diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 5f9f7b0..122a17d 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -23,6 +23,11 @@
 #include "mbedtls/memory_buffer_alloc.h"
 #endif
 
+#if defined(MBEDTLS_CHECK_PARAMS)
+#include "mbedtls/platform_util.h"
+#include <setjmp.h>
+#endif
+
 #ifdef _MSC_VER
 #include <basetsd.h>
 typedef UINT8 uint8_t;
@@ -65,29 +70,50 @@
 #define DISPATCH_UNSUPPORTED_SUITE      -5  /* Test suite not supported by the
                                                build */
 
+typedef enum
+{
+    PARAMFAIL_TESTSTATE_IDLE = 0,           /* No parameter failure call test */
+    PARAMFAIL_TESTSTATE_PENDING,            /* Test call to the parameter failure
+                                             * is pending */
+    PARAMFAIL_TESTSTATE_CALLED              /* The test call to the parameter
+                                             * failure function has been made */
+} paramfail_test_state_t;
+
 
 /*----------------------------------------------------------------------------*/
 /* Macros */
 
-/** Evaluate an expression and fail the test case if it is false.
+/**
+ * \brief   This macro tests the expression passed to it as a test step or
+ *          individual test in a test case.
  *
- * Failing the test means:
- * - Mark this test case as failed.
- * - Print a message identifying the failure.
- * - Jump to the \c exit label.
+ *          It allows a library function to return a value and return an error
+ *          code that can be tested.
  *
- * This macro expands to an instruction, not an expression.
- * It may jump to the \c exit label.
+ *          When MBEDTLS_CHECK_PARAMS is enabled, calls to the parameter failure
+ *          callback, MBEDTLS_PARAM_FAILED(), will be assumed to be a test
+ *          failure.
  *
- * \param TEST      The expression to evaluate.
+ *          This macro is not suitable for negative parameter validation tests,
+ *          as it assumes the test step will not create an error.
+ *
+ *          Failing the test means:
+ *          - Mark this test case as failed.
+ *          - Print a message identifying the failure.
+ *          - Jump to the \c exit label.
+ *
+ *          This macro expands to an instruction, not an expression.
+ *          It may jump to the \c exit label.
+ *
+ * \param   TEST    The test expression to be tested.
  */
-#define TEST_ASSERT( TEST )                         \
-    do {                                            \
-        if( ! (TEST) )                              \
-        {                                           \
-            test_fail( #TEST, __LINE__, __FILE__ ); \
-            goto exit;                              \
-        }                                           \
+#define TEST_ASSERT( TEST )                                 \
+    do {                                                    \
+       if( ! (TEST) )                                       \
+       {                                                    \
+          test_fail( #TEST, __LINE__, __FILE__ );           \
+          goto exit;                                        \
+       }                                                    \
     } while( 0 )
 
 /** Evaluate two expressions and fail the test case if they have different
@@ -161,6 +187,105 @@
     }                                                                   \
     while( 0 )
 
