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41 results

neverallow_macros

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    • Nick Kralevich's avatar
      acc0842c
      system_server: neverallow blk_file read/write · acc0842c
      Nick Kralevich authored
      With the exception of the factory reset protection block device,
      don't allow system_server to read or write to any other block
      devices. This helps protect against a system->root escalation
      when system_server has the ability to directly minipulate raw
      block devices / partitions / partition tables.
      
      This change adds a neverallow rule, which is a compile time
      assertion that no SELinux policy is written which allows this
      access. No new rules are added or removed.
      
      Change-Id: I388408423097ef7cf4950197b79d4be9d666362c
      acc0842c
      History
      system_server: neverallow blk_file read/write
      Nick Kralevich authored
      With the exception of the factory reset protection block device,
      don't allow system_server to read or write to any other block
      devices. This helps protect against a system->root escalation
      when system_server has the ability to directly minipulate raw
      block devices / partitions / partition tables.
      
      This change adds a neverallow rule, which is a compile time
      assertion that no SELinux policy is written which allows this
      access. No new rules are added or removed.
      
      Change-Id: I388408423097ef7cf4950197b79d4be9d666362c
    gcm.c 36.54 KiB
    /*
     * 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/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>
    #include <linux/kernel.h>
    #include <linux/module.h>
    #include <linux/slab.h>
    
    struct gcm_instance_ctx {
    	struct crypto_skcipher_spawn ctr;
    	struct crypto_ahash_spawn ghash;
    };
    
    struct crypto_gcm_ctx {
    	struct crypto_ablkcipher *ctr;
    	struct crypto_ahash *ghash;
    };
    
    struct crypto_rfc4106_ctx {
    	struct crypto_aead *child;
    	u8 nonce[4];
    };
    
    struct crypto_rfc4543_instance_ctx {
    	struct crypto_aead_spawn aead;
    	struct crypto_skcipher_spawn null;
    };
    
    struct crypto_rfc4543_ctx {
    	struct crypto_aead *child;
    	struct crypto_blkcipher *null;
    	u8 nonce[4];
    };
    
    struct crypto_rfc4543_req_ctx {
    	u8 auth_tag[16];
    	u8 assocbuf[32];
    	struct scatterlist cipher[1];
    	struct scatterlist payload[2];
    	struct scatterlist assoc[2];
    	struct aead_request subreq;
    };
    
    struct crypto_gcm_ghash_ctx {
    	unsigned int cryptlen;
    	struct scatterlist *src;
    	void (*complete)(struct aead_request *req, int err);
    };
    
    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_ctx;
    	union {
    		struct ahash_request ahreq;
    		struct ablkcipher_request abreq;
    	} u;
    };
    
    struct crypto_gcm_setkey_result {
    	int err;
    	struct completion completion;
    };
    
    static void *gcm_zeroes;
    
    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_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_ahash *ghash = ctx->ghash;
    	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;
    
    	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);
    	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);
    	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);
    }
    
    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);
    
    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;
    
    	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 gcm_hash_remain(struct aead_request *req,
    			   struct crypto_gcm_req_priv_ctx *pctx,
    			   unsigned int remain,
    			   crypto_completion_t complete)
    {
    	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 aead_request *req, int err)
    {
    	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
    	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
    
    	if (!err)
    		crypto_xor(pctx->auth_tag, pctx->iauth_tag, 16);
    
    	gctx->complete(req, err);
    }
    
    static void gcm_hash_final_done(struct crypto_async_request *areq, int err)
    {
    	struct aead_request *req = areq->data;
    
    	__gcm_hash_final_done(req, err);
    }
    
    static void __gcm_hash_len_done(struct aead_request *req, int err)
    {
    	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(req, err);
    }
    
    static void gcm_hash_len_done(struct crypto_async_request *areq, int err)
    {
    	struct aead_request *req = areq->data;
    
