/* * seqiv: Sequence Number IV Generator * * This generator generates an IV based on a sequence number by xoring it * with a salt.  This algorithm is mainly useful for CTR and similar modes. * * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * */ #include <crypto/internal/aead.h>#include <crypto/internal/skcipher.h>#include <crypto/rng.h>#include <linux/err.h>#include <linux/init.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/spinlock.h>#include <linux/string.h> struct seqiv_ctx {	spinlock_t lock;	u8 salt[] __attribute__ ((aligned(__alignof__(u32))));}; static void seqiv_complete2(struct skcipher_givcrypt_request *req, int err){	struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req);	struct crypto_ablkcipher *geniv; 	if (err == -EINPROGRESS)		return; 	if (err)		goto out; 	geniv = skcipher_givcrypt_reqtfm(req);	memcpy(req->creq.info, subreq->info, crypto_ablkcipher_ivsize(geniv)); out:	kfree(subreq->info);} static void seqiv_complete(struct crypto_async_request *base, int err){	struct skcipher_givcrypt_request *req = base->data; 	seqiv_complete2(req, err);	skcipher_givcrypt_complete(req, err);} static void seqiv_aead_complete2(struct aead_givcrypt_request *req, int err){	struct aead_request *subreq = aead_givcrypt_reqctx(req);	struct crypto_aead *geniv; 	if (err == -EINPROGRESS)		return; 	if (err)		goto out; 	geniv = aead_givcrypt_reqtfm(req);	memcpy(req->areq.iv, subreq->iv, crypto_aead_ivsize(geniv)); out:	kfree(subreq->iv);} static void seqiv_aead_complete(struct crypto_async_request *base, int err){	struct aead_givcrypt_request *req = base->data; 	seqiv_aead_complete2(req, err);	aead_givcrypt_complete(req, err);} static void seqiv_geniv(struct seqiv_ctx *ctx, u8 *info, u64 seq,			unsigned int ivsize){	unsigned int len = ivsize; 	if (ivsize > sizeof(u64)) {		memset(info, 0, ivsize - sizeof(u64));		len = sizeof(u64);	}	seq = cpu_to_be64(seq);	memcpy(info + ivsize - len, &seq, len);	crypto_xor(info, ctx->salt, ivsize);} static int seqiv_givencrypt(struct skcipher_givcrypt_request *req){	struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);	struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);	struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req);	crypto_completion_t complete;	void *data;	u8 *info;	unsigned int ivsize;	int err; 	ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv)); 	complete = req->creq.base.complete;	data = req->creq.base.data;	info = req->creq.info; 	ivsize = crypto_ablkcipher_ivsize(geniv); 	if (unlikely(!IS_ALIGNED((unsigned long)info,				 crypto_ablkcipher_alignmask(geniv) + 1))) {		info = kmalloc(ivsize, req->creq.base.flags &				       CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:								  GFP_ATOMIC);		if (!info)			return -ENOMEM; 		complete = seqiv_complete;		data = req;	} 	ablkcipher_request_set_callback(subreq, req->creq.base.flags, complete,					data);	ablkcipher_request_set_crypt(subreq, req->creq.src, req->creq.dst,				     req->creq.nbytes, info); 	seqiv_geniv(ctx, info, req->seq, ivsize);	memcpy(req->giv, info, ivsize); 	err = crypto_ablkcipher_encrypt(subreq);	if (unlikely(info != req->creq.info))		seqiv_complete2(req, err);	return err;} static int seqiv_aead_givencrypt(struct aead_givcrypt_request *req){	struct crypto_aead *geniv = aead_givcrypt_reqtfm(req);	struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);	struct aead_request *areq = &req->areq;	struct aead_request *subreq = aead_givcrypt_reqctx(req);	crypto_completion_t complete;	void *data;	u8 *info;	unsigned int ivsize;	int err; 	aead_request_set_tfm(subreq, aead_geniv_base(geniv)); 	complete = areq->base.complete;	data = areq->base.data;	info = areq->iv; 	ivsize = crypto_aead_ivsize(geniv); 	if (unlikely(!IS_ALIGNED((unsigned long)info,				 crypto_aead_alignmask(geniv) + 1))) {		info = kmalloc(ivsize, areq->base.flags &				       CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:								  GFP_ATOMIC);		if (!info)			return -ENOMEM; 		complete = seqiv_aead_complete;		data = req;	} 	aead_request_set_callback(subreq, areq->base.flags, complete, data);	aead_request_set_crypt(subreq, areq->src, areq->dst, areq->cryptlen,			       info);	aead_request_set_assoc(subreq, areq->assoc, areq->assoclen); 	seqiv_geniv(ctx, info, req->seq, ivsize);	memcpy(req->giv, info, ivsize); 	err = crypto_aead_encrypt(subreq);	if (unlikely(info != areq->iv))		seqiv_aead_complete2(req, err);	return err;} static int seqiv_givencrypt_first(struct skcipher_givcrypt_request *req){	struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);	struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);	int err = 0; 	spin_lock_bh(&ctx->lock);	if (crypto_ablkcipher_crt(geniv)->givencrypt != seqiv_givencrypt_first)		goto unlock; 	crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt;	err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,				   crypto_ablkcipher_ivsize(geniv)); unlock:	spin_unlock_bh(&ctx->lock); 	if (err)		return err; 	return seqiv_givencrypt(req);} static int seqiv_aead_givencrypt_first(struct aead_givcrypt_request *req){	struct crypto_aead *geniv = aead_givcrypt_reqtfm(req);	struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);	int err = 0; 	spin_lock_bh(&ctx->lock);	if (crypto_aead_crt(geniv)->givencrypt != seqiv_aead_givencrypt_first)		goto unlock; 	crypto_aead_crt(geniv)->givencrypt = seqiv_aead_givencrypt;	err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,				   crypto_aead_ivsize(geniv)); unlock:	spin_unlock_bh(&ctx->lock); 	if (err)		return err; 	return seqiv_aead_givencrypt(req);} static int seqiv_init(struct crypto_tfm *tfm){	struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);	struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv); 	spin_lock_init(&ctx->lock); 	tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request); 	return skcipher_geniv_init(tfm);} static int seqiv_aead_init(struct crypto_tfm *tfm){	struct crypto_aead *geniv = __crypto_aead_cast(tfm);	struct seqiv_ctx *ctx = crypto_aead_ctx(geniv); 	spin_lock_init(&ctx->lock); 	tfm->crt_aead.reqsize = sizeof(struct aead_request); 	return aead_geniv_init(tfm);} static struct crypto_template seqiv_tmpl; static struct crypto_instance *seqiv_ablkcipher_alloc(struct rtattr **tb){	struct crypto_instance *inst; 	inst = skcipher_geniv_alloc(&seqiv_tmpl, tb, 0, 0); 	if (IS_ERR(inst))		goto out; 	inst->alg.cra_ablkcipher.givencrypt = seqiv_givencrypt_first; 	inst->alg.cra_init = seqiv_init;	inst->alg.cra_exit = skcipher_geniv_exit; 	inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize; out:	return inst;} static struct crypto_instance *seqiv_aead_alloc(struct rtattr **tb){	struct crypto_instance *inst; 	inst = aead_geniv_alloc(&seqiv_tmpl, tb, 0, 0); 	if (IS_ERR(inst))		goto out; 	inst->alg.cra_aead.givencrypt = seqiv_aead_givencrypt_first; 	inst->alg.cra_init = seqiv_aead_init;	inst->alg.cra_exit = aead_geniv_exit; 	inst->alg.cra_ctxsize = inst->alg.cra_aead.ivsize; out:	return inst;} static struct crypto_instance *seqiv_alloc(struct rtattr **tb){	struct crypto_attr_type *algt;	struct crypto_instance *inst;	int err; 	algt = crypto_get_attr_type(tb);	if (IS_ERR(algt))		return ERR_CAST(algt); 	err = crypto_get_default_rng();	if (err)		return ERR_PTR(err); 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)		inst = seqiv_ablkcipher_alloc(tb);	else		inst = seqiv_aead_alloc(tb); 	if (IS_ERR(inst))		goto put_rng; 	inst->alg.cra_alignmask |= __alignof__(u32) - 1;	inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx); out:	return inst; put_rng:	crypto_put_default_rng();	goto out;} static void seqiv_free(struct crypto_instance *inst){	if ((inst->alg.cra_flags ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)		skcipher_geniv_free(inst);	else		aead_geniv_free(inst);	crypto_put_default_rng();} static struct crypto_template seqiv_tmpl = {	.name = "seqiv",	.alloc = seqiv_alloc,	.free = seqiv_free,	.module = THIS_MODULE,}; static int __init seqiv_module_init(void){	return crypto_register_template(&seqiv_tmpl);} static void __exit seqiv_module_exit(void){	crypto_unregister_template(&seqiv_tmpl);} module_init(seqiv_module_init);module_exit(seqiv_module_exit); MODULE_LICENSE("GPL");MODULE_DESCRIPTION("Sequence Number IV Generator");