From: Herbert Xu Subject: [v2 PATCH 1/16] crypto: skcipher - Add skcipher walk interface Date: Sun, 13 Nov 2016 19:45:32 +0800 Message-ID: References: <20161113114354.GA8169@gondor.apana.org.au> To: Linux Crypto Mailing List Return-path: Received: from helcar.hengli.com.au ([209.40.204.226]:58084 "EHLO helcar.hengli.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933584AbcKMLpk (ORCPT ); Sun, 13 Nov 2016 06:45:40 -0500 Received: from gondolin.me.apana.org.au ([192.168.0.6]) by norbury.hengli.com.au with esmtp (Exim 4.80 #3 (Debian)) id 1c5tE4-0007AG-Fd for ; Sun, 13 Nov 2016 22:45:32 +1100 Sender: linux-crypto-owner@vger.kernel.org List-ID: This patch adds the skcipher walk interface which replaces both blkcipher walk and ablkcipher walk. Just like blkcipher walk it can also be used for AEAD algorithms. Signed-off-by: Herbert Xu --- crypto/skcipher.c | 515 +++++++++++++++++++++++++++++++++++++ include/crypto/internal/skcipher.h | 47 +++ 2 files changed, 562 insertions(+) diff --git a/crypto/skcipher.c b/crypto/skcipher.c index f7d0018..92d8f95 100644 --- a/crypto/skcipher.c +++ b/crypto/skcipher.c @@ -14,9 +14,12 @@ * */ +#include #include +#include #include #include +#include #include #include #include @@ -24,6 +27,518 @@ #include "internal.h" +enum { + SKCIPHER_WALK_PHYS = 1 << 0, + SKCIPHER_WALK_SLOW = 1 << 1, + SKCIPHER_WALK_COPY = 1 << 2, + SKCIPHER_WALK_DIFF = 1 << 3, + SKCIPHER_WALK_SLEEP = 1 << 4, +}; + +struct skcipher_walk_buffer { + struct list_head entry; + struct scatter_walk dst; + unsigned int len; + u8 *data; + u8 buffer[]; +}; + +static int skcipher_walk_next(struct skcipher_walk *walk); + +static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr) +{ + if (PageHighMem(scatterwalk_page(walk))) + kunmap_atomic(vaddr); +} + +static inline void *skcipher_map(struct scatter_walk *walk) +{ + struct page *page = scatterwalk_page(walk); + + return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) + + offset_in_page(walk->offset); +} + +static inline void skcipher_map_src(struct skcipher_walk *walk) +{ + walk->src.virt.addr = skcipher_map(&walk->in); +} + +static inline void skcipher_map_dst(struct skcipher_walk *walk) +{ + walk->dst.virt.addr = skcipher_map(&walk->out); +} + +static inline void skcipher_unmap_src(struct skcipher_walk *walk) +{ + skcipher_unmap(&walk->in, walk->src.virt.addr); +} + +static inline void skcipher_unmap_dst(struct skcipher_walk *walk) +{ + skcipher_unmap(&walk->out, walk->dst.virt.addr); +} + +static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk) +{ + return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC; +} + +/* 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 *skcipher_get_spot(u8 *start, unsigned int len) +{ + u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK); + + return max(start, end_page); +} + +static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize) +{ + u8 *addr; + + addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1); + addr = skcipher_get_spot(addr, bsize); + scatterwalk_copychunks(addr, &walk->out, bsize, + (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1); + return 0; +} + +int skcipher_walk_done(struct skcipher_walk *walk, int err) +{ + unsigned int nbytes = 0; + unsigned int n = 0; + + if (likely(err >= 0)) { + n = walk->nbytes - err; + nbytes = walk->total - n; + } + + if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | + SKCIPHER_WALK_SLOW | + SKCIPHER_WALK_COPY | + SKCIPHER_WALK_DIFF)))) { +unmap_src: + skcipher_unmap_src(walk); + } else if (walk->flags & SKCIPHER_WALK_DIFF) { + skcipher_unmap_dst(walk); + goto unmap_src; + } else if (walk->flags & SKCIPHER_WALK_COPY) { + skcipher_map_dst(walk); + memcpy(walk->dst.virt.addr, walk->page, n); + skcipher_unmap_dst(walk); + } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) { + if (!err) + n = skcipher_done_slow(walk, n); + else if (WARN_ON(err > 0)) { + err = -EINVAL; + nbytes = 0; + } + } + + if (err >= 0) + err = 0; + + walk->total = nbytes; + walk->nbytes = nbytes; + + scatterwalk_advance(&walk->in, n); + scatterwalk_advance(&walk->out, n); + scatterwalk_done(&walk->in, 0, nbytes); + scatterwalk_done(&walk->out, 1, nbytes); + + if (nbytes) { + crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ? + CRYPTO_TFM_REQ_MAY_SLEEP : 0); + return skcipher_walk_next(walk); + } + + /* Short-circuit for the common/fast path. */ + if (!(((unsigned long)walk->iv ^ (unsigned long)walk->oiv) | + ((unsigned long)walk->buffer ^ (unsigned long)walk->page) | + (unsigned long)walk->page)) + goto out; + + if (walk->flags & SKCIPHER_WALK_PHYS) + goto out; + + if (walk->iv != walk->oiv) + memcpy(walk->oiv, walk->iv, walk->ivsize); + if (walk->buffer != walk->page) + kfree(walk->buffer); + if (walk->page) + free_page((unsigned long)walk->page); + +out: + return err; +} +EXPORT_SYMBOL_GPL(skcipher_walk_done); + +void skcipher_walk_complete(struct skcipher_walk *walk, int err) +{ + struct skcipher_walk_buffer *p, *tmp; + + list_for_each_entry_safe(p, tmp, &walk->buffers, entry) { + u8 *data; + + if (err) + goto done; + + data = p->data; + if (!data) { + data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1); + data = skcipher_get_spot(data, walk->chunksize); + } + + scatterwalk_copychunks(data, &p->dst, p->len, 1); + + if (offset_in_page(p->data) + p->len + walk->chunksize > + PAGE_SIZE) + free_page((unsigned long)p->data); + +done: + list_del(&p->entry); + kfree(p); + } + + if (!err && walk->iv != walk->oiv) + memcpy(walk->oiv, walk->iv, walk->ivsize); + if (walk->buffer != walk->page) + kfree(walk->buffer); + if (walk->page) + free_page((unsigned long)walk->page); +} +EXPORT_SYMBOL_GPL(skcipher_walk_complete); + +static void skcipher_queue_write(struct skcipher_walk *walk, + struct skcipher_walk_buffer *p) +{ + p->dst = walk->out; + list_add_tail(&p->entry, &walk->buffers); +} + +static int skcipher_next_slow(struct skcipher_walk *walk) +{ + bool phys = walk->flags & SKCIPHER_WALK_PHYS; + unsigned alignmask = walk->alignmask; + unsigned bsize = walk->chunksize; + struct skcipher_walk_buffer *p; + unsigned a; + unsigned n; + u8 *buffer; + void *v; + + if (!phys) { + buffer = walk->buffer ?: walk->page; + if (buffer) + goto ok; + } + + /* Start with the minimum alignment of kmalloc. */ + a = crypto_tfm_ctx_alignment() - 1; + n = bsize; + + if (phys) { + /* Calculate the minimum alignment of p->buffer. */ + a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1; + n += sizeof(*p); + } + + /* Minimum size to align p->buffer by alignmask. */ + n += alignmask & ~a; + + /* Minimum size to ensure p->buffer does not straddle a page. */ + n += (bsize - 1) & ~(alignmask | a); + + v = kzalloc(n, skcipher_walk_gfp(walk)); + if (!v) + return skcipher_walk_done(walk, -ENOMEM); + + if (phys) { + p = v; + p->len = bsize; + skcipher_queue_write(walk, p); + buffer = p->buffer; + } else { + walk->buffer = v; + buffer = v; + } + +ok: + walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1); + walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize); + walk->src.virt.addr = walk->dst.virt.addr; + + scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); + + walk->nbytes = bsize; + walk->flags |= SKCIPHER_WALK_SLOW; + + return 0; +} + +static int skcipher_next_copy(struct skcipher_walk *walk) +{ + struct skcipher_walk_buffer *p; + u8 *tmp = walk->page; + + skcipher_map_src(walk); + memcpy(tmp, walk->src.virt.addr, walk->nbytes); + skcipher_unmap_src(walk); + + walk->src.virt.addr = tmp; + walk->dst.virt.addr = tmp; + + if (!