diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index dc76443..5200554 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -428,7 +428,8 @@
     const mbedtls_cipher_context_t *ctx )
 {
     MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
-    MBEDTLS_INTERNAL_VALIDATE_RET( ctx->cipher_info != NULL, 0 );
+    if( ctx->cipher_info == NULL )
+        return 0;
 
     return ctx->cipher_info->block_size;
 }
@@ -446,7 +447,8 @@
     const mbedtls_cipher_context_t *ctx )
 {
     MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, MBEDTLS_MODE_NONE );
-    MBEDTLS_INTERNAL_VALIDATE_RET( ctx->cipher_info != NULL, MBEDTLS_MODE_NONE );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_MODE_NONE;
 
     return ctx->cipher_info->mode;
 }
@@ -465,7 +467,8 @@
     const mbedtls_cipher_context_t *ctx )
 {
     MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
-    MBEDTLS_INTERNAL_VALIDATE_RET( ctx->cipher_info != NULL, 0 );
+    if( ctx->cipher_info == NULL )
+        return 0;
 
     if( ctx->iv_size != 0 )
         return (int) ctx->iv_size;
@@ -486,8 +489,8 @@
 {
     MBEDTLS_INTERNAL_VALIDATE_RET(
         ctx != NULL, MBEDTLS_CIPHER_NONE );
-    MBEDTLS_INTERNAL_VALIDATE_RET(
-        ctx->cipher_info != NULL, MBEDTLS_CIPHER_NONE );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_CIPHER_NONE;
 
     return ctx->cipher_info->type;
 }
@@ -505,7 +508,8 @@
     const mbedtls_cipher_context_t *ctx )
 {
     MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
-    MBEDTLS_INTERNAL_VALIDATE_RET( ctx->cipher_info != NULL, 0 );
+    if( ctx->cipher_info == NULL )
+        return 0;
 
     return ctx->cipher_info->name;
 }
@@ -524,8 +528,8 @@
 {
     MBEDTLS_INTERNAL_VALIDATE_RET(
         ctx != NULL, MBEDTLS_KEY_LENGTH_NONE );
-    MBEDTLS_INTERNAL_VALIDATE_RET(
-        ctx->cipher_info != NULL, MBEDTLS_KEY_LENGTH_NONE );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_KEY_LENGTH_NONE;
 
     return (int) ctx->cipher_info->key_bitlen;
 }
@@ -543,8 +547,8 @@
 {
     MBEDTLS_INTERNAL_VALIDATE_RET(
         ctx != NULL, MBEDTLS_OPERATION_NONE );
-    MBEDTLS_INTERNAL_VALIDATE_RET(
-        ctx->cipher_info != NULL, MBEDTLS_OPERATION_NONE );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_OPERATION_NONE;
 
     return ctx->operation;
 }
diff --git a/library/cipher.c b/library/cipher.c
index 14ff371..b37fc76 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -182,7 +182,8 @@
 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx, const mbedtls_cipher_info_t *cipher_info )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( cipher_info != NULL );
+    if( cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
 
@@ -211,10 +212,11 @@
                            const mbedtls_operation_t operation )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( key != NULL );
     CIPHER_VALIDATE_RET( operation == MBEDTLS_ENCRYPT ||
                          operation == MBEDTLS_DECRYPT );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     if( ( ctx->cipher_info->flags & MBEDTLS_CIPHER_VARIABLE_KEY_LEN ) == 0 &&
         (int) ctx->cipher_info->key_bitlen != key_bitlen )
@@ -251,8 +253,9 @@
     size_t actual_iv_size;
 
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     /* avoid buffer overflow in ctx->iv */
     if( iv_len > MBEDTLS_MAX_IV_LENGTH )
@@ -293,7 +296,8 @@
 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     ctx->unprocessed_len = 0;
 
@@ -305,8 +309,9 @@
                       const unsigned char *ad, size_t ad_len )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
 #if defined(MBEDTLS_GCM_C)
     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
@@ -348,10 +353,11 @@
     size_t block_size;
 
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
     CIPHER_VALIDATE_RET( output != NULL );
     CIPHER_VALIDATE_RET( olen != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     *olen = 0;
     block_size = mbedtls_cipher_get_block_size( ctx );
@@ -757,9 +763,10 @@
                    unsigned char *output, size_t *olen )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( output != NULL );
     CIPHER_VALIDATE_RET( olen != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     *olen = 0;
 
@@ -847,7 +854,8 @@
                                      mbedtls_cipher_padding_t mode )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     if( MBEDTLS_MODE_CBC != ctx->cipher_info->mode )
     {
@@ -898,8 +906,9 @@
                       unsigned char *tag, size_t tag_len )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     if( MBEDTLS_ENCRYPT != ctx->operation )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
@@ -931,8 +940,9 @@
     int ret;
 
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     if( MBEDTLS_DECRYPT != ctx->operation )
     {
@@ -997,11 +1007,12 @@
     size_t finish_olen;
 