    	__gcm_hash_len_done(req, err);
    }
    
    static void __gcm_hash_crypt_remain_done(struct aead_request *req, int err)
    {
    	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(req, err);
    }
    
    static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq,
    				       int err)
    {
    	struct aead_request *req = areq->data;
    
    	__gcm_hash_crypt_remain_done(req, err);
    }
    
    static void __gcm_hash_crypt_done(struct aead_request *req, int err)
    {
    	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(req, err);
    }
    
    static void gcm_hash_crypt_done(struct crypto_async_request *areq, int err)
    {
    	struct aead_request *req = areq->data;
    
    	__gcm_hash_crypt_done(req, err);
    }
    
    static void __gcm_hash_assoc_remain_done(struct aead_request *req, int err)
    {
    	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(req, err);
    	else
    		__gcm_hash_crypt_remain_done(req, err);
    }
    
    static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq,
    				       int err)
    {
    	struct aead_request *req = areq->data;
    
    	__gcm_hash_assoc_remain_done(req, err);
    }
    
    static void __gcm_hash_assoc_done(struct aead_request *req, int err)
    {
    	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(req, err);
    }
    
    static void gcm_hash_assoc_done(struct crypto_async_request *areq, int err)
    {
    	struct aead_request *req = areq->data;
    
    	__gcm_hash_assoc_done(req, err);
    }
    
    static void __gcm_hash_init_done(struct aead_request *req, int err)
    {
    	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(req, err);
    	else
    		__gcm_hash_assoc_remain_done(req, err);
    }
    
    static void gcm_hash_init_done(struct crypto_async_request *areq, int err)
    {
    	struct aead_request *req = areq->data;
    
    	__gcm_hash_init_done(req, 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);
    }
    
    static void gcm_enc_hash_done(struct aead_request *req, int err)
    {
    	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
    
    	if (!err)
    		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;
    		else if (!err) {
    			crypto_xor(pctx->auth_tag, pctx->iauth_tag, 16);
    			gcm_enc_copy_hash(req, pctx);
    		}
    	}
    
    	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->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),
    					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;
    
    	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,
    			     struct crypto_gcm_req_priv_ctx *pctx)
    {
    	struct crypto_aead *aead = crypto_aead_reqtfm(req);
    	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_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 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, pctx);
    
    	aead_request_complete(req, err);
    }
    
    static void gcm_dec_hash_done(struct aead_request *req, int err)
    {
    	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;
    		else if (!err)
    			err = crypto_gcm_verify(req, pctx);
    	}
    
    	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->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;
    
    	gctx->src = req->src;
    	gctx->cryptlen = cryptlen;
    	gctx->complete = gcm_dec_hash_done;
    
    	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, pctx);
    }
    
    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;
    	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))
    		goto err_free_hash;
    
    	ctx->ctr = ctr;
    	ctx->ghash = ghash;
    
    	align = crypto_tfm_alg_alignmask(tfm);
    	align &= ~(crypto_tfm_ctx_alignment() - 1);
    	tfm->crt_aead.reqsize = align +
    		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);
    
    	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 *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;
    
    	algt = crypto_get_attr_type(tb);
    	if (IS_ERR(algt))
    		return ERR_CAST(algt);
    
    	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);
    	if (IS_ERR(ghash_alg))
    		return ERR_CAST(ghash_alg);
    
    	err = -ENOMEM;
    	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
    	if (!inst)
    		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_drop_ghash;
    
    	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,%s)", ctr->cra_driver_name,
    		     ghash_alg->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:
    	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;
    }
    
    static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
    {
    	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]);
    	if (IS_ERR(cipher_name))
    		return ERR_CAST(cipher_name);
    
    	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, "ghash");
    }
    
    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);
    }
    
    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)
    {
    	const char *ctr_name;
    	const char *ghash_name;
    	char full_name[CRYPTO_MAX_ALG_NAME];
    
    	ctr_name = crypto_attr_alg_name(tb[1]);
    	if (IS_ERR(ctr_name))
    		return ERR_CAST(ctr_name);
    
    	ghash_name = crypto_attr_alg_name(tb[2]);
    	if (IS_ERR(ghash_name))
    		return ERR_CAST(ghash_name);
    
