ref: 5e24adafef9c41bf3c62d7e258819bd3b21afb34
parent: 4cf801b8537276103a09d44dad31f637164916e7
author: cinap_lenrek <[email protected]>
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;
}