iceauth/dist/process.c

/*
 *
Copyright 1989, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

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
OPEN GROUP 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.

Except as contained in this notice, the name of The Open Group shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from The Open Group.
 * *
 * Original Author of "xauth" : Jim Fulton, MIT X Consortium
 * Modified into "iceauth"    : Ralph Mor, X Consortium
 */

#include "iceauth.h"
#include <ctype.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>

#define SECURERPC "SUN-DES-1"
#define K5AUTH "KERBEROS-V5-1"

#define ICEAUTH_DEFAULT_RETRIES 10	/* number of competitors we expect */
#define ICEAUTH_DEFAULT_TIMEOUT 2	/* in seconds, be quick */
#define ICEAUTH_DEFAULT_DEADTIME 600L	/* 10 minutes in seconds */

typedef struct _AuthList {		/* linked list of entries */
    struct _AuthList *next;
    IceAuthFileEntry *auth;
} AuthList;

#define add_to_list(h,t,e) {if (t) (t)->next = (e); else (h) = (e); (t) = (e);}

typedef int (*ProcessFunc)(const char *, int, int, const char **);
typedef int (*DoFunc)(const char *, int, IceAuthFileEntry *, void *);

typedef struct _CommandTable {		/* commands that are understood */
    const char *name;			/* full name */
    unsigned int minlen;		/* unique prefix */
    unsigned int maxlen;		/* strlen(name) */
    ProcessFunc processfunc;		/* handler */
    const char *helptext;		/* what to print for help */
} CommandTable;

struct _extract_data {			/* for iterating */
    FILE *fp;				/* input source */
    const char *filename;		/* name of input */
    Bool used_stdout;			/* whether or not need to close */
    int nwritten;			/* number of entries written */
    const char *cmd;			/* for error messages */
};

struct _list_data {			/* for iterating */
    FILE *fp;				/* output file */
};


/*
 * private data
 */
static const char *stdin_filename = "(stdin)";  /* for messages */
static const char *stdout_filename = "(stdout)";  /* for messages */
static const char *Yes = "yes";		/* for messages */
static const char *No = "no";			/* for messages */

static int binaryEqual ( const char *a, const char *b, unsigned len );
static void prefix ( const char *fn, int n );
static void badcommandline ( const char *cmd );
static char *skip_space ( char *s );
static char *skip_nonspace ( char *s );
static char **split_into_words ( char *src, int *argcp );
static FILE *open_file ( const char **filenamep, const char *mode, Bool *usedstdp, const char *srcfn, int srcln, const char *cmd );
static int read_auth_entries ( FILE *fp, AuthList **headp, AuthList **tailp );
static int cvthexkey ( const char *hexstr, char **ptrp );
static int dispatch_command ( const char *inputfilename, int lineno, int argc, const char **argv, const CommandTable *tab, int *statusp );
static void die ( int sig ) _X_NORETURN;
static void catchsig ( int sig ) _X_NORETURN;
static void register_signals ( void );
static int write_auth_file ( char *tmp_nam, size_t tmp_nam_len );
static void fprintfhex ( FILE *fp, unsigned int len, const char *cp );
static int dump_entry ( const char *inputfilename, int lineno, IceAuthFileEntry *auth, void *data );
static int extract_entry ( const char *inputfilename, int lineno, IceAuthFileEntry *auth, void *data );
static int match_auth ( IceAuthFileEntry *a, IceAuthFileEntry *b, int *authDataSame );
static int merge_entries ( AuthList **firstp, AuthList *second, int *nnewp, int *nreplp, int *ndupp );
static int search_and_do ( const char *inputfilename, int lineno, int start, int argc, const char *argv[], DoFunc do_func, void *data );
static int remove_entry ( const char *inputfilename, int lineno, IceAuthFileEntry *auth, void *data );
static int do_help ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_questionmark ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_list ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_merge ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_extract ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_add ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_remove ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_info ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_exit ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_quit ( const char *inputfilename, int lineno, int argc, const char **argv );
static int do_source ( const char *inputfilename, int lineno, int argc, const char **argv );

static const CommandTable command_table[] = {	/* table of known commands */
{ "add", 2, 3, do_add,
"\
add       add an entry\n\
          add protoname protodata netid authname authdata"
},

{ "exit", 3, 4, do_exit,
"\
exit      save changes and exit program"
},

{ "extract", 3, 7, do_extract,
"\
extract   extract entries into file\n\
          extract filename <protoname=$> <protodata=$> <netid=$> <authname=$>"
},

{ "help", 1, 4, do_help,
"\
help      print help\n\
          help <topic>"
},

{ "info", 1, 4, do_info,
"\
info      print information about entries"
},

{ "list", 1, 4, do_list,
"\
list      list entries\n\
          list <protoname=$> <protodata=$> <netid=$> <authname=$>"
},

{ "merge", 1, 5, do_merge,
"\
merge     merge entries from files\n\
          merge filename1 <filename2> <filename3> ..."
},

{ "quit", 1, 4, do_quit,
"\
quit      abort changes and exit program" },

{ "remove", 1, 6, do_remove,
"\
remove    remove entries\n\
          remove <protoname=$> <protodata=$> <netid=$> <authname=$>"
},

{ "source", 1, 6, do_source,
"\
source    read commands from file\n\
          source filename"
},

{ "?", 1, 1, do_questionmark,
"\
?         list available commands" },

{ NULL, 0, 0, NULL, NULL },
};

