linux/crypto/shash.c
Herbert Xu 3f683d6175 crypto: api - Fix crypto_alloc_tfm/create_create_tfm return convention
This is based on a report and patch by Geert Uytterhoeven.

The functions crypto_alloc_tfm and create_create_tfm return a
pointer that needs to be adjusted by the caller when successful
and otherwise an error value.  This means that the caller has
to check for the error and only perform the adjustment if the
pointer returned is valid.

Since all callers want to make the adjustment and we know how
to adjust it ourselves, it's much easier to just return adjusted
pointer directly.

The only caveat is that we have to return a void * instead of
struct crypto_tfm *.  However, this isn't that bad because both
of these functions are for internal use only (by types code like
shash.c, not even algorithms code).

This patch also moves crypto_alloc_tfm into crypto/internal.h
(crypto_create_tfm is already there) to reflect this.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-18 16:56:59 +08:00

504 lines
13 KiB
C

/*
* Synchronous Cryptographic Hash operations.
*
* Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
*
* 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/scatterwalk.h>
#include <crypto/internal/hash.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include "internal.h"
static const struct crypto_type crypto_shash_type;
static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
unsigned int keylen)
{
struct shash_alg *shash = crypto_shash_alg(tfm);
unsigned long alignmask = crypto_shash_alignmask(tfm);
unsigned long absize;
u8 *buffer, *alignbuffer;
int err;
absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
buffer = kmalloc(absize, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
err = shash->setkey(tfm, alignbuffer, keylen);
memset(alignbuffer, 0, keylen);
kfree(buffer);
return err;
}
int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
unsigned int keylen)
{
struct shash_alg *shash = crypto_shash_alg(tfm);
unsigned long alignmask = crypto_shash_alignmask(tfm);
if (!shash->setkey)
return -ENOSYS;
if ((unsigned long)key & alignmask)
return shash_setkey_unaligned(tfm, key, keylen);
return shash->setkey(tfm, key, keylen);
}
EXPORT_SYMBOL_GPL(crypto_shash_setkey);
static inline unsigned int shash_align_buffer_size(unsigned len,
unsigned long mask)
{
return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
}
static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct crypto_shash *tfm = desc->tfm;
struct shash_alg *shash = crypto_shash_alg(tfm);
unsigned long alignmask = crypto_shash_alignmask(tfm);
unsigned int unaligned_len = alignmask + 1 -
((unsigned long)data & alignmask);
u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
__attribute__ ((aligned));
memcpy(buf, data, unaligned_len);
return shash->update(desc, buf, unaligned_len) ?:
shash->update(desc, data + unaligned_len, len - unaligned_len);
}
int crypto_shash_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct crypto_shash *tfm = desc->tfm;
struct shash_alg *shash = crypto_shash_alg(tfm);
unsigned long alignmask = crypto_shash_alignmask(tfm);
if ((unsigned long)data & alignmask)
return shash_update_unaligned(desc, data, len);
return shash->update(desc, data, len);
}
EXPORT_SYMBOL_GPL(crypto_shash_update);
static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
{
struct crypto_shash *tfm = desc->tfm;
unsigned long alignmask = crypto_shash_alignmask(tfm);
struct shash_alg *shash = crypto_shash_alg(tfm);
unsigned int ds = crypto_shash_digestsize(tfm);
u8 buf[shash_align_buffer_size(ds, alignmask)]
__attribute__ ((aligned));
int err;
err = shash->final(desc, buf);
memcpy(out, buf, ds);
return err;
}
int crypto_shash_final(struct shash_desc *desc, u8 *out)
{
struct crypto_shash *tfm = desc->tfm;
struct shash_alg *shash = crypto_shash_alg(tfm);
unsigned long alignmask = crypto_shash_alignmask(tfm);
if ((unsigned long)out & alignmask)
return shash_final_unaligned(desc, out);
return shash->final(desc, out);
}
EXPORT_SYMBOL_GPL(crypto_shash_final);
static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
return crypto_shash_update(desc, data, len) ?:
