digest.c

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/*
 * Cryptographic API.
 *
 * Digest operations.
 *
 * Copyright (c) 2002 James Morris <[email protected]>
 *
 * 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/crypto.h>
#include "rtl_crypto.h"
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/highmem.h>
#include <asm/scatterlist.h>
#include "internal.h"

static void init(struct crypto_tfm *tfm)
{
    tfm->__crt_alg->cra_digest.dia_init(crypto_tfm_ctx(tfm));
}

static void update(struct crypto_tfm *tfm,
           struct scatterlist *sg, unsigned int nsg)
{
    unsigned int i;

    for (i = 0; i < nsg; i++) {

        struct page *pg = sg[i].page;
        unsigned int offset = sg[i].offset;
        unsigned int l = sg[i].length;

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

            tfm->__crt_alg->cra_digest.dia_update
                    (crypto_tfm_ctx(tfm), p,
                     bytes_from_page);
            kunmap_atomic(p);
            crypto_yield(tfm);
            offset = 0;
            pg++;
            l -= bytes_from_page;
        } while (l > 0);
    }
}

static void final(struct crypto_tfm *tfm, u8 *out)
{
    tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), out);
}

static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
    u32 flags;
    if (tfm->__crt_alg->cra_digest.dia_setkey == NULL)
        return -ENOSYS;
    return tfm->__crt_alg->cra_digest.dia_setkey(crypto_tfm_ctx(tfm),
                             key, keylen, &flags);
}

static void digest(struct crypto_tfm *tfm,
           struct scatterlist *sg, unsigned int nsg, u8 *out)
{
    unsigned int i;

    tfm->crt_digest.dit_init(tfm);

    for (i = 0; i < nsg; i++) {
        char *p = kmap_atomic(sg[i].page) + sg[i].offset;
        tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
                              p, sg[i].length);
        kunmap_atomic(p);
        crypto_yield(tfm);
    }
    crypto_digest_final(tfm, out);
}

int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
{
    return flags ? -EINVAL : 0;
}

int crypto_init_digest_ops(struct crypto_tfm *tfm)
{
    struct digest_tfm *ops = &tfm->crt_digest;

    ops->dit_init   = init;
    ops->dit_update = update;
    ops->dit_final  = final;
    ops->dit_digest = digest;
    ops->dit_setkey = setkey;

    return crypto_alloc_hmac_block(tfm);
}

void crypto_exit_digest_ops(struct crypto_tfm *tfm)
{
    crypto_free_hmac_block(tfm);
}