#define COMMAND_NAMES_PADDED_WIDTH 10	/* wider than anything above */


static Bool okay_to_use_stdin = True;	/* set to false after using */

static const char * const hex_table[] = {	/* for printing hex digits */
    "00", "01", "02", "03", "04", "05", "06", "07",
    "08", "09", "0a", "0b", "0c", "0d", "0e", "0f",
    "10", "11", "12", "13", "14", "15", "16", "17",
    "18", "19", "1a", "1b", "1c", "1d", "1e", "1f",
    "20", "21", "22", "23", "24", "25", "26", "27",
    "28", "29", "2a", "2b", "2c", "2d", "2e", "2f",
    "30", "31", "32", "33", "34", "35", "36", "37",
    "38", "39", "3a", "3b", "3c", "3d", "3e", "3f",
    "40", "41", "42", "43", "44", "45", "46", "47",
    "48", "49", "4a", "4b", "4c", "4d", "4e", "4f",
    "50", "51", "52", "53", "54", "55", "56", "57",
    "58", "59", "5a", "5b", "5c", "5d", "5e", "5f",
    "60", "61", "62", "63", "64", "65", "66", "67",
    "68", "69", "6a", "6b", "6c", "6d", "6e", "6f",
    "70", "71", "72", "73", "74", "75", "76", "77",
    "78", "79", "7a", "7b", "7c", "7d", "7e", "7f",
    "80", "81", "82", "83", "84", "85", "86", "87",
    "88", "89", "8a", "8b", "8c", "8d", "8e", "8f",
    "90", "91", "92", "93", "94", "95", "96", "97",
    "98", "99", "9a", "9b", "9c", "9d", "9e", "9f",
    "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
    "a8", "a9", "aa", "ab", "ac", "ad", "ae", "af",
    "b0", "b1", "b2", "b3", "b4", "b5", "b6", "b7",
    "b8", "b9", "ba", "bb", "bc", "bd", "be", "bf",
    "c0", "c1", "c2", "c3", "c4", "c5", "c6", "c7",
    "c8", "c9", "ca", "cb", "cc", "cd", "ce", "cf",
    "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7",
    "d8", "d9", "da", "db", "dc", "dd", "de", "df",
    "e0", "e1", "e2", "e3", "e4", "e5", "e6", "e7",
    "e8", "e9", "ea", "eb", "ec", "ed", "ee", "ef",
    "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
    "f8", "f9", "fa", "fb", "fc", "fd", "fe", "ff",
};

static unsigned int hexvalues[256];	/* for parsing hex input */

static mode_t original_umask = 0;	/* for restoring */


/*
 * private utility procedures
 */

#define copystring(s)	( s != NULL ? strdup(s) : NULL )

static int
binaryEqual (
    register const char	*a,
    register const char	*b,
    register unsigned	len)

{
    while (len--)
	if (*a++ != *b++)
	    return 0;
    return 1;
}

static void prefix (const char *fn, int n)
{
    fprintf (stderr, "%s: %s:%d:  ", ProgramName, fn, n);
}

static void badcommandline (const char *cmd)
{
    fprintf (stderr, "bad \"%s\" command line\n", cmd);
}

static char *skip_space (register char *s)
{
    if (!s) return NULL;

    for ( ; *s && isascii(*s) && isspace(*s); s++)
	;
    return s;
}


static char *skip_nonspace (register char *s)
{
    if (!s) return NULL;

    /* put quoting into loop if need be */
    for ( ; *s && isascii(*s) && !isspace(*s); s++)
	;
    return s;
}

#ifndef HAVE_REALLOCARRAY
static inline void *
reallocarray(void *optr, size_t nmemb, size_t size)
{
    if ((nmemb > 0) && (SIZE_MAX / nmemb < size)) {
        errno = ENOMEM;
        return NULL;
    }
    return realloc(optr, size * nmemb);
}
#endif

static char **split_into_words (  /* argvify string */
    char *src,
    int *argcp)
{
    char *jword;
    char **argv;
    int cur, total;

    *argcp = 0;
#define WORDSTOALLOC 6			/* most lines are short */
    argv = (char **) malloc (WORDSTOALLOC * sizeof (char *));
    if (!argv) return NULL;
    cur = 0;
    total = WORDSTOALLOC;

    /*
     * split the line up into separate, nul-terminated tokens; the last
     * "token" will point to the empty string so that it can be bashed into
     * a null pointer.
     */

    do {
	char savec;

	jword = skip_space (src);
	src = skip_nonspace (jword);
	savec = *src;
	*src = '\0';
	if (cur == total) {
	    char **prevargv = argv;
	    total += WORDSTOALLOC;
	    argv = reallocarray (argv, total, sizeof (char *));
	    if (!argv) {
		free (prevargv);
		return NULL;
	    }
	}
	argv[cur++] = jword;
	if (savec) src++;		/* if not last on line advance */
    } while (jword != src);

    argv[--cur] = NULL;			/* smash empty token to end list */
    *argcp = cur;
    return argv;
}


static FILE *open_file (
    const char **filenamep,
    const char *mode,
    Bool *usedstdp,
    const char *srcfn,
    int srcln,
    const char *cmd)
{
    FILE *fp;

