shithub: riscv

Download patch

ref: 5e24adafef9c41bf3c62d7e258819bd3b21afb34
parent: 4cf801b8537276103a09d44dad31f637164916e7
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Wed Jan 6 00:30:44 EST 2016 

libsec: make sure theres no garbage after the asn.1 decode, cleanup


--- a/sys/src/libsec/port/x509.c
+++ b/sys/src/libsec/port/x509.c
@@ -130,8 +130,6 @@
 static int	is_string(Elem* pe, char** pstring);
 static int	is_time(Elem* pe, char** ptime);
 static int	decode(uchar* a, int alen, Elem* pelem);
-static int	decode_seq(uchar* a, int alen, Elist** pelist);
-static int	decode_value(uchar* a, int alen, int kind, int isconstr, Value* pval);
 static int	encode(Elem e, Bytes** pbytes);
 static int	oid_lookup(Ints* o, Ints** tab);
 static void	freevalfields(Value* v);
@@ -194,40 +192,15 @@
 decode(uchar* a, int alen, Elem* pelem)
 {
 	uchar* p = a;
+	int err;
 
-	return  ber_decode(&p, &a[alen], pelem);
+	err = ber_decode(&p, &a[alen], pelem);
+	if(err == ASN_OK && p != &a[alen])
+		err = ASN_EVALLEN;
+	return err;
 }
 
 /*
- * Like decode, but continue decoding after first element
- * of array ends.
- */
-static int
-decode_seq(uchar* a, int alen, Elist** pelist)
-{
-	uchar* p = a;
-
-	return seq_decode(&p, &a[alen], -1, 1, pelist);
-}
-
-/*
- * Decode the whole array as a BER encoding of an ASN1 value,
- * (i.e., the part after the tag and length).
- * Assume the value is encoded as universal tag "kind".
- * The constr arg is 1 if the value is constructed, 0 if primitive.
- * If there's an error, the return string will contain the error.
- * Depending on the error, the returned value may or may not
- * be nil.
- */
-static int
-decode_value(uchar* a, int alen, int kind, int isconstr, Value* pval)
-{
-	uchar* p = a;
-
-	return value_decode(&p, &a[alen], alen, kind, isconstr, pval);
-}
-
-/*
  * All of the following decoding routines take arguments:
  *	uchar **pp;
  *	uchar *pend;
@@ -2025,12 +1998,9 @@
 		goto errret;
 	if(!is_seq(&e, &el) || elistlen(el) != 6)
 		goto errret;
-version = -1;
+	version = -1;
 	if(!is_int(&el->hd, &version) || version != 0)
-{
-fprint(2, "version %d\n", version);
 		goto errret;
-}
 
 	el = el->tl;
 	key->pub.p = mp = asn1mpint(&el->hd);
@@ -2212,8 +2182,8 @@
 	el = nil;
 	memset(&e, 0, sizeof(e));
 	buflen = pkcs1decryptsignature(sig, siglen, pk, &buf);
-	if(buflen < 0 || decode(buf, buflen, &e) != ASN_OK || !is_seq(&e, &el) || elistlen(el) != 2 ||
-			!is_octetstring(&el->tl->hd, &digest)) {
+	if(buflen < 0 || decode(buf, buflen, &e) != ASN_OK
+	|| !is_seq(&e, &el) || elistlen(el) != 2 || !is_octetstring(&el->tl->hd, &digest)) {
 		err = "signature parse error";
 		goto end;
 	}