2 files changed, 408 insertions, 174 deletions

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 0ae170e01051..5105cf15834f 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -157,7 +157,7 @@ config CRYPTO_GCM
 	tristate "GCM/GMAC support"
 	select CRYPTO_CTR
 	select CRYPTO_AEAD
-	select CRYPTO_GF128MUL
+	select CRYPTO_GHASH
 	help
 	  Support for Galois/Counter Mode (GCM) and Galois Message
 	  Authentication Code (GMAC). Required for IPSec.
diff --git a/crypto/gcm.c b/crypto/gcm.c
index e70afd0c73dd..5fc3292483ef 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -11,7 +11,10 @@
 #include <crypto/gf128mul.h>
 #include <crypto/internal/aead.h>
 #include <crypto/internal/skcipher.h>
+#include <crypto/internal/hash.h>
 #include <crypto/scatterwalk.h>
+#include <crypto/hash.h>
+#include "internal.h"
 #include <linux/completion.h>
 #include <linux/err.h>
 #include <linux/init.h>
@@ -21,11 +24,12 @@
 
 struct gcm_instance_ctx {
 	struct crypto_skcipher_spawn ctr;
+	struct crypto_ahash_spawn ghash;
 };
 
 struct crypto_gcm_ctx {
 	struct crypto_ablkcipher *ctr;
-	struct gf128mul_4k *gf128;
+	struct crypto_ahash *ghash;
 };
 
 struct crypto_rfc4106_ctx {
@@ -34,10 +38,9 @@ struct crypto_rfc4106_ctx {
 };
 
 struct crypto_gcm_ghash_ctx {
-	u32 bytes;
-	u32 flags;
-	struct gf128mul_4k *gf128;
-	u8 buffer[16];
+	unsigned int cryptlen;
+	struct scatterlist *src;
+	crypto_completion_t complete;
 };
 
 struct crypto_gcm_req_priv_ctx {
@@ -45,8 +48,11 @@ struct crypto_gcm_req_priv_ctx {
 	u8 iauth_tag[16];
 	struct scatterlist src[2];
 	struct scatterlist dst[2];
-	struct crypto_gcm_ghash_ctx ghash;
-	struct ablkcipher_request abreq;
+	struct crypto_gcm_ghash_ctx ghash_ctx;
+	union {
+		struct ahash_request ahreq;
+		struct ablkcipher_request abreq;
+	} u;
 };
 
 struct crypto_gcm_setkey_result {
@@ -54,6 +60,8 @@ struct crypto_gcm_setkey_result {
 	struct completion completion;
 };
 
+static void *gcm_zeroes;
+
 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
 	struct aead_request *req)
 {
@@ -62,113 +70,6 @@ static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
 	return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
 }
 
