1 files changed, 823 insertions, 0 deletions

diff --git a/crypto/gcm.c b/crypto/gcm.c
new file mode 100644
index 000000000000..e70afd0c73dd
--- /dev/null
+++ b/crypto/gcm.c
@@ -0,0 +1,823 @@
+/*
+ * GCM: Galois/Counter Mode.
+ *
+ * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <crypto/gf128mul.h>
+#include <crypto/internal/aead.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
+#include <linux/completion.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+struct gcm_instance_ctx {
+        struct crypto_skcipher_spawn ctr;
+};
+
+struct crypto_gcm_ctx {
+        struct crypto_ablkcipher *ctr;
+        struct gf128mul_4k *gf128;
+};
+
+struct crypto_rfc4106_ctx {
+        struct crypto_aead *child;
+        u8 nonce[4];
+};
+
+struct crypto_gcm_ghash_ctx {
+        u32 bytes;
+        u32 flags;
+        struct gf128mul_4k *gf128;
+        u8 buffer[16];
+};
+
+struct crypto_gcm_req_priv_ctx {
+        u8 auth_tag[16];
+        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_setkey_result {
+        int err;
+        struct completion completion;
+};
+
+static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
+        struct aead_request *req)
+{
+        unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
+
+        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;
+
+        if (err == -EINPROGRESS)
+                return;
+
+        result->err = err;
+        complete(&result->completion);
+}
+
+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_ablkcipher *ctr = ctx->ctr;
+        struct {
+                be128 hash;
+                u8 iv[8];
+
+                struct crypto_gcm_setkey_result result;
+
+                struct scatterlist sg[1];
+                struct ablkcipher_request req;
+        } *data;
+        int err;
+
+        crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
+        crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
+                                   CRYPTO_TFM_REQ_MASK);
+
+        err = crypto_ablkcipher_setkey(ctr, key, keylen);
+        if (err)
+                return err;
+
+        crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
+                                       CRYPTO_TFM_RES_MASK);
+
+        data = kzalloc(sizeof(*data) + crypto_ablkcipher_reqsize(ctr),
+                       GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        init_completion(&data->result.completion);
+        sg_init_one(data->sg, &data->hash, sizeof(data->hash));
+        ablkcipher_request_set_tfm(&data->req, ctr);
+        ablkcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
+                                                    CRYPTO_TFM_REQ_MAY_BACKLOG,
+                                        crypto_gcm_setkey_done,
+                                        &data->result);
+        ablkcipher_request_set_crypt(&data->req, data->sg, data->sg,
+                                     sizeof(data->hash), data->iv);
+
+        err = crypto_ablkcipher_encrypt(&data->req);
+        if (err == -EINPROGRESS || err == -EBUSY) {
+                err = wait_for_completion_interruptible(
+                        &data->result.completion);
+                if (!err)
+                        err = data->result.err;
+        }
+
+        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;
+
+out:
+        kfree(data);
+        return err;
+}
+
+static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
+                                  unsigned int authsize)
+{
+        switch (authsize) {
+        case 4:
+        case 8:
+        case 12:
+        case 13:
+        case 14:
+        case 15:
+        case 16:
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static void crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req,
+                                  struct aead_request *req,
+                                  unsigned int cryptlen)
+{
+        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);
+
+        memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
+        memcpy(req->iv + 12, &counter, 4);
+
+        sg_init_table(pctx->src, 2);
+        sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
+        scatterwalk_sg_chain(pctx->src, 2, req->src);
+
+        dst = pctx->src;
+        if (req->src != req->dst) {
+                sg_init_table(pctx->dst, 2);
+                sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
+                scatterwalk_sg_chain(pctx->dst, 2, req->dst);
+                dst = pctx->dst;
+        }
+
+        ablkcipher_request_set_tfm(ablk_req, ctx->ctr);
+        ablkcipher_request_set_crypt(ablk_req, pctx->src, dst,
+                                     cryptlen + sizeof(pctx->auth_tag),
+                                     req->iv);
