linux/crypto/seqiv.c
Herbert Xu eeee12aa34 crypto: seqiv - Add compatibility support without RNG
When seqiv is used in compatibility mode, this patch allows it
to function even when an RNG Is not available.  It also changes
the RNG allocation for the new explicit seqiv interface so that
we only hold a reference to the RNG during initialisation.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-22 15:49:28 +08:00

804 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");