-static void crypto_gcm_ghash_init(struct crypto_gcm_ghash_ctx *ctx, u32 flags,
-				  struct gf128mul_4k *gf128)
-{
-	ctx->bytes = 0;
-	ctx->flags = flags;
-	ctx->gf128 = gf128;
-	memset(ctx->buffer, 0, 16);
-}
-
-static void crypto_gcm_ghash_update(struct crypto_gcm_ghash_ctx *ctx,
-				    const u8 *src, unsigned int srclen)
-{
-	u8 *dst = ctx->buffer;
-
-	if (ctx->bytes) {
-		int n = min(srclen, ctx->bytes);
-		u8 *pos = dst + (16 - ctx->bytes);
-
-		ctx->bytes -= n;
-		srclen -= n;
-
-		while (n--)
-			*pos++ ^= *src++;
-
-		if (!ctx->bytes)
-			gf128mul_4k_lle((be128 *)dst, ctx->gf128);
-	}
-
-	while (srclen >= 16) {
-		crypto_xor(dst, src, 16);
-		gf128mul_4k_lle((be128 *)dst, ctx->gf128);
-		src += 16;
-		srclen -= 16;
-	}
-
-	if (srclen) {
-		ctx->bytes = 16 - srclen;
-		while (srclen--)
-			*dst++ ^= *src++;
-	}
-}
-
-static void crypto_gcm_ghash_update_sg(struct crypto_gcm_ghash_ctx *ctx,
-				       struct scatterlist *sg, int len)
-{
-	struct scatter_walk walk;
-	u8 *src;
-	int n;
-
-	if (!len)
-		return;
-
-	scatterwalk_start(&walk, sg);
-
-	while (len) {
-		n = scatterwalk_clamp(&walk, len);
-
-		if (!n) {
-			scatterwalk_start(&walk, scatterwalk_sg_next(walk.sg));
-			n = scatterwalk_clamp(&walk, len);
-		}
-
-		src = scatterwalk_map(&walk, 0);
-
-		crypto_gcm_ghash_update(ctx, src, n);
-		len -= n;
-
-		scatterwalk_unmap(src, 0);
-		scatterwalk_advance(&walk, n);
-		scatterwalk_done(&walk, 0, len);
-		if (len)
-			crypto_yield(ctx->flags);
-	}
-}
-
-static void crypto_gcm_ghash_flush(struct crypto_gcm_ghash_ctx *ctx)
-{
-	u8 *dst = ctx->buffer;
-
-	if (ctx->bytes) {
-		u8 *tmp = dst + (16 - ctx->bytes);
-
-		while (ctx->bytes--)
-			*tmp++ ^= 0;
-
-		gf128mul_4k_lle((be128 *)dst, ctx->gf128);
-	}
-
-	ctx->bytes = 0;
-}
-
-static void crypto_gcm_ghash_final_xor(struct crypto_gcm_ghash_ctx *ctx,
-				       unsigned int authlen,
-				       unsigned int cryptlen, u8 *dst)
-{
-	u8 *buf = ctx->buffer;
-	u128 lengths;
-
-	lengths.a = cpu_to_be64(authlen * 8);
-	lengths.b = cpu_to_be64(cryptlen * 8);
-
-	crypto_gcm_ghash_flush(ctx);
-	crypto_xor(buf, (u8 *)&lengths, 16);
-	gf128mul_4k_lle((be128 *)buf, ctx->gf128);
-	crypto_xor(dst, buf, 16);
-}
-
 static void crypto_gcm_setkey_done(struct crypto_async_request *req, int err)
 {
 	struct crypto_gcm_setkey_result *result = req->data;
@@ -184,6 +85,7 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 			     unsigned int keylen)
 {
 	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
+	struct crypto_ahash *ghash = ctx->ghash;
 	struct crypto_ablkcipher *ctr = ctx->ctr;
 	struct {
 		be128 hash;
@@ -233,13 +135,12 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 	if (err)
 		goto out;
 
-	if (ctx->gf128 != NULL)
-		gf128mul_free_4k(ctx->gf128);
-
-	ctx->gf128 = gf128mul_init_4k_lle(&data->hash);
-
-	if (ctx->gf128 == NULL)
-		err = -ENOMEM;
+	crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
+	crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
+			       CRYPTO_TFM_REQ_MASK);
+	err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
+	crypto_aead_set_flags(aead, crypto_ahash_get_flags(ghash) &
+			      CRYPTO_TFM_RES_MASK);
 
 out:
 	kfree(data);
@@ -272,8 +173,6 @@ static void crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req,
 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
 	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
-	u32 flags = req->base.tfm->crt_flags;
-	struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
 	struct scatterlist *dst;
 	__be32 counter = cpu_to_be32(1);
 
@@ -296,108 +195,398 @@ static void crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req,
 	ablkcipher_request_set_crypt(ablk_req, pctx->src, dst,
 				     cryptlen + sizeof(pctx->auth_tag),
 				     req->iv);
+}
+
+static inline unsigned int gcm_remain(unsigned int len)
+{
+	len &= 0xfU;
+	return len ? 16 - len : 0;
+}
+
+static void gcm_hash_len_done(struct crypto_async_request *areq, int err);
+static void gcm_hash_final_done(struct crypto_async_request *areq, int err);
 
