7ba683a6de
As it is authsize is an algorithm paramter which cannot be changed at run-time. This is inconvenient because hardware that implements such algorithms would have to register each authsize that they support separately. Since authsize is a property common to all AEAD algorithms, we can add a function setauthsize that sets it at run-time, just like setkey. This patch does exactly that and also changes authenc so that authsize is no longer a parameter of its template. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
120 lines
3.1 KiB
C
120 lines
3.1 KiB
C
/*
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* AEAD: Authenticated Encryption with Associated Data
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*
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* This file provides API support for AEAD algorithms.
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*
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* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.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 <crypto/algapi.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/seq_file.h>
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static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
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unsigned int keylen)
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{
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struct aead_alg *aead = crypto_aead_alg(tfm);
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unsigned long alignmask = crypto_aead_alignmask(tfm);
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int ret;
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u8 *buffer, *alignbuffer;
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unsigned long absize;
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absize = keylen + alignmask;
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buffer = kmalloc(absize, GFP_ATOMIC);
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if (!buffer)
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return -ENOMEM;
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alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
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memcpy(alignbuffer, key, keylen);
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ret = aead->setkey(tfm, alignbuffer, keylen);
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memset(alignbuffer, 0, keylen);
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kfree(buffer);
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return ret;
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}
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static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
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{
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struct aead_alg *aead = crypto_aead_alg(tfm);
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unsigned long alignmask = crypto_aead_alignmask(tfm);
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if ((unsigned long)key & alignmask)
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return setkey_unaligned(tfm, key, keylen);
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return aead->setkey(tfm, key, keylen);
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}
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int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
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{
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int err;
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if (authsize > crypto_aead_alg(tfm)->maxauthsize)
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return -EINVAL;
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if (crypto_aead_alg(tfm)->setauthsize) {
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err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
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if (err)
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return err;
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}
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crypto_aead_crt(tfm)->authsize = authsize;
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return 0;
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}
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EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
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static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
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u32 mask)
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{
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return alg->cra_ctxsize;
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}
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static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
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{
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struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
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struct aead_tfm *crt = &tfm->crt_aead;
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if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
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return -EINVAL;
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crt->setkey = setkey;
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crt->encrypt = alg->encrypt;
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crt->decrypt = alg->decrypt;
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crt->ivsize = alg->ivsize;
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crt->authsize = alg->maxauthsize;
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return 0;
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}
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static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
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__attribute__ ((unused));
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static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
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{
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struct aead_alg *aead = &alg->cra_aead;
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seq_printf(m, "type : aead\n");
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seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
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seq_printf(m, "ivsize : %u\n", aead->ivsize);
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seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
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}
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const struct crypto_type crypto_aead_type = {
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.ctxsize = crypto_aead_ctxsize,
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.init = crypto_init_aead_ops,
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#ifdef CONFIG_PROC_FS
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.show = crypto_aead_show,
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#endif
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};
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EXPORT_SYMBOL_GPL(crypto_aead_type);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
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