/*
* Asynchronous block chaining cipher operations.
- *
+ *
* This is the asynchronous version of blkcipher.c indicating completion
* via a callback.
*
*
* 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)
+ * Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <linux/slab.h>
#include <linux/seq_file.h>
+#include <crypto/scatterwalk.h>
+
#include "internal.h"
static const char *skcipher_default_geniv __read_mostly;
+struct ablkcipher_buffer {
+ struct list_head entry;
+ struct scatter_walk dst;
+ unsigned int len;
+ void *data;
+};
+
+enum {
+ ABLKCIPHER_WALK_SLOW = 1 << 0,
+};
+
+static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
+{
+ scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
+}
+
+void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
+{
+ struct ablkcipher_buffer *p, *tmp;
+
+ list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
+ ablkcipher_buffer_write(p);
+ list_del(&p->entry);
+ kfree(p);
+ }
+}
+EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
+
+static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
+ struct ablkcipher_buffer *p)
+{
+ p->dst = walk->out;
+ list_add_tail(&p->entry, &walk->buffers);
+}
+
+/* Get a spot of the specified length that does not straddle a page.
+ * The caller needs to ensure that there is enough space for this operation.
+ */
+static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
+{
+ u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
+ return max(start, end_page);
+}
+
+static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
+ unsigned int bsize)
+{
+ unsigned int n = bsize;
+
+ for (;;) {
+ unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
+
+ if (len_this_page > n)
+ len_this_page = n;
+ scatterwalk_advance(&walk->out, n);
+ if (n == len_this_page)
+ break;
+ n -= len_this_page;
+ scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
+ }
+
+ return bsize;
+}
+
+static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
+ unsigned int n)
+{
+ scatterwalk_advance(&walk->in, n);
+ scatterwalk_advance(&walk->out, n);
+
+ return n;
+}
+
+static int ablkcipher_walk_next(struct ablkcipher_request *req,
+ struct ablkcipher_walk *walk);
+
+int ablkcipher_walk_done(struct ablkcipher_request *req,
+ struct ablkcipher_walk *walk, int err)
+{
+ struct crypto_tfm *tfm = req->base.tfm;
+ unsigned int nbytes = 0;
+
+ if (likely(err >= 0)) {
+ unsigned int n = walk->nbytes - err;
+
+ if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
+ n = ablkcipher_done_fast(walk, n);
+ else if (WARN_ON(err)) {
+ err = -EINVAL;
+ goto err;
+ } else
+ n = ablkcipher_done_slow(walk, n);
+
+ nbytes = walk->total - n;
+ err = 0;
+ }
+
+ scatterwalk_done(&walk->in, 0, nbytes);
+ scatterwalk_done(&walk->out, 1, nbytes);
+
+err:
+ walk->total = nbytes;
+ walk->nbytes = nbytes;
+
+ if (nbytes) {
+ crypto_yield(req->base.flags);
+ return ablkcipher_walk_next(req, walk);
+ }
+
+ if (walk->iv != req->info)
+ memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
+ if (walk->iv_buffer)
+ kfree(walk->iv_buffer);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
+
+static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
+ struct ablkcipher_walk *walk,
+ unsigned int bsize,
+ unsigned int alignmask,
+ void **src_p, void **dst_p)
+{
+ unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
+ struct ablkcipher_buffer *p;
+ void *src, *dst, *base;
+ unsigned int n;
+
+ n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
+ n += (aligned_bsize * 3 - (alignmask + 1) +
+ (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
+
+ p = kmalloc(n, GFP_ATOMIC);
+ if (!p)
+ ablkcipher_walk_done(req, walk, -ENOMEM);
+
+ base = p + 1;
+
+ dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
+ src = dst = ablkcipher_get_spot(dst, bsize);
+
+ p->len = bsize;
+ p->data = dst;
+
+ scatterwalk_copychunks(src, &walk->in, bsize, 0);
+
+ ablkcipher_queue_write(walk, p);
+
+ walk->nbytes = bsize;
+ walk->flags |= ABLKCIPHER_WALK_SLOW;
+
+ *src_p = src;
+ *dst_p = dst;
+
+ return 0;
+}
+
+static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
+ struct crypto_tfm *tfm,
+ unsigned int alignmask)
+{
+ unsigned bs = walk->blocksize;
+ unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
+ unsigned aligned_bs = ALIGN(bs, alignmask + 1);
+ unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
+ (alignmask + 1);
+ u8 *iv;
+
+ size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
+ walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
+ if (!walk->iv_buffer)
+ return -ENOMEM;
+
+ iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
+ iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
+ iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
+ iv = ablkcipher_get_spot(iv, ivsize);
+
+ walk->iv = memcpy(iv, walk->iv, ivsize);
+ return 0;
+}
+
+static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
+ struct ablkcipher_walk *walk)
+{
+ walk->src.page = scatterwalk_page(&walk->in);
+ walk->src.offset = offset_in_page(walk->in.offset);
+ walk->dst.page = scatterwalk_page(&walk->out);
+ walk->dst.offset = offset_in_page(walk->out.offset);
+
+ return 0;
+}
+
+static int ablkcipher_walk_next(struct ablkcipher_request *req,
+ struct ablkcipher_walk *walk)
+{
+ struct crypto_tfm *tfm = req->base.tfm;
+ unsigned int alignmask, bsize, n;
+ void *src, *dst;
+ int err;
+
+ alignmask = crypto_tfm_alg_alignmask(tfm);
+ n = walk->total;
+ if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
+ req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
+ return ablkcipher_walk_done(req, walk, -EINVAL);
+ }
+
+ walk->flags &= ~ABLKCIPHER_WALK_SLOW;
+ src = dst = NULL;
+
+ bsize = min(walk->blocksize, n);
+ n = scatterwalk_clamp(&walk->in, n);
+ n = scatterwalk_clamp(&walk->out, n);
+
+ if (n < bsize ||
+ !scatterwalk_aligned(&walk->in, alignmask) ||
+ !scatterwalk_aligned(&walk->out, alignmask)) {
+ err = ablkcipher_next_slow(req, walk, bsize, alignmask,
+ &src, &dst);
+ goto set_phys_lowmem;
+ }
+
+ walk->nbytes = n;
+
+ return ablkcipher_next_fast(req, walk);
+
+set_phys_lowmem:
+ if (err >= 0) {
+ walk->src.page = virt_to_page(src);
+ walk->dst.page = virt_to_page(dst);
+ walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
+ walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
+ }
+
+ return err;
+}
+
+static int ablkcipher_walk_first(struct ablkcipher_request *req,
+ struct ablkcipher_walk *walk)
+{
+ struct crypto_tfm *tfm = req->base.tfm;
+ unsigned int alignmask;
+
+ alignmask = crypto_tfm_alg_alignmask(tfm);
+ if (WARN_ON_ONCE(in_irq()))
+ return -EDEADLK;
+
+ walk->nbytes = walk->total;
+ if (unlikely(!walk->total))
+ return 0;
+
+ walk->iv_buffer = NULL;
+ walk->iv = req->info;
+ if (unlikely(((unsigned long)walk->iv & alignmask))) {
+ int err = ablkcipher_copy_iv(walk, tfm, alignmask);
+ if (err)
+ return err;
+ }
+
+ scatterwalk_start(&walk->in, walk->in.sg);
+ scatterwalk_start(&walk->out, walk->out.sg);
+
+ return ablkcipher_walk_next(req, walk);
+}
+
+int ablkcipher_walk_phys(struct ablkcipher_request *req,
+ struct ablkcipher_walk *walk)
+{
+ walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
+ return ablkcipher_walk_first(req, walk);
+}
+EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
+
static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
unsigned int keylen)
{
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff