// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * CCM: Counter with CBC-MAC
 *
 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
 */

#include <crypto/internal/aead.h>
#include <crypto/internal/cipher.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <crypto/utils.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>

struct ccm_instance_ctx {
        struct crypto_skcipher_spawn ctr;
        struct crypto_ahash_spawn mac;
};

struct crypto_ccm_ctx {
        struct crypto_ahash *mac;
        struct crypto_skcipher *ctr;
};

struct crypto_rfc4309_ctx {
        struct crypto_aead *child;
        u8 nonce[3];
};

struct crypto_rfc4309_req_ctx {
        struct scatterlist src[3];
        struct scatterlist dst[3];
        struct aead_request subreq;
};

struct crypto_ccm_req_priv_ctx {
        u8 odata[16];
        u8 idata[16];
        u8 auth_tag[16];
        u32 flags;
        struct scatterlist src[3];
        struct scatterlist dst[3];
        union {
                struct ahash_request ahreq;
                struct skcipher_request skreq;
        };
};

struct cbcmac_tfm_ctx {
        struct crypto_cipher *child;
};

static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_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 int set_msg_len(u8 *block, unsigned int msglen, int csize)
{
        __be32 data;

        memset(block, 0, csize);
        block += csize;

        if (csize >= 4)
                csize = 4;
        else if (msglen > (1 << (8 * csize)))
                return -EOVERFLOW;

        data = cpu_to_be32(msglen);
        memcpy(block - csize, (u8 *)&data + 4 - csize, csize);

        return 0;
}

static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
                             unsigned int keylen)
{
        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
        struct crypto_skcipher *ctr = ctx->ctr;
        struct crypto_ahash *mac = ctx->mac;
        int err;

        crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
        crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
                                       CRYPTO_TFM_REQ_MASK);
        err = crypto_skcipher_setkey(ctr, key, keylen);
        if (err)
                return err;

        crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
        crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
                                    CRYPTO_TFM_REQ_MASK);
        return crypto_ahash_setkey(mac, key, keylen);
}

static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
                                  unsigned int authsize)
{
        switch (authsize) {
        case 4:
        case 6:
        case 8:
        case 10:
        case 12:
        case 14:
        case 16:
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int format_input(u8 *info, struct aead_request *req,
                        unsigned int cryptlen)
{
        struct crypto_aead *aead = crypto_aead_reqtfm(req);
        unsigned int lp = req->iv[0];
        unsigned int l = lp + 1;
        unsigned int m;

        m = crypto_aead_authsize(aead);

        memcpy(info, req->iv, 16);

        /* format control info per RFC 3610 and
         * NIST Special Publication 800-38C
         */
        *info |= (8 * ((m - 2) / 2));
        if (req->assoclen)
                *info |= 64;

        return set_msg_len(info + 16 - l, cryptlen, l);
}

static int format_adata(u8 *adata, unsigned int a)
{
        int len = 0;

        /* add control info for associated data
         * RFC 3610 and NIST Special Publication 800-38C
         */
        if (a < 65280) {
                *(__be16 *)adata = cpu_to_be16(a);
                len = 2;
        } else  {
                *(__be16 *)adata = cpu_to_be16(0xfffe);
                *(__be32 *)&adata[2] = cpu_to_be32(a);
                len = 6;
        }

        return len;
}

static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
                           unsigned int cryptlen)
{
        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
        struct crypto_aead *aead = crypto_aead_reqtfm(req);
        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
        struct ahash_request *ahreq = &pctx->ahreq;
        unsigned int assoclen = req->assoclen;
        struct scatterlist sg[3];
        u8 *odata = pctx->odata;
        u8 *idata = pctx->idata;
        int ilen, err;

        /* format control data for input */
        err = format_input(odata, req, cryptlen);
        if (err)
                goto out;

        sg_init_table(sg, 3);
        sg_set_buf(&sg[0], odata, 16);

        /* format associated data and compute into mac */
        if (assoclen) {
                ilen = format_adata(idata, assoclen);
                sg_set_buf(&sg[1], idata, ilen);
                sg_chain(sg, 3, req->src);
        } else {
                ilen = 0;
                sg_chain(sg, 2, req->src);
        }

        ahash_request_set_tfm(ahreq, ctx->mac);
        ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
        ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
        err = crypto_ahash_init(ahreq);
        if (err)
                goto out;
        err = crypto_ahash_update(ahreq);
        if (err)
                goto out;

        /* we need to pad the MAC input to a round multiple of the block size */
        ilen = 16 - (assoclen + ilen) % 16;
        if (ilen < 16) {
                memset(idata, 0, ilen);
                sg_init_table(sg, 2);
                sg_set_buf(&sg[0], idata, ilen);
                if (plain)
                        sg_chain(sg, 2, plain);
                plain = sg;
                cryptlen += ilen;
        }

        ahash_request_set_crypt(ahreq, plain, odata, cryptlen);
        err = crypto_ahash_finup(ahreq);
out:
        return err;
}

static void crypto_ccm_encrypt_done(void *data, int err)
{
        struct aead_request *req = data;
        struct crypto_aead *aead = crypto_aead_reqtfm(req);
        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
        u8 *odata = pctx->odata;

        if (!err)
                scatterwalk_map_and_copy(odata, req->dst,
                                         req->assoclen + req->cryptlen,
                                         crypto_aead_authsize(aead), 1);
        aead_request_complete(req, err);
}

static inline int crypto_ccm_check_iv(const u8 *iv)
{
        /* 2 <= L <= 8, so 1 <= L' <= 7. */
        if (1 > iv[0] || iv[0] > 7)
                return -EINVAL;

        return 0;
}

static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
{
        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
        struct scatterlist *sg;
        u8 *iv = req->iv;
        int err;

        err = crypto_ccm_check_iv(iv);
        if (err)
                return err;

        pctx->flags = aead_request_flags(req);

         /* Note: rfc 3610 and NIST 800-38C require counter of
         * zero to encrypt auth tag.
         */
        memset(iv + 15 - iv[0], 0, iv[0] + 1);

        sg_init_table(pctx->src, 3);
        sg_set_buf(pctx->src, tag, 16);
        sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
        if (sg != pctx->src + 1)
                sg_chain(pctx->src, 2, sg);

        if (req->src != req->dst) {
                sg_init_table(pctx->dst, 3);
                sg_set_buf(pctx->dst, tag, 16);
                sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
                if (sg != pctx->dst + 1)
                        sg_chain(pctx->dst, 2, sg);
        }

        return 0;
}

static int crypto_ccm_encrypt(struct aead_request *req)
{
        struct crypto_aead *aead = crypto_aead_reqtfm(req);
        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
        struct skcipher_request *skreq = &pctx->skreq;
        struct scatterlist *dst;
        unsigned int cryptlen = req->cryptlen;
        u8 *odata = pctx->odata;
        u8 *iv = req->iv;
        int err;

        err = crypto_ccm_init_crypt(req, odata);
        if (err)
                return err;

        err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
        if (err)
                return err;

        dst = pctx->src;
        if (req->src != req->dst)
                dst = pctx->dst;

        skcipher_request_set_tfm(skreq, ctx->ctr);
        skcipher_request_set_callback(skreq, pctx->flags,
                                      crypto_ccm_encrypt_done, req);
        skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
        err = crypto_skcipher_encrypt(skreq);
        if (err)
                return err;

