/*++

Copyright (c) 1991  Microsoft Corporation

Module Name:

    rusrpass.c

Abstract:

    This module implements routines to get and encrypt the user's name and
    password for transmission to a remote host.

Author:

    Mike Massa (mikemas)           Sept 20, 1991

Revision History:

    Who         When        What
    --------    --------    ----------------------------------------------
    mikemas     9-20-91     created
    MuraliK    10-19-94     Nls Enabled the code

Notes:

    Exports:
    None

--*/

#ident "@(#)ruserpass.c 5.3 3/8/91"
/*
 *  Copyright (c)   1987    Spider Systems Limited
 */

/*  ruserpass.c 1.0     */


/*
 *   /usr/projects/tcp/SCCS.rel3/rel/src/lib/net/0/s.ruserpass.c
 *  @(#)ruserpass.c 5.3
 *
 *  Last delta created  14:11:15 3/4/91
 *  This file extracted 11:20:26 3/8/91
 *
 */
/***************************************************************************/

# include "local.h"
# include "sockutil.h"
# include "nls.h"

//
// Global data
//

//
// BUGBUG: use of this variable is not multithreaded safe!!!!!!
//
char myname[256];

//
// BUGBUG: use of this variable is not multithreaded safe!!!!!
//

static  FILE *cfile;


//
// Local function prototypes
//

static void
rnetrc(
    char  *host,
    char **aname,
    char **apass
    );

static int
token(
    void
    );

#if 0      // prototypes for functions we don't use - mikemas

char *
renvlook(
    char *host
    );

static void
enblkclr(       /* ignores top bit of chars in string str */
    char *blk,
    char *str
    );

static void
renv(
     char  *host,
     char **aname,
     char **apass
    );

static void
enblkclr(
    char *blk,
    char *str
    );

static
void
enblknot(
    char *blk,
    char *crp
    );

static
void
nbssetkey(
    char *key
    );

static
void
blkencrypt(
    char *block,
    int   edflag
    );

static
char *
deblkclr(
    char *blk
    );

void
mkpwclear(
    char *sencpasswd,
    char  mch,
    char *spasswd
    );

#endif


//
// Functions
//

void
ruserpass(
    char  *host,
    char **aname,
    char **apass
    )
{
    char  prompt[128];

//
//  We don't support some things needed to do this lookup. No real need to
//  do it anyway.
//
//  renv(host, aname, apass);

//
// BUGBUG: turned off for Beta. We haven't decided how to support the
//         netrc file yet (ie where does it live?).
//
    if (*aname == NULL || *apass == NULL)
        rnetrc(host, aname, apass);

    if (*aname == NULL) {
        if (getlogin(myname, 256) != 0) {
            exit(1);
        }
        //  sprintf( prompt, "Name (%s:%s): ", host, myname);
        //
        //   Nls Enabled ( MuraliK) 10-19-94
        //
        NlsSPrintf( IDS_USER_NAME_PROMPT, prompt, 128, host, myname);
        *aname = getusername(prompt);
        if ((*aname)[0] == '\0') {
            *aname = myname;
        }
    }

    if ((*aname != NULL) && (*apass == NULL)) {
        // sprintf(prompt, "Password (%s:%s): ", host, myname);
        //
        //   Nls Enabled ( MuraliK) 10-19-94
        //
        NlsSPrintf( IDS_USER_PASSWORD_PROMPT, prompt, 128, host, myname);
        *apass = getpass(prompt);
        if ((*apass)[0] == '\0') {
            exit(1);
        }
    }
}


#define DEFAULT 1
#define LOGIN   2
#define PASSWD  3
#define NOTIFY  4
#define WRITE   5
#define YES 6
#define NO  7
#define COMMAND 8
#define FORCE   9
#define ID  10
#define MACHINE 11

#include <crt\errno.h>

static char tokval[100];

static struct toktab {
    char *tokstr;
    int tval;
} toktab[]= {
    "default",  DEFAULT,
    "login",    LOGIN,
    "password", PASSWD,
    "notify",   NOTIFY,
    "write",    WRITE,
    "yes",      YES,
    "y",        YES,
    "no",       NO,
    "n",        NO,
    "command",  COMMAND,
    "force",    FORCE,
    "machine",  MACHINE,
    0,      0
};


static void
rnetrc(
    char  *host,
    char **aname,
    char **apass
    )
{
    char *hdir, buf[BUFSIZ];
    int t;
    struct _stat stb;

