ref: 07a776fad9c93ecc8b0635a9d96107b729ca0469
dir: /sys/src/cmd/auth/authsrv.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ndb.h>
#include <regexp.h>
#include <mp.h>
#include <libsec.h>
#include <authsrv.h>
#include "authcmdlib.h"
int debug;
Ndb *db;
char raddr[128];
/* Microsoft auth constants */
enum {
MShashlen = 16,
MSchallen = 8,
MSresplen = 24,
};
int ticketrequest(Ticketreq*);
void challengebox(Ticketreq*);
void changepasswd(Ticketreq*);
void apop(Ticketreq*, int);
void chap(Ticketreq*);
void mschap(Ticketreq*);
void http(Ticketreq*);
void vnc(Ticketreq*);
int speaksfor(char*, char*);
void replyerror(char*, ...);
void getraddr(char*);
void mkkey(char*);
void randombytes(uchar*, int);
void nthash(uchar hash[MShashlen], char *passwd);
void lmhash(uchar hash[MShashlen], char *passwd);
void ntv2hash(uchar hash[MShashlen], char *passwd, char *user, char *dom);
void mschalresp(uchar resp[MSresplen], uchar hash[MShashlen], uchar chal[MSchallen]);
void desencrypt(uchar data[8], uchar key[7]);
int tickauthreply(Ticketreq*, char*);
void safecpy(char*, char*, int);
void
main(int argc, char *argv[])
{
char buf[TICKREQLEN];
Ticketreq tr;
ARGBEGIN{
case 'd':
debug++;
}ARGEND
strcpy(raddr, "unknown");
if(argc >= 1)
getraddr(argv[argc-1]);
alarm(10*60*1000); /* kill a connection after 10 minutes */
db = ndbopen("/lib/ndb/auth");
if(db == 0)
syslog(0, AUTHLOG, "no /lib/ndb/auth");
srand(time(0)*getpid());
for(;;){
if(readn(0, buf, TICKREQLEN) <= 0)
exits(0);
convM2TR(buf, &tr);
switch(buf[0]){
case AuthTreq:
ticketrequest(&tr);
break;
case AuthChal:
challengebox(&tr);
break;
case AuthPass:
changepasswd(&tr);
break;
case AuthApop:
apop(&tr, AuthApop);
break;
case AuthChap:
chap(&tr);
break;
case AuthMSchap:
mschap(&tr);
break;
case AuthCram:
apop(&tr, AuthCram);
break;
case AuthHttp:
http(&tr);
break;
case AuthVNC:
vnc(&tr);
break;
default:
syslog(0, AUTHLOG, "unknown ticket request type: %d", buf[0]);
exits(0);
}
}
/* not reached */
}
int
ticketrequest(Ticketreq *tr)
{
char akey[DESKEYLEN];
char hkey[DESKEYLEN];
Ticket t;
char tbuf[2*TICKETLEN+1];
if(findkey(KEYDB, tr->authid, akey) == 0){
/* make one up so caller doesn't know it was wrong */
mkkey(akey);
if(debug)
syslog(0, AUTHLOG, "tr-fail authid %s", raddr);
}
if(findkey(KEYDB, tr->hostid, hkey) == 0){
/* make one up so caller doesn't know it was wrong */
mkkey(hkey);
if(debug)
syslog(0, AUTHLOG, "tr-fail hostid %s(%s)", tr->hostid, raddr);
}
memset(&t, 0, sizeof(t));
memmove(t.chal, tr->chal, CHALLEN);
strcpy(t.cuid, tr->uid);
if(speaksfor(tr->hostid, tr->uid))
strcpy(t.suid, tr->uid);
else {
mkkey(akey);
mkkey(hkey);
if(debug)
syslog(0, AUTHLOG, "tr-fail %s@%s(%s) -> %s@%s no speaks for",
tr->uid, tr->hostid, raddr, tr->uid, tr->authid);
}
mkkey(t.key);
tbuf[0] = AuthOK;
t.num = AuthTc;
convT2M(&t, tbuf+1, hkey);
t.num = AuthTs;
