117 строки
2.8 KiB
C
117 строки
2.8 KiB
C
/*
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* Cryptographic API.
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*
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* Digest operations.
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*
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <linux/crypto.h>
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#include <linux/mm.h>
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#include <linux/errno.h>
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#include <linux/highmem.h>
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#include <asm/scatterlist.h>
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#include "internal.h"
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static void init(struct crypto_tfm *tfm)
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{
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tfm->__crt_alg->cra_digest.dia_init(tfm);
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}
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static void update(struct crypto_tfm *tfm,
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struct scatterlist *sg, unsigned int nsg)
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{
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unsigned int i;
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unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
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for (i = 0; i < nsg; i++) {
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struct page *pg = sg[i].page;
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unsigned int offset = sg[i].offset;
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unsigned int l = sg[i].length;
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do {
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unsigned int bytes_from_page = min(l, ((unsigned int)
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(PAGE_SIZE)) -
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offset);
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char *src = crypto_kmap(pg, 0);
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char *p = src + offset;
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if (unlikely(offset & alignmask)) {
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unsigned int bytes =
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alignmask + 1 - (offset & alignmask);
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bytes = min(bytes, bytes_from_page);
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tfm->__crt_alg->cra_digest.dia_update(tfm, p,
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bytes);
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p += bytes;
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bytes_from_page -= bytes;
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l -= bytes;
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}
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tfm->__crt_alg->cra_digest.dia_update(tfm, p,
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bytes_from_page);
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crypto_kunmap(src, 0);
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crypto_yield(tfm);
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offset = 0;
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pg++;
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l -= bytes_from_page;
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} while (l > 0);
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}
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}
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static void final(struct crypto_tfm *tfm, u8 *out)
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{
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unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
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if (unlikely((unsigned long)out & alignmask)) {
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unsigned int size = crypto_tfm_alg_digestsize(tfm);
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u8 buffer[size + alignmask];
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u8 *dst = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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tfm->__crt_alg->cra_digest.dia_final(tfm, dst);
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memcpy(out, dst, size);
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} else
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tfm->__crt_alg->cra_digest.dia_final(tfm, out);
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}
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static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
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{
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u32 flags;
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if (tfm->__crt_alg->cra_digest.dia_setkey == NULL)
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return -ENOSYS;
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return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen, &flags);
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}
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static void digest(struct crypto_tfm *tfm,
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struct scatterlist *sg, unsigned int nsg, u8 *out)
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{
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init(tfm);
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update(tfm, sg, nsg);
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final(tfm, out);
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}
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int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
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{
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return flags ? -EINVAL : 0;
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}
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int crypto_init_digest_ops(struct crypto_tfm *tfm)
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{
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struct digest_tfm *ops = &tfm->crt_digest;
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ops->dit_init = init;
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ops->dit_update = update;
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ops->dit_final = final;
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ops->dit_digest = digest;
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ops->dit_setkey = setkey;
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return crypto_alloc_hmac_block(tfm);
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}
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void crypto_exit_digest_ops(struct crypto_tfm *tfm)
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{
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crypto_free_hmac_block(tfm);
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}
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