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( iv_len == 0 || iv != NULL );
     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
     CIPHER_VALIDATE_RET( output != NULL );
     CIPHER_VALIDATE_RET( olen != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
     if( ( ret = mbedtls_cipher_set_iv( ctx, iv, iv_len ) ) != 0 )
         return( ret );
@@ -1032,13 +1043,14 @@
                          unsigned char *tag, size_t tag_len )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( iv != NULL );
     CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
     CIPHER_VALIDATE_RET( output != NULL );
     CIPHER_VALIDATE_RET( olen != NULL );
     CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
 #if defined(MBEDTLS_GCM_C)
     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
@@ -1088,13 +1100,14 @@
                          const unsigned char *tag, size_t tag_len )
 {
     CIPHER_VALIDATE_RET( ctx != NULL );
-    CIPHER_VALIDATE_RET( ctx->cipher_info != NULL );
     CIPHER_VALIDATE_RET( iv != NULL );
     CIPHER_VALIDATE_RET( ad_len == 0 || ad != NULL );
     CIPHER_VALIDATE_RET( ilen == 0 || input != NULL );
     CIPHER_VALIDATE_RET( output != NULL );
     CIPHER_VALIDATE_RET( olen != NULL );
     CIPHER_VALIDATE_RET( tag_len == 0 || tag != NULL );
+    if( ctx->cipher_info == NULL )
+        return MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA;
 
 #if defined(MBEDTLS_GCM_C)
     if( MBEDTLS_MODE_GCM == ctx->cipher_info->mode )
diff --git a/tests/suites/test_suite_cipher.function b/tests/suites/test_suite_cipher.function
index fba32fd..16327c3 100644
--- a/tests/suites/test_suite_cipher.function
+++ b/tests/suites/test_suite_cipher.function
@@ -48,53 +48,49 @@
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_setup( NULL, valid_info ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
-        mbedtls_cipher_setup( &valid_ctx, NULL ) );
+    TEST_ASSERT( mbedtls_cipher_setup( &valid_ctx, NULL ) ==
+                 MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
     /* mbedtls_cipher_get_block_size() */
     TEST_INVALID_PARAM_RET( 0, mbedtls_cipher_get_block_size( NULL ) );
-    TEST_INVALID_PARAM_RET( 0, mbedtls_cipher_get_block_size( &invalid_ctx ) );
+    TEST_ASSERT( mbedtls_cipher_get_block_size( &invalid_ctx ) == 0 );
 
     /* mbedtls_cipher_get_cipher_mode() */
     TEST_INVALID_PARAM_RET(
         MBEDTLS_MODE_NONE,
         mbedtls_cipher_get_cipher_mode( NULL ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_MODE_NONE,
-        mbedtls_cipher_get_cipher_mode( &invalid_ctx ) );
+    TEST_ASSERT( mbedtls_cipher_get_cipher_mode( &invalid_ctx ) ==
+                 MBEDTLS_MODE_NONE );
 
     /* mbedtls_cipher_get_iv_size() */
     TEST_INVALID_PARAM_RET( 0, mbedtls_cipher_get_iv_size( NULL ) );
-    TEST_INVALID_PARAM_RET( 0, mbedtls_cipher_get_iv_size( &invalid_ctx ) );
+    TEST_ASSERT( mbedtls_cipher_get_iv_size( &invalid_ctx ) == 0 );
 
     /* mbedtls_cipher_get_type() */
     TEST_INVALID_PARAM_RET(
         MBEDTLS_CIPHER_NONE,
         mbedtls_cipher_get_type( NULL ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_CIPHER_NONE,
-        mbedtls_cipher_get_type( &invalid_ctx ) );
+    TEST_ASSERT(
+        mbedtls_cipher_get_type( &invalid_ctx ) ==
+        MBEDTLS_CIPHER_NONE);
 
     /* mbedtls_cipher_get_name() */
     TEST_INVALID_PARAM_RET( 0, mbedtls_cipher_get_name( NULL ) );
-    TEST_INVALID_PARAM_RET( 0, mbedtls_cipher_get_name( &invalid_ctx ) );
+    TEST_ASSERT( mbedtls_cipher_get_name( &invalid_ctx ) == 0 );
 
     /* mbedtls_cipher_get_key_bitlen() */
     TEST_INVALID_PARAM_RET(
         MBEDTLS_KEY_LENGTH_NONE,
         mbedtls_cipher_get_key_bitlen( NULL ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_KEY_LENGTH_NONE,
-        mbedtls_cipher_get_key_bitlen( &invalid_ctx ) );
+    TEST_ASSERT( mbedtls_cipher_get_key_bitlen( &invalid_ctx ) ==
+                 MBEDTLS_KEY_LENGTH_NONE );
 
