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![Herbert Xu](/assets/img/avatar_default.png)
This patch implements the givencrypt function for authenc. It simply calls the givencrypt operation on the underlying cipher instead of encrypt. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
488 lines
13 KiB
C
488 lines
13 KiB
C
/*
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* Authenc: Simple AEAD wrapper for IPsec
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*
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* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <crypto/aead.h>
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#include <crypto/internal/skcipher.h>
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#include <crypto/authenc.h>
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#include <crypto/scatterwalk.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/rtnetlink.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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struct authenc_instance_ctx {
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struct crypto_spawn auth;
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struct crypto_skcipher_spawn enc;
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};
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struct crypto_authenc_ctx {
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spinlock_t auth_lock;
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struct crypto_hash *auth;
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struct crypto_ablkcipher *enc;
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};
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static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key,
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unsigned int keylen)
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{
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unsigned int authkeylen;
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unsigned int enckeylen;
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struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
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struct crypto_hash *auth = ctx->auth;
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struct crypto_ablkcipher *enc = ctx->enc;
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struct rtattr *rta = (void *)key;
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struct crypto_authenc_key_param *param;
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int err = -EINVAL;
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if (!RTA_OK(rta, keylen))
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goto badkey;
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if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
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goto badkey;
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if (RTA_PAYLOAD(rta) < sizeof(*param))
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goto badkey;
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param = RTA_DATA(rta);
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enckeylen = be32_to_cpu(param->enckeylen);
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key += RTA_ALIGN(rta->rta_len);
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keylen -= RTA_ALIGN(rta->rta_len);
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if (keylen < enckeylen)
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goto badkey;
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authkeylen = keylen - enckeylen;
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crypto_hash_clear_flags(auth, CRYPTO_TFM_REQ_MASK);
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crypto_hash_set_flags(auth, crypto_aead_get_flags(authenc) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_hash_setkey(auth, key, authkeylen);
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crypto_aead_set_flags(authenc, crypto_hash_get_flags(auth) &
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CRYPTO_TFM_RES_MASK);
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if (err)
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goto out;
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crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK);
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crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen);
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crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) &
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CRYPTO_TFM_RES_MASK);
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out:
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return err;
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badkey:
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crypto_aead_set_flags(authenc, CRYPTO_TFM_RES_BAD_KEY_LEN);
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goto out;
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}
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static void authenc_chain(struct scatterlist *head, struct scatterlist *sg,
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int chain)
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{
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if (chain) {
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head->length += sg->length;
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sg = scatterwalk_sg_next(sg);
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}
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if (sg)
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scatterwalk_sg_chain(head, 2, sg);
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else
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sg_mark_end(head);
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}
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static u8 *crypto_authenc_hash(struct aead_request *req, unsigned int flags,
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struct scatterlist *cipher,
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unsigned int cryptlen)
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{
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struct crypto_aead *authenc = crypto_aead_reqtfm(req);
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struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
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struct crypto_hash *auth = ctx->auth;
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struct hash_desc desc = {
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.tfm = auth,
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.flags = aead_request_flags(req) & flags,
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};
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u8 *hash = aead_request_ctx(req);
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int err;
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hash = (u8 *)ALIGN((unsigned long)hash + crypto_hash_alignmask(auth),
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crypto_hash_alignmask(auth) + 1);
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spin_lock_bh(&ctx->auth_lock);
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err = crypto_hash_init(&desc);
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if (err)
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goto auth_unlock;
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err = crypto_hash_update(&desc, req->assoc, req->assoclen);
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if (err)
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goto auth_unlock;
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err = crypto_hash_update(&desc, cipher, cryptlen);
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if (err)
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goto auth_unlock;
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err = crypto_hash_final(&desc, hash);
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auth_unlock:
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spin_unlock_bh(&ctx->auth_lock);
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if (err)
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return ERR_PTR(err);
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return hash;
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}
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static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
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unsigned int flags)
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{
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struct crypto_aead *authenc = crypto_aead_reqtfm(req);
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struct scatterlist *dst = req->dst;
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struct scatterlist cipher[2];
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struct page *dstp;
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unsigned int ivsize = crypto_aead_ivsize(authenc);
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unsigned int cryptlen;
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u8 *vdst;
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u8 *hash;
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dstp = sg_page(dst);
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vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
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sg_init_table(cipher, 2);
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sg_set_buf(cipher, iv, ivsize);
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authenc_chain(cipher, dst, vdst == iv + ivsize);
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cryptlen = req->cryptlen + ivsize;
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hash = crypto_authenc_hash(req, flags, cipher, cryptlen);
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if (IS_ERR(hash))
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return PTR_ERR(hash);
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scatterwalk_map_and_copy(hash, cipher, cryptlen,
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crypto_aead_authsize(authenc), 1);
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return 0;
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}
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static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
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int err)
