crypto/seqiv.c - linux/kernel/git/klassert/ipsec - Git at Google

 /*
  * 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);
 	err = PTR_ERR(algt);
 	if (IS_ERR(algt))
 		return ERR_PTR(err);

 	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");
	/*
	* 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);
	err = PTR_ERR(algt);
	if (IS_ERR(algt))
	return ERR_PTR(err);

	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");