Make the fallback behavior of mbedtls_test_rnd_buffer_rand optional
If a fallback is not explicitly configured in the
mbedtls_test_rnd_buf_info structure, fail after the buffer is
exhausted.
There is no intended behavior change in this commit: all existing uses
of mbedtls_test_rnd_buffer_rand() have been updated to set
mbedtls_test_rnd_std_rand as the fallback.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/include/test/random.h b/tests/include/test/random.h
index 22b9b5c..b64a072 100644
--- a/tests/include/test/random.h
+++ b/tests/include/test/random.h
@@ -36,8 +36,11 @@
typedef struct
{
- unsigned char *buf;
+ unsigned char *buf; /* Pointer to a buffer of length bytes. */
size_t length;
+ /* If fallback_f_rng is NULL, fail after delivering length bytes. */
+ int ( *fallback_f_rng )( void*, unsigned char *, size_t );
+ void *fallback_p_rng;
} mbedtls_test_rnd_buf_info;
/**
@@ -84,7 +87,9 @@
* the random function is specified by per_call. (Can be between
* 1 and 4)
*
- * After the buffer is empty it will return mbedtls_test_rnd_std_rand().
+ * After the buffer is empty, this function will call the fallback RNG in the
+ * #mbedtls_test_rnd_buf_info structure if there is one, and
+ * will return #MBEDTLS_ERR_ENTROPY_SOURCE_FAILED otherwise.
*/
int mbedtls_test_rnd_buffer_rand( void *rng_state,
unsigned char *output,
diff --git a/tests/src/random.c b/tests/src/random.c
index e01bd4d..7f3f401 100644
--- a/tests/src/random.c
+++ b/tests/src/random.c
@@ -35,6 +35,8 @@
#include <test/random.h>
#include <string.h>
+#include <mbedtls/entropy.h>
+
int mbedtls_test_rnd_std_rand( void *rng_state,
unsigned char *output,
size_t len )
@@ -91,8 +93,16 @@
}
if( len - use_len > 0 )
- return( mbedtls_test_rnd_std_rand( NULL, output + use_len,
- len - use_len ) );
+ {
+ if( info->fallback_f_rng != NULL )
+ {
+ return( info->fallback_f_rng( info->fallback_p_rng,
+ output + use_len,
+ len - use_len ) );
+ }
+ else
+ return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
+ }
return( 0 );
}
diff --git a/tests/suites/test_suite_ecdh.function b/tests/suites/test_suite_ecdh.function
index 3ab96fa..da0531b 100644
--- a/tests/suites/test_suite_ecdh.function
+++ b/tests/suites/test_suite_ecdh.function
@@ -240,6 +240,8 @@
rnd_info_A.buf = rnd_buf_A->x;
rnd_info_A.length = rnd_buf_A->len;
+ rnd_info_A.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ rnd_info_A.fallback_p_rng = NULL;
/* Fix rnd_buf_A->x by shifting it left if necessary */
if( grp.nbits % 8 != 0 )
@@ -256,6 +258,8 @@
rnd_info_B.buf = rnd_buf_B->x;
rnd_info_B.length = rnd_buf_B->len;
+ rnd_info_B.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ rnd_info_B.fallback_p_rng = NULL;
/* Fix rnd_buf_B->x by shifting it left if necessary */
if( grp.nbits % 8 != 0 )
@@ -362,9 +366,13 @@
mbedtls_ecdh_init( &srv );
mbedtls_ecdh_init( &cli );
+ rnd_info_A.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ rnd_info_A.fallback_p_rng = NULL;
rnd_info_A.buf = dA->x;
rnd_info_A.length = dA->len;
+ rnd_info_B.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ rnd_info_B.fallback_p_rng = NULL;
rnd_info_B.buf = dB->x;
rnd_info_B.length = dB->len;
diff --git a/tests/suites/test_suite_ecdsa.function b/tests/suites/test_suite_ecdsa.function
index 8157234..fb6ed46 100644
--- a/tests/suites/test_suite_ecdsa.function
+++ b/tests/suites/test_suite_ecdsa.function
@@ -292,6 +292,8 @@
TEST_ASSERT( mbedtls_mpi_read_string( &d, 16, d_str ) == 0 );
TEST_ASSERT( mbedtls_mpi_read_string( &r_check, 16, r_str ) == 0 );
TEST_ASSERT( mbedtls_mpi_read_string( &s_check, 16, s_str ) == 0 );
+ rnd_info.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ rnd_info.fallback_p_rng = NULL;
rnd_info.buf = rnd_buf->x;
rnd_info.length = rnd_buf->len;
diff --git a/tests/suites/test_suite_pkcs1_v15.function b/tests/suites/test_suite_pkcs1_v15.function
index 068027b..9af6aec 100644
--- a/tests/suites/test_suite_pkcs1_v15.function
+++ b/tests/suites/test_suite_pkcs1_v15.function
@@ -19,6 +19,8 @@
mbedtls_test_rnd_buf_info info;
mbedtls_mpi N, E;
+ info.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ info.fallback_p_rng = NULL;
info.buf = rnd_buf->x;
info.length = rnd_buf->len;
@@ -275,6 +277,8 @@
mbedtls_mpi N, P, Q, E;
mbedtls_test_rnd_buf_info info;
+ info.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ info.fallback_p_rng = NULL;
info.buf = rnd_buf->x;
info.length = rnd_buf->len;
diff --git a/tests/suites/test_suite_pkcs1_v21.function b/tests/suites/test_suite_pkcs1_v21.function
index 97f440d..c23a4ad 100644
--- a/tests/suites/test_suite_pkcs1_v21.function
+++ b/tests/suites/test_suite_pkcs1_v21.function
@@ -18,6 +18,8 @@
mbedtls_test_rnd_buf_info info;
mbedtls_mpi N, E;
+ info.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ info.fallback_p_rng = NULL;
info.buf = rnd_buf->x;
info.length = rnd_buf->len;
@@ -124,6 +126,8 @@
mbedtls_test_rnd_buf_info info;
mbedtls_mpi N, P, Q, E;
+ info.fallback_f_rng = mbedtls_test_rnd_std_rand;
+ info.fallback_p_rng = NULL;
info.buf = rnd_buf->x;
info.length = rnd_buf->len;