convT2M(&t, tbuf+1+TICKETLEN, akey);
if(write(1, tbuf, 2*TICKETLEN+1) < 0){
if(debug)
syslog(0, AUTHLOG, "tr-fail %s@%s(%s): hangup",
tr->uid, tr->hostid, raddr);
exits(0);
}
if(debug)
syslog(0, AUTHLOG, "tr-ok %s@%s(%s) -> %s@%s",
tr->uid, tr->hostid, raddr, tr->uid, tr->authid);
return 0;
}
void
challengebox(Ticketreq *tr)
{
long chal;
char *key, *netkey;
char kbuf[DESKEYLEN], nkbuf[DESKEYLEN], hkey[DESKEYLEN];
char buf[NETCHLEN+1];
char *err;
key = findkey(KEYDB, tr->uid, kbuf);
netkey = findkey(NETKEYDB, tr->uid, nkbuf);
if(key == 0 && netkey == 0){
/* make one up so caller doesn't know it was wrong */
mkkey(nkbuf);
netkey = nkbuf;
if(debug)
syslog(0, AUTHLOG, "cr-fail uid %s@%s", tr->uid, raddr);
}
if(findkey(KEYDB, tr->hostid, hkey) == 0){
/* make one up so caller doesn't know it was wrong */
mkkey(hkey);
if(debug)
syslog(0, AUTHLOG, "cr-fail hostid %s %s@%s", tr->hostid,
tr->uid, raddr);
}
/*
* challenge-response
*/
memset(buf, 0, sizeof(buf));
buf[0] = AuthOK;
chal = lnrand(MAXNETCHAL);
sprint(buf+1, "%lud", chal);
if(write(1, buf, NETCHLEN+1) < 0)
exits(0);
if(readn(0, buf, NETCHLEN) < 0)
exits(0);
if(!(key && netcheck(key, chal, buf))
&& !(netkey && netcheck(netkey, chal, buf))
&& (err = secureidcheck(tr->uid, buf)) != nil){
replyerror("cr-fail %s %s %s", err, tr->uid, raddr);
logfail(tr->uid);
if(debug)
syslog(0, AUTHLOG, "cr-fail %s@%s(%s): bad resp",
tr->uid, tr->hostid, raddr);
return;
}
succeed(tr->uid);
/*
* reply with ticket & authenticator
*/
if(tickauthreply(tr, hkey) < 0){
if(debug)
syslog(0, AUTHLOG, "cr-fail %s@%s(%s): hangup",
tr->uid, tr->hostid, raddr);
exits(0);
}
if(debug)
syslog(0, AUTHLOG, "cr-ok %s@%s(%s)",
tr->uid, tr->hostid, raddr);
}
void
changepasswd(Ticketreq *tr)
{
Ticket t;
char tbuf[TICKETLEN+1];
char prbuf[PASSREQLEN];
Passwordreq pr;
char okey[DESKEYLEN], nkey[DESKEYLEN];
char *err;
if(findkey(KEYDB, tr->uid, okey) == 0){
/* make one up so caller doesn't know it was wrong */
mkkey(okey);
syslog(0, AUTHLOG, "cp-fail uid %s", raddr);
}
/* send back a ticket with a new key */
memmove(t.chal, tr->chal, CHALLEN);
mkkey(t.key);
tbuf[0] = AuthOK;
t.num = AuthTp;
safecpy(t.cuid, tr->uid, sizeof(t.cuid));
safecpy(t.suid, tr->uid, sizeof(t.suid));
convT2M(&t, tbuf+1, okey);
write(1, tbuf, sizeof(tbuf));
/* loop trying passwords out */
for(;;){
if(readn(0, prbuf, PASSREQLEN) < 0)
exits(0);
convM2PR(prbuf, &pr, t.key);
if(pr.num != AuthPass){
replyerror("protocol botch1: %s", raddr);
exits(0);
}
passtokey(nkey, pr.old);
if(memcmp(nkey, okey, DESKEYLEN)){
replyerror("protocol botch2: %s", raddr);
continue;
}
if(*pr.new){
err = okpasswd(pr.new);
if(err){
replyerror("%s %s", err, raddr);
continue;
}
passtokey(nkey, pr.new);
}
if(pr.changesecret && setsecret(KEYDB, tr->uid, pr.secret) == 0){
replyerror("can't write secret %s", raddr);
continue;
}
