crypto/seqiv.c - linux-imx - 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/geniv.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/rng.h>
 #include <crypto/scatterwalk.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_free(struct crypto_instance *inst);

 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_encrypt_complete2(struct aead_request *req, int err)
 {
 	struct aead_request *subreq = aead_request_ctx(req);
 	struct crypto_aead *geniv;

 	if (err == -EINPROGRESS)
 		return;

 	if (err)
 		goto out;

 	geniv = crypto_aead_reqtfm(req);
 	memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv));

 out:
 	kzfree(subreq->iv);
 }

 static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
 					int err)
 {
 	struct aead_request *req = base->data;

 	seqiv_aead_encrypt_complete2(req, err);
 	aead_request_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 compl;
 	void *data;
 	u8 *info;
 	unsigned int ivsize;
 	int err;

 	ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv));

 	compl = 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;

 		compl = seqiv_complete;
 		data = req;
 	}

 	ablkcipher_request_set_callback(subreq, req->creq.base.flags, compl,
 					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_encrypt(struct aead_request *req)
 {
 	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
 	struct aead_request *subreq = aead_request_ctx(req);
 	crypto_completion_t compl;
 	void *data;
 	u8 *info;
 	unsigned int ivsize = 8;
 	int err;

 	if (req->cryptlen < ivsize)
 		return -EINVAL;

 	aead_request_set_tfm(subreq, ctx->child);

 	compl = req->base.complete;
 	data = req->base.data;
 	info = req->iv;

 	if (req->src != req->dst) {
 		struct blkcipher_desc desc = {
 			.tfm = ctx->null,
 		};

 		err = crypto_blkcipher_encrypt(&desc, req->dst, req->src,
 					       req->assoclen + req->cryptlen);
 		if (err)
 			return err;
 	}

 	if (unlikely(!IS_ALIGNED((unsigned long)info,
 				 crypto_aead_alignmask(geniv) + 1))) {
 		info = kmalloc(ivsize, req->base.flags &
 				       CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
 								  GFP_ATOMIC);
 		if (!info)
 			return -ENOMEM;

 		memcpy(info, req->iv, ivsize);
 		compl = seqiv_aead_encrypt_complete;
 		data = req;
 	}

 	aead_request_set_callback(subreq, req->base.flags, compl, data);
 	aead_request_set_crypt(subreq, req->dst, req->dst,
 			       req->cryptlen - ivsize, info);
 	aead_request_set_ad(subreq, req->assoclen + ivsize);

 	crypto_xor(info, ctx->salt, ivsize);
 	scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);

 	err = crypto_aead_encrypt(subreq);
 	if (unlikely(info != req->iv))
 		seqiv_aead_encrypt_complete2(req, err);
 	return err;
 }

 static int seqiv_aead_decrypt(struct aead_request *req)
 {
 	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
 	struct aead_request *subreq = aead_request_ctx(req);
 	crypto_completion_t compl;
 	void *data;
 	unsigned int ivsize = 8;

 	if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
 		return -EINVAL;

 	aead_request_set_tfm(subreq, ctx->child);

 	compl = req->base.complete;
 	data = req->base.data;

 	aead_request_set_callback(subreq, req->base.flags, compl, data);
 	aead_request_set_crypt(subreq, req->src, req->dst,
 			       req->cryptlen - ivsize, req->iv);
 	aead_request_set_ad(subreq, req->assoclen + ivsize);

 	scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);

 	return crypto_aead_decrypt(subreq);
 }

 static int seqiv_init(struct crypto_tfm *tfm)
 {
 	struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
 	struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
 	int err;

 	spin_lock_init(&ctx->lock);

 	tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request);

 	err = 0;
 	if (!crypto_get_default_rng()) {
 		crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt;
 		err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 					   crypto_ablkcipher_ivsize(geniv));
 		crypto_put_default_rng();
 	}

 	return err ?: skcipher_geniv_init(tfm);
 }

 static int seqiv_ablkcipher_create(struct crypto_template *tmpl,
 				   struct rtattr **tb)
 {
 	struct crypto_instance *inst;
 	int err;

 	inst = skcipher_geniv_alloc(tmpl, tb, 0, 0);