        /* copy authtag to end of dst */
        scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
                                 crypto_aead_authsize(aead), 1);
        return err;
}

static void crypto_ccm_decrypt_done(void *data, int err)
{
        struct aead_request *req = data;
        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
        struct crypto_aead *aead = crypto_aead_reqtfm(req);
        unsigned int authsize = crypto_aead_authsize(aead);
        unsigned int cryptlen = req->cryptlen - authsize;
        struct scatterlist *dst;

        pctx->flags = 0;

        dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);

        if (!err) {
                err = crypto_ccm_auth(req, dst, cryptlen);
                if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
                        err = -EBADMSG;
        }
        aead_request_complete(req, err);
}

static int crypto_ccm_decrypt(struct aead_request *req)
{
        struct crypto_aead *aead = crypto_aead_reqtfm(req);
        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
        struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
        struct skcipher_request *skreq = &pctx->skreq;
        struct scatterlist *dst;
        unsigned int authsize = crypto_aead_authsize(aead);
        unsigned int cryptlen = req->cryptlen;
        u8 *authtag = pctx->auth_tag;
        u8 *odata = pctx->odata;
        u8 *iv = pctx->idata;
        int err;

        cryptlen -= authsize;

        err = crypto_ccm_init_crypt(req, authtag);
        if (err)
                return err;

        scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
                                 authsize, 0);

        dst = pctx->src;
        if (req->src != req->dst)
                dst = pctx->dst;

        memcpy(iv, req->iv, 16);

        skcipher_request_set_tfm(skreq, ctx->ctr);
        skcipher_request_set_callback(skreq, pctx->flags,
                                      crypto_ccm_decrypt_done, req);
        skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
        err = crypto_skcipher_decrypt(skreq);
        if (err)
                return err;

        err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
        if (err)
                return err;

        /* verify */
        if (crypto_memneq(authtag, odata, authsize))
                return -EBADMSG;

        return err;
}

static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
{
        struct aead_instance *inst = aead_alg_instance(tfm);
        struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
        struct crypto_ahash *mac;
        struct crypto_skcipher *ctr;
        unsigned long align;
        int err;

        mac = crypto_spawn_ahash(&ictx->mac);
        if (IS_ERR(mac))
                return PTR_ERR(mac);

        ctr = crypto_spawn_skcipher(&ictx->ctr);
        err = PTR_ERR(ctr);
        if (IS_ERR(ctr))
                goto err_free_mac;

        ctx->mac = mac;
        ctx->ctr = ctr;

        align = crypto_aead_alignmask(tfm);
        align &= ~(crypto_tfm_ctx_alignment() - 1);
        crypto_aead_set_reqsize(
                tfm,
                align + sizeof(struct crypto_ccm_req_priv_ctx) +
                max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));

        return 0;

err_free_mac:
        crypto_free_ahash(mac);
        return err;
}

static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
{
        struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);

        crypto_free_ahash(ctx->mac);
        crypto_free_skcipher(ctx->ctr);
}

static void crypto_ccm_free(struct aead_instance *inst)
{
        struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);

        crypto_drop_ahash(&ctx->mac);
        crypto_drop_skcipher(&ctx->ctr);
        kfree(inst);
}

static int crypto_ccm_create_common(struct crypto_template *tmpl,
                                    struct rtattr **tb,
                                    const char *ctr_name,
                                    const char *mac_name)
{
        struct skcipher_alg_common *ctr;
        u32 mask;
        struct aead_instance *inst;
        struct ccm_instance_ctx *ictx;
        struct hash_alg_common *mac;
        int err;

        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
        if (err)
                return err;

        inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
        if (!inst)
                return -ENOMEM;
        ictx = aead_instance_ctx(inst);

        err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
                                mac_name, 0, mask | CRYPTO_ALG_ASYNC);
        if (err)
                goto err_free_inst;
        mac = crypto_spawn_ahash_alg(&ictx->mac);

        err = -EINVAL;
        if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
            mac->digestsize != 16)
                goto err_free_inst;

        err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
                                   ctr_name, 0, mask);
        if (err)
                goto err_free_inst;
        ctr = crypto_spawn_skcipher_alg_common(&ictx->ctr);

        /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
        err = -EINVAL;
        if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
            ctr->ivsize != 16 || ctr->base.cra_blocksize != 1)
                goto err_free_inst;

