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![Tim Chen](/assets/img/avatar_default.png)
For the special case when we have a null input string, we want to initialize the entry len to 0 for the hash/ahash walk, so cyrpto_hash_walk_last will return the correct result indicating that we have completed the scatter list walk. Otherwise we may keep walking the sg list and access bogus memory address. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
614 lines
15 KiB
C
614 lines
15 KiB
C
/*
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* Asynchronous Cryptographic Hash operations.
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*
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* This is the asynchronous version of hash.c with notification of
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* completion via a callback.
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*
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* Copyright (c) 2008 Loc Ho <lho@amcc.com>
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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/internal/hash.h>
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#include <crypto/scatterwalk.h>
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#include <linux/bug.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/seq_file.h>
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#include <linux/cryptouser.h>
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#include <net/netlink.h>
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#include "internal.h"
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struct ahash_request_priv {
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crypto_completion_t complete;
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void *data;
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u8 *result;
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void *ubuf[] CRYPTO_MINALIGN_ATTR;
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};
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static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
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{
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return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
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halg);
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}
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static int hash_walk_next(struct crypto_hash_walk *walk)
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{
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unsigned int alignmask = walk->alignmask;
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unsigned int offset = walk->offset;
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unsigned int nbytes = min(walk->entrylen,
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((unsigned int)(PAGE_SIZE)) - offset);
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if (walk->flags & CRYPTO_ALG_ASYNC)
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walk->data = kmap(walk->pg);
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else
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walk->data = kmap_atomic(walk->pg);
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walk->data += offset;
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if (offset & alignmask) {
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unsigned int unaligned = alignmask + 1 - (offset & alignmask);
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if (nbytes > unaligned)
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nbytes = unaligned;
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}
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walk->entrylen -= nbytes;
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return nbytes;
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}
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static int hash_walk_new_entry(struct crypto_hash_walk *walk)
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{
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struct scatterlist *sg;
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sg = walk->sg;
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walk->pg = sg_page(sg);
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walk->offset = sg->offset;
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walk->entrylen = sg->length;
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if (walk->entrylen > walk->total)
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walk->entrylen = walk->total;
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walk->total -= walk->entrylen;
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return hash_walk_next(walk);
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}
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int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
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{
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unsigned int alignmask = walk->alignmask;
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unsigned int nbytes = walk->entrylen;
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walk->data -= walk->offset;
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if (nbytes && walk->offset & alignmask && !err) {
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walk->offset = ALIGN(walk->offset, alignmask + 1);
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walk->data += walk->offset;
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nbytes = min(nbytes,
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((unsigned int)(PAGE_SIZE)) - walk->offset);
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walk->entrylen -= nbytes;
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return nbytes;
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}
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if (walk->flags & CRYPTO_ALG_ASYNC)
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kunmap(walk->pg);
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else {
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kunmap_atomic(walk->data);
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/*
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* The may sleep test only makes sense for sync users.
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* Async users don't need to sleep here anyway.
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*/
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crypto_yield(walk->flags);
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}
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if (err)
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return err;
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if (nbytes) {
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walk->offset = 0;
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walk->pg++;
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return hash_walk_next(walk);
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}
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if (!walk->total)
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return 0;
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walk->sg = scatterwalk_sg_next(walk->sg);
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return hash_walk_new_entry(walk);
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}
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EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
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int crypto_hash_walk_first(struct ahash_request *req,
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struct crypto_hash_walk *walk)
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{
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walk->total = req->nbytes;
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if (!walk->total) {
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walk->entrylen = 0;
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return 0;
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}
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walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
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walk->sg = req->src;
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walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
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return hash_walk_new_entry(walk);
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}
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EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
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int crypto_ahash_walk_first(struct ahash_request *req,
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struct crypto_hash_walk *walk)
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{
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walk->total = req->nbytes;
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if (!walk->total) {
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walk->entrylen = 0;
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return 0;
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}
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walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
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walk->sg = req->src;
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walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
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walk->flags |= CRYPTO_ALG_ASYNC;
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BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
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return hash_walk_new_entry(walk);
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}
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EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
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int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
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struct crypto_hash_walk *walk,
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struct scatterlist *sg, unsigned int len)
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{
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walk->total = len;
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if (!walk->total) {
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walk->entrylen = 0;
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return 0;
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}
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walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
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walk->sg = sg;
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walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK;
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return hash_walk_new_entry(walk);
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}
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static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
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unsigned int keylen)
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{
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unsigned long alignmask = crypto_ahash_alignmask(tfm);
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int ret;
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u8 *buffer, *alignbuffer;
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unsigned long absize;
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absize = keylen + alignmask;
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buffer = kmalloc(absize, GFP_KERNEL);
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if (!buffer)
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return -ENOMEM;
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alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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memcpy(alignbuffer, key, keylen);
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ret = tfm->setkey(tfm, alignbuffer, keylen);
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kzfree(buffer);
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return ret;
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}
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int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
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unsigned int keylen)
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{
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unsigned long alignmask = crypto_ahash_alignmask(tfm);
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if ((unsigned long)key & alignmask)
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return ahash_setkey_unaligned(tfm, key, keylen);
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return tfm->setkey(tfm, key, keylen);
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}
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EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
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static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
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unsigned int keylen)
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{
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return -ENOSYS;
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}
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static inline unsigned int ahash_align_buffer_size(unsigned len,
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unsigned long mask)
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{
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return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
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}
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static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
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{
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struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
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unsigned long alignmask = crypto_ahash_alignmask(tfm);
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unsigned int ds = crypto_ahash_digestsize(tfm);
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struct ahash_request_priv *priv;
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priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
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(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
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GFP_KERNEL : GFP_ATOMIC);
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if (!priv)
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return -ENOMEM;
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/*
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* WARNING: Voodoo programming below!
