[PATCH crypto] crypto: aesni - add wrapper for generic gcm(aes)

From: Sabrina Dubroca
Date: Wed Dec 13 2017 - 08:54:54 EST


When I added generic-gcm-aes I didn't add a wrapper like the one
provided for rfc4106(gcm(aes)). We need to add a cryptd wrapper to fall
back on in case the FPU is not available, otherwise we might corrupt the
FPU state.

Fixes: cce2ea8d90fe ("crypto: aesni - add generic gcm(aes)")
Reported-by: Ilya Lesokhin <ilyal@xxxxxxxxxxxx>
Signed-off-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
Reviewed-by: Stefano Brivio <sbrivio@xxxxxxxxxx>
---
arch/x86/crypto/aesni-intel_glue.c | 66 +++++++++++++++++++++++++++++++-------
1 file changed, 54 insertions(+), 12 deletions(-)

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 8981ed1eb7ad..a5ee78d723cd 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -690,8 +690,8 @@ static int common_rfc4106_set_key(struct crypto_aead *aead, const u8 *key,
rfc4106_set_hash_subkey(ctx->hash_subkey, key, key_len);
}

-static int rfc4106_set_key(struct crypto_aead *parent, const u8 *key,
- unsigned int key_len)
+static int gcmaes_wrapper_set_key(struct crypto_aead *parent, const u8 *key,
+ unsigned int key_len)
{
struct cryptd_aead **ctx = crypto_aead_ctx(parent);
struct cryptd_aead *cryptd_tfm = *ctx;
@@ -716,8 +716,8 @@ static int common_rfc4106_set_authsize(struct crypto_aead *aead,

/* 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 gcmaes_wrapper_set_authsize(struct crypto_aead *parent,
+ unsigned int authsize)
{
struct cryptd_aead **ctx = crypto_aead_ctx(parent);
struct cryptd_aead *cryptd_tfm = *ctx;
@@ -929,7 +929,7 @@ static int helper_rfc4106_decrypt(struct aead_request *req)
aes_ctx);
}

-static int rfc4106_encrypt(struct aead_request *req)
+static int gcmaes_wrapper_encrypt(struct aead_request *req)
{
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
struct cryptd_aead **ctx = crypto_aead_ctx(tfm);
@@ -945,7 +945,7 @@ static int rfc4106_encrypt(struct aead_request *req)
return crypto_aead_encrypt(req);
}

-static int rfc4106_decrypt(struct aead_request *req)
+static int gcmaes_wrapper_decrypt(struct aead_request *req)
{
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
struct cryptd_aead **ctx = crypto_aead_ctx(tfm);
@@ -1128,6 +1128,30 @@ static int generic_gcmaes_decrypt(struct aead_request *req)
aes_ctx);
}

+static int generic_gcmaes_init(struct crypto_aead *aead)
+{
+ struct cryptd_aead *cryptd_tfm;
+ struct cryptd_aead **ctx = crypto_aead_ctx(aead);
+
+ cryptd_tfm = cryptd_alloc_aead("__driver-generic-gcm-aes-aesni",
+ CRYPTO_ALG_INTERNAL,
+ CRYPTO_ALG_INTERNAL);
+ if (IS_ERR(cryptd_tfm))
+ return PTR_ERR(cryptd_tfm);
+
+ *ctx = cryptd_tfm;
+ crypto_aead_set_reqsize(aead, crypto_aead_reqsize(&cryptd_tfm->base));
+
+ return 0;
+}
+
+static void generic_gcmaes_exit(struct crypto_aead *aead)
+{
+ struct cryptd_aead **ctx = crypto_aead_ctx(aead);
+
+ cryptd_free_aead(*ctx);
+}
+
static struct aead_alg aesni_aead_algs[] = { {
.setkey = common_rfc4106_set_key,
.setauthsize = common_rfc4106_set_authsize,
@@ -1147,10 +1171,10 @@ static struct aead_alg aesni_aead_algs[] = { {
}, {
.init = rfc4106_init,
.exit = rfc4106_exit,
- .setkey = rfc4106_set_key,
- .setauthsize = rfc4106_set_authsize,
- .encrypt = rfc4106_encrypt,
- .decrypt = rfc4106_decrypt,
+ .setkey = gcmaes_wrapper_set_key,
+ .setauthsize = gcmaes_wrapper_set_authsize,
+ .encrypt = gcmaes_wrapper_encrypt,
+ .decrypt = gcmaes_wrapper_decrypt,
.ivsize = GCM_RFC4106_IV_SIZE,
.maxauthsize = 16,
.base = {
@@ -1169,14 +1193,32 @@ static struct aead_alg aesni_aead_algs[] = { {
.decrypt = generic_gcmaes_decrypt,
.ivsize = GCM_AES_IV_SIZE,
.maxauthsize = 16,
+ .base = {
+ .cra_name = "__generic-gcm-aes-aesni",
+ .cra_driver_name = "__driver-generic-gcm-aes-aesni",
+ .cra_priority = 0,
+ .cra_flags = CRYPTO_ALG_INTERNAL,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct generic_gcmaes_ctx),
+ .cra_alignmask = AESNI_ALIGN - 1,
+ .cra_module = THIS_MODULE,
+ },
+}, {
+ .init = generic_gcmaes_init,
+ .exit = generic_gcmaes_exit,
+ .setkey = gcmaes_wrapper_set_key,
+ .setauthsize = gcmaes_wrapper_set_authsize,
+ .encrypt = gcmaes_wrapper_encrypt,
+ .decrypt = gcmaes_wrapper_decrypt,
+ .ivsize = GCM_AES_IV_SIZE,
+ .maxauthsize = 16,
.base = {
.cra_name = "gcm(aes)",
.cra_driver_name = "generic-gcm-aesni",
.cra_priority = 400,
.cra_flags = CRYPTO_ALG_ASYNC,
.cra_blocksize = 1,
- .cra_ctxsize = sizeof(struct generic_gcmaes_ctx),
- .cra_alignmask = AESNI_ALIGN - 1,
+ .cra_ctxsize = sizeof(struct cryptd_aead *),
.cra_module = THIS_MODULE,
},
} };
--
2.15.1