    if (strcmp (*filenamep, "-") == 0) {
	*usedstdp = True;
					/* select std descriptor to use */
	if (mode[0] == 'r') {
	    if (okay_to_use_stdin) {
		okay_to_use_stdin = False;
		*filenamep = stdin_filename;
		return stdin;
	    } else {
		prefix (srcfn, srcln);
		fprintf (stderr, "%s:  stdin already in use\n", cmd);
		return NULL;
	    }
	} else {
	    *filenamep = stdout_filename;
	    return stdout;		/* always okay to use stdout */
	}
    }

    fp = fopen (*filenamep, mode);
    if (!fp) {
	prefix (srcfn, srcln);
	fprintf (stderr, "%s:  unable to open file %s\n", cmd, *filenamep);
    }
    return fp;
}


static int read_auth_entries (FILE *fp, AuthList **headp, AuthList **tailp)
{
    IceAuthFileEntry *auth;
    AuthList *head, *tail;
    int n;

    head = tail = NULL;
    n = 0;
					/* put all records into linked list */
    while ((auth = IceReadAuthFileEntry (fp)) != NULL) {
	AuthList *l = (AuthList *) malloc (sizeof (AuthList));
	if (!l) {
	    fprintf (stderr,
		     "%s:  unable to alloc entry reading auth file\n",
		     ProgramName);
	    exit (1);
	}
	l->next = NULL;
	l->auth = auth;
	if (tail) 			/* if not first time through append */
	  tail->next = l;
	else
	  head = l;			/* first time through, so assign */
	tail = l;
	n++;
    }
    *headp = head;
    *tailp = tail;
    return n;
}


static int cvthexkey (	/* turn hex key string into octets */
    const char *hexstr,
    char **ptrp)
{
    unsigned int i;
    unsigned int len = 0;
    char *retval;
    unsigned char *us;
    char savec = '\0';

    /* count */
    for (const char *s = hexstr; *s; s++) {
	if (!isascii(*s)) return -1;
	if (isspace(*s)) continue;
	if (!isxdigit(*s)) return -1;
	len++;
    }

    /* if 0 or odd, then there was an error */
    if (len == 0 || (len & 1) == 1) return -1;


    /* now we know that the input is good */
    len >>= 1;
    retval = malloc (len);
    if (!retval) {
	fprintf (stderr, "%s:  unable to allocate %d bytes for hexkey\n",
		 ProgramName, len);
	return -1;
    }

    for (us = (unsigned char *) retval, i = len; i > 0; hexstr++) {
	char c = *hexstr;

	if (isspace(c)) continue;	 /* already know it is ascii */
	if (isupper(c))
	    c = tolower(c);
	if (savec) {
#define atoh(c) ((c) - (((c) >= '0' && (c) <= '9') ? '0' : ('a'-10)))
	    *us = (unsigned char)((atoh(savec) << 4) + atoh(c));
#undef atoh
	    savec = 0;		/* ready for next character */
	    us++;
	    i--;
	} else {
	    savec = c;
	}
    }
    *ptrp = retval;
    return (int) len;
}

static int dispatch_command (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv,
    const CommandTable *tab,
    int *statusp)
{
    const char *cmd;
    size_t n;
					/* scan table for command */
    cmd = argv[0];
    n = strlen (cmd);
    for (const CommandTable *ct = tab; ct->name; ct++) {
					/* look for unique prefix */
	if (n >= ct->minlen && n <= ct->maxlen &&
	    strncmp (cmd, ct->name, n) == 0) {
	    *statusp = (*(ct->processfunc))(inputfilename, lineno, argc, argv);
	    return 1;
	}
    }

    *statusp = 1;
    return 0;
}


static AuthList *iceauth_head = NULL;	/* list of auth entries */
static Bool iceauth_existed = False;	/* if was present at initialize */
static Bool iceauth_modified = False;	/* if added, removed, or merged */
static Bool iceauth_allowed = True;	/* if allowed to write auth file */
static char *iceauth_filename = NULL;
static volatile Bool dying = False;

/* poor man's puts(), for under signal handlers */
#define WRITES(fd, S) (void)write((fd), (S), strlen((S)))

/* ARGSUSED */
static void die (_X_UNUSED int sig)
{
    dying = True;
    _exit (auth_finalize ());
    /* NOTREACHED */
}

static void catchsig (int sig)
{
#ifdef SYSV
    if (sig > 0) signal (sig, die);	/* re-establish signal handler */
#endif
    /*
     * fileno() might not be reentrant, avoid it if possible, and use
     * stderr instead of stdout
     */
#ifdef STDERR_FILENO
    if (verbose && iceauth_modified) WRITES(STDERR_FILENO, "\r\n");
#else
    if (verbose && iceauth_modified) WRITES(fileno(stderr), "\r\n");
#endif
    die (sig);
    /* NOTREACHED */
}

static void register_signals (void)
{
    signal (SIGINT, catchsig);
    signal (SIGTERM, catchsig);
#ifdef SIGHUP
    signal (SIGHUP, catchsig);
#endif
    return;
}


