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root/crypto/aead.c

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DEFINITIONS

This source file includes following definitions.
  1. setkey_unaligned
  2. setkey
  3. crypto_aead_setauthsize
  4. crypto_aead_ctxsize
  5. no_givcrypt
  6. crypto_init_aead_ops
  7. crypto_aead_show
  8. aead_null_givencrypt
  9. aead_null_givdecrypt
  10. crypto_init_nivaead_ops
  11. crypto_nivaead_show
  12. crypto_grab_nivaead
  13. aead_geniv_alloc
  14. aead_geniv_free
  15. aead_geniv_init
  16. aead_geniv_exit
  17. crypto_nivaead_default
  18. crypto_lookup_aead
  19. crypto_grab_aead
  20. crypto_alloc_aead

/*
 * AEAD: Authenticated Encryption with Associated Data
 * 
 * This file provides API support for AEAD algorithms.
 *
 * Copyright (c) 2007 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/aead.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/seq_file.h>

#include "internal.h"

static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
                            unsigned int keylen)
{
        struct aead_alg *aead = crypto_aead_alg(tfm);
        unsigned long alignmask = crypto_aead_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 = aead->setkey(tfm, alignbuffer, keylen);
        memset(alignbuffer, 0, keylen);
        kfree(buffer);
        return ret;
}

static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
{
        struct aead_alg *aead = crypto_aead_alg(tfm);
        unsigned long alignmask = crypto_aead_alignmask(tfm);

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

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

int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
{
        struct aead_tfm *crt = crypto_aead_crt(tfm);
        int err;

        if (authsize > crypto_aead_alg(tfm)->maxauthsize)
                return -EINVAL;

        if (crypto_aead_alg(tfm)->setauthsize) {
                err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize);
                if (err)
                        return err;
        }

        crypto_aead_crt(crt->base)->authsize = authsize;
        crt->authsize = authsize;
        return 0;
}
EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);

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

static int no_givcrypt(struct aead_givcrypt_request *req)
{
        return -ENOSYS;
}

static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
        struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
        struct aead_tfm *crt = &tfm->crt_aead;

        if (max(alg->maxauthsize, 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 ?: no_givcrypt;
        crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
        crt->base = __crypto_aead_cast(tfm);
        crt->ivsize = alg->ivsize;
        crt->authsize = alg->maxauthsize;

        return 0;
}

static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
        __attribute__ ((unused));
static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
{
        struct aead_alg *aead = &alg->cra_aead;

        seq_printf(m, "type         : aead\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, "ivsize       : %u\n", aead->ivsize);
        seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
        seq_printf(m, "geniv        : %s\n", aead->geniv ?: "<built-in>");
}

const struct crypto_type crypto_aead_type = {
        .ctxsize = crypto_aead_ctxsize,
        .init = crypto_init_aead_ops,
#ifdef CONFIG_PROC_FS
        .show = crypto_aead_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_aead_type);

static int aead_null_givencrypt(struct aead_givcrypt_request *req)
{
        return crypto_aead_encrypt(&req->areq);
}

static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
{
        return crypto_aead_decrypt(&req->areq);
}

static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
        struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
        struct aead_tfm *crt = &tfm->crt_aead;

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

        crt->setkey = setkey;
        crt->encrypt = alg->encrypt;
        crt->decrypt = alg->decrypt;
        if (!alg->ivsize) {
                crt->givencrypt = aead_null_givencrypt;
                crt->givdecrypt = aead_null_givdecrypt;
        }
        crt->base = __crypto_aead_cast(tfm);
        crt->ivsize = alg->ivsize;
        crt->authsize = alg->maxauthsize;

        return 0;
}

static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
        __attribute__ ((unused));
static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
{
        struct aead_alg *aead = &alg->cra_aead;

        seq_printf(m, "type         : nivaead\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, "ivsize       : %u\n", aead->ivsize);
        seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
        seq_printf(m, "geniv        : %s\n", aead->geniv);
}

const struct crypto_type crypto_nivaead_type = {
        .ctxsize = crypto_aead_ctxsize,
        .init = crypto_init_nivaead_ops,
#ifdef CONFIG_PROC_FS
        .show = crypto_nivaead_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_nivaead_type);

static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
                               const char *name, u32 type, u32 mask)
{
        struct crypto_alg *alg;
        int err;

        type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
        type |= CRYPTO_ALG_TYPE_AEAD;
        mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;

        alg = crypto_alg_mod_lookup(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;
}

struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
                                         struct rtattr **tb, u32 type,
                                         u32 mask)
{
        const char *name;
        struct crypto_aead_spawn *spawn;
        struct crypto_attr_type *algt;
        struct crypto_instance *inst;
        struct crypto_alg *alg;
        int err;

        algt = crypto_get_attr_type(tb);
        err = PTR_ERR(algt);
        if (IS_ERR(algt))
                return ERR_PTR(err);

        if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
            algt->mask)
                return ERR_PTR(-EINVAL);

        name = crypto_attr_alg_name(tb[1]);
        err = PTR_ERR(name);
        if (IS_ERR(name))
                return ERR_PTR(err);

        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
        if (!inst)
                return ERR_PTR(-ENOMEM);

        spawn = crypto_instance_ctx(inst);

        /* Ignore async algorithms if necessary. */
        mask |= crypto_requires_sync(algt->type, algt->mask);

        crypto_set_aead_spawn(spawn, inst);
        err = crypto_grab_nivaead(spawn, name, type, mask);
        if (err)
                goto err_free_inst;

        alg = crypto_aead_spawn_alg(spawn);

        err = -EINVAL;
        if (!alg->cra_aead.ivsize)
                goto err_drop_alg;

        /*
         * This is only true if we're constructing an algorithm with its
         * default IV generator.  For the default generator we elide the
         * template name and double-check the IV generator.
         */
        if (algt->mask & CRYPTO_ALG_GENIV) {
                if (strcmp(tmpl->name, alg->cra_aead.geniv))
                        goto err_drop_alg;

                memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
                memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
                       CRYPTO_MAX_ALG_NAME);
        } else {
                err = -ENAMETOOLONG;
                if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
                             "%s(%s)", tmpl->name, alg->cra_name) >=
                    CRYPTO_MAX_ALG_NAME)
                        goto err_drop_alg;
                if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
                             "%s(%s)", tmpl->name, alg->cra_driver_name) >=
                    CRYPTO_MAX_ALG_NAME)
                        goto err_drop_alg;
        }

        inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
        inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
        inst->alg.cra_priority = alg->cra_priority;
        inst->alg.cra_blocksize = alg->cra_blocksize;
        inst->alg.cra_alignmask = alg->cra_alignmask;
        inst->alg.cra_type = &crypto_aead_type;

        inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
        inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
        inst->alg.cra_aead.geniv = alg->cra_aead.geniv;

        inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
        inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
        inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
        inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;

out:
        return inst;

err_drop_alg:
        crypto_drop_aead(spawn);
err_free_inst:
        kfree(inst);
        inst = ERR_PTR(err);
        goto out;
}
EXPORT_SYMBOL_GPL(aead_geniv_alloc);

void aead_geniv_free(struct crypto_instance *inst)
{
        crypto_drop_aead(crypto_instance_ctx(inst));
        kfree(inst);
}
EXPORT_SYMBOL_GPL(aead_geniv_free);

int aead_geniv_init(struct crypto_tfm *tfm)
{
        struct crypto_instance *inst = (void *)tfm->__crt_alg;
        struct crypto_aead *aead;

        aead = crypto_spawn_aead(crypto_instance_ctx(inst));
        if (IS_ERR(aead))
                return PTR_ERR(aead);

        tfm->crt_aead.base = aead;
        tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);

        return 0;
}
EXPORT_SYMBOL_GPL(aead_geniv_init);

void aead_geniv_exit(struct crypto_tfm *tfm)
{
        crypto_free_aead(tfm->crt_aead.base);
}
EXPORT_SYMBOL_GPL(aead_geniv_exit);

static int crypto_nivaead_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_AEAD | CRYPTO_ALG_GENIV,
                                      CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
        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;

        geniv = alg->cra_aead.geniv;

        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_aead(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_type == &crypto_aead_type)
                return alg;

        if (!alg->cra_aead.ivsize)
                return alg;

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

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

        type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
        type |= CRYPTO_ALG_TYPE_AEAD;
        mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
        mask |= CRYPTO_ALG_TYPE_MASK;

        alg = crypto_lookup_aead(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_aead);

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

        type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
        type |= CRYPTO_ALG_TYPE_AEAD;
        mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
        mask |= CRYPTO_ALG_TYPE_MASK;

        for (;;) {
                struct crypto_alg *alg;

                alg = crypto_lookup_aead(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_aead_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_aead);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");

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