fips: rework the option handling code

Add option for restricting digests available to DRBGs.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/20521)

1 files changed, 74 insertions, 49 deletions

diff --git a/providers/fips/fipsprov.c b/providers/fips/fipsprov.c
index a16c379fba..d583bb9f2a 100644
--- a/providers/fips/fipsprov.c
+++ b/providers/fips/fipsprov.c
@@ -46,8 +46,6 @@ static OSSL_FUNC_provider_query_operation_fn fips_query;
 #define UNAPPROVED_ALG(NAMES, FUNC) UNAPPROVED_ALGC(NAMES, FUNC, NULL)
 
 extern OSSL_FUNC_core_thread_start_fn *c_thread_start;
-int FIPS_security_check_enabled(OSSL_LIB_CTX *libctx);
-int FIPS_tls_prf_ems_check(OSSL_LIB_CTX *libctx);
 
 /*
  * Should these function pointers be stored in the provider side provctx? Could
@@ -79,27 +77,34 @@ static OSSL_FUNC_BIO_vsnprintf_fn *c_BIO_vsnprintf;
 static OSSL_FUNC_self_test_cb_fn *c_stcbfn = NULL;
 static OSSL_FUNC_core_get_libctx_fn *c_get_libctx = NULL;
 
+typedef struct {
+    const char *option;
+    unsigned char enabled;
+} FIPS_OPTION;
+
 typedef struct fips_global_st {
     const OSSL_CORE_HANDLE *handle;
     SELF_TEST_POST_PARAMS selftest_params;
-    int fips_security_checks;
-    int fips_tls1_prf_ems_check;
-    const char *fips_security_check_option;
-    const char *fips_tls1_prf_ems_check_option;
+    FIPS_OPTION fips_security_checks;
+    FIPS_OPTION fips_tls1_prf_ems_check;
+    FIPS_OPTION fips_restricted_drgb_digests;
 } FIPS_GLOBAL;
 
+static void init_fips_option(FIPS_OPTION *opt, int enabled)
+{
+    opt->enabled = enabled;
+    opt->option = enabled ? "1" : "0";
+}
+
 void *ossl_fips_prov_ossl_ctx_new(OSSL_LIB_CTX *libctx)
 {
     FIPS_GLOBAL *fgbl = OPENSSL_zalloc(sizeof(*fgbl));
 
     if (fgbl == NULL)
         return NULL;
-    fgbl->fips_security_checks = 1;
-    fgbl->fips_security_check_option = "1";
-
-    fgbl->fips_tls1_prf_ems_check = 0; /* Disabled by default */
-    fgbl->fips_tls1_prf_ems_check_option = "0";
-
+    init_fips_option(&fgbl->fips_security_checks, 1);
+    init_fips_option(&fgbl->fips_tls1_prf_ems_check, 0); /* Disabled by default */
+    init_fips_option(&fgbl->fips_restricted_drgb_digests, 0);
     return fgbl;
 }
 
@@ -116,6 +121,7 @@ static const OSSL_PARAM fips_param_types[] = {
     OSSL_PARAM_DEFN(OSSL_PROV_PARAM_STATUS, OSSL_PARAM_INTEGER, NULL, 0),
     OSSL_PARAM_DEFN(OSSL_PROV_PARAM_SECURITY_CHECKS, OSSL_PARAM_INTEGER, NULL, 0),
     OSSL_PARAM_DEFN(OSSL_PROV_PARAM_TLS1_PRF_EMS_CHECK, OSSL_PARAM_INTEGER, NULL, 0),
+    OSSL_PARAM_DEFN(OSSL_PROV_PARAM_DRBG_TRUNC_DIGEST, OSSL_PARAM_INTEGER, NULL, 0),
     OSSL_PARAM_END
 };
 
@@ -129,7 +135,7 @@ static int fips_get_params_from_core(FIPS_GLOBAL *fgbl)
     * OSSL_PROV_FIPS_PARAM_SECURITY_CHECKS and
     * OSSL_PROV_FIPS_PARAM_TLS1_PRF_EMS_CHECK are not self test parameters.
     */
-    OSSL_PARAM core_params[9], *p = core_params;
+    OSSL_PARAM core_params[10], *p = core_params;
 
     *p++ = OSSL_PARAM_construct_utf8_ptr(
             OSSL_PROV_PARAM_CORE_MODULE_FILENAME,
@@ -155,14 +161,21 @@ static int fips_get_params_from_core(FIPS_GLOBAL *fgbl)
             OSSL_PROV_FIPS_PARAM_CONDITIONAL_ERRORS,
             (char **)&fgbl->selftest_params.conditional_error_check,
             sizeof(fgbl->selftest_params.conditional_error_check));
-    *p++ = OSSL_PARAM_construct_utf8_ptr(
-            OSSL_PROV_FIPS_PARAM_SECURITY_CHECKS,
-            (char **)&fgbl->fips_security_check_option,
-            sizeof(fgbl->fips_security_check_option));
-    *p++ = OSSL_PARAM_construct_utf8_ptr(
-            OSSL_PROV_FIPS_PARAM_TLS1_PRF_EMS_CHECK,
-            (char **)&fgbl->fips_tls1_prf_ems_check_option,
-            sizeof(fgbl->fips_tls1_prf_ems_check_option));
+
+/* FIPS features can be enabled or disabled independently */
+#define FIPS_FEATURE_OPTION(fgbl, pname, field)                         \
+    *p++ = OSSL_PARAM_construct_utf8_ptr(                               \
+            pname, (char **)&fgbl->field.option,                        \
+            sizeof(fgbl->field.option))
+
+    FIPS_FEATURE_OPTION(fgbl, OSSL_PROV_FIPS_PARAM_SECURITY_CHECKS,
+                        fips_security_checks);
+    FIPS_FEATURE_OPTION(fgbl, OSSL_PROV_FIPS_PARAM_TLS1_PRF_EMS_CHECK,
+                        fips_tls1_prf_ems_check);
+    FIPS_FEATURE_OPTION(fgbl, OSSL_PROV_FIPS_PARAM_DRBG_TRUNC_DIGEST,
+                        fips_restricted_drgb_digests);
+#undef FIPS_FEATURE_OPTION
+
     *p = OSSL_PARAM_construct_end();
 
