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ee7564166d
When the final result location is unaligned, we store the digest in a temporary buffer before copying it to the final location. Currently that buffer sits on the stack. This patch moves it to an area in the tfm, just like the CBC IV buffer. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
126 lines
3.1 KiB
C
126 lines
3.1 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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struct digest_alg *digest = &tfm->__crt_alg->cra_digest;
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if (unlikely((unsigned long)out & alignmask)) {
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unsigned long align = alignmask + 1;
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unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
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u8 *dst = (u8 *)ALIGN(addr, align) +
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ALIGN(tfm->__crt_alg->cra_ctxsize, align);
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digest->dia_final(tfm, dst);
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memcpy(out, dst, digest->dia_digestsize);
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} else
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digest->dia_final(tfm, out);
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}
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static int nosetkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
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{
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tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
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return -ENOSYS;
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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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tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
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return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
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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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struct digest_alg *dalg = &tfm->__crt_alg->cra_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 = dalg->dia_setkey ? setkey : nosetkey;
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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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