Add buffer length tests for mbedtls_asn1_write_len()
diff --git a/tests/suites/test_suite_asn1write.function b/tests/suites/test_suite_asn1write.function
index 160190f..ba4db88 100644
--- a/tests/suites/test_suite_asn1write.function
+++ b/tests/suites/test_suite_asn1write.function
@@ -84,7 +84,8 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
-void mbedtls_asn1_write_len( int len, char *check_str, int result )
+void mbedtls_asn1_write_len( int len, char *check_str, int buf_len,
+                             int result )
 {
     int ret;
     unsigned char buf[150];
@@ -96,7 +97,7 @@
     memset( asn1, 0, sizeof( asn1 ) );
     asn1_len = unhexify( asn1, check_str );
 
-    p = buf + GUARD_LEN + asn1_len;
+    p = buf + GUARD_LEN + buf_len;
 
     ret = mbedtls_asn1_write_len( &p, buf + GUARD_LEN, (size_t) len );
 
@@ -106,13 +107,13 @@
     for( i = 0; i < GUARD_LEN; i++ )
     {
         TEST_ASSERT( buf[i] == GUARD_VAL );
-        TEST_ASSERT( buf[GUARD_LEN + asn1_len + i] == GUARD_VAL );
+        TEST_ASSERT( buf[GUARD_LEN + buf_len + i] == GUARD_VAL );
     }
 
     if( result >= 0 )
     {
         TEST_ASSERT( (size_t) ret == asn1_len );
-        TEST_ASSERT( p + asn1_len == buf + GUARD_LEN + asn1_len );
+        TEST_ASSERT( p + asn1_len == buf + GUARD_LEN + buf_len );
 
         TEST_ASSERT( memcmp( p, asn1, asn1_len ) == 0 );
     }