-	crypto_gcm_ghash_init(ghash, flags, ctx->gf128);
+static int gcm_hash_update(struct aead_request *req,
+			   struct crypto_gcm_req_priv_ctx *pctx,
+			   crypto_completion_t complete,
+			   struct scatterlist *src,
+			   unsigned int len)
+{
+	struct ahash_request *ahreq = &pctx->u.ahreq;
 
-	crypto_gcm_ghash_update_sg(ghash, req->assoc, req->assoclen);
-	crypto_gcm_ghash_flush(ghash);
+	ahash_request_set_callback(ahreq, aead_request_flags(req),
+				   complete, req);
+	ahash_request_set_crypt(ahreq, src, NULL, len);
+
+	return crypto_ahash_update(ahreq);
 }
 
-static int crypto_gcm_hash(struct aead_request *req)
+static int gcm_hash_remain(struct aead_request *req,
+			   struct crypto_gcm_req_priv_ctx *pctx,
+			   unsigned int remain,
+			   crypto_completion_t complete)
 {
-	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct ahash_request *ahreq = &pctx->u.ahreq;
+
+	ahash_request_set_callback(ahreq, aead_request_flags(req),
+				   complete, req);
+	sg_init_one(pctx->src, gcm_zeroes, remain);
+	ahash_request_set_crypt(ahreq, pctx->src, NULL, remain);
+
+	return crypto_ahash_update(ahreq);
+}
+
+static int gcm_hash_len(struct aead_request *req,
+			struct crypto_gcm_req_priv_ctx *pctx)
+{
+	struct ahash_request *ahreq = &pctx->u.ahreq;
+	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
+	u128 lengths;
+
+	lengths.a = cpu_to_be64(req->assoclen * 8);
+	lengths.b = cpu_to_be64(gctx->cryptlen * 8);
+	memcpy(pctx->iauth_tag, &lengths, 16);
+	sg_init_one(pctx->src, pctx->iauth_tag, 16);
+	ahash_request_set_callback(ahreq, aead_request_flags(req),
+				   gcm_hash_len_done, req);
+	ahash_request_set_crypt(ahreq, pctx->src,
+				NULL, sizeof(lengths));
+
+	return crypto_ahash_update(ahreq);
+}
+
+static int gcm_hash_final(struct aead_request *req,
+			  struct crypto_gcm_req_priv_ctx *pctx)
+{
+	struct ahash_request *ahreq = &pctx->u.ahreq;
+
+	ahash_request_set_callback(ahreq, aead_request_flags(req),
+				   gcm_hash_final_done, req);
+	ahash_request_set_crypt(ahreq, NULL, pctx->iauth_tag, 0);
+
+	return crypto_ahash_final(ahreq);
+}
+
+static void gcm_hash_final_done(struct crypto_async_request *areq,
+				int err)
+{
+	struct aead_request *req = areq->data;
 	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
-	u8 *auth_tag = pctx->auth_tag;
-	struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
+	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
+
+	if (!err)
+		crypto_xor(pctx->auth_tag, pctx->iauth_tag, 16);
 
