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root/crypto/ablkcipher.c

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DEFINITIONS

This source file includes following definitions.
  1. setkey_unaligned
  2. setkey
  3. crypto_ablkcipher_ctxsize
  4. skcipher_null_givencrypt
  5. skcipher_null_givdecrypt
  6. crypto_init_ablkcipher_ops
  7. crypto_ablkcipher_show
  8. no_givdecrypt
  9. crypto_init_givcipher_ops
  10. crypto_givcipher_show
  11. crypto_default_geniv
  12. crypto_givcipher_default
  13. crypto_lookup_skcipher
  14. crypto_grab_skcipher
  15. crypto_alloc_ablkcipher

/*
 * Asynchronous block chaining cipher operations.
 * 
 * This is the asynchronous version of blkcipher.c indicating completion
 * via a callback.
 *
 * Copyright (c) 2006 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/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>

#include "internal.h"

static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
                            unsigned int keylen)
{
        struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
        unsigned long alignmask = crypto_ablkcipher_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 = cipher->setkey(tfm, alignbuffer, keylen);
        memset(alignbuffer, 0, keylen);
        kfree(buffer);
        return ret;
}

static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
                  unsigned int keylen)
{
        struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
        unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);

        if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
                crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
                return -EINVAL;
        }

        if ((unsigned long)key & alignmask)
                return setkey_unaligned(tfm, key, keylen);

        return cipher->setkey(tfm, key, keylen);
}

static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
                                              u32 mask)
{
        return alg->cra_ctxsize;
}

int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
{
        return crypto_ablkcipher_encrypt(&req->creq);
}

int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
{
        return crypto_ablkcipher_decrypt(&req->creq);
}

static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
                                      u32 mask)
{
        struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
        struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;

        if (alg->ivsize > PAGE_SIZE / 8)
                return -EINVAL;

        crt->setkey = setkey;
        crt->encrypt = alg->encrypt;
        crt->decrypt = alg->decrypt;
        if (!alg->ivsize) {
                crt->givencrypt = skcipher_null_givencrypt;
                crt->givdecrypt = skcipher_null_givdecrypt;
        }
        crt->base = __crypto_ablkcipher_cast(tfm);
        crt->ivsize = alg->ivsize;

        return 0;
}

static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
        __attribute__ ((unused));
static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
        struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;

        seq_printf(m, "type         : ablkcipher\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, "min keysize  : %u\n", ablkcipher->min_keysize);
        seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
        seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
        seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
}

const struct crypto_type crypto_ablkcipher_type = {
        .ctxsize = crypto_ablkcipher_ctxsize,
        .init = crypto_init_ablkcipher_ops,
#ifdef CONFIG_PROC_FS
        .show = crypto_ablkcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);

static int no_givdecrypt(struct skcipher_givcrypt_request *req)
{
        return -ENOSYS;
}

static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
                                      u32 mask)
{
        struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
        struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;

        if (alg->ivsize > PAGE_SIZE / 8)
                return -EINVAL;

        crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
                      alg->setkey : setkey;
        crt->encrypt = alg->encrypt;
        crt->decrypt = alg->decrypt;
        crt->givencrypt = alg->givencrypt;
        crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
        crt->base = __crypto_ablkcipher_cast(tfm);
        crt->ivsize = alg->ivsize;

        return 0;
}

static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
        __attribute__ ((unused));
static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
        struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;

        seq_printf(m, "type         : givcipher\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, "min keysize  : %u\n", ablkcipher->min_keysize);
        seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
        seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
        seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
}

const struct crypto_type crypto_givcipher_type = {
        .ctxsize = crypto_ablkcipher_ctxsize,
        .init = crypto_init_givcipher_ops,
#ifdef CONFIG_PROC_FS
        .show = crypto_givcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_givcipher_type);

const char *crypto_default_geniv(const struct crypto_alg *alg)
{
        return alg->cra_flags & CRYPTO_ALG_ASYNC ? "eseqiv" : "chainiv";
}