if(*pr.new && setkey(KEYDB, tr->uid, nkey) == 0){
replyerror("can't write key %s", raddr);
continue;
}
break;
}
prbuf[0] = AuthOK;
write(1, prbuf, 1);
succeed(tr->uid);
return;
}
void
http(Ticketreq *tr)
{
Ticket t;
char tbuf[TICKETLEN+1];
char key[DESKEYLEN];
char *p;
Biobuf *b;
int n;
n = strlen(tr->uid);
b = Bopen("/sys/lib/httppasswords", OREAD);
if(b == nil){
replyerror("no password file", raddr);
return;
}
/* find key */
for(;;){
p = Brdline(b, '\n');
if(p == nil)
break;
p[Blinelen(b)-1] = 0;
if(strncmp(p, tr->uid, n) == 0)
if(p[n] == ' ' || p[n] == '\t'){
p += n;
break;
}
}
Bterm(b);
if(p == nil) {
randombytes((uchar*)key, DESKEYLEN);
} else {
while(*p == ' ' || *p == '\t')
p++;
passtokey(key, p);
}
/* send back a ticket encrypted with the key */
randombytes((uchar*)t.chal, CHALLEN);
mkkey(t.key);
tbuf[0] = AuthOK;
t.num = AuthHr;
safecpy(t.cuid, tr->uid, sizeof(t.cuid));
safecpy(t.suid, tr->uid, sizeof(t.suid));
convT2M(&t, tbuf+1, key);
write(1, tbuf, sizeof(tbuf));
}
static char*
domainname(void)
{
static char sysname[Maxpath];
static char *domain;
int n;
if(domain)
return domain;
if(*sysname)
return sysname;
domain = csgetvalue(0, "sys", sysname, "dom", nil);
if(domain)
return domain;
n = readfile("/dev/sysname", sysname, sizeof(sysname)-1);
if(n < 0){
strcpy(sysname, "kremvax");
return sysname;
}
sysname[n] = 0;
return sysname;
}
static int
h2b(char c)
{
if(c >= '0' && c <= '9')
return c - '0';
if(c >= 'A' && c <= 'F')
return c - 'A' + 10;
if(c >= 'a' && c <= 'f')
return c - 'a' + 10;
return 0;
}
void
apop(Ticketreq *tr, int type)
{
int challen, i, tries;
char *secret, *hkey, *p;
Ticketreq treq;
DigestState *s;
char sbuf[SECRETLEN], hbuf[DESKEYLEN];
char tbuf[TICKREQLEN];
char buf[MD5dlen*2];
uchar digest[MD5dlen], resp[MD5dlen];
ulong rb[4];
char chal[256];
USED(tr);
/*
* Create a challenge and send it.
*/
randombytes((uchar*)rb, sizeof(rb));
p = chal;
p += snprint(p, sizeof(chal), "<%lux%lux.%lux%lux@%s>",
rb[0], rb[1], rb[2], rb[3], domainname());
challen = p - chal;
print("%c%-5d%s", AuthOKvar, challen, chal);
/* give user a few attempts */
for(tries = 0; ; tries++) {
/*
* get ticket request
*/
if(readn(0, tbuf, TICKREQLEN) < 0)
exits(0);
convM2TR(tbuf, &treq);
tr = &treq;
if(tr->type != type)
exits(0);
/*
* read response
*/
if(readn(0, buf, MD5dlen*2) < 0)
exits(0);
for(i = 0; i < MD5dlen; i++)
resp[i] = (h2b(buf[2*i])<<4)|h2b(buf[2*i+1]);
/*
* lookup
*/
secret = findsecret(KEYDB, tr->uid, sbuf);
hkey = findkey(KEYDB, tr->hostid, hbuf);
if(hkey == 0 || secret == 0){
replyerror("apop-fail bad response %s", raddr);
logfail(tr->uid);
if(tries > 5)
return;
continue;
}
/*
* check for match
*/
if(type == AuthCram){
hmac_md5((uchar*)chal, challen,
(uchar*)secret, strlen(secret),
digest, nil);
} else {
s = md5((uchar*)chal, challen, 0, 0);
md5((uchar*)secret, strlen(secret), digest, s);
}