-	crypto_gcm_ghash_update_sg(ghash, req->dst, req->cryptlen);
-	crypto_gcm_ghash_final_xor(ghash, req->assoclen, req->cryptlen,
-				   auth_tag);
+	gctx->complete(areq, err);
+}
+
+static void gcm_hash_len_done(struct crypto_async_request *areq,
+			      int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+
+	if (!err) {
+		err = gcm_hash_final(req, pctx);
+		if (err == -EINPROGRESS || err == -EBUSY)
+			return;
+	}
+
+	gcm_hash_final_done(areq, err);
+}
+
+static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq,
+				       int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+
+	if (!err) {
+		err = gcm_hash_len(req, pctx);
+		if (err == -EINPROGRESS || err == -EBUSY)
+			return;
+	}
+
+	gcm_hash_len_done(areq, err);
+}
+
+static void gcm_hash_crypt_done(struct crypto_async_request *areq,
+				int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
+	unsigned int remain;
+
+	if (!err) {
+		remain = gcm_remain(gctx->cryptlen);
+		BUG_ON(!remain);
+		err = gcm_hash_remain(req, pctx, remain,
+				      gcm_hash_crypt_remain_done);
+		if (err == -EINPROGRESS || err == -EBUSY)
+			return;
+	}
+
+	gcm_hash_crypt_remain_done(areq, err);
+}
+
+static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq,
+					   int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
+	crypto_completion_t complete;
+	unsigned int remain = 0;
+
+	if (!err && gctx->cryptlen) {
+		remain = gcm_remain(gctx->cryptlen);
+		complete = remain ? gcm_hash_crypt_done :
+			gcm_hash_crypt_remain_done;
+		err = gcm_hash_update(req, pctx, complete,
+				      gctx->src, gctx->cryptlen);
+		if (err == -EINPROGRESS || err == -EBUSY)
+			return;
+	}
+
+	if (remain)
+		gcm_hash_crypt_done(areq, err);
+	else
+		gcm_hash_crypt_remain_done(areq, err);
+}
+
+static void gcm_hash_assoc_done(struct crypto_async_request *areq,
+				int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+	unsigned int remain;
+
+	if (!err) {
+		remain = gcm_remain(req->assoclen);
+		BUG_ON(!remain);
+		err = gcm_hash_remain(req, pctx, remain,
+				      gcm_hash_assoc_remain_done);
+		if (err == -EINPROGRESS || err == -EBUSY)
+			return;
+	}
+
+	gcm_hash_assoc_remain_done(areq, err);
+}
+
+static void gcm_hash_init_done(struct crypto_async_request *areq,
+			       int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+	crypto_completion_t complete;
+	unsigned int remain = 0;
+
+	if (!err && req->assoclen) {
+		remain = gcm_remain(req->assoclen);
+		complete = remain ? gcm_hash_assoc_done :
+			gcm_hash_assoc_remain_done;
+		err = gcm_hash_update(req, pctx, complete,
+				      req->assoc, req->assoclen);
+		if (err == -EINPROGRESS || err == -EBUSY)
+			return;
+	}
+
+	if (remain)
+		gcm_hash_assoc_done(areq, err);
+	else
+		gcm_hash_assoc_remain_done(areq, err);
+}
+
+static int gcm_hash(struct aead_request *req,
+		    struct crypto_gcm_req_priv_ctx *pctx)
+{
+	struct ahash_request *ahreq = &pctx->u.ahreq;
+	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
+	struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	unsigned int remain;
+	crypto_completion_t complete;
+	int err;
+
+	ahash_request_set_tfm(ahreq, ctx->ghash);
+
+	ahash_request_set_callback(ahreq, aead_request_flags(req),
+				   gcm_hash_init_done, req);
+	err = crypto_ahash_init(ahreq);
+	if (err)
+		return err;
+	remain = gcm_remain(req->assoclen);
+	complete = remain ? gcm_hash_assoc_done : gcm_hash_assoc_remain_done;
+	err = gcm_hash_update(req, pctx, complete, req->assoc, req->assoclen);
+	if (err)
+		return err;
+	if (remain) {
+		err = gcm_hash_remain(req, pctx, remain,
+				      gcm_hash_assoc_remain_done);
+		if (err)
+			return err;
+	}
+	remain = gcm_remain(gctx->cryptlen);
+	complete = remain ? gcm_hash_crypt_done : gcm_hash_crypt_remain_done;
+	err = gcm_hash_update(req, pctx, complete, gctx->src, gctx->cryptlen);
+	if (err)
+		return err;
+	if (remain) {
+		err = gcm_hash_remain(req, pctx, remain,
+				      gcm_hash_crypt_remain_done);
+		if (err)
+			return err;
+	}
+	err = gcm_hash_len(req, pctx);
+	if (err)
+		return err;
+	err = gcm_hash_final(req, pctx);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static void gcm_enc_copy_hash(struct aead_request *req,
+			      struct crypto_gcm_req_priv_ctx *pctx)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	u8 *auth_tag = pctx->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)
+static void gcm_enc_hash_done(struct crypto_async_request *areq,
+				     int err)
 {
 	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 
 	if (!err)
-		err = crypto_gcm_hash(req);
+		gcm_enc_copy_hash(req, pctx);
 