//
//BUGBUG - what is the "HOME" directory in Win32/Posix???
//         replace with ETC for now.
//

    cfile = SockOpenNetworkDataBase("netrc", buf, BUFSIZ, "r");
    if (cfile == NULL) {
        if (errno != ENOENT) {
            perror(buf);
        }
        return;
    }
next:
    while (t = token()) {
        switch(t) {

        case DEFAULT:
            (void) token();
            continue;

        case MACHINE:
            if (token() != ID || strcmp(host, tokval))
                continue;
            while (t = token()) {
                if (t == MACHINE) {
                    break;
                }
                switch(t) {

                case LOGIN:
                    if (token()) {
                        if (*aname == NULL) {
                            if ((*aname = malloc(strlen(tokval) + 1)) == NULL) {
                                //
                                //fprintf(stderr, "Out of memory\n");
                                //
                                //  Nls Enabled (MuraliK) 10-19-94
                                NlsPerror( IDS_OUT_OF_MEMORY, GetLastError());
                                exit(1);
                            }
                            strcpy(*aname, tokval);
                        }
                        else {
                            if (strcmp(*aname, tokval)) {
                                goto next;
                            }
                        }
                    }
                    break;

                case PASSWD:

//
// BUGBUG: Do we want to support this security check in any way????
//
//                  if ( (fstat(fileno(cfile), &stb) >= 0) &&
//                       ((stb.st_mode & 077) != 0) ) {
//                      fprintf(stderr,
//                              "Error - .netrc file not correct mode.\n");
//                      fprintf(stderr,
//                              "Remove password or correct mode.\n");
//                      exit(1);
//                  }

                    if (token() && *apass == NULL) {
                        if ((*apass = malloc(strlen(tokval) + 1)) == NULL) {
                            //
                            //fprintf(stderr, "Out of memory\n");
                            //
                            //  Nls Enabled (MuraliK) 10-19-94
                            NlsPerror( IDS_OUT_OF_MEMORY, GetLastError());
                            exit(1);
                        }
                        strcpy(*apass, tokval);
                    }
                    break;

                case COMMAND:
                case NOTIFY:
                case WRITE:
                case FORCE:
                    (void) token();
                    break;

                default:
                    //fprintf(stderr, "Unknown netrc option %s\n", tokval);
                    //
                    //  Nls Enabled ( MuraliK) 10-19-94
                    //
                    NlsPutMsg( STDERR, IDS_UNKNOWN_NETRC_OPTION, tokval);
                    goto done;
                }
            }
        }
    }
done:
    fclose(cfile);
}


static int
token(
    void
    )
{
    char *cp;
    int c;
    struct toktab *t;

    if (feof(cfile))
        return (0);
    while ((c = getc(cfile)) != EOF &&
        (c == '\n' || c == '\t' || c == ' ' || c == ','))
        continue;
    if (c == EOF)
        return (0);
    cp = tokval;
    if (c == '"') {
        while ((c = getc(cfile)) != EOF && c != '"') {
            if (c == '\\')
                c = getc(cfile);
            *cp++ = (char) c;
        }
    } else {
        *cp++ = (char) c;
        while ((c = getc(cfile)) != EOF
            && c != '\n' && c != '\t' && c != ' ' && c != ',') {
            if (c == '\\')
                c = getc(cfile);
            *cp++ = (char) c;
        }
    }
    *cp = 0;
    if (tokval[0] == 0)
        return (0);
    for (t = toktab; t->tokstr; t++)
        if (!strcmp(t->tokstr, tokval))
            return (t->tval);
    return (ID);
}



