root/crypto/digest.c

DEFINITIONS

1. init
2. update2
3. update
4. final
5. nosetkey
6. setkey
7. digest
8. crypto_init_digest_ops
9. crypto_exit_digest_ops
10. digest_async_nosetkey
11. digest_async_setkey
12. digest_async_init
13. digest_async_update
14. digest_async_final
15. digest_async_digest
16. crypto_init_digest_ops_async

/*
 * Cryptographic API.
 *
 * Digest operations.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.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/internal/hash.h>
#include <crypto/scatterwalk.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>

#include "internal.h"

static int init(struct hash_desc *desc)
{
        struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);

        tfm->__crt_alg->cra_digest.dia_init(tfm);
        return 0;
}

static int update2(struct hash_desc *desc,
                   struct scatterlist *sg, unsigned int nbytes)
{
        struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
        unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);

        if (!nbytes)
                return 0;

        for (;;) {
                struct page *pg = sg_page(sg);
                unsigned int offset = sg->offset;
                unsigned int l = sg->length;

                if (unlikely(l > nbytes))
                        l = nbytes;
                nbytes -= l;

                do {
                        unsigned int bytes_from_page = min(l, ((unsigned int)
                                                           (PAGE_SIZE)) - 
                                                           offset);
                        char *src = crypto_kmap(pg, 0);
                        char *p = src + offset;

                        if (unlikely(offset & alignmask)) {
                                unsigned int bytes =
                                        alignmask + 1 - (offset & alignmask);
                                bytes = min(bytes, bytes_from_page);
                                tfm->__crt_alg->cra_digest.dia_update(tfm, p,
                                                                      bytes);
                                p += bytes;
                                bytes_from_page -= bytes;
                                l -= bytes;
                        }
                        tfm->__crt_alg->cra_digest.dia_update(tfm, p,
                                                              bytes_from_page);
                        crypto_kunmap(src, 0);
                        crypto_yield(desc->flags);
                        offset = 0;
                        pg++;
                        l -= bytes_from_page;
                } while (l > 0);

                if (!nbytes)
                        break;
                sg = scatterwalk_sg_next(sg);
        }

        return 0;
}

static int update(struct hash_desc *desc,
                  struct scatterlist *sg, unsigned int nbytes)
{
        if (WARN_ON_ONCE(in_irq()))
                return -EDEADLK;
        return update2(desc, sg, nbytes);
}

static int final(struct hash_desc *desc, u8 *out)
{
        struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
        struct digest_alg *digest = &tfm->__crt_alg->cra_digest;

        if (unlikely((unsigned long)out & alignmask)) {
                unsigned long align = alignmask + 1;
                unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
                u8 *dst = (u8 *)ALIGN(addr, align) +
                          ALIGN(tfm->__crt_alg->cra_ctxsize, align);

                digest->dia_final(tfm, dst);
                memcpy(out, dst, digest->dia_digestsize);
        } else
                digest->dia_final(tfm, out);

        return 0;
}

static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
{
        crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
        return -ENOSYS;
}

static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
{
        struct crypto_tfm *tfm = crypto_hash_tfm(hash);

        crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
        return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
}

static int digest(struct hash_desc *desc,
                  struct scatterlist *sg, unsigned int nbytes, u8 *out)
{
        if (WARN_ON_ONCE(in_irq()))
                return -EDEADLK;

        init(desc);
        update2(desc, sg, nbytes);
        return final(desc, out);
}

int crypto_init_digest_ops(struct crypto_tfm *tfm)
{
        struct hash_tfm *ops = &tfm->crt_hash;
        struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;

        if (dalg->dia_digestsize > PAGE_SIZE / 8)
                return -EINVAL;
        
        ops->init       = init;
        ops->update     = update;
        ops->final      = final;
        ops->digest     = digest;
        ops->setkey     = dalg->dia_setkey ? setkey : nosetkey;
        ops->digestsize = dalg->dia_digestsize;
        
        return 0;
}

void crypto_exit_digest_ops(struct crypto_tfm *tfm)
{
}

static int digest_async_nosetkey(struct crypto_ahash *tfm_async, const u8 *key,
                        unsigned int keylen)
{
        crypto_ahash_clear_flags(tfm_async, CRYPTO_TFM_RES_MASK);
        return -ENOSYS;
}

static int digest_async_setkey(struct crypto_ahash *tfm_async, const u8 *key,
                        unsigned int keylen)
{
        struct crypto_tfm    *tfm        = crypto_ahash_tfm(tfm_async);
        struct digest_alg    *dalg       = &tfm->__crt_alg->cra_digest;

        crypto_ahash_clear_flags(tfm_async, CRYPTO_TFM_RES_MASK);
        return dalg->dia_setkey(tfm, key, keylen);
}

static int digest_async_init(struct ahash_request *req)
{
        struct crypto_tfm *tfm  = req->base.tfm;
        struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;

        dalg->dia_init(tfm);
        return 0;
}

static int digest_async_update(struct ahash_request *req)
{
        struct crypto_tfm *tfm = req->base.tfm;
        struct hash_desc  desc = {
                .tfm   = __crypto_hash_cast(tfm),
                .flags = req->base.flags,
        };

        update(&desc, req->src, req->nbytes);
        return 0;
}

static int digest_async_final(struct ahash_request *req)
{
        struct crypto_tfm *tfm  = req->base.tfm;
        struct hash_desc  desc = {
                .tfm   = __crypto_hash_cast(tfm),
                .flags = req->base.flags,
        };

        final(&desc, req->result);
        return 0;
}

static int digest_async_digest(struct ahash_request *req)
{
        struct crypto_tfm *tfm  = req->base.tfm;
        struct hash_desc  desc = {
                .tfm   = __crypto_hash_cast(tfm),
                .flags = req->base.flags,
        };

        return digest(&desc, req->src, req->nbytes, req->result);
}

int crypto_init_digest_ops_async(struct crypto_tfm *tfm)
{
        struct ahash_tfm  *crt  = &tfm->crt_ahash;
        struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;

        if (dalg->dia_digestsize > PAGE_SIZE / 8)
                return -EINVAL;

        crt->init       = digest_async_init;
        crt->update     = digest_async_update;
        crt->final      = digest_async_final;
        crt->digest     = digest_async_digest;
        crt->setkey     = dalg->dia_setkey ? digest_async_setkey :
                                                digest_async_nosetkey;
        crt->digestsize = dalg->dia_digestsize;

        return 0;
}