Some small optimizations and better checking of tree accesses.

diff --git a/lib/decoding.c b/lib/decoding.c
index 4f21d24..c500417 100644 (file)
--- a/lib/decoding.c
+++ b/lib/decoding.c
@@ -728,8 +728,6 @@ _asn1_get_octet_string (const unsigned char *der, ASN1_TYPE node, int *len)
          asn1_length_der (tot_len, temp, &len2);
          _asn1_set_value (node, temp, len2);
 
-         tot_len += len2;
-
          ret = _asn1_extract_der_octet (node, der, *len);
          if (ret != ASN1_SUCCESS)
            return ret;
@@ -741,9 +739,10 @@ _asn1_get_octet_string (const unsigned char *der, ASN1_TYPE node, int *len)
       len2 = asn1_get_length_der (der, *len, &len3);
       if (len2 < 0)
        return ASN1_DER_ERROR;
-      if (node)
-       _asn1_set_value (node, der, len3 + len2);
+
       counter = len3 + len2;
+      if (node)
+       _asn1_set_value (node, der, counter);
     }
 
   *len = counter;
@@ -2248,6 +2247,9 @@ asn1_der_decoding_startEnd (ASN1_TYPE element, const void *ider, int len,
   p = node;
   while (1)
     {
+      if (p == NULL)
+        return ASN1_DER_ERROR;
+
       ris = ASN1_SUCCESS;
 
       if (move != UP)
@@ -2255,6 +2257,9 @@ asn1_der_decoding_startEnd (ASN1_TYPE element, const void *ider, int len,
          if (p->type & CONST_SET)
            {
              p2 = _asn1_find_up (p);
+              if (p2 == NULL)
+                return ASN1_DER_ERROR;
+
              len2 = _asn1_strtol (p2->value, NULL, 10);
              if (len2 == -1)
                {
@@ -2274,7 +2279,9 @@ asn1_der_decoding_startEnd (ASN1_TYPE element, const void *ider, int len,
                }
              else if (counter > len2)
                return ASN1_DER_ERROR;
+
              p2 = p2->down;
+
              while (p2)
                {
                  if ((p2->type & CONST_SET) && (p2->type & CONST_NOT_USED))
@@ -2286,6 +2293,9 @@ asn1_der_decoding_startEnd (ASN1_TYPE element, const void *ider, int len,
                      else
                        {
                          p3 = p2->down;
+                          if (p3 == NULL)
+                            return ASN1_DER_ERROR;
+
                          ris =
                            _asn1_extract_tag_der (p3, der + counter,
                                                   len - counter, &len2);
@@ -2309,6 +2319,9 @@ asn1_der_decoding_startEnd (ASN1_TYPE element, const void *ider, int len,
          if (type_field (p->type) == TYPE_CHOICE)
            {
              p = p->down;
+              if (p == NULL)
+                return ASN1_DER_ERROR;
+
              ris =
                _asn1_extract_tag_der (p, der + counter, len - counter,
                                       &len2);