 	aead_request_complete(req, err);
 }
 
+static void gcm_encrypt_done(struct crypto_async_request *areq,
+				     int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+
+	if (!err) {
+		err = gcm_hash(req, pctx);
+		if (err == -EINPROGRESS || err == -EBUSY)
+			return;
+	}
+
+	gcm_enc_hash_done(areq, err);
+}
+
 static int crypto_gcm_encrypt(struct aead_request *req)
 {
 	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
-	struct ablkcipher_request *abreq = &pctx->abreq;
+	struct ablkcipher_request *abreq = &pctx->u.abreq;
+	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 	int err;
 
 	crypto_gcm_init_crypt(abreq, req, req->cryptlen);
 	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
-					crypto_gcm_encrypt_done, req);
+					gcm_encrypt_done, req);
+
+	gctx->src = req->dst;
+	gctx->cryptlen = req->cryptlen;
+	gctx->complete = gcm_enc_hash_done;
 
 	err = crypto_ablkcipher_encrypt(abreq);
 	if (err)
 		return err;
 
-	return crypto_gcm_hash(req);
+	err = gcm_hash(req, pctx);
+	if (err)
+		return err;
+
+	crypto_xor(pctx->auth_tag, pctx->iauth_tag, 16);
+	gcm_enc_copy_hash(req, pctx);
+
+	return 0;
 }
 
-static int crypto_gcm_verify(struct aead_request *req)
+static int crypto_gcm_verify(struct aead_request *req,
+			     struct crypto_gcm_req_priv_ctx *pctx)
 {
 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
-	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
-	struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
 	u8 *auth_tag = pctx->auth_tag;
 	u8 *iauth_tag = pctx->iauth_tag;
 	unsigned int authsize = crypto_aead_authsize(aead);
 	unsigned int cryptlen = req->cryptlen - authsize;
 
-	crypto_gcm_ghash_final_xor(ghash, req->assoclen, cryptlen, auth_tag);
-
-	authsize = crypto_aead_authsize(aead);
+	crypto_xor(auth_tag, iauth_tag, 16);
 	scatterwalk_map_and_copy(iauth_tag, req->src, cryptlen, authsize, 0);
 	return memcmp(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
 }
 
-static void crypto_gcm_decrypt_done(struct crypto_async_request *areq, int err)
+static void gcm_decrypt_done(struct crypto_async_request *areq, int err)
 {
 	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
 
 	if (!err)
-		err = crypto_gcm_verify(req);
+		err = crypto_gcm_verify(req, pctx);
 
 	aead_request_complete(req, err);
 }
 
+static void gcm_dec_hash_done(struct crypto_async_request *areq, int err)
+{
+	struct aead_request *req = areq->data;
+	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+	struct ablkcipher_request *abreq = &pctx->u.abreq;
+	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
+
+	if (!err) {
+		ablkcipher_request_set_callback(abreq, aead_request_flags(req),
+						gcm_decrypt_done, req);
+		crypto_gcm_init_crypt(abreq, req, gctx->cryptlen);
+		err = crypto_ablkcipher_decrypt(abreq);
+		if (err == -EINPROGRESS || err == -EBUSY)
+			return;
+	}
+
+	gcm_decrypt_done(areq, err);
+}
+
 static int crypto_gcm_decrypt(struct aead_request *req)
 {
 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
-	struct ablkcipher_request *abreq = &pctx->abreq;
-	struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
-	unsigned int cryptlen = req->cryptlen;
+	struct ablkcipher_request *abreq = &pctx->u.abreq;
+	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
 	unsigned int authsize = crypto_aead_authsize(aead);
+	unsigned int cryptlen = req->cryptlen;
 	int err;
 
 	if (cryptlen < authsize)
 		return -EINVAL;
 	cryptlen -= authsize;
 
-	crypto_gcm_init_crypt(abreq, req, cryptlen);
-	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
-					crypto_gcm_decrypt_done, req);
+	gctx->src = req->src;
+	gctx->cryptlen = cryptlen;
+	gctx->complete = gcm_dec_hash_done;
 
