/* saslutil.c
 * Rob Siemborski
 * Tim Martin
 */
/* 
 * Copyright (c) 1998-2016 Carnegie Mellon University.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The name "Carnegie Mellon University" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For permission or any other legal
 *    details, please contact  
 *      Carnegie Mellon University
 *      Center for Technology Transfer and Enterprise Creation
 *      4615 Forbes Avenue
 *      Suite 302
 *      Pittsburgh, PA  15213
 *      (412) 268-7393, fax: (412) 268-7395
 *      innovation@andrew.cmu.edu
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Computing Services
 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
 *
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <config.h>
#include <stdio.h>

#if defined(WIN32)
#define _CRT_RAND_S
#endif

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#include "saslint.h"
#include <saslutil.h>

/*  Contains:
 *
 * sasl_decode64 
 * sasl_encode64
 * sasl_mkchal
 * sasl_utf8verify
 * sasl_randcreate
 * sasl_randfree
 * sasl_randseed
 * sasl_rand
 * sasl_churn
 * sasl_erasebuffer
 */

char *encode_table;
char *decode_table;

#define RPOOL_SIZE 3
struct sasl_rand_s {
    unsigned short pool[RPOOL_SIZE];
    /* since the init time might be really bad let's make this lazy */
    int initialized; 
};

#define CHAR64(c)  (((c) < 0 || (c) > 127) ? -1 : index_64[(c)])

static char basis_64[] =
   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????";

static char index_64[128] = {
    -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
    -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
    -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
    52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1,
    -1, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
    15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
    -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
    41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
};

/* base64 encode
 *  in      -- input data
 *  inlen   -- input data length
 *  out     -- output buffer (will be NUL terminated)
 *  outmax  -- max size of output buffer
 * result:
 *  outlen  -- gets actual length of output buffer (optional)
 * 
 * Returns SASL_OK on success, SASL_BUFOVER if result won't fit
 */

int sasl_encode64(const char *_in,
		  unsigned inlen,
		  char *_out,
		  unsigned outmax,
		  unsigned *outlen)
{
    const unsigned char *in = (const unsigned char *)_in;
    unsigned char *out = (unsigned char *)_out;
    unsigned char oval;
    unsigned olen;

    /* check params */
    if ((inlen > 0) && (in == NULL)) return SASL_BADPARAM;
    
    /* Will it fit? */
    olen = (inlen + 2) / 3 * 4;
    if (outlen) {
	*outlen = olen;
    }
    if (outmax <= olen) {
	return SASL_BUFOVER;
    }

    /* Do the work... */
    while (inlen >= 3) {
      /* user provided max buffer size; make sure we don't go over it */
        *out++ = basis_64[in[0] >> 2];
        *out++ = basis_64[((in[0] << 4) & 0x30) | (in[1] >> 4)];
        *out++ = basis_64[((in[1] << 2) & 0x3c) | (in[2] >> 6)];
        *out++ = basis_64[in[2] & 0x3f];
        in += 3;
        inlen -= 3;
    }
    if (inlen > 0) {
      /* user provided max buffer size; make sure we don't go over it */
        *out++ = basis_64[in[0] >> 2];
        oval = (in[0] << 4) & 0x30;
        if (inlen > 1) oval |= in[1] >> 4;
        *out++ = basis_64[oval];
        *out++ = (inlen < 2) ? '=' : basis_64[(in[1] << 2) & 0x3c];
        *out++ = '=';
    }

    *out = '\0';
    
    return SASL_OK;
}

/* base64 decode
 *  in     -- input data
 *  inlen  -- length of input data
 *  out    -- output data (may be same as in, must have enough space)
 *  outmax  -- max size of output buffer
 * result:
 *  outlen -- actual output length
 *
 * returns:
 * SASL_BADPROT on bad base64,
 * SASL_BUFOVER if result won't fit,
 * SASL_CONTINUE on a partial block,
 * SASL_OK on success
 */

int sasl_decode64(const char *in,
                  unsigned inlen,
                  char *out,
                  unsigned outmax,  /* size of the buffer, not counting the NUL */
                  unsigned *outlen)
{
    unsigned len = 0;
    unsigned j;
    int c[4];
    int saw_equal = 0;

