crypto: aesni - make driver-gcm-aes-aesni helper a proper aead alg

Changed the __driver-gcm-aes-aesni to be a proper aead algorithm.
This required a valid setkey and setauthsize functions to be added and also
some changes to make sure that math context is not corrupted when the alg is
used directly.
Note that the __driver-gcm-aes-aesni should not be used directly by modules
that can use it in interrupt context as we don't have a good fallback mechanism
in this case.

Signed-off-by: Adrian Hoban <adrian.hoban@intel.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 110 insertions, 54 deletions

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 947c6bf52c33..6893f4947583 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -890,15 +890,12 @@ out_free_ablkcipher:
         return ret;
 }
 
-static int rfc4106_set_key(struct crypto_aead *parent, const u8 *key,
-                                                   unsigned int key_len)
+static int common_rfc4106_set_key(struct crypto_aead *aead, const u8 *key,
+                                  unsigned int key_len)
 {
         int ret = 0;
-        struct crypto_tfm *tfm = crypto_aead_tfm(parent);
-        struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(parent);
-        struct crypto_aead *cryptd_child = cryptd_aead_child(ctx->cryptd_tfm);
-        struct aesni_rfc4106_gcm_ctx *child_ctx =
-                                 aesni_rfc4106_gcm_ctx_get(cryptd_child);
+        struct crypto_tfm *tfm = crypto_aead_tfm(aead);
+        struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(aead);
         u8 *new_key_align, *new_key_mem = NULL;
 
         if (key_len < 4) {
@@ -943,20 +940,31 @@ static int rfc4106_set_key(struct crypto_aead *parent, const u8 *key,
                 goto exit;
         }
         ret = rfc4106_set_hash_subkey(ctx->hash_subkey, key, key_len);
-        memcpy(child_ctx, ctx, sizeof(*ctx));
 exit:
         kfree(new_key_mem);
         return ret;
 }
 
-/* This is the Integrity Check Value (aka the authentication tag length and can
- * be 8, 12 or 16 bytes long. */
-static int rfc4106_set_authsize(struct crypto_aead *parent,
-                                unsigned int authsize)
+static int rfc4106_set_key(struct crypto_aead *parent, const u8 *key,
+                           unsigned int key_len)
 {
         struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(parent);
-        struct crypto_aead *cryptd_child = cryptd_aead_child(ctx->cryptd_tfm);
+        struct crypto_aead *child = cryptd_aead_child(ctx->cryptd_tfm);
+        struct aesni_rfc4106_gcm_ctx *c_ctx = aesni_rfc4106_gcm_ctx_get(child);
+        struct cryptd_aead *cryptd_tfm = ctx->cryptd_tfm;
+        int ret;
 
+        ret = crypto_aead_setkey(child, key, key_len);
+        if (!ret) {
+                memcpy(ctx, c_ctx, sizeof(*ctx));
+                ctx->cryptd_tfm = cryptd_tfm;
+        }
+        return ret;
+}
+
+static int common_rfc4106_set_authsize(struct crypto_aead *aead,
+                                       unsigned int authsize)
+{
         switch (authsize) {
         case 8:
         case 12:
@@ -965,51 +973,23 @@ static int rfc4106_set_authsize(struct crypto_aead *parent,
         default:
                 return -EINVAL;
         }
-        crypto_aead_crt(parent)->authsize = authsize;
-        crypto_aead_crt(cryptd_child)->authsize = authsize;
+        crypto_aead_crt(aead)->authsize = authsize;
         return 0;
 }
 
-static int rfc4106_encrypt(struct aead_request *req)
-{
-        int ret;
-        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
-        struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(tfm);
-
-        if (!irq_fpu_usable()) {
-                struct aead_request *cryptd_req =
-                        (struct aead_request *) aead_request_ctx(req);
-                memcpy(cryptd_req, req, sizeof(*req));
-                aead_request_set_tfm(cryptd_req, &ctx->cryptd_tfm->base);
-                return crypto_aead_encrypt(cryptd_req);
-        } else {
-                struct crypto_aead *cryptd_child = cryptd_aead_child(ctx->cryptd_tfm);
-                kernel_fpu_begin();
-                ret = cryptd_child->base.crt_aead.encrypt(req);
-                kernel_fpu_end();
-                return ret;
-        }
-}
-
-static int rfc4106_decrypt(struct aead_request *req)
+/* This is the Integrity Check Value (aka the authentication tag length and can
+ * be 8, 12 or 16 bytes long. */
+static int rfc4106_set_authsize(struct crypto_aead *parent,
+                                unsigned int authsize)
 {
+        struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(parent);
+        struct crypto_aead *child = cryptd_aead_child(ctx->cryptd_tfm);
         int ret;
-        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
-        struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(tfm);
 
