// SPDX-License-Identifier: GPL-2.0-or-later /* * 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> */ #include <crypto/internal/hash.h> #include <crypto/scatterwalk.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 <linux/compiler.h> #include <net/netlink.h> #include "internal.h" static const struct crypto_type crypto_ahash_type; struct ahash_request_priv { crypto_completion_t complete; void *data; u8 *result; u32 flags; 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); 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->offset = sg->offset; walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); walk->offset = offset_in_page(walk->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; walk->data -= walk->offset; if (walk->entrylen && (walk->offset & alignmask) && !err) { unsigned int nbytes; walk->offset = ALIGN(walk->offset, alignmask + 1); nbytes = min(walk->entrylen, (unsigned int)(PAGE_SIZE - walk->offset)); if (nbytes) { walk->entrylen -= nbytes; walk->data += walk->offset; return nbytes; } } kunmap_atomic(walk->data); crypto_yield(walk->flags); if (err) return err; if (walk->entrylen) { 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; return hash_walk_new_entry(walk); } EXPORT_SYMBOL_GPL(crypto_hash_walk_first); 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); kfree_sensitive(buffer); return ret; } static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key, unsigned int keylen) { return -ENOSYS; } static void ahash_set_needkey(struct crypto_ahash *tfm) { const struct hash_alg_common *alg = crypto_hash_alg_common(tfm); if (tfm->setkey != ahash_nosetkey && !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY)) crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY); } int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, unsigned int keylen) { unsigned long alignmask = crypto_ahash_alignmask(tfm); int err; if ((unsigned long)key & alignmask) err = ahash_setkey_unaligned(tfm, key, keylen); else err = tfm->setkey(tfm, key, keylen); if (unlikely(err)) { ahash_set_needkey(tfm); return err; } crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); return 0; } EXPORT_SYMBOL_GPL(crypto_ahash_setkey); 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; priv->flags = req->base.flags; /* * 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, int err) { struct ahash_request_priv *priv = req->priv; if (!err) memcpy(priv->result, req->result, crypto_ahash_digestsize(crypto_ahash_reqtfm(req))); /* Restore the original crypto request. */ req->result = priv->result; ahash_request_set_callback(req, priv->flags, priv->complete, priv->data); req->priv = NULL; /* Free the req->priv.priv from the ADJUSTED request. */ kfree_sensitive(priv); } static void ahash_notify_einprogress(struct ahash_request *req) { struct ahash_request_priv *priv = req->priv; struct crypto_async_request oreq; oreq.data = priv->data; priv->complete(&oreq, -EINPROGRESS); } static void ahash_op_unaligned_done(struct crypto_async_request *req, int err) { struct ahash_request *areq = req->data; if (err == -EINPROGRESS) { ahash_notify_einprogress(areq); return; } /* * 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_restore_req(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); if (err == -EINPROGRESS || err == -EBUSY) return err; ahash_restore_req(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) { struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); struct crypto_alg *alg = tfm->base.__crt_alg; unsigned int nbytes = req->nbytes; int ret; crypto_stats_get(alg); ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final); crypto_stats_ahash_final(nbytes, ret, alg); return ret; } EXPORT_SYMBOL_GPL(crypto_ahash_final); int crypto_ahash_finup(struct ahash_request *req) { struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); struct crypto_alg *alg = tfm->base.__crt_alg; unsigned int nbytes = req->nbytes; int ret; crypto_stats_get(alg); ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup); crypto_stats_ahash_final(nbytes, ret, alg); return ret; } EXPORT_SYMBOL_GPL(crypto_ahash_finup); int crypto_ahash_digest(struct ahash_request *req) { struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); struct crypto_alg *alg = tfm->base.