 	if (IS_ERR(inst))
 		return PTR_ERR(inst);

 	err = -EINVAL;
 	if (inst->alg.cra_ablkcipher.ivsize < sizeof(u64))
 		goto free_inst;

 	inst->alg.cra_init = seqiv_init;
 	inst->alg.cra_exit = skcipher_geniv_exit;

 	inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize;
 	inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx);

 	inst->alg.cra_alignmask |= __alignof__(u32) - 1;

 	err = crypto_register_instance(tmpl, inst);
 	if (err)
 		goto free_inst;

 out:
 	return err;

 free_inst:
 	skcipher_geniv_free(inst);
 	goto out;
 }

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

 	inst = aead_geniv_alloc(tmpl, tb, 0, 0);

 	if (IS_ERR(inst))
 		return PTR_ERR(inst);

 	inst->alg.base.cra_alignmask |= __alignof__(u32) - 1;

 	spawn = aead_instance_ctx(inst);
 	alg = crypto_spawn_aead_alg(spawn);

 	err = -EINVAL;
 	if (inst->alg.ivsize != sizeof(u64))
 		goto free_inst;

 	inst->alg.encrypt = seqiv_aead_encrypt;
 	inst->alg.decrypt = seqiv_aead_decrypt;

 	inst->alg.init = aead_init_geniv;
 	inst->alg.exit = aead_exit_geniv;

 	inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
 	inst->alg.base.cra_ctxsize += inst->alg.ivsize;

 	err = aead_register_instance(tmpl, inst);
 	if (err)
 		goto free_inst;

 out:
 	return err;

 free_inst:
 	aead_geniv_free(inst);
 	goto out;
 }

 static int seqiv_create(struct crypto_template *tmpl, struct rtattr **tb)
 {
 	struct crypto_attr_type *algt;
 	int err;

 	algt = crypto_get_attr_type(tb);
 	if (IS_ERR(algt))
 		return PTR_ERR(algt);

 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
 		err = seqiv_ablkcipher_create(tmpl, tb);
 	else
 		err = seqiv_aead_create(tmpl, tb);

 	return err;
 }

 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(aead_instance(inst));
 }

 static struct crypto_template seqiv_tmpl = {
 	.name = "seqiv",
 	.create = seqiv_create,
 	.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");
 MODULE_ALIAS_CRYPTO("seqiv");
	/*
	* 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/geniv.h>
	#include <crypto/internal/skcipher.h>
	#include <crypto/rng.h>
	#include <crypto/scatterwalk.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_free(struct crypto_instance *inst);

	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_encrypt_complete2(struct aead_request *req, int err)
	{
	struct aead_request *subreq = aead_request_ctx(req);
	struct crypto_aead *geniv;

	if (err == -EINPROGRESS)
	return;

	if (err)
	goto out;

	geniv = crypto_aead_reqtfm(req);
	memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv));

	out:
	kzfree(subreq->iv);
	}

	static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
	int err)
	{
	struct aead_request *req = base->data;

	seqiv_aead_encrypt_complete2(req, err);
	aead_request_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 compl;
	void *data;
	u8 *info;
	unsigned int ivsize;
	int err;

	ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv));

	compl = 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;

	compl = seqiv_complete;
	data = req;
	}

	ablkcipher_request_set_callback(subreq, req->creq.base.flags, compl,
	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_encrypt(struct aead_request *req)
	{
	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
	struct aead_request *subreq = aead_request_ctx(req);
	crypto_completion_t compl;
	void *data;
	u8 *info;
	unsigned int ivsize = 8;
	int err;

	if (req->cryptlen < ivsize)
	return -EINVAL;

	aead_request_set_tfm(subreq, ctx->child);

	compl = req->base.complete;
	data = req->base.data;
	info = req->iv;

	if (req->src != req->dst) {
	struct blkcipher_desc desc = {
	.tfm = ctx->null,
	};

	err = crypto_blkcipher_encrypt(&desc, req->dst, req->src,
	req->assoclen + req->cryptlen);
	if (err)
	return err;
	}

	if (unlikely(!IS_ALIGNED((unsigned long)info,
	crypto_aead_alignmask(geniv) + 1))) {
	info = kmalloc(ivsize, req->base.flags &
	CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
	GFP_ATOMIC);
	if (!info)
	return -ENOMEM;