        /* ctr and cbcmac must use the same underlying block cipher. */
        if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
                goto err_free_inst;

        err = -ENAMETOOLONG;
        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
                     "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
                goto err_free_inst;

        if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
                     "ccm_base(%s,%s)", ctr->base.cra_driver_name,
                     mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
                goto err_free_inst;

        inst->alg.base.cra_priority = (mac->base.cra_priority +
                                       ctr->base.cra_priority) / 2;
        inst->alg.base.cra_blocksize = 1;
        inst->alg.base.cra_alignmask = ctr->base.cra_alignmask;
        inst->alg.ivsize = 16;
        inst->alg.chunksize = ctr->chunksize;
        inst->alg.maxauthsize = 16;
        inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
        inst->alg.init = crypto_ccm_init_tfm;
        inst->alg.exit = crypto_ccm_exit_tfm;
        inst->alg.setkey = crypto_ccm_setkey;
        inst->alg.setauthsize = crypto_ccm_setauthsize;
        inst->alg.encrypt = crypto_ccm_encrypt;
        inst->alg.decrypt = crypto_ccm_decrypt;

        inst->free = crypto_ccm_free;

        err = aead_register_instance(tmpl, inst);
        if (err) {
err_free_inst:
                crypto_ccm_free(inst);
        }
        return err;
}

static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
{
        const char *cipher_name;
        char ctr_name[CRYPTO_MAX_ALG_NAME];
        char mac_name[CRYPTO_MAX_ALG_NAME];

        cipher_name = crypto_attr_alg_name(tb[1]);
        if (IS_ERR(cipher_name))
                return PTR_ERR(cipher_name);

        if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
                     cipher_name) >= CRYPTO_MAX_ALG_NAME)
                return -ENAMETOOLONG;

        if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
                     cipher_name) >= CRYPTO_MAX_ALG_NAME)
                return -ENAMETOOLONG;

        return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
}

static int crypto_ccm_base_create(struct crypto_template *tmpl,
                                  struct rtattr **tb)
{
        const char *ctr_name;
        const char *mac_name;

        ctr_name = crypto_attr_alg_name(tb[1]);
        if (IS_ERR(ctr_name))
                return PTR_ERR(ctr_name);

        mac_name = crypto_attr_alg_name(tb[2]);
        if (IS_ERR(mac_name))
                return PTR_ERR(mac_name);

        return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
}

static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
                                 unsigned int keylen)
{
        struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
        struct crypto_aead *child = ctx->child;

        if (keylen < 3)
                return -EINVAL;

        keylen -= 3;
        memcpy(ctx->nonce, key + keylen, 3);

        crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
        crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
                                     CRYPTO_TFM_REQ_MASK);
        return crypto_aead_setkey(child, key, keylen);
}

static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
                                      unsigned int authsize)
{
        struct crypto_rfc4309_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_rfc4309_crypt(struct aead_request *req)
{
        struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
        struct aead_request *subreq = &rctx->subreq;
        struct crypto_aead *aead = crypto_aead_reqtfm(req);
        struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
        struct crypto_aead *child = ctx->child;
        struct scatterlist *sg;
        u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
                           crypto_aead_alignmask(child) + 1);

        /* L' */
        iv[0] = 3;

        memcpy(iv + 1, ctx->nonce, 3);
        memcpy(iv + 4, req->iv, 8);

        scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);

        sg_init_table(rctx->src, 3);
        sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
        sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
        if (sg != rctx->src + 1)
                sg_chain(rctx->src, 2, sg);

        if (req->src != req->dst) {
                sg_init_table(rctx->dst, 3);
                sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
                sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
                if (sg != rctx->dst + 1)
                        sg_chain(rctx->dst, 2, sg);
        }

