboxDir = cpystr (tmp);/* use pre-defined subdirectory of home */
    }
    else myMailboxDir = cpystr (home);
  }
  return myMailboxDir ? myMailboxDir : "";
}


/* Return system standard INBOX
 * Accepts: buffer string
 */

char *sysinbox ()
{
  char tmp[MAILTMPLEN];
  if (!sysInbox) {		/* initialize if first time */
    sprintf (tmp,"%s/%s",MAILSPOOL,myusername ());
    sysInbox = cpystr (tmp);	/* system inbox is from mail spool */
  }
  return sysInbox;
}

/* Return mailbox directory name
 * Accepts: destination buffer
 *	    directory prefix
 *	    name in directory
 * Returns: file name or NIL if error
 */

char *mailboxdir (char *dst,char *dir,char *name)
{
  char tmp[MAILTMPLEN];
  if (dir || name) {		/* if either argument provided */
    if (dir) {
      if (strlen (dir) > NETMAXMBX) return NIL;
      strcpy (tmp,dir);		/* write directory prefix */
    }
    else tmp[0] = '\0';		/* otherwise null string */
    if (name) {
      if (strlen (name) > NETMAXMBX) return NIL;
      strcat (tmp,name);	/* write name in directory */
    }
				/* validate name, return its name */
    if (!mailboxfile (dst,tmp)) return NIL;
  }
				/* no arguments, wants mailbox directory */
  else strcpy (dst,mymailboxdir ());
  return dst;			/* return the name */
}

/* Return mailbox file name
 * Accepts: destination buffer
 *	    mailbox name
 * Returns: file name or empty string for driver-selected INBOX or NIL if error
 */

char *mailboxfile (char *dst,char *name)
{
  struct passwd *pw;
  char *s;
  if (!name || !*name || (*name == '{') || (strlen (name) > NETMAXMBX) ||
      ((anonymous || restrictBox || (*name == '#')) &&
       (strstr (name,"..") || strstr (name,"//") || strstr (name,"/~"))))
    dst = NIL;			/* invalid name */
  else switch (*name) {		/* determine mailbox type based upon name */
  case '#':			/* namespace name */
				/* #ftp/ namespace */
    if (((name[1] == 'f') || (name[1] == 'F')) &&
	((name[2] == 't') || (name[2] == 'T')) &&
	((name[3] == 'p') || (name[3] == 'P')) &&
	(name[4] == '/') && ftpHome) sprintf (dst,"%s/%s",ftpHome,name+5);
				/* #public/ and #shared/ namespaces */
    else if ((((name[1] == 'p') || (name[1] == 'P')) &&
	      ((name[2] == 'u') || (name[2] == 'U')) &&
	      ((name[3] == 'b') || (name[3] == 'B')) &&
	      ((name[4] == 'l') || (name[4] == 'L')) &&
	      ((name[5] == 'i') || (name[5] == 'I')) &&
	      ((name[6] == 'c') || (name[6] == 'C')) &&
	      (name[7] == '/') && (s = publicHome)) ||
	     (!anonymous && ((name[1] == 's') || (name[1] == 'S')) &&
	      ((name[2] == 'h') || (name[2] == 'H')) &&
	      ((name[3] == 'a') || (name[3] == 'A')) &&
	      ((name[4] == 'r') || (name[4] == 'R')) &&
	      ((name[5] == 'e') || (name[5] == 'E')) &&
	      ((name[6] == 'd') || (name[6] == 'D')) &&
	      (name[7] == '/') && (s = sharedHome)))
      sprintf (dst,"%s/%s",s,compare_cstring (name,"INBOX") ? name : "INBOX");
    else dst = NIL;		/* unknown namespace */
    break;

  case '/':			/* root access */
    if (anonymous) dst = NIL;	/* anonymous forbidden to do this */
    else if ((restrictBox & RESTRICTROOT) && strcmp (name,sysinbox ()))
      dst = NIL;		/* restricted and not access to sysinbox */
    else strcpy (dst,name);	/* unrestricted, copy root name */
    break;
  case '~':			/* other user access */
				/* bad syntax or anonymous can't win */
    if (!*++name || anonymous) dst = NIL;
				/* ~/ equivalent to ordinary name */
    else if (*name == '/') sprintf (dst,"%s/%s",mymailboxdir (),name+1);
				/* other user forbidden if restricted */
    else if (restrictBox & RESTRICTOTHERUSER) dst = NIL;
    else {			/* clear box other user */
				/* copy user name */
      for (s = dst; *name && (*name != '/'); *s++ = *name++);
      *s++ = '\0';		/* tie off user name, look up in passwd file */
      if ((pw = getpwnam (dst)) && pw->pw_dir) {
	if (*name) name++;	/* skip past the slash */
				/* canonicalize case of INBOX */
	if (!compare_cstring (name,"INBOX")) name = "INBOX";
				/* remove trailing / from directory */
	if ((s = strrchr (pw->pw_dir,'/')) && !s[1]) *s = '\0';
				/* don't allow ~root/ if restricted root */
	if ((restrictBox & RESTRICTROOT) && !*pw->pw_dir) dst = NIL;
				/* build final name w/ subdir if needed */
	else if (mailsubdir) sprintf (dst,"%s/%s/%s",pw->pw_dir,mailsubdir,name);
	else sprintf (dst,"%s/%s",pw->pw_dir,name);
      }
      else dst = NIL;		/* no such user */
    }
    break;
  case 'I': case 'i':		/* possible INBOX */
    if (!compare_cstring (name+1,"NBOX")) {
				/* if anonymous, use INBOX in mailbox dir */
      if (anonymous) sprintf (dst,"%s/INBOX",mymailboxdir ());
      else *dst = '\0';		/* otherwise driver selects the name */
      break;
    }
				/* drop into to ordinary name case */
  default:			/* ordinary name is easy */
    sprintf (dst,"%s/%s",mymailboxdir (),name);
    break;