#if 0     // we don't need this password encryption stuff - mikemas

static void
renv(
     char  *host,
     char **aname,
     char **apass
    )
{
    register char *cp;
    char *comma;

    cp = renvlook(host);
    if (cp == NULL)
        return;
    if (!isalpha(cp[0]))
        return;
    comma = strchr(cp, ',');
    if (comma == NULL)
        return;
    if (*aname == NULL) {
        if ((*aname = malloc(comma - cp + 1)) == NULL) {
            //
            //fprintf(stderr, "Out of memory\n");
            //
            //  Nls Enabled (MuraliK) 10-19-94
            NlsPerror( IDS_OUT_OF_MEMORY, GetLastError());
            exit(1);
        }
        strncpy(*aname, cp, comma - cp);
    } else
        if (strncmp(*aname, cp, comma - cp))
            return;
    comma++;
    if ((cp = malloc(strlen(comma)+1)) == NULL) {
        //
        //fprintf(stderr, "Out of memory\n");
        //
        //  Nls Enabled (MuraliK) 10-19-94
        NlsPerror( IDS_OUT_OF_MEMORY, GetLastError());
        exit(1);
    }
    strcpy(cp, comma);
    if ((*apass = malloc(16)) == NULL) {
        //
        //fprintf(stderr, "Out of memory\n");
        //
        //  Nls Enabled (MuraliK) 10-19-94
        NlsPerror(  IDS_OUT_OF_MEMORY, GetLastError());
        exit(1);
    }
    mkpwclear(cp, host[0], *apass);
}

static
char *
renvlook(
    char *host
    )
{
    register char *cp, **env;
    extern char **environ;

    env = environ;
    for (env = environ; *env != NULL; env++)
        if (!strncmp(*env, "MACH", 4)) {
            cp = strchr(*env, '=');
            if (cp == NULL)
                continue;
            if (strncmp(*env+4, host, cp-(*env+4)))
                continue;
            return (cp+1);
        }
    return (NULL);
}


/* rest is nbs.c stolen from berknet */

char *
deblkclr(
    char *blk
    );

char *deblknot();
char *nbs8decrypt(), *nbs8encrypt();
static char E[48];

/*
 * The E bit-selection table.
 */
static char e[] = {
    32, 1, 2, 3, 4, 5,
     4, 5, 6, 7, 8, 9,
     8, 9,10,11,12,13,
    12,13,14,15,16,17,
    16,17,18,19,20,21,
    20,21,22,23,24,25,
    24,25,26,27,28,29,
    28,29,30,31,32, 1,
};
static
char *
nbsencrypt(
    char *str,
    char *key,
    char *result
    )
{
    static char buf[20],oldbuf[20];
    register int j;
    result[0] = 0;
    strcpy(oldbuf,key);
    while(*str){
        for(j=0;j<10;j++)buf[j] = 0;
        for(j=0;j<8 && *str;j++)buf[j] = *str++;
        strcat(result,nbs8encrypt(buf,oldbuf));
        strcat(result,"$");
        strcpy(oldbuf,buf);
        }
    return(result);
}
static
char *
nbsdecrypt(
    char *cpt,
    char *key,
    char *result
    )
{
    char *s;
    char c,oldbuf[20];
    result[0] = 0;
    strcpy(oldbuf,key);
    while(*cpt){
        for(s = cpt;*s && *s != '$';s++);
        c = *s;
        *s = 0;
        strcpy(oldbuf,nbs8decrypt(cpt,oldbuf));
        strcat(result,oldbuf);
        if(c == 0)break;
        cpt = s + 1;
        }
    return(result);
}

static
char *
nbs8encrypt(
    char *str,
    char *key
    )
{
    static char keyblk[100], blk[100];
    register int i;

    enblkclr(keyblk,key);
    nbssetkey(keyblk);

    for(i=0;i<48;i++) E[i] = e[i];
    enblkclr(blk,str);
    blkencrypt(blk,0);          /* forward dir */

    return(deblknot(blk));
}

static
char *nbs8decrypt(crp,key)
char *crp, *key; {
    static char keyblk[100], blk[100];
    register int i;

    enblkclr(keyblk,key);
    nbssetkey(keyblk);

    for(i=0;i<48;i++) E[i] = e[i];
    enblknot(blk,crp);
    blkencrypt(blk,1);          /* backward dir */