        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, rctx->src,
                               req->src == req->dst ? rctx->src : rctx->dst,
                               req->cryptlen, iv);
        aead_request_set_ad(subreq, req->assoclen - 8);

        return subreq;
}

static int crypto_rfc4309_encrypt(struct aead_request *req)
{
        if (req->assoclen != 16 && req->assoclen != 20)
                return -EINVAL;

        req = crypto_rfc4309_crypt(req);

        return crypto_aead_encrypt(req);
}

static int crypto_rfc4309_decrypt(struct aead_request *req)
{
        if (req->assoclen != 16 && req->assoclen != 20)
                return -EINVAL;

        req = crypto_rfc4309_crypt(req);

        return crypto_aead_decrypt(req);
}

static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
{
        struct aead_instance *inst = aead_alg_instance(tfm);
        struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
        struct crypto_rfc4309_ctx *ctx = crypto_aead_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);
        crypto_aead_set_reqsize(
                tfm,
                sizeof(struct crypto_rfc4309_req_ctx) +
                ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
                align + 32);

        return 0;
}

static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
{
        struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);

        crypto_free_aead(ctx->child);
}

static void crypto_rfc4309_free(struct aead_instance *inst)
{
        crypto_drop_aead(aead_instance_ctx(inst));
        kfree(inst);
}

static int crypto_rfc4309_create(struct crypto_template *tmpl,
                                 struct rtattr **tb)
{
        u32 mask;
        struct aead_instance *inst;
        struct crypto_aead_spawn *spawn;
        struct aead_alg *alg;
        int err;

        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
        if (err)
                return err;

        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
        if (!inst)
                return -ENOMEM;

        spawn = aead_instance_ctx(inst);
        err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
                               crypto_attr_alg_name(tb[1]), 0, mask);
        if (err)
                goto err_free_inst;

        alg = crypto_spawn_aead_alg(spawn);

        err = -EINVAL;

        /* We only support 16-byte blocks. */
        if (crypto_aead_alg_ivsize(alg) != 16)
                goto err_free_inst;

        /* Not a stream cipher? */
        if (alg->base.cra_blocksize != 1)
                goto err_free_inst;

        err = -ENAMETOOLONG;
        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
                     "rfc4309(%s)", alg->base.cra_name) >=
            CRYPTO_MAX_ALG_NAME ||
            snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
                     "rfc4309(%s)", alg->base.cra_driver_name) >=
            CRYPTO_MAX_ALG_NAME)
                goto err_free_inst;

        inst->alg.base.cra_priority = alg->base.cra_priority;
        inst->alg.base.cra_blocksize = 1;
        inst->alg.base.cra_alignmask = alg->base.cra_alignmask;

        inst->alg.ivsize = 8;
        inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
        inst->alg.maxauthsize = 16;

        inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);

        inst->alg.init = crypto_rfc4309_init_tfm;
        inst->alg.exit = crypto_rfc4309_exit_tfm;

        inst->alg.setkey = crypto_rfc4309_setkey;
        inst->alg.setauthsize = crypto_rfc4309_setauthsize;
        inst->alg.encrypt = crypto_rfc4309_encrypt;
        inst->alg.decrypt = crypto_rfc4309_decrypt;

        inst->free = crypto_rfc4309_free;

        err = aead_register_instance(tmpl, inst);
        if (err) {
err_free_inst:
                crypto_rfc4309_free(inst);
        }
        return err;
}

static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
                                     const u8 *inkey, unsigned int keylen)
{
        struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);

        return crypto_cipher_setkey(ctx->child, inkey, keylen);
}

static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
{
        int bs = crypto_shash_digestsize(pdesc->tfm);
        u8 *dg = shash_desc_ctx(pdesc);

        memset(dg, 0, bs);
        return 0;
}

static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
                                       unsigned int len)
{
        struct crypto_shash *parent = pdesc->tfm;
        struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
        struct crypto_cipher *tfm = tctx->child;
        int bs = crypto_shash_digestsize(parent);
        u8 *dg = shash_desc_ctx(pdesc);

        do {
                crypto_xor(dg, p, bs);
                crypto_cipher_encrypt_one(tfm, dg, dg);
                p += bs;
                len -= bs;
        } while (len >= bs);
        return len;
}

