x20090325-1554

1 files changed, 440 insertions, 0 deletions

diff --git a/emu/port/devsign.c b/emu/port/devsign.c
new file mode 100644
index 00000000..ba44e286
--- /dev/null
+++ b/emu/port/devsign.c
@@ -0,0 +1,440 @@
+#include	"dat.h"
+#include	"fns.h"
+#include	"error.h"
+#include	"interp.h"
+#include	<isa.h>
+#include	"runt.h"
+#include "mp.h"
+#include "libsec.h"
+#include "../../libkeyring/keys.h"
+
+/*
+ * experimental version of signed modules
+ */
+
+enum
+{
+	Qdir,
+	Qkey,
+	Qctl,
+
+	Maxkey = 2048
+};
+
+static Dirtab signdir[] =
+{
+	".",		{Qdir, 0, QTDIR},	0,	DMDIR|0555,
+	"signerkey",	{Qkey},	0,			0644,
+	"signerctl",	{Qctl},	0,			0600,
+};
+
+typedef struct Get Get;
+struct Get {
+	uchar*	p;
+	uchar*	ep;
+};
+
+#define	G32(b)	((b[0]<<24)|(b[1]<<16)|(b[2]<<8)|b[3])
+
+static	int	vc(Get*);
+static	int	vs(void*, int, Get*, int);
+static Signerkey* findsignerkey(Skeyset*, char*, int, char*);
+extern vlong		osusectime(void);
+
+int
+verifysigner(uchar *sign, int len, uchar *data, ulong ndata)
+{
+	Get sig;
+	int alg;
+	ulong issued, expires, now;
+	int footprint, r, n;
+	uchar buf[128], digest[SHA1dlen];
+	DigestState *ds;
+	volatile struct {mpint* b;} b;
+	volatile struct {mpint* s;} s;
+	SigAlgVec *sa;
+	Signerkey *key;
+	Skeyset *sigs;
+
+	/* alg[1] issued[4] expires[4] footprint[2] signer[n] sig[m] */
+	sigs = up->env->sigs;
+	if(sigs == nil)
+		return 1;	/* not enforcing signed modules */
+	sig.p = sign;
+	sig.ep = sign+len;
+	alg = vc(&sig);
+	if(alg != 2)
+		return 0;	/* we do only SHA1/RSA */
+	sa = findsigalg("rsa");
+	if(sa == nil)
+		return 0;
+	if(vs(buf, sizeof(buf), &sig, 4) < 0)
+		return 0;
+	now = osusectime()/1000000;
+	issued = G32(buf);
+	if(vs(buf, sizeof(buf), &sig, 4) < 0)
+		return 0;
+	if(issued != 0 && now < issued)
+		return 0;
+	expires = G32(buf);
+	if(expires != 0 && now >= expires)
+		return 0;
+	footprint = vc(&sig) << 8;
+	footprint |= vc(&sig);
+	if(footprint < 0)
+		return 0;
+	r = 0;
+	b.b = nil;
+	s.s = nil;
+	qlock(&sigs->l);
+	if(waserror())
+		goto out;
+	if((n = vs(buf, sizeof(buf)-NUMSIZE-1, &sig, -1)) < 0)	/* owner */
+		goto out;
+	buf[n] = 0;
+	key = findsignerkey(sigs, sa->name, footprint, (char*)buf);
+	if(key == nil)
+		goto out;
+	n += snprint((char*)buf+n, NUMSIZE, " %lud", expires);
+	ds = sha1(buf, n, nil, nil);
+	sha1(data, ndata, digest, ds);
+	b.b = betomp(digest, SHA1dlen, nil);
+	if(b.b == nil)
+		goto out;
+	s.s = betomp(sig.p, sig.ep-sig.p, nil);
+	if(s.s == nil)
+		goto out;
+	r = (*sa->verify)(b.b, s.s, key->pk);
+out:
+	qunlock(&sigs->l);
+	if(b.b != nil)
+		mpfree(b.b);
+	if(s.s != nil)
+		mpfree(s.s);
+	return r;
+}
+
+int
+mustbesigned(char *path, uchar *code, ulong length, Dir *dir)
+{
+	USED(code); USED(length);