    return(deblkclr(blk));
}

static void
enblkclr(       /* ignores top bit of chars in string str */
    char *blk,
    char *str
    )
{
    register int i,j;
    char c;
    for(i=0;i<70;i++)blk[i] = 0;
    for(i=0; (c= *str) && i<64; str++){
        for(j=0; j<7; j++, i++)
            blk[i] = (char) ( (c>>(6-j)) & 01 );
        i++;
        }
}

static
char *
deblkclr(
    char *blk
    )
{
    register int i,j;
    char c;
    static char iobuf[30];
    for(i=0; i<10; i++){
        c = 0;
        for(j=0; j<7; j++){
            c <<= 1;
            c |= blk[8*i+j];
            }
        iobuf[i] = c;
    }
    iobuf[i] = 0;
    return(iobuf);
}

static
void
enblknot(blk,crp)
char *blk;
char *crp; {
    register int i,j;
    char c;
    for(i=0;i<70;i++)blk[i] = 0;
    for(i=0; (c= *crp) && i<64; crp++){
        if(c>'Z') c -= 6;
        if(c>'9') c -= 7;
        c -= '.';
        for(j=0; j<6; j++, i++)
            blk[i] = (char) ( (c>>(5-j)) & 01 );
        }
    }

static
char *deblknot(blk)
char *blk; {
    register int i,j;
    char c;
    static char iobuf[30];
    for(i=0; i<11; i++){
        c = 0;
        for(j=0; j<6; j++){
            c <<= 1;
            c |= blk[6*i+j];
            }
        c += '.';
        if(c > '9')c += 7;
        if(c > 'Z')c += 6;
        iobuf[i] = c;
    }
    iobuf[i] = 0;
    return(iobuf);
}

/*
 * This program implements the
 * Proposed Federal Information Processing
 *  Data Encryption Standard.
 * See Federal Register, March 17, 1975 (40FR12134)
 */

/*
 * Initial permutation,
 */
static  char    IP[] = {
    58,50,42,34,26,18,10, 2,
    60,52,44,36,28,20,12, 4,
    62,54,46,38,30,22,14, 6,
    64,56,48,40,32,24,16, 8,
    57,49,41,33,25,17, 9, 1,
    59,51,43,35,27,19,11, 3,
    61,53,45,37,29,21,13, 5,
    63,55,47,39,31,23,15, 7,
};

/*
 * Final permutation, FP = IP^(-1)
 */
static  char    FP[] = {
    40, 8,48,16,56,24,64,32,
    39, 7,47,15,55,23,63,31,
    38, 6,46,14,54,22,62,30,
    37, 5,45,13,53,21,61,29,
    36, 4,44,12,52,20,60,28,
    35, 3,43,11,51,19,59,27,
    34, 2,42,10,50,18,58,26,
    33, 1,41, 9,49,17,57,25,
};

/*
 * Permuted-choice 1 from the key bits
 * to yield C and D.
 * Note that bits 8,16... are left out:
 * They are intended for a parity check.
 */
static  char    PC1_C[] = {
    57,49,41,33,25,17, 9,
     1,58,50,42,34,26,18,
    10, 2,59,51,43,35,27,
    19,11, 3,60,52,44,36,
};

static  char    PC1_D[] = {
    63,55,47,39,31,23,15,
     7,62,54,46,38,30,22,
    14, 6,61,53,45,37,29,
    21,13, 5,28,20,12, 4,
};

/*
 * Sequence of shifts used for the key schedule.
*/
static  char    shifts[] = {
    1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,
};

/*
 * Permuted-choice 2, to pick out the bits from
 * the CD array that generate the key schedule.
 */
static  char    PC2_C[] = {
    14,17,11,24, 1, 5,
     3,28,15, 6,21,10,
    23,19,12, 4,26, 8,
    16, 7,27,20,13, 2,
};

static  char    PC2_D[] = {
    41,52,31,37,47,55,
    30,40,51,45,33,48,
    44,49,39,56,34,53,
    46,42,50,36,29,32,
};

/*
 * The C and D arrays used to calculate the key schedule.
 */

static  char    C[28];
static  char    D[28];
/*
 * The key schedule.
 * Generated from the key.
 */
static  char    KS[16][48];