static int crypto_cbcmac_digest_finup(struct shash_desc *pdesc, const u8 *src,
                                      unsigned int len, u8 *out)
{
        struct crypto_shash *parent = pdesc->tfm;
        struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
        struct crypto_cipher *tfm = tctx->child;
        int bs = crypto_shash_digestsize(parent);
        u8 *dg = shash_desc_ctx(pdesc);

        if (len) {
                crypto_xor(dg, src, len);
                crypto_cipher_encrypt_one(tfm, out, dg);
                return 0;
        }
        memcpy(out, dg, bs);
        return 0;
}

static int cbcmac_init_tfm(struct crypto_tfm *tfm)
{
        struct crypto_cipher *cipher;
        struct crypto_instance *inst = (void *)tfm->__crt_alg;
        struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
        struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);

        cipher = crypto_spawn_cipher(spawn);
        if (IS_ERR(cipher))
                return PTR_ERR(cipher);

        ctx->child = cipher;

        return 0;
};

static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
{
        struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
        crypto_free_cipher(ctx->child);
}

static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
{
        struct shash_instance *inst;
        struct crypto_cipher_spawn *spawn;
        struct crypto_alg *alg;
        u32 mask;
        int err;

        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
        if (err)
                return err;

        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
        if (!inst)
                return -ENOMEM;
        spawn = shash_instance_ctx(inst);

        err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
                                 crypto_attr_alg_name(tb[1]), 0, mask);
        if (err)
                goto err_free_inst;
        alg = crypto_spawn_cipher_alg(spawn);

        err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
        if (err)
                goto err_free_inst;

        inst->alg.base.cra_priority = alg->cra_priority;
        inst->alg.base.cra_blocksize = alg->cra_blocksize;

        inst->alg.digestsize = alg->cra_blocksize;
        inst->alg.descsize = alg->cra_blocksize;

        inst->alg.base.cra_flags = CRYPTO_AHASH_ALG_BLOCK_ONLY;
        inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
        inst->alg.base.cra_init = cbcmac_init_tfm;
        inst->alg.base.cra_exit = cbcmac_exit_tfm;

        inst->alg.init = crypto_cbcmac_digest_init;
        inst->alg.update = crypto_cbcmac_digest_update;
        inst->alg.finup = crypto_cbcmac_digest_finup;
        inst->alg.setkey = crypto_cbcmac_digest_setkey;

        inst->free = shash_free_singlespawn_instance;

        err = shash_register_instance(tmpl, inst);
        if (err) {
err_free_inst:
                shash_free_singlespawn_instance(inst);
        }
        return err;
}

static struct crypto_template crypto_ccm_tmpls[] = {
        {
                .name = "cbcmac",
                .create = cbcmac_create,
                .module = THIS_MODULE,
        }, {
                .name = "ccm_base",
                .create = crypto_ccm_base_create,
                .module = THIS_MODULE,
        }, {
                .name = "ccm",
                .create = crypto_ccm_create,
                .module = THIS_MODULE,
        }, {
                .name = "rfc4309",
                .create = crypto_rfc4309_create,
                .module = THIS_MODULE,
        },
};

static int __init crypto_ccm_module_init(void)
{
        return crypto_register_templates(crypto_ccm_tmpls,
                                         ARRAY_SIZE(crypto_ccm_tmpls));
}

static void __exit crypto_ccm_module_exit(void)
{
        crypto_unregister_templates(crypto_ccm_tmpls,
                                    ARRAY_SIZE(crypto_ccm_tmpls));
}

module_init(crypto_ccm_module_init);
module_exit(crypto_ccm_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Counter with CBC MAC");
MODULE_ALIAS_CRYPTO("ccm_base");
MODULE_ALIAS_CRYPTO("rfc4309");
MODULE_ALIAS_CRYPTO("ccm");
MODULE_ALIAS_CRYPTO("cbcmac");
MODULE_IMPORT_NS("CRYPTO_INTERNAL");