Renamed asn1_der_decoding_relaxed(), added ASN1_DECODE_FLAG_ALLOW_PADDING.

3 files changed, 18 insertions, 24 deletions

diff --git a/lib/decoding.c b/lib/decoding.c
index 243af0d..b7e49b4 100644
--- a/lib/decoding.c
+++ b/lib/decoding.c
@@ -872,26 +872,31 @@ static void delete_unneeded_choice_fields(asn1_node p)
 
 
 /**
- * asn1_der_decoding_relaxed
+ * asn1_der_decoding2
  * @element: pointer to an ASN1 structure.
  * @ider: vector that contains the DER encoding.
  * @max_ider_len: pointer to an integer giving the information about the
  *   maximal number of bytes occupied by *@ider. The real size of the DER
  *   encoding is returned through this pointer.
+ * @flags: flags controlling the behaviour of the function.
  * @errorDescription: null-terminated string contains details when an
  *   error occurred.
  *
  * Fill the structure *@element with values of a DER encoding string. The
  * structure must just be created with function asn1_create_element().
  *
+ * If %ASN1_DECODE_FLAG_ALLOW_PADDING flag is set then the function will ignore
+ * padding after the decoded DER data. Upon a successful return the value of
+ * *@max_ider_len will be set to the number of bytes decoded.
+ *
  * Returns: %ASN1_SUCCESS if DER encoding OK, %ASN1_ELEMENT_NOT_FOUND
  *   if @ELEMENT is %NULL, and %ASN1_TAG_ERROR or
  *   %ASN1_DER_ERROR if the der encoding doesn't match the structure
  *   name (*@ELEMENT deleted).
  **/
 int
-asn1_der_decoding_relaxed (asn1_node * element, const void *ider,
-			   int *max_ider_len, char *errorDescription)
+asn1_der_decoding2 (asn1_node *element, const void *ider, int *max_ider_len,
+		    unsigned int flags, char *errorDescription)
 {
   asn1_node node, p, p2, p3;
   char temp[128];
@@ -1465,7 +1470,8 @@ asn1_der_decoding_relaxed (asn1_node * element, const void *ider,
 
   _asn1_delete_not_used (*element);
 
-  if (ider_len < 0)
+  if ((ider_len < 0) ||
+      (!(flags & ASN1_DECODE_FLAG_ALLOW_PADDING) && (ider_len != 0)))
     {
       warn();
       result = ASN1_DER_ERROR;
@@ -1506,23 +1512,7 @@ int
 asn1_der_decoding (asn1_node * element, const void *ider, int ider_len,
 		   char *errorDescription)
 {
-  int ider_read_len = ider_len;
-  int result;
-
-  result = asn1_der_decoding_relaxed (element, ider, &ider_read_len,
-				      errorDescription);
-  if ((result == ASN1_SUCCESS) && (ider_read_len != ider_len))
-    {
-      asn1_delete_structure (element);
-      /* Generate error description? */
-      result = ASN1_DER_ERROR;
-    }
-
-  return result;
-
-cleanup:
-  asn1_delete_structure (element);
-  return result;
+  return asn1_der_decoding2 (element, ider, &ider_len, 0, errorDescription);
 }
 
 #define FOUND        1
diff --git a/lib/libtasn1.h b/lib/libtasn1.h
index 4c71849..1e90b73 100644
--- a/lib/libtasn1.h
+++ b/lib/libtasn1.h
@@ -184,6 +184,9 @@ extern "C"
 /* makes sure the values are zeroized prior to deinitialization */
 #define ASN1_DELETE_FLAG_ZEROIZE 1
 
+/* Flags used by asn1_der_decoding2(). */
+#define ASN1_DECODE_FLAG_ALLOW_PADDING 1
+
 
   struct asn1_data_node_st
   {
@@ -259,8 +262,9 @@ extern "C"
 		     void *ider, int *len, char *ErrorDescription);
 
   extern ASN1_API int
-    asn1_der_decoding_relaxed (asn1_node * element, const void *ider,
-			       int *max_ider_len, char *errorDescription);
+    asn1_der_decoding2 (asn1_node *element, const void *ider,
+			int *max_ider_len, unsigned int flags,
+			char *errorDescription);
 
   extern ASN1_API int
     asn1_der_decoding (asn1_node * element, const void *ider,
diff --git a/lib/libtasn1.map b/lib/libtasn1.map
index 6d2f823..6424219 100644
--- a/lib/libtasn1.map
+++ b/lib/libtasn1.map
@@ -26,7 +26,7 @@ LIBTASN1_0_3
     asn1_delete_element;
     asn1_delete_structure;
     asn1_der_coding;
-    asn1_der_decoding_relaxed;
+    asn1_der_decoding2;
     asn1_der_decoding;
     asn1_der_decoding_element;
     asn1_der_decoding_startEnd;