/*
 * Set up the key schedule from the key.
 */

static
void
nbssetkey(
    char *key
    )
{
    register i, j, k;
    int t;

    /*
     * First, generate C and D by permuting
     * the key.  The low order bit of each
     * 8-bit char is not used, so C and D are only 28
     * bits apiece.
     */
    for (i=0; i<28; i++) {
        C[i] = key[PC1_C[i]-1];
        D[i] = key[PC1_D[i]-1];
    }
    /*
     * To generate Ki, rotate C and D according
     * to schedule and pick up a permutation
     * using PC2.
     */
    for (i=0; i<16; i++) {
        /*
         * rotate.
         */
        for (k=0; k<shifts[i]; k++) {
            t = C[0];
            for (j=0; j<28-1; j++)
                C[j] = C[j+1];
            C[27] = (char) t;
            t = D[0];
            for (j=0; j<28-1; j++)
                D[j] = D[j+1];
            D[27] = (char) t;
        }
        /*
         * get Ki. Note C and D are concatenated.
         */
        for (j=0; j<24; j++) {
            KS[i][j] = C[PC2_C[j]-1];
            KS[i][j+24] = D[PC2_D[j]-28-1];
        }
    }
}


/*
 * The 8 selection functions.
 * For some reason, they give a 0-origin
 * index, unlike everything else.
 */
static  char    S[8][64] = {
    14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
     0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
     4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
    15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13,

    15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
     3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
     0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
    13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9,

    10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
    13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
    13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
     1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12,

     7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
    13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
    10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
     3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14,

     2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
    14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
     4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
    11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3,

    12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
    10,15, 4, 2, 7,12, 9, 5, 6, 1,13,14, 0,11, 3, 8,
     9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
     4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13,

     4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
    13, 0,11, 7, 4, 9, 1,10,14, 3, 5,12, 2,15, 8, 6,
     1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
     6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12,

    13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
     1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
     7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
     2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11,
};

/*
 * P is a permutation on the selected combination
 * of the current L and key.
 */
static  char    P[] = {
    16, 7,20,21,
    29,12,28,17,
     1,15,23,26,
     5,18,31,10,
     2, 8,24,14,
    32,27, 3, 9,
    19,13,30, 6,
    22,11, 4,25,
};

/*
 * The current block, divided into 2 halves.
 */
static  char    L[32], R[32];
static  char    tempL[32];
static  char    f[32];

/*
 * The combination of the key and the input, before selection.
 */
static  char    preS[48];

/*
 * The payoff: encrypt a block.
 */

static
void
blkencrypt(
    char *block,
    int   edflag
    )
{
    int i, ii;
    register t, j, k;

    /*
     * First, permute the bits in the input
     */
    for (j=0; j<64; j++)
        L[j] = block[IP[j]-1];
    /*
     * Perform an encryption operation 16 times.
     */
    for (ii=0; ii<16; ii++) {
        /*
         * Set direction
         */
        if (edflag)
            i = 15-ii;
        else
            i = ii;
        /*
         * Save the R array,
         * which will be the new L.
         */
        for (j=0; j<32; j++)
            tempL[j] = R[j];
        /*
         * Expand R to 48 bits using the E selector;
         * exclusive-or with the current key bits.
         */
        for (j=0; j<48; j++)
            preS[j] = R[E[j]-1] ^ KS[i][j];
        /*
         * The pre-select bits are now considered
         * in 8 groups of 6 bits each.
         * The 8 selection functions map these
         * 6-bit quantities into 4-bit quantities
         * and the results permuted
         * to make an f(R, K).
         * The indexing into the selection functions
         * is peculiar; it could be simplified by
         * rewriting the tables.
         */
        for (j=0; j<8; j++) {
            t = 6*j;
            k = S[j][(preS[t+0]<<5)+
                (preS[t+1]<<3)+
                (preS[t+2]<<2)+
                (preS[t+3]<<1)+
                (preS[t+4]<<0)+
                (preS[t+5]<<4)];
            t = 4*j;
            f[t+0] = (char) ( (k>>3)&01 );
            f[t+1] = (char) ( (k>>2)&01 );
            f[t+2] = (char) ( (k>>1)&01 );
            f[t+3] = (char) ( (k>>0)&01 );
        }
        /*
         * The new R is L ^ f(R, K).
         * The f here has to be permuted first, though.
         */
        for (j=0; j<32; j++)
            R[j] = L[j] ^ f[P[j]-1];
        /*
         * Finally, the new L (the original R)
         * is copied back.
         */
        for (j=0; j<32; j++)
            L[j] = tempL[j];
    }
    /*
     * The output L and R are reversed.
     */
    for (j=0; j<32; j++) {
        t = L[j];
        L[j] = R[j];
        R[j] = (char) t;
    }
    /*
     * The final output
     * gets the inverse permutation of the very original.
     */
    for (j=0; j<64; j++)
        block[j] = L[FP[j]-1];
}

