new auth

src/cmd/auth/factotum/p9any.c

@@ -0,0 +1,272 @@
+#include "std.h"
+#include "dat.h"
+
+/*
+ * p9any - protocol negotiator
+ *
+ * Protocol:
+ *	S->C: v.2 proto@dom proto@dom proto@dom... NUL
+ *	C->S: proto dom NUL
+ *	[negotiated proto continues]
+ */
+ 
+extern Proto p9sk1, p9sk2, p9cr;
+
+static Proto* okproto[] =
+{
+	&p9sk1,
+	nil,
+};
+
+static int
+rolecall(Role *r, char *name, Conv *c)
+{
+	for(; r->name; r++)
+		if(strcmp(r->name, name) == 0)
+			return (*r->fn)(c);
+	werrstr("unknown role");
+	return -1;
+}
+
+static int
+hasnul(void *v, int n)
+{
+	char *c;
+
+	c = v;
+	if(n > 0 && c[n-1] == '\0')
+		return n;
+	else
+		return AuthRpcMax;
+}
+
+static int
+p9anyserver(Conv *c)
+{
+	char *s, *dom;
+	int i, j, n, m, ret;
+	char *tok[3];
+	Attr *attr;
+	Key *k;
+
+	ret = -1;
+	s = estrdup("v.2");
+	n = 0;
+	attr = delattr(copyattr(c->attr), "proto");
+
+	for(i=0; i<ring.nkey; i++){
+		k = ring.key[i];
+		for(j=0; okproto[j]; j++)
+			if(k->proto == okproto[j]
+			&& (dom = strfindattr(k->attr, "dom")) != nil
+			&& matchattr(attr, k->attr, k->privattr)){
+				s = estrappend(s, " %s@%s", k->proto->name, dom);
+				n++;
+			}
+	}
+
+	if(n == 0){
+		werrstr("no valid keys");
+		goto out;
+	}
+
+	c->state = "write offer";
+	if(convwrite(c, s, strlen(s)+1) < 0)
+		goto out;
+	free(s);
+	s = nil;
+
+	c->state = "read choice";
+	if(convreadfn(c, hasnul, &s) < 0)
+		goto out;
+
+	m = tokenize(s, tok, nelem(tok));
+	if(m != 2){
+		werrstr("bad protocol message");
+		goto out;
+	}
+
+	for(i=0; okproto[i]; i++)
+		if(strcmp(okproto[i]->name, tok[0]) == 0)
+			break;
+	if(!okproto[i]){
+		werrstr("bad chosen protocol %q", tok[0]);
+		goto out;
+	}
+
+	c->state = "write ok";
+	if(convwrite(c, "OK\0", 3) < 0)
+		goto out;
+
+	c->state = "start choice";
+	attr = addattr(attr, "proto=%q dom=%q", tok[0], tok[1]);
+	free(c->attr);
+	c->attr = attr;
+	attr = nil;
+	c->proto = okproto[i];
+
+	if(rolecall(c->proto->roles, "server", c) < 0){
+		werrstr("%s: %r", tok[0]);
+		goto out;
+	}
+
+	ret = 0;
+	
+out:
+	free(s);
+	freeattr(attr);
+	return ret;
+}
+
+static int
+p9anyclient(Conv *c)
+{
+	char *s, **f, *tok[20], ok[3], *q, *user, *dom, *choice;
+	int i, n, ret, version;
+	Key *k;
+	Attr *attr;
+	Proto *p;
+
+	ret = -1;
+	s = nil;
+	k = nil;
+
+	user = strfindattr(c->attr, "user");
+	dom = strfindattr(c->attr, "dom");
+
+	/*
+	 * if the user is the factotum owner, any key will do.
+	 * if not, then if we have a speakfor key,
+	 * we will only vouch for the user's local identity.
