Remove config option MBEDTLS_ECP_NO_INTERNAL_RNG

It was used to remove the code used when mbedtls_ecp_mul() received a
NULL RNG parameter. This code is no longer relevant (as the RNG may no
longer be NULL) and will be unconditionally removed in the next commit.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>

include/mbedtls/check_config.h

@@ -150,14 +150,6 @@
 #error "MBEDTLS_ECP_C defined, but not all prerequisites"
 #endif
 
-#if defined(MBEDTLS_ECP_C) && !(            \
-    defined(MBEDTLS_ECP_ALT) ||             \
-    defined(MBEDTLS_CTR_DRBG_C) ||          \
-    defined(MBEDTLS_HMAC_DRBG_C) ||         \
-    defined(MBEDTLS_ECP_NO_INTERNAL_RNG))
-#error "MBEDTLS_ECP_C requires a DRBG module unless MBEDTLS_ECP_NO_INTERNAL_RNG is defined or an alternative implementation is used"
-#endif
-
 #if defined(MBEDTLS_PK_PARSE_C) && !defined(MBEDTLS_ASN1_PARSE_C)
 #error "MBEDTLS_PK_PARSE_C defined, but not all prerequesites"
 #endif

include/mbedtls/config.h

@@ -651,28 +651,6 @@
  */
 #define MBEDTLS_ECP_NIST_OPTIM
 
-/**
- * \def MBEDTLS_ECP_NO_INTERNAL_RNG
- *
- * When this option is disabled, mbedtls_ecp_mul() will make use of an
- * internal RNG when called with a NULL \c f_rng argument, in order to protect
- * against some side-channel attacks.
- *
- * This protection introduces a dependency of the ECP module on one of the
- * DRBG modules. For very constrained implementations that don't require this
- * protection (for example, because you're only doing signature verification,
- * so not manipulating any secret, or because local/physical side-channel
- * attacks are outside your threat model), it might be desirable to get rid of
- * that dependency.
- *
- * \warning Enabling this option makes some uses of ECP vulnerable to some
- * side-channel attacks. Only enable it if you know that's not a problem for
- * your use case.
- *
- * Uncomment this macro to disable some counter-measures in ECP.
- */
-//#define MBEDTLS_ECP_NO_INTERNAL_RNG
-
 /**
  * \def MBEDTLS_ECP_RESTARTABLE
  *

scripts/config.py

@@ -181,7 +181,6 @@ EXCLUDE_FROM_FULL = frozenset([
     'MBEDTLS_DEPRECATED_WARNING', # conflicts with deprecated options
     'MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED', # influences the use of ECDH in TLS
     'MBEDTLS_ECP_NO_FALLBACK', # removes internal ECP implementation
-    'MBEDTLS_ECP_NO_INTERNAL_RNG', # removes a feature
     'MBEDTLS_ECP_RESTARTABLE', # incompatible with USE_PSA_CRYPTO
     'MBEDTLS_ENTROPY_FORCE_SHA256', # interacts with CTR_DRBG_128_BIT_KEY
     'MBEDTLS_HAVE_SSE2', # hardware dependency

tests/scripts/all.sh

@@ -1000,7 +1000,6 @@ component_test_psa_external_rng_no_drbg_classic () {
     scripts/config.py unset MBEDTLS_CTR_DRBG_C
     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
     # 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.
@@ -1023,7 +1022,6 @@ component_test_psa_external_rng_no_drbg_use_psa () {
     scripts/config.py unset MBEDTLS_CTR_DRBG_C
     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"
 
     msg "test: PSA_CRYPTO_EXTERNAL_RNG minus *_DRBG, PSA crypto - main suites"
@@ -1048,43 +1046,6 @@ component_test_psa_external_rng_use_psa_crypto () {
     if_build_succeeded tests/ssl-opt.sh -f 'Default\|opaque'
 }
 
-component_test_ecp_no_internal_rng () {
-    msg "build: Default plus ECP_NO_INTERNAL_RNG minus DRBG modules"
-    scripts/config.py set MBEDTLS_ECP_NO_INTERNAL_RNG
-    scripts/config.py unset MBEDTLS_CTR_DRBG_C
-    scripts/config.py unset MBEDTLS_HMAC_DRBG_C
-    scripts/config.py unset MBEDTLS_ECDSA_DETERMINISTIC # requires HMAC_DRBG
-    scripts/config.py unset MBEDTLS_PSA_CRYPTO_C # requires a DRBG
-    scripts/config.py unset MBEDTLS_PSA_CRYPTO_STORAGE_C # requires PSA Crypto
-
-    CC=gcc cmake -D CMAKE_BUILD_TYPE:String=Asan .
-    make
-
-    msg "test: ECP_NO_INTERNAL_RNG, no DRBG module"
-    make test
-
-    # no SSL tests as they all depend on having a DRBG
-}
-
-component_test_ecp_restartable_no_internal_rng () {
-    msg "build: Default plus ECP_RESTARTABLE and ECP_NO_INTERNAL_RNG, no DRBG"
-    scripts/config.py set MBEDTLS_ECP_NO_INTERNAL_RNG
-    scripts/config.py set MBEDTLS_ECP_RESTARTABLE
-    scripts/config.py unset MBEDTLS_CTR_DRBG_C
-    scripts/config.py unset MBEDTLS_HMAC_DRBG_C
-    scripts/config.py unset MBEDTLS_ECDSA_DETERMINISTIC # requires HMAC_DRBG
-    scripts/config.py unset MBEDTLS_PSA_CRYPTO_C # requires CTR_DRBG
-    scripts/config.py unset MBEDTLS_PSA_CRYPTO_STORAGE_C # requires PSA Crypto
-
-    CC=gcc cmake -D CMAKE_BUILD_TYPE:String=Asan .
-    make
-
-    msg "test: ECP_RESTARTABLE and ECP_NO_INTERNAL_RNG, no DRBG module"
-    make test
-
-    # no SSL tests as they all depend on having a DRBG
-}
-
 component_test_everest () {
     msg "build: Everest ECDH context (ASan build)" # ~ 6 min
     scripts/config.py set MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED