linux/crypto/seqiv.c

805 lines
19 KiB
C

/*
* 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/null.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 seqniv_request_ctx {
struct scatterlist dst[2];
struct aead_request subreq;
};
struct seqiv_ctx {
spinlock_t lock;
u8 salt[] __attribute__ ((aligned(__alignof__(u32))));
};
struct seqiv_aead_ctx {
/* aead_geniv_ctx must be first the element */
struct aead_geniv_ctx geniv;
struct crypto_blkcipher *null;
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_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_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 seqniv_aead_encrypt_complete2(struct aead_request *req, int err)
{
unsigned int ivsize = 8;
u8 data[20];
if (err == -EINPROGRESS)
return;
/* Swap IV and ESP header back to correct order. */
scatterwalk_map_and_copy(data, req->dst, 0, req->assoclen + ivsize, 0);
scatterwalk_map_and_copy(data + ivsize, req->dst, 0, req->assoclen, 1);
scatterwalk_map_and_copy(data, req->dst, req->assoclen, ivsize, 1);
}
static void seqniv_aead_encrypt_complete(struct crypto_async_request *base,
int err)
{
struct aead_request *req = base->data;
seqniv_aead_encrypt_complete2(req, err);
aead_request_complete(req, err);
}
static void seqniv_aead_decrypt_complete2(struct aead_request *req, int err)
{
u8 data[4];
if (err == -EINPROGRESS)
return;
/* Move ESP header back to correct location. */
scatterwalk_map_and_copy(data, req->dst, 16, req->assoclen - 8, 0);
scatterwalk_map_and_copy(data, req->dst, 8, req->assoclen - 8, 1);
}
static void seqniv_aead_decrypt_complete(struct crypto_async_request *base,
int err)
{
struct aead_request *req = base->data;
seqniv_aead_decrypt_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_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 compl;
void *data;
u8 *info;
unsigned int ivsize;
int err;
aead_request_set_tfm(subreq, aead_geniv_base(geniv));
compl = 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;
compl = seqiv_aead_complete;
data = req;
}
aead_request_set_callback(subreq, areq->base.flags, compl, 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 seqniv_aead_encrypt(struct aead_request *req)
{
struct crypto_aead *geniv = crypto_aead_reqtfm(req);
struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
struct seqniv_request_ctx *rctx = aead_request_ctx(req);
struct aead_request *subreq = &rctx->subreq;
struct scatterlist *dst;
crypto_completion_t compl;
void *data;
unsigned int ivsize = 8;
u8 buf[20] __attribute__ ((aligned(__alignof__(u32))));
int err;
if (req->cryptlen < ivsize)
return -EINVAL;
/* ESP AD is at most 12 bytes (ESN). */
if (req->assoclen > 12)
return -EINVAL;
aead_request_set_tfm(subreq, ctx->geniv.child);
compl = seqniv_aead_encrypt_complete;
data = req;
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;
}
dst = scatterwalk_ffwd(rctx->dst, req->dst, ivsize);
aead_request_set_callback(subreq, req->base.flags, compl, data);
aead_request_set_crypt(subreq, dst, dst,
req->cryptlen - ivsize, req->iv);
aead_request_set_ad(subreq, req->assoclen);
memcpy(buf, req->iv, ivsize);
crypto_xor(buf, ctx->salt, ivsize);
memcpy(req->iv, buf, ivsize);
/* Swap order of IV and ESP AD for ICV generation. */
scatterwalk_map_and_copy(buf + ivsize, req->dst, 0, req->assoclen, 0);
scatterwalk_map_and_copy(buf, req->dst, 0, req->assoclen + ivsize, 1);
err = crypto_aead_encrypt(subreq);
seqniv_aead_encrypt_complete2(req, err);
return err;
}
static int seqiv_aead_encrypt(struct aead_request *req)
{
struct crypto_aead *geniv = crypto_aead_reqtfm(req);
struct seqiv_aead_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->geniv.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 seqniv_aead_decrypt(struct aead_request *req)
{
struct crypto_aead *geniv = crypto_aead_reqtfm(req);
struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
struct seqniv_request_ctx *rctx = aead_request_ctx(req);
struct aead_request *subreq = &rctx->subreq;
struct scatterlist *dst;
crypto_completion_t compl;
void *data;
unsigned int ivsize = 8;
u8 buf[20];
int err;
if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
return -EINVAL;
aead_request_set_tfm(subreq, ctx->geniv.child);
compl = req->base.complete;
data = req->base.data;
if (req->assoclen > 12)
return -EINVAL;
else if (req->assoclen > 8) {
compl = seqniv_aead_decrypt_complete;
data = req;
}
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;
}
/* Move ESP AD forward for ICV generation. */
scatterwalk_map_and_copy(buf, req->dst, 0, req->assoclen + ivsize, 0);
memcpy(req->iv, buf + req->assoclen, ivsize);
scatterwalk_map_and_copy(buf, req->dst, ivsize, req->assoclen, 1);
dst = scatterwalk_ffwd(rctx->dst, req->dst, ivsize);
aead_request_set_callback(subreq, req->base.flags, compl, data);
aead_request_set_crypt(subreq, dst, dst,
req->cryptlen - ivsize, req->iv);
aead_request_set_ad(subreq, req->assoclen);
