/* * 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/err.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/seq_file.h> #include "internal.h" 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 = crypto_kmap(walk->pg, 0); walk->data += offset; if (offset & alignmask) nbytes = alignmask + 1 - (offset & alignmask); 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 += alignmask - 1; 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; } crypto_kunmap(walk->data, 0); crypto_yield(walk->flags); if (err) return err; walk->offset = 0; if (nbytes) return hash_walk_next(walk); if (!walk->total) return 0; walk->sg = scatterwalk_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) 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) { struct ahash_alg *ahash = crypto_ahash_alg(tfm); unsigned long alignmask = crypto_ahash_alignmask(tfm); int ret; u8 *buffer, *alignbuffer; unsigned long absize; 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 = ahash->setkey(tfm, alignbuffer, keylen); memset(alignbuffer, 0, keylen); kfree(buffer); return ret; } static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key, unsigned int keylen) { struct ahash_alg *ahash = crypto_ahash_alg(tfm); unsigned long alignmask = crypto_ahash_alignmask(tfm); if ((unsigned long)key & alignmask) return ahash_setkey_unaligned(tfm, key, keylen); return ahash->setkey(tfm, key, keylen); } static unsigned int crypto_ahash_ctxsize(struct crypto_alg *alg, u32 type, u32 mask) { return alg->cra_ctxsize; } static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask) { struct ahash_alg *alg = &tfm->__crt_alg->cra_ahash; struct ahash_tfm *crt = &tfm->crt_ahash; if (alg->digestsize > PAGE_SIZE / 8) return -EINVAL; crt->init = alg->init; crt->update = alg->update; crt->final = alg->final; crt->digest = alg->digest; crt->setkey = ahash_setkey; crt->digestsize = alg->digestsize; return 0; } 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", alg->cra_hash.digestsize); } const struct crypto_type crypto_ahash_type = { .ctxsize = crypto_ahash_ctxsize, .init = crypto_init_ahash_ops, #ifdef CONFIG_PROC_FS .show = crypto_ahash_show, #endif }; EXPORT_SYMBOL_GPL(crypto_ahash_type); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Asynchronous cryptographic hash type");