diff options
Diffstat (limited to 'crypto/ahash.c')
| -rw-r--r-- | crypto/ahash.c | 615 |
1 files changed, 615 insertions, 0 deletions
diff --git a/crypto/ahash.c b/crypto/ahash.c new file mode 100644 index 000000000..8acb88603 --- /dev/null +++ b/crypto/ahash.c @@ -0,0 +1,615 @@ +/* + * Asynchronous Cryptographic Hash operations. + * + * This is the asynchronous version of hash.c with notification of + * completion via a callback. + * + * Copyright (c) 2008 Loc Ho <lho@amcc.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ + +#include <crypto/internal/hash.h> +#include <crypto/scatterwalk.h> +#include <linux/bug.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/seq_file.h> +#include <linux/cryptouser.h> +#include <net/netlink.h> + +#include "internal.h" + +struct ahash_request_priv { + crypto_completion_t complete; + void *data; + u8 *result; + void *ubuf[] CRYPTO_MINALIGN_ATTR; +}; + +static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash) +{ + return container_of(crypto_hash_alg_common(hash), struct ahash_alg, + halg); +} + +static int hash_walk_next(struct crypto_hash_walk *walk) +{ + unsigned int alignmask = walk->alignmask; + unsigned int offset = walk->offset; + unsigned int nbytes = min(walk->entrylen, + ((unsigned int)(PAGE_SIZE)) - offset); + + if (walk->flags & CRYPTO_ALG_ASYNC) + walk->data = kmap(walk->pg); + else + walk->data = kmap_atomic(walk->pg); + walk->data += offset; + + if (offset & alignmask) { + unsigned int unaligned = alignmask + 1 - (offset & alignmask); + + if (nbytes > unaligned) + nbytes = unaligned; + } + + walk->entrylen -= nbytes; + return nbytes; +} + +static int hash_walk_new_entry(struct crypto_hash_walk *walk) +{ + struct scatterlist *sg; + + sg = walk->sg; + walk->pg = sg_page(sg); + walk->offset = sg->offset; + walk->entrylen = sg->length; + + if (walk->entrylen > walk->total) + walk->entrylen = walk->total; + walk->total -= walk->entrylen; + + return hash_walk_next(walk); +} + +int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err) +{ + unsigned int alignmask = walk->alignmask; + unsigned int nbytes = walk->entrylen; + + walk->data -= walk->offset; + + if (nbytes && walk->offset & alignmask && !err) { + walk->offset = ALIGN(walk->offset, alignmask + 1); + walk->data += walk->offset; + + nbytes = min(nbytes, + ((unsigned int)(PAGE_SIZE)) - walk->offset); + walk->entrylen -= nbytes; + + return nbytes; + } + + if (walk->flags & CRYPTO_ALG_ASYNC) + kunmap(walk->pg); + else { + kunmap_atomic(walk->data); + /* + * The may sleep test only makes sense for sync users. + * Async users don't need to sleep here anyway. + */ + crypto_yield(walk->flags); + } + + if (err) + return err; + + if (nbytes) { + walk->offset = 0; + walk->pg++; + return hash_walk_next(walk); + } + + if (!walk->total) + return 0; + + walk->sg = sg_next(walk->sg); + + return hash_walk_new_entry(walk); +} +EXPORT_SYMBOL_GPL(crypto_hash_walk_done); + +int crypto_hash_walk_first(struct ahash_request *req, + struct crypto_hash_walk *walk) +{ + walk->total = req->nbytes; + + if (!walk->total) { + walk->entrylen = 0; + return 0; + } + + walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); + walk->sg = req->src; + walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; + + return hash_walk_new_entry(walk); +} +EXPORT_SYMBOL_GPL(crypto_hash_walk_first); + +int crypto_ahash_walk_first(struct ahash_request *req, + struct crypto_hash_walk *walk) +{ + walk->total = req->nbytes; + + if (!walk->total) { + walk->entrylen = 0; + return 0; + } + + walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req)); + walk->sg = req->src; + walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK; + walk->flags |= CRYPTO_ALG_ASYNC; + + BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC); + + return hash_walk_new_entry(walk); +} +EXPORT_SYMBOL_GPL(crypto_ahash_walk_first); + +int crypto_hash_walk_first_compat(struct hash_desc *hdesc, + struct crypto_hash_walk *walk, + struct scatterlist *sg, unsigned int len) +{ + walk->total = len; + + if (!walk->total) { + walk->entrylen = 0; + return 0; + } + + walk->alignmask = crypto_hash_alignmask(hdesc->tfm); + walk->sg = sg; + walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK; + + return hash_walk_new_entry(walk); +} + +static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key, + unsigned int keylen) +{ + unsigned long alignmask = crypto_ahash_alignmask(tfm); + int ret; + u8 *buffer, *alignbuffer; + unsigned long absize; + + absize = keylen + alignmask; + buffer = kmalloc(absize, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); + memcpy(alignbuffer, key, keylen); + ret = tfm->setkey(tfm, alignbuffer, keylen); + kzfree(buffer); + return ret; +} + +int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, + unsigned int keylen) +{ + unsigned long alignmask = crypto_ahash_alignmask(tfm); + + if ((unsigned long)key & alignmask) + return ahash_setkey_unaligned(tfm, key, keylen); + + return tfm->setkey(tfm, key, keylen); +} +EXPORT_SYMBOL_GPL(crypto_ahash_setkey); + +static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key, + unsigned