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Diffstat (limited to 'crypto/gcm.c')
-rw-r--r--crypto/gcm.c68
1 files changed, 40 insertions, 28 deletions
diff --git a/crypto/gcm.c b/crypto/gcm.c
index 5681c7957b88..ed8a6261b346 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -36,6 +36,7 @@ struct crypto_gcm_ghash_ctx {
struct crypto_gcm_req_priv_ctx {
u8 auth_tag[16];
+ u8 iauth_tag[16];
u8 counter[16];
struct crypto_gcm_ghash_ctx ghash;
};
@@ -89,6 +90,9 @@ static void crypto_gcm_ghash_update_sg(struct crypto_gcm_ghash_ctx *ctx,
u8 *src;
int n;
+ if (!len)
+ return;
+
scatterwalk_start(&walk, sg);
while (len) {
@@ -211,9 +215,10 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
}
static int crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req,
- struct aead_request *req,
- void (*done)(struct crypto_async_request *,
- int))
+ struct aead_request *req,
+ unsigned int cryptlen,
+ void (*done)(struct crypto_async_request *,
+ int))
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
@@ -228,7 +233,7 @@ static int crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req,
ablkcipher_request_set_callback(ablk_req, aead_request_flags(req),
done, req);
ablkcipher_request_set_crypt(ablk_req, req->src, req->dst,
- req->cryptlen, counter);
+ cryptlen, counter);
err = crypto_gcm_encrypt_counter(aead, auth_tag, 0, req->iv);
if (err)
@@ -239,18 +244,16 @@ static int crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req,
crypto_gcm_ghash_init(ghash, flags, ctx->gf128);
- if (req->assoclen) {
- crypto_gcm_ghash_update_sg(ghash, req->assoc, req->assoclen);
- crypto_gcm_ghash_flush(ghash);
- }
+ crypto_gcm_ghash_update_sg(ghash, req->assoc, req->assoclen);
+ crypto_gcm_ghash_flush(ghash);
out:
return err;
}
-static void crypto_gcm_encrypt_done(struct crypto_async_request *areq, int err)
+static int crypto_gcm_hash(struct aead_request *req)
{
- struct aead_request *req = areq->data;
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_gcm_req_priv_ctx *pctx = aead_request_ctx(req);
u8 *auth_tag = pctx->auth_tag;
struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
@@ -259,18 +262,28 @@ static void crypto_gcm_encrypt_done(struct crypto_async_request *areq, int err)
crypto_gcm_ghash_final_xor(ghash, req->assoclen, req->cryptlen,
auth_tag);
+ scatterwalk_map_and_copy(auth_tag, req->dst, req->cryptlen,
+ crypto_aead_authsize(aead), 1);
+ return 0;
+}
+
+static void crypto_gcm_encrypt_done(struct crypto_async_request *areq, int err)
+{
+ struct aead_request *req = areq->data;
+
+ if (!err)
+ err = crypto_gcm_hash(req);
+
aead_request_complete(req, err);
}
static int crypto_gcm_encrypt(struct aead_request *req)
{
struct ablkcipher_request abreq;
- struct crypto_gcm_req_priv_ctx *pctx = aead_request_ctx(req);
- u8 *auth_tag = pctx->auth_tag;
- struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
int err = 0;
- err = crypto_gcm_init_crypt(&abreq, req, crypto_gcm_encrypt_done);
+ err = crypto_gcm_init_crypt(&abreq, req, req->cryptlen,
+ crypto_gcm_encrypt_done);
if (err)
return err;
@@ -278,14 +291,9 @@ static int crypto_gcm_encrypt(struct aead_request *req)
err = crypto_ablkcipher_encrypt(&abreq);
if (err)
return err;
-
- crypto_gcm_ghash_update_sg(ghash, req->dst, req->cryptlen);
}
- crypto_gcm_ghash_final_xor(ghash, req->assoclen, req->cryptlen,
- auth_tag);
-
- return err;
+ return crypto_gcm_hash(req);
}
static void crypto_gcm_decrypt_done(struct crypto_async_request *areq, int err)
@@ -296,25 +304,29 @@ static void crypto_gcm_decrypt_done(struct crypto_async_request *areq, int err)
static int crypto_gcm_decrypt(struct aead_request *req)
{
struct ablkcipher_request abreq;
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_gcm_req_priv_ctx *pctx = aead_request_ctx(req);
u8 *auth_tag = pctx->auth_tag;
+ u8 *iauth_tag = pctx->iauth_tag;
struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
- u8 tag[16];
+ unsigned int cryptlen = req->cryptlen;
+ unsigned int authsize = crypto_aead_authsize(aead);
int err;
- if (!req->cryptlen)
+ if (cryptlen < authsize)
return -EINVAL;
+ cryptlen -= authsize;
- memcpy(tag, auth_tag, 16);
- err = crypto_gcm_init_crypt(&abreq, req, crypto_gcm_decrypt_done);
+ err = crypto_gcm_init_crypt(&abreq, req, cryptlen,
+ crypto_gcm_decrypt_done);
if (err)
return err;
- crypto_gcm_ghash_update_sg(ghash, req->src, req->cryptlen);
- crypto_gcm_ghash_final_xor(ghash, req->assoclen, req->cryptlen,
- auth_tag);
+ crypto_gcm_ghash_update_sg(ghash, req->src, cryptlen);
+ crypto_gcm_ghash_final_xor(ghash, req->assoclen, cryptlen, auth_tag);
- if (memcmp(tag, auth_tag, 16))
+ scatterwalk_map_and_copy(iauth_tag, req->src, cryptlen, authsize, 0);
+ if (memcmp(iauth_tag, auth_tag, authsize))
return -EINVAL;
return crypto_ablkcipher_decrypt(&abreq);