diff options
Diffstat (limited to 'crypto/ahash.c')
| -rw-r--r-- | crypto/ahash.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/crypto/ahash.c b/crypto/ahash.c new file mode 100644 index 000000000000..27128f2c687a --- /dev/null +++ b/crypto/ahash.c @@ -0,0 +1,194 @@ +/* + * 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"); |