/*
 * public procedures for parsing lines of input
 */

int auth_initialize ( char *authfilename )
{
    int n;
    FILE *authfp;
    Bool exists;

    register_signals ();

    bzero ((char *) hexvalues, sizeof hexvalues);
    hexvalues['0'] = 0;
    hexvalues['1'] = 1;
    hexvalues['2'] = 2;
    hexvalues['3'] = 3;
    hexvalues['4'] = 4;
    hexvalues['5'] = 5;
    hexvalues['6'] = 6;
    hexvalues['7'] = 7;
    hexvalues['8'] = 8;
    hexvalues['9'] = 9;
    hexvalues['a'] = hexvalues['A'] = 0xa;
    hexvalues['b'] = hexvalues['B'] = 0xb;
    hexvalues['c'] = hexvalues['C'] = 0xc;
    hexvalues['d'] = hexvalues['D'] = 0xd;
    hexvalues['e'] = hexvalues['E'] = 0xe;
    hexvalues['f'] = hexvalues['F'] = 0xf;

    if (break_locks && verbose) {
	printf ("Attempting to break locks on authority file %s\n",
		authfilename);
    }

    iceauth_filename = strdup(authfilename);

    if (ignore_locks) {
	if (break_locks) IceUnlockAuthFile (authfilename);
    } else {
	n = IceLockAuthFile (authfilename, ICEAUTH_DEFAULT_RETRIES,
			 ICEAUTH_DEFAULT_TIMEOUT,
			 (break_locks ? 0L : ICEAUTH_DEFAULT_DEADTIME));
	if (n != IceAuthLockSuccess) {
	    const char *reason = "unknown error";
	    switch (n) {
	      case IceAuthLockError:
		reason = "error";
		break;
	      case IceAuthLockTimeout:
		reason = "timeout";
		break;
	    }
	    fprintf (stderr, "%s:  %s in locking authority file %s\n",
		     ProgramName, reason, authfilename);
	    return -1;
	}
    }

    /* these checks can only be done reliably after the file is locked */
    exists = (access (authfilename, F_OK) == 0);
    if (exists && access (authfilename, W_OK) != 0) {
	fprintf (stderr,
	 "%s:  %s not writable, changes will be ignored\n",
		 ProgramName, authfilename);
	iceauth_allowed = False;
    }

    original_umask = umask (0077);	/* disallow non-owner access */

    authfp = fopen (authfilename, "rb");
    if (!authfp) {
	int olderrno = errno;

					/* if file there then error */
	if (access (authfilename, F_OK) == 0) {	 /* then file does exist! */
	    errno = olderrno;
	    return -1;
	}				/* else ignore it */
	fprintf (stderr,
		 "%s:  creating new authority file %s\n",
		 ProgramName, authfilename);
    } else {
	AuthList *head, *tail;

	iceauth_existed = True;
	n = read_auth_entries (authfp, &head, &tail);
	(void) fclose (authfp);
	if (n < 0) {
	    fprintf (stderr,
		     "%s:  unable to read auth entries from file \"%s\"\n",
		     ProgramName, authfilename);
	    return -1;
	}
	iceauth_head = head;
    }

    iceauth_modified = False;

    if (verbose) {
	printf ("%s authority file %s\n",
		ignore_locks ? "Ignoring locks on" : "Using", authfilename);
    }
    return 0;
}

static int write_auth_file (char *tmp_nam, size_t tmp_nam_len)
{
    FILE *fp;

    if ((strlen(iceauth_filename) + 3) > tmp_nam_len) {
	strncpy(tmp_nam, "filename too long", tmp_nam_len);
	tmp_nam[tmp_nam_len - 1] = '\0';
	return -1;
    }

    strcpy (tmp_nam, iceauth_filename);
    strcat (tmp_nam, "-n");		/* for new */
    (void) unlink (tmp_nam);
    fp = fopen (tmp_nam, "wb");		/* umask is still set to 0077 */
    if (!fp) {
	fprintf (stderr, "%s:  unable to open tmp file \"%s\"\n",
		 ProgramName, tmp_nam);
	return -1;
    }

    for (AuthList *list = iceauth_head; list; list = list->next) {
	IceWriteAuthFileEntry (fp, list->auth);
    }

    (void) fclose (fp);
    return 0;
}

int auth_finalize (void)
{
    if (iceauth_modified) {
	if (dying) {
	    if (verbose) {
		/*
		 * called from a signal handler -- printf is *not* reentrant; also
		 * fileno() might not be reentrant, avoid it if possible, and use
		 * stderr instead of stdout
		 */
#ifdef STDERR_FILENO
		WRITES(STDERR_FILENO, "\nAborting changes to authority file ");
		WRITES(STDERR_FILENO, iceauth_filename);
		WRITES(STDERR_FILENO, "\n");
#else
		WRITES(fileno(stderr), "\nAborting changes to authority file ");
		WRITES(fileno(stderr), iceauth_filename);
		WRITES(fileno(stderr), "\n");
#endif
	    }
	} else if (!iceauth_allowed) {
	    fprintf (stderr,
		     "%s:  %s not writable, changes ignored\n",
		     ProgramName, iceauth_filename);
	} else {
	    char temp_name[1024];		/* large filename size */

	    if (verbose) {
		printf ("%s authority file %s\n",
			ignore_locks ? "Ignoring locks and writing" :
			"Writing", iceauth_filename);
	    }
	    temp_name[0] = '\0';
	    if (write_auth_file (temp_name, sizeof(temp_name)) == -1) {
		fprintf (stderr,
			 "%s:  unable to write authority file %s\n",
			 ProgramName, temp_name);
	    } else {
		(void) unlink (iceauth_filename);
#ifdef WIN32
		if (rename(temp_name, iceauth_filename) == -1)
#else
		/* Attempt to rename() if link() fails, since this may be on a FS that does not support hard links */
		if (link (temp_name, iceauth_filename) == -1 && rename(temp_name, iceauth_filename) == -1)
#endif
		{
		    fprintf (stderr,
		     "%s:  unable to link authority file %s, use %s\n",
			     ProgramName, iceauth_filename, temp_name);
		} else {
		    (void) unlink (temp_name);
		}
	    }
	}
    }

    if (!ignore_locks && (iceauth_filename != NULL)) {
	IceUnlockAuthFile (iceauth_filename);
    }
    (void) umask (original_umask);
    return 0;
}

int process_command (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    int status;

    if (argc < 1 || !argv || !argv[0]) return 1;

    if (dispatch_command (inputfilename, lineno, argc, argv,
			  command_table, &status))
      return status;

    prefix (inputfilename, lineno);
    fprintf (stderr, "unknown command \"%s\"\n", argv[0]);
    return 1;
}