    	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, ghash_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);
    	if (IS_ERR(algt))
    		return ERR_CAST(algt);
    
    	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
    		return ERR_PTR(-EINVAL);
    
    	ccm_name = crypto_attr_alg_name(tb[1]);
    	if (IS_ERR(ccm_name))
    		return ERR_CAST(ccm_name);
    
    	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 inline struct crypto_rfc4543_req_ctx *crypto_rfc4543_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 crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
    				 unsigned int keylen)
    {
    	struct crypto_rfc4543_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_rfc4543_setauthsize(struct crypto_aead *parent,
    				      unsigned int authsize)
    {
    	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
    
    	if (authsize != 16)
    		return -EINVAL;
    
    	return crypto_aead_setauthsize(ctx->child, authsize);
    }
    
    static void crypto_rfc4543_done(struct crypto_async_request *areq, int err)
    {
    	struct aead_request *req = areq->data;
    	struct crypto_aead *aead = crypto_aead_reqtfm(req);
    	struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req);
    
    	if (!err) {
    		scatterwalk_map_and_copy(rctx->auth_tag, req->dst,
    					 req->cryptlen,
    					 crypto_aead_authsize(aead), 1);
    	}
    
    	aead_request_complete(req, err);
    }
    
    static struct aead_request *crypto_rfc4543_crypt(struct aead_request *req,
    						 bool enc)
    {
    	struct crypto_aead *aead = crypto_aead_reqtfm(req);
    	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
    	struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req);
    	struct aead_request *subreq = &rctx->subreq;
    	struct scatterlist *src = req->src;
    	struct scatterlist *cipher = rctx->cipher;
    	struct scatterlist *payload = rctx->payload;
    	struct scatterlist *assoc = rctx->assoc;
    	unsigned int authsize = crypto_aead_authsize(aead);
    	unsigned int assoclen = req->assoclen;
    	struct page *srcp;
    	u8 *vsrc;
    	u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
    			   crypto_aead_alignmask(ctx->child) + 1);
    
    	memcpy(iv, ctx->nonce, 4);
    	memcpy(iv + 4, req->iv, 8);
    
    	/* construct cipher/plaintext */
    	if (enc)
    		memset(rctx->auth_tag, 0, authsize);
    	else
    		scatterwalk_map_and_copy(rctx->auth_tag, src,
    					 req->cryptlen - authsize,
    					 authsize, 0);
    
    	sg_init_one(cipher, rctx->auth_tag, authsize);
    
    	/* construct the aad */
    	srcp = sg_page(src);
    	vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
    
    	sg_init_table(payload, 2);
    	sg_set_buf(payload, req->iv, 8);
    	scatterwalk_crypto_chain(payload, src, vsrc == req->iv + 8, 2);
    	assoclen += 8 + req->cryptlen - (enc ? 0 : authsize);
    
    	if (req->assoc->length == req->assoclen) {
    		sg_init_table(assoc, 2);
    		sg_set_page(assoc, sg_page(req->assoc), req->assoc->length,
    			    req->assoc->offset);
    	} else {
    		BUG_ON(req->assoclen > sizeof(rctx->assocbuf));
    
    		scatterwalk_map_and_copy(rctx->assocbuf, req->assoc, 0,
    					 req->assoclen, 0);
    
    		sg_init_table(assoc, 2);
    		sg_set_buf(assoc, rctx->assocbuf, req->assoclen);
    	}
    	scatterwalk_crypto_chain(assoc, payload, 0, 2);
    