    /* check parameters */
    if (out == NULL) return SASL_FAIL;

    if (inlen > 0 && *in == '\r') return SASL_FAIL;

    while (inlen > 3) {
        /* No data is valid after an '=' character */
        if (saw_equal) {
            return SASL_BADPROT;
        }

	for (j = 0; j < 4; j++) {
	    c[j] = in[0];
	    in++;
	    inlen--;
	}

        if (CHAR64(c[0]) == -1 || CHAR64(c[1]) == -1) return SASL_BADPROT;
        if (c[2] != '=' && CHAR64(c[2]) == -1) return SASL_BADPROT;
        if (c[3] != '=' && CHAR64(c[3]) == -1) return SASL_BADPROT;
        /* No data is valid after a '=' character, unless it is another '=' */
        if (c[2] == '=' && c[3] != '=') return SASL_BADPROT;
        if (c[2] == '=' || c[3] == '=') {
            saw_equal = 1;
        }

        *out++ = (CHAR64(c[0]) << 2) | (CHAR64(c[1]) >> 4);
        if (++len >= outmax) return SASL_BUFOVER;
        if (c[2] != '=') {
            *out++ = ((CHAR64(c[1]) << 4) & 0xf0) | (CHAR64(c[2]) >> 2);
            if (++len >= outmax) return SASL_BUFOVER;
            if (c[3] != '=') {
                *out++ = ((CHAR64(c[2]) << 6) & 0xc0) | CHAR64(c[3]);
                if (++len >= outmax) return SASL_BUFOVER;
            }
        }
    }

    *out = '\0'; /* NUL terminate the output string */

    if (outlen) *outlen = len;

    if (inlen != 0) {
        if (saw_equal) {
            /* Unless there is CRLF at the end? */
            return SASL_BADPROT;
        } else {
	    return (SASL_CONTINUE);
        }
    }

    return SASL_OK;
}

/* make a challenge string (NUL terminated)
 *  buf      -- buffer for result
 *  maxlen   -- max length of result
 *  hostflag -- 0 = don't include hostname, 1 = include hostname
 * returns final length or 0 if not enough space
 */

int sasl_mkchal(sasl_conn_t *conn,
		char *buf,
		unsigned maxlen,
		unsigned hostflag)
{
  sasl_rand_t *pool = NULL;
  unsigned long randnum;
  int ret;
  time_t now;
  unsigned len;

  len = 4			/* <.>\0 */
    + (2 * 20);			/* 2 numbers, 20 => max size of 64bit
				 * ulong in base 10 */
  if (hostflag && conn->serverFQDN)
    len += (unsigned) strlen(conn->serverFQDN) + 1 /* for the @ */;

  if (maxlen < len)
    return 0;

  ret = sasl_randcreate(&pool);
  if(ret != SASL_OK) return 0; /* xxx sasl return code? */

  sasl_rand(pool, (char *)&randnum, sizeof(randnum));
  sasl_randfree(&pool);

  time(&now);

  if (hostflag && conn->serverFQDN)
    snprintf(buf,maxlen, "<%lu.%lu@%s>", randnum, now, conn->serverFQDN);
  else
    snprintf(buf,maxlen, "<%lu.%lu>", randnum, now);

  return (int) strlen(buf);
}

  /* borrowed from larry. probably works :)
   * probably is also in acap server somewhere
   */
int sasl_utf8verify(const char *str, unsigned len)
{
  unsigned i;
  for (i = 0; i < len; i++) {
    /* how many octets? */
    int seqlen = 0;
    while (str[i] & (0x80 >> seqlen)) ++seqlen;
    if (seqlen == 0) continue; /* this is a valid US-ASCII char */
    if (seqlen == 1) return SASL_BADPROT; /* this shouldn't happen here */
    if (seqlen > 6) return SASL_BADPROT; /* illegal */
    while (--seqlen)
      if ((str[++i] & 0xC0) != 0xF0) return SASL_BADPROT; /* needed a 10 octet */
  }
  return SASL_OK;
}      