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*
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* The code below is obscure and hard to understand, thus explanation
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* is necessary. See include/crypto/hash.h and include/linux/crypto.h
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* to understand the layout of structures used here!
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*
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* The code here will replace portions of the ORIGINAL request with
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* pointers to new code and buffers so the hashing operation can store
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* the result in aligned buffer. We will call the modified request
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* an ADJUSTED request.
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*
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* The newly mangled request will look as such:
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*
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* req {
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* .result = ADJUSTED[new aligned buffer]
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* .base.complete = ADJUSTED[pointer to completion function]
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* .base.data = ADJUSTED[*req (pointer to self)]
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* .priv = ADJUSTED[new priv] {
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* .result = ORIGINAL(result)
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* .complete = ORIGINAL(base.complete)
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* .data = ORIGINAL(base.data)
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* }
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*/
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priv->result = req->result;
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priv->complete = req->base.complete;
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priv->data = req->base.data;
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/*
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* WARNING: We do not backup req->priv here! The req->priv
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* is for internal use of the Crypto API and the
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* user must _NOT_ _EVER_ depend on it's content!
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*/
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req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
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req->base.complete = cplt;
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req->base.data = req;
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req->priv = priv;
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return 0;
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}
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static void ahash_restore_req(struct ahash_request *req)
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{
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struct ahash_request_priv *priv = req->priv;
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/* Restore the original crypto request. */
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req->result = priv->result;
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req->base.complete = priv->complete;
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req->base.data = priv->data;
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req->priv = NULL;
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/* Free the req->priv.priv from the ADJUSTED request. */
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kzfree(priv);
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}
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static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
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{
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struct ahash_request_priv *priv = req->priv;
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if (err == -EINPROGRESS)
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return;
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if (!err)
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memcpy(priv->result, req->result,
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crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
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ahash_restore_req(req);
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}
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static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
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{
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struct ahash_request *areq = req->data;
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/*
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* Restore the original request, see ahash_op_unaligned() for what
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* goes where.
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*
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* The "struct ahash_request *req" here is in fact the "req.base"
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* from the ADJUSTED request from ahash_op_unaligned(), thus as it
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* is a pointer to self, it is also the ADJUSTED "req" .
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*/
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/* First copy req->result into req->priv.result */
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ahash_op_unaligned_finish(areq, err);
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/* Complete the ORIGINAL request. */
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areq->base.complete(&areq->base, err);
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}
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static int ahash_op_unaligned(struct ahash_request *req,
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int (*op)(struct ahash_request *))
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{
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int err;
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err = ahash_save_req(req, ahash_op_unaligned_done);
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if (err)
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return err;
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err = op(req);
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ahash_op_unaligned_finish(req, err);
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return err;
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}
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static int crypto_ahash_op(struct ahash_request *req,
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int (*op)(struct ahash_request *))
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{
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struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
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unsigned long alignmask = crypto_ahash_alignmask(tfm);
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if ((unsigned long)req->result & alignmask)
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return ahash_op_unaligned(req, op);
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return op(req);
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}
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int crypto_ahash_final(struct ahash_request *req)
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{
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return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
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}
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EXPORT_SYMBOL_GPL(crypto_ahash_final);
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int crypto_ahash_finup(struct ahash_request *req)
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{
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return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
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}
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EXPORT_SYMBOL_GPL(crypto_ahash_finup);
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int crypto_ahash_digest(struct ahash_request *req)
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{
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return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
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}
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EXPORT_SYMBOL_GPL(crypto_ahash_digest);
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static void ahash_def_finup_finish2(struct ahash_request *req, int err)
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{
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struct ahash_request_priv *priv = req->priv;
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if (err == -EINPROGRESS)
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return;
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if (!err)
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memcpy(priv->result, req->result,
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crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
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ahash_restore_req(req);
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}
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static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
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{
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struct ahash_request *areq = req->data;
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ahash_def_finup_finish2(areq, err);
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areq->base.complete(&areq->base, err);
