diff options
Diffstat (limited to 'crypto/skcipher.c')
-rw-r--r-- | crypto/skcipher.c | 444 |
1 files changed, 123 insertions, 321 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c index f74e4d0d87a2..132075a905d9 100644 --- a/crypto/skcipher.c +++ b/crypto/skcipher.c @@ -17,143 +17,109 @@ #include <linux/cryptouser.h> #include <linux/err.h> #include <linux/kernel.h> -#include <linux/list.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/seq_file.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/string_choices.h> #include <net/netlink.h> #include "skcipher.h" #define CRYPTO_ALG_TYPE_SKCIPHER_MASK 0x0000000e 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[]; + SKCIPHER_WALK_SLOW = 1 << 0, + SKCIPHER_WALK_COPY = 1 << 1, + SKCIPHER_WALK_DIFF = 1 << 2, + SKCIPHER_WALK_SLEEP = 1 << 3, }; static const struct crypto_type crypto_skcipher_type; static int skcipher_walk_next(struct skcipher_walk *walk); -static inline void skcipher_map_src(struct skcipher_walk *walk) -{ - walk->src.virt.addr = scatterwalk_map(&walk->in); -} - -static inline void skcipher_map_dst(struct skcipher_walk *walk) -{ - walk->dst.virt.addr = scatterwalk_map(&walk->out); -} - -static inline void skcipher_unmap_src(struct skcipher_walk *walk) -{ - scatterwalk_unmap(walk->src.virt.addr); -} - -static inline void skcipher_unmap_dst(struct skcipher_walk *walk) -{ - scatterwalk_unmap(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 inline struct skcipher_alg *__crypto_skcipher_alg( struct crypto_alg *alg) { return container_of(alg, struct skcipher_alg, base); } -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) +/** + * skcipher_walk_done() - finish one step of a skcipher_walk + * @walk: the skcipher_walk + * @res: number of bytes *not* processed (>= 0) from walk->nbytes, + * or a -errno value to terminate the walk due to an error + * + * This function cleans up after one step of walking through the source and + * destination scatterlists, and advances to the next step if applicable. + * walk->nbytes is set to the number of bytes available in the next step, + * walk->total is set to the new total number of bytes remaining, and + * walk->{src,dst}.virt.addr is set to the next pair of data pointers. If there + * is no more data, or if an error occurred (i.e. -errno return), then + * walk->nbytes and walk->total are set to 0 and all resources owned by the + * skcipher_walk are freed. + * + * Return: 0 or a -errno value. If @res was a -errno value then it will be + * returned, but other errors may occur too. + */ +int skcipher_walk_done(struct skcipher_walk *walk, int res) { - unsigned int n = walk->nbytes; - unsigned int nbytes = 0; + unsigned int n = walk->nbytes; /* num bytes processed this step */ + unsigned int total = 0; /* new total remaining */ if (!n) goto finish; - if (likely(err >= 0)) { - n -= err; - nbytes = walk->total - n; + if (likely(res >= 0)) { + n -= res; /* subtract num bytes *not* processed */ + total = walk->total - n; } - if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | - SKCIPHER_WALK_SLOW | + if (likely(!(walk->flags & (SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY | SKCIPHER_WALK_DIFF)))) { -unmap_src: - skcipher_unmap_src(walk); + scatterwalk_advance(&walk->in, n); } else if (walk->flags & SKCIPHER_WALK_DIFF) { - skcipher_unmap_dst(walk); - goto unmap_src; + scatterwalk_done_src(&walk->in, n); } 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 > 0) { + scatterwalk_advance(&walk->in, n); + scatterwalk_map(&walk->out); + memcpy(walk->out.addr, walk->page, n); + } else { /* SKCIPHER_WALK_SLOW */ + if (res > 0) { /* * Didn't process all bytes. Either the algorithm is * broken, or this was the last step and it turned out * the message wasn't evenly divisible into blocks but * the algorithm requires it. */ - err = -EINVAL; - nbytes = 0; + res = -EINVAL; + total = 0; } else - n = skcipher_done_slow(walk, n); + memcpy_to_scatterwalk(&walk->out, walk->out.addr, n); + goto dst_done; } - if (err > 0) - err = 0; + scatterwalk_done_dst(&walk->out, n); +dst_done: - walk->total = nbytes; - walk->nbytes = 0; + if (res > 0) + res = 0; - scatterwalk_advance(&walk->in, n); - scatterwalk_advance(&walk->out, n); - scatterwalk_done(&walk->in, 0, nbytes); - scatterwalk_done(&walk->out, 1, nbytes); + walk->total = total; + walk->nbytes = 0; - if (nbytes) { - crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ? - CRYPTO_TFM_REQ_MAY_SLEEP : 0); + if (total) { + if (walk->flags & SKCIPHER_WALK_SLEEP) + cond_resched(); + walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY | + SKCIPHER_WALK_DIFF); return skcipher_walk_next(walk); } @@ -162,9 +128,6 @@ finish: if (!