/*
 * utility routines
 */

static void fprintfhex (
    register FILE *fp,
    unsigned int len,
    const char *cp)
{
    const unsigned char *ucp = (const unsigned char *) cp;

    for (; len > 0; len--, ucp++) {
	register const char *s = hex_table[*ucp];
	putc (s[0], fp);
	putc (s[1], fp);
    }
    return;
}

/* ARGSUSED */
static int dump_entry (
    const char *inputfilename _X_UNUSED,
    int lineno _X_UNUSED,
    IceAuthFileEntry *auth,
    void *data)
{
    struct _list_data *ld = (struct _list_data *) data;
    FILE *fp = ld->fp;

    fprintf (fp, "%s", auth->protocol_name);
    putc (' ', fp);
    if (auth->protocol_data_length > 0)
	fprintfhex (fp, auth->protocol_data_length, auth->protocol_data);
    else
	fprintf (fp, "\"\"");
    putc (' ', fp);
    fprintf (fp, "%s", auth->network_id);
    putc (' ', fp);
    fprintf (fp, "%s", auth->auth_name);
    putc (' ', fp);

    if (auth->auth_data_length == 0)
	fprintf (fp, "\"\"");
    else if (!strcmp(auth->auth_name, SECURERPC) ||
	!strcmp(auth->auth_name, K5AUTH))
	fwrite (auth->auth_data, sizeof (char), auth->auth_data_length, fp);
    else
	fprintfhex (fp, auth->auth_data_length, auth->auth_data);
    putc ('\n', fp);

    return 0;
}

static int extract_entry (
    const char *inputfilename,
    int lineno,
    IceAuthFileEntry *auth,
    void *data)
{
    struct _extract_data *ed = (struct _extract_data *) data;

    if (!ed->fp) {
	ed->fp = open_file (&ed->filename, "wb",
			    &ed->used_stdout,
			    inputfilename, lineno, ed->cmd);
	if (!ed->fp) {
	    prefix (inputfilename, lineno);
	    fprintf (stderr,
		     "unable to open extraction file \"%s\"\n",
		     ed->filename);
	    return -1;
	}
    }
    IceWriteAuthFileEntry (ed->fp, auth);
    ed->nwritten++;

    return 0;
}


static int match_auth (
    register IceAuthFileEntry *a,
    register IceAuthFileEntry *b,
    int *authDataSame)
{
    int match = strcmp (a->protocol_name, b->protocol_name) == 0 &&
	    strcmp (a->network_id, b->network_id) == 0 &&
            strcmp (a->auth_name, b->auth_name) == 0;

    if (match)
    {
	*authDataSame = (a->auth_data_length == b->auth_data_length &&
	    binaryEqual (a->auth_data, b->auth_data, a->auth_data_length));
    }
    else
	*authDataSame = 0;

    return (match);
}


static int merge_entries (
    AuthList **firstp, AuthList *second,
    int *nnewp, int *nreplp, int *ndupp)
{
    AuthList *first, *tail;
    int n = 0, nnew = 0, nrepl = 0, ndup = 0;

    if (!second) return 0;

    if (!*firstp) {			/* if nothing to merge into */
	*firstp = second;
	for (tail = *firstp, n = 1; tail->next; n++, tail = tail->next) ;
	*nnewp = n;
	*nreplp = 0;
	*ndupp = 0;
	return n;
    }

    first = *firstp;
    /*
     * find end of first list and stick second list on it
     */
    for (tail = first; tail->next; tail = tail->next) ;
    tail->next = second;

    /*
     * run down list freeing duplicate entries; if an entry is okay, then
     * bump the tail up to include it, otherwise, cut the entry out of
     * the chain.
     */
    for (AuthList *b = second; b; ) {
	AuthList *next = b->next;	/* in case we free it */
	AuthList *a = first;
	int duplicate = 0;

	for (;;) {
	    int authDataSame;
	    if (match_auth (a->auth, b->auth, &authDataSame)) {
		if (authDataSame)
		{
		    /* found a complete duplicate, ignore */
		    duplicate = 1;
		    break;
		}
		else
		{
		    /* found a duplicate, but auth data differs */

		    AuthList tmp;		/* swap it in for old one */
		    tmp = *a;
		    *a = *b;
		    *b = tmp;
		    a->next = b->next;
		    IceFreeAuthFileEntry (b->auth);
		    free ((char *) b);
		    b = NULL;
		    tail->next = next;
		    nrepl++;
		    nnew--;
		    break;
		}
	    }
	    if (a == tail) break;	/* if have looked at left side */
	    a = a->next;
	}
	if (!duplicate && b) {		/* if we didn't remove it */
	    tail = b;			/* bump end of first list */
	}
	b = next;

	if (duplicate)
	    ndup++;
	else
	{
	    n++;
	    nnew++;
	}
    }

    *nnewp = nnew;
    *nreplp = nrepl;
    *ndupp = ndup;
    return n;