if(memcmp(digest, resp, MD5dlen) != 0){
replyerror("apop-fail bad response %s", raddr);
logfail(tr->uid);
if(tries > 5)
return;
continue;
}
break;
}
succeed(tr->uid);
/*
* reply with ticket & authenticator
*/
if(tickauthreply(tr, hkey) < 0)
exits(0);
if(debug){
if(type == AuthCram)
syslog(0, AUTHLOG, "cram-ok %s %s", tr->uid, raddr);
else
syslog(0, AUTHLOG, "apop-ok %s %s", tr->uid, raddr);
}
}
enum {
VNCchallen= 16,
};
/* VNC reverses the bits of each byte before using as a des key */
uchar swizzletab[256] = {
0x0, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
0x8, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
0x4, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
0xc, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
0x2, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
0xa, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
0x6, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
0xe, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
0x1, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
0x9, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
0x5, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
0xd, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
0x3, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
0xb, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
0x7, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
0xf, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff,
};
void
vnc(Ticketreq *tr)
{
uchar chal[VNCchallen+6];
uchar reply[VNCchallen];
char *secret, *hkey;
char sbuf[SECRETLEN], hbuf[DESKEYLEN];
DESstate s;
int i;
/*
* Create a challenge and send it.
*/
randombytes(chal+6, VNCchallen);
chal[0] = AuthOKvar;
sprint((char*)chal+1, "%-5d", VNCchallen);
if(write(1, chal, sizeof(chal)) != sizeof(chal))
return;
/*
* lookup keys (and swizzle bits)
*/
memset(sbuf, 0, sizeof(sbuf));
secret = findsecret(KEYDB, tr->uid, sbuf);
if(secret == 0){
randombytes((uchar*)sbuf, sizeof(sbuf));
secret = sbuf;
}
for(i = 0; i < 8; i++)
secret[i] = swizzletab[(uchar)secret[i]];
hkey = findkey(KEYDB, tr->hostid, hbuf);
if(hkey == 0){
randombytes((uchar*)hbuf, sizeof(hbuf));
hkey = hbuf;
}
/*
* get response
*/
if(readn(0, reply, sizeof(reply)) != sizeof(reply))
return;
/*
* decrypt response and compare
*/
setupDESstate(&s, (uchar*)secret, nil);
desECBdecrypt(reply, sizeof(reply), &s);
if(memcmp(reply, chal+6, VNCchallen) != 0){
replyerror("vnc-fail bad response %s", raddr);
logfail(tr->uid);
return;
}
succeed(tr->uid);
/*
* reply with ticket & authenticator
*/
if(tickauthreply(tr, hkey) < 0)
exits(0);
if(debug)
syslog(0, AUTHLOG, "vnc-ok %s %s", tr->uid, raddr);
}
void
chap(Ticketreq *tr)
{
char *secret, *hkey;
DigestState *s;
char sbuf[SECRETLEN], hbuf[DESKEYLEN];
uchar digest[MD5dlen];
char chal[CHALLEN];
OChapreply reply;
/*
* Create a challenge and send it.
