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![Herbert Xu](/assets/img/avatar_default.png)
This patch makes crypto_alloc_ablkcipher/crypto_grab_skcipher always return algorithms that are capable of generating their own IVs through givencrypt and givdecrypt. Each algorithm may specify its default IV generator through the geniv field. For algorithms that do not set the geniv field, the blkcipher layer will pick a default. Currently it's chainiv for synchronous algorithms and eseqiv for asynchronous algorithms. Note that if these wrappers do not work on an algorithm then that algorithm must specify its own geniv or it can't be used at all. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
342 lines
8.6 KiB
C
342 lines
8.6 KiB
C
/*
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* Asynchronous block chaining cipher operations.
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*
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* This is the asynchronous version of blkcipher.c indicating completion
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* via a callback.
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*
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* Copyright (c) 2006 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/skcipher.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/sched.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_ablkcipher *tfm, const u8 *key,
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unsigned int keylen)
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{
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struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
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unsigned long alignmask = crypto_ablkcipher_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 = cipher->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_ablkcipher *tfm, const u8 *key,
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unsigned int keylen)
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{
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struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
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unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
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if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
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crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
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return -EINVAL;
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}
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if ((unsigned long)key & alignmask)
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return setkey_unaligned(tfm, key, keylen);
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return cipher->setkey(tfm, key, keylen);
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}
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static unsigned int crypto_ablkcipher_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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int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
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{
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return crypto_ablkcipher_encrypt(&req->creq);
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}
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int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
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{
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return crypto_ablkcipher_decrypt(&req->creq);
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}
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static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
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u32 mask)
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{
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struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
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struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
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if (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 = skcipher_null_givencrypt;
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crt->givdecrypt = skcipher_null_givdecrypt;
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}
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crt->base = __crypto_ablkcipher_cast(tfm);
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crt->ivsize = alg->ivsize;
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return 0;
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}
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static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
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__attribute__ ((unused));
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static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
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{
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struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
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seq_printf(m, "type : ablkcipher\n");
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seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
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seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
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seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
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seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
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seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<default>");
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}
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const struct crypto_type crypto_ablkcipher_type = {
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.ctxsize = crypto_ablkcipher_ctxsize,
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.init = crypto_init_ablkcipher_ops,
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#ifdef CONFIG_PROC_FS
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.show = crypto_ablkcipher_show,
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#endif
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};
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EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
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static int no_givdecrypt(struct skcipher_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_givcipher_ops(struct crypto_tfm *tfm, u32 type,
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u32 mask)
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{
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struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
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struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
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if (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;
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crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
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crt->base = __crypto_ablkcipher_cast(tfm);
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crt->ivsize = alg->ivsize;
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return 0;
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}
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static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
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__attribute__ ((unused));
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static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
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{
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struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
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seq_printf(m, "type : givcipher\n");
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seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
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seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
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seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
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seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
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seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<built-in>");
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}
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const struct crypto_type crypto_givcipher_type = {
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.ctxsize = crypto_ablkcipher_ctxsize,
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.init = crypto_init_givcipher_ops,
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#ifdef CONFIG_PROC_FS
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.show = crypto_givcipher_show,
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#endif
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};
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EXPORT_SYMBOL_GPL(crypto_givcipher_type);
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const char *crypto_default_geniv(const struct crypto_alg *alg)
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{
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return alg->cra_flags & CRYPTO_ALG_ASYNC ? "eseqiv" : "chainiv";
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}
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static int crypto_givcipher_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_GIVCIPHER,
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CRYPTO_ALG_TYPE_MASK);
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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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if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
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CRYPTO_ALG_TYPE_BLKCIPHER)
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geniv = alg->cra_blkcipher.geniv;
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else
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geniv = alg->cra_ablkcipher.geniv;
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if (!geniv)
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geniv = crypto_default_geniv(alg);
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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_skcipher(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_flags & CRYPTO_ALG_TYPE_MASK) ==
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CRYPTO_ALG_TYPE_GIVCIPHER)
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return alg;
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if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
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CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
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alg->cra_ablkcipher.ivsize))
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return alg;
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return ERR_PTR(crypto_givcipher_default(alg, type, mask));
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}
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int crypto_grab_skcipher(struct crypto_skcipher_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_skcipher_type(type);
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mask = crypto_skcipher_mask(mask);
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alg = crypto_lookup_skcipher(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_skcipher);
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struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
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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_skcipher_type(type);
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mask = crypto_skcipher_mask(mask);
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for (;;) {
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struct crypto_alg *alg;
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alg = crypto_lookup_skcipher(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_ablkcipher_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_ablkcipher);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Asynchronous block chaining cipher type");
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