d29ce988ae
This patch makes crypto_alloc_aead always return algorithms that is capable of generating their own IVs through givencrypt and givdecrypt. All existing AEAD algorithms already do. New ones must either supply their own or specify a generic IV generator with the geniv field. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
486 lines
12 KiB
C
486 lines
12 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/internal/aead.h>
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#include <linux/err.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/rtnetlink.h>
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#include <linux/slab.h>
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#include <linux/seq_file.h>
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#include "internal.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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struct aead_tfm *crt = crypto_aead_crt(tfm);
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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(crt->base, authsize);
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if (err)
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return err;
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}
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crypto_aead_crt(crt->base)->authsize = authsize;
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crt->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 no_givcrypt(struct aead_givcrypt_request *req)
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{
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return -ENOSYS;
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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 = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
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alg->setkey : setkey;
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crt->encrypt = alg->encrypt;
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crt->decrypt = alg->decrypt;
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crt->givencrypt = alg->givencrypt ?: no_givcrypt;
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crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
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crt->base = __crypto_aead_cast(tfm);
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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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seq_printf(m, "geniv : %s\n", aead->geniv ?: "<built-in>");
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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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static int aead_null_givencrypt(struct aead_givcrypt_request *req)
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{
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return crypto_aead_encrypt(&req->areq);
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}
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static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
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{
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return crypto_aead_decrypt(&req->areq);
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}
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static int crypto_init_nivaead_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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if (!alg->ivsize) {
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crt->givencrypt = aead_null_givencrypt;
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crt->givdecrypt = aead_null_givdecrypt;
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}
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crt->base = __crypto_aead_cast(tfm);
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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_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
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__attribute__ ((unused));
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static void crypto_nivaead_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 : nivaead\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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seq_printf(m, "geniv : %s\n", aead->geniv);
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}
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const struct crypto_type crypto_nivaead_type = {
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.ctxsize = crypto_aead_ctxsize,
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.init = crypto_init_nivaead_ops,
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#ifdef CONFIG_PROC_FS
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.show = crypto_nivaead_show,
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#endif
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};
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EXPORT_SYMBOL_GPL(crypto_nivaead_type);
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static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
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const char *name, u32 type, u32 mask)
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{
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struct crypto_alg *alg;
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int err;
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type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
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type |= CRYPTO_ALG_TYPE_AEAD;
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mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;
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alg = crypto_alg_mod_lookup(name, type, mask);
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if (IS_ERR(alg))
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return PTR_ERR(alg);
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err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
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crypto_mod_put(alg);
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return err;
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}
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struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
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struct rtattr **tb, u32 type,
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u32 mask)
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{
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const char *name;
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struct crypto_aead_spawn *spawn;
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struct crypto_attr_type *algt;
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struct crypto_instance *inst;
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struct crypto_alg *alg;
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int err;
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algt = crypto_get_attr_type(tb);
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err = PTR_ERR(algt);
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if (IS_ERR(algt))
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return ERR_PTR(err);
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if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
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algt->mask)
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return ERR_PTR(-EINVAL);
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name = crypto_attr_alg_name(tb[1]);
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err = PTR_ERR(name);
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if (IS_ERR(name))
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return ERR_PTR(err);
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inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
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if (!inst)
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return ERR_PTR(-ENOMEM);
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spawn = crypto_instance_ctx(inst);
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/* Ignore async algorithms if necessary. */
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mask |= crypto_requires_sync(algt->type, algt->mask);
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crypto_set_aead_spawn(spawn, inst);
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err = crypto_grab_nivaead(spawn, name, type, mask);
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if (err)
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goto err_free_inst;
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alg = crypto_aead_spawn_alg(spawn);
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err = -EINVAL;
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if (!alg->cra_aead.ivsize)
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goto err_drop_alg;
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/*
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* This is only true if we're constructing an algorithm with its
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* default IV generator. For the default generator we elide the
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* template name and double-check the IV generator.