     /* mbedtls_cipher_get_operation() */
     TEST_INVALID_PARAM_RET(
         MBEDTLS_OPERATION_NONE,
         mbedtls_cipher_get_operation( NULL ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_OPERATION_NONE,
-        mbedtls_cipher_get_operation( &invalid_ctx ) );
+    TEST_ASSERT( mbedtls_cipher_get_operation( &invalid_ctx ) ==
+                 MBEDTLS_OPERATION_NONE );
 
     /* mbedtls_cipher_setkey() */
     TEST_INVALID_PARAM_RET(
@@ -103,12 +99,12 @@
                                valid_buffer,
                                valid_bitlen,
                                valid_operation ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_setkey( &invalid_ctx,
                                valid_buffer,
                                valid_bitlen,
-                               valid_operation ) );
+                               valid_operation ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_setkey( &valid_ctx,
@@ -128,11 +124,11 @@
         mbedtls_cipher_set_iv( NULL,
                                valid_buffer,
                                valid_size ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_set_iv( &invalid_ctx,
                                valid_buffer,
-                               valid_size ) );
+                               valid_size ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_set_iv( &valid_ctx,
@@ -142,8 +138,8 @@
     /* mbedtls_cipher_reset() */
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
                             mbedtls_cipher_reset( NULL ) );
-    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
-                            mbedtls_cipher_reset( &invalid_ctx ) );
+    TEST_ASSERT( mbedtls_cipher_reset( &invalid_ctx ) ==
+                 MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     /* mbedtls_cipher_update_ad() */
@@ -152,11 +148,11 @@
         mbedtls_cipher_update_ad( NULL,
                                   valid_buffer,
                                   valid_size ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_update_ad( &invalid_ctx,
                                   valid_buffer,
-                                  valid_size ) );
+                                  valid_size ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_update_ad( &valid_ctx,
@@ -168,9 +164,8 @@
     /* mbedtls_cipher_set_padding_mode() */
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
                             mbedtls_cipher_set_padding_mode( NULL, valid_mode ) );
-    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
-                            mbedtls_cipher_set_padding_mode( &invalid_ctx,
-                                                             valid_mode ) );
+    TEST_ASSERT( mbedtls_cipher_set_padding_mode( &invalid_ctx, valid_mode ) ==
+                 MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 #endif
 
     /* mbedtls_cipher_update() */
@@ -181,13 +176,13 @@
                                valid_size,
                                valid_buffer,
                                &size_t_var ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_update( &invalid_ctx,
                                valid_buffer,
                                valid_size,
                                valid_buffer,
-                               &size_t_var ) );
+                               &size_t_var ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_update( &valid_ctx,
@@ -213,11 +208,11 @@
         mbedtls_cipher_finish( NULL,
                                valid_buffer,
                                &size_t_var ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_finish( &invalid_ctx,
                                valid_buffer,
-                               &size_t_var ) );
+                               &size_t_var ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_finish( &valid_ctx,
@@ -236,11 +231,11 @@
         mbedtls_cipher_write_tag( NULL,
                                   valid_buffer,
                                   valid_size ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_write_tag( &invalid_ctx,
                                   valid_buffer,
-                                  valid_size ) );
+                                  valid_size ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_write_tag( &valid_ctx,
@@ -253,11 +248,11 @@
         mbedtls_cipher_check_tag( NULL,
                                   valid_buffer,
                                   valid_size ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_check_tag( &invalid_ctx,
                                   valid_buffer,
-                                  valid_size ) );
+                                  valid_size ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_check_tag( &valid_ctx,
@@ -272,12 +267,12 @@
                               valid_buffer, valid_size,
                               valid_buffer, valid_size,
                               valid_buffer, &size_t_var ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_crypt( &invalid_ctx,
                               valid_buffer, valid_size,
                               valid_buffer, valid_size,
-                              valid_buffer, &size_t_var ) );
+                              valid_buffer, &size_t_var ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_crypt( &valid_ctx,
@@ -313,14 +308,14 @@
                                      valid_buffer, valid_size,
                                      valid_buffer, &size_t_var,
                                      valid_buffer, valid_size ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_auth_encrypt( &invalid_ctx,
                                      valid_buffer, valid_size,
                                      valid_buffer, valid_size,
                                      valid_buffer, valid_size,
                                      valid_buffer, &size_t_var,
-                                     valid_buffer, valid_size ) );
+                                     valid_buffer, valid_size ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_auth_encrypt( &valid_ctx,
@@ -379,14 +374,14 @@
                                      valid_buffer, valid_size,
                                      valid_buffer, &size_t_var,
                                      valid_buffer, valid_size ) );
-    TEST_INVALID_PARAM_RET(
-        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
+    TEST_ASSERT(
         mbedtls_cipher_auth_decrypt( &invalid_ctx,
                                      valid_buffer, valid_size,
                                      valid_buffer, valid_size,
                                      valid_buffer, valid_size,
                                      valid_buffer, &size_t_var,
-                                     valid_buffer, valid_size ) );
+                                     valid_buffer, valid_size ) ==
+        MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_INVALID_PARAM_RET(
         MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA,
         mbedtls_cipher_auth_decrypt( &valid_ctx,