diff options
Diffstat (limited to 'crypto/skcipher.c')
| -rw-r--r-- | crypto/skcipher.c | 893 |
1 files changed, 893 insertions, 0 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c new file mode 100644 index 000000000000..14a820cb06c7 --- /dev/null +++ b/crypto/skcipher.c @@ -0,0 +1,893 @@ +// 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/err.h> +#include <linux/kernel.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_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 gfp_t skcipher_walk_gfp(struct skcipher_walk *walk) +{ + return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC; +} + +static inline struct skcipher_alg *__crypto_skcipher_alg( + struct crypto_alg *alg) +{ + return container_of(alg, struct skcipher_alg, base); +} + +/** + * 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; /* num bytes processed this step */ + unsigned int total = 0; /* new total remaining */ + + if (!n) + goto finish; + + if (likely(res >= 0)) { + n -= res; /* subtract num bytes *not* processed */ + total = walk->total - n; + } + + if (likely(!(walk->flags & (SKCIPHER_WALK_SLOW | + SKCIPHER_WALK_COPY | + SKCIPHER_WALK_DIFF)))) { + scatterwalk_advance(&walk->in, n); + } else if (walk->flags & SKCIPHER_WALK_DIFF) { + scatterwalk_done_src(&walk->in, n); + } else if (walk->flags & SKCIPHER_WALK_COPY) { + 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. + */ + res = -EINVAL; + total = 0; + } else + memcpy_to_scatterwalk(&walk->out, walk->out.addr, n); + goto dst_done; + } + + scatterwalk_done_dst(&walk->out, n); +dst_done: + + if (res > 0) + res = 0; + + walk->total = total; + walk->nbytes = 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); + } + +finish: + /* Short-circuit for the common/fast path. */ + if (!((unsigned long)walk->buffer | (unsigned long)walk->page)) + 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 res; +} +EXPORT_SYMBOL_GPL(skcipher_walk_done); + +static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize) +{ + unsigned alignmask = walk->alignmask; + unsigned n; + void *buffer; + + 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; + } + + 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; + + return 0; +} + +static int skcipher_next_copy(struct skcipher_walk *walk) +{ + void *tmp = walk->page; + + 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; +} + +static int skcipher_next_fast(struct skcipher_walk *walk) +{ + unsigned long diff; + + 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)); + + scatterwalk_map(&walk->out); + walk->in.__addr = walk->out.__addr; + + if (diff) { + walk->flags |= SKCIPHER_WALK_DIFF; + scatterwalk_map(&walk->in); + } + + return 0; +} + +static int skcipher_walk_next(struct skcipher_walk *walk) +{ + unsigned int bsize; + unsigned int n; + + 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: + return skcipher_next_slow(walk, bsize); + } + walk->nbytes = n; + + 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->flags |= SKCIPHER_WALK_COPY; + return skcipher_next_copy(walk); + } + + return skcipher_next_fast(walk); +} + +static int skcipher_copy_iv(struct skcipher_walk *walk) +{ + unsigned alignmask = walk->alignmask; + unsigned ivsize = walk->ivsize; + unsigned aligned_stride = ALIGN(walk->stride, alignmask + 1); + unsigned size; + u8 *iv; + + /* 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) + aligned_stride; + + 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); +} + +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; + + 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; + + scatterwalk_start(&walk->in, req->src); + scatterwalk_start(&walk->out, req->dst); + + walk->blocksize = crypto_skcipher_blocksize(tfm); + walk->ivsize = crypto_skcipher_ivsize(tfm); + walk->alignmask = crypto_skcipher_alignmask(tfm); + + if (alg->co.base.cra_type != &crypto_skcipher_type) + walk->stride = alg->co.chunksize; + else + walk->stride = alg->walksize; + + return skcipher_walk_first(walk); +} +EXPORT_SYMBOL_GPL(skcipher_walk_virt); + +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); + + 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; + + 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); + + return skcipher_walk_first(walk); +} + +int skcipher_walk_aead_encrypt(struct skcipher_walk *__restrict walk, + struct aead_request *__restrict 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 *__restrict walk, + struct aead_request *__restrict 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 (cipher->co.base.cra_type != &crypto_skcipher_type) { + struct crypto_lskcipher **ctx = crypto_skcipher_ctx(tfm); + + crypto_lskcipher_clear_flags(*ctx, CRYPTO_TFM_REQ_MASK); + crypto_lskcipher_set_flags(*ctx, + crypto_skcipher_get_flags(tfm) & + CRYPTO_TFM_REQ_MASK); + err = crypto_lskcipher_setkey(*ctx, key, keylen); + goto out; + } + + 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); + +out: + 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 skcipher_alg *alg = crypto_skcipher_alg(tfm); + + if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) + return -ENOKEY; + if (alg->co.base.cra_type != &crypto_skcipher_type) + return crypto_lskcipher_encrypt_sg(req); + return alg->encrypt(req); +} +EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt); + +int