crypto_shash_final(desc, out);
}
int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
struct crypto_shash *tfm = desc->tfm;
struct shash_alg *shash = crypto_shash_alg(tfm);
unsigned long alignmask = crypto_shash_alignmask(tfm);
if (((unsigned long)data | (unsigned long)out) & alignmask ||
!shash->finup)
return shash_finup_unaligned(desc, data, len, out);
return shash->finup(desc, data, len, out);
}
EXPORT_SYMBOL_GPL(crypto_shash_finup);
static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
return crypto_shash_init(desc) ?:
crypto_shash_update(desc, data, len) ?:
crypto_shash_final(desc, out);
}
int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
struct crypto_shash *tfm = desc->tfm;
struct shash_alg *shash = crypto_shash_alg(tfm);
unsigned long alignmask = crypto_shash_alignmask(tfm);
if (((unsigned long)data | (unsigned long)out) & alignmask ||
!shash->digest)
return shash_digest_unaligned(desc, data, len, out);
return shash->digest(desc, data, len, out);
}
EXPORT_SYMBOL_GPL(crypto_shash_digest);
int crypto_shash_import(struct shash_desc *desc, const u8 *in)
{
struct crypto_shash *tfm = desc->tfm;
struct shash_alg *alg = crypto_shash_alg(tfm);
memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
if (alg->reinit)
alg->reinit(desc);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_shash_import);
static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int keylen)
{
struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
return crypto_shash_setkey(*ctx, key, keylen);
}
static int shash_async_init(struct ahash_request *req)
{
struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
struct shash_desc *desc = ahash_request_ctx(req);
desc->tfm = *ctx;
desc->flags = req->base.flags;
return crypto_shash_init(desc);
}
static int shash_async_update(struct ahash_request *req)
{
struct shash_desc *desc = ahash_request_ctx(req);
struct crypto_hash_walk walk;
int nbytes;
for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
nbytes = crypto_hash_walk_done(&walk, nbytes))
nbytes = crypto_shash_update(desc, walk.data, nbytes);
return nbytes;
}
static int shash_async_final(struct ahash_request *req)
{
return crypto_shash_final(ahash_request_ctx(req), req->result);
}
static int shash_async_digest(struct ahash_request *req)
{
struct scatterlist *sg = req->src;
unsigned int offset = sg->offset;
unsigned int nbytes = req->nbytes;
int err;
if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
struct crypto_shash **ctx =
crypto_ahash_ctx(crypto_ahash_reqtfm(req));
struct shash_desc *desc = ahash_request_ctx(req);
void *data;
desc->tfm = *ctx;
desc->flags = req->base.flags;
data = crypto_kmap(sg_page(sg), 0);
err = crypto_shash_digest(desc, data + offset, nbytes,
req->result);
crypto_kunmap(data, 0);
crypto_yield(desc->flags);
goto out;
}
err = shash_async_init(req);
if (err)
goto out;
err = shash_async_update(req);
if (err)
goto out;
err = shash_async_final(req);
out:
return err;
}
static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
{
struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
crypto_free_shash(*ctx);
}
static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
{
struct crypto_alg *calg = tfm->__crt_alg;
struct shash_alg *alg = __crypto_shash_alg(calg);
struct ahash_tfm *crt = &tfm->crt_ahash;
struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
struct crypto_shash *shash;
if (!crypto_mod_get(calg))
return -EAGAIN;
shash = crypto_create_tfm(calg, &crypto_shash_type);
if (IS_ERR(shash)) {
crypto_mod_put(calg);
return PTR_ERR(shash);
}
*ctx = shash;
tfm->exit = crypto_exit_shash_ops_async;
crt->init = shash_async_init;
crt->update = shash_async_update;
crt->final = shash_async_final;
crt->digest = shash_async_digest;
crt->setkey = shash_async_setkey;
crt->digestsize = alg->digestsize;
crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
return 0;
}
static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
unsigned int keylen)
{
struct shash_desc *desc = crypto_hash_ctx(tfm);
return crypto_shash_setkey(desc->tfm, key, keylen);
}
static int shash_compat_init(struct hash_desc *hdesc)