int keylen) +{ + return -ENOSYS; +} + +static inline unsigned int ahash_align_buffer_size(unsigned len, + unsigned long mask) +{ + return len + (mask & ~(crypto_tfm_ctx_alignment() - 1)); +} + +static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt) +{ + struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); + unsigned long alignmask = crypto_ahash_alignmask(tfm); + unsigned int ds = crypto_ahash_digestsize(tfm); + struct ahash_request_priv *priv; + + priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask), + (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? + GFP_KERNEL : GFP_ATOMIC); + if (!priv) + return -ENOMEM; + + /* + * WARNING: Voodoo programming below! + * + * The code below is obscure and hard to understand, thus explanation + * is necessary. See include/crypto/hash.h and include/linux/crypto.h + * to understand the layout of structures used here! + * + * The code here will replace portions of the ORIGINAL request with + * pointers to new code and buffers so the hashing operation can store + * the result in aligned buffer. We will call the modified request + * an ADJUSTED request. + * + * The newly mangled request will look as such: + * + * req { + * .result = ADJUSTED[new aligned buffer] + * .base.complete = ADJUSTED[pointer to completion function] + * .base.data = ADJUSTED[*req (pointer to self)] + * .priv = ADJUSTED[new priv] { + * .result = ORIGINAL(result) + * .complete = ORIGINAL(base.complete) + * .data = ORIGINAL(base.data) + * } + */ + + priv->result = req->result; + priv->complete = req->base.complete; + priv->data = req->base.data; + /* + * WARNING: We do not backup req->priv here! The req->priv + * is for internal use of the Crypto API and the + * user must _NOT_ _EVER_ depend on it's content! + */ + + req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1); + req->base.complete = cplt; + req->base.data = req; + req->priv = priv; + + return 0; +} + +static void ahash_restore_req(struct ahash_request *req) +{ + struct ahash_request_priv *priv = req->priv; + + /* Restore the original crypto request. */ + req->result = priv->result; + req->base.complete = priv->complete; + req->base.data = priv->data; + req->priv = NULL; + + /* Free the req->priv.priv from the ADJUSTED request. */ + kzfree(priv); +} + +static void ahash_op_unaligned_finish(struct ahash_request *req, int err) +{ + struct ahash_request_priv *priv = req->priv; + + if (err == -EINPROGRESS) + return; + + if (!err) + memcpy(priv->result, req->result, + crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); + + ahash_restore_req(req); +} + +static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) +{ + struct ahash_request *areq = req->data; + + /* + * Restore the original request, see ahash_op_unaligned() for what + * goes where. + * + * The "struct ahash_request *req" here is in fact the "req.base" + * from the ADJUSTED request from ahash_op_unaligned(), thus as it + * is a pointer to self, it is also the ADJUSTED "req" . + */ + + /* First copy req->result into req->priv.result */ + ahash_op_unaligned_finish(areq, err); + + /* Complete the ORIGINAL request. */ + areq->base.complete(&areq->base, err); +} + +static int ahash_op_unaligned(struct ahash_request *req, + int (*op)(struct ahash_request *)) +{ + int err; + + err = ahash_save_req(req, ahash_op_unaligned_done); + if (err) + return err; + + err = op(req); + ahash_op_unaligned_finish(req, err); + + return err; +} + +static int crypto_ahash_op(struct ahash_request *req, + int (*op)(struct ahash_request *)) +{ + struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); + unsigned long alignmask = crypto_ahash_alignmask(tfm); + + if ((unsigned long)req->result & alignmask) + return ahash_op_unaligned(req, op); + + return op(req); +} + +int crypto_ahash_final(struct ahash_request *req) +{ + return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); +} +EXPORT_SYMBOL_GPL(crypto_ahash_final); + +int crypto_ahash_finup(struct ahash_request *req) +{ + return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); +} +EXPORT_SYMBOL_GPL(crypto_ahash_finup); + +int crypto_ahash_digest(struct ahash_request *req) +{ + return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest); +} +EXPORT_SYMBOL_GPL(crypto_ahash_digest); + +static void ahash_def_finup_finish2(struct ahash_request *req, int err) +{ + struct ahash_request_priv *priv = req->priv; + + if (err == -EINPROGRESS) + return; + + if (!err) + memcpy(priv->result, req->result, + crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); + + ahash_restore_req(req); +} + +static void ahash_def_finup_done2(struct crypto_async_request *req, int err) +{ + struct ahash_request *areq = req->data; + + ahash_def_finup_finish2(areq, err); + + areq->base.complete(&areq->base, err); +} + +static int ahash_def_finup_finish1(struct ahash_request *req, int err) +{ + if (err) + goto out; + + req->base.complete = ahash_def_finup_done2; + req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + err = crypto_ahash_reqtfm(req)->final(req); + +out: + ahash_def_finup_finish2(req, err); + return err; +} + +static void ahash_def_finup_done1(struct crypto_async_request *req, int err) +{ + struct ahash_request *areq = req->data; + + err = ahash_def_finup_finish1(areq, err); + + areq->base.complete(&areq->base, err); +} + +static int ahash_def_finup(struct ahash_request *req) +{ + struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); + int err; + + err = ahash_save_req(req, ahash_def_finup_done1); + if (err) + return err; + + err = tfm->update(req); + return ahash_def_finup_finish1(req, err); +} + +static int ahash_no_export(struct ahash_request *req, void *out) +{ + return -ENOSYS; +} + +static int ahash_no_import(struct ahash_request *req, const void *in) +{ + return -ENOSYS; +} + +static int crypto_ahash_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_ahash *hash = __crypto_ahash_cast(tfm); + struct ahash_alg *alg = crypto_ahash_alg(hash); + + hash->setkey = ahash_nosetkey; + hash->export = ahash_no_export; + hash->import = ahash_no_import; + + if (tfm->__crt_alg->cra_type != &crypto_ahash_type) + return crypto_init_shash_ops_async(tfm); + + hash->init = alg->init; + hash->update = alg->update; + hash->final = alg->final; + hash->finup = alg->finup ?: ahash_def_finup; + hash->digest = alg->digest; + + if (alg->setkey) + hash->setkey = alg->setkey; + if (alg->export) + hash->export = alg->export; + if (alg->import) + hash->import = alg->import; + + return 0; +} + +static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) +{ + if (alg->cra_type == &crypto_ahash_type) + return alg->cra_ctxsize; + + return sizeof(struct crypto_shash *); +} + +#ifdef CONFIG_NET +static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) +{ + struct crypto_report_hash rhash; + + strncpy(rhash.type, "ahash", sizeof(rhash.type)); + + rhash.blocksize = alg->cra_blocksize; + rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; + + if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, + sizeof(struct crypto_report_hash), &rhash)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -EMSGSIZE; +} +#else +static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) +{ + return -ENOSYS; +} +#endif + +static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) + __attribute__ ((unused)); +static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg) +{ + seq_printf(m, "type : ahash\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, "digestsize : %u\n", + __crypto_hash_alg_common(alg)->digestsize); +} + +const struct crypto_type crypto_ahash_type = { + .extsize = crypto_ahash_extsize, + .init_tfm = crypto_ahash_init_tfm, +#ifdef CONFIG_PROC_FS + .show = crypto_ahash_show, +#endif + .report = crypto_ahash_report, + .maskclear = ~CRYPTO_ALG_TYPE_MASK, + .maskset = CRYPTO_ALG_TYPE_AHASH_MASK, + .type = CRYPTO_ALG_TYPE_AHASH, + .tfmsize = offsetof(struct crypto_ahash, base), +}; +EXPORT_SYMBOL_GPL(crypto_ahash_type); + +struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type, + u32 mask) +{ + return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask); +} +EXPORT_SYMBOL_GPL(crypto_alloc_ahash); + +static int ahash_prepare_alg(struct ahash_alg *alg) +{ + struct crypto_alg *base = &alg->halg.base; + + if (alg->halg.digestsize > PAGE_SIZE / 8 || + alg->halg.statesize > PAGE_SIZE / 8) + return -EINVAL; + + base->cra_type = &crypto_ahash_type; + base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; + base->cra_flags |= CRYPTO_ALG_TYPE_AHASH; + + return 0; +} + +int crypto_register_ahash(struct ahash_alg *alg) +{ + struct crypto_alg *base = &alg->halg.base; + int err; + + err = ahash_prepare_alg(alg); + if (err) + return err; + + return crypto_register_alg(base); +} +EXPORT_SYMBOL_GPL(crypto_register_ahash); + +int crypto_unregister_ahash(struct ahash_alg *alg) +{ + return crypto_unregister_alg(&alg->halg.base); +} +EXPORT_SYMBOL_GPL(crypto_unregister_ahash); + +int ahash_register_instance(struct crypto_template *tmpl, + struct ahash_instance *inst) +{ + int err; + + err = ahash_prepare_alg(&inst->alg); + if (err) + return err; + + return crypto_register_instance(tmpl, ahash_crypto_instance(inst)); +} +EXPORT_SYMBOL_GPL(ahash_register_instance); + +void ahash_free_instance(struct crypto_instance *inst) +{ + crypto_drop_spawn(crypto_instance_ctx(inst)); + kfree(ahash_instance(inst)); +} +EXPORT_SYMBOL_GPL(ahash_free_instance); + +int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn, + struct hash_alg_common *alg, + struct crypto_instance *inst) +{ + return crypto_init_spawn2(&spawn->base, &alg->base, inst, + &crypto_ahash_type); +} +EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn); + +struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask) +{ + struct crypto_alg *alg; + + alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask); + return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg); +} +EXPORT_SYMBOL_GPL(ahash_attr_alg); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Asynchronous cryptographic hash type"); |