simplified and optimized asn1_der_decoding_startEnd().

The second pass decoding is now avoided as the start and end
values are cached during decoding.

2 files changed, 32 insertions, 372 deletions

diff --git a/lib/decoding.c b/lib/decoding.c
index 47af7cd..510bb67 100644
--- a/lib/decoding.c
+++ b/lib/decoding.c
@@ -900,7 +900,7 @@ asn1_der_decoding (asn1_node * element, const void *ider, int ider_len,
   int counter, len2, len3, len4, move, ris, tlen;
   unsigned char class;
   unsigned long tag;
-  int indefinite, result;
+  int indefinite, result, total_len = ider_len;
   const unsigned char *der = ider;
 
   node = *element;
@@ -978,6 +978,10 @@ asn1_der_decoding (asn1_node * element, const void *ider, int ider_len,
 		}
 	    }
 
+	  /* the position in the DER structure this starts */
+	  p->start = counter;
+	  p->end = total_len;
+
 	  if ((p->type & CONST_OPTION) || (p->type & CONST_DEFAULT))
 	    {
 	      p2 = _asn1_find_up (p);
@@ -1037,6 +1041,8 @@ asn1_der_decoding (asn1_node * element, const void *ider, int ider_len,
 		}
 	      else if (type_field (p->type) != ASN1_ETYPE_CHOICE)
 		p = p->down;
+
+	      p->start = counter;
 	    }
 
 	  if ((p->type & CONST_OPTION) || (p->type & CONST_DEFAULT))
@@ -1433,6 +1439,11 @@ asn1_der_decoding (asn1_node * element, const void *ider, int ider_len,
 	    }
 	}
 
+      if (p)
+        {
+      	  p->end = counter - 1;
+        }
+
       if (p == node && move != DOWN)
 	break;
 
@@ -1535,12 +1546,8 @@ int
 asn1_der_decoding_startEnd (asn1_node element, const void *ider, int ider_len,
 			    const char *name_element, int *start, int *end)
 {
-  asn1_node node, node_to_find, p, p2;
-  int counter, len2, len3, len4, move, ris;
-  unsigned char class;
-  unsigned long tag;
-  int indefinite, result = ASN1_DER_ERROR;
-  const unsigned char *der = ider;
+  asn1_node node, node_to_find;
+  int result = ASN1_DER_ERROR;
 
   node = element;
 
@@ -1552,377 +1559,28 @@ asn1_der_decoding_startEnd (asn1_node element, const void *ider, int ider_len,
   if (node_to_find == NULL)
     return ASN1_ELEMENT_NOT_FOUND;
 
-  if (node_to_find == node)
-    {
-      *start = 0;
-      *end = ider_len - 1;
-      return ASN1_SUCCESS;
-    }
+  *start = node_to_find->start;
+  *end = node_to_find->end;
 