static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
{
        struct rtattr *tb[3];
        struct {
                struct rtattr attr;
                struct crypto_attr_type data;
        } ptype;
        struct {
                struct rtattr attr;
                struct crypto_attr_alg data;
        } palg;
        struct crypto_template *tmpl;
        struct crypto_instance *inst;
        struct crypto_alg *larval;
        const char *geniv;
        int err;

        larval = crypto_larval_lookup(alg->cra_driver_name,
                                      CRYPTO_ALG_TYPE_GIVCIPHER,
                                      CRYPTO_ALG_TYPE_MASK);
        err = PTR_ERR(larval);
        if (IS_ERR(larval))
                goto out;

        err = -EAGAIN;
        if (!crypto_is_larval(larval))
                goto drop_larval;

        ptype.attr.rta_len = sizeof(ptype);
        ptype.attr.rta_type = CRYPTOA_TYPE;
        ptype.data.type = type | CRYPTO_ALG_GENIV;
        /* GENIV tells the template that we're making a default geniv. */
        ptype.data.mask = mask | CRYPTO_ALG_GENIV;
        tb[0] = &ptype.attr;

        palg.attr.rta_len = sizeof(palg);
        palg.attr.rta_type = CRYPTOA_ALG;
        /* Must use the exact name to locate ourselves. */
        memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
        tb[1] = &palg.attr;

        tb[2] = NULL;

        if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
            CRYPTO_ALG_TYPE_BLKCIPHER)
                geniv = alg->cra_blkcipher.geniv;
        else
                geniv = alg->cra_ablkcipher.geniv;

        if (!geniv)
                geniv = crypto_default_geniv(alg);

        tmpl = crypto_lookup_template(geniv);
        err = -ENOENT;
        if (!tmpl)
                goto kill_larval;

        inst = tmpl->alloc(tb);
        err = PTR_ERR(inst);
        if (IS_ERR(inst))
                goto put_tmpl;

        if ((err = crypto_register_instance(tmpl, inst))) {
                tmpl->free(inst);
                goto put_tmpl;
        }

        /* Redo the lookup to use the instance we just registered. */
        err = -EAGAIN;

put_tmpl:
        crypto_tmpl_put(tmpl);
kill_larval:
        crypto_larval_kill(larval);
drop_larval:
        crypto_mod_put(larval);
out:
        crypto_mod_put(alg);
        return err;
}

static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
                                                 u32 mask)
{
        struct crypto_alg *alg;

        alg = crypto_alg_mod_lookup(name, type, mask);
        if (IS_ERR(alg))
                return alg;

        if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
            CRYPTO_ALG_TYPE_GIVCIPHER)
                return alg;

        if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
              CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
                                          alg->cra_ablkcipher.ivsize))
                return alg;

        return ERR_PTR(crypto_givcipher_default(alg, type, mask));
}

int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
                         u32 type, u32 mask)
{
        struct crypto_alg *alg;
        int err;

        type = crypto_skcipher_type(type);
        mask = crypto_skcipher_mask(mask);

        alg = crypto_lookup_skcipher(name, type, mask);
        if (IS_ERR(alg))
                return PTR_ERR(alg);

        err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
        crypto_mod_put(alg);
        return err;
}
EXPORT_SYMBOL_GPL(crypto_grab_skcipher);

struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
                                                  u32 type, u32 mask)
{
        struct crypto_tfm *tfm;
        int err;

        type = crypto_skcipher_type(type);
        mask = crypto_skcipher_mask(mask);

        for (;;) {
                struct crypto_alg *alg;

                alg = crypto_lookup_skcipher(alg_name, type, mask);
                if (IS_ERR(alg)) {
                        err = PTR_ERR(alg);
                        goto err;
                }

                tfm = __crypto_alloc_tfm(alg, type, mask);
                if (!IS_ERR(tfm))
                        return __crypto_ablkcipher_cast(tfm);

                crypto_mod_put(alg);
                err = PTR_ERR(tfm);

err:
                if (err != -EAGAIN)
                        break;
                if (signal_pending(current)) {
                        err = -EINTR;
                        break;
                }
        }

        return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);

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