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{
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if (!err) {
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struct aead_request *areq = req->data;
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struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
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struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
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struct ablkcipher_request *abreq = aead_request_ctx(areq);
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u8 *iv = (u8 *)(abreq + 1) +
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crypto_ablkcipher_reqsize(ctx->enc);
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err = crypto_authenc_genicv(areq, iv, 0);
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}
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aead_request_complete(req->data, err);
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}
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static int crypto_authenc_encrypt(struct aead_request *req)
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{
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struct crypto_aead *authenc = crypto_aead_reqtfm(req);
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struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
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struct ablkcipher_request *abreq = aead_request_ctx(req);
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struct crypto_ablkcipher *enc = ctx->enc;
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struct scatterlist *dst = req->dst;
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unsigned int cryptlen = req->cryptlen;
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u8 *iv = (u8 *)(abreq + 1) + crypto_ablkcipher_reqsize(enc);
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int err;
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ablkcipher_request_set_tfm(abreq, enc);
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ablkcipher_request_set_callback(abreq, aead_request_flags(req),
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crypto_authenc_encrypt_done, req);
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ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
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memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
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err = crypto_ablkcipher_encrypt(abreq);
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if (err)
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return err;
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return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
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}
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static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
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int err)
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{
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if (!err) {
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struct aead_givcrypt_request *greq = req->data;
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err = crypto_authenc_genicv(&greq->areq, greq->giv, 0);
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}
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aead_request_complete(req->data, err);
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}
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static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
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{
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struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
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struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
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struct aead_request *areq = &req->areq;
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struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
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u8 *iv = req->giv;
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int err;
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skcipher_givcrypt_set_tfm(greq, ctx->enc);
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skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
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crypto_authenc_givencrypt_done, areq);
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skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
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areq->iv);
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skcipher_givcrypt_set_giv(greq, iv, req->seq);
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err = crypto_skcipher_givencrypt(greq);
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if (err)
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return err;
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return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
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}
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static int crypto_authenc_verify(struct aead_request *req,
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struct scatterlist *cipher,
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unsigned int cryptlen)
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{
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struct crypto_aead *authenc = crypto_aead_reqtfm(req);
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u8 *ohash;
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u8 *ihash;
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unsigned int authsize;
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ohash = crypto_authenc_hash(req, CRYPTO_TFM_REQ_MAY_SLEEP, cipher,
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cryptlen);
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if (IS_ERR(ohash))
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return PTR_ERR(ohash);
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authsize = crypto_aead_authsize(authenc);
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ihash = ohash + authsize;
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scatterwalk_map_and_copy(ihash, cipher, cryptlen, authsize, 0);
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return memcmp(ihash, ohash, authsize) ? -EBADMSG: 0;
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}
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static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
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unsigned int cryptlen)
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{
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struct crypto_aead *authenc = crypto_aead_reqtfm(req);
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struct scatterlist *src = req->src;
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struct scatterlist cipher[2];
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struct page *srcp;
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unsigned int ivsize = crypto_aead_ivsize(authenc);
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u8 *vsrc;
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srcp = sg_page(src);
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vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
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sg_init_table(cipher, 2);
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sg_set_buf(cipher, iv, ivsize);
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authenc_chain(cipher, src, vsrc == iv + ivsize);
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return crypto_authenc_verify(req, cipher, cryptlen + ivsize);
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}
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static int crypto_authenc_decrypt(struct aead_request *req)
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{
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struct crypto_aead *authenc = crypto_aead_reqtfm(req);
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struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
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struct ablkcipher_request *abreq = aead_request_ctx(req);
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unsigned int cryptlen = req->cryptlen;
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unsigned int authsize = crypto_aead_authsize(authenc);
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u8 *iv = req->iv;
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int err;
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if (cryptlen < authsize)
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return -EINVAL;
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cryptlen -= authsize;
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err = crypto_authenc_iverify(req, iv, cryptlen);
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if (err)
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return err;
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ablkcipher_request_set_tfm(abreq, ctx->enc);
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ablkcipher_request_set_callback(abreq, aead_request_flags(req),
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req->base.complete, req->base.data);
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ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
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return crypto_ablkcipher_decrypt(abreq);
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}
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static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
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{
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struct crypto_instance *inst = (void *)tfm->__crt_alg;
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struct authenc_instance_ctx *ictx = crypto_instance_ctx(inst);
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struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
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struct crypto_hash *auth;
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struct crypto_ablkcipher *enc;
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int err;
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auth = crypto_spawn_hash(&ictx->auth);
