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/*

 * 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 <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"

#include "scatterwalk.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 > crypto_tfm_alg_blocksize(tfm))

                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)

{

}