-  if (node->type & CONST_OPTION)
-    return ASN1_GENERIC_ERROR;
-
-  counter = 0;
-  move = DOWN;
-  p = node;
-  while (1)
+  if (*start == 0 && *end == 0)
     {
-      if (p == NULL)
-	return ASN1_DER_ERROR;
-
-      ris = ASN1_SUCCESS;
-
-      if (move != UP)
-	{
-	  if (p->type & CONST_SET)
-	    {
-	      p2 = _asn1_find_up (p);
-	      if (p2 == NULL)
-	        {
-		  warn();
-		  return ASN1_DER_ERROR;
-		}
-
-	      len2 = p2->tmp_ival;
-	      if (len2 == -1)
-		{
-		  if (HAVE_TWO(ider_len) && !der[counter] && !der[counter + 1])
-		    {
-		      p = p2;
-		      move = UP;
-		      counter += 2;
-		      DECR_LEN(ider_len, 2);
-		      continue;
-		    }
-		}
-	      else if (counter == len2)
-		{
-		  p = p2;
-		  move = UP;
-		  continue;
-		}
-	      else if (counter > len2)
-	        {
-		  warn();
-		  return ASN1_DER_ERROR;
-		}
-
-	      p2 = p2->down;
-
-	      while (p2)
-		{
-		  if ((p2->type & CONST_SET) && (p2->type & CONST_NOT_USED))
-		    {		/* CONTROLLARE */
-		      ris =
-			  extract_tag_der_recursive (p2, der + counter,
-						 ider_len, &len2);
-		      if (ris == ASN1_SUCCESS)
-			{
-			  p2->type &= ~CONST_NOT_USED;
-			  p = p2;
-			  break;
-			}
-		    }
-		  p2 = p2->right;
-		}
-	      if (p2 == NULL)
-	        {
-		  warn();
-		  return ASN1_DER_ERROR;
-		}
-	    }
-
-	  if (p == node_to_find)
-	    *start = counter;
-
-	  if (type_field (p->type) == ASN1_ETYPE_CHOICE)
-	    {
-	      p = p->down;
-	      if (p == NULL)
-	        {
-		  warn();
-		  return ASN1_DER_ERROR;
-		}
-
-	      ris =
-		_asn1_extract_tag_der (p, der + counter, ider_len,
-				       &len2);
-	      if (p == node_to_find)
-		*start = counter;
-	    }
-
-	  if (ris == ASN1_SUCCESS)
-	    ris =
-	      _asn1_extract_tag_der (p, der + counter, ider_len, &len2);
-	  if (ris != ASN1_SUCCESS)
-	    {
-	      if (p->type & CONST_OPTION)
-		{
-		  p->type |= CONST_NOT_USED;
-		  move = RIGHT;
-		}
-	      else if (p->type & CONST_DEFAULT)
-		{
-		  move = RIGHT;
-		}
-	      else
-		{
-		  warn();
-		  return ASN1_TAG_ERROR;
-		}
-	    }
-	  else
-	    {
-	      DECR_LEN(ider_len, len2);
-	      counter += len2;
-	    }
-	}
-
-      if (ris == ASN1_SUCCESS)
-	{
-	  switch (type_field (p->type))
-	    {
-	    case ASN1_ETYPE_NULL:
-	       DECR_LEN(ider_len, 1);
-
-	      if (der[counter])
-	        {
-		  warn();
-		  return ASN1_DER_ERROR;
-		}
-	      counter++;
-	      move = RIGHT;
-	      break;
-	    case ASN1_ETYPE_BOOLEAN:
-              DECR_LEN(ider_len, 2);
-
-	      if (der[counter] != 1)
-	        {
-		  warn();
-		  return ASN1_DER_ERROR;
-		}
-
-	      counter += 2;
-	      move = RIGHT;
-	      break;
-	    case ASN1_ETYPE_OCTET_STRING:
-	      ris = _asn1_get_octet_string (NULL, der + counter, ider_len, &len3);
-	      if (ris != ASN1_SUCCESS)
-	        {
-		  warn();
-		  return ris;
-		}
-              DECR_LEN(ider_len, len3);
-	      counter += len3;
-	      move = RIGHT;
-	      break;
-	    case ASN1_ETYPE_UTC_TIME:
-	    case ASN1_ETYPE_GENERALIZED_TIME:
-	    case ASN1_ETYPE_OBJECT_ID:
-	    case ASN1_ETYPE_INTEGER:
-	    case ASN1_ETYPE_ENUMERATED:
-	    case ASN1_ETYPE_GENERALSTRING:
-	    case ASN1_ETYPE_NUMERIC_STRING:
-	    case ASN1_ETYPE_IA5_STRING:
-	    case ASN1_ETYPE_TELETEX_STRING:
-	    case ASN1_ETYPE_PRINTABLE_STRING:
-	    case ASN1_ETYPE_UNIVERSAL_STRING:
-	    case ASN1_ETYPE_BMP_STRING:
-	    case ASN1_ETYPE_UTF8_STRING:
-	    case ASN1_ETYPE_VISIBLE_STRING:
-	    case ASN1_ETYPE_BIT_STRING:
-	      len2 =
-		asn1_get_length_der (der + counter, ider_len, &len3);
-	      if (len2 < 0)
-	        {
-		  warn();
-		  return ASN1_DER_ERROR;
-		}
-
-              DECR_LEN(ider_len, len3 + len2);
-	      counter += len3 + len2;
-	      move = RIGHT;
-	      break;
-	    case ASN1_ETYPE_SEQUENCE:
-	    case ASN1_ETYPE_SET:
-	      if (move != UP)
-		{
-		  len3 =
-		    asn1_get_length_der (der + counter, ider_len, &len2);
-		  if (len3 < -1)
-		    {
-  		      warn();
-		      return ASN1_DER_ERROR;
-		    }
-
-                  DECR_LEN(ider_len, len2);
-		  counter += len2;
-
-		  if (len3 == 0)
-		    move = RIGHT;
-		  else
-		    move = DOWN;
-		}
-	      else
-		{
-		  if (HAVE_TWO(ider_len) && !der[counter] && !der[counter + 1])	/* indefinite length method */
-		    {
-		      counter += 2;
-		      DECR_LEN(ider_len, 2);
-		    }
-		  move = RIGHT;
-		}
-	      break;
-	    case ASN1_ETYPE_SEQUENCE_OF:
-	    case ASN1_ETYPE_SET_OF:
-	      if (move != UP)
-		{
-		  len3 =
-		    asn1_get_length_der (der + counter, ider_len, &len2);
-		  if (len3 < -1)
-		    {
-  		      warn();
-		      return ASN1_DER_ERROR;
-		    }
-
-                  DECR_LEN(ider_len, len2);
-		  counter += len2;
-
-		  if (len3 == -1)
-		    {
-		       if (HAVE_TWO(ider_len) && !der[counter] && !der[counter + 1])
-		         {
-  		           DECR_LEN(ider_len, 2);
-		           counter += 2;
-		         }
-		    }
-
-		  if (len3)
-		    {
-		      p2 = p->down;
-		      while ((type_field (p2->type) == ASN1_ETYPE_TAG) ||
-			     (type_field (p2->type) == ASN1_ETYPE_SIZE))
-			p2 = p2->right;
-		      p = p2;
-		    }
-		}
-	      else
-		{
-		  if (HAVE_TWO(ider_len) && !der[counter] && !der[counter + 1])	/* indefinite length method */
-		    {
-		      DECR_LEN(ider_len, 2);
-		      counter += 2;
-		    }
-		}
-	      move = RIGHT;
-	      break;
-	    case ASN1_ETYPE_ANY:
-	      if (asn1_get_tag_der
-		  (der + counter, ider_len, &class, &len2,
-		   &tag) != ASN1_SUCCESS)
-		 {
-  		    warn();
-		    return ASN1_DER_ERROR;
-		 }
-
-	      DECR_LEN(ider_len, len2);
-
-	      len4 =
-		asn1_get_length_der (der + counter + len2,
-				     ider_len, &len3);
-	      if (len4 < -1)
-	        {
- 	          warn();
-		  return ASN1_DER_ERROR;
-		}
-
-	      if (len4 != -1)
-		{
-		  DECR_LEN(ider_len, len3 + len4);
-		  counter += len2 + len3 + len4;
-		}
-	      else
-		{		/* indefinite length */
-		  /* Check indefinite lenth method in an EXPLICIT TAG */
-		  ider_len += len2; /* undo DECR_LEN */
-
-		  if (counter == 0)
-		    {
-		      result = ASN1_DER_ERROR;
-                      warn();
-		      goto cleanup;
-		    }
-
-		  if ((p->type & CONST_TAG) && (der[counter - 1] == 0x80))
-		    indefinite = 1;
-		  else
-		    indefinite = 0;
-
-		  ris =
-		    _asn1_get_indefinite_length_string (der + counter, ider_len, &len2);
-		  if (ris != ASN1_SUCCESS)
-		    {
- 	              warn();
-		      return ris;
-		    }
-		  counter += len2;
-		  DECR_LEN(ider_len, len2);
-
-		  /* Check if a couple of 0x00 are present due to an EXPLICIT TAG with
-		     an indefinite length method. */
-		  if (indefinite)
-		    {
-		      DECR_LEN(ider_len, 2);
-
-		      if (!der[counter] && !der[counter + 1])
-			counter += 2;
-		      else
-		        {
- 	                  warn();
-			  return ASN1_DER_ERROR;
-			}
-		    }
-		}
-	      move = RIGHT;
-	      break;
-	    default:
-	      move = (move == UP) ? RIGHT : DOWN;
-	      break;
-	    }
-	}
+      /* it seems asn1_der_decoding() wasn't called before. Do it now */
+      result = asn1_der_decoding (&node, ider, ider_len, NULL);
+      if (result != ASN1_SUCCESS)
+        {
+          warn();
+          return result;
+        }
 