err = crypto_aead_decrypt(subreq);
if (req->assoclen > 8)
seqniv_aead_decrypt_complete2(req, err);
return err;
}
static int seqiv_aead_decrypt(struct aead_request *req)
{
struct crypto_aead *geniv = crypto_aead_reqtfm(req);
struct seqiv_aead_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->geniv.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);
if (req->src != req->dst)
scatterwalk_map_and_copy(req->iv, req->dst,
req->assoclen, ivsize, 1);
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_old_aead_init(struct crypto_tfm *tfm)
{
struct crypto_aead *geniv = __crypto_aead_cast(tfm);
struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
int err;
spin_lock_init(&ctx->lock);
crypto_aead_set_reqsize(__crypto_aead_cast(tfm),
sizeof(struct aead_request));
err = 0;
if (!crypto_get_default_rng()) {
geniv->givencrypt = seqiv_aead_givencrypt;
err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
crypto_aead_ivsize(geniv));
crypto_put_default_rng();
}
return err ?: aead_geniv_init(tfm);
}
static int seqiv_aead_init_common(struct crypto_tfm *tfm, unsigned int reqsize)
{
struct crypto_aead *geniv = __crypto_aead_cast(tfm);
struct seqiv_aead_ctx *ctx = crypto_aead_ctx(geniv);
int err;
spin_lock_init(&ctx->geniv.lock);
crypto_aead_set_reqsize(geniv, sizeof(struct aead_request));
err = crypto_get_default_rng();
if (err)
goto out;
err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
crypto_aead_ivsize(geniv));
crypto_put_default_rng();
if (err)
goto out;
ctx->null = crypto_get_default_null_skcipher();
err = PTR_ERR(ctx->null);
if (IS_ERR(ctx->null))
goto out;
err = aead_geniv_init(tfm);
if (err)
goto drop_null;
ctx->geniv.child = geniv->child;
geniv->child = geniv;
out:
return err;
drop_null:
crypto_put_default_null_skcipher();
goto out;
}
static int seqiv_aead_init(struct crypto_tfm *tfm)
{
return seqiv_aead_init_common(tfm, sizeof(struct aead_request));
}
static int seqniv_aead_init(struct crypto_tfm *tfm)
{
return seqiv_aead_init_common(tfm, sizeof(struct seqniv_request_ctx));
}
static void seqiv_aead_exit(struct crypto_tfm *tfm)
{
struct seqiv_aead_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_aead(ctx->geniv.child);
crypto_put_default_null_skcipher();
}
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_old_aead_create(struct crypto_template *tmpl,
struct aead_instance *aead)
{
struct crypto_instance *inst = aead_crypto_instance(aead);
int err = -EINVAL;
if (inst->alg.cra_aead.ivsize < sizeof(u64))
goto free_inst;
inst->alg.cra_init = seqiv_old_aead_init;
inst->alg.cra_exit = aead_geniv_exit;
inst->alg.cra_ctxsize = inst->alg.cra_aead.ivsize;
inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx);
err = crypto_register_instance(tmpl, inst);
if (err)
goto free_inst;
out:
return err;
free_inst:
aead_geniv_free(aead);
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;
if (inst->alg.base.cra_aead.encrypt)
return seqiv_old_aead_create(tmpl, inst);
spawn = aead_instance_ctx(inst);
alg = crypto_spawn_aead_alg(spawn);
if (alg->base.cra_aead.encrypt)
goto done;
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.base.cra_init = seqiv_aead_init;
inst->alg.base.cra_exit = seqiv_aead_exit;
inst->alg.base.cra_ctxsize = sizeof(struct seqiv_aead_ctx);
inst->alg.base.cra_ctxsize += inst->alg.base.cra_aead.ivsize;
done:
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 int seqniv_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);
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto out;
spawn = aead_instance_ctx(inst);
alg = crypto_spawn_aead_alg(spawn);
if (alg->base.cra_aead.encrypt)
goto done;
err = -EINVAL;
if (inst->alg.ivsize != sizeof(u64))
goto free_inst;
inst->alg.encrypt = seqniv_aead_encrypt;
inst->alg.decrypt = seqniv_aead_decrypt;
inst->alg.base.cra_init = seqniv_aead_init;
inst->alg.base.cra_exit = seqiv_aead_exit;
inst->alg.base.cra_alignmask |= __alignof__(u32) - 1;
inst->alg.base.cra_ctxsize = sizeof(struct seqiv_aead_ctx);
inst->alg.base.cra_ctxsize += inst->alg.ivsize;
done:
err = aead_register_instance(tmpl, inst);
if (err)
goto free_inst;
out:
return err;
free_inst:
aead_geniv_free(inst);
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(aead_instance(inst));
}
static struct crypto_template seqiv_tmpl = {
.name = "seqiv",
.create = seqiv_create,
.free = seqiv_free,
.module = THIS_MODULE,
};
static struct crypto_template seqniv_tmpl = {
.name = "seqniv",
.create = seqniv_create,
.free = seqiv_free,
.module = THIS_MODULE,
};
static int __init seqiv_module_init(void)
{
int err;
err = crypto_register_template(&seqiv_tmpl);
if (err)
goto out;
err = crypto_register_template(&seqniv_tmpl);
if (err)
goto out_undo_niv;
out:
return err;
out_undo_niv:
crypto_unregister_template(&seqiv_tmpl);
goto out;
}
static void __exit seqiv_module_exit(void)
{
crypto_unregister_template(&seqniv_tmpl);
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");
MODULE_ALIAS_CRYPTO("seqniv");