crypto_skcipher_decrypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct skcipher_alg *alg = crypto_skcipher_alg(tfm); + + if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) + return -ENOKEY; + if (alg->co.base.cra_type != &crypto_skcipher_type) + return crypto_lskcipher_decrypt_sg(req); + return alg->decrypt(req); +} +EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt); + +static int crypto_lskcipher_export(struct skcipher_request *req, void *out) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + u8 *ivs = skcipher_request_ctx(req); + + ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(tfm) + 1); + + memcpy(out, ivs + crypto_skcipher_ivsize(tfm), + crypto_skcipher_statesize(tfm)); + + return 0; +} + +static int crypto_lskcipher_import(struct skcipher_request *req, const void *in) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + u8 *ivs = skcipher_request_ctx(req); + + ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(tfm) + 1); + + memcpy(ivs + crypto_skcipher_ivsize(tfm), in, + crypto_skcipher_statesize(tfm)); + + return 0; +} + +static int skcipher_noexport(struct skcipher_request *req, void *out) +{ + return 0; +} + +static int skcipher_noimport(struct skcipher_request *req, const void *in) +{ + return 0; +} + +int crypto_skcipher_export(struct skcipher_request *req, void *out) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct skcipher_alg *alg = crypto_skcipher_alg(tfm); + + if (alg->co.base.cra_type != &crypto_skcipher_type) + return crypto_lskcipher_export(req, out); + return alg->export(req, out); +} +EXPORT_SYMBOL_GPL(crypto_skcipher_export); + +int crypto_skcipher_import(struct skcipher_request *req, const void *in) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct skcipher_alg *alg = crypto_skcipher_alg(tfm); + + if (alg->co.base.cra_type != &crypto_skcipher_type) + return crypto_lskcipher_import(req, in); + return alg->import(req, in); +} +EXPORT_SYMBOL_GPL(crypto_skcipher_import); + +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 (tfm->__crt_alg->cra_type != &crypto_skcipher_type) { + unsigned am = crypto_skcipher_alignmask(skcipher); + unsigned reqsize; + + reqsize = am & ~(crypto_tfm_ctx_alignment() - 1); + reqsize += crypto_skcipher_ivsize(skcipher); + reqsize += crypto_skcipher_statesize(skcipher); + crypto_skcipher_set_reqsize(skcipher, reqsize); + + return crypto_init_lskcipher_ops_sg(tfm); + } + + crypto_skcipher_set_reqsize(skcipher, crypto_tfm_alg_reqsize(tfm)); + + if (alg->exit) + skcipher->base.exit = crypto_skcipher_exit_tfm; + + if (alg->init) + return alg->init(skcipher); + + return 0; +} + +static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) +{ + if (alg->cra_type != &crypto_skcipher_type) + return sizeof(struct crypto_lskcipher *); + + return crypto_alg_extsize(alg); +} + +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 = __crypto_skcipher_alg(alg); + + seq_printf(m, "type : skcipher\n"); + seq_printf(m, "async : %s\n", + 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); + seq_printf(m, "ivsize : %u\n", skcipher->ivsize); + seq_printf(m, "chunksize : %u\n", skcipher->chunksize); + seq_printf(m, "walksize : %u\n", skcipher->walksize); + seq_printf(m, "statesize : %u\n", skcipher->statesize); +} + +static int __maybe_unused crypto_skcipher_report( + struct sk_buff *skb, struct crypto_alg *alg) +{ + struct skcipher_alg *skcipher = __crypto_skcipher_alg(alg); + struct crypto_report_blkcipher rblkcipher; + + 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); +} + +static const struct crypto_type crypto_skcipher_type = { + .extsize = crypto_skcipher_extsize, + .init_tfm = crypto_skcipher_init_tfm, + .free = crypto_skcipher_free_instance, +#ifdef CONFIG_PROC_FS + .show = crypto_skcipher_show, +#endif +#if IS_ENABLED(CONFIG_CRYPTO_USER) + .report = crypto_skcipher_report, +#endif + .maskclear = ~CRYPTO_ALG_TYPE_MASK, + .maskset = CRYPTO_ALG_TYPE_SKCIPHER_MASK, + .type = CRYPTO_ALG_TYPE_SKCIPHER, + .tfmsize = offsetof(struct crypto_skcipher, base), + .algsize = offsetof(struct skcipher_alg, 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 | 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); + + /* + * 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); + +int skcipher_prepare_alg_common(struct skcipher_alg_common *alg) +{ + struct crypto_alg *base = &alg->base; + + if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || + alg->statesize > PAGE_SIZE / 2 || + (alg->ivsize + alg->statesize) > PAGE_SIZE / 2) + return -EINVAL; + + if (!alg->chunksize) + alg->chunksize = base->cra_blocksize; + + base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; + + return 0; +} + +static int skcipher_prepare_alg(struct skcipher_alg *alg) +{ + struct crypto_alg *base = &alg->base; + int err; + + err = skcipher_prepare_alg_common(&alg->co); + if (err) + return err; + + if (alg->walksize > PAGE_SIZE / 8) + return -EINVAL; + + if (!alg->walksize) + alg->walksize = alg->chunksize; + + if (!alg->statesize) { + alg->import = skcipher_noimport; + alg->export = skcipher_noexport; + } else if (!(alg->import && alg->export)) + return -EINVAL; + + base->cra_type = &crypto_skcipher_type; + 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"); |