+if(0)print("load %s: %d %C\n", path, up->env->sigs!=nil, dir==nil?'?':dir->type);
+	/* allow only signed modules and those in #/; already loaded modules are reloaded from cache */
+	return up->env->sigs != nil && (dir == nil || dir->type != '/');
+}
+
+static int
+vc(Get *g)
+{
+	return g->p < g->ep? *g->p++: -1;
+}
+
+static int
+vs(void *s, int lim, Get *g, int n)
+{
+	int nr;
+
+	if(n < 0){
+		if(g->p >= g->ep)
+			return -1;
+		n = *g->p++;
+		lim--;
+	}
+	if(n > lim)
+		return -1;
+	nr = g->ep - g->p;
+	if(n > nr)
+		return -1;
+	if(s != nil)
+		memmove(s, g->p, n);
+	g->p += n;
+	return n;
+}
+
+static char*
+cstring(char *str, char **strp)
+{
+	char *p, *s;
+	int n;
+
+	p = strchr(str, '\n');
+	if(p == 0)
+		p = str + strlen(str);
+	n = p - str;
+	s = malloc(n+1);
+	if(s == nil)
+		return nil;
+	memmove(s, str, n);
+	s[n] = 0;
+
+	if(strp){
+		if(*p)
+			p++;
+		*strp = p;
+	}
+
+	return s;
+}
+
+static SigAlgVec*
+cstrtoalg(char *str, char **strp)
+{
+	int n;
+	char *p, name[KNAMELEN];
+
+	p = strchr(str, '\n');
+	if(p == 0){
+		p = str + strlen(str);
+		if(strp)
+			*strp = p;
+	} else {
+		if(strp)
+			*strp = p+1;
+	}
+
+	n = p - str;
+	if(n >= sizeof(name))
+		return nil;
+	strncpy(name, str, n);
+	name[n] = 0;
+	return findsigalg(name);
+}
+
+static Signerkey*
+strtopk(char *buf)
+{
+	SigAlgVec *sa;
+	char *p;
+	Signerkey *key;
+
+	key = malloc(sizeof(*key));
+	if(key == nil)
+		return nil;
+	key->r.ref = 1;
+	sa = cstrtoalg(buf, &p);
+	if(sa == nil){
+		free(key);
+		return nil;
+	}
+	key->alg = sa;
+	key->pkfree = sa->pkfree;
+	key->owner = cstring(p, &p);
+	if(key->owner == nil){
+		free(key);
+		return nil;
+	}
+	key->pk = (*sa->str2pk)(p, &p);
+	if(key->pk == nil){
+		free(key->owner);
+		free(key);
+		return nil;
+	}
+	return key;
+}
+
+static Signerkey*
+findsignerkey(Skeyset *sigs, char *alg, int footprint, char *owner)
+{
+	int i;
+	Signerkey *key;
+
+	for(i=0; i<sigs->nkey; i++){
+		key = sigs->keys[i];
+		if(key->footprint == footprint &&
+		   strcmp(alg, ((SigAlgVec*)key->alg)->name) == 0 &&
+		   strcmp(key->owner, owner) == 0)
+			return key;
+	}
+	return nil;
+}
+
+static Chan*
+signattach(char *spec)
+{
+	return devattach(0x03A3, spec);	 /* L'Σ' */
+}
+
+static Walkqid*
+signwalk(Chan *c, Chan *nc, char **name, int nname)
+{
+	return devwalk(c, nc, name, nname, signdir, nelem(signdir), devgen);
+}
+
+static int
+signstat(Chan *c, uchar *db, int n)
+{
+	return devstat(c, db, n, signdir, nelem(signdir), devgen);
+}
+
+static Chan*
+signopen(Chan *c, int omode)
+{
+	if(c->qid.type & QTDIR) {
+		if(omode != OREAD)
+			error(Eisdir);
+		c->mode = openmode(omode);
+		c->flag |= COPEN;
+		c->offset = 0;
+		return c;
+	}
+
+	switch((ulong)c->qid.path){
