New test suite for random generation
Test random generation as a whole. This is different from
test_suite_*_drbg and test_suite_entropy, which respectively test PRNG
modules and entropy collection.
Start with basic tests: good-case tests, and do it twice and compare
the results to validate that entropy collection doesn't repeat itself.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_random.function b/tests/suites/test_suite_random.function
new file mode 100644
index 0000000..744daf5
--- /dev/null
+++ b/tests/suites/test_suite_random.function
@@ -0,0 +1,119 @@
+/* BEGIN_HEADER */
+
+/* Test random generation as a whole. */
+
+#include "mbedtls/ctr_drbg.h"
+#include "mbedtls/entropy.h"
+#include "mbedtls/hmac_drbg.h"
+#include "psa/crypto.h"
+
+/* How many bytes to generate in each test case for repeated generation.
+ * This must be high enough that the probability of generating the same
+ * output twice is infinitesimal, but low enough that random generators
+ * are willing to deliver that much. */
+#define OUTPUT_SIZE 32
+
+/* END_HEADER */
+
+/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C */
+void random_twice_with_ctr_drbg( )
+{
+ mbedtls_entropy_context entropy;
+ mbedtls_ctr_drbg_context drbg;
+ unsigned char output1[OUTPUT_SIZE];
+ unsigned char output2[OUTPUT_SIZE];
+
+ /* First round */
+ mbedtls_entropy_init( &entropy );
+ mbedtls_ctr_drbg_init( &drbg );
+ TEST_EQUAL( 0, mbedtls_ctr_drbg_seed( &drbg,
+ mbedtls_entropy_func, &entropy,
+ NULL, 0 ) );
+ TEST_EQUAL( 0, mbedtls_ctr_drbg_random( &drbg,
+ output1, sizeof( output1 ) ) );
+ mbedtls_ctr_drbg_free( &drbg );
+ mbedtls_entropy_free( &entropy );
+
+ /* Second round */
+ mbedtls_entropy_init( &entropy );
+ mbedtls_ctr_drbg_init( &drbg );
+ TEST_EQUAL( 0, mbedtls_ctr_drbg_seed( &drbg,
+ mbedtls_entropy_func, &entropy,
+ NULL, 0 ) );
+ TEST_EQUAL( 0, mbedtls_ctr_drbg_random( &drbg,
+ output2, sizeof( output2 ) ) );
+ mbedtls_ctr_drbg_free( &drbg );
+ mbedtls_entropy_free( &entropy );
+
+ /* The two rounds must generate different random data. */
+ TEST_ASSERT( memcmp( output1, output2, OUTPUT_SIZE ) != 0 );
+
+exit:
+ mbedtls_ctr_drbg_free( &drbg );
+ mbedtls_entropy_free( &entropy );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_C:MBEDTLS_HMAC_DRBG_C */
+void random_twice_with_hmac_drbg( int md_type )
+{
+ mbedtls_entropy_context entropy;
+ mbedtls_hmac_drbg_context drbg;
+ unsigned char output1[OUTPUT_SIZE];
+ unsigned char output2[OUTPUT_SIZE];
+ const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_type );
+
+ /* First round */
+ mbedtls_entropy_init( &entropy );
+ mbedtls_hmac_drbg_init( &drbg );
+ TEST_EQUAL( 0, mbedtls_hmac_drbg_seed( &drbg, md_info,
+ mbedtls_entropy_func, &entropy,
+ NULL, 0 ) );
+ TEST_EQUAL( 0, mbedtls_hmac_drbg_random( &drbg,
+ output1, sizeof( output1 ) ) );
+ mbedtls_hmac_drbg_free( &drbg );
+ mbedtls_entropy_free( &entropy );
+
+ /* Second round */
+ mbedtls_entropy_init( &entropy );
+ mbedtls_hmac_drbg_init( &drbg );
+ TEST_EQUAL( 0, mbedtls_hmac_drbg_seed( &drbg, md_info,
+ mbedtls_entropy_func, &entropy,
+ NULL, 0 ) );
+ TEST_EQUAL( 0, mbedtls_hmac_drbg_random( &drbg,
+ output2, sizeof( output2 ) ) );
+ mbedtls_hmac_drbg_free( &drbg );
+ mbedtls_entropy_free( &entropy );
+
+ /* The two rounds must generate different random data. */
+ TEST_ASSERT( memcmp( output1, output2, OUTPUT_SIZE ) != 0 );
+
+exit:
+ mbedtls_hmac_drbg_free( &drbg );
+ mbedtls_entropy_free( &entropy );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_PSA_CRYPTO_C:!MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+void random_twice_with_psa_from_psa( )
+{
+ unsigned char output1[OUTPUT_SIZE];
+ unsigned char output2[OUTPUT_SIZE];
+
+ /* First round */
+ PSA_ASSERT( psa_crypto_init( ) );
+ PSA_ASSERT( psa_generate_random( output1, sizeof( output1 ) ) );
+ PSA_DONE( );
+
+ /* Second round */
+ PSA_ASSERT( psa_crypto_init( ) );
+ PSA_ASSERT( psa_generate_random( output2, sizeof( output2 ) ) );
+ PSA_DONE( );
+
+ /* The two rounds must generate different random data. */
+ TEST_ASSERT( memcmp( output1, output2, OUTPUT_SIZE ) != 0 );
+
+exit:
+ PSA_DONE( );
+}
+/* END_CASE */