Support mbedtls_psa_get_random() in SSL test programs
The SSL test programs can now use mbedtls_psa_get_random() rather than
entropy+DRBG as a random generator. This happens if
the configuration option MBEDTLS_USE_PSA_CRYPTO is enabled, or if
MBEDTLS_TEST_USE_PSA_CRYPTO_RNG is set at build time.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/programs/ssl/ssl_test_lib.c b/programs/ssl/ssl_test_lib.c
index 56e9431..6636e9e 100644
--- a/programs/ssl/ssl_test_lib.c
+++ b/programs/ssl/ssl_test_lib.c
@@ -46,6 +46,7 @@
return 0x5af2a056;
}
+#if !defined(MBEDTLS_TEST_USE_PSA_CRYPTO_RNG)
static int dummy_entropy( void *data, unsigned char *output, size_t len )
{
size_t i;
@@ -60,9 +61,15 @@
}
return( ret );
}
+#endif
void rng_init( rng_context_t *rng )
{
+#if defined(MBEDTLS_TEST_USE_PSA_CRYPTO_RNG)
+ (void) rng;
+ psa_crypto_init( );
+#else /* !MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
+
#if defined(MBEDTLS_CTR_DRBG_C)
mbedtls_ctr_drbg_init( &rng->drbg );
#elif defined(MBEDTLS_HMAC_DRBG_C)
@@ -72,6 +79,7 @@
#endif
mbedtls_entropy_init( &rng->entropy );
+#endif /* !MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
}
int rng_seed( rng_context_t *rng, int reproducible, const char *pers )
@@ -84,6 +92,18 @@
return( -1 );
}
#endif
+#if defined(MBEDTLS_TEST_USE_PSA_CRYPTO_RNG)
+ /* The PSA crypto RNG does its own seeding. */
+ (void) rng;
+ (void) pers;
+ if( reproducible )
+ {
+ mbedtls_fprintf( stderr,
+ "The PSA RNG does not support reproducible mode.\n" );
+ return( -1 );
+ }
+ return( 0 );
+#else /* !MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
int ( *f_entropy )( void *, unsigned char *, size_t ) =
( reproducible ? dummy_entropy : mbedtls_entropy_func );
@@ -108,9 +128,9 @@
f_entropy, &rng->entropy,
(const unsigned char *) pers,
strlen( pers ) );
-#else
+#else /* !defined(MBEDTLS_CTR_DRBG_C) && !defined(MBEDTLS_HMAC_DRBG_C) */
#error "No DRBG available"
-#endif
+#endif /* !defined(MBEDTLS_CTR_DRBG_C) && !defined(MBEDTLS_HMAC_DRBG_C) */
if( ret != 0 )
{
@@ -118,12 +138,21 @@
(unsigned int) -ret );
return( ret );
}
+#endif /* !MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
return( 0 );
}
void rng_free( rng_context_t *rng )
{
+#if defined(MBEDTLS_TEST_USE_PSA_CRYPTO_RNG)
+ (void) rng;
+ /* Deinitialize the PSA crypto subsystem. This deactivates all PSA APIs.
+ * This is ok because none of our applications try to do any crypto after
+ * deinitializing the RNG. */
+ mbedtls_psa_crypto_free( );
+#else /* !MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
+
#if defined(MBEDTLS_CTR_DRBG_C)
mbedtls_ctr_drbg_free( &rng->drbg );
#elif defined(MBEDTLS_HMAC_DRBG_C)
@@ -133,11 +162,18 @@
#endif
mbedtls_entropy_free( &rng->entropy );
+#endif /* !MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
}
int rng_get( void *p_rng, unsigned char *output, size_t output_len )
{
+#if defined(MBEDTLS_TEST_USE_PSA_CRYPTO_RNG)
+ (void) p_rng;
+ return( mbedtls_psa_get_random( MBEDTLS_PSA_RANDOM_STATE,
+ output, output_len ) );
+#else /* !MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
rng_context_t *rng = p_rng;
+
#if defined(MBEDTLS_CTR_DRBG_C)
return( mbedtls_ctr_drbg_random( &rng->drbg, output, output_len ) );
#elif defined(MBEDTLS_HMAC_DRBG_C)
@@ -145,6 +181,8 @@
#else
#error "No DRBG available"
#endif
+
+#endif /* !MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
}
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
diff --git a/programs/ssl/ssl_test_lib.h b/programs/ssl/ssl_test_lib.h
index 861e82a..d605a94 100644
--- a/programs/ssl/ssl_test_lib.h
+++ b/programs/ssl/ssl_test_lib.h
@@ -130,10 +130,38 @@
mbedtls_time_t dummy_constant_time( mbedtls_time_t* time );
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+/* If MBEDTLS_TEST_USE_PSA_CRYPTO_RNG is defined, the SSL test programs will use
+ * mbedtls_psa_get_random() rather than entropy+DRBG as a random generator.