__crt_alg; unsigned int nbytes = req->nbytes; int ret; crypto_stats_get(alg); if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) ret = -ENOKEY; else ret = crypto_ahash_op(req, tfm->digest); crypto_stats_ahash_final(nbytes, ret, alg); return ret; } EXPORT_SYMBOL_GPL(crypto_ahash_digest); static void ahash_def_finup_done2(struct crypto_async_request *req, int err) { struct ahash_request *areq = req->data; if (err == -EINPROGRESS) return; ahash_restore_req(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; err = crypto_ahash_reqtfm(req)->final(req); if (err == -EINPROGRESS || err == -EBUSY) return err; out: ahash_restore_req(req, err); return err; } static void ahash_def_finup_done1(struct crypto_async_request *req, int err) { struct ahash_request *areq = req->data; if (err == -EINPROGRESS) { ahash_notify_einprogress(areq); return; } areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; err = ahash_def_finup_finish1(areq, err); if (areq->priv) return; 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); if (err == -EINPROGRESS || err == -EBUSY) return err; return ahash_def_finup_finish1(req, err); } static void crypto_ahash_exit_tfm(struct crypto_tfm *tfm) { struct crypto_ahash *hash = __crypto_ahash_cast(tfm); struct ahash_alg *alg = crypto_ahash_alg(hash); alg->exit_tfm(hash); } 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; 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; hash->export = alg->export; hash->import = alg->import; if (alg->setkey) { hash->setkey = alg->setkey; ahash_set_needkey(hash); } if (alg->exit_tfm) tfm->exit = crypto_ahash_exit_tfm; return alg->init_tfm ? alg->init_tfm(hash) : 0; } static unsigned int crypto_ahash_extsize(struct crypto_alg *alg) { if (alg->cra_type != &crypto_ahash_type) return sizeof(struct crypto_shash *); return crypto_alg_extsize(alg); } static void crypto_ahash_free_instance(struct crypto_instance *inst) { struct ahash_instance *ahash = ahash_instance(inst); ahash->free(ahash); } #ifdef CONFIG_NET static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_hash rhash; memset(&rhash, 0, sizeof(rhash)); strscpy(rhash.type, "ahash", sizeof(rhash.type)); rhash.blocksize = alg->cra_blocksize; rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash); } #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) __maybe_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); } static const struct crypto_type crypto_ahash_type = { .extsize = crypto_ahash_extsize, .init_tfm = crypto_ahash_init_tfm, .free = crypto_ahash_free_instance, #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), }; int crypto_grab_ahash(struct crypto_ahash_spawn *spawn, struct crypto_instance *inst, const char *name, u32 type, u32 mask) { spawn->base.frontend = &crypto_ahash_type; return crypto_grab_spawn(&spawn->base, inst, name, type, mask); } EXPORT_SYMBOL_GPL(crypto_grab_ahash); 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); int crypto_has_ahash(const char *alg_name, u32 type, u32 mask) { return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask); } EXPORT_SYMBOL_GPL(crypto_has_ahash); static int ahash_prepare_alg(struct ahash_alg *alg) { struct crypto_alg *base = &alg->halg.base; if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE || alg->halg.statesize > HASH_MAX_STATESIZE || alg->halg.statesize == 0) 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); void crypto_unregister_ahash(struct ahash_alg *alg) { crypto_unregister_alg(&alg->halg.base); } EXPORT_SYMBOL_GPL(crypto_unregister_ahash); int crypto_register_ahashes(struct ahash_alg *algs, int count) { int i, ret; for (i = 0; i < count; i++) { ret = crypto_register_ahash(&algs[i]); if (ret) goto err; } return 0; err: for (--i; i >= 0; --i) crypto_unregister_ahash(&algs[i]); return ret; } EXPORT_SYMBOL_GPL(crypto_register_ahashes); void crypto_unregister_ahashes(struct ahash_alg *algs, int count) { int i; for (i = count - 1; i >= 0; --i) crypto_unregister_ahash(&algs[i]); } EXPORT_SYMBOL_GPL(crypto_unregister_ahashes); int ahash_register_instance(struct crypto_template *tmpl, struct ahash_instance *inst) { int err; if (WARN_ON(!inst->free)) return -EINVAL; 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); bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg) { struct crypto_alg *alg = &halg->base; if (alg->cra_type != &crypto_ahash_type) return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg)); return __crypto_ahash_alg(alg)->setkey != NULL; } EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Asynchronous cryptographic hash type");