/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- crypto_authenc_setkey
- authenc_chain
- crypto_authenc_hash
- crypto_authenc_genicv
- crypto_authenc_encrypt_done
- crypto_authenc_encrypt
- crypto_authenc_givencrypt_done
- crypto_authenc_givencrypt
- crypto_authenc_verify
- crypto_authenc_iverify
- crypto_authenc_decrypt
- crypto_authenc_init_tfm
- crypto_authenc_exit_tfm
- crypto_authenc_alloc
- crypto_authenc_free
- crypto_authenc_module_init
- crypto_authenc_module_exit
/*
* Authenc: Simple AEAD wrapper for IPsec
*
* 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/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/authenc.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
struct authenc_instance_ctx {
struct crypto_spawn auth;
struct crypto_skcipher_spawn enc;
};
struct crypto_authenc_ctx {
spinlock_t auth_lock;
struct crypto_hash *auth;
struct crypto_ablkcipher *enc;
};
static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
unsigned int keylen)
{
unsigned int authkeylen;
unsigned int enckeylen;
struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
struct crypto_hash *auth = ctx->auth;
struct crypto_ablkcipher *enc = ctx->enc;
struct rtattr *rta = (void *)key;
struct crypto_authenc_key_param *param;
int err = -EINVAL;
if (!RTA_OK(rta, keylen))
goto badkey;
if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
goto badkey;
if (RTA_PAYLOAD(rta) < sizeof(*param))
goto badkey;
param = RTA_DATA(rta);
enckeylen = be32_to_cpu(param->enckeylen);
key += RTA_ALIGN(rta->rta_len);
keylen -= RTA_ALIGN(rta->rta_len);
if (keylen < enckeylen)
goto badkey;
authkeylen = keylen - enckeylen;
crypto_hash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
crypto_hash_set_flags(auth, crypto_aead_get_flags(authenc) &
CRYPTO_TFM_REQ_MASK);
err = crypto_hash_setkey(auth, key, authkeylen);
crypto_aead_set_flags(authenc, crypto_hash_get_flags(auth) &
CRYPTO_TFM_RES_MASK);
if (err)
goto out;
crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
CRYPTO_TFM_REQ_MASK);
err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
CRYPTO_TFM_RES_MASK);
out:
return err;
badkey:
crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
goto out;
}
static void authenc_chain(struct scatterlist *head, struct scatterlist *sg,
int chain)
{
if (chain) {
head->length += sg->length;
sg = scatterwalk_sg_next(sg);
}
if (sg)
scatterwalk_sg_chain(head, 2, sg);
else
sg_mark_end(head);
}
static u8 *crypto_authenc_hash(struct aead_request *req, unsigned int flags,
struct scatterlist *cipher,
unsigned int cryptlen)
{
struct crypto_aead *authenc = crypto_aead_reqtfm(req);
struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
struct crypto_hash *auth = ctx->auth;
struct hash_desc desc = {
.tfm = auth,
.flags = aead_request_flags(req) & flags,
};
u8 *hash = aead_request_ctx(req);
int err;
hash = (u8 *)ALIGN((unsigned long)hash + crypto_hash_alignmask(auth),
crypto_hash_alignmask(auth) + 1);
spin_lock_bh(&ctx->auth_lock);
err = crypto_hash_init(&desc);
if (err)
goto auth_unlock;
err = crypto_hash_update(&desc, req->assoc, req->assoclen);
if (err)
goto auth_unlock;
err = crypto_hash_update(&desc, cipher, cryptlen);
if (err)
goto auth_unlock;
err = crypto_hash_final(&desc, hash);
auth_unlock:
spin_unlock_bh(&ctx->auth_lock);
if (err)
return ERR_PTR(err);
return hash;
}
static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
unsigned int flags)
{
struct crypto_aead *authenc = crypto_aead_reqtfm(req);
struct scatterlist *dst = req->dst;
struct scatterlist cipher[2];
struct page *dstp;
unsigned int ivsize = crypto_aead_ivsize(authenc);
unsigned int cryptlen;
u8 *vdst;
u8 *hash;
dstp = sg_page(dst);
vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
sg_init_table(cipher, 2);
sg_set_buf(cipher, iv, ivsize);
authenc_chain(cipher, dst, vdst == iv + ivsize);
cryptlen = req->cryptlen + ivsize;
hash = crypto_authenc_hash(req, flags, cipher, cryptlen);
