On 4/28/25 12:04, Eric Biggers wrote:
From: Eric Biggers <[email protected]>

This user of SHA-256 does not support any other algorithm, so the
crypto_shash abstraction provides no value.  Just use the SHA-256
library API instead, which is much simpler and easier to use.

Signed-off-by: Eric Biggers <[email protected]>

Acked-by: John Johansen <[email protected]>

---

This patch is targeting the apparmor tree for 6.16.

  security/apparmor/Kconfig  |  3 +-
  security/apparmor/crypto.c | 85 ++++++--------------------------------
  2 files changed, 13 insertions(+), 75 deletions(-)

diff --git a/security/apparmor/Kconfig b/security/apparmor/Kconfig
index 64cc3044a42ce..1e3bd44643dac 100644
--- a/security/apparmor/Kconfig
+++ b/security/apparmor/Kconfig
@@ -57,12 +57,11 @@ config SECURITY_APPARMOR_INTROSPECT_POLICY
          cpu is paramount.
config SECURITY_APPARMOR_HASH
        bool "Enable introspection of sha256 hashes for loaded profiles"
        depends on SECURITY_APPARMOR_INTROSPECT_POLICY
-       select CRYPTO
-       select CRYPTO_SHA256
+       select CRYPTO_LIB_SHA256
        default y
        help
          This option selects whether introspection of loaded policy
          hashes is available to userspace via the apparmor
          filesystem. This option provides a light weight means of
diff --git a/security/apparmor/crypto.c b/security/apparmor/crypto.c
index aad486b2fca65..40e17e153f1e5 100644
--- a/security/apparmor/crypto.c
+++ b/security/apparmor/crypto.c
@@ -9,115 +9,54 @@
   * Fns to provide a checksum of policy that has been loaded this can be
   * compared to userspace policy compiles to check loaded policy is what
   * it should be.
   */
-#include <crypto/hash.h>
+#include <crypto/sha2.h>
#include "include/apparmor.h"
  #include "include/crypto.h"
-static unsigned int apparmor_hash_size;
-
-static struct crypto_shash *apparmor_tfm;
-
  unsigned int aa_hash_size(void)
  {
-       return apparmor_hash_size;
+       return SHA256_DIGEST_SIZE;
  }
char *aa_calc_hash(void *data, size_t len)
  {
-       SHASH_DESC_ON_STACK(desc, apparmor_tfm);
        char *hash;
-       int error;
-
-       if (!apparmor_tfm)
-               return NULL;
- hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
+       hash = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
        if (!hash)
                return ERR_PTR(-ENOMEM);
- desc->tfm = apparmor_tfm;
-
-       error = crypto_shash_init(desc);
-       if (error)
-               goto fail;
-       error = crypto_shash_update(desc, (u8 *) data, len);
-       if (error)
-               goto fail;
-       error = crypto_shash_final(desc, hash);
-       if (error)
-               goto fail;
-
+       sha256(data, len, hash);
        return hash;
-
-fail:
-       kfree(hash);
-
-       return ERR_PTR(error);
  }
int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start,
                         size_t len)
  {
-       SHASH_DESC_ON_STACK(desc, apparmor_tfm);
-       int error;
+       struct sha256_state state;
        __le32 le32_version = cpu_to_le32(version);
if (!aa_g_hash_policy)
                return 0;
- if (!apparmor_tfm)
-               return 0;
-
-       profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
+       profile->hash = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
        if (!profile->hash)
                return -ENOMEM;
- desc->tfm = apparmor_tfm;
-
-       error = crypto_shash_init(desc);
-       if (error)
-               goto fail;
-       error = crypto_shash_update(desc, (u8 *) &le32_version, 4);
-       if (error)
-               goto fail;
-       error = crypto_shash_update(desc, (u8 *) start, len);
-       if (error)
-               goto fail;
-       error = crypto_shash_final(desc, profile->hash);
-       if (error)
-               goto fail;
-
+       sha256_init(&state);
+       sha256_update(&state, (u8 *)&le32_version, 4);
+       sha256_update(&state, (u8 *)start, len);
+       sha256_final(&state, profile->hash);
        return 0;
-
-fail:
-       kfree(profile->hash);
-       profile->hash = NULL;
-
-       return error;
  }
static int __init init_profile_hash(void)
  {
-       struct crypto_shash *tfm;
-
-       if (!apparmor_initialized)
-               return 0;
-
-       tfm = crypto_alloc_shash("sha256", 0, 0);
-       if (IS_ERR(tfm)) {
-               int error = PTR_ERR(tfm);
-               AA_ERROR("failed to setup profile sha256 hashing: %d\n", error);
-               return error;
-       }
-       apparmor_tfm = tfm;
-       apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm);
-
-       aa_info_message("AppArmor sha256 policy hashing enabled");
-
+       if (apparmor_initialized)
+               aa_info_message("AppArmor sha256 policy hashing enabled");
        return 0;
  }
-
  late_initcall(init_profile_hash);

base-commit: 33035b665157558254b3c21c3f049fd728e72368


Reply via email to