(walk->flags & SKCIPHER_WALK_PHYS)) + return 0; + + p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk)); + if (!p) + return -ENOMEM; + + p->data = walk->page; + p->len = walk->nbytes; + skcipher_queue_write(walk, p); + + if (offset_in_page(walk->page) + walk->nbytes + walk->chunksize > + PAGE_SIZE) + walk->page = NULL; + else + walk->page += walk->nbytes; + + return 0; +} + +static int skcipher_next_fast(struct skcipher_walk *walk) +{ + unsigned long diff; + + walk->src.phys.page = scatterwalk_page(&walk->in); + walk->src.phys.offset = offset_in_page(walk->in.offset); + walk->dst.phys.page = scatterwalk_page(&walk->out); + walk->dst.phys.offset = offset_in_page(walk->out.offset); + + if (walk->flags & SKCIPHER_WALK_PHYS) + return 0; + + diff = walk->src.phys.offset - walk->dst.phys.offset; + diff |= walk->src.virt.page - walk->dst.virt.page; + + skcipher_map_src(walk); + walk->dst.virt.addr = walk->src.virt.addr; + + if (diff) { + walk->flags |= SKCIPHER_WALK_DIFF; + skcipher_map_dst(walk); + } + + return 0; +} + +int skcipher_walk_next(struct skcipher_walk *walk) +{ + unsigned int bsize; + unsigned int n; + int err; + + walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY | + SKCIPHER_WALK_DIFF); + + n = walk->total; + bsize = min(walk->chunksize, max(n, walk->blocksize)); + n = scatterwalk_clamp(&walk->in, n); + n = scatterwalk_clamp(&walk->out, n); + + if (unlikely(n < bsize)) { + if (unlikely(walk->total < walk->blocksize)) + return skcipher_walk_done(walk, -EINVAL); + +slow_path: + err = skcipher_next_slow(walk); + goto set_phys_lowmem; + } + + if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) { + if (!walk->page) { + gfp_t gfp = skcipher_walk_gfp(walk); + + walk->page = (void *)__get_free_page(gfp); + if (!walk->page) + goto slow_path; + } + + walk->nbytes = min_t(unsigned, n, + PAGE_SIZE - offset_in_page(walk->page)); + walk->flags |= SKCIPHER_WALK_COPY; + err = skcipher_next_copy(walk); + goto set_phys_lowmem; + } + + walk->nbytes = n; + + return skcipher_next_fast(walk); + +set_phys_lowmem: + if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) { + walk->src.phys.page = virt_to_page(walk->src.virt.addr); + walk->dst.phys.page = virt_to_page(walk->dst.virt.addr); + walk->src.phys.offset &= PAGE_SIZE - 1; + walk->dst.phys.offset &= PAGE_SIZE - 1; + } + return err; +} +EXPORT_SYMBOL_GPL(skcipher_walk_next); + +static int skcipher_copy_iv(struct skcipher_walk *walk) +{ + unsigned a = crypto_tfm_ctx_alignment() - 1; + unsigned alignmask = walk->alignmask; + unsigned ivsize = walk->ivsize; + unsigned bs = walk->chunksize; + unsigned aligned_bs; + unsigned size; + u8 *iv; + + aligned_bs = ALIGN(bs, alignmask); + + /* Minimum size to align buffer by alignmask. */ + size = alignmask & ~a; + + if (walk->flags & SKCIPHER_WALK_PHYS) + size += ivsize; + else { + size += aligned_bs + ivsize; + + /* Minimum size to ensure buffer does not straddle a page. */ + size += (bs - 1) & ~(alignmask | a); + } + + walk->buffer = kmalloc(size, skcipher_walk_gfp(walk)); + if (!walk->buffer) + return -ENOMEM; + + iv = PTR_ALIGN(walk->buffer, alignmask + 1); + iv = skcipher_get_spot(iv, bs) + aligned_bs; + + walk->iv = memcpy(iv, walk->iv, walk->ivsize); + return 0; +} + +static int skcipher_walk_first(struct skcipher_walk *walk) +{ + walk->nbytes = 0; + + if (WARN_ON_ONCE(in_irq())) + return -EDEADLK; + + if (unlikely(!walk->total)) + return 0; + + walk->buffer = NULL; + if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { + int err = skcipher_copy_iv(walk); + if (err) + return err; + } + + walk->page = NULL; + walk->nbytes = walk->total; + + return skcipher_walk_next(walk); +} + +static int skcipher_walk_skcipher(struct skcipher_walk *walk, + struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + + scatterwalk_start(&walk->in, req->src); + scatterwalk_start(&walk->out, req->dst); + + walk->total = req->cryptlen; + walk->iv = req->iv; + walk->oiv = req->iv; + + walk->flags &= ~SKCIPHER_WALK_SLEEP; + walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? + SKCIPHER_WALK_SLEEP : 0; + + walk->blocksize = crypto_skcipher_blocksize(tfm); + walk->chunksize = crypto_skcipher_chunksize(tfm); + walk->ivsize = crypto_skcipher_ivsize(tfm); + walk->alignmask = crypto_skcipher_alignmask(tfm); + + return skcipher_walk_first(walk); +} + +int skcipher_walk_virt(struct skcipher_walk *walk, + struct skcipher_request *req, bool atomic) +{ + int err; + + walk->flags &= ~SKCIPHER_WALK_PHYS; + + err = skcipher_walk_skcipher(walk, req); + + walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0; + + return err; +} +EXPORT_SYMBOL_GPL(skcipher_walk_virt); + +void skcipher_walk_atomise(struct skcipher_walk *walk) +{ + walk->flags &= ~SKCIPHER_WALK_SLEEP; +} +EXPORT_SYMBOL_GPL(skcipher_walk_atomise); + +int skcipher_walk_async(struct skcipher_walk *walk, + struct skcipher_request *req) +{ + walk->flags |= SKCIPHER_WALK_PHYS; + + INIT_LIST_HEAD(&walk->buffers); + + return skcipher_walk_skcipher(walk, req); +} +EXPORT_SYMBOL_GPL(skcipher_walk_async); + +int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req, + bool atomic) +{ + struct crypto_aead *tfm = crypto_aead_reqtfm(req); + int err; + + scatterwalk_start(&walk->in, req->src); + scatterwalk_start(&walk->out, req->dst); + + scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2); + scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2); + + walk->total = req->cryptlen; + walk->iv = req->iv; + walk->oiv = req->iv; + + if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) + walk->flags |= SKCIPHER_WALK_SLEEP; + else + walk->flags &= ~SKCIPHER_WALK_SLEEP; + + walk->blocksize = crypto_aead_blocksize(tfm); + walk->chunksize = crypto_aead_chunksize(tfm); + walk->ivsize = crypto_aead_ivsize(tfm); + walk->alignmask = crypto_aead_alignmask(tfm); + + err = skcipher_walk_first(walk); + + if (atomic) + walk->flags &= ~SKCIPHER_WALK_SLEEP; + + return err; +} +EXPORT_SYMBOL_GPL(skcipher_walk_aead); + static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) { if (alg->cra_type == &crypto_blkcipher_type) diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h index 7a7e815..d55041f 100644 --- a/include/crypto/internal/skcipher.h +++ b/include/crypto/internal/skcipher.h @@ -15,8 +15,10 @@ #include #include +#include #include +struct aead_request; struct rtattr; struct skcipher_instance { @@ -34,6 +36,40 @@ struct crypto_skcipher_spawn { struct crypto_spawn base; }; +struct skcipher_walk { + union { + struct { + struct page *page; + unsigned long offset; + } phys; + + struct { + u8 *page; + void *addr; + } virt; + } src, dst; + + struct scatter_walk in; + unsigned int nbytes; + + struct scatter_walk out; + unsigned int total; + + struct list_head buffers; + + u8 *page; + u8 *buffer; + u8 *oiv; + void *iv; + + unsigned int ivsize; + + int flags; + unsigned int blocksize; + unsigned int chunksize; + unsigned int alignmask; +}; + extern const struct crypto_type crypto_givcipher_type; static inline struct crypto_instance *skcipher_crypto_instance( @@ -104,6 +140,17 @@ static inline void crypto_skcipher_set_reqsize( int skcipher_register_instance(struct crypto_template *tmpl, struct skcipher_instance *inst); +int skcipher_walk_done(struct skcipher_walk *walk, int err); +int skcipher_walk_virt(struct skcipher_walk *walk, + struct skcipher_request *req, + bool atomic); +void skcipher_walk_atomise(struct skcipher_walk *walk); +int skcipher_walk_async(struct skcipher_walk *walk, + struct skcipher_request *req); +int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req, + bool atomic); +void skcipher_walk_complete(struct skcipher_walk *walk, int err); + static inline void ablkcipher_request_complete(struct ablkcipher_request *req, int err) {