Support set *_drbg reseed interval before seed
mbedtls_ctr_drbg_set_reseed_interval() and
mbedtls_hmac_drbg_set_reseed_interval() can now be called before
their seed functions and the reseed_interval value will persist.
Previously it would be overwritten with the default value.
*_drbg_reseed_interval is now set in init() and free().
mbedtls_ctr_drbg_free() and mbedtls_hmac_drbg_free() now
reset the drbg context to the state immediately after init().
Tests:
- Added test to check that DRBG reseeds when reseed_counter
reaches reseed_interval, if reseed_interval set before seed
and reseed_interval is less than MBEDTLS_*_DRBG_RESEED_INTERVAL.
Signed-off-by: gacquroff <gavina352@gmail.com>
diff --git a/tests/suites/test_suite_ctr_drbg.function b/tests/suites/test_suite_ctr_drbg.function
index 01050d9..d6cf828 100644
--- a/tests/suites/test_suite_ctr_drbg.function
+++ b/tests/suites/test_suite_ctr_drbg.function
@@ -206,13 +206,16 @@
memset( out, 0, sizeof( out ) );
memset( add, 0, sizeof( add ) );
+ /* Set reseed interval before seed */
+ mbedtls_ctr_drbg_set_reseed_interval( &ctx, 2 * reps );
+
/* Init must use entropy */
last_idx = test_offset_idx;
TEST_ASSERT( mbedtls_ctr_drbg_seed( &ctx, mbedtls_test_entropy_func, entropy, NULL, 0 ) == 0 );
TEST_ASSERT( last_idx < test_offset_idx );
- /* By default, PR is off and reseed_interval is large,
- * so the next few calls should not use entropy */
+ /* By default, PR is off, and reseed interval was set to
+ * 2 * reps so the next few calls should not use entropy */
last_idx = test_offset_idx;
for( i = 0; i < reps; i++ )
{
@@ -228,15 +231,16 @@
TEST_ASSERT( out[sizeof( out ) - 2] == 0 );
TEST_ASSERT( out[sizeof( out ) - 1] == 0 );
- /* Set reseed_interval to the number of calls done,
- * so the next call should reseed */
- mbedtls_ctr_drbg_set_reseed_interval( &ctx, 2 * reps );
+ /* There have been 2 * reps calls to random. The next call should reseed */
TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( last_idx < test_offset_idx );
- /* The new few calls should not reseed */
+ /* Set reseed interval after seed */
+ mbedtls_ctr_drbg_set_reseed_interval( &ctx, 4 * reps + 1 );
+
+ /* The next few calls should not reseed */
last_idx = test_offset_idx;
- for( i = 0; i < reps / 2; i++ )
+ for( i = 0; i < (2 * reps); i++ )
{
TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, out, sizeof( out ) ,
diff --git a/tests/suites/test_suite_hmac_drbg.function b/tests/suites/test_suite_hmac_drbg.function
index 13bc400..fbbb1bd 100644
--- a/tests/suites/test_suite_hmac_drbg.function
+++ b/tests/suites/test_suite_hmac_drbg.function
@@ -49,14 +49,17 @@
md_info = mbedtls_md_info_from_type( md_alg );
TEST_ASSERT( md_info != NULL );
+ /* Set reseed interval before seed */
+ mbedtls_hmac_drbg_set_reseed_interval( &ctx, 2 * reps );
+
/* Init must use entropy */
last_len = entropy.len;
TEST_ASSERT( mbedtls_hmac_drbg_seed( &ctx, md_info, mbedtls_test_entropy_func, &entropy,
NULL, 0 ) == 0 );
TEST_ASSERT( entropy.len < last_len );
- /* By default, PR is off and reseed_interval is large,
- * so the next few calls should not use entropy */
+ /* By default, PR is off, and reseed interval was set to
+ * 2 * reps so the next few calls should not use entropy */
last_len = entropy.len;
for( i = 0; i < reps; i++ )
{
@@ -72,15 +75,16 @@
TEST_ASSERT( out[sizeof( out ) - 2] == 0 );
TEST_ASSERT( out[sizeof( out ) - 1] == 0 );
- /* Set reseed_interval to the number of calls done,
- * so the next call should reseed */
- mbedtls_hmac_drbg_set_reseed_interval( &ctx, 2 * reps );
+ /* There have been 2 * reps calls to random. The next call should reseed */
TEST_ASSERT( mbedtls_hmac_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( entropy.len < last_len );
+ /* Set reseed interval after seed */
+ mbedtls_hmac_drbg_set_reseed_interval( &ctx, 4 * reps + 1);
+
/* The new few calls should not reseed */
last_len = entropy.len;
- for( i = 0; i < reps / 2; i++ )
+ for( i = 0; i < (2 * reps); i++ )
{
TEST_ASSERT( mbedtls_hmac_drbg_random( &ctx, out, sizeof( out ) ) == 0 );
TEST_ASSERT( mbedtls_hmac_drbg_random_with_add( &ctx, out, sizeof( out ) ,
@@ -189,7 +193,7 @@
TEST_ASSERT( mbedtls_hmac_drbg_random_with_add( &ctx, my_output, output->len,
add2->x, add2->len ) == 0 );
- /* clear for second run */
+ /* Reset context for second run */
mbedtls_hmac_drbg_free( &ctx );
TEST_ASSERT( memcmp( my_output, output->x, output->len ) == 0 );