     if (!c_get_params(fgbl->handle, core_params)) {
@@ -196,12 +209,19 @@ static int fips_get_params(void *provctx, OSSL_PARAM params[])
     p = OSSL_PARAM_locate(params, OSSL_PROV_PARAM_STATUS);
     if (p != NULL && !OSSL_PARAM_set_int(p, ossl_prov_is_running()))
         return 0;
-    p = OSSL_PARAM_locate(params, OSSL_PROV_PARAM_SECURITY_CHECKS);
-    if (p != NULL && !OSSL_PARAM_set_int(p, fgbl->fips_security_checks))
-        return 0;
-    p = OSSL_PARAM_locate(params, OSSL_PROV_PARAM_TLS1_PRF_EMS_CHECK);
-    if (p != NULL && !OSSL_PARAM_set_int(p, fgbl->fips_tls1_prf_ems_check))
-        return 0;
+
+#define FIPS_FEATURE_GET(fgbl, pname, field)                            \
+    p = OSSL_PARAM_locate(params, pname);                               \
+    if (p != NULL && !OSSL_PARAM_set_int(p, fgbl->field.enabled))       \
+        return 0
+
+    FIPS_FEATURE_GET(fgbl, OSSL_PROV_PARAM_SECURITY_CHECKS,
+                     fips_security_checks);
+    FIPS_FEATURE_GET(fgbl, OSSL_PROV_PARAM_TLS1_PRF_EMS_CHECK,
+                     fips_tls1_prf_ems_check);
+    FIPS_FEATURE_GET(fgbl, OSSL_PROV_PARAM_DRBG_TRUNC_DIGEST,
+                     fips_restricted_drgb_digests);
+#undef FIPS_FEATURE_GET
     return 1;
 }
 
@@ -708,15 +728,21 @@ int OSSL_provider_init_int(const OSSL_CORE_HANDLE *handle,
         && strcmp(fgbl->selftest_params.conditional_error_check, "0") == 0)
         SELF_TEST_disable_conditional_error_state();
 
-    /* Disable the security check if it's disabled in the fips config file. */
-    if (fgbl->fips_security_check_option != NULL
-        && strcmp(fgbl->fips_security_check_option, "0") == 0)
-        fgbl->fips_security_checks = 0;
+    /* Enable or disable FIPS provider options */
+#define FIPS_SET_OPTION(fgbl, field)                                            \
+    if (fgbl->field.option != NULL) {                                       \
+        if (strcmp(fgbl->field.option, "1") == 0)                           \
+            fgbl->field.enabled = 1;                                        \
+        else if (strcmp(fgbl->field.option, "0") == 0)                      \
+            fgbl->field.enabled = 0;                                        \
+        else                                                                \
+            goto err;                                                       \
+    }
 
-    /* Enable the ems check if it's enabled in the fips config file. */
-    if (fgbl->fips_tls1_prf_ems_check_option != NULL
-        && strcmp(fgbl->fips_tls1_prf_ems_check_option, "1") == 0)
-        fgbl->fips_tls1_prf_ems_check = 1;
+    FIPS_SET_OPTION(fgbl, fips_security_checks);
+    FIPS_SET_OPTION(fgbl, fips_tls1_prf_ems_check);
+    FIPS_SET_OPTION(fgbl, fips_restricted_drgb_digests);
+#undef FIPS_SET_OPTION
 
     ossl_prov_cache_exported_algorithms(fips_ciphers, exported_fips_ciphers);
 
@@ -905,21 +931,20 @@ int BIO_snprintf(char *buf, size_t n, const char *format, ...)
     return ret;
 }
 
-int FIPS_security_check_enabled(OSSL_LIB_CTX *libctx)
-{
-    FIPS_GLOBAL *fgbl = ossl_lib_ctx_get_data(libctx,
-                                              OSSL_LIB_CTX_FIPS_PROV_INDEX);
-
-    return fgbl->fips_security_checks;
-}
-
-int FIPS_tls_prf_ems_check(OSSL_LIB_CTX *libctx)
-{
-    FIPS_GLOBAL *fgbl = ossl_lib_ctx_get_data(libctx,
-                                              OSSL_LIB_CTX_FIPS_PROV_INDEX);
+#define FIPS_FEATURE_CHECK(fname, field)                                    \
+    int fname(OSSL_LIB_CTX *libctx);                                        \
+    int fname(OSSL_LIB_CTX *libctx)                                         \
+    {                                                                       \
+        FIPS_GLOBAL *fgbl =                                                 \
+            ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_FIPS_PROV_INDEX);    \
+        return fgbl->field.enabled;                                         \
+    }
 
-    return fgbl->fips_tls1_prf_ems_check;
-}
+FIPS_FEATURE_CHECK(FIPS_security_check_enabled, fips_security_checks)
+FIPS_FEATURE_CHECK(FIPS_tls_prf_ems_check, fips_tls1_prf_ems_check)
+FIPS_FEATURE_CHECK(FIPS_restricted_drbg_digests_enabled,
+                   fips_restricted_drgb_digests)
+#undef FIPS_FEATURE_CHECK
 
 void OSSL_SELF_TEST_get_callback(OSSL_LIB_CTX *libctx, OSSL_CALLBACK **cb,
                                  void **cbarg)