-      if ((p == node_to_find) && (move == RIGHT))
-	{
-	  *end = counter - 1;
-	  return ASN1_SUCCESS;
-	}
+      node_to_find = asn1_find_node (node, name_element);
+      if (node_to_find == NULL)
+        return ASN1_ELEMENT_NOT_FOUND;
 
-      if (p == node && move != DOWN)
-	break;
-
-      if (move == DOWN)
-	{
-	  if (p->down)
-	    p = p->down;
-	  else
-	    move = RIGHT;
-	}
-      if ((move == RIGHT) && !(p->type & CONST_SET))
-	{
-	  if (p->right)
-	    p = p->right;
-	  else
-	    move = UP;
-	}
-      if (move == UP)
-	p = _asn1_find_up (p);
+      *start = node_to_find->start;
+      *end = node_to_find->end;
     }
 
-  warn();
-  return ASN1_ELEMENT_NOT_FOUND;
-
-cleanup:
-  return result;
+  return ASN1_SUCCESS;
 }
 
 /**
diff --git a/lib/int.h b/lib/int.h
index ab35e5b..82d0d3f 100644
--- a/lib/int.h
+++ b/lib/int.h
@@ -59,6 +59,8 @@ struct asn1_node_st
 
   /* values used during decoding/coding */
   int tmp_ival;
+  unsigned start; /* the start of the DER sequence - if decoded */
+  unsigned end; /* the end of the DER sequence - if decoded */
 };
 
 typedef struct tag_and_class_st