}


static int search_and_do (
    const char *inputfilename,
    int lineno,
    int start,
    int argc,
    const char *argv[],
    DoFunc do_func,
    void *data)
{
    int status = 0;
    int errors = 0;
    AuthList *next;

    for (AuthList *l = iceauth_head; l; l = next)
    {
	const char *protoname, *protodata, *netid, *authname;

	next = l->next;

	protoname = protodata = netid = authname = NULL;

	for (int i = start; i < argc; i++)
	{
	    if (!strncmp ("protoname=", argv[i], 10))
		protoname = argv[i] + 10;
	    else if (!strncmp ("protodata=", argv[i], 10))
		protodata = argv[i] + 10;
	    else if (!strncmp ("netid=", argv[i], 6))
		netid = argv[i] + 6;
	    else if (!strncmp ("authname=", argv[i], 9))
		authname = argv[i] + 9;
	}

	status = 0;

	if (protoname || protodata || netid || authname)
	{
	    if (protoname && strcmp (protoname, l->auth->protocol_name))
		continue;

	    if (protodata && !binaryEqual (protodata,
		l->auth->protocol_data, l->auth->protocol_data_length))
		continue;

	    if (netid && strcmp (netid, l->auth->network_id))
		continue;

	    if (authname && strcmp (authname, l->auth->auth_name))
		continue;

	    status = (*do_func) (inputfilename, lineno, l->auth, data);

	    if (status < 0)
		break;
	}
    }

    if (status < 0)
	errors -= status;		/* since status is negative */

    return (errors);
}


/* ARGSUSED */
static int remove_entry (
    const char *inputfilename _X_UNUSED,
    int lineno _X_UNUSED,
    IceAuthFileEntry *auth,
    void *data)
{
    int *nremovedp = (int *) data;
    AuthList **listp = &iceauth_head;
    AuthList *list;

    /*
     * unlink the auth we were asked to
     */
    while ((list = *listp)->auth != auth)
	listp = &list->next;
    *listp = list->next;
    IceFreeAuthFileEntry (list->auth);                    /* free the auth */
    free (list);				    /* free the link */
    iceauth_modified = True;
    (*nremovedp)++;
    return 1;
}

/*
 * action routines
 */

/*
 * help
 */
int print_help (
    FILE *fp,
    const char *cmd)
{
    int n = 0;

    fprintf (fp, "\n");
    if (!cmd) {				/* if no cmd, print all help */
	for (const CommandTable *ct = command_table; ct->name; ct++) {
	    fprintf (fp, "%s\n\n", ct->helptext);
	    n++;
	}
    } else {
	size_t len = strlen (cmd);
	for (const CommandTable *ct = command_table; ct->name; ct++) {
	    if (strncmp (cmd, ct->name, len) == 0) {
		fprintf (fp, "%s\n\n", ct->helptext);
		n++;
	    }
	}
    }

    return n;
}

static int do_help (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    const char *cmd = (argc > 1 ? argv[1] : NULL);
    int n;

    n = print_help (stdout, cmd);

    if (n < 0 || (n == 0 && !cmd)) {
	prefix (inputfilename, lineno);
	fprintf (stderr, "internal error with help");
	if (cmd) {
	    fprintf (stderr, " on command \"%s\"", cmd);
	}
	fprintf (stderr, "\n");
	return 1;
    }

    if (n == 0) {
	prefix (inputfilename, lineno);
	/* already know that cmd is set in this case */
	fprintf (stderr, "no help for nonexistent command \"%s\"\n", cmd);
    }

    return 0;
}

/*
 * questionmark
 */
/* ARGSUSED */
static int do_questionmark (
    const char *inputfilename _X_UNUSED,
    int lineno _X_UNUSED,
    int argc _X_UNUSED,
    const char **argv _X_UNUSED)
{
#define WIDEST_COLUMN 72
    unsigned int col = WIDEST_COLUMN;

    printf ("Commands:\n");
    for (const CommandTable *ct = command_table; ct->name; ct++) {
	if ((col + ct->maxlen) > WIDEST_COLUMN) {
	    if (ct != command_table) {
		putc ('\n', stdout);
	    }
	    fputs ("        ", stdout);
	    col = 8;			/* length of string above */
	}
	fputs (ct->name, stdout);
	col += ct->maxlen;
	for (unsigned int i = ct->maxlen; i < COMMAND_NAMES_PADDED_WIDTH; i++) {
	    putc (' ', stdout);
	    col++;
	}
    }
    if (col != 0) {
	putc ('\n', stdout);
    }

    /* allow bad lines since this is help */
    return 0;
}

/*
 * list [displayname ...]
 */
static int do_list (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    struct _list_data ld;

    ld.fp = stdout;

    if (argc == 1) {
	if (iceauth_head) {
	    for (AuthList *l = iceauth_head; l; l = l->next) {
		dump_entry (inputfilename, lineno, l->auth, &ld);
	    }
	}
	return 0;
    }
    else
    {
	return (search_and_do (inputfilename, lineno, 1, argc, argv,
	    dump_entry, &ld));
    }
}