{
struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
desc->flags = hdesc->flags;
return crypto_shash_init(desc);
}
static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
unsigned int len)
{
struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
struct crypto_hash_walk walk;
int nbytes;
for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
nbytes = crypto_shash_update(desc, walk.data, nbytes);
return nbytes;
}
static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
{
return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
}
static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
unsigned int nbytes, u8 *out)
{
unsigned int offset = sg->offset;
int err;
if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
void *data;
desc->flags = hdesc->flags;
data = crypto_kmap(sg_page(sg), 0);
err = crypto_shash_digest(desc, data + offset, nbytes, out);
crypto_kunmap(data, 0);
crypto_yield(desc->flags);
goto out;
}
err = shash_compat_init(hdesc);
if (err)
goto out;
err = shash_compat_update(hdesc, sg, nbytes);
if (err)
goto out;
err = shash_compat_final(hdesc, out);
out:
return err;
}
static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
{
struct shash_desc *desc= crypto_tfm_ctx(tfm);
crypto_free_shash(desc->tfm);
}
static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
{
struct hash_tfm *crt = &tfm->crt_hash;
struct crypto_alg *calg = tfm->__crt_alg;
struct shash_alg *alg = __crypto_shash_alg(calg);
struct shash_desc *desc = crypto_tfm_ctx(tfm);
struct crypto_shash *shash;
if (!crypto_mod_get(calg))
return -EAGAIN;
shash = crypto_create_tfm(calg, &crypto_shash_type);
if (IS_ERR(shash)) {
crypto_mod_put(calg);
return PTR_ERR(shash);
}
desc->tfm = shash;
tfm->exit = crypto_exit_shash_ops_compat;
crt->init = shash_compat_init;
crt->update = shash_compat_update;
crt->final = shash_compat_final;
crt->digest = shash_compat_digest;
crt->setkey = shash_compat_setkey;
crt->digestsize = alg->digestsize;
return 0;
}
static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
switch (mask & CRYPTO_ALG_TYPE_MASK) {
case CRYPTO_ALG_TYPE_HASH_MASK:
return crypto_init_shash_ops_compat(tfm);
case CRYPTO_ALG_TYPE_AHASH_MASK:
return crypto_init_shash_ops_async(tfm);
}
return -EINVAL;
}
static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
u32 mask)
{
struct shash_alg *salg = __crypto_shash_alg(alg);
switch (mask & CRYPTO_ALG_TYPE_MASK) {
case CRYPTO_ALG_TYPE_HASH_MASK:
return sizeof(struct shash_desc) + salg->descsize;
case CRYPTO_ALG_TYPE_AHASH_MASK:
return sizeof(struct crypto_shash *);
}
return 0;
}
static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
const struct crypto_type *frontend)
{
return 0;
}
static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
const struct crypto_type *frontend)
{
return alg->cra_ctxsize;
}
static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
{
struct shash_alg *salg = __crypto_shash_alg(alg);
seq_printf(m, "type : shash\n");
seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
seq_printf(m, "digestsize : %u\n", salg->digestsize);
seq_printf(m, "descsize : %u\n", salg->descsize);
}
static const struct crypto_type crypto_shash_type = {
.ctxsize = crypto_shash_ctxsize,
.extsize = crypto_shash_extsize,
.init = crypto_init_shash_ops,
.init_tfm = crypto_shash_init_tfm,
#ifdef CONFIG_PROC_FS
.show = crypto_shash_show,
#endif
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_MASK,
.type = CRYPTO_ALG_TYPE_SHASH,
.tfmsize = offsetof(struct crypto_shash, base),
};
struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
u32 mask)
{
return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_shash);
int crypto_register_shash(struct shash_alg *alg)
{
struct crypto_alg *base = &alg->base;
if (alg->digestsize > PAGE_SIZE / 8 ||
alg->descsize > PAGE_SIZE / 8)
return -EINVAL;
base->cra_type = &crypto_shash_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_shash);
int crypto_unregister_shash(struct shash_alg *alg)
{
return crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_shash);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Synchronous cryptographic hash type");