#ifdef _POSIX_SOURCE
#    define UTMP_SIZE     (_POSIX_PATH_MAX + 6)
#else
#    define UTMP_SIZE     (_MAX_PATH + 6)
#endif

/*
    getutmp()
    return a pointer to the system utmp structure associated with
    terminal sttyname, e.g. "/dev/tty3"
    Is version independent-- will work on v6 systems
    return NULL if error
*/
static
struct utmp *
getutmp(
    char *sttyname
    )
{
    static struct utmp utmpstr;
    FILE *fdutmp;
    char *temp;
    char  UTMP[UTMP_SIZE];

    if(sttyname == NULL || sttyname[0] == 0)return(NULL);

    fdutmp = SockOpenNetworkDataBase("utmp", UTMP, UTMP_SIZE, "r");

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

    while(fread(&utmpstr,1,sizeof utmpstr,fdutmp) == sizeof utmpstr)
        if(strcmp(utmpstr.ut_line,sttyname+5) == 0){
            fclose(fdutmp);
            return(&utmpstr);
        }
    fclose(fdutmp);
    return(NULL);
}

static
void
sreverse(
    char *sto,
    char *sfrom
    )
{
    register int i;

    i = strlen(sfrom);
    while (i >= 0)
        *sto++ = sfrom[i--];
}

static
char *
mkenvkey(
    char mch
    )
{
    static char skey[40];
    register struct utmp *putmp;
    char stemp[40], stemp1[40], sttyname[30];
    register char *sk,*p;

    if (_isatty(2))
        strcpy(sttyname,ttyname(2));
    else if (_isatty(0))
        strcpy(sttyname,ttyname(0));
    else if (_isatty(1))
        strcpy(sttyname,ttyname(1));
    else
        return (NULL);
    putmp = getutmp(sttyname);
    if (putmp == NULL)
        return (NULL);
    sk = skey;
    p = putmp->ut_line;
    while (*p)
        *sk++ = *p++;
    *sk++ = mch;
    sprintf(stemp, "%ld", putmp->ut_time);
    sreverse(stemp1, stemp);
    p = stemp1;
    while (*p)
        *sk++ = *p++;
    *sk = 0;
    return (skey);
}


void
mkpwunclear(
    char *spasswd,
    char  mch,
    char *sencpasswd
    )
{
    register char *skey;

    if (spasswd[0] == 0) {
        sencpasswd[0] = 0;
        return;
    }
    skey = mkenvkey(mch);
    if (skey == NULL) {
        // fprintf(stderr, "Can't make key\n");
        //
        //  NLS Enabled  ( 10-19-94)
        //
        NlsPerror( IDS_CANT_MAKE_KEY, GetLastError());
        exit(1);
    }
    nbsencrypt(spasswd, skey, sencpasswd);
}

void
mkpwclear(
    char *sencpasswd,
    char  mch,
    char *spasswd
    )
{
    register char *skey;

    if (sencpasswd[0] == 0) {
        spasswd[0] = 0;
        return;
    }
    skey = mkenvkey(mch);
    if (skey == NULL) {
        // fprintf(stderr, "Can't make key\n");
        //
        //  NLS Enabled  ( 10-19-94)
        //
        NlsPerror( IDS_CANT_MAKE_KEY, GetLastError());
        exit(1);
    }
    nbsdecrypt(sencpasswd, skey, spasswd);
}

#endif