if (IS_ERR(hash))
return PTR_ERR(hash);
scatterwalk_map_and_copy(hash, cipher, cryptlen,
crypto_aead_authsize(authenc), 1);
return 0;
}
static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
int err)
{
struct aead_request *areq = req->data;
if (!err) {
struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
struct ablkcipher_request *abreq = aead_request_ctx(areq);
u8 *iv = (u8 *)(abreq + 1) +
crypto_ablkcipher_reqsize(ctx->enc);
err = crypto_authenc_genicv(areq, iv, 0);
}
aead_request_complete(areq, err);
}
static int crypto_authenc_encrypt(struct aead_request *req)
{
struct crypto_aead *authenc = crypto_aead_reqtfm(req);
struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
struct ablkcipher_request *abreq = aead_request_ctx(req);
struct crypto_ablkcipher *enc = ctx->enc;
struct scatterlist *dst = req->dst;
unsigned int cryptlen = req->cryptlen;
u8 *iv = (u8 *)(abreq + 1) + crypto_ablkcipher_reqsize(enc);
int err;
ablkcipher_request_set_tfm(abreq, enc);
ablkcipher_request_set_callback(abreq, aead_request_flags(req),
crypto_authenc_encrypt_done, req);
ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
err = crypto_ablkcipher_encrypt(abreq);
if (err)
return err;
return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
}
static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
int err)
{
struct aead_request *areq = req->data;
if (!err) {
struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
err = crypto_authenc_genicv(areq, greq->giv, 0);
}
aead_request_complete(areq, err);
}
static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
{
struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
struct aead_request *areq = &req->areq;
struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
u8 *iv = req->giv;
int err;
skcipher_givcrypt_set_tfm(greq, ctx->enc);
skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
crypto_authenc_givencrypt_done, areq);
skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
areq->iv);
skcipher_givcrypt_set_giv(greq, iv, req->seq);
err = crypto_skcipher_givencrypt(greq);
if (err)
return err;
return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
}
static int crypto_authenc_verify(struct aead_request *req,
struct scatterlist *cipher,
unsigned int cryptlen)
{
struct crypto_aead *authenc = crypto_aead_reqtfm(req);
u8 *ohash;
u8 *ihash;
unsigned int authsize;
ohash = crypto_authenc_hash(req, CRYPTO_TFM_REQ_MAY_SLEEP, cipher,
cryptlen);
if (IS_ERR(ohash))
return PTR_ERR(ohash);
authsize = crypto_aead_authsize(authenc);
ihash = ohash + authsize;
scatterwalk_map_and_copy(ihash, cipher, cryptlen, authsize, 0);
return memcmp(ihash, ohash, authsize) ? -EBADMSG: 0;
}
static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
unsigned int cryptlen)
{
struct crypto_aead *authenc = crypto_aead_reqtfm(req);
struct scatterlist *src = req->src;
struct scatterlist cipher[2];
struct page *srcp;
unsigned int ivsize = crypto_aead_ivsize(authenc);
u8 *vsrc;
srcp = sg_page(src);
vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
sg_init_table(cipher, 2);
sg_set_buf(cipher, iv, ivsize);
authenc_chain(cipher, src, vsrc == iv + ivsize);
return crypto_authenc_verify(req, cipher, cryptlen + ivsize);
}
static int crypto_authenc_decrypt(struct aead_request *req)
{
struct crypto_aead *authenc = crypto_aead_reqtfm(req);
struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
struct ablkcipher_request *abreq = aead_request_ctx(req);
unsigned int cryptlen = req->cryptlen;
unsigned int authsize = crypto_aead_authsize(authenc);
u8 *iv = req->iv;
int err;
if (cryptlen < authsize)
return -EINVAL;
cryptlen -= authsize;
err = crypto_authenc_iverify(req, iv, cryptlen);
if (err)
return err;
ablkcipher_request_set_tfm(abreq, ctx->enc);
ablkcipher_request_set_callback(abreq, aead_request_flags(req),
req->base.complete, req->base.data);
ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
