/*
   * Cryptographic Hash operations.
   * 
   * 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/hash.h>

  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/module.h>

  #include <linux/slab.h>

  #include <linux/seq_file.h>
  
  #include "internal.h"

  static unsigned int crypto_hash_ctxsize(struct crypto_alg *alg, u32 type,
  					u32 mask)

  {
  	return alg->cra_ctxsize;
  }

  static int hash_setkey_unaligned(struct crypto_hash *crt, const u8 *key,
  		                 unsigned int keylen)
  {
  	struct crypto_tfm *tfm = crypto_hash_tfm(crt);
  	struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
  	unsigned long alignmask = crypto_hash_alignmask(crt);
  	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 = alg->setkey(crt, alignbuffer, keylen);

  	memset(alignbuffer, 0, keylen);

  	kfree(buffer);
  	return ret;
  }
  
  static int hash_setkey(struct crypto_hash *crt, const u8 *key,

  		       unsigned int keylen)

  {
  	struct crypto_tfm *tfm = crypto_hash_tfm(crt);
  	struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
  	unsigned long alignmask = crypto_hash_alignmask(crt);
  
  	if ((unsigned long)key & alignmask)
  		return hash_setkey_unaligned(crt, key, keylen);
  
  	return alg->setkey(crt, key, keylen);
  }

  static int hash_async_setkey(struct crypto_ahash *tfm_async, const u8 *key,
  			unsigned int keylen)
  {
  	struct crypto_tfm  *tfm      = crypto_ahash_tfm(tfm_async);
  	struct crypto_hash *tfm_hash = __crypto_hash_cast(tfm);
  	struct hash_alg    *alg      = &tfm->__crt_alg->cra_hash;
  
  	return alg->setkey(tfm_hash, key, keylen);
  }
  
  static int hash_async_init(struct ahash_request *req)
  {
  	struct crypto_tfm *tfm = req->base.tfm;
  	struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
  	struct hash_desc  desc = {
  		.tfm = __crypto_hash_cast(tfm),
  		.flags = req->base.flags,
  	};
  
  	return alg->init(&desc);
  }
  
  static int hash_async_update(struct ahash_request *req)
  {
  	struct crypto_tfm *tfm = req->base.tfm;
  	struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
  	struct hash_desc  desc = {
  		.tfm = __crypto_hash_cast(tfm),
  		.flags = req->base.flags,
  	};
  
  	return alg->update(&desc, req->src, req->nbytes);
  }
  
  static int hash_async_final(struct ahash_request *req)
  {
  	struct crypto_tfm *tfm = req->base.tfm;
  	struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
  	struct hash_desc  desc = {
  		.tfm = __crypto_hash_cast(tfm),
  		.flags = req->base.flags,
  	};
  
  	return alg->final(&desc, req->result);
  }
  
  static int hash_async_digest(struct ahash_request *req)
  {
  	struct crypto_tfm *tfm = req->base.tfm;
  	struct hash_alg   *alg = &tfm->__crt_alg->cra_hash;
  	struct hash_desc  desc = {
  		.tfm = __crypto_hash_cast(tfm),
  		.flags = req->base.flags,
  	};
  
  	return alg->digest(&desc, req->src, req->nbytes, req->result);
  }
  
  static int crypto_init_hash_ops_async(struct crypto_tfm *tfm)
  {
  	struct ahash_tfm *crt = &tfm->crt_ahash;
  	struct hash_alg  *alg = &tfm->__crt_alg->cra_hash;
  
  	crt->init       = hash_async_init;
  	crt->update     = hash_async_update;
  	crt->final      = hash_async_final;
  	crt->digest     = hash_async_digest;
  	crt->setkey     = hash_async_setkey;
  	crt->digestsize = alg->digestsize;

  
  	return 0;
  }
  
  static int crypto_init_hash_ops_sync(struct crypto_tfm *tfm)

  {
  	struct hash_tfm *crt = &tfm->crt_hash;
  	struct hash_alg *alg = &tfm->__crt_alg->cra_hash;

  	crt->init       = alg->init;
  	crt->update     = alg->update;
  	crt->final      = alg->final;
  	crt->digest     = alg->digest;
  	crt->setkey     = hash_setkey;

  	crt->digestsize = alg->digestsize;
  
  	return 0;
  }

  static int crypto_init_hash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
  {
  	struct hash_alg *alg = &tfm->__crt_alg->cra_hash;

  	if (alg->digestsize > PAGE_SIZE / 8)

  		return -EINVAL;
  
  	if ((mask & CRYPTO_ALG_TYPE_HASH_MASK) != CRYPTO_ALG_TYPE_HASH_MASK)
  		return crypto_init_hash_ops_async(tfm);
  	else
  		return crypto_init_hash_ops_sync(tfm);
  }

  static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)

  	__attribute__ ((unused));

  static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
  {
  	seq_printf(m, "type         : hash
  ");
  	seq_printf(m, "blocksize    : %u
  ", alg->cra_blocksize);
  	seq_printf(m, "digestsize   : %u
  ", alg->cra_hash.digestsize);
  }
  
  const struct crypto_type crypto_hash_type = {
  	.ctxsize = crypto_hash_ctxsize,
  	.init = crypto_init_hash_ops,
  #ifdef CONFIG_PROC_FS
  	.show = crypto_hash_show,
  #endif
  };
  EXPORT_SYMBOL_GPL(crypto_hash_type);
  
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Generic cryptographic hash type");