Add macro for error code addition
Adds a macro (`MBEDTLS_ERR_ADD`) to add error codes together and check that the
result will not be corrupted. This additional check is only enabled during
testing when `MBEDTLS_TEST_HOOKS` is defined.
Also includes a reference usage example in `rsa.c` where two high-level error
codes could be incorrectly added together under the right conditions. This now
ensures that when this error occurs during testing it will be correctly
reported.
Signed-off-by: Chris Jones <christopher.jones@arm.com>
diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
index cd7731e..d164e9f 100644
--- a/include/mbedtls/error.h
+++ b/include/mbedtls/error.h
@@ -114,6 +114,16 @@
#define MBEDTLS_ERR_ERROR_GENERIC_ERROR -0x0001 /**< Generic error */
#define MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED -0x006E /**< This is a bug in the library */
+#if defined(MBEDTLS_TEST_HOOKS)
+void (*mbedtls_test_err_add_hook)( int, int, const char *, int );
+int mbedtls_err_add( int high, int low, const char *file, int line );
+#define MBEDTLS_ERR_ADD( high, low ) \
+ ( mbedtls_err_add( high, low, __FILE__, __LINE__ ) )
+#else
+#define MBEDTLS_ERR_ADD( high, low ) \
+ ( high + low )
+#endif
+
/**
* \brief Translate a mbed TLS error code into a string representation,
* Result is truncated if necessary and always includes a terminating
diff --git a/library/error.c b/library/error.c
index 901a369..486afed 100644
--- a/library/error.c
+++ b/library/error.c
@@ -210,6 +210,13 @@
#include "mbedtls/xtea.h"
#endif
+#if defined(MBEDTLS_TEST_HOOKS)
+int mbedtls_err_add( int high, int low, const char *file, int line ) {
+ if( mbedtls_test_err_add_hook != NULL )
+ (*mbedtls_test_err_add_hook)( high, low, file, line );
+ return ( high + low );
+}
+#endif
const char * mbedtls_high_level_strerr( int error_code )
{
diff --git a/library/rsa.c b/library/rsa.c
index fea76bf..f4bec46 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -1085,7 +1085,7 @@
mbedtls_mpi_free( &I );
if( ret != 0 && ret >= -0x007f )
- return( MBEDTLS_ERR_RSA_PRIVATE_FAILED + ret );
+ return( MBEDTLS_ERR_ADD( MBEDTLS_ERR_RSA_PRIVATE_FAILED, ret ) );
return( ret );
}
diff --git a/tests/include/test/helpers.h b/tests/include/test/helpers.h
index c3a844b..1fe25d8 100644
--- a/tests/include/test/helpers.h
+++ b/tests/include/test/helpers.h
@@ -278,4 +278,14 @@
void mbedtls_test_mutex_usage_check( void );
#endif /* MBEDTLS_TEST_MUTEX_USAGE */
+#if defined(MBEDTLS_TEST_HOOKS)
+/**
+ * \brief Check that a pure high-level error code is being combined with a
+ * pure low-level error code as otherwise the resultant error code
+ * would be corrupted.
+ */
+void mbedtls_test_err_add_check( int high, int low,
+ const char *file, int line);
+#endif
+
#endif /* TEST_HELPERS_H */
diff --git a/tests/src/helpers.c b/tests/src/helpers.c
index e323275..2c01a58 100644
--- a/tests/src/helpers.c
+++ b/tests/src/helpers.c
@@ -282,3 +282,16 @@
}
}
#endif /* MBEDTLS_CHECK_PARAMS */
+
+#if defined(MBEDTLS_TEST_HOOKS)
+void mbedtls_test_err_add_check( int high, int low,
+ const char *file, int line )
+{
+ if ( high < -0x0FFF && low > -0x007F )
+ {
+ mbedtls_fprintf( stderr, "\nIncorrect error code addition at %s:%d\n",
+ file, line );
+ mbedtls_exit( 1 );
+ }
+}
+#endif /* MBEDTLS_TEST_HOOKS */
diff --git a/tests/suites/main_test.function b/tests/suites/main_test.function
index 36a7d23..6a4758a 100644
--- a/tests/suites/main_test.function
+++ b/tests/suites/main_test.function
@@ -33,6 +33,10 @@
#include "psa/crypto.h"
#endif /* MBEDTLS_USE_PSA_CRYPTO */
+#if defined(MBEDTLS_TEST_HOOKS)
+#include "mbedtls/error.h"
+#endif
+
/* Test code may use deprecated identifiers only if the preprocessor symbol
* MBEDTLS_TEST_DEPRECATED is defined. When building tests, set
* MBEDTLS_TEST_DEPRECATED explicitly if MBEDTLS_DEPRECATED_WARNING is
@@ -279,6 +283,10 @@
*/
int main( int argc, const char *argv[] )
{
+#if defined(MBEDTLS_TEST_HOOKS)
+ mbedtls_test_err_add_hook = &mbedtls_test_err_add_check;
+#endif
+
int ret = mbedtls_test_platform_setup();
if( ret != 0 )
{