+
+        crypto_gcm_ghash_init(ghash, flags, ctx->gf128);
+
+        crypto_gcm_ghash_update_sg(ghash, req->assoc, req->assoclen);
+        crypto_gcm_ghash_flush(ghash);
+}
+
+static int crypto_gcm_hash(struct aead_request *req)
+{
+        struct crypto_aead *aead = crypto_aead_reqtfm(req);
+        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;
+
+        crypto_gcm_ghash_update_sg(ghash, req->dst, req->cryptlen);
+        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 crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
+        struct ablkcipher_request *abreq = &pctx->abreq;
+        int err;
+
+        crypto_gcm_init_crypt(abreq, req, req->cryptlen);
+        ablkcipher_request_set_callback(abreq, aead_request_flags(req),
+                                        crypto_gcm_encrypt_done, req);
+
+        err = crypto_ablkcipher_encrypt(abreq);
+        if (err)
+                return err;
+
+        return crypto_gcm_hash(req);
+}
+
+static int crypto_gcm_verify(struct aead_request *req)
+{
+        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);
+        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)
+{
+        struct aead_request *req = areq->data;
+
+        if (!err)
+                err = crypto_gcm_verify(req);
+
+        aead_request_complete(req, 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;
+        unsigned int authsize = crypto_aead_authsize(aead);
+        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);
+
+        crypto_gcm_ghash_update_sg(ghash, req->src, cryptlen);
+
+        err = crypto_ablkcipher_decrypt(abreq);
+        if (err)
+                return err;
+
+        return crypto_gcm_verify(req);
+}
+
+static int crypto_gcm_init_tfm(struct crypto_tfm *tfm)
+{
+        struct crypto_instance *inst = (void *)tfm->__crt_alg;
+        struct gcm_instance_ctx *ictx = crypto_instance_ctx(inst);
+        struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
+        struct crypto_ablkcipher *ctr;
+        unsigned long align;
+        int err;
+
+        ctr = crypto_spawn_skcipher(&ictx->ctr);
+        err = PTR_ERR(ctr);
+        if (IS_ERR(ctr))
+                return err;
+
+        ctx->ctr = ctr;
+        ctx->gf128 = NULL;
+
+        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);
+
+        return 0;
+}
+
+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_ablkcipher(ctx->ctr);
+}
+
+static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
+                                                       const char *full_name,
+                                                       const char *ctr_name)
+{
+        struct crypto_attr_type *algt;
+        struct crypto_instance *inst;
+        struct crypto_alg *ctr;
+        struct gcm_instance_ctx *ctx;
+        int err;
+
+        algt = crypto_get_attr_type(tb);
+        err = PTR_ERR(algt);
+        if (IS_ERR(algt))
+                return ERR_PTR(err);
+
+        if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
+                return ERR_PTR(-EINVAL);
+
+        inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
+        if (!inst)
+                return ERR_PTR(-ENOMEM);
+
+        ctx = crypto_instance_ctx(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;
+
+        ctr = crypto_skcipher_spawn_alg(&ctx->ctr);
+
+        /* We only support 16-byte blocks. */
+        if (ctr->cra_ablkcipher.ivsize != 16)
+                goto out_put_ctr;
+
+        /* Not a stream cipher? */
+        err = -EINVAL;
+        if (ctr->cra_blocksize != 1)
+                goto out_put_ctr;
+
+        err = -ENAMETOOLONG;
+        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+                     "gcm_base(%s)", ctr->cra_driver_name) >=
+            CRYPTO_MAX_ALG_NAME)
+                goto out_put_ctr;
+
+        memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
+
+        inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
+        inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
+        inst->alg.cra_priority = ctr->cra_priority;
+        inst->alg.cra_blocksize = 1;
+        inst->alg.cra_alignmask = ctr->cra_alignmask | (__alignof__(u64) - 1);
+        inst->alg.cra_type = &crypto_aead_type;
+        inst->alg.cra_aead.ivsize = 16;
+        inst->alg.cra_aead.maxauthsize = 16;
+        inst->alg.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
+        inst->alg.cra_init = crypto_gcm_init_tfm;
+        inst->alg.cra_exit = crypto_gcm_exit_tfm;
+        inst->alg.cra_aead.setkey = crypto_gcm_setkey;
+        inst->alg.cra_aead.setauthsize = crypto_gcm_setauthsize;
+        inst->alg.cra_aead.encrypt = crypto_gcm_encrypt;
+        inst->alg.cra_aead.decrypt = crypto_gcm_decrypt;
+
+out:
