crypto: drbg - Remove always-enabled symbol CRYPTO_DRBG_HMAC

The kconfig symbol CRYPTO_DRBG_HMAC is always enabled when
CRYPTO_DRBG_MENU is enabled, and all checks for CRYPTO_DRBG_HMAC are in
code conditional on CRYPTO_DRBG_MENU.  Thus, the only purpose of the
CRYPTO_DRBG_HMAC symbol is to select CRYPTO_HMAC and CRYPTO_SHA512.

Move those two selections to CRYPTO_DRBG_MENU, remove the checks for
CRYPTO_DRBG_HMAC, and remove the CRYPTO_DRBG_HMAC symbol itself.

Note that this also fixes an issue where CRYPTO_HMAC and CRYPTO_SHA512
were unnecessarily being forced to built-in when CRYPTO_DRBG=m.

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

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 103d1f58cb7c21aa9dfcc9fe716cc1ebb5e767c7..34da01c153d6bb2a91c2cad4cc5ba0a6c0d2646d 100644 (file)
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1122,12 +1122,6 @@ menuconfig CRYPTO_DRBG_MENU
 
 if CRYPTO_DRBG_MENU
 
-config CRYPTO_DRBG_HMAC
-       bool
-       default y
-       select CRYPTO_HMAC
-       select CRYPTO_SHA512
-
 config CRYPTO_DRBG_HASH
        bool "Hash_DRBG"
        select CRYPTO_SHA256
@@ -1147,8 +1141,10 @@ config CRYPTO_DRBG_CTR
 config CRYPTO_DRBG
        tristate
        default CRYPTO_DRBG_MENU
-       select CRYPTO_RNG
+       select CRYPTO_HMAC
        select CRYPTO_JITTERENTROPY
+       select CRYPTO_RNG
+       select CRYPTO_SHA512
 
 endif  # if CRYPTO_DRBG_MENU
 

diff --git a/crypto/drbg.c b/crypto/drbg.c
index e3065fb9541b2eec94422169c58ccab14af9616d..f6bff275c31bb0c6c9ee6df5a59861a78ea78853 100644 (file)
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -161,7 +161,6 @@ static const struct drbg_core drbg_cores[] = {
                .backend_cra_name = "sha256",
        },
 #endif /* CONFIG_CRYPTO_DRBG_HASH */
-#ifdef CONFIG_CRYPTO_DRBG_HMAC
        {
                .flags = DRBG_HMAC | DRBG_STRENGTH256,
                .statelen = 48, /* block length of cipher */
@@ -181,7 +180,6 @@ static const struct drbg_core drbg_cores[] = {
                .cra_name = "hmac_sha512",
                .backend_cra_name = "hmac(sha512)",
        },
-#endif /* CONFIG_CRYPTO_DRBG_HMAC */
 };
 
 static int drbg_uninstantiate(struct drbg_state *drbg);
@@ -406,16 +404,13 @@ static const struct drbg_state_ops drbg_ctr_ops = {
  * HMAC DRBG callback functions
  ******************************************************************/
 
-#if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
 static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval,
                           const struct list_head *in);
 static void drbg_kcapi_hmacsetkey(struct drbg_state *drbg,
                                  const unsigned char *key);
 static int drbg_init_hash_kernel(struct drbg_state *drbg);
 static int drbg_fini_hash_kernel(struct drbg_state *drbg);
-#endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
 
-#ifdef CONFIG_CRYPTO_DRBG_HMAC
 #define CRYPTO_DRBG_HMAC_STRING "HMAC "
 MODULE_ALIAS_CRYPTO("drbg_pr_hmac_sha512");
 MODULE_ALIAS_CRYPTO("drbg_nopr_hmac_sha512");
@@ -527,7 +522,6 @@ static const struct drbg_state_ops drbg_hmac_ops = {
        .crypto_init    = drbg_init_hash_kernel,
        .crypto_fini    = drbg_fini_hash_kernel,
 };
-#endif /* CONFIG_CRYPTO_DRBG_HMAC */
 
 /******************************************************************
  * Hash DRBG callback functions
@@ -1046,11 +1040,9 @@ static inline int drbg_alloc_state(struct drbg_state *drbg)
        unsigned int sb_size = 0;
 
        switch (drbg->core->flags & DRBG_TYPE_MASK) {
-#ifdef CONFIG_CRYPTO_DRBG_HMAC
        case DRBG_HMAC:
                drbg->d_ops = &drbg_hmac_ops;
                break;
-#endif /* CONFIG_CRYPTO_DRBG_HMAC */
 #ifdef CONFIG_CRYPTO_DRBG_HASH
        case DRBG_HASH:
                drbg->d_ops = &drbg_hash_ops;
@@ -1431,7 +1423,6 @@ static void drbg_kcapi_set_entropy(struct crypto_rng *tfm,
  * Kernel crypto API cipher invocations requested by DRBG
  ***************************************************************/
 
-#if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC)
 struct sdesc {
        struct shash_desc shash;
 };
@@ -1491,7 +1482,6 @@ static int drbg_kcapi_hash(struct drbg_state *drbg, unsigned char *outval,
                crypto_shash_update(&sdesc->shash, input->buf, input->len);
        return crypto_shash_final(&sdesc->shash, outval);
 }
-#endif /* (CONFIG_CRYPTO_DRBG_HASH || CONFIG_CRYPTO_DRBG_HMAC) */
 
 #ifdef CONFIG_CRYPTO_DRBG_CTR
 static int drbg_fini_sym_kernel(struct drbg_state *drbg)
@@ -1757,9 +1747,7 @@ static inline int __init drbg_healthcheck_sanity(void)
 #ifdef CONFIG_CRYPTO_DRBG_HASH
        drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr);
 #endif
-#ifdef CONFIG_CRYPTO_DRBG_HMAC
        drbg_convert_tfm_core("drbg_nopr_hmac_sha512", &coreref, &pr);
-#endif
 
        drbg = kzalloc_obj(struct drbg_state);
        if (!drbg)
@@ -1887,9 +1875,6 @@ module_exit(drbg_exit);
 #ifndef CRYPTO_DRBG_HASH_STRING
 #define CRYPTO_DRBG_HASH_STRING ""
 #endif
-#ifndef CRYPTO_DRBG_HMAC_STRING
-#define CRYPTO_DRBG_HMAC_STRING ""
-#endif
 #ifndef CRYPTO_DRBG_CTR_STRING
 #define CRYPTO_DRBG_CTR_STRING ""
 #endif