diff options
Diffstat (limited to 'crypto/ablkcipher.c')
| -rw-r--r-- | crypto/ablkcipher.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c index fe980dae1727..98a66103f4f2 100644 --- a/crypto/ablkcipher.c +++ b/crypto/ablkcipher.c @@ -24,10 +24,287 @@ #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) { |