/* 
 * To see why this is really bad see RFC 1750
 *
 * unfortunatly there currently is no way to make 
 * cryptographically secure pseudo random numbers
 * without specialized hardware etc...
 * thus, this is for nonce use only
 */
void getranddata(unsigned short ret[RPOOL_SIZE])
{
    long curtime;
    
    memset(ret, 0, RPOOL_SIZE*sizeof(unsigned short));

#ifdef DEV_RANDOM    
    {
	int fd;

	fd = open(DEV_RANDOM, O_RDONLY);
	if(fd != -1) {
	    unsigned char *buf = (unsigned char *)ret;
	    ssize_t bytesread = 0;
	    size_t bytesleft = RPOOL_SIZE*sizeof(unsigned short);
	    
	    do {
		bytesread = read(fd, buf, bytesleft);
		if(bytesread == -1 && errno == EINTR) continue;
		else if(bytesread <= 0) break;
		bytesleft -= bytesread;
		buf += bytesread;
	    } while(bytesleft != 0);
		
	    close(fd);
	}
    }
#endif

#ifdef HAVE_GETPID
    ret[0] ^= (unsigned short) getpid();
#endif

#ifdef HAVE_GETTIMEOFDAY
    {
	struct timeval tv;
	
	/* xxx autoconf macro */
#ifdef _SVID_GETTOD
	if (!gettimeofday(&tv))
#else
	if (!gettimeofday(&tv, NULL))
#endif
	{
	    /* longs are guaranteed to be at least 32 bits; we need
	       16 bits in each short */
	    ret[0] ^= (unsigned short) (tv.tv_sec & 0xFFFF);
	    ret[1] ^= (unsigned short) (clock() & 0xFFFF);
	    ret[1] ^= (unsigned short) (tv.tv_usec >> 16);
	    ret[2] ^= (unsigned short) (tv.tv_usec & 0xFFFF);
	    return;
	}
    }
#endif /* HAVE_GETTIMEOFDAY */
    
    /* if all else fails just use time() */
    curtime = (long) time(NULL); /* better be at least 32 bits */
    
    ret[0] ^= (unsigned short) (curtime >> 16);
    ret[1] ^= (unsigned short) (curtime & 0xFFFF);
    ret[2] ^= (unsigned short) (clock() & 0xFFFF);
    
    return;
}

int sasl_randcreate(sasl_rand_t **rpool)
{
  (*rpool)=sasl_ALLOC(sizeof(sasl_rand_t));
  if ((*rpool) == NULL) return SASL_NOMEM;

  /* init is lazy */
  (*rpool)->initialized = 0;

  return SASL_OK;
}

void sasl_randfree(sasl_rand_t **rpool)
{
    sasl_FREE(*rpool);
}

void sasl_randseed (sasl_rand_t *rpool, const char *seed, unsigned len)
{
    /* is it acceptable to just use the 1st 3 char's given??? */
    unsigned int lup;

    /* check params */
    if (seed == NULL) return;
    if (rpool == NULL) return;

    rpool->initialized = 1;

    if (len > sizeof(unsigned short)*RPOOL_SIZE)
      len = sizeof(unsigned short)*RPOOL_SIZE;

    for (lup = 0; lup < len; lup += 2)
	rpool->pool[lup/2] = (seed[lup] << 8) + seed[lup + 1];
}

static void randinit(sasl_rand_t *rpool)
{
    if (!rpool) return;
    
    if (!rpool->initialized) {
	getranddata(rpool->pool);
	rpool->initialized = 1;
#if !(defined(WIN32)||defined(macintosh))
#ifndef HAVE_JRAND48
    {
      /* xxx varies by platform */
	unsigned int *foo = (unsigned int *)rpool->pool;
	srandom(*foo);
    }
#endif /* HAVE_JRAND48 */
#elif defined(WIN32)
    {
	unsigned int *foo = (unsigned int *)rpool->pool;
	srand(*foo);
    }
#endif /* WIN32 */
    }