/*
 * merge filename [filename ...]
 */
static int do_merge (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    int errors = 0;
    AuthList *listhead, *listtail;

    if (argc < 2) {
	prefix (inputfilename, lineno);
	badcommandline (argv[0]);
	return 1;
    }

    listhead = listtail = NULL;

    for (int i = 1; i < argc; i++) {
	const char *filename = argv[i];
	FILE *fp;
	Bool used_stdin = False;
	int nentries;
	AuthList *head, *tail;

	fp = open_file (&filename, "rb",
			&used_stdin, inputfilename, lineno,
			argv[0]);
	if (!fp) {
	    errors++;
	    continue;
	}

	head = tail = NULL;
	nentries = read_auth_entries (fp, &head, &tail);
	if (nentries == 0) {
	    prefix (inputfilename, lineno);
	    fprintf (stderr, "unable to read any entries from file \"%s\"\n",
		     filename);
	    errors++;
	} else {			/* link it in */
	    add_to_list (listhead, listtail, head);
 	}

	if (!used_stdin) (void) fclose (fp);
    }

    /*
     * if we have new entries, merge them in (freeing any duplicates)
     */
    if (listhead) {
        int nentries, nnew, nrepl, ndup;

	nentries = merge_entries (&iceauth_head, listhead,
	    &nnew, &nrepl, &ndup);
	if (verbose)
	  printf ("%d entries read in:  %d new, %d replacement%s\n",
	  	  nentries, nnew, nrepl, nrepl != 1 ? "s" : "");
	if (nentries > 0) iceauth_modified = True;
    }

    return 0;
}

/*
 * extract filename displayname [displayname ...]
 */
static int do_extract (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    int errors;
    struct _extract_data ed;

    if (argc < 3) {
	prefix (inputfilename, lineno);
	badcommandline (argv[0]);
	return 1;
    }

    ed.fp = NULL;
    ed.filename = argv[1];
    ed.nwritten = 0;
    ed.cmd = argv[0];

    errors = search_and_do (inputfilename, lineno, 2, argc, argv,
	extract_entry, &ed);

    if (!ed.fp) {
	fprintf (stderr,
		 "No matches found, authority file \"%s\" not written\n",
		 ed.filename);
    } else {
	if (verbose) {
	    printf ("%d entries written to \"%s\"\n",
		    ed.nwritten, ed.filename);
	}
	if (!ed.used_stdout) {
	    (void) fclose (ed.fp);
	}
    }

    return errors;
}


/*
 * add protoname protodata netid authname authdata
 */
static int do_add (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    int n, nnew, nrepl, ndup;
    const char *protoname;
    const char *protodata_hex;
    char *protodata = NULL; /* not required */
    const char *netid;
    const char *authname;
    const char *authdata_hex;
    char *authdata = NULL;
    int protodata_len, authdata_len;
    IceAuthFileEntry *auth = NULL;
    AuthList *list;
    int status = 0;

    if (argc != 6 || !argv[1] || !argv[2] ||
	!argv[3] || !argv[4] || !argv[5])
    {
	prefix (inputfilename, lineno);
	badcommandline (argv[0]);
	return 1;
    }

    protoname = argv[1];
    protodata_hex = argv[2];
    netid = argv[3];
    authname = argv[4];
    authdata_hex = argv[5];

    protodata_len = strlen (protodata_hex);
    if (protodata_len > 0)
    {
	if (protodata_len > 1 &&
	    protodata_hex[0] == '"' && protodata_hex[protodata_len - 1] == '"')
	{
	    protodata = malloc (protodata_len - 1);
	    if (protodata)
	    {
		strncpy (protodata, protodata_hex + 1, protodata_len - 2);
		protodata_len -= 2;
	    }
	    else
		goto add_bad_malloc;
	}
	else
	{
	    protodata_len = cvthexkey (protodata_hex, &protodata);
	    if (protodata_len < 0)
	    {
		prefix (inputfilename, lineno);
		fprintf (stderr,
	       "protodata_hex contains odd number of or non-hex characters\n");
		return (1);
	    }
	}
    }

    authdata_len = strlen (authdata_hex);
    if (authdata_len > 1 &&
	authdata_hex[0] == '"' && authdata_hex[authdata_len - 1] == '"')
    {
	authdata = malloc (authdata_len - 1);
	if (authdata)
	{
	    strncpy (authdata, authdata_hex + 1, authdata_len - 2);
	    authdata_len -= 2;
	}
	else
	    goto add_bad_malloc;
    }
    else if (!strcmp (protoname, SECURERPC) || !strcmp (protoname, K5AUTH))
    {
	authdata = malloc (authdata_len + 1);
	if (authdata)
	    strcpy (authdata, authdata_hex);
	else
	    goto add_bad_malloc;
    }
    else
    {
	authdata_len = cvthexkey (authdata_hex, &authdata);
	if (authdata_len < 0)
	{
	    prefix (inputfilename, lineno);
	    fprintf (stderr,
	       "authdata_hex contains odd number of or non-hex characters\n");
	    free (protodata);
	    return (1);
	}
    }

    auth = (IceAuthFileEntry *) malloc (sizeof (IceAuthFileEntry));

    if (!auth)
	goto add_bad_malloc;

    auth->protocol_name = copystring (protoname);
    auth->protocol_data_length = protodata_len;
    auth->protocol_data = protodata;
    auth->network_id = copystring (netid);
    auth->auth_name = copystring (authname);
    auth->auth_data_length = authdata_len;
    auth->auth_data = authdata;

    if (!auth->protocol_name ||
	(!auth->protocol_data && auth->protocol_data_length > 0) ||
        !auth->network_id || !auth->auth_name ||
	(!auth->auth_data && auth->auth_data_length > 0))
    {
	goto add_bad_malloc;
    }

    list = (AuthList *) malloc (sizeof (AuthList));

    if (!list)
	goto add_bad_malloc;

    list->next = NULL;
    list->auth = auth;

