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#include "imap4d.h"
#include <libsec.h>
static char Ebadch[] = "can't get challenge";
static char Ecantstart[] = "can't initialize mail system: %r";
static char Ecancel[] = "client cancelled authentication";
static char Ebadau[] = "login failed";
/*
* hack to allow smtp forwarding.
* hide the peer IP address under a rock in the ratifier FS.
*/
void
enableforwarding(void)
{
char buf[64], peer[64], *p;
int fd;
ulong now;
static ulong last;
if(remote == nil)
return;
now = time(0);
if(now < last + 5*60)
return;
last = now;
fd = open("/srv/ratify", ORDWR);
if(fd < 0)
return;
if(!mount(fd, -1, "/mail/ratify", MBEFORE, "")){
close(fd);
return;
}
close(fd);
strncpy(peer, remote, sizeof peer);
peer[sizeof peer - 1] = 0;
p = strchr(peer, '!');
if(p != nil)
*p = 0;
snprint(buf, sizeof buf, "/mail/ratify/trusted/%s#32", peer);
/*
* if the address is already there and the user owns it,
* remove it and recreate it to give him a new time quanta.
*/
if(access(buf, 0) >= 0 && remove(buf) < 0)
return;
fd = create(buf, OREAD, 0666);
if(fd >= 0)
close(fd);
}
void
setupuser(AuthInfo *ai)
{
int pid;
Waitmsg *w;
if(ai){
strecpy(username, username + sizeof username, ai->cuid);
if(auth_chuid(ai, nil) == -1)
bye("user auth failed: %r");
auth_freeAI(ai);
}else
strecpy(username, username + sizeof username, getuser());
if(strcmp(username, "none") == 0 || newns(username, 0) == -1)
bye("user login failed: %r");
if(binupas){
if(bind(binupas, "/bin/upas", MREPL) > 0)
ilog("bound %s on /bin/upas", binupas);
else
bye("bind %s failed: %r", binupas);
}
/*
* hack to allow access to outgoing smtp forwarding
*/
enableforwarding();
snprint(mboxdir, Pathlen, "/mail/box/%s", username);
if(mychdir(mboxdir) < 0)
bye("can't open user's mailbox");
switch(pid = fork()){
case -1:
bye(Ecantstart);
break;
case 0:
if(!strstr(argv0, "8.out"))
execl("/bin/upas/fs", "upas/fs", "-np", nil);
else{
ilog("using /sys/src/cmd/upas/fs/8.out");
execl("/sys/src/cmd/upas/fs/8.out", "upas/fs", "-np", nil);
}
_exits(0);
break;
default:
break;
}
if((w = wait()) == nil || w->pid != pid || w->msg[0] != 0)
bye(Ecantstart);
free(w);
}
static char*
authread(int *len)
{
char *t;
int n;
t = Brdline(&bin, '\n');
n = Blinelen(&bin);
if(n < 2)
return nil;
n--;
if(t[n-1] == '\r')
n--;
t[n] = 0;
if(n == 0 || strcmp(t, "*") == 0)
return nil;
*len = n;
return t;
}
static char*
authresp(void)
{
char *s, *t;
int n;
t = authread(&n);
if(t == nil)
return nil;
s = binalloc(&parsebin, n + 1, 1);
n = dec64((uchar*)s, n, t, n);
s[n] = 0;
return s;
}
/*
* rfc 2195 cram-md5 authentication
*/
char*
cramauth(void)
{
char *s, *t;
AuthInfo *ai;
Chalstate *cs;
if((cs = auth_challenge("proto=cram role=server")) == nil)
return Ebadch;
Bprint(&bout, "+ %.*[\r\n", cs->nchal, cs->chal);
if(Bflush(&bout) < 0)
writeerr();
s = authresp();
if(s == nil)
return Ecancel;
t = strchr(s, ' ');
if(t == nil)
return Ebadch;
*t++ = 0;
strncpy(username, s, Userlen);
username[Userlen - 1] = 0;
cs->user = username;
cs->resp = t;
cs->nresp = strlen(t);
if((ai = auth_response(cs)) == nil)
return Ebadau;
auth_freechal(cs);
setupuser(ai);
return nil;
}
char*
crauth(char *u, char *p)
{
char response[64];
AuthInfo *ai;
static char nchall[64];
static Chalstate *ch;
again:
if(ch == nil){
if(!(ch = auth_challenge("proto=p9cr role=server user=%q", u)))
return Ebadch;
snprint(nchall, 64, " encrypt challenge: %s", ch->chal);
return nchall;
} else {
strncpy(response, p, 64);
ch->resp = response;
ch->nresp = strlen(response);
ai = auth_response(ch);
auth_freechal(ch);
ch = nil;
if(ai == nil)
goto again;
setupuser(ai);
return nil;
}
}
char*
passauth(char *u, char *secret)
{
char response[2*MD5dlen + 1];
uchar digest[MD5dlen];
AuthInfo *ai;
Chalstate *cs;
if((cs = auth_challenge("proto=cram role=server")) == nil)
return Ebadch;
hmac_md5((uchar*)cs->chal, strlen(cs->chal),
(uchar*)secret, strlen(secret), digest, nil);
snprint(response, sizeof(response), "%.*H", MD5dlen, digest);
cs->user = u;
cs->resp = response;
cs->nresp = strlen(response);
ai = auth_response(cs);
if(ai == nil)
return Ebadau;
auth_freechal(cs);
setupuser(ai);
return nil;
}
static int
niltokenize(char *buf, int n, char **f, int nelemf)
{
int i, nf;
f[0] = buf;
nf = 1;
for(i = 0; i < n - 1; i++)
if(buf[i] == 0){
f[nf++] = buf + i + 1;
if(nf == nelemf)
break;
}
return nf;
}
char*
plainauth(char *ch)
{
char buf[256*3 + 2], *f[4];
int n, nf;
if(ch == nil){
Bprint(&bout, "+ \r\n");
if(Bflush(&bout) < 0)
writeerr();
ch = authread(&n);
}
if(ch == nil || strlen(ch) == 0)
return Ecancel;
n = dec64((uchar*)buf, sizeof buf, ch, strlen(ch));
nf = niltokenize(buf, n, f, nelem(f));
if(nf != 3)
return Ebadau;
return passauth(f[1], f[2]);
}
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