}

void sasl_rand (sasl_rand_t *rpool, char *buf, unsigned len)
{
    unsigned int lup;
#if defined(WIN32) && !defined(__MINGW32__)
    unsigned int randomValue;
#endif

    /* check params */
    if (!rpool || !buf) return;
    
    /* init if necessary */
    randinit(rpool);

    for (lup = 0; lup < len; lup++) {
#if defined(__MINGW32__)
	buf[lup] = (char) (rand() >> 8);
#elif defined(WIN32)
	if (rand_s(&randomValue) != 0) {
	    randomValue = rand();
	}

	buf[lup] = (char) (randomValue >> 8);
#elif defined(macintosh)
	buf[lup] = (char) (rand() >> 8);
#else /* !WIN32 && !macintosh */
#ifdef HAVE_JRAND48
	buf[lup] = (char) (jrand48(rpool->pool) >> 8);
#else
	buf[lup] = (char) (random() >> 8);
#endif /* HAVE_JRAND48 */
#endif /* WIN32 */
    }
}

/* this function is just a bad idea all around, since we're not trying to
   implement a true random number generator */
void sasl_churn (sasl_rand_t *rpool, const char *data, unsigned len)
{
    unsigned int lup;
    
    /* check params */
    if (!rpool || !data) return;
    
    /* init if necessary */
    randinit(rpool);
    
    for (lup=0; lup<len; lup++)
	rpool->pool[lup % RPOOL_SIZE] ^= data[lup];
}

void sasl_erasebuffer(char *buf, unsigned len) {
    memset(buf, 0, len);
}

/* Lowercase string in place */
char *sasl_strlower (
  char *val
)
{
    int i;

    if (val == NULL) {
	return (NULL);
    }

/* don't use tolower(), as it is locale dependent */

    for (i = 0; val[i] != '\0'; i++) {
	if (val[i] >= 'A' && val[i] <= 'Z') {
	    val[i] = val[i] - 'A' + 'a';
	}
    }

    return (val);
}

/* A version of gethostname that tries hard to return a FQDN */
int get_fqhostname(
  char *name,  
  int namelen,
  int abort_if_no_fqdn
)
{
    int return_value;
    struct addrinfo hints;
    struct addrinfo *result;

    return_value = gethostname (name, namelen);
    if (return_value != 0) {
	return (return_value);
    }

    if (strchr (name, '.') != NULL) {
	goto LOWERCASE;
    }

/* gethostname hasn't returned a FQDN, we have to canonify it ourselves */
    hints.ai_family = PF_UNSPEC;
    hints.ai_flags = AI_CANONNAME;
    hints.ai_socktype = SOCK_STREAM;	/* TCP only */
/* A value of zero for ai_protocol indicates the caller will accept any protocol. or IPPROTO_TCP? */
    hints.ai_protocol = 0;  /* 0 or IPPROTO_xxx for IPv4 and IPv6 */
    hints.ai_addrlen = 0;
    hints.ai_canonname = NULL;
    hints.ai_addr = NULL;
    hints.ai_next = NULL;

    if (getaddrinfo(name,
		  NULL,		/* don't care abour service/port */
		  &hints,
		  &result) != 0) {
        if (abort_if_no_fqdn) {
	    /* errno on Unix, WSASetLastError on Windows are already done by the function */
	    return (-1);
	} else {
	    goto LOWERCASE;
	}
    }

    if (result == NULL || result->ai_canonname == NULL) {
	freeaddrinfo (result);
        if (abort_if_no_fqdn) {
#ifdef WIN32
	    WSASetLastError (WSANO_DATA);
#elif defined(ENODATA)
	    errno = ENODATA;
#elif defined(EADDRNOTAVAIL)
	    errno = EADDRNOTAVAIL;
#endif
	    return (-1);
	} else {
	    goto LOWERCASE;
	}
    }

    if (strchr (result->ai_canonname, '.') == NULL) {
	freeaddrinfo (result);
        if (abort_if_no_fqdn) {
#ifdef WIN32
	    WSASetLastError (WSANO_DATA);
#elif defined(ENODATA)
	    errno = ENODATA;
#elif defined(EADDRNOTAVAIL)
	    errno = EADDRNOTAVAIL;
#endif
	    return (-1);
	} else {
	    goto LOWERCASE;
	}
    }