    	aead_request_set_tfm(subreq, ctx->child);
    	aead_request_set_callback(subreq, req->base.flags, crypto_rfc4543_done,
    				  req);
    	aead_request_set_crypt(subreq, cipher, cipher, enc ? 0 : authsize, iv);
    	aead_request_set_assoc(subreq, assoc, assoclen);
    
    	return subreq;
    }
    
    static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
    {
    	struct crypto_aead *aead = crypto_aead_reqtfm(req);
    	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
    	unsigned int authsize = crypto_aead_authsize(aead);
    	unsigned int nbytes = req->cryptlen - (enc ? 0 : authsize);
    	struct blkcipher_desc desc = {
    		.tfm = ctx->null,
    	};
    
    	return crypto_blkcipher_encrypt(&desc, req->dst, req->src, nbytes);
    }
    
    static int crypto_rfc4543_encrypt(struct aead_request *req)
    {
    	struct crypto_aead *aead = crypto_aead_reqtfm(req);
    	struct crypto_rfc4543_req_ctx *rctx = crypto_rfc4543_reqctx(req);
    	struct aead_request *subreq;
    	int err;
    
    	if (req->src != req->dst) {
    		err = crypto_rfc4543_copy_src_to_dst(req, true);
    		if (err)
    			return err;
    	}
    
    	subreq = crypto_rfc4543_crypt(req, true);
    	err = crypto_aead_encrypt(subreq);
    	if (err)
    		return err;
    
    	scatterwalk_map_and_copy(rctx->auth_tag, req->dst, req->cryptlen,
    				 crypto_aead_authsize(aead), 1);
    
    	return 0;
    }
    
    static int crypto_rfc4543_decrypt(struct aead_request *req)
    {
    	int err;
    
    	if (req->src != req->dst) {
    		err = crypto_rfc4543_copy_src_to_dst(req, false);
    		if (err)
    			return err;
    	}
    
    	req = crypto_rfc4543_crypt(req, false);
    
    	return crypto_aead_decrypt(req);
    }
    
    static int crypto_rfc4543_init_tfm(struct crypto_tfm *tfm)
    {
    	struct crypto_instance *inst = (void *)tfm->__crt_alg;
    	struct crypto_rfc4543_instance_ctx *ictx = crypto_instance_ctx(inst);
    	struct crypto_aead_spawn *spawn = &ictx->aead;
    	struct crypto_rfc4543_ctx *ctx = crypto_tfm_ctx(tfm);
    	struct crypto_aead *aead;
    	struct crypto_blkcipher *null;
    	unsigned long align;
    	int err = 0;
    
    	aead = crypto_spawn_aead(spawn);
    	if (IS_ERR(aead))
    		return PTR_ERR(aead);
    
    	null = crypto_spawn_blkcipher(&ictx->null.base);
    	err = PTR_ERR(null);
    	if (IS_ERR(null))
    		goto err_free_aead;
    
    	ctx->child = aead;
    	ctx->null = null;
    
    	align = crypto_aead_alignmask(aead);
    	align &= ~(crypto_tfm_ctx_alignment() - 1);
    	tfm->crt_aead.reqsize = sizeof(struct crypto_rfc4543_req_ctx) +
    				ALIGN(crypto_aead_reqsize(aead),
    				      crypto_tfm_ctx_alignment()) +
    				align + 16;
    
    	return 0;
    
    err_free_aead:
    	crypto_free_aead(aead);
    	return err;
    }
    
    static void crypto_rfc4543_exit_tfm(struct crypto_tfm *tfm)
    {
    	struct crypto_rfc4543_ctx *ctx = crypto_tfm_ctx(tfm);
    
    	crypto_free_aead(ctx->child);
    	crypto_free_blkcipher(ctx->null);
    }
    
    static struct crypto_instance *crypto_rfc4543_alloc(struct rtattr **tb)
    {
    	struct crypto_attr_type *algt;
    	struct crypto_instance *inst;
    	struct crypto_aead_spawn *spawn;
    	struct crypto_alg *alg;
    	struct crypto_rfc4543_instance_ctx *ctx;
    	const char *ccm_name;
    	int err;
    
    	algt = crypto_get_attr_type(tb);
    	if (IS_ERR(algt))
    		return ERR_CAST(algt);
    
