Merge branch 'agp-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[pandora-kernel.git] / crypto / gcm.c
index e70afd0..5fc3292 100644 (file)
 #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>
 
 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);