/* Do we need to check for buffer overflow and set errno? */
    strncpy (name, result->ai_canonname, namelen);
    freeaddrinfo (result);

LOWERCASE:
    sasl_strlower (name);
    return (0);
}

#if defined(WIN32) && !defined(__MINGW64_VERSION_MAJOR)
/***************************************************************************** 
 * 
 *  MODULE NAME : GETOPT.C 
 * 
 *  COPYRIGHTS: 
 *             This module contains code made available by IBM 
 *             Corporation on an AS IS basis.  Any one receiving the 
 *             module is considered to be licensed under IBM copyrights 
 *             to use the IBM-provided source code in any way he or she 
 *             deems fit, including copying it, compiling it, modifying 
 *             it, and redistributing it, with or without 
 *             modifications.  No license under any IBM patents or 
 *             patent applications is to be implied from this copyright 
 *             license. 
 * 
 *             A user of the module should understand that IBM cannot 
 *             provide technical support for the module and will not be 
 *             responsible for any consequences of use of the program. 
 * 
 *             Any notices, including this one, are not to be removed 
 *             from the module without the prior written consent of 
 *             IBM. 
 * 
 *  AUTHOR:   Original author: 
 *                 G. R. Blair (BOBBLAIR at AUSVM1) 
 *                 Internet: bobblair@bobblair.austin.ibm.com 
 * 
 *            Extensively revised by: 
 *                 John Q. Walker II, Ph.D. (JOHHQ at RALVM6) 
 *                 Internet: johnq@ralvm6.vnet.ibm.com 
 * 
 *****************************************************************************/ 
 
/****************************************************************************** 
 * getopt() 
 * 
 * The getopt() function is a command line parser.  It returns the next 
 * option character in argv that matches an option character in opstring. 
 * 
 * The argv argument points to an array of argc+1 elements containing argc 
 * pointers to character strings followed by a null pointer. 
 * 
 * The opstring argument points to a string of option characters; if an 
 * option character is followed by a colon, the option is expected to have 
 * an argument that may or may not be separated from it by white space. 
 * The external variable optarg is set to point to the start of the option 
 * argument on return from getopt(). 
 * 
 * The getopt() function places in optind the argv index of the next argument 
 * to be processed.  The system initializes the external variable optind to 
 * 1 before the first call to getopt(). 
 * 
 * When all options have been processed (that is, up to the first nonoption 
 * argument), getopt() returns EOF.  The special option "--" may be used to 
 * delimit the end of the options; EOF will be returned, and "--" will be 
 * skipped. 
 * 
 * The getopt() function returns a question mark (?) when it encounters an 
 * option character not included in opstring.  This error message can be 
 * disabled by setting opterr to zero.  Otherwise, it returns the option 
 * character that was detected. 
 * 
 * If the special option "--" is detected, or all options have been 
 * processed, EOF is returned. 
 * 
 * Options are marked by either a minus sign (-) or a slash (/). 
 * 
 * No errors are defined. 
 *****************************************************************************/ 
 
#include <string.h>                 /* for strchr() */ 
 
/* static (global) variables that are specified as exported by getopt() */ 
__declspec(dllexport) char *optarg = NULL;    /* pointer to the start of the option argument  */ 
__declspec(dllexport) int   optind = 1;       /* number of the next argv[] to be evaluated    */ 
__declspec(dllexport) int   opterr = 1;       /* non-zero if a question mark should be returned */

 
/* handle possible future character set concerns by putting this in a macro */ 
#define _next_char(string)  (char)(*(string+1)) 
 
int getopt(int argc, char *argv[], char *opstring) 
{ 
    static char *pIndexPosition = NULL; /* place inside current argv string */ 
    char *pArgString = NULL;        /* where to start from next */ 
    char *pOptString;               /* the string in our program */ 
 
 
    if (pIndexPosition != NULL) { 
        /* we last left off inside an argv string */ 
        if (*(++pIndexPosition)) { 
            /* there is more to come in the most recent argv */ 
            pArgString = pIndexPosition; 
        } 
    } 
 
    if (pArgString == NULL) { 
        /* we didn't leave off in the middle of an argv string */ 
        if (optind >= argc) { 
            /* more command-line arguments than the argument count */ 
            pIndexPosition = NULL;  /* not in the middle of anything */ 
            return EOF;             /* used up all command-line arguments */ 
        } 
 