+        return inst;
+
+out_put_ctr:
+        crypto_drop_skcipher(&ctx->ctr);
+err_free_inst:
+        kfree(inst);
+        inst = ERR_PTR(err);
+        goto out;
+}
+
+static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
+{
+        int err;
+        const char *cipher_name;
+        char ctr_name[CRYPTO_MAX_ALG_NAME];
+        char full_name[CRYPTO_MAX_ALG_NAME];
+
+        cipher_name = crypto_attr_alg_name(tb[1]);
+        err = PTR_ERR(cipher_name);
+        if (IS_ERR(cipher_name))
+                return ERR_PTR(err);
+
+        if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
+            CRYPTO_MAX_ALG_NAME)
+                return ERR_PTR(-ENAMETOOLONG);
+
+        if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >=
+            CRYPTO_MAX_ALG_NAME)
+                return ERR_PTR(-ENAMETOOLONG);
+
+        return crypto_gcm_alloc_common(tb, full_name, ctr_name);
+}
+
+static void crypto_gcm_free(struct crypto_instance *inst)
+{
+        struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
+
+        crypto_drop_skcipher(&ctx->ctr);
+        kfree(inst);
+}
+
+static struct crypto_template crypto_gcm_tmpl = {
+        .name = "gcm",
+        .alloc = crypto_gcm_alloc,
+        .free = crypto_gcm_free,
+        .module = THIS_MODULE,
+};
+
+static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb)
+{
+        int err;
+        const char *ctr_name;
+        char full_name[CRYPTO_MAX_ALG_NAME];
+
+        ctr_name = crypto_attr_alg_name(tb[1]);
+        err = PTR_ERR(ctr_name);
+        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)
+                return ERR_PTR(-ENAMETOOLONG);
+
+        return crypto_gcm_alloc_common(tb, full_name, ctr_name);
+}
+
+static struct crypto_template crypto_gcm_base_tmpl = {
+        .name = "gcm_base",
+        .alloc = crypto_gcm_base_alloc,
+        .free = crypto_gcm_free,
+        .module = THIS_MODULE,
+};
+
+static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
+                                 unsigned int keylen)
+{
+        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
+        struct crypto_aead *child = ctx->child;
+        int err;
+
+        if (keylen < 4)
+                return -EINVAL;
+
+        keylen -= 4;
+        memcpy(ctx->nonce, key + keylen, 4);
+
+        crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+        crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
+                                     CRYPTO_TFM_REQ_MASK);
+        err = crypto_aead_setkey(child, key, keylen);
+        crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
+                                      CRYPTO_TFM_RES_MASK);
+
+        return err;
+}
+
+static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
+                                      unsigned int authsize)
+{
+        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
+
+        switch (authsize) {
+        case 8:
+        case 12:
+        case 16:
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return crypto_aead_setauthsize(ctx->child, authsize);
+}
+
+static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
+{
+        struct aead_request *subreq = aead_request_ctx(req);
+        struct crypto_aead *aead = crypto_aead_reqtfm(req);
+        struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
+        struct crypto_aead *child = ctx->child;
+        u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
+                           crypto_aead_alignmask(child) + 1);
+
+        memcpy(iv, ctx->nonce, 4);
+        memcpy(iv + 4, req->iv, 8);
+
+        aead_request_set_tfm(subreq, child);
+        aead_request_set_callback(subreq, req->base.flags, req->base.complete,
+                                  req->base.data);
+        aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
+        aead_request_set_assoc(subreq, req->assoc, req->assoclen);
+
+        return subreq;
+}
+
+static int crypto_rfc4106_encrypt(struct aead_request *req)
+{
+        req = crypto_rfc4106_crypt(req);
+
+        return crypto_aead_encrypt(req);
+}
+
+static int crypto_rfc4106_decrypt(struct aead_request *req)
+{
+        req = crypto_rfc4106_crypt(req);
+
+        return crypto_aead_decrypt(req);
+}
+
+static int crypto_rfc4106_init_tfm(struct crypto_tfm *tfm)
+{
+        struct crypto_instance *inst = (void *)tfm->__crt_alg;
+        struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
+        struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm);
+        struct crypto_aead *aead;
+        unsigned long align;
+
+        aead = crypto_spawn_aead(spawn);
+        if (IS_ERR(aead))
+                return PTR_ERR(aead);
+
+        ctx->child = aead;
+
+        align = crypto_aead_alignmask(aead);