((unsigned long)walk->buffer | (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) @@ -173,107 +136,33 @@ finish: free_page((unsigned long)walk->page); out: - return err; + return res; } 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->stride); - } - - scatterwalk_copychunks(data, &p->dst, p->len, 1); - - if (offset_in_page(p->data) + p->len + walk->stride > - 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, unsigned int bsize) { - bool phys = walk->flags & SKCIPHER_WALK_PHYS; unsigned alignmask = walk->alignmask; - struct skcipher_walk_buffer *p; - unsigned a; unsigned n; - u8 *buffer; - void *v; - - if (!phys) { - if (!walk->buffer) - walk->buffer = walk->page; - buffer = walk->buffer; - 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); + void *buffer; - if (phys) { - p = v; - p->len = bsize; - skcipher_queue_write(walk, p); - buffer = p->buffer; - } else { - walk->buffer = v; - buffer = v; + if (!walk->buffer) + walk->buffer = walk->page; + buffer = walk->buffer; + if (!buffer) { + /* Min size for a buffer of bsize bytes aligned to alignmask */ + n = bsize + (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); + + buffer = kzalloc(n, skcipher_walk_gfp(walk)); + if (!buffer) + return skcipher_walk_done(walk, -ENOMEM); + walk->buffer = buffer; } -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); + buffer = PTR_ALIGN(buffer, alignmask + 1); + memcpy_from_scatterwalk(buffer, &walk->in, bsize); + walk->out.__addr = buffer; + walk->in.__addr = walk->out.addr; walk->nbytes = bsize; walk->flags |= SKCIPHER_WALK_SLOW; @@ -283,33 +172,18 @@ ok: 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; + void *tmp = walk->page; - p->data = walk->page; - p->len = walk->nbytes; - skcipher_queue_write(walk, p); - - if (offset_in_page(walk->page) + walk->nbytes + walk->stride > - PAGE_SIZE) - walk->page = NULL; - else - walk->page += walk->nbytes; + scatterwalk_map(&walk->in); + memcpy(tmp, walk->in.addr, walk->nbytes); + scatterwalk_unmap(&walk->in); + /* + * walk->in is advanced later when the number of bytes actually + * processed (which might be less than walk->nbytes) is known. + */ + walk->in.__addr = tmp; + walk->out.__addr = tmp; return 0; } @@ -317,23 +191,17 @@ 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; + diff = offset_in_page(walk->in.offset) - + offset_in_page(walk->out.offset); + diff |= (u8 *)(sg_page(walk->in.sg) + (walk->in.offset >> PAGE_SHIFT)) - + (u8 *)(sg_page(walk->out.sg) + (walk->out.offset >> PAGE_SHIFT)); - skcipher_map_src(walk); - walk->dst.virt.addr = walk->src.virt.addr; + scatterwalk_map(&walk->out); + walk->in.__addr = walk->out.__addr; if (diff) { walk->flags |= SKCIPHER_WALK_DIFF; - skcipher_map_dst(walk); + scatterwalk_map(&walk->in); } return 0; @@ -343,10 +211,6 @@ static 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->stride, max(n, walk->blocksize)); @@ -358,9 +222,9 @@ static int skcipher_walk_next(struct skcipher_walk *walk) return skcipher_walk_done(walk, -EINVAL); slow_path: - err = skcipher_next_slow(walk, bsize); - goto set_phys_lowmem; + return skcipher_next_slow(walk, bsize); } + walk->nbytes = n; if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) { if (!walk->page) { @@ -370,58 +234,30 @@ slow_path: 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; + return skcipher_next_copy(walk); } - 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; } 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->stride; - unsigned aligned_bs; + unsigned aligned_stride = ALIGN(walk->stride, alignmask + 1); unsigned size; u8 *iv; - aligned_bs = ALIGN(bs, alignmask + 1); - - /* 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); - } + /* Min size for a buffer of stride + ivsize, aligned to alignmask */ + size = aligned_stride + ivsize + + (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); 