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if (IS_ERR(auth))
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return PTR_ERR(auth);
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enc = crypto_spawn_skcipher(&ictx->enc);
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err = PTR_ERR(enc);
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if (IS_ERR(enc))
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goto err_free_hash;
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ctx->auth = auth;
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ctx->enc = enc;
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tfm->crt_aead.reqsize = max_t(unsigned int,
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(crypto_hash_alignmask(auth) &
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~(crypto_tfm_ctx_alignment() - 1)) +
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crypto_hash_digestsize(auth) * 2,
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sizeof(struct skcipher_givcrypt_request) +
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crypto_ablkcipher_reqsize(enc) +
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crypto_ablkcipher_ivsize(enc));
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spin_lock_init(&ctx->auth_lock);
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return 0;
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err_free_hash:
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crypto_free_hash(auth);
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return err;
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}
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static void crypto_authenc_exit_tfm(struct crypto_tfm *tfm)
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{
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struct crypto_authenc_ctx *ctx = crypto_tfm_ctx(tfm);
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crypto_free_hash(ctx->auth);
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crypto_free_ablkcipher(ctx->enc);
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}
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static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
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{
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struct crypto_attr_type *algt;
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struct crypto_instance *inst;
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struct crypto_alg *auth;
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struct crypto_alg *enc;
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struct authenc_instance_ctx *ctx;
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const char *enc_name;
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int err;
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algt = crypto_get_attr_type(tb);
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err = PTR_ERR(algt);
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if (IS_ERR(algt))
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return ERR_PTR(err);
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if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
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return ERR_PTR(-EINVAL);
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auth = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_HASH,
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CRYPTO_ALG_TYPE_HASH_MASK);
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if (IS_ERR(auth))
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return ERR_PTR(PTR_ERR(auth));
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enc_name = crypto_attr_alg_name(tb[2]);
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err = PTR_ERR(enc_name);
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if (IS_ERR(enc_name))
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goto out_put_auth;
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inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
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err = -ENOMEM;
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if (!inst)
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goto out_put_auth;
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ctx = crypto_instance_ctx(inst);
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err = crypto_init_spawn(&ctx->auth, auth, inst, CRYPTO_ALG_TYPE_MASK);
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if (err)
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goto err_free_inst;
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crypto_set_skcipher_spawn(&ctx->enc, inst);
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err = crypto_grab_skcipher(&ctx->enc, enc_name, 0,
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crypto_requires_sync(algt->type,
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algt->mask));
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if (err)
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goto err_drop_auth;
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enc = crypto_skcipher_spawn_alg(&ctx->enc);
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err = -ENAMETOOLONG;
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if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
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"authenc(%s,%s)", auth->cra_name, enc->cra_name) >=
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CRYPTO_MAX_ALG_NAME)
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goto err_drop_enc;
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if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
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"authenc(%s,%s)", auth->cra_driver_name,
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enc->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
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goto err_drop_enc;
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inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
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inst->alg.cra_flags |= enc->cra_flags & CRYPTO_ALG_ASYNC;
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inst->alg.cra_priority = enc->cra_priority * 10 + auth->cra_priority;
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inst->alg.cra_blocksize = enc->cra_blocksize;
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inst->alg.cra_alignmask = auth->cra_alignmask | enc->cra_alignmask;
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inst->alg.cra_type = &crypto_aead_type;
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inst->alg.cra_aead.ivsize = enc->cra_ablkcipher.ivsize;
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inst->alg.cra_aead.maxauthsize = auth->cra_type == &crypto_hash_type ?
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auth->cra_hash.digestsize :
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auth->cra_digest.dia_digestsize;
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inst->alg.cra_ctxsize = sizeof(struct crypto_authenc_ctx);
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inst->alg.cra_init = crypto_authenc_init_tfm;
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inst->alg.cra_exit = crypto_authenc_exit_tfm;
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inst->alg.cra_aead.setkey = crypto_authenc_setkey;
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inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
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inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
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inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
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out:
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crypto_mod_put(auth);
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return inst;
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err_drop_enc:
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crypto_drop_skcipher(&ctx->enc);
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err_drop_auth:
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crypto_drop_spawn(&ctx->auth);
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err_free_inst:
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kfree(inst);
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out_put_auth:
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inst = ERR_PTR(err);
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goto out;
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}
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static void crypto_authenc_free(struct crypto_instance *inst)
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{
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struct authenc_instance_ctx *ctx = crypto_instance_ctx(inst);
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crypto_drop_skcipher(&ctx->enc);
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crypto_drop_spawn(&ctx->auth);
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kfree(inst);
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}
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static struct crypto_template crypto_authenc_tmpl = {
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.name = "authenc",
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.alloc = crypto_authenc_alloc,
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.free = crypto_authenc_free,
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.module = THIS_MODULE,
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};
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static int __init crypto_authenc_module_init(void)
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{
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return crypto_register_template(&crypto_authenc_tmpl);
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}
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|
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static void __exit crypto_authenc_module_exit(void)
|
|
{
|
|
crypto_unregister_template(&crypto_authenc_tmpl);
|
|
}
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|
|
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module_init(crypto_authenc_module_init);
|
|
module_exit(crypto_authenc_module_exit);
|
|
|
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Simple AEAD wrapper for IPsec");
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