        /*--------------------------------------------------------------------- 
         * If the next argv[] is not an option, there can be no more options. 
         *-------------------------------------------------------------------*/ 
        pArgString = argv[optind++]; /* set this to the next argument ptr */ 
 
        if (('/' != *pArgString) && /* doesn't start with a slash or a dash? */ 
            ('-' != *pArgString)) { 
            --optind;               /* point to current arg once we're done */ 
            optarg = NULL;          /* no argument follows the option */ 
            pIndexPosition = NULL;  /* not in the middle of anything */ 
            return EOF;             /* used up all the command-line flags */ 
        } 
 
        /* check for special end-of-flags markers */ 
        if ((strcmp(pArgString, "-") == 0) || 
            (strcmp(pArgString, "--") == 0)) { 
            optarg = NULL;          /* no argument follows the option */ 
            pIndexPosition = NULL;  /* not in the middle of anything */ 
            return EOF;             /* encountered the special flag */ 
        } 
 
        pArgString++;               /* look past the / or - */ 
    } 
 
    if (':' == *pArgString) {       /* is it a colon? */ 
        /*--------------------------------------------------------------------- 
         * Rare case: if opterr is non-zero, return a question mark; 
         * otherwise, just return the colon we're on. 
         *-------------------------------------------------------------------*/ 
        return (opterr ? (int)'?' : (int)':'); 
    } 
    else if ((pOptString = strchr(opstring, *pArgString)) == 0) { 
        /*--------------------------------------------------------------------- 
         * The letter on the command-line wasn't any good. 
         *-------------------------------------------------------------------*/ 
        optarg = NULL;              /* no argument follows the option */ 
        pIndexPosition = NULL;      /* not in the middle of anything */ 
        return (opterr ? (int)'?' : (int)*pArgString); 
    } 
    else { 
        /*--------------------------------------------------------------------- 
         * The letter on the command-line matches one we expect to see 
         *-------------------------------------------------------------------*/ 
        if (':' == _next_char(pOptString)) { /* is the next letter a colon? */ 
            /* It is a colon.  Look for an argument string. */ 
            if ('\0' != _next_char(pArgString)) {  /* argument in this argv? */ 
                optarg = &pArgString[1];   /* Yes, it is */ 
            } 
            else { 
                /*------------------------------------------------------------- 
                 * The argument string must be in the next argv. 
                 * But, what if there is none (bad input from the user)? 
                 * In that case, return the letter, and optarg as NULL. 
                 *-----------------------------------------------------------*/ 
                if (optind < argc) 
                    optarg = argv[optind++]; 
                else { 
                    optarg = NULL; 
                    return (opterr ? (int)'?' : (int)*pArgString); 
                } 
            } 
            pIndexPosition = NULL;  /* not in the middle of anything */ 
        } 
        else { 
            /* it's not a colon, so just return the letter */ 
            optarg = NULL;          /* no argument follows the option */ 
            pIndexPosition = pArgString;    /* point to the letter we're on */ 
        } 
        return (int)*pArgString;    /* return the letter that matched */ 
    } 
} 

#ifndef PASSWORD_MAX
#  define PASSWORD_MAX 255
#endif

#include <conio.h>
char *
getpass(prompt)
const char *prompt;
{
	register char *p;
	register int c;
	static char pbuf[PASSWORD_MAX];

	fprintf(stderr, "%s", prompt); (void) fflush(stderr);
	for (p=pbuf; (c = _getch())!=13 && c!=EOF;) {
		if (p < &pbuf[sizeof(pbuf)-1])
			*p++ = (char) c;
	}
	*p = '\0';
	fprintf(stderr, "\n"); (void) fflush(stderr);
	return(pbuf);
}



#endif /* WIN32 */