+        align &= ~(crypto_tfm_ctx_alignment() - 1);
+        tfm->crt_aead.reqsize = sizeof(struct aead_request) +
+                                ALIGN(crypto_aead_reqsize(aead),
+                                      crypto_tfm_ctx_alignment()) +
+                                align + 16;
+
+        return 0;
+}
+
+static void crypto_rfc4106_exit_tfm(struct crypto_tfm *tfm)
+{
+        struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm);
+
+        crypto_free_aead(ctx->child);
+}
+
+static struct crypto_instance *crypto_rfc4106_alloc(struct rtattr **tb)
+{
+        struct crypto_attr_type *algt;
+        struct crypto_instance *inst;
+        struct crypto_aead_spawn *spawn;
+        struct crypto_alg *alg;
+        const char *ccm_name;
+        int err;
+
+        algt = crypto_get_attr_type(tb);
+        err = PTR_ERR(algt);
+        if (IS_ERR(algt))
+                return ERR_PTR(err);
+
+        if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
+                return ERR_PTR(-EINVAL);
+
+        ccm_name = crypto_attr_alg_name(tb[1]);
+        err = PTR_ERR(ccm_name);
+        if (IS_ERR(ccm_name))
+                return ERR_PTR(err);
+
+        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+        if (!inst)
+                return ERR_PTR(-ENOMEM);
+
+        spawn = crypto_instance_ctx(inst);
+        crypto_set_aead_spawn(spawn, inst);
+        err = crypto_grab_aead(spawn, ccm_name, 0,
+                               crypto_requires_sync(algt->type, algt->mask));
+        if (err)
+                goto out_free_inst;
+
+        alg = crypto_aead_spawn_alg(spawn);
+
+        err = -EINVAL;
+
+        /* We only support 16-byte blocks. */
+        if (alg->cra_aead.ivsize != 16)
+                goto out_drop_alg;
+
+        /* Not a stream cipher? */
+        if (alg->cra_blocksize != 1)
+                goto out_drop_alg;
+
+        err = -ENAMETOOLONG;
+        if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
+                     "rfc4106(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
+            snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+                     "rfc4106(%s)", alg->cra_driver_name) >=
+            CRYPTO_MAX_ALG_NAME)
+                goto out_drop_alg;
+
+        inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
+        inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
+        inst->alg.cra_priority = alg->cra_priority;
+        inst->alg.cra_blocksize = 1;
+        inst->alg.cra_alignmask = alg->cra_alignmask;
+        inst->alg.cra_type = &crypto_nivaead_type;
+
+        inst->alg.cra_aead.ivsize = 8;
+        inst->alg.cra_aead.maxauthsize = 16;
+
+        inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
+
+        inst->alg.cra_init = crypto_rfc4106_init_tfm;
+        inst->alg.cra_exit = crypto_rfc4106_exit_tfm;
+
+        inst->alg.cra_aead.setkey = crypto_rfc4106_setkey;
+        inst->alg.cra_aead.setauthsize = crypto_rfc4106_setauthsize;
+        inst->alg.cra_aead.encrypt = crypto_rfc4106_encrypt;
+        inst->alg.cra_aead.decrypt = crypto_rfc4106_decrypt;
+
+        inst->alg.cra_aead.geniv = "seqiv";
+
+out:
+        return inst;
+
+out_drop_alg:
+        crypto_drop_aead(spawn);
+out_free_inst:
+        kfree(inst);
+        inst = ERR_PTR(err);
+        goto out;
+}
+
+static void crypto_rfc4106_free(struct crypto_instance *inst)
+{
+        crypto_drop_spawn(crypto_instance_ctx(inst));
+        kfree(inst);
+}
+
+static struct crypto_template crypto_rfc4106_tmpl = {
+        .name = "rfc4106",
+        .alloc = crypto_rfc4106_alloc,
+        .free = crypto_rfc4106_free,
+        .module = THIS_MODULE,
+};
+
+static int __init crypto_gcm_module_init(void)
+{
+        int err;
+
+        err = crypto_register_template(&crypto_gcm_base_tmpl);
+        if (err)
+                goto out;
+
+        err = crypto_register_template(&crypto_gcm_tmpl);
+        if (err)
+                goto out_undo_base;
+
+        err = crypto_register_template(&crypto_rfc4106_tmpl);
+        if (err)
+                goto out_undo_gcm;
+
+out:
+        return err;
+
+out_undo_gcm:
+        crypto_unregister_template(&crypto_gcm_tmpl);
+out_undo_base:
+        crypto_unregister_template(&crypto_gcm_base_tmpl);
+        goto out;
+}
+
+static void __exit crypto_gcm_module_exit(void)
+{
+        crypto_unregister_template(&crypto_rfc4106_tmpl);
+        crypto_unregister_template(&crypto_gcm_tmpl);
+        crypto_unregister_template(&crypto_gcm_base_tmpl);
+}
+
+module_init(crypto_gcm_module_init);
+module_exit(crypto_gcm_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Galois/Counter Mode");
+MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
+MODULE_ALIAS("gcm_base");
+MODULE_ALIAS("rfc4106");