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}
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static int ahash_def_finup_finish1(struct ahash_request *req, int err)
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{
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if (err)
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goto out;
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req->base.complete = ahash_def_finup_done2;
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req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
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err = crypto_ahash_reqtfm(req)->final(req);
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out:
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ahash_def_finup_finish2(req, err);
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return err;
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}
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static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
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{
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struct ahash_request *areq = req->data;
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err = ahash_def_finup_finish1(areq, err);
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areq->base.complete(&areq->base, err);
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}
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static int ahash_def_finup(struct ahash_request *req)
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{
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struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
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int err;
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err = ahash_save_req(req, ahash_def_finup_done1);
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if (err)
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return err;
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err = tfm->update(req);
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return ahash_def_finup_finish1(req, err);
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}
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static int ahash_no_export(struct ahash_request *req, void *out)
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{
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return -ENOSYS;
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}
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static int ahash_no_import(struct ahash_request *req, const void *in)
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{
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return -ENOSYS;
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}
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static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
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{
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struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
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struct ahash_alg *alg = crypto_ahash_alg(hash);
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hash->setkey = ahash_nosetkey;
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hash->export = ahash_no_export;
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hash->import = ahash_no_import;
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if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
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return crypto_init_shash_ops_async(tfm);
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hash->init = alg->init;
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hash->update = alg->update;
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hash->final = alg->final;
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hash->finup = alg->finup ?: ahash_def_finup;
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hash->digest = alg->digest;
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if (alg->setkey)
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hash->setkey = alg->setkey;
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if (alg->export)
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hash->export = alg->export;
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if (alg->import)
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hash->import = alg->import;
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return 0;
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}
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static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
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{
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if (alg->cra_type == &crypto_ahash_type)
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return alg->cra_ctxsize;
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return sizeof(struct crypto_shash *);
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}
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#ifdef CONFIG_NET
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static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
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{
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struct crypto_report_hash rhash;
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strncpy(rhash.type, "ahash", sizeof(rhash.type));
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rhash.blocksize = alg->cra_blocksize;
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rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
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if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
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sizeof(struct crypto_report_hash), &rhash))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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#else
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static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
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{
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return -ENOSYS;
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}
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#endif
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static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
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__attribute__ ((unused));
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static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
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{
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seq_printf(m, "type : ahash\n");
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seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
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"yes" : "no");
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seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
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seq_printf(m, "digestsize : %u\n",
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__crypto_hash_alg_common(alg)->digestsize);
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}
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const struct crypto_type crypto_ahash_type = {
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.extsize = crypto_ahash_extsize,
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.init_tfm = crypto_ahash_init_tfm,
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#ifdef CONFIG_PROC_FS
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.show = crypto_ahash_show,
|
|
#endif
|
|
.report = crypto_ahash_report,
|
|
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
|
|
.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
|
|
.type = CRYPTO_ALG_TYPE_AHASH,
|
|
.tfmsize = offsetof(struct crypto_ahash, base),
|
|
};
|
|
EXPORT_SYMBOL_GPL(crypto_ahash_type);
|
|
|
|
struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
|
|
u32 mask)
|
|
{
|
|
return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
|
|
|
|
static int ahash_prepare_alg(struct ahash_alg *alg)
|
|
{
|
|
struct crypto_alg *base = &alg->halg.base;
|
|
|
|
if (alg->halg.digestsize > PAGE_SIZE / 8 ||
|
|
alg->halg.statesize > PAGE_SIZE / 8)
|
|
return -EINVAL;
|
|
|
|
base->cra_type = &crypto_ahash_type;
|
|
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
|
|
base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int crypto_register_ahash(struct ahash_alg *alg)
|
|
{
|
|
struct crypto_alg *base = &alg->halg.base;
|
|
int err;
|
|
|
|
err = ahash_prepare_alg(alg);
|
|
if (err)
|
|
return err;
|
|
|
|
return crypto_register_alg(base);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_register_ahash);
|
|
|
|
int crypto_unregister_ahash(struct ahash_alg *alg)
|
|
{
|
|
return crypto_unregister_alg(&alg->halg.base);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
|
|
|
|
int ahash_register_instance(struct crypto_template *tmpl,
|
|
struct ahash_instance *inst)
|
|
{
|
|
int err;
|
|
|
|
err = ahash_prepare_alg(&inst->alg);
|
|
if (err)
|
|
return err;
|
|
|
|
return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
|
|
}
|
|
EXPORT_SYMBOL_GPL(ahash_register_instance);
|
|
|
|
void ahash_free_instance(struct crypto_instance *inst)
|
|
{
|
|
crypto_drop_spawn(crypto_instance_ctx(inst));
|
|
kfree(ahash_instance(inst));
|
|
}
|
|
EXPORT_SYMBOL_GPL(ahash_free_instance);
|
|
|
|
int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
|
|
struct hash_alg_common *alg,
|
|
struct crypto_instance *inst)
|
|
{
|
|
return crypto_init_spawn2(&spawn->base, &alg->base, inst,
|
|
&crypto_ahash_type);
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
|
|
|
|
struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
|
|
{
|
|
struct crypto_alg *alg;
|
|
|
|
alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
|
|
return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ahash_attr_alg);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
|