Subversion Repositories test_project

/*

 * Cryptographic API.

 *

 * HMAC: Keyed-Hashing for Message Authentication (RFC2104).

 *

 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>

 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>

 *

 * The HMAC implementation is derived from USAGI.

 * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI

 *

 * 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/algapi.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/scatterlist.h>

#include <linux/slab.h>

#include <linux/string.h>

struct hmac_ctx {

        struct crypto_hash *child;

};

static inline void *align_ptr(void *p, unsigned int align)

{

        return (void *)ALIGN((unsigned long)p, align);

}

static inline struct hmac_ctx *hmac_ctx(struct crypto_hash *tfm)

{

        return align_ptr(crypto_hash_ctx_aligned(tfm) +

                         crypto_hash_blocksize(tfm) * 2 +

                         crypto_hash_digestsize(tfm), sizeof(void *));

}

static int hmac_setkey(struct crypto_hash *parent,

                       const u8 *inkey, unsigned int keylen)

{

        int bs = crypto_hash_blocksize(parent);

        int ds = crypto_hash_digestsize(parent);

        char *ipad = crypto_hash_ctx_aligned(parent);

        char *opad = ipad + bs;

        char *digest = opad + bs;

        struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));

        struct crypto_hash *tfm = ctx->child;

        unsigned int i;

        if (keylen > bs) {

                struct hash_desc desc;

                struct scatterlist tmp;

                int err;

                desc.tfm = tfm;

                desc.flags = crypto_hash_get_flags(parent);

                desc.flags &= CRYPTO_TFM_REQ_MAY_SLEEP;

                sg_init_one(&tmp, inkey, keylen);

                err = crypto_hash_digest(&desc, &tmp, keylen, digest);

                if (err)

                        return err;

                inkey = digest;

                keylen = ds;

        }

        memcpy(ipad, inkey, keylen);

        memset(ipad + keylen, 0, bs - keylen);

        memcpy(opad, ipad, bs);

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

                ipad[i] ^= 0x36;

                opad[i] ^= 0x5c;

        }

        return 0;

}

static int hmac_init(struct hash_desc *pdesc)

{

        struct crypto_hash *parent = pdesc->tfm;

        int bs = crypto_hash_blocksize(parent);

        int ds = crypto_hash_digestsize(parent);

        char *ipad = crypto_hash_ctx_aligned(parent);

        struct hmac_ctx *ctx = align_ptr(ipad + bs * 2 + ds, sizeof(void *));

        struct hash_desc desc;

        struct scatterlist tmp;

        int err;

        desc.tfm = ctx->child;

        desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;

        sg_init_one(&tmp, ipad, bs);

        err = crypto_hash_init(&desc);

        if (unlikely(err))

                return err;

        return crypto_hash_update(&desc, &tmp, bs);

}

static int hmac_update(struct hash_desc *pdesc,

                       struct scatterlist *sg, unsigned int nbytes)

{

        struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);

        struct hash_desc desc;

        desc.tfm = ctx->child;

        desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;

        return crypto_hash_update(&desc, sg, nbytes);

}

static int hmac_final(struct hash_desc *pdesc, u8 *out)

{

        struct crypto_hash *parent = pdesc->tfm;

        int bs = crypto_hash_blocksize(parent);

        int ds = crypto_hash_digestsize(parent);

        char *opad = crypto_hash_ctx_aligned(parent) + bs;

        char *digest = opad + bs;

        struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));

        struct hash_desc desc;

        struct scatterlist tmp;

        int err;

        desc.tfm = ctx->child;

        desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;

        sg_init_one(&tmp, opad, bs + ds);

        err = crypto_hash_final(&desc, digest);

        if (unlikely(err))

                return err;

        return crypto_hash_digest(&desc, &tmp, bs + ds, out);

}

static int hmac_digest(struct hash_desc *pdesc, struct scatterlist *sg,

                       unsigned int nbytes, u8 *out)

{

        struct crypto_hash *parent = pdesc->tfm;

        int bs = crypto_hash_blocksize(parent);

        int ds = crypto_hash_digestsize(parent);

        char *ipad = crypto_hash_ctx_aligned(parent);

        char *opad = ipad + bs;

        char *digest = opad + bs;

        struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));

        struct hash_desc desc;

        struct scatterlist sg1[2];

        struct scatterlist sg2[1];

        int err;

        desc.tfm = ctx->child;

        desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;

        sg_init_table(sg1, 2);

        sg_set_buf(sg1, ipad, bs);

        sg_set_page(&sg1[1], (void *) sg, 0, 0);

        sg_init_table(sg2, 1);

        sg_set_buf(sg2, opad, bs + ds);

        err = crypto_hash_digest(&desc, sg1, nbytes + bs, digest);

        if (unlikely(err))

                return err;

        return crypto_hash_digest(&desc, sg2, bs + ds, out);

}

static int hmac_init_tfm(struct crypto_tfm *tfm)

{

        struct crypto_hash *hash;

        struct crypto_instance *inst = (void *)tfm->__crt_alg;

        struct crypto_spawn *spawn = crypto_instance_ctx(inst);

        struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));

        hash = crypto_spawn_hash(spawn);

        if (IS_ERR(hash))

                return PTR_ERR(hash);

        ctx->child = hash;

        return 0;

}

static void hmac_exit_tfm(struct crypto_tfm *tfm)

{

        struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));

        crypto_free_hash(ctx->child);

}

static void hmac_free(struct crypto_instance *inst)

{

        crypto_drop_spawn(crypto_instance_ctx(inst));

        kfree(inst);

}

static struct crypto_instance *hmac_alloc(struct rtattr **tb)

{

        struct crypto_instance *inst;

        struct crypto_alg *alg;

        int err;

        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);

        if (err)

                return ERR_PTR(err);

        alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_HASH,

                                  CRYPTO_ALG_TYPE_HASH_MASK);

        if (IS_ERR(alg))

                return ERR_PTR(PTR_ERR(alg));

        inst = crypto_alloc_instance("hmac", alg);

        if (IS_ERR(inst))

                goto out_put_alg;

        inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;

        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_hash_type;

        inst->alg.cra_hash.digestsize =

                (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==

                CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :

                                       alg->cra_digest.dia_digestsize;

        inst->alg.cra_ctxsize = sizeof(struct hmac_ctx) +

                                ALIGN(inst->alg.cra_blocksize * 2 +

                                      inst->alg.cra_hash.digestsize,

                                      sizeof(void *));

        inst->alg.cra_init = hmac_init_tfm;

        inst->alg.cra_exit = hmac_exit_tfm;

        inst->alg.cra_hash.init = hmac_init;

        inst->alg.cra_hash.update = hmac_update;

        inst->alg.cra_hash.final = hmac_final;

        inst->alg.cra_hash.digest = hmac_digest;

        inst->alg.cra_hash.setkey = hmac_setkey;

out_put_alg:

        crypto_mod_put(alg);

        return inst;

}

static struct crypto_template hmac_tmpl = {

        .name = "hmac",

        .alloc = hmac_alloc,

        .free = hmac_free,

        .module = THIS_MODULE,

};

static int __init hmac_module_init(void)

{

        return crypto_register_template(&hmac_tmpl);

}

static void __exit hmac_module_exit(void)

{

        crypto_unregister_template(&hmac_tmpl);

}

module_init(hmac_module_init);

module_exit(hmac_module_exit);

MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("HMAC hash algorithm");