-        if (!irq_fpu_usable()) {
-                struct aead_request *cryptd_req =
-                        (struct aead_request *) aead_request_ctx(req);
-                memcpy(cryptd_req, req, sizeof(*req));
-                aead_request_set_tfm(cryptd_req, &ctx->cryptd_tfm->base);
-                return crypto_aead_decrypt(cryptd_req);
-        } else {
-                struct crypto_aead *cryptd_child = cryptd_aead_child(ctx->cryptd_tfm);
-                kernel_fpu_begin();
-                ret = cryptd_child->base.crt_aead.decrypt(req);
-                kernel_fpu_end();
-                return ret;
-        }
+        ret = crypto_aead_setauthsize(child, authsize);
+        if (!ret)
+                crypto_aead_crt(parent)->authsize = authsize;
+        return ret;
 }
 
 static int __driver_rfc4106_encrypt(struct aead_request *req)
@@ -1185,6 +1165,78 @@ static int __driver_rfc4106_decrypt(struct aead_request *req)
         }
         return retval;
 }
+
+static int rfc4106_encrypt(struct aead_request *req)
+{
+        int ret;
+        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
+        struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(tfm);
+
+        if (!irq_fpu_usable()) {
+                struct aead_request *cryptd_req =
+                        (struct aead_request *) aead_request_ctx(req);
+
+                memcpy(cryptd_req, req, sizeof(*req));
+                aead_request_set_tfm(cryptd_req, &ctx->cryptd_tfm->base);
+                ret = crypto_aead_encrypt(cryptd_req);
+        } else {
+                kernel_fpu_begin();
+                ret = __driver_rfc4106_encrypt(req);
+                kernel_fpu_end();
+        }
+        return ret;
+}
+
+static int rfc4106_decrypt(struct aead_request *req)
+{
+        int ret;
+        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
+        struct aesni_rfc4106_gcm_ctx *ctx = aesni_rfc4106_gcm_ctx_get(tfm);
+
+        if (!irq_fpu_usable()) {
+                struct aead_request *cryptd_req =
+                        (struct aead_request *) aead_request_ctx(req);
+
+                memcpy(cryptd_req, req, sizeof(*req));
+                aead_request_set_tfm(cryptd_req, &ctx->cryptd_tfm->base);
+                ret = crypto_aead_decrypt(cryptd_req);
+        } else {
+                kernel_fpu_begin();
+                ret = __driver_rfc4106_decrypt(req);
+                kernel_fpu_end();
+        }
+        return ret;
+}
+
+static int helper_rfc4106_encrypt(struct aead_request *req)
+{
+        int ret;
+
+        if (unlikely(!irq_fpu_usable())) {
+                WARN_ONCE(1, "__gcm-aes-aesni alg used in invalid context");
+                ret = -EINVAL;
+        } else {
+                kernel_fpu_begin();
+                ret = __driver_rfc4106_encrypt(req);
+                kernel_fpu_end();
+        }
+        return ret;
+}
+
+static int helper_rfc4106_decrypt(struct aead_request *req)
+{
+        int ret;
+
+        if (unlikely(!irq_fpu_usable())) {
+                WARN_ONCE(1, "__gcm-aes-aesni alg used in invalid context");
+                ret = -EINVAL;
+        } else {
+                kernel_fpu_begin();
+                ret = __driver_rfc4106_decrypt(req);
+                kernel_fpu_end();
+        }
+        return ret;
+}
 #endif
 
 static struct crypto_alg aesni_algs[] = { {
@@ -1366,8 +1418,12 @@ static struct crypto_alg aesni_algs[] = { {
         .cra_module             = THIS_MODULE,
         .cra_u = {
                 .aead = {
-                        .encrypt        = __driver_rfc4106_encrypt,
-                        .decrypt        = __driver_rfc4106_decrypt,
+                        .setkey         = common_rfc4106_set_key,
+                        .setauthsize    = common_rfc4106_set_authsize,
+                        .encrypt        = helper_rfc4106_encrypt,
+                        .decrypt        = helper_rfc4106_decrypt,
+                        .ivsize         = 8,
+                        .maxauthsize    = 16,
                 },
         },
 }, {