-	crypto_gcm_ghash_update_sg(ghash, req->src, cryptlen);
+	err = gcm_hash(req, pctx);
+	if (err)
+		return err;
 
+	ablkcipher_request_set_callback(abreq, aead_request_flags(req),
+					gcm_decrypt_done, req);
+	crypto_gcm_init_crypt(abreq, req, cryptlen);
 	err = crypto_ablkcipher_decrypt(abreq);
 	if (err)
 		return err;
 
-	return crypto_gcm_verify(req);
+	return crypto_gcm_verify(req, pctx);
 }
 
 static int crypto_gcm_init_tfm(struct crypto_tfm *tfm)
@@ -406,43 +595,56 @@ static int crypto_gcm_init_tfm(struct crypto_tfm *tfm)
 	struct gcm_instance_ctx *ictx = crypto_instance_ctx(inst);
 	struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
 	struct crypto_ablkcipher *ctr;
+	struct crypto_ahash *ghash;
 	unsigned long align;
 	int err;
 
+	ghash = crypto_spawn_ahash(&ictx->ghash);
+	if (IS_ERR(ghash))
+		return PTR_ERR(ghash);
+
 	ctr = crypto_spawn_skcipher(&ictx->ctr);
 	err = PTR_ERR(ctr);
 	if (IS_ERR(ctr))
-		return err;
+		goto err_free_hash;
 
 	ctx->ctr = ctr;
-	ctx->gf128 = NULL;
+	ctx->ghash = ghash;
 
 	align = crypto_tfm_alg_alignmask(tfm);
 	align &= ~(crypto_tfm_ctx_alignment() - 1);
 	tfm->crt_aead.reqsize = align +
-				sizeof(struct crypto_gcm_req_priv_ctx) +
-				crypto_ablkcipher_reqsize(ctr);
+		offsetof(struct crypto_gcm_req_priv_ctx, u) +
+		max(sizeof(struct ablkcipher_request) +
+		    crypto_ablkcipher_reqsize(ctr),
+		    sizeof(struct ahash_request) +
+		    crypto_ahash_reqsize(ghash));
 
 	return 0;
+
+err_free_hash:
+	crypto_free_ahash(ghash);
+	return err;
 }
 
 static void crypto_gcm_exit_tfm(struct crypto_tfm *tfm)
 {
 	struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
 
-	if (ctx->gf128 != NULL)
-		gf128mul_free_4k(ctx->gf128);
-
+	crypto_free_ahash(ctx->ghash);
 	crypto_free_ablkcipher(ctx->ctr);
 }
 
 static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
 						       const char *full_name,
-						       const char *ctr_name)
+						       const char *ctr_name,
+						       const char *ghash_name)
 {
 	struct crypto_attr_type *algt;
 	struct crypto_instance *inst;
 	struct crypto_alg *ctr;
+	struct crypto_alg *ghash_alg;
+	struct ahash_alg *ghash_ahash_alg;
 	struct gcm_instance_ctx *ctx;
 	int err;
 
@@ -454,17 +656,31 @@ static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 		return ERR_PTR(-EINVAL);
 
+	ghash_alg = crypto_find_alg(ghash_name, &crypto_ahash_type,
+				    CRYPTO_ALG_TYPE_HASH,
+				    CRYPTO_ALG_TYPE_AHASH_MASK);
+	err = PTR_ERR(ghash_alg);
+	if (IS_ERR(ghash_alg))
+		return ERR_PTR(err);
+
+	err = -ENOMEM;
 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 	if (!inst)
-		return ERR_PTR(-ENOMEM);
+		goto out_put_ghash;
 
 	ctx = crypto_instance_ctx(inst);
+	ghash_ahash_alg = container_of(ghash_alg, struct ahash_alg, halg.base);
+	err = crypto_init_ahash_spawn(&ctx->ghash, &ghash_ahash_alg->halg,
+				      inst);
+	if (err)
+		goto err_free_inst;
+
 	crypto_set_skcipher_spawn(&ctx->ctr, inst);
 	err = crypto_grab_skcipher(&ctx->ctr, ctr_name, 0,
 				   crypto_requires_sync(algt->type,
 							algt->mask));
 	if (err)
-		goto err_free_inst;
+		goto err_drop_ghash;
 
 	ctr = crypto_skcipher_spawn_alg(&ctx->ctr);
 
