crypto: drbg - Simplify algorithm registration

Now that "drbg_pr_hmac_sha512" and "drbg_nopr_hmac_sha512" are the only
crypto_rng algorithms left in crypto/drbg.c, simplify the algorithm
registration logic to register these more directly without relying on
the drbg_cores[] array (which will be removed).

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 81bccacd3595d1d4b8c15bd1fb0558088657c3a5..4a778d0d1fc4a8b6976daac21f74e29b7c247b32 100644 (file)
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1145,86 +1145,56 @@ static inline int __init drbg_healthcheck_sanity(void)
        return rc;
 }
 
-static struct rng_alg drbg_algs[22];
-
-/*
- * Fill the array drbg_algs used to register the different DRBGs
- * with the kernel crypto API. To fill the array, the information
- * from drbg_cores[] is used.
- */
-static inline void __init drbg_fill_array(struct rng_alg *alg,
-                                         const struct drbg_core *core, int pr)
-{
-       int pos = 0;
-       static int priority = 200;
-
-       memcpy(alg->base.cra_name, "stdrng", 6);
-       if (pr) {
-               memcpy(alg->base.cra_driver_name, "drbg_pr_", 8);
-               pos = 8;
-       } else {
-               memcpy(alg->base.cra_driver_name, "drbg_nopr_", 10);
-               pos = 10;
-       }
-       memcpy(alg->base.cra_driver_name + pos, core->cra_name,
-              strlen(core->cra_name));
-
-       alg->base.cra_priority = priority;
-       priority++;
-       /*
-        * If FIPS mode enabled, the selected DRBG shall have the
-        * highest cra_priority over other stdrng instances to ensure
-        * it is selected.
-        */
-       if (fips_enabled)
-               alg->base.cra_priority += 2000;
-
-       alg->base.cra_ctxsize   = sizeof(struct drbg_state);
-       alg->base.cra_module    = THIS_MODULE;
-       alg->base.cra_init      = drbg_kcapi_init;
-       alg->base.cra_exit      = drbg_kcapi_cleanup;
-       alg->generate           = drbg_kcapi_random;
-       alg->seed               = drbg_kcapi_seed;
-       alg->set_ent            = drbg_kcapi_set_entropy;
-       alg->seedsize           = 0;
-}
+static struct rng_alg drbg_algs[] = {
+       {
+               .base.cra_name          = "stdrng",
+               .base.cra_driver_name   = "drbg_pr_hmac_sha512",
+               .base.cra_priority      = 200,
+               .base.cra_ctxsize       = sizeof(struct drbg_state),
+               .base.cra_module        = THIS_MODULE,
+               .base.cra_init          = drbg_kcapi_init,
+               .set_ent                = drbg_kcapi_set_entropy,
+               .seed                   = drbg_kcapi_seed,
+               .generate               = drbg_kcapi_random,
+               .base.cra_exit          = drbg_kcapi_cleanup,
+       },
+       {
+               .base.cra_name          = "stdrng",
+               .base.cra_driver_name   = "drbg_nopr_hmac_sha512",
+               .base.cra_priority      = 201,
+               .base.cra_ctxsize       = sizeof(struct drbg_state),
+               .base.cra_module        = THIS_MODULE,
+               .base.cra_init          = drbg_kcapi_init,
+               .set_ent                = drbg_kcapi_set_entropy,
+               .seed                   = drbg_kcapi_seed,
+               .generate               = drbg_kcapi_random,
+               .base.cra_exit          = drbg_kcapi_cleanup,
+       },
+};
 
 static int __init drbg_init(void)
 {
-       unsigned int i = 0; /* pointer to drbg_algs */
-       unsigned int j = 0; /* pointer to drbg_cores */
        int ret;
 
        ret = drbg_healthcheck_sanity();
        if (ret)
                return ret;
 
-       if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) {
-               pr_info("DRBG: Cannot register all DRBG types"
-                       "(slots needed: %zu, slots available: %zu)\n",
-                       ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs));
-               return -EFAULT;
-       }
-
        /*
-        * each DRBG definition can be used with PR and without PR, thus
-        * we instantiate each DRBG in drbg_cores[] twice.
-        *
-        * As the order of placing them into the drbg_algs array matters
-        * (the later DRBGs receive a higher cra_priority) we register the
-        * prediction resistance DRBGs first as the should not be too
-        * interesting.
+        * In FIPS mode, boost the algorithm priorities to ensure that when
+        * users request "stdrng", they really get an algorithm from here.
         */
-       for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++)
-               drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1);
-       for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++)
-               drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0);
-       return crypto_register_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2));
+       if (fips_enabled) {
+               for (size_t i = 0; i < ARRAY_SIZE(drbg_algs); i++)
+                       drbg_algs[i].base.cra_priority += 2000;
+       }
+
+       return crypto_register_rngs(drbg_algs, ARRAY_SIZE(drbg_algs));
 }
 
 static void __exit drbg_exit(void)
 {
-       crypto_unregister_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2));
+       crypto_unregister_rngs(drbg_algs, ARRAY_SIZE(drbg_algs));
 }
 
 module_init(drbg_init);