	memcpy(info, req->iv, ivsize);
	compl = seqiv_aead_encrypt_complete;
	data = req;
	}

	aead_request_set_callback(subreq, req->base.flags, compl, data);
	aead_request_set_crypt(subreq, req->dst, req->dst,
	req->cryptlen - ivsize, info);
	aead_request_set_ad(subreq, req->assoclen + ivsize);

	crypto_xor(info, ctx->salt, ivsize);
	scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);

	err = crypto_aead_encrypt(subreq);
	if (unlikely(info != req->iv))
	seqiv_aead_encrypt_complete2(req, err);
	return err;
	}

	static int seqiv_aead_decrypt(struct aead_request *req)
	{
	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
	struct aead_request *subreq = aead_request_ctx(req);
	crypto_completion_t compl;
	void *data;
	unsigned int ivsize = 8;

	if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
	return -EINVAL;

	aead_request_set_tfm(subreq, ctx->child);

	compl = req->base.complete;
	data = req->base.data;

	aead_request_set_callback(subreq, req->base.flags, compl, data);
	aead_request_set_crypt(subreq, req->src, req->dst,
	req->cryptlen - ivsize, req->iv);
	aead_request_set_ad(subreq, req->assoclen + ivsize);

	scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);

	return crypto_aead_decrypt(subreq);
	}

	static int seqiv_init(struct crypto_tfm *tfm)
	{
	struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
	struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
	int err;

	spin_lock_init(&ctx->lock);

	tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request);

	err = 0;
	if (!crypto_get_default_rng()) {
	crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt;
	err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
	crypto_ablkcipher_ivsize(geniv));
	crypto_put_default_rng();
	}

	return err ?: skcipher_geniv_init(tfm);
	}

	static int seqiv_ablkcipher_create(struct crypto_template *tmpl,
	struct rtattr **tb)
	{
	struct crypto_instance *inst;
	int err;

	inst = skcipher_geniv_alloc(tmpl, tb, 0, 0);

	if (IS_ERR(inst))
	return PTR_ERR(inst);

	err = -EINVAL;
	if (inst->alg.cra_ablkcipher.ivsize < sizeof(u64))
	goto free_inst;

	inst->alg.cra_init = seqiv_init;
	inst->alg.cra_exit = skcipher_geniv_exit;

	inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize;
	inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx);

	inst->alg.cra_alignmask \|= __alignof__(u32) - 1;

	err = crypto_register_instance(tmpl, inst);
	if (err)
	goto free_inst;

	out:
	return err;

	free_inst:
	skcipher_geniv_free(inst);
	goto out;
	}

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

	inst = aead_geniv_alloc(tmpl, tb, 0, 0);

	if (IS_ERR(inst))
	return PTR_ERR(inst);

	inst->alg.base.cra_alignmask \|= __alignof__(u32) - 1;

	spawn = aead_instance_ctx(inst);
	alg = crypto_spawn_aead_alg(spawn);

	err = -EINVAL;
	if (inst->alg.ivsize != sizeof(u64))
	goto free_inst;

	inst->alg.encrypt = seqiv_aead_encrypt;
	inst->alg.decrypt = seqiv_aead_decrypt;

	inst->alg.init = aead_init_geniv;
	inst->alg.exit = aead_exit_geniv;

	inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
	inst->alg.base.cra_ctxsize += inst->alg.ivsize;

	err = aead_register_instance(tmpl, inst);
	if (err)
	goto free_inst;

	out:
	return err;

	free_inst:
	aead_geniv_free(inst);
	goto out;
	}

	static int seqiv_create(struct crypto_template tmpl, struct rtattr *tb)
	{
	struct crypto_attr_type *algt;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
	return PTR_ERR(algt);

	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
	err = seqiv_ablkcipher_create(tmpl, tb);
	else
	err = seqiv_aead_create(tmpl, tb);

	return err;
	}

	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(aead_instance(inst));
	}

	static struct crypto_template seqiv_tmpl = {
	.name = "seqiv",
	.create = seqiv_create,
	.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");
	MODULE_ALIAS_CRYPTO("seqiv");