@@ -479,7 +695,8 @@ static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
 
 	err = -ENAMETOOLONG;
 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
-		     "gcm_base(%s)", ctr->cra_driver_name) >=
+		     "gcm_base(%s,%s)", ctr->cra_driver_name,
+		     ghash_alg->cra_driver_name) >=
 	    CRYPTO_MAX_ALG_NAME)
 		goto out_put_ctr;
 
@@ -502,12 +719,16 @@ static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
 	inst->alg.cra_aead.decrypt = crypto_gcm_decrypt;
 
 out:
+	crypto_mod_put(ghash_alg);
 	return inst;
 
 out_put_ctr:
 	crypto_drop_skcipher(&ctx->ctr);
+err_drop_ghash:
+	crypto_drop_ahash(&ctx->ghash);
 err_free_inst:
 	kfree(inst);
+out_put_ghash:
 	inst = ERR_PTR(err);
 	goto out;
 }
@@ -532,7 +753,7 @@ static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
 	    CRYPTO_MAX_ALG_NAME)
 		return ERR_PTR(-ENAMETOOLONG);
 
-	return crypto_gcm_alloc_common(tb, full_name, ctr_name);
+	return crypto_gcm_alloc_common(tb, full_name, ctr_name, "ghash");
 }
 
 static void crypto_gcm_free(struct crypto_instance *inst)
@@ -540,6 +761,7 @@ static void crypto_gcm_free(struct crypto_instance *inst)
 	struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
 
 	crypto_drop_skcipher(&ctx->ctr);
+	crypto_drop_ahash(&ctx->ghash);
 	kfree(inst);
 }
 
@@ -554,6 +776,7 @@ static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb)
 {
 	int err;
 	const char *ctr_name;
+	const char *ghash_name;
 	char full_name[CRYPTO_MAX_ALG_NAME];
 
 	ctr_name = crypto_attr_alg_name(tb[1]);
@@ -561,11 +784,16 @@ static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb)
 	if (IS_ERR(ctr_name))
 		return ERR_PTR(err);
 
-	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s)",
-		     ctr_name) >= CRYPTO_MAX_ALG_NAME)
+	ghash_name = crypto_attr_alg_name(tb[2]);
+	err = PTR_ERR(ghash_name);
+	if (IS_ERR(ghash_name))
+		return ERR_PTR(err);
+
+	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s,%s)",
+		     ctr_name, ghash_name) >= CRYPTO_MAX_ALG_NAME)
 		return ERR_PTR(-ENAMETOOLONG);
 
-	return crypto_gcm_alloc_common(tb, full_name, ctr_name);
+	return crypto_gcm_alloc_common(tb, full_name, ctr_name, ghash_name);
 }
 
 static struct crypto_template crypto_gcm_base_tmpl = {
@@ -784,6 +1012,10 @@ static int __init crypto_gcm_module_init(void)
 {
 	int err;
 
+	gcm_zeroes = kzalloc(16, GFP_KERNEL);
+	if (!gcm_zeroes)
+		return -ENOMEM;
+
 	err = crypto_register_template(&crypto_gcm_base_tmpl);
 	if (err)
 		goto out;
@@ -796,18 +1028,20 @@ static int __init crypto_gcm_module_init(void)
 	if (err)
 		goto out_undo_gcm;
 
-out:
-	return err;
+	return 0;
 
 out_undo_gcm:
 	crypto_unregister_template(&crypto_gcm_tmpl);
 out_undo_base:
 	crypto_unregister_template(&crypto_gcm_base_tmpl);
-	goto out;
+out:
+	kfree(gcm_zeroes);
+	return err;
 }
 
 static void __exit crypto_gcm_module_exit(void)
 {
+	kfree(gcm_zeroes);
 	crypto_unregister_template(&crypto_rfc4106_tmpl);
 	crypto_unregister_template(&crypto_gcm_tmpl);
 	crypto_unregister_template(&crypto_gcm_base_tmpl);