+	case Qctl:
+		if(!iseve())
+			error(Eperm);
+		break;
+
+	case Qkey:
+		if(omode != OREAD && !iseve())
+			error(Eperm);
+		break;
+	}
+
+	c->mode = openmode(omode);
+	c->flag |= COPEN;
+	c->offset = 0;
+	return c;
+}
+
+static void
+signclose(Chan *c)
+{
+	USED(c);
+}
+
+static long
+signread(Chan *c, void *va, long n, vlong offset)
+{
+	char *buf, *p;
+	SigAlgVec *sa;
+	Skeyset *sigs;
+	Signerkey *key;
+	int i;
+
+	if(c->qid.type & QTDIR)
+		return devdirread(c, va, n, signdir, nelem(signdir), devgen);
+	sigs = up->env->sigs;
+	if(sigs == nil)
+		return 0;
+	switch((ulong)c->qid.path){
+	case Qkey:
+		buf = smalloc(Maxkey);
+		if(waserror()){
+			free(buf);
+			nexterror();
+		}
+		qlock(&sigs->l);
+		if(waserror()){
+			qunlock(&sigs->l);
+			nexterror();
+		}
+		p = buf;
+		for(i=0; i<sigs->nkey; i++){
+			key = sigs->keys[i];
+			sa = key->alg;
+			p = seprint(p, buf+Maxkey, "owner=%s alg=%s footprint=%ud expires=%lud\n",
+				key->owner, sa->name, key->footprint, key->expires);
+		}
+		poperror();
+		qunlock(&sigs->l);
+		n = readstr(offset, va, n, buf);
+		poperror();
+		free(buf);
+		return n;
+
+	case Qctl:
+		return readnum(offset, va, n, sigs->nkey, NUMSIZE);
+	}
+	return 0;
+}
+
+static long
+signwrite(Chan *c, void *va, long n, vlong offset)
+{
+	char *buf;
+	Skeyset *sigs;
+	Signerkey *okey, *key;
+	int i;
+
+	if(c->qid.type & QTDIR)
+		error(Eisdir);
+	USED(offset);
+	switch((ulong)c->qid.path){
+	case Qkey:
+		if(n >= Maxkey)
+			error(Etoobig);
+		buf = smalloc(Maxkey);
+		if(waserror()){
+			free(buf);
+			nexterror();
+		}
+		memmove(buf, va, n);
+		buf[n] = 0;
+
+		key = strtopk(buf);
+		if(key == nil)
+			error("bad key syntax");
+		poperror();
+		free(buf);
+
+		if(waserror()){
+			freeskey(key);
+			nexterror();
+		}
+		sigs = up->env->sigs;
+		if(sigs == nil){
+			sigs = malloc(sizeof(*sigs));
+			if(sigs == nil)
+				error(Enomem);
+			sigs->r.ref = 1;
+			up->env->sigs = sigs;
+		}
+		qlock(&sigs->l);
+		if(waserror()){
+			qunlock(&sigs->l);
+			nexterror();
+		}
+		for(i=0; i<sigs->nkey; i++){
+			okey = sigs->keys[i];
+			if(strcmp(okey->owner, key->owner) == 0){
+				/* replace existing key */
+				sigs->keys[i] = key;
+				freeskey(okey);
+				break;
+			}
+		}
+		if(i >= sigs->nkey){
+			if(sigs->nkey >= nelem(sigs->keys))
+				error("too many keys");
+			sigs->keys[sigs->nkey++] = key;
+		}
+		poperror();
+		qunlock(&sigs->l);
+		poperror();	/* key */
+
+		return n;
+	case Qctl:
+		error(Ebadctl);
+		break;
+	}
+	return 0;
+}
+
+Dev signdevtab = {
+	0x03A3,	/* L'Σ',	/* U+03A3 */
+	"sign",
+
+	devinit,
+	signattach,
+	signwalk,
+	signstat,
+	signopen,
+	devcreate,
+	signclose,
+	signread,
+	devbread,
+	signwrite,
+	devbwrite,
+	devremove,
+	devwstat
+};