use DECR_LEN in _asn1_get_octet_string()

diff --git a/lib/decoding.c b/lib/decoding.c
index a6ed982..f17686b 100644 (file)
--- a/lib/decoding.c
+++ b/lib/decoding.c
@@ -710,6 +710,7 @@ static int
 _asn1_get_octet_string (asn1_node node, const unsigned char *der, unsigned der_len, int *len)
 {
   int len2, len3, counter, tot_len, indefinite;
+  int result;
 
   counter = 0;
 
@@ -721,6 +722,8 @@ _asn1_get_octet_string (asn1_node node, const unsigned char *der, unsigned der_l
        return ASN1_DER_ERROR;
 
       counter += len3;
+      DECR_LEN(der_len, len3);
+
       if (indefinite >= 0)
        indefinite += len3;
 
@@ -731,25 +734,29 @@ _asn1_get_octet_string (asn1_node node, const unsigned char *der, unsigned der_l
 
          if (indefinite == -1)
            {
-             if ((der[counter] == 0) && (der[counter + 1] == 0))
+             if (HAVE_TWO(der_len) && (der[counter] == 0) && (der[counter + 1] == 0))
                {
                  counter += 2;
+                 DECR_LEN(der_len, 2);
                  break;
                }
            }
          else if (counter >= indefinite)
            break;
 
+          DECR_LEN(der_len, 1);
          if (der[counter] != ASN1_TAG_OCTET_STRING)
            return ASN1_DER_ERROR;
 
          counter++;
 
-         len2 = asn1_get_length_der (der + counter, der_len - counter, &len3);
+         len2 = asn1_get_length_der (der + counter, der_len, &len3);
          if (len2 <= 0)
            return ASN1_DER_ERROR;
 
+          DECR_LEN(der_len, len3 + len2);
          counter += len3 + len2;
+
          tot_len += len2;
        }
 
@@ -776,6 +783,7 @@ _asn1_get_octet_string (asn1_node node, const unsigned char *der, unsigned der_l
       if (len2 < 0)
        return ASN1_DER_ERROR;
 
+      DECR_LEN(der_len, len3+len2);
       counter = len3 + len2;
       if (node)
        _asn1_set_value (node, der, counter);
@@ -784,6 +792,8 @@ _asn1_get_octet_string (asn1_node node, const unsigned char *der, unsigned der_l
   *len = counter;
   return ASN1_SUCCESS;
 
+cleanup:
+  return result;
 }
 
 static int