return crypto_ablkcipher_decrypt(abreq);
}
static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_hash *auth;
struct crypto_ablkcipher *enc;
int err;
auth = crypto_spawn_hash(&ictx->auth);
if (IS_ERR(auth))
return PTR_ERR(auth);
enc = crypto_spawn_skcipher(&ictx->enc);
err = PTR_ERR(enc);
if (IS_ERR(enc))
goto err_free_hash;
ctx->auth = auth;
ctx->enc = enc;
tfm->crt_aead.reqsize = max_t(unsigned int,
(crypto_hash_alignmask(auth) &
~(crypto_tfm_ctx_alignment() - 1)) +
crypto_hash_digestsize(auth) * 2,
sizeof(struct skcipher_givcrypt_request) +
crypto_ablkcipher_reqsize(enc) +
crypto_ablkcipher_ivsize(enc));
spin_lock_init(&ctx->auth_lock);
return 0;
err_free_hash:
crypto_free_hash(auth);
return err;
}
static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_hash(ctx->auth);
crypto_free_ablkcipher(ctx->enc);
}
static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
{
struct crypto_attr_type *algt;
struct crypto_instance *inst;
struct crypto_alg *auth;
struct crypto_alg *enc;
struct authenc_instance_ctx *ctx;
const char *enc_name;
int err;
algt = crypto_get_attr_type(tb);
err = PTR_ERR(algt);
if (IS_ERR(algt))
return ERR_PTR(err);
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return ERR_PTR(-EINVAL);
auth = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
CRYPTO_ALG_TYPE_HASH_MASK);
if (IS_ERR(auth))
return ERR_PTR(PTR_ERR(auth));
enc_name = crypto_attr_alg_name(tb[2]);
err = PTR_ERR(enc_name);
if (IS_ERR(enc_name))
goto out_put_auth;
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
err = -ENOMEM;
if (!inst)
goto out_put_auth;
ctx = crypto_instance_ctx(inst);
err = crypto_init_spawn(&ctx->auth, auth, inst, CRYPTO_ALG_TYPE_MASK);
if (err)
goto err_free_inst;
crypto_set_skcipher_spawn(&ctx->enc, inst);
err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
crypto_requires_sync(algt->type,
algt->mask));
if (err)
goto err_drop_auth;
enc = crypto_skcipher_spawn_alg(&ctx->enc);
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
"authenc(%s,%s)", auth->cra_name, enc->cra_name) >=
CRYPTO_MAX_ALG_NAME)
goto err_drop_enc;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"authenc(%s,%s)", auth->cra_driver_name,
enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto err_drop_enc;
inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.cra_priority = enc->cra_priority * 10 + auth->cra_priority;
inst->alg.cra_blocksize = enc->cra_blocksize;
inst->alg.cra_alignmask = auth->cra_alignmask | enc->cra_alignmask;
inst->alg.cra_type = &crypto_aead_type;
inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
inst->alg.cra_aead.maxauthsize = auth->cra_type == &crypto_hash_type ?
auth->cra_hash.digestsize :
auth->cra_digest.dia_digestsize;
inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
inst->alg.cra_init = crypto_authenc_init_tfm;
inst->alg.cra_exit = crypto_authenc_exit_tfm;
inst->alg.cra_aead.setkey = crypto_authenc_setkey;
inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
out:
crypto_mod_put(auth);
return inst;
err_drop_enc:
crypto_drop_skcipher(&ctx->enc);
err_drop_auth:
crypto_drop_spawn(&ctx->auth);
err_free_inst:
kfree(inst);
out_put_auth:
inst = ERR_PTR(err);
goto out;
}
static void crypto_authenc_free(struct crypto_instance *inst)
{
struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
crypto_drop_skcipher(&ctx->enc);
crypto_drop_spawn(&ctx->auth);
kfree(inst);
}
static struct crypto_template crypto_authenc_tmpl = {
.name = "authenc",
.alloc = crypto_authenc_alloc,
.free = crypto_authenc_free,
.module = THIS_MODULE,
};
static int __init crypto_authenc_module_init(void)
{
return crypto_register_template(&crypto_authenc_tmpl);
}
static void __exit crypto_authenc_module_exit(void)
{
crypto_unregister_template(&crypto_authenc_tmpl);
}
module_init(crypto_authenc_module_init);
module_exit(crypto_authenc_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");