+#if defined(MBEDTLS_CHECK_PARAMS) && !defined(MBEDTLS_PARAM_FAILED_ALT)
+/**
+ * \brief   This macro tests the statement passed to it as a test step or
+ *          individual test in a test case. The macro assumes the test will fail
+ *          and will generate an error.
+ *
+ *          It allows a library function to return a value and tests the return
+ *          code on return to confirm the given error code was returned.
+ *
+ *          When MBEDTLS_CHECK_PARAMS is enabled, calls to the parameter failure
+ *          callback, MBEDTLS_PARAM_FAILED(), are assumed to indicate the
+ *          expected failure, and the test will pass.
+ *
+ *          This macro is intended for negative parameter validation tests,
+ *          where the failing function may return an error value or call
+ *          MBEDTLS_PARAM_FAILED() to indicate the error.
+ *
+ * \param   PARAM_ERROR_VALUE   The expected error code.
+ *
+ * \param   TEST                The test expression to be tested.
+ */
+#define TEST_INVALID_PARAM_RET( PARAM_ERR_VALUE, TEST )                     \
+    do {                                                                    \
+        test_info.paramfail_test_state = PARAMFAIL_TESTSTATE_PENDING;       \
+        if( (TEST) != (PARAM_ERR_VALUE) ||                                  \
+            test_info.paramfail_test_state != PARAMFAIL_TESTSTATE_CALLED )  \
+        {                                                                   \
+            test_fail( #TEST, __LINE__, __FILE__ );                         \
+            goto exit;                                                      \
+        }                                                                   \
+   } while( 0 )
+
+/**
+ * \brief   This macro tests the statement passed to it as a test step or
+ *          individual test in a test case. The macro assumes the test will fail
+ *          and will generate an error.
+ *
+ *          It assumes the library function under test cannot return a value and
+ *          assumes errors can only be indicated byt calls to
+ *          MBEDTLS_PARAM_FAILED().
+ *
+ *          When MBEDTLS_CHECK_PARAMS is enabled, calls to the parameter failure
+ *          callback, MBEDTLS_PARAM_FAILED(), are assumed to indicate the
+ *          expected failure. If MBEDTLS_CHECK_PARAMS is not enabled, no test
+ *          can be made.
+ *
+ *          This macro is intended for negative parameter validation tests,
+ *          where the failing function can only return an error by calling
+ *          MBEDTLS_PARAM_FAILED() to indicate the error.
+ *
+ * \param   TEST                The test expression to be tested.
+ */
+#define TEST_INVALID_PARAM( TEST )                                          \
+    do {                                                                    \
+        memcpy(jmp_tmp, param_fail_jmp, sizeof(jmp_buf));                   \
+        if( setjmp( param_fail_jmp ) == 0 )                                 \
+        {                                                                   \
+            TEST;                                                           \
+            test_fail( #TEST, __LINE__, __FILE__ );                         \
+            goto exit;                                                      \
+        }                                                                   \
+        memcpy(param_fail_jmp, jmp_tmp, sizeof(jmp_buf));                   \
+    } while( 0 )
+#endif /* MBEDTLS_CHECK_PARAMS && !MBEDTLS_PARAM_FAILED_ALT */
+
+/**
+ * \brief   This macro tests the statement passed to it as a test step or
+ *          individual test in a test case. The macro assumes the test will not fail.
+ *
+ *          It assumes the library function under test cannot return a value and
+ *          assumes errors can only be indicated by calls to
+ *          MBEDTLS_PARAM_FAILED().
+ *
+ *          When MBEDTLS_CHECK_PARAMS is enabled, calls to the parameter failure
+ *          callback, MBEDTLS_PARAM_FAILED(), are assumed to indicate the
+ *          expected failure. If MBEDTLS_CHECK_PARAMS is not enabled, no test
+ *          can be made.
+ *
+ *          This macro is intended to test that functions returning void
+ *          accept all of the parameter values they're supposed to accept - eg
+ *          that they don't call MBEDTLS_PARAM_FAILED() when a parameter
+ *          that's allowed to be NULL happens to be NULL.
+ *
+ *          Note: for functions that return something other that void,
+ *          checking that they accept all the parameters they're supposed to
+ *          accept is best done by using TEST_ASSERT() and checking the return
+ *          value as well.
+ *
+ *          Note: this macro is available even when #MBEDTLS_CHECK_PARAMS is
+ *          disabled, as it makes sense to check that the functions accept all
+ *          legal values even if this option is disabled - only in that case,
+ *          the test is more about whether the function segfaults than about
+ *          whether it invokes MBEDTLS_PARAM_FAILED().
+ *
+ * \param   TEST                The test expression to be tested.
+ */
+#define TEST_VALID_PARAM( TEST )                                    \
+    TEST_ASSERT( ( TEST, 1 ) );
+
 #define assert(a) if( !( a ) )                                      \
 {                                                                   \
     mbedtls_fprintf( stderr, "Assertion Failed at %s:%d - %s\n",   \
@@ -247,9 +372,9 @@
 /*----------------------------------------------------------------------------*/
 /* Global variables */
 
-
 static struct
 {
+    paramfail_test_state_t paramfail_test_state;
     int failed;
     const char *test;
     const char *filename;
@@ -261,6 +386,11 @@
 mbedtls_platform_context platform_ctx;
 #endif
 
+#if defined(MBEDTLS_CHECK_PARAMS)
+jmp_buf param_fail_jmp;
+jmp_buf jmp_tmp;
+#endif
+
 /*----------------------------------------------------------------------------*/
 /* Helper flags for complex dependencies */
 
@@ -278,6 +408,15 @@
 
 /*----------------------------------------------------------------------------*/
 /* Helper Functions */
+
+static void test_fail( const char *test, int line_no, const char* filename )
+{
+    test_info.failed = 1;
+    test_info.test = test;
+    test_info.line_no = line_no;
+    test_info.filename = filename;
+}
+
 static int platform_setup()
 {
     int ret = 0;
@@ -294,6 +433,30 @@
 #endif /* MBEDTLS_PLATFORM_C */
 }
 
+#if defined(MBEDTLS_CHECK_PARAMS)
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line )
+{
+    /* If we are testing the callback function...  */
+    if( test_info.paramfail_test_state == PARAMFAIL_TESTSTATE_PENDING )
+    {
+        test_info.paramfail_test_state = PARAMFAIL_TESTSTATE_CALLED;
+    }
+    else
+    {
+        /* ...else we treat this as an error */
+
+        /* Record the location of the failure, but not as a failure yet, in case
+         * it was part of the test */
+        test_fail( failure_condition, line, file );
+        test_info.failed = 0;
+
+        longjmp( param_fail_jmp, 1 );
+    }
+}
+#endif
+
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
 static int redirect_output( FILE** out_stream, const char* path )
 {
@@ -310,6 +473,7 @@
 
     if( *out_stream == NULL )
     {
+        close( stdout_fd );
         return -1;
     }
 
@@ -582,25 +746,17 @@
     return( 0 );
 }
 
-static void test_fail( const char *test, int line_no, const char* filename )
-{
-    test_info.failed = 1;
-    test_info.test = test;
-    test_info.line_no = line_no;
-    test_info.filename = filename;
-}
-
 int hexcmp( uint8_t * a, uint8_t * b, uint32_t a_len, uint32_t b_len )
 {
     int ret = 0;
     uint32_t i = 0;
 
-    if ( a_len != b_len )
+    if( a_len != b_len )
         return( -1 );
 
     for( i = 0; i < a_len; i++ )
     {
-        if ( a[i] != b[i] )
+        if( a[i] != b[i] )
         {
             ret = -1;
             break;
@@ -608,4 +764,3 @@
     }
     return ret;
 }
-