*/
randombytes((uchar*)chal, sizeof(chal));
write(1, chal, sizeof(chal));
/*
* get chap reply
*/
if(readn(0, &reply, sizeof(reply)) < 0)
exits(0);
safecpy(tr->uid, reply.uid, sizeof(tr->uid));
/*
* lookup
*/
secret = findsecret(KEYDB, tr->uid, sbuf);
hkey = findkey(KEYDB, tr->hostid, hbuf);
if(hkey == 0 || secret == 0){
replyerror("chap-fail bad response %s", raddr);
logfail(tr->uid);
exits(0);
}
/*
* check for match
*/
s = md5(&reply.id, 1, 0, 0);
md5((uchar*)secret, strlen(secret), 0, s);
md5((uchar*)chal, sizeof(chal), digest, s);
if(memcmp(digest, reply.resp, MD5dlen) != 0){
replyerror("chap-fail bad response %s", raddr);
logfail(tr->uid);
exits(0);
}
succeed(tr->uid);
/*
* reply with ticket & authenticator
*/
if(tickauthreply(tr, hkey) < 0)
exits(0);
if(debug)
syslog(0, AUTHLOG, "chap-ok %s %s", tr->uid, raddr);
}
void
printresp(uchar resp[MSresplen])
{
char buf[200], *p;
int i;
p = buf;
for(i=0; i<MSresplen; i++)
p += sprint(p, "%.2ux ", resp[i]);
syslog(0, AUTHLOG, "resp = %s", buf);
}
enum {
MsvAvEOL = 0,
MsvAvNbComputerName,
MsvAvNbDomainName,
MsvAvDnsComputerName,
MsvAvDnsomainName,
};
char*
getname(int id, uchar *ntblob, int ntbloblen, char *buf, int nbuf)
{
int aid, alen, i;
uchar *p, *e;
char *d;
Rune r;
d = buf;
p = ntblob+8+8+8+4; /* AvPair offset */
e = ntblob+ntbloblen;
while(p+4 <= e){
aid = *p++;
aid |= *p++ << 8;
alen = *p++;
alen |= *p++ << 8;
if(p+alen > e)
break;
if(aid == id){
for(i=0; i+1 < alen && d-buf < nbuf-(UTFmax+1); i+=2){
r = p[i] | p[i+1]<<8;
d += runetochar(d, &r);
}
break;
}
p += alen;
}
*d = '\0';
return buf;
}
static uchar ntblobsig[] = {0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
void
mschap(Ticketreq *tr)
{
char *secret, *hkey;
char sbuf[SECRETLEN], hbuf[DESKEYLEN], windom[128];
uchar chal[CHALLEN], ntblob[1024];
uchar hash[MShashlen];
uchar hash2[MShashlen];
uchar resp[MSresplen];
OMSchapreply reply;
int dupe, lmok, ntok, ntbloblen;
DigestState *s;
uchar digest[SHA1dlen];
/*
* Create a challenge and send it.
*/
randombytes((uchar*)chal, sizeof(chal));
write(1, chal, sizeof(chal));
/*
* get chap reply
*/
if(readn(0, &reply, OMSCHAPREPLYLEN) < 0)
exits(0);
/*
* CIFS/NTLMv2 uses variable length NT response.
*/
ntbloblen = 0;
if(memcmp(reply.NTresp+16, ntblobsig, sizeof(ntblobsig)) == 0){
/* Version[1], HiVision[1], Z[6] */
ntbloblen += 1+1+6;
memmove(ntblob, reply.NTresp+16, ntbloblen);
/* Time[8], CC[8], Z[4] */
if(readn(0, ntblob+ntbloblen, 8+8+4) < 0)
exits(0);
ntbloblen += 8+8+4;
/* variable AvPairs */
for(;;){
int len, id;
if(ntbloblen > sizeof(ntblob)-4)
exits(0);
/* AvId[2], AvLen[2], Vairable[AvLen] */
if(readn(0, ntblob+ntbloblen, 4) < 0)
exits(0);
id = ntblob[ntbloblen+0] | ntblob[ntbloblen+1]<<8;
len = ntblob[ntbloblen+2] | ntblob[ntbloblen+3]<<8;
ntbloblen += 4;
if(ntbloblen+len > sizeof(ntblob))
exits(0);
if(readn(0, ntblob+ntbloblen, len) < 0)
exits(0);
ntbloblen += len;
if(id == MsvAvEOL)
break;
}
/* Z[4] */
if(ntbloblen > sizeof(ntblob)-4)
exits(0);
if(readn(0, ntblob+ntbloblen, 4) < 0)
exits(0);
ntbloblen += 4;
}
safecpy(tr->uid, reply.uid, sizeof(tr->uid));
/*
* lookup
*/
secret = findsecret(KEYDB, tr->uid, sbuf);
hkey = findkey(KEYDB, tr->hostid, hbuf);
if(hkey == 0 || secret == 0){
replyerror("mschap-fail bad response %s/%s(%s)",
tr->uid, tr->hostid, raddr);
logfail(tr->uid);
exits(0);
}
if(ntbloblen > 0){
getname(MsvAvNbDomainName, ntblob, ntbloblen, windom, sizeof(windom));
for(;;){
ntv2hash(hash, secret, tr->uid, windom);
/*
* LmResponse = Cat(HMAC_MD5(LmHash, Cat(SC, CC)), CC)
*/
s = hmac_md5(chal, 8, hash, MShashlen, nil, nil);
hmac_md5((uchar*)reply.LMresp+16, 8, hash, MShashlen, resp, s);
lmok = memcmp(resp, reply.LMresp, 16) == 0;
/*
* NtResponse = Cat(HMAC_MD5(NtHash, Cat(SC, NtBlob)), NtBlob)
*/
s = hmac_md5(chal, 8, hash, MShashlen, nil, nil);
hmac_md5(ntblob, ntbloblen, hash, MShashlen, resp, s);
ntok = memcmp(resp, reply.NTresp, 16) == 0;
if(lmok || ntok || windom[0] == '\0')
break;
windom[0] = '\0'; /* try NIL domain */
}
dupe = 0;
} else {
lmhash(hash, secret);
mschalresp(resp, hash, chal);
lmok = memcmp(resp, reply.LMresp, MSresplen) == 0;
nthash(hash, secret);
mschalresp(resp, hash, chal);
ntok = memcmp(resp, reply.NTresp, MSresplen) == 0;
dupe = memcmp(reply.LMresp, reply.NTresp, MSresplen) == 0;
}
/*
* It is valid to send the same response in both the LM and NTLM
* fields provided one of them is correct, if neither matches,
* or the two fields are different and either fails to match,
* the whole sha-bang fails.
*
* This is an improvement in security as it allows clients who
* wish to do NTLM auth (which is insecure) not to send
* LM tokens (which is very insecure).
*
* Windows servers supports clients doing this also though
* windows clients don't seem to use the feature.
*/
if((!ntok && !lmok) || ((!ntok || !lmok) && !dupe)){
replyerror("mschap-fail bad response %s/%s(%s) %d,%d,%d",
tr->uid, tr->hostid, raddr, dupe, lmok, ntok);
logfail(tr->uid);
exits(0);
}
succeed(tr->uid);
/*
* reply with ticket & authenticator
*/
if(tickauthreply(tr, hkey) < 0)
exits(0);
if(debug)
replyerror("mschap-ok %s/%s(%s)", tr->uid, tr->hostid, raddr);
nthash(hash, secret);
md4(hash, 16, hash2, 0);
s = sha1(hash2, 16, 0, 0);
sha1(hash2, 16, 0, s);
sha1(chal, 8, digest, s);
if(write(1, digest, 16) < 0)
exits(0);
}
void
nthash(uchar hash[MShashlen], char *passwd)
{
DigestState *ds;
uchar b[2];
Rune r;
ds = md4(nil, 0, nil, nil);
while(*passwd){
passwd += chartorune(&r, passwd);
b[0] = r & 0xff;
b[1] = r >> 8;
md4(b, 2, nil, ds);
}
md4(nil, 0, hash, ds);
}
void
ntv2hash(uchar hash[MShashlen], char *passwd, char *user, char *dom)
{
uchar v1hash[MShashlen];
DigestState *ds;
uchar b[2];
Rune r;
nthash(v1hash, passwd);
/*
* Some documentation insists that the username must be forced to
* uppercase, but the domain name should not be. Other shows both
* being forced to uppercase. I am pretty sure this is irrevevant as the
* domain name passed from the remote server always seems to be in
* uppercase already.