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*/
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if (algt->mask & CRYPTO_ALG_GENIV) {
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if (strcmp(tmpl->name, alg->cra_aead.geniv))
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goto err_drop_alg;
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memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
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memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
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CRYPTO_MAX_ALG_NAME);
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} else {
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err = -ENAMETOOLONG;
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if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
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"%s(%s)", tmpl->name, alg->cra_name) >=
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CRYPTO_MAX_ALG_NAME)
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goto err_drop_alg;
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if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
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"%s(%s)", tmpl->name, alg->cra_driver_name) >=
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CRYPTO_MAX_ALG_NAME)
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goto err_drop_alg;
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}
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inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
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inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
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inst->alg.cra_priority = alg->cra_priority;
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inst->alg.cra_blocksize = alg->cra_blocksize;
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inst->alg.cra_alignmask = alg->cra_alignmask;
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inst->alg.cra_type = &crypto_aead_type;
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inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
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inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
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inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
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inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
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inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
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inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
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inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
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out:
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return inst;
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err_drop_alg:
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crypto_drop_aead(spawn);
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err_free_inst:
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kfree(inst);
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inst = ERR_PTR(err);
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goto out;
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}
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EXPORT_SYMBOL_GPL(aead_geniv_alloc);
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void aead_geniv_free(struct crypto_instance *inst)
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{
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crypto_drop_aead(crypto_instance_ctx(inst));
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kfree(inst);
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}
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EXPORT_SYMBOL_GPL(aead_geniv_free);
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int aead_geniv_init(struct crypto_tfm *tfm)
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{
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struct crypto_instance *inst = (void *)tfm->__crt_alg;
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struct crypto_aead *aead;
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aead = crypto_spawn_aead(crypto_instance_ctx(inst));
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if (IS_ERR(aead))
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return PTR_ERR(aead);
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tfm->crt_aead.base = aead;
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tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
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return 0;
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}
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EXPORT_SYMBOL_GPL(aead_geniv_init);
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void aead_geniv_exit(struct crypto_tfm *tfm)
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{
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crypto_free_aead(tfm->crt_aead.base);
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}
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EXPORT_SYMBOL_GPL(aead_geniv_exit);
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static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
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{
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struct rtattr *tb[3];
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struct {
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struct rtattr attr;
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struct crypto_attr_type data;
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} ptype;
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struct {
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struct rtattr attr;
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struct crypto_attr_alg data;
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} palg;
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struct crypto_template *tmpl;
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struct crypto_instance *inst;
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struct crypto_alg *larval;
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const char *geniv;
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int err;
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larval = crypto_larval_lookup(alg->cra_driver_name,
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CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
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CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
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err = PTR_ERR(larval);
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if (IS_ERR(larval))
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goto out;
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err = -EAGAIN;
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if (!crypto_is_larval(larval))
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goto drop_larval;
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ptype.attr.rta_len = sizeof(ptype);
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ptype.attr.rta_type = CRYPTOA_TYPE;
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ptype.data.type = type | CRYPTO_ALG_GENIV;
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/* GENIV tells the template that we're making a default geniv. */
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ptype.data.mask = mask | CRYPTO_ALG_GENIV;
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tb[0] = &ptype.attr;
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palg.attr.rta_len = sizeof(palg);
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palg.attr.rta_type = CRYPTOA_ALG;
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/* Must use the exact name to locate ourselves. */
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memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
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tb[1] = &palg.attr;
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tb[2] = NULL;
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geniv = alg->cra_aead.geniv;
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tmpl = crypto_lookup_template(geniv);
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err = -ENOENT;
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if (!tmpl)
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goto kill_larval;
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inst = tmpl->alloc(tb);
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err = PTR_ERR(inst);
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if (IS_ERR(inst))
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goto put_tmpl;
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if ((err = crypto_register_instance(tmpl, inst))) {
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tmpl->free(inst);
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goto put_tmpl;
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}
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/* Redo the lookup to use the instance we just registered. */
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err = -EAGAIN;
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put_tmpl:
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crypto_tmpl_put(tmpl);
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kill_larval:
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crypto_larval_kill(larval);
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drop_larval:
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crypto_mod_put(larval);
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out:
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crypto_mod_put(alg);
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return err;
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}
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static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
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u32 mask)
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{
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struct crypto_alg *alg;
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alg = crypto_alg_mod_lookup(name, type, mask);
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if (IS_ERR(alg))
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return alg;
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if (alg->cra_type == &crypto_aead_type)
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return alg;
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if (!alg->cra_aead.ivsize)
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return alg;
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return ERR_PTR(crypto_nivaead_default(alg, type, mask));
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}
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int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
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u32 type, u32 mask)
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{
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struct crypto_alg *alg;
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int err;
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type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
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type |= CRYPTO_ALG_TYPE_AEAD;
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mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
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mask |= CRYPTO_ALG_TYPE_MASK;
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alg = crypto_lookup_aead(name, type, mask);
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if (IS_ERR(alg))
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return PTR_ERR(alg);
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err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
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crypto_mod_put(alg);
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return err;
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}
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EXPORT_SYMBOL_GPL(crypto_grab_aead);
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struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
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{
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struct crypto_tfm *tfm;
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int err;
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type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
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type |= CRYPTO_ALG_TYPE_AEAD;
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mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
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mask |= CRYPTO_ALG_TYPE_MASK;
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for (;;) {
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struct crypto_alg *alg;
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alg = crypto_lookup_aead(alg_name, type, mask);
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if (IS_ERR(alg)) {
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err = PTR_ERR(alg);
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goto err;
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}
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tfm = __crypto_alloc_tfm(alg, type, mask);
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if (!IS_ERR(tfm))
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return __crypto_aead_cast(tfm);
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crypto_mod_put(alg);
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err = PTR_ERR(tfm);
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err:
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if (err != -EAGAIN)
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break;
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if (signal_pending(current)) {
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err = -EINTR;
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break;
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}
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}
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return ERR_PTR(err);
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}
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EXPORT_SYMBOL_GPL(crypto_alloc_aead);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
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