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; + iv = PTR_ALIGN(walk->buffer, alignmask + 1) + aligned_stride; walk->iv = memcpy(iv, walk->iv, walk->ivsize); return 0; @@ -444,16 +280,24 @@ static int skcipher_walk_first(struct skcipher_walk *walk) return skcipher_walk_next(walk); } -static int skcipher_walk_skcipher(struct skcipher_walk *walk, - struct skcipher_request *req) +int skcipher_walk_virt(struct skcipher_walk *__restrict walk, + struct skcipher_request *__restrict req, bool atomic) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); - struct skcipher_alg *alg = crypto_skcipher_alg(tfm); + struct skcipher_alg *alg; + + might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + + alg = crypto_skcipher_alg(tfm); walk->total = req->cryptlen; walk->nbytes = 0; walk->iv = req->iv; walk->oiv = req->iv; + if ((req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) && !atomic) + walk->flags = SKCIPHER_WALK_SLEEP; + else + walk->flags = 0; if (unlikely(!walk->total)) return 0; @@ -461,10 +305,6 @@ static int skcipher_walk_skcipher(struct skcipher_walk *walk, scatterwalk_start(&walk->in, req->src); scatterwalk_start(&walk->out, req->dst); - 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->ivsize = crypto_skcipher_ivsize(tfm); walk->alignmask = crypto_skcipher_alignmask(tfm); @@ -476,79 +316,39 @@ static int skcipher_walk_skcipher(struct skcipher_walk *walk, return skcipher_walk_first(walk); } - -int skcipher_walk_virt(struct skcipher_walk *walk, - struct skcipher_request *req, bool atomic) -{ - int err; - - might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); - - 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); -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); - -static int skcipher_walk_aead_common(struct skcipher_walk *walk, - struct aead_request *req, bool atomic) +static int skcipher_walk_aead_common(struct skcipher_walk *__restrict walk, + struct aead_request *__restrict req, + bool atomic) { struct crypto_aead *tfm = crypto_aead_reqtfm(req); - int err; walk->nbytes = 0; walk->iv = req->iv; walk->oiv = req->iv; + if ((req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) && !atomic) + walk->flags = SKCIPHER_WALK_SLEEP; + else + walk->flags = 0; if (unlikely(!walk->total)) return 0; - walk->flags &= ~SKCIPHER_WALK_PHYS; - - 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); - - scatterwalk_done(&walk->in, 0, walk->total); - scatterwalk_done(&walk->out, 0, walk->total); - - if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) - walk->flags |= SKCIPHER_WALK_SLEEP; - else - walk->flags &= ~SKCIPHER_WALK_SLEEP; + scatterwalk_start_at_pos(&walk->in, req->src, req->assoclen); + scatterwalk_start_at_pos(&walk->out, req->dst, req->assoclen); walk->blocksize = crypto_aead_blocksize(tfm); walk->stride = 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; + return skcipher_walk_first(walk); } -int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, - struct aead_request *req, bool atomic) +int skcipher_walk_aead_encrypt(struct skcipher_walk *__restrict walk, + struct aead_request *__restrict req, + bool atomic) { walk->total = req->cryptlen; @@ -556,8 +356,9 @@ int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, } EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt); -int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, - struct aead_request *req, bool atomic) +int skcipher_walk_aead_decrypt(struct skcipher_walk *__restrict walk, + struct aead_request *__restrict req, + bool atomic) { struct crypto_aead *tfm = crypto_aead_reqtfm(req); @@ -775,7 +576,7 @@ static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) seq_printf(m, "type : skcipher\n"); seq_printf(m, "async : %s\n", - alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); + str_yes_no(alg->cra_flags & CRYPTO_ALG_ASYNC)); seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); @@ -844,6 +645,7 @@ struct crypto_sync_skcipher *crypto_alloc_sync_skcipher( /* Only sync algorithms allowed. */ mask |= CRYPTO_ALG_ASYNC | CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE; + type &= ~(CRYPTO_ALG_ASYNC | CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE); tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask); |