+	 *
+	 * this logic is duplicated in p9sk1.c
+	 */
+	attr = delattr(copyattr(c->attr), "role");
+	attr = delattr(attr, "proto");
+	if(strcmp(c->sysuser, owner) == 0)
+		attr = addattr(attr, "role=client");
+	else if(user==nil || strcmp(c->sysuser, user)==0){
+		attr = delattr(attr, "user");
+		attr = addattr(attr, "role=speakfor");
+	}else{
+		werrstr("will not authenticate for %q as %q", c->sysuser, user);
+		goto out;
+	}
+
+	c->state = "read offer";
+	if(convreadfn(c, hasnul, &s) < 0)
+		goto out;
+
+	c->state = "look for keys";
+	n = tokenize(s, tok, nelem(tok));
+	f = tok;
+	version = 1;
+	if(n > 0 && memcmp(f[0], "v.", 2) == 0){
+		version = atoi(f[0]+2);
+		if(version != 2){
+			werrstr("unknown p9any version: %s", f[0]);
+			goto out;
+		}
+		f++;
+		n--;
+	}
+
+	/* look for keys that don't need confirmation */
+	for(i=0; i<n; i++){
+		if((q = strchr(f[i], '@')) == nil)
+			continue;
+		if(dom && strcmp(q+1, dom) != 0)
+			continue;
+		*q++ = '\0';
+		if((k = keylookup("%A proto=%q dom=%q", attr, f[i], q))
+		&& strfindattr(k->attr, "confirm") == nil)
+			goto found;
+		*--q = '@';
+	}
+
+	/* look for any keys at all */
+	for(i=0; i<n; i++){
+		if((q = strchr(f[i], '@')) == nil)
+			continue;
+		if(dom && strcmp(q+1, dom) != 0)
+			continue;
+		*q++ = '\0';
+		if(k = keylookup("%A proto=%q dom=%q", attr, f[i], q))
+			goto found;
+		*--q = '@';
+	}
+
+	/* ask for new keys */
+	c->state = "ask for keys";
+	for(i=0; i<n; i++){
+		if((q = strchr(f[i], '@')) == nil)
+			continue;
+		if(dom && strcmp(q+1, dom) != 0)
+			continue;
+		*q++ = '\0';
+		p = protolookup(f[i]);
+		if(p == nil || p->keyprompt == nil){
+			*--q = '@';
+			continue;
+		}
+		if(k = keyfetch(c, "%A proto=%q dom=%q %s", attr, f[i], q, p->keyprompt))
+			goto found;
+		*--q = '@';
+	}
+
+	/* nothing worked */
+	werrstr("unable to find common key");
+	goto out;
+
+found:
+	/* f[i] is the chosen protocol, q the chosen domain */
+	attr = addattr(attr, "proto=%q dom=%q", f[i], q);
+	c->state = "write choice";
+	
+	/* have a key: go for it */
+	choice = estrappend(nil, "%q %q", f[i], q);
+	if(convwrite(c, choice, strlen(choice)+1) < 0){
+		free(choice);
+		goto out;
+	}
+	free(choice);
+
+	if(version == 2){
+		c->state = "read ok";
+		if(convread(c, ok, 3) < 0 || memcmp(ok, "OK\0", 3) != 0)
+			goto out;
+	}
+
+	c->state = "start choice";
+	c->proto = protolookup(f[i]);
+	freeattr(c->attr);
+	c->attr = attr;
+	attr = nil;
+
+	if(rolecall(c->proto->roles, "client", c) < 0){
+		werrstr("%s: %r", c->proto->name);
+		goto out;
+	}
+
+	ret = 0;
+
+out:
+	keyclose(k);
+	freeattr(attr);
+	free(s);
+	return ret;
+}
+
+static Role
+p9anyroles[] = 
+{
+	"client",	p9anyclient,
+	"server",	p9anyserver,
+	0
+};
+
+Proto p9any = {
+.name=		"p9any",
+.roles=		p9anyroles,
+};
+