    /*
     * merge it in; note that merge will deal with allocation
     */

    n = merge_entries (&iceauth_head, list, &nnew, &nrepl, &ndup);

    if (n > 0)
	iceauth_modified = True;
    else
    {
	prefix (inputfilename, lineno);
	if (ndup > 0)
	{
	    status = 0;
	    fprintf (stderr, "no records added - all duplicate\n");
	}
	else
	{
	    status = 1;
	    fprintf (stderr, "unable to merge in added record\n");
	}
	goto cant_add;
    }

    return 0;


add_bad_malloc:

    status = 1;
    prefix (inputfilename, lineno);
    fprintf (stderr, "unable to allocate memory to add an entry\n");

cant_add:

    if (protodata)
	free (protodata);
    if (authdata)
	free (authdata);
    if (auth)
    {
	if (auth->protocol_name)
	    free (auth->protocol_name);
	/* auth->protocol_data already freed,
	   since it's the same as protodata */
	if (auth->network_id)
	    free (auth->network_id);
	if (auth->auth_name)
	    free (auth->auth_name);
	/* auth->auth_data already freed,
	   since it's the same as authdata */
	free ((char *) auth);
    }

    return status;
}

/*
 * remove displayname
 */
static int do_remove (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    int nremoved = 0;
    int errors;

    if (argc < 2) {
	prefix (inputfilename, lineno);
	badcommandline (argv[0]);
	return 1;
    }

    errors = search_and_do (inputfilename, lineno, 1, argc, argv,
	remove_entry, &nremoved);
    if (verbose) printf ("%d entries removed\n", nremoved);
    return errors;
}

/*
 * info
 */
static int do_info (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    int n;
    AuthList *l;

    if (argc != 1) {
	prefix (inputfilename, lineno);
	badcommandline (argv[0]);
	return 1;
    }

    for (l = iceauth_head, n = 0; l; l = l->next, n++) ;

    printf ("Authority file:       %s\n",
	    iceauth_filename ? iceauth_filename : "(none)");
    printf ("File new:             %s\n", iceauth_existed ? No : Yes);
    printf ("File locked:          %s\n", ignore_locks ? No : Yes);
    printf ("Number of entries:    %d\n", n);
    printf ("Changes honored:      %s\n", iceauth_allowed ? Yes : No);
    printf ("Changes made:         %s\n", iceauth_modified ? Yes : No);
    printf ("Current input:        %s:%d\n", inputfilename, lineno);
    return 0;
}


/*
 * exit
 */
static Bool alldone = False;

/* ARGSUSED */
static int do_exit (
    const char *inputfilename _X_UNUSED,
    int lineno _X_UNUSED,
    int argc _X_UNUSED,
    const char **argv _X_UNUSED)
{
    /* allow bogus stuff */
    alldone = True;
    return 0;
}

/*
 * quit
 */
/* ARGSUSED */
static int do_quit (
    const char *inputfilename _X_UNUSED,
    int lineno _X_UNUSED,
    int argc _X_UNUSED,
    const char **argv _X_UNUSED)
{
    /* allow bogus stuff */
    die (0);
    /* NOTREACHED */
    return -1;				/* for picky compilers */
}


/*
 * source filename
 */
static int do_source (
    const char *inputfilename,
    int lineno,
    int argc,
    const char **argv)
{
    const char *script;
    FILE *fp;
    Bool used_stdin = False;
    int errors = 0;
    int sublineno = 0;
    Bool prompt = False;		/* only true if reading from tty */

    if (argc != 2 || !argv[1]) {
	prefix (inputfilename, lineno);
	badcommandline (argv[0]);
	return 1;
    }

    script = argv[1];

    fp = open_file (&script, "r", &used_stdin, inputfilename, lineno, argv[0]);
    if (!fp) {
	return 1;
    }

    if (verbose && used_stdin && isatty (fileno (fp))) prompt = True;

    while (!alldone) {
	char buf[BUFSIZ];
	size_t len;
	char **subargv;
	int subargc;

	buf[0] = '\0';
	if (prompt) {
	    printf ("iceauth> ");
	    fflush (stdout);
	}
	if (fgets (buf, sizeof buf, fp) == NULL) break;
	sublineno++;
	len = strlen (buf);
	if (len == 0 || buf[0] == '#') continue;
	if (buf[len-1] != '\n') {
	    prefix (script, sublineno);
	    fprintf (stderr, "line too long\n");
	    errors++;
	    break;
	}
	buf[--len] = '\0';		/* remove new line */
	subargv = split_into_words (buf, &subargc);
	if (subargv) {
	    int status = process_command (script, sublineno, subargc,
                                          (const char **) subargv);
	    free ((char *) subargv);
	    errors += status;
	} else {
	    prefix (script, sublineno);
	    fprintf (stderr, "unable to break line into words\n");
	    errors++;
	}
    }

    if (!used_stdin) {
	(void) fclose (fp);
    }
    return errors;
}