    	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
    		return ERR_PTR(-EINVAL);
    
    	ccm_name = crypto_attr_alg_name(tb[1]);
    	if (IS_ERR(ccm_name))
    		return ERR_CAST(ccm_name);
    
    	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
    	if (!inst)
    		return ERR_PTR(-ENOMEM);
    
    	ctx = crypto_instance_ctx(inst);
    	spawn = &ctx->aead;
    	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);
    
    	crypto_set_skcipher_spawn(&ctx->null, inst);
    	err = crypto_grab_skcipher(&ctx->null, "ecb(cipher_null)", 0,
    				   CRYPTO_ALG_ASYNC);
    	if (err)
    		goto out_drop_alg;
    
    	crypto_skcipher_spawn_alg(&ctx->null);
    
    	err = -EINVAL;
    
    	/* We only support 16-byte blocks. */
    	if (alg->cra_aead.ivsize != 16)
    		goto out_drop_ecbnull;
    
    	/* Not a stream cipher? */
    	if (alg->cra_blocksize != 1)
    		goto out_drop_ecbnull;
    
    	err = -ENAMETOOLONG;
    	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
    		     "rfc4543(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
    	    snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
    		     "rfc4543(%s)", alg->cra_driver_name) >=
    	    CRYPTO_MAX_ALG_NAME)
    		goto out_drop_ecbnull;
    
    	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_rfc4543_ctx);
    
    	inst->alg.cra_init = crypto_rfc4543_init_tfm;
    	inst->alg.cra_exit = crypto_rfc4543_exit_tfm;
    
    	inst->alg.cra_aead.setkey = crypto_rfc4543_setkey;
    	inst->alg.cra_aead.setauthsize = crypto_rfc4543_setauthsize;
    	inst->alg.cra_aead.encrypt = crypto_rfc4543_encrypt;
    	inst->alg.cra_aead.decrypt = crypto_rfc4543_decrypt;
    
    	inst->alg.cra_aead.geniv = "seqiv";
    
    out:
    	return inst;
    
    out_drop_ecbnull:
    	crypto_drop_skcipher(&ctx->null);
    out_drop_alg:
    	crypto_drop_aead(spawn);
    out_free_inst:
    	kfree(inst);
    	inst = ERR_PTR(err);
    	goto out;
    }
    
    static void crypto_rfc4543_free(struct crypto_instance *inst)
    {
    	struct crypto_rfc4543_instance_ctx *ctx = crypto_instance_ctx(inst);
    
    	crypto_drop_aead(&ctx->aead);
    	crypto_drop_skcipher(&ctx->null);
    
    	kfree(inst);
    }
    
    static struct crypto_template crypto_rfc4543_tmpl = {
    	.name = "rfc4543",
    	.alloc = crypto_rfc4543_alloc,
    	.free = crypto_rfc4543_free,
    	.module = THIS_MODULE,
    };
    
    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;
    
    	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;
    
    	err = crypto_register_template(&crypto_rfc4543_tmpl);
    	if (err)
    		goto out_undo_rfc4106;
    
    	return 0;
    
    out_undo_rfc4106:
    	crypto_unregister_template(&crypto_rfc4106_tmpl);
    out_undo_gcm:
    	crypto_unregister_template(&crypto_gcm_tmpl);
    out_undo_base:
    	crypto_unregister_template(&crypto_gcm_base_tmpl);
    out:
    	kfree(gcm_zeroes);
    	return err;
    }
    
    static void __exit crypto_gcm_module_exit(void)
    {
    	kfree(gcm_zeroes);
    	crypto_unregister_template(&crypto_rfc4543_tmpl);
    	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");
    MODULE_ALIAS("rfc4543");