diff options
Diffstat (limited to 'crypto/skcipher.c')
| -rw-r--r-- | crypto/skcipher.c | 984 |
1 files changed, 984 insertions, 0 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c new file mode 100644 index 000000000..418211180 --- /dev/null +++ b/crypto/skcipher.c @@ -0,0 +1,984 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Symmetric key cipher operations. + * + * Generic encrypt/decrypt wrapper for ciphers, handles operations across + * multiple page boundaries by using temporary blocks. In user context, + * the kernel is given a chance to schedule us once per page. + * + * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> + */ + +#include <crypto/internal/aead.h> +#include <crypto/internal/cipher.h> +#include <crypto/internal/skcipher.h> +#include <crypto/scatterwalk.h> +#include <linux/bug.h> +#include <linux/cryptouser.h> +#include <linux/compiler.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/rtnetlink.h> +#include <linux/seq_file.h> +#include <net/netlink.h> + +#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 n = walk->nbytes; + unsigned int nbytes = 0; + + if (!n) + goto finish; + + if (likely(err >= 0)) { + n -= 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 > 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; + } else + n = skcipher_done_slow(walk, n); + } + + if (err > 0) + err = 0; + + walk->total = nbytes; + walk->nbytes = 0; + + 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); + } + +finish: + /* Short-circuit for the common/fast path. */ + 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) + 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->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); + + 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->stride > + 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; +} + +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)); + 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, bsize); + 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; +} + +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 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); + } + + 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) +{ + if (WARN_ON_ONCE(in_hardirq())) + return -EDEADLK; + + walk->buffer = NULL; + if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { + int err = skcipher_copy_iv(walk); + if (err) + return err; + } + + walk->page = NULL; + + 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); + + walk->total = req->cryptlen; + walk->nbytes = 0; + walk->iv = req->iv; + walk->oiv = req->iv; + + if (unlikely(!walk->total)) + return 0; + + 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->stride = crypto_skcipher_walksize(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; + + 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) +{ + struct crypto_aead *tfm = crypto_aead_reqtfm(req); + int err; + + walk->nbytes = 0; + walk->iv = req->iv; + walk->oiv = req->iv; + + 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; + + 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; +} + +int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, + struct aead_request *req, bool atomic) +{ + walk->total = req->cryptlen; + + return skcipher_walk_aead_common(walk, req, atomic); +} +EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt); + +int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, + struct aead_request *req, bool atomic) +{ + struct crypto_aead *tfm = crypto_aead_reqtfm(req); + + walk->total = req->cryptlen - crypto_aead_authsize(tfm); + + return skcipher_walk_aead_common(walk, req, atomic); +} +EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt); + +static void skcipher_set_needkey(struct crypto_skcipher *tfm) +{ + if (crypto_skcipher_max_keysize(tfm) != 0) + crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY); +} + +static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, + const u8 *key, unsigned int keylen) +{ + unsigned long alignmask = crypto_skcipher_alignmask(tfm); + struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); + u8 *buffer, *alignbuffer; + unsigned long absize; + int ret; + + absize = keylen + alignmask; + buffer = kmalloc(absize, GFP_ATOMIC); + if (!buffer) + return -ENOMEM; + + alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); + memcpy(alignbuffer, key, keylen); + ret = cipher->setkey(tfm, alignbuffer, keylen); + kfree_sensitive(buffer); + return ret; +} + +int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen) +{ + struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); + unsigned long alignmask = crypto_skcipher_alignmask(tfm); + int err; + + if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) + return -EINVAL; + + if ((unsigned long)key & alignmask) + err = skcipher_setkey_unaligned(tfm, key, keylen); + else + err = cipher->setkey(tfm, key, keylen); + + if (unlikely(err)) { + skcipher_set_needkey(tfm); + return err; + } + + crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); + return 0; +} +EXPORT_SYMBOL_GPL(crypto_skcipher_setkey); + +int crypto_skcipher_encrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_alg *alg = tfm->base.__crt_alg; + unsigned int cryptlen = req->cryptlen; + int ret; + + crypto_stats_get(alg); + if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) + ret = -ENOKEY; + else + ret = crypto_skcipher_alg(tfm)->encrypt(req); + crypto_stats_skcipher_encrypt(cryptlen, ret, alg); + return ret; +} +EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt); + +int crypto_skcipher_decrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_alg *alg = tfm->base.__crt_alg; + unsigned int cryptlen = req->cryptlen; + int ret; + + crypto_stats_get(alg); + if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) + ret = -ENOKEY; + else + ret = crypto_skcipher_alg(tfm)->decrypt(req); + crypto_stats_skcipher_decrypt(cryptlen, ret, alg); + return ret; +} +EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt); + +static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) +{ + struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); + struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); + + alg->exit(skcipher); +} + +static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); + struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); + + skcipher_set_needkey(skcipher); + + if (alg->exit) + skcipher->base.exit = crypto_skcipher_exit_tfm; + + if (alg->init) + return alg->init(skcipher); + + return 0; +} + +static void crypto_skcipher_free_instance(struct crypto_instance *inst) +{ + struct skcipher_instance *skcipher = + container_of(inst, struct skcipher_instance, s.base); + + skcipher->free(skcipher); +} + +static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) + __maybe_unused; +static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) +{ + struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, + base); + + seq_printf(m, "type : skcipher\n"); + seq_printf(m, "async : %s\n", + alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); + 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); + seq_printf(m, "ivsize : %u\n", skcipher->ivsize); + seq_printf(m, "chunksize : %u\n", skcipher->chunksize); + seq_printf(m, "walksize : %u\n", skcipher->walksize); +} + +#ifdef CONFIG_NET +static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) +{ + struct crypto_report_blkcipher rblkcipher; + struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, + base); + + memset(&rblkcipher, 0, sizeof(rblkcipher)); + + strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); + strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); + + rblkcipher.blocksize = alg->cra_blocksize; + rblkcipher.min_keysize = skcipher->min_keysize; + rblkcipher.max_keysize = skcipher->max_keysize; + rblkcipher.ivsize = skcipher->ivsize; + + return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, + sizeof(rblkcipher), &rblkcipher); +} +#else +static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) +{ + return -ENOSYS; +} +#endif + +static const struct crypto_type crypto_skcipher_type = { + .extsize = crypto_alg_extsize, + .init_tfm = crypto_skcipher_init_tfm, + .free = crypto_skcipher_free_instance, +#ifdef CONFIG_PROC_FS + .show = crypto_skcipher_show, +#endif + .report = crypto_skcipher_report, + .maskclear = ~CRYPTO_ALG_TYPE_MASK, + .maskset = CRYPTO_ALG_TYPE_MASK, + .type = CRYPTO_ALG_TYPE_SKCIPHER, + .tfmsize = offsetof(struct crypto_skcipher, base), +}; + +int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, + struct crypto_instance *inst, + const char *name, u32 type, u32 mask) +{ + spawn->base.frontend = &crypto_skcipher_type; + return crypto_grab_spawn(&spawn->base, inst, name, type, mask); +} +EXPORT_SYMBOL_GPL(crypto_grab_skcipher); + +struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, + u32 type, u32 mask) +{ + return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask); +} +EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); + +struct crypto_sync_skcipher *crypto_alloc_sync_skcipher( + const char *alg_name, u32 type, u32 mask) +{ + struct crypto_skcipher *tfm; + + /* Only sync algorithms allowed. */ + mask |= CRYPTO_ALG_ASYNC; + + tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask); + + /* + * Make sure we do not allocate something that might get used with + * an on-stack request: check the request size. + */ + if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) > + MAX_SYNC_SKCIPHER_REQSIZE)) { + crypto_free_skcipher(tfm); + return ERR_PTR(-EINVAL); + } + + return (struct crypto_sync_skcipher *)tfm; +} +EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher); + +int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask) +{ + return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask); +} +EXPORT_SYMBOL_GPL(crypto_has_skcipher); + +static int skcipher_prepare_alg(struct skcipher_alg *alg) +{ + struct crypto_alg *base = &alg->base; + + if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || + alg->walksize > PAGE_SIZE / 8) + return -EINVAL; + + if (!alg->chunksize) + alg->chunksize = base->cra_blocksize; + if (!alg->walksize) + alg->walksize = alg->chunksize; + + base->cra_type = &crypto_skcipher_type; + base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; + base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; + + return 0; +} + +int crypto_register_skcipher(struct skcipher_alg *alg) +{ + struct crypto_alg *base = &alg->base; + int err; + + err = skcipher_prepare_alg(alg); + if (err) + return err; + + return crypto_register_alg(base); +} +EXPORT_SYMBOL_GPL(crypto_register_skcipher); + +void crypto_unregister_skcipher(struct skcipher_alg *alg) +{ + crypto_unregister_alg(&alg->base); +} +EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); + +int crypto_register_skciphers(struct skcipher_alg *algs, int count) +{ + int i, ret; + + for (i = 0; i < count; i++) { + ret = crypto_register_skcipher(&algs[i]); + if (ret) + goto err; + } + + return 0; + +err: + for (--i; i >= 0; --i) + crypto_unregister_skcipher(&algs[i]); + + return ret; +} +EXPORT_SYMBOL_GPL(crypto_register_skciphers); + +void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) +{ + int i; + + for (i = count - 1; i >= 0; --i) + crypto_unregister_skcipher(&algs[i]); +} +EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); + +int skcipher_register_instance(struct crypto_template *tmpl, + struct skcipher_instance *inst) +{ + int err; + + if (WARN_ON(!inst->free)) + return -EINVAL; + + err = skcipher_prepare_alg(&inst->alg); + if (err) + return err; + + return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); +} +EXPORT_SYMBOL_GPL(skcipher_register_instance); + +static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen) +{ + struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); + + crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK); + crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) & + CRYPTO_TFM_REQ_MASK); + return crypto_cipher_setkey(cipher, key, keylen); +} + +static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm) +{ + struct skcipher_instance *inst = skcipher_alg_instance(tfm); + struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst); + struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); + struct crypto_cipher *cipher; + + cipher = crypto_spawn_cipher(spawn); + if (IS_ERR(cipher)) + return PTR_ERR(cipher); + + ctx->cipher = cipher; + return 0; +} + +static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm) +{ + struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); + + crypto_free_cipher(ctx->cipher); +} + +static void skcipher_free_instance_simple(struct skcipher_instance *inst) +{ + crypto_drop_cipher(skcipher_instance_ctx(inst)); + kfree(inst); +} + +/** + * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode + * + * Allocate an skcipher_instance for a simple block cipher mode of operation, + * e.g. cbc or ecb. The instance context will have just a single crypto_spawn, + * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize, + * alignmask, and priority are set from the underlying cipher but can be + * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and + * default ->setkey(), ->init(), and ->exit() methods are installed. + * + * @tmpl: the template being instantiated + * @tb: the template parameters + * + * Return: a pointer to the new instance, or an ERR_PTR(). The caller still + * needs to register the instance. + */ +struct skcipher_instance *skcipher_alloc_instance_simple( + struct crypto_template *tmpl, struct rtattr **tb) +{ + u32 mask; + struct skcipher_instance *inst; + struct crypto_cipher_spawn *spawn; + struct crypto_alg *cipher_alg; + int err; + + err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask); + if (err) + return ERR_PTR(err); + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return ERR_PTR(-ENOMEM); + spawn = skcipher_instance_ctx(inst); + + err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst), + crypto_attr_alg_name(tb[1]), 0, mask); + if (err) + goto err_free_inst; + cipher_alg = crypto_spawn_cipher_alg(spawn); + + err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name, + cipher_alg); + if (err) + goto err_free_inst; + + inst->free = skcipher_free_instance_simple; + + /* Default algorithm properties, can be overridden */ + inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize; + inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask; + inst->alg.base.cra_priority = cipher_alg->cra_priority; + inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize; + inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize; + inst->alg.ivsize = cipher_alg->cra_blocksize; + + /* Use skcipher_ctx_simple by default, can be overridden */ + inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple); + inst->alg.setkey = skcipher_setkey_simple; + inst->alg.init = skcipher_init_tfm_simple; + inst->alg.exit = skcipher_exit_tfm_simple; + + return inst; + +err_free_inst: + skcipher_free_instance_simple(inst); + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Symmetric key cipher type"); +MODULE_IMPORT_NS(CRYPTO_INTERNAL); |