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authorGuy Harris <guy@alum.mit.edu>2003-05-10 02:00:41 +0000
committerGuy Harris <guy@alum.mit.edu>2003-05-10 02:00:41 +0000
commit57958693a135ae83cf2127d3032fc6bfc0ec3f1c (patch)
tree9b5c3d97dd3f0241bb39bdb54de44c4e26dd8e0e /asn1.c
parent01e6542ed54102c60310bdf84c7da690c4f5f6d6 (diff)
Expand some comments.
Do the "tvb_ensure_bytes_exist()" check, and the check for a zero-length bit string, in the code to process a bit string. svn path=/trunk/; revision=7659
Diffstat (limited to 'asn1.c')
-rw-r--r--asn1.c40
1 files changed, 32 insertions, 8 deletions
diff --git a/asn1.c b/asn1.c
index 1202eabd0f..709b070a78 100644
--- a/asn1.c
+++ b/asn1.c
@@ -1,7 +1,7 @@
/* asn1.c
* Routines for ASN.1 BER dissection
*
- * $Id: asn1.c,v 1.18 2003/04/28 00:31:26 guy Exp $
+ * $Id: asn1.c,v 1.19 2003/05/10 02:00:41 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
@@ -607,20 +607,42 @@ asn1_bits_decode ( ASN1_SCK *asn1, int enc_len, guchar **bits,
int eoc;
guchar *ptr;
- eoc = asn1->offset + enc_len;
*bits = NULL;
ret = asn1_octet_decode (asn1, unused);
if (ret != ASN1_ERR_NOERROR)
return ret;
*len = 0;
- ptr = *bits = g_malloc(enc_len);
+
+ /*
+ * First, make sure the entire string is in the tvbuff, and throw
+ * an exception if it isn't. If the length is bogus, this should
+ * keep us from trying to allocate an immensely large buffer.
+ * (It won't help if the length is *valid* but immensely large,
+ * but that's another matter; in any case, that would happen only
+ * if we had an immensely large tvbuff....)
+ */
+ if (enc_len != 0) {
+ tvb_ensure_bytes_exist(asn1->tvb, asn1->offset, enc_len);
+ *bits = g_malloc (enc_len);
+ } else {
+ /*
+ * If the length is 0, we allocate a 1-byte buffer, as
+ * "g_malloc()" returns NULL if passed 0 as an argument,
+ * and our caller expects us to return a pointer to a
+ * buffer.
+ */
+ *bits = g_malloc (1);
+ }
+
+ eoc = asn1->offset + enc_len;
+ ptr = *bits;
while (asn1->offset < eoc) {
ret = asn1_octet_decode (asn1, (guchar *)ptr++);
if (ret != ASN1_ERR_NOERROR) {
g_free(*bits);
*bits = NULL;
return ret;
- }
+ }
}
*len = ptr - *bits;
return ASN1_ERR_NOERROR;
@@ -654,10 +676,11 @@ asn1_string_value_decode ( ASN1_SCK *asn1, int enc_len, guchar **octets)
* an exception if it isn't. If the length is bogus, this should
* keep us from trying to allocate an immensely large buffer.
* (It won't help if the length is *valid* but immensely large,
- * but that's another matter.)
+ * but that's another matter; in any case, that would happen only
+ * if we had an immensely large tvbuff....)
*/
if (enc_len != 0) {
- tvb_ensure_bytes_exist(asn1->tvb, asn1->offset, enc_len);
+ tvb_ensure_bytes_exist(asn1->tvb, asn1->offset, enc_len);
*octets = g_malloc (enc_len);
} else {
/*
@@ -821,10 +844,11 @@ asn1_oid_value_decode ( ASN1_SCK *asn1, int enc_len, subid_t **oid, guint *len)
* an exception if it isn't. If the length is bogus, this should
* keep us from trying to allocate an immensely large buffer.
* (It won't help if the length is *valid* but immensely large,
- * but that's another matter.)
+ * but that's another matter; in any case, that would happen only
+ * if we had an immensely large tvbuff....)
*/
if (enc_len != 0)
- tvb_ensure_bytes_exist(asn1->tvb, asn1->offset, enc_len);
+ tvb_ensure_bytes_exist(asn1->tvb, asn1->offset, enc_len);
eoc = asn1->offset + enc_len;