*/
ds = hmac_md5(nil, 0, v1hash, sizeof(v1hash), nil, nil);
while(*user){
user += chartorune(&r, user);
r = toupperrune(r);
b[0] = r & 0xff;
b[1] = r >> 8;
hmac_md5(b, 2, v1hash, sizeof(v1hash), nil, ds);
}
while(*dom){
dom += chartorune(&r, dom);
b[0] = r & 0xff;
b[1] = r >> 8;
hmac_md5(b, 2, v1hash, sizeof(v1hash), nil, ds);
}
hmac_md5(nil, 0, v1hash, sizeof(v1hash), hash, ds);
}
void
lmhash(uchar hash[MShashlen], char *passwd)
{
uchar buf[14];
char *stdtext = "KGS!@#$%";
int i;
memset(buf, 0, sizeof(buf));
strncpy((char*)buf, passwd, sizeof(buf));
for(i=0; i<sizeof(buf); i++)
if(buf[i] >= 'a' && buf[i] <= 'z')
buf[i] += 'A' - 'a';
memcpy(hash, stdtext, 8);
memcpy(hash+8, stdtext, 8);
desencrypt(hash, buf);
desencrypt(hash+8, buf+7);
}
void
mschalresp(uchar resp[MSresplen], uchar hash[MShashlen], uchar chal[MSchallen])
{
int i;
uchar buf[21];
memset(buf, 0, sizeof(buf));
memcpy(buf, hash, MShashlen);
for(i=0; i<3; i++) {
memmove(resp+i*MSchallen, chal, MSchallen);
desencrypt(resp+i*MSchallen, buf+i*7);
}
}
void
desencrypt(uchar data[8], uchar key[7])
{
ulong ekey[32];
key_setup(key, ekey);
block_cipher(ekey, data, 0);
}
/*
* return true of the speaker may speak for the user
*
* a speaker may always speak for himself/herself
*/
int
speaksfor(char *speaker, char *user)
{
Ndbtuple *tp, *ntp;
Ndbs s;
int ok;
char notuser[Maxpath];
if(strcmp(speaker, user) == 0)
return 1;
if(db == 0)
return 0;
tp = ndbsearch(db, &s, "hostid", speaker);
if(tp == 0)
return 0;
ok = 0;
snprint(notuser, sizeof notuser, "!%s", user);
for(ntp = tp; ntp; ntp = ntp->entry)
if(strcmp(ntp->attr, "uid") == 0){
if(strcmp(ntp->val, notuser) == 0){
ok = 0;
break;
}
if(*ntp->val == '*' || strcmp(ntp->val, user) == 0)
ok = 1;
}
ndbfree(tp);
return ok;
}
/*
* return an error reply
*/
void
replyerror(char *fmt, ...)
{
char buf[AERRLEN+1];
va_list arg;
memset(buf, 0, sizeof(buf));
va_start(arg, fmt);
vseprint(buf + 1, buf + sizeof(buf), fmt, arg);
va_end(arg);
buf[AERRLEN] = 0;
buf[0] = AuthErr;
write(1, buf, AERRLEN+1);
syslog(0, AUTHLOG, buf+1);
}
void
getraddr(char *dir)
{
int n;
char *cp;
char file[Maxpath];
raddr[0] = 0;
snprint(file, sizeof(file), "%s/remote", dir);
n = readfile(file, raddr, sizeof(raddr)-1);
if(n < 0)
return;
raddr[n] = 0;
cp = strchr(raddr, '\n');
if(cp)
*cp = 0;
cp = strchr(raddr, '!');
if(cp)
*cp = 0;
}
void
mkkey(char *k)
{
randombytes((uchar*)k, DESKEYLEN);
}
void
randombytes(uchar *buf, int len)
{
int i;
if(readfile("/dev/random", (char*)buf, len) >= 0)
return;
for(i = 0; i < len; i++)
buf[i] = rand();
}
/*
* reply with ticket and authenticator
*/
int
tickauthreply(Ticketreq *tr, char *hkey)
{
Ticket t;
Authenticator a;
char buf[TICKETLEN+AUTHENTLEN+1];
memset(&t, 0, sizeof(t));
memmove(t.chal, tr->chal, CHALLEN);
safecpy(t.cuid, tr->uid, sizeof t.cuid);
safecpy(t.suid, tr->uid, sizeof t.suid);
mkkey(t.key);
buf[0] = AuthOK;
t.num = AuthTs;
convT2M(&t, buf+1, hkey);
memmove(a.chal, t.chal, CHALLEN);
a.num = AuthAc;
a.id = 0;
convA2M(&a, buf+TICKETLEN+1, t.key);
if(write(1, buf, TICKETLEN+AUTHENTLEN+1) < 0)
return -1;
return 0;
}
void
safecpy(char *to, char *from, int len)
{
strncpy(to, from, len);
to[len-1] = 0;
}