+ *
+ * The constraints are:
+ * - Without the entropy module, the PSA RNG is the only option.
+ * - Without at least one of the DRBG modules, the PSA RNG is the only option.
+ * - The PSA RNG does not support explicit seeding, so it is incompatible with
+ * the reproducible mode used by test programs.
+ * - For good overall test coverage, there should be at least one configuration
+ * where the test programs use the PSA RNG while the PSA RNG is itself based
+ * on entropy+DRBG, and at least one configuration where the test programs
+ * do not use the PSA RNG even though it's there.
+ *
+ * A simple choice that meets the constraints is to use the PSA RNG whenever
+ * MBEDTLS_USE_PSA_CRYPTO is enabled. There's no real technical reason the
+ * choice to use the PSA RNG in the test programs and the choice to use
+ * PSA crypto when TLS code needs crypto have to be tied together, but it
+ * happens to be a good match. It's also a good match from an application
+ * perspective: either PSA is preferred for TLS (both for crypto and for
+ * random generation) or it isn't.
+ */
+#define MBEDTLS_TEST_USE_PSA_CRYPTO_RNG
+#endif
+
/** A context for random number generation (RNG).
*/
typedef struct
{
+#if defined(MBEDTLS_TEST_USE_PSA_CRYPTO_RNG)
+ unsigned char dummy;
+#else /* MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
mbedtls_entropy_context entropy;
#if defined(MBEDTLS_CTR_DRBG_C)
mbedtls_ctr_drbg_context drbg;
@@ -142,6 +170,7 @@
#else
#error "No DRBG available"
#endif
+#endif /* MBEDTLS_TEST_USE_PSA_CRYPTO_RNG */
} rng_context_t;
/** Initialize the RNG.
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index d1366e8..91d457a 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -1018,12 +1018,16 @@
scripts/config.py unset MBEDTLS_HMAC_DRBG_C
scripts/config.py unset MBEDTLS_ECDSA_DETERMINISTIC # requires HMAC_DRBG
scripts/config.py set MBEDTLS_ECP_NO_INTERNAL_RNG
- make CFLAGS="$ASAN_CFLAGS -O2" LDFLAGS="$ASAN_CFLAGS"
+ # When MBEDTLS_USE_PSA_CRYPTO is disabled and there is no DRBG,
+ # the SSL test programs don't have an RNG and can't work. Explicitly
+ # make them use the PSA RNG with -DMBEDTLS_TEST_USE_PSA_CRYPTO_RNG.
+ make CFLAGS="$ASAN_CFLAGS -O2 -DMBEDTLS_TEST_USE_PSA_CRYPTO_RNG" LDFLAGS="$ASAN_CFLAGS"
msg "test: PSA_CRYPTO_EXTERNAL_RNG minus *_DRBG, classic crypto - main suites"
make test
- # no SSL tests as they all depend on having a DRBG
+ msg "test: PSA_CRYPTO_EXTERNAL_RNG minus *_DRBG, classic crypto - ssl-opt.sh (subset)"
+ if_build_succeeded tests/ssl-opt.sh -f 'Default'
}
component_test_psa_external_rng_no_drbg_use_psa () {
@@ -1038,6 +1042,9 @@
msg "test: PSA_CRYPTO_EXTERNAL_RNG minus *_DRBG, PSA crypto - main suites"
make test
+
+ msg "test: PSA_CRYPTO_EXTERNAL_RNG minus *_DRBG, PSA crypto - ssl-opt.sh (subset)"
+ if_build_succeeded tests/ssl